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Gruslova AB, Singh S, Hoyt T, Vela D, Vengrenyuk Y, Buja LM, Litovsky S, Michalek J, Maehara A, Kini A, Akasaka T, Garcia-Garcia HM, Jang IK, Dijkstra J, Raber L, Milner TE, Feldman MD. Accuracy of OCT Core Labs in Identifying Vulnerable Plaque. JACC Cardiovasc Imaging 2024; 17:448-450. [PMID: 37943235 DOI: 10.1016/j.jcmg.2023.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 09/26/2023] [Accepted: 10/12/2023] [Indexed: 11/10/2023]
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Teichman JMH, Katta N, Milner TE. Editorial Comment. J Urol 2024; 211:454. [PMID: 38224054 DOI: 10.1097/ju.0000000000003833.01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Accepted: 12/14/2023] [Indexed: 01/16/2024]
Affiliation(s)
- Joel M H Teichman
- Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Nitesh Katta
- Beckman Laser Institute, University of California, Irvine, Irvine, California
| | - Thomas E Milner
- Beckman Laser Institute, University of California, Irvine, Irvine, California
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Gruslova AB, Inanc IH, Cilingiroglu M, Katta N, Milner TE, Feldman MD. Review of intravascular lithotripsy for treating coronary, peripheral artery, and valve calcifications. Catheter Cardiovasc Interv 2024; 103:295-307. [PMID: 38091341 DOI: 10.1002/ccd.30933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 11/29/2023] [Accepted: 12/03/2023] [Indexed: 01/31/2024]
Abstract
Management of intracoronary calcium (ICC) continues to be a challenge for interventional cardiologists. There have been significant advances in calcium treatment devices. However, there still exists a knowledge gap regarding which devices to choose for the treatment of ICC. The purpose of this manuscript is to review the principles of intravascular lithotripsy (IVL) and clinical data. The technique of IVL will then be compared to alternative calcium treatment devices. Clinical data will be reviewed concerning the treatment of coronary, peripheral artery and valvular calcifications. Controversies to be discussed include how to incorporate IVL into your practice, what is the best approach for treating calcium subtypes, how to approach under-expanded stents, what is the ideal technique for performing IVL, how safe is IVL, whether imaging adds value when performing IVL, and how IVL fits into a treatment program for peripheral arteries and calcified valves.
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Affiliation(s)
- Aleksandra B Gruslova
- Division of Cardiology, Department of Medicine, University of Texas Health at San Antonio, San Antonio, Texas, USA
| | - Ibrahim H Inanc
- Department of Cardiology, Kırıkkale Yuksek Ihtisas Hospital, Kırıkkale, Turkey
| | - Mehmet Cilingiroglu
- Division of Cardiology, Department of Medicine, University of Texas Health at San Antonio, San Antonio, Texas, USA
- MD Anderson Cancer Center, University of Texas in Houston, Houston, Texas, USA
| | - Nitesh Katta
- Beckman Laser Institute and Medical Clinic, University of California at Irvine, Irvine, California, USA
| | - Thomas E Milner
- Beckman Laser Institute and Medical Clinic, University of California at Irvine, Irvine, California, USA
| | - Marc D Feldman
- Division of Cardiology, Department of Medicine, University of Texas Health at San Antonio, San Antonio, Texas, USA
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Gruslova AB, Katta N, Nolen D, Jenney S, Vela D, Buja M, Cilingiroglu M, Seddighi Y, Han HC, Milner TE, Feldman MD. Intravascular laser lithotripsy for calcium fracture in human coronary arteries. EUROINTERVENTION 2023; 19:e913-e922. [PMID: 38060282 PMCID: PMC10722992 DOI: 10.4244/eij-d-23-00487] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 10/11/2023] [Indexed: 12/08/2023]
Abstract
BACKGROUND Electrical intravascular lithotripsy (E-IVL) uses shock waves to fracture calcified plaque. AIMS We aimed to demonstrate the ability of laser IVL (L-IVL) to fracture calcified plaques in ex vivo human coronary arteries and to identify and evaluate the mechanisms for increased vessel compliance. METHODS Shock waves were generated by a Ho:YAG (Holmium: yttrium-aluminium-garnet) laser (2 J, 5 Hz) and recorded by a high-speed camera and pressure sensor. Tests were conducted on phantoms and 19 fresh human coronary arteries. Before and after L-IVL, arterial compliance and optical coherence tomography (OCT) pullbacks were recorded, followed by histology. Additionally, microcomputed tomography (micro-CT) and scanning electron microscopy (SEM) were performed. Finite element models (FEM) were utilised to examine the mechanism of L-IVL. RESULTS Phantom cracks were obtained using 230 μm and 400 μm fibres with shock-wave pressures of 84±5.0 atm and 62±0.4 atm, respectively. Post-lithotripsy, calcium plaque modifications, including fractures and debonding, were identified by OCT in 78% of the ex vivo calcified arteries (n=19). Histological analysis revealed calcium microfractures (38.7±10.4 μm width) in 57% of the arteries which were not visible by OCT. Calcium microfractures were verified by micro-CT and SEM. The lumen area increased from 2.9±0.4 to 4.3±0.8 mm2 (p<0.01). Arterial compliance increased by 2.3±0.6 atm/ml (p<0.05). FEM simulations suggest that debonding and intimal tears are additional mechanisms for increased arterial compliance. CONCLUSIONS L-IVL has the capability to increase calcified coronary artery compliance by multiple mechanisms.
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Affiliation(s)
| | - Nitesh Katta
- Beckman Laser Institute and Medical Clinic, University of California at Irvine, Irvine, CA, USA
| | - Drew Nolen
- Department of Medicine, University of Texas Health, San Antonio, TX, USA
| | - Scott Jenney
- Beckman Laser Institute and Medical Clinic, University of California at Irvine, Irvine, CA, USA
| | | | | | | | - Yasamin Seddighi
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Hai Chao Han
- Department of Mechanical Engineering, The University of Texas at San Antonio, San Antonio, TX, USA
| | - Thomas E Milner
- Beckman Laser Institute and Medical Clinic, University of California at Irvine, Irvine, CA, USA
| | - Marc D Feldman
- Department of Medicine, University of Texas Health, San Antonio, TX, USA
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Li Y, Blakeley J, Ly I, Berman Y, Lau J, Wolkenstein P, Bergqvist C, Jia W, Milner TE, Katta N, Durkin AJ, Kennedy GT, Rowland R, Romo CG, Fleming J, Kelly KM. Current and Emerging Imaging Techniques for Neurofibromatosis Type 1-Associated Cutaneous Neurofibromas. J Invest Dermatol 2023:S0022-202X(23)01988-7. [PMID: 37330718 DOI: 10.1016/j.jid.2023.03.1681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 02/25/2023] [Accepted: 03/08/2023] [Indexed: 06/19/2023]
Abstract
A consistent set of measurement techniques must be applied to reliably and reproducibly evaluate the efficacy of treatments for cutaneous neurofibromas (cNFs) in people with neurofibromatosis type 1 (NF1). cNFs are neurocutaneous tumors that are the most common tumor in people with NF1 and represent an area of unmet clinical need. This review presents the available data regarding approaches in use or development to identify, measure, and track cNFs, including calipers, digital imaging, and high-frequency ultrasound sonography. We also describe emerging technologies such as spatial frequency domain imaging and the application of imaging modalities such as optical coherence tomography that may enable the detection of early cNFs and prevention of tumor-associated morbidity.
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Affiliation(s)
- Yingjoy Li
- Department of Dermatology, School of Medicine, University of California, Irvine, California, USA
| | - Jaishri Blakeley
- Comprehensive Neurofibromatosis Center, Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Ina Ly
- Stephen E. and Catherine Pappas Center for Neuro-Oncology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Yemima Berman
- Department of Clinical Genetics, Royal North Shore Hospital, St Leonards, Australia
| | - Jonathan Lau
- Department of Clinical Genetics, Royal North Shore Hospital, St Leonards, Australia; Sydney Medical School, The University of Sydney, Camperdown, Australia
| | - Pierre Wolkenstein
- Faculty of Medicine and Health, Université Paris-Est Créteil Val de Marne, Créteil, France; Department of Dermatology, National Referral Center for Neurofibromatoses, Henri-Mondor Hospital, Assistance Publique-Hôpital Paris (AP-HP), Créteil, France
| | - Christina Bergqvist
- Department of Dermatology, National Referral Center for Neurofibromatoses, Henri-Mondor Hospital, Assistance Publique-Hôpital Paris (AP-HP), Créteil, France
| | - Wangcun Jia
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, California, USA
| | - Thomas E Milner
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, California, USA; Department of Biomedical Engineering, University of California, Irvine, California, USA
| | - Nitesh Katta
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, California, USA
| | - Anthony J Durkin
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, California, USA; Department of Biomedical Engineering, University of California, Irvine, California, USA
| | - Gordon T Kennedy
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, California, USA
| | - Rebecca Rowland
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, California, USA
| | - Carlos G Romo
- Comprehensive Neurofibromatosis Center, Department of Neurology, Johns Hopkins University, Baltimore, Maryland, USA
| | - Jane Fleming
- Department of Clinical Genetics, Royal North Shore Hospital, St Leonards, Australia
| | - Kristen M Kelly
- Department of Dermatology, School of Medicine, University of California, Irvine, California, USA; Beckman Laser Institute & Medical Clinic, University of California, Irvine, California, USA.
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King JB, Katta N, Parekh SH, Milner TE, Tunnell JW. Erratum: Tissue harvest with a laser microbiopsy (Erratum). J Biomed Opt 2023; 28:029801. [PMID: 36864902 PMCID: PMC9973560 DOI: 10.1117/1.jbo.28.2.029801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
[This corrects the article DOI: 10.1117/1.JBO.27.12.125001.].
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Affiliation(s)
- Jason B King
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Nitesh Katta
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Sapun H Parekh
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Thomas E Milner
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - James W Tunnell
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
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King JB, Katta N, Parekh SH, Milner TE, Tunnell JW. Tissue harvest with a laser microbiopsy. J Biomed Opt 2022; 27:125001. [PMID: 36530344 PMCID: PMC9749420 DOI: 10.1117/1.jbo.27.12.125001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Accepted: 11/22/2022] [Indexed: 06/17/2023]
Abstract
Significance Traditional pathology workflow suffers from limitations including biopsy invasiveness, small fraction of large tissue samples being analyzed, and complex and time-consuming processing. Aim We address limitations of conventional pathology workflow through development of a laser microbiopsy device for minimally invasive harvest of sub-microliter tissue volumes. Laser microbiopsy combined with rapid diagnostic methods, such as virtual hematoxylin and eosin (H&E) imaging has potential to provide rapid minimally invasive tissue diagnosis. Approach Laser microbiopsies were harvested using an annular shaped Ho:YAG laser beam focused onto the tissue surface. As the annulus was ablated, the tissue section in the center of the annulus was ejected and collected directly onto a glass slide for analysis. Cryogen spray cooling was used before and after laser harvest to limit thermal damage. Microbiopsies were collected from porcine skin and kidney. Harvested microbiopsies were imaged with confocal microscopy and digitally false colored to provide virtual H&E images. Results Microbiopsies were successfully harvested from porcine skin and kidney. Computational and experimental results show the benefit of cryogen pre- and post-cooling to limit thermal damage. Virtual H&E images of microbiopsies retained observable cellular features including cell nuclei. Conclusions Laser microbiopsy with virtual H&E imaging shows promise as a potential rapid and minimally invasive tool for biopsy and diagnosis.
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Affiliation(s)
- Jason B. King
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Nitesh Katta
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - Sapun H. Parekh
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
| | - Thomas E. Milner
- University of California Irvine, Beckman Laser Institute and Medical Clinic, Irvine, California, United States
| | - James W. Tunnell
- The University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
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Katta N, Estrada AD, McElroy AB, Milner TE. Er:YAG laser brain surgery with vascular specific coagulation. Lasers Surg Med 2022; 54:1107-1115. [PMID: 35946396 DOI: 10.1002/lsm.23591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 07/14/2022] [Accepted: 07/21/2022] [Indexed: 11/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Erbium:yttrium-aluminum-garnet (Er:YAG) laser ablation can effectively resect water-bearing tissues. Application of Er:YAG resection in neurosurgery is complicated by unpredictable bleeding in surgical field. Recently, an integrated theranostic system combining a dual-wavelength laser surgery system using a thulium (Tm) fiber-laser for coagulation and Er:YAG for resection, combined with optical coherence tomography (OCT) guidance was demonstrated for the in vivo resection of tumor tissue. However, lateral thermal spread in the range of 100 seconds of micrometers is common due to lack of vascular specificity using a Tm fiber-laser for coagulation. In this study, a vascular specific ytterbium (Yb) fiber-laser is utilized for enhanced photocoagulation during in vivo neurosurgery improving the precision of Er:YAG tissue resection with minimal lateral thermal spread. METHODS Mice underwent stereotactic laser surgery with the proposed Yb/Er:YAG dual wavelength vascular specific neurosurgery in vivo. An OCT system (wavelength range 1310 ± 70 nm) and OCT derived angiography images were used to record cortical images to confirm the coagulation of blood vessels and guide subsequent Er:YAG resection steps. After the laser surgery, mice were killed, and histological analysis was carried out using hematoxylin and eosin staining and Nissl staining to compare the lateral thermal spread with our previously reported Tm/Er:YAG neurosurgery where a continuous wave Tm fiber-laser was used for coagulation. RESULTS Coagulation scheme using a Yb fiber-laser allowed stoppage of blood flow in disparately sized blood vessels encountered in the mice brain. Histological analysis of murine brain slices post Yb/Er:YAG laser surgery yielded lower thermal spread compared with Tm/Er:YAG laser surgery, maximizing the efficiency in both hemostasis (blood flow stoppage) and maximizing tissue ablation efficiency with minimal residual thermal damage zone. CONCLUSION In this study, a vascular specific coagulation scheme with Yb/Er:YAG dual-wavelength surgery is presented for neurosurgery. Additionally, Yb/Er:YAG study results are compared with that of a tissue coagulation approach in Tm/Er:YAG surgery previously reported to highlight improved coagulation, reduced nonspecific thermal damage and limited lateral thermal spread. Experimental results suggest that the developed dual-wavelength laser system can effectively resect neural tissues with high localization, minimal lateral thermal spread at the micrometer level while maintaining a bloodless surgical field.
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Affiliation(s)
- Nitesh Katta
- Beckman Laser Institute, University of California at Irvine, East Irvine, California, USA
| | - Arnold D Estrada
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Austin B McElroy
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas, USA
| | - Thomas E Milner
- Beckman Laser Institute, University of California at Irvine, East Irvine, California, USA
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Katta N, Estrada AD, McErloy AB, Milner TE. Fiber-laser platform for precision brain surgery. Biomed Opt Express 2022; 13:1985-1994. [PMID: 35519278 PMCID: PMC9045916 DOI: 10.1364/boe.449312] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 02/20/2022] [Accepted: 02/21/2022] [Indexed: 06/14/2023]
Abstract
Minimally invasive neurological surgeries are increasingly being sought after for treatment in neurological pathologies and oncology. A critical limitation in these minimally invasive procedures is lack of specialized tools that allow for space-time controlled delivery of sufficient energy for coagulation and cutting of tissue. Advent of fiber-lasers provide high average power with improved beam quality (lower M2), biocompatible silica fiber delivery, reduced cost of manufacturing, and radiant output stability over long operating periods. Despite these advancements, no fiber-laser based surgical tools are currently available for tissue resection in vivo. Here we demonstrate a first to our knowledge, fiber-laser platform for performing precise brain surgery in a murine brain model. In this study, our primary aims were to first demonstrate efficacy of fiber-lasers in performing precise blood-less surgery in a murine brain with limited non-specific thermal damage. Second, fiber-lasers' ability to deliver radiant energy through biocompatible silica fibers was explored in a murine brain model for blood less resection. A bench-top optical coherence tomography (OCT) guided fiber-laser platform was constructed with a stereotactic stage for performing precision brain surgery. A pulsed quasi-continuous wave ytterbium (Yb) fiber-laser (1.07 µm) was used to perform vascular specific coagulation while a pulsed nanosecond thulium fiber-laser (1.94 µm) was used to conduct bloodless cutting, all under the guidance of a swept-source OCT system centered at 1310 +/- 70 nm. Specialty linear and circular cuts were made in an in vivo murine brain for bloodless brain tissue resection. The two fiber-lasers were combined into a single biocompatible silica fiber to conduct brain surgery resection under the bench-top OCT system's imaging microscope. Vascular specific coagulation was demonstrated in all five mice studied. Bloodless linear cuts and point cuts were demonstrated in vivo. Histologically, thermal injury was measured to be less than 100 µm while a removal rate of close to 5 mm3/s was achieved with an average Tm fiber-laser power of 15 W. To the authors' knowledge, this is the first demonstration of a fiber-laser platform for conducting in vivo bloodless brain tissue resection with a pulsed thulium (Tm) fiber-laser and a quasi-continuous wave (QCW) Yb fiber-laser. The demonstrated fiber-laser platform, if successfully configured for use in the operating room (OR), can provide surgeons a tool for rapid removal of tissue while making surgical resections of brain regions more precise, and can be basis for a flexible cutting tool capable of reaching hard-to-operate regions.
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Affiliation(s)
- Nitesh Katta
- Beckman Laser Institute, University of California at Irvine, East Irvine, CA 92617, USA
| | - Arnoldo D. Estrada
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Austin B. McErloy
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Thomas E. Milner
- Beckman Laser Institute, University of California at Irvine, East Irvine, CA 92617, USA
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Milner TE, van Gemert MJC, Duco Jansen E. Ashley James Welch (A.J.). Lasers Surg Med 2022; 54:201. [PMID: 35049046 DOI: 10.1002/lsm.23520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 01/07/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Thomas E Milner
- Department of Biomedical Engineering, UC Irvine, Irvine, CA.,Department of Surgery, UC Irvine, Irvine, CA.,Beckman Laser Institute & Medical Clinic, UC Irvine, Irvine, CA
| | - Martin J C van Gemert
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Centers, Amsterdam, The Netherlands
| | - E Duco Jansen
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN.,Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN.,Vanderbilt Biophotonics Center - Vanderbilt University, Nashville, TN
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Abstract
Introduction: This study aimed at answering three research questions: (1) Under the experimental conditions studied, what is the dominant mechanism of Holmium:YAG lithotripsy with or without pulse modulation? (2) Under what circumstances can laser pulse modulation increase crater volume of stone ablation per joule of emitted radiant energy? (3) Are BegoStone phantoms a suitable model for laser lithotripsy studies? Materials and Methods: The research questions were addressed by ablation experiments with BegoStone phantoms and native stones. Experiments were performed under three stone conditions: dry stones in air, hydrated stones in air, and hydrated stones in water. Single pulses with and without pulse modulation were applied. For each pulse mode, temporal profile, transmission through 1 mm water, and cavitation bubble collapse pressures were measured and compared. For each stone condition and pulse mode, stones were ablated with a fiber separation distance of 1 mm and crater volumes were measured using optical coherence tomography. Results: Pulses with and without pulse modulation had high (>80%) transmission through 1 mm of water. Pulses without pulse modulation generated much higher peak pressures than those with pulse modulation (62.3 vs 11.4 bar). Pulse modulation resulted in similar or larger craters than without pulse modulation. Trends in BegoStone crater volumes differed from trends in native stones. Conclusions: This results of this study suggest that the dominant mechanism is photothermal with possible photoacoustic contributions for some stone compositions. Pulse modulation can increase ablation volume per joule of emitted radiant energy, but the effect may be composition specific. BegoStones showed unique infrared ablation characteristics compared with native stones and are not a suitable model for laser lithotripsy studies.
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Affiliation(s)
- Jason B King
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Nitesh Katta
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California, USA
| | - Joel M H Teichman
- St. Paul's Hospital, Vancouver, Canada
- Department of Urologic Sciences, The University of British Columbia, Vancouver, Canada
| | - James W Tunnell
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas, USA
| | - Thomas E Milner
- Beckman Laser Institute and Medical Clinic, University of California Irvine, Irvine, California, USA
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12
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Gruslova AB, Katta N, Cabe AG, Jenney SF, Valvano JW, Phillips TB, McElroy AB, LaSalle RK, Zahedivash A, Truskett VN, Viswanathan N, Feldman MD, Wettstein RB, Milner TE, Derdak S. Data automated bag breathing unit for COVID-19 ventilator shortages. Intensive Care Med Exp 2021; 9:54. [PMID: 34657982 PMCID: PMC8520856 DOI: 10.1186/s40635-021-00419-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Accepted: 09/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The COVID-19 pandemic has caused a global mechanical ventilator shortage for treatment of severe acute respiratory failure. Development of novel breathing devices has been proposed as a low cost, rapid solution when full-featured ventilators are unavailable. Here we report the design, bench testing and preclinical results for an 'Automated Bag Breathing Unit' (ABBU). Output parameters were validated with mechanical test lungs followed by animal model testing. RESULTS The ABBU design uses a programmable motor-driven wheel assembled for adult resuscitation bag-valve compression. ABBU can control tidal volume (200-800 ml), respiratory rate (10-40 bpm), inspiratory time (0.5-1.5 s), assist pressure sensing (- 1 to - 20 cm H2O), manual PEEP valve (0-20 cm H2O). All set values are displayed on an LCD screen. Bench testing with lung simulators (Michigan 1600, SmartLung 2000) yielded consistent tidal volume delivery at compliances of 20, 40 and 70 (mL/cm H2O). The delivered fraction of inspired oxygen (FiO2) decreased with increasing minute ventilation (VE), from 98 to 47% when VE was increased from 4 to 16 L/min using a fixed oxygen flow source of 5 L/min. ABBU was tested in Berkshire pigs (n = 6, weight of 50.8 ± 2.6 kg) utilizing normal lung model and saline lavage induced lung injury. Arterial blood gases were measured following changes in tidal volume (200-800 ml), respiratory rate (10-40 bpm), and PEEP (5-20 cm H2O) at baseline and after lung lavage. Physiological levels of PaCO2 (≤ 40 mm Hg [5.3 kPa]) were achieved in all animals at baseline and following lavage injury. PaO2 increased in lavage injured lungs in response to incremental PEEP (5-20 cm H2O) (p < 0.01). At fixed low oxygen flow rates (5 L/min), delivered FiO2 decreased with increased VE. CONCLUSIONS ABBU provides oxygenation and ventilation across a range of parameter settings that may potentially provide a low-cost solution to ventilator shortages. A clinical trial is necessary to establish safety and efficacy in adult patients with diverse etiologies of respiratory failure.
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Affiliation(s)
- Aleksandra B Gruslova
- Department of Medicine, UT Health San Antonio, 7703 Floyd Curl Drive, DTL 5.532U, San Antonio, TX, 78229, USA.
| | - Nitesh Katta
- Beckman Laser Institute, The University of California Irvine, Irvine, CA, USA
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | - Andrew G Cabe
- Department of Medicine, UT Health San Antonio, 7703 Floyd Curl Drive, DTL 5.532U, San Antonio, TX, 78229, USA
| | - Scott F Jenney
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | - Jonathan W Valvano
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | - Tim B Phillips
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | - Austin B McElroy
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | | | - Aydin Zahedivash
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | - Van N Truskett
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | | | - Marc D Feldman
- Department of Medicine, UT Health San Antonio, 7703 Floyd Curl Drive, DTL 5.532U, San Antonio, TX, 78229, USA
| | | | - Thomas E Milner
- Beckman Laser Institute, The University of California Irvine, Irvine, CA, USA
- UT Austin Cockrell School of Engineering, The University of Texas, Austin, TX, USA
| | - Stephen Derdak
- School of Health Professions, UT Health San Antonio, San Antonio, TX, USA
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Zhang J, Sans M, DeHoog RJ, Garza KY, King ME, Feider CL, Bensussan A, Keating MF, Lin JQ, Povilaitis SC, Katta N, Milner TE, Yu W, Nagi C, Dhingra S, Pirko C, Brahmbhatt KA, Van Buren G, Carter S, Thompson A, Grogan RH, Suliburk J, Eberlin LS. Clinical Translation and Evaluation of a Handheld and Biocompatible Mass Spectrometry Probe for Surgical Use. Clin Chem 2021; 67:1271-1280. [PMID: 34263289 DOI: 10.1093/clinchem/hvab098] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Accepted: 05/05/2021] [Indexed: 11/13/2022]
Abstract
BACKGROUND Intraoperative tissue analysis and identification are critical to guide surgical procedures and improve patient outcomes. Here, we describe the clinical translation and evaluation of the MasSpec Pen technology for molecular analysis of in vivo and freshly excised tissues in the operating room (OR). METHODS An Orbitrap mass spectrometer equipped with a MasSpec Pen interface was installed in an OR. A "dual-path" MasSpec Pen interface was designed and programmed for the clinical studies with 2 parallel systems that facilitated the operation of the MasSpec Pen. The MasSpec Pen devices were autoclaved before each surgical procedure and were used by surgeons and surgical staff during 100 surgeries over a 12-month period. RESULTS Detection of mass spectral profiles from 715 in vivo and ex vivo analyses performed on thyroid, parathyroid, lymph node, breast, pancreatic, and bile duct tissues during parathyroidectomies, thyroidectomies, breast, and pancreatic neoplasia surgeries was achieved. The MasSpec Pen enabled gentle extraction and sensitive detection of various molecular species including small metabolites and lipids using a droplet of sterile water without causing apparent tissue damage. Notably, effective molecular analysis was achieved while no limitations to sequential histologic tissue analysis were identified and no device-related complications were reported for any of the patients. CONCLUSIONS This study shows that the MasSpec Pen system can be successfully incorporated into the OR, allowing direct detection of rich molecular profiles from tissues with a seconds-long turnaround time that could be used to inform surgical and clinical decisions without disrupting tissue analysis workflows.
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Affiliation(s)
- Jialing Zhang
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - Marta Sans
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - Rachel J DeHoog
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - Kyana Y Garza
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - Mary E King
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - Clara L Feider
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - Alena Bensussan
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - Michael F Keating
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | - John Q Lin
- Department of Chemistry, The University of Texas at Austin, Austin, TX
| | | | - Nitesh Katta
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX
| | - Thomas E Milner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX
| | - Wendong Yu
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX
| | - Chandandeep Nagi
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX
| | - Sadhna Dhingra
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX
| | | | | | | | - Stacey Carter
- Department of Surgery, Baylor College of Medicine, Houston, TX
| | | | - Raymon H Grogan
- Department of Surgery, Baylor College of Medicine, Houston, TX
| | - James Suliburk
- Department of Surgery, Baylor College of Medicine, Houston, TX
| | - Livia S Eberlin
- Department of Chemistry, The University of Texas at Austin, Austin, TX
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14
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Andleeb F, Katta N, Gruslova A, Muralidharan B, Estrada A, McElroy AB, Ullah H, Brenner AJ, Milner TE. Differentiation of Brain Tumor Microvasculature From Normal Vessels Using Optical Coherence Angiography. Lasers Surg Med 2021; 53:1386-1394. [PMID: 34130353 DOI: 10.1002/lsm.23446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 05/23/2021] [Accepted: 05/27/2021] [Indexed: 02/02/2023]
Abstract
BACKGROUND AND OBJECTIVES Despite rapid advances and discoveries in medical imaging, monitoring therapeutic efficacy for malignant gliomas and monitoring tumor vasculature remains problematic. The purpose of this study is to utilize optical coherence angiography for vasculature characterization inside and surrounding brain tumors in a murine xenograft brain tumor model. Features included in our analysis include fractional blood volume, vessel tortuosity, diameter, orientation, and directionality. STUDY DESIGN/MATERIALS AND METHODS In this study, five tumorous mice models at 4 weeks of age were imaged. Human glioblastoma cells were injected into the brain and allowed to grow for 4 weeks and then imaged using optical coherence tomography. RESULTS Results suggest that blood vessels outside the tumor contain a greater fractional blood volume as compared with vessels inside the tumor. Vessels inside the tumor are more tortuous as compared with those outside the tumor. Results indicate that vessels near the tumor margin are directed inward towards the tumor while normal vessels show a more random orientation. CONCLUSION Quantification of vascular microenvironments in brain gliomas can provide functional vascular parameters to aid various diagnostic and therapeutic studies. © 2021 Wiley Periodicals LLC.
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Affiliation(s)
- Farah Andleeb
- Department of Biomedical Engineering, The University of Texas Austin, Austin, Texas, 78712, USA.,Biophotonics Research Lab, Institute of Physics, The Islamia University, Bahawalpur, Bahawalpur, Punjab, 63100, Pakistan.,Department of Physics, Government Sadiq College Women University Bahawalpur, Bahwalpur, Punjab, 63100, Pakistan
| | - Nitesh Katta
- Department of Biomedical Engineering, The University of Texas Austin, Austin, Texas, 78712, USA
| | - Aleksandra Gruslova
- University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229, USA
| | - Bharadwaj Muralidharan
- Department of Biomedical Engineering, The University of Texas Austin, Austin, Texas, 78712, USA
| | - Arnold Estrada
- Department of Biomedical Engineering, The University of Texas Austin, Austin, Texas, 78712, USA
| | - Austin B McElroy
- Department of Biomedical Engineering, The University of Texas Austin, Austin, Texas, 78712, USA
| | - Hafeez Ullah
- Biophotonics Research Lab, Institute of Physics, The Islamia University, Bahawalpur, Bahawalpur, Punjab, 63100, Pakistan
| | - Andrew J Brenner
- University of Texas Health Science Center at San Antonio, San Antonio, Texas, 78229, USA
| | - Thomas E Milner
- Department of Biomedical Engineering, The University of Texas Austin, Austin, Texas, 78712, USA
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15
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Halaney DL, Katta N, Fallah H, Aguilar G, Milner TE. Group Refractive Index of Nanocrystalline Yttria-Stabilized Zirconia Transparent Cranial Implants. Front Bioeng Biotechnol 2021; 9:619686. [PMID: 33869149 PMCID: PMC8044953 DOI: 10.3389/fbioe.2021.619686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 03/02/2021] [Indexed: 11/18/2022] Open
Abstract
Transparent “Window to the Brain” (WttB) cranial implants made from a biocompatible ceramic, nanocrystalline Yttria-Stabilized Zirconia (nc-YSZ), were recently reported. These reports demonstrated chronic brain imaging across the implants in mice using optical coherence tomography (OCT) and laser speckle imaging. However, optical properties of these transparent cranial implants are neither completely characterized nor completely understood. In this study, we measure optical properties of the implant using a swept source OCT system with a spectral range of 136 nm centered at 1,300 nm to characterize the group refractive index of the nc-YSZ window, over a narrow range of temperatures at which the implant may be used during imaging or therapy (20–43°C). Group refractive index was found to be 2.1–2.2 for OCT imaging over this temperature range. Chromatic dispersion for this spectral range was observed to vary over the sample, sometimes flipping signs between normal and anomalous dispersion. These properties of nc-YSZ should be considered when designing optical systems and procedures that propagate light through the window, and when interpreting OCT brain images acquired across the window.
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Affiliation(s)
- David L Halaney
- Laboratory of Guillermo Aguilar, Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
| | - Nitesh Katta
- Laboratory of Thomas Milner, Department of Biomedical Engineering, University of Texas, Austin, TX, United States
| | | | - Guillermo Aguilar
- Laboratory of Guillermo Aguilar, Department of Mechanical Engineering, University of California, Riverside, Riverside, CA, United States
| | - Thomas E Milner
- Laboratory of Thomas Milner, Department of Biomedical Engineering, University of Texas, Austin, TX, United States
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16
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Nguyen HTM, Katta N, Widman JA, Takematsu E, Feng X, Torres-Hurtado SA, Betancourt T, Baker AB, Suggs LJ, Milner TE, Tunnell JW. Laser nanobubbles induce immunogenic cell death in breast cancer. Nanoscale 2021; 13:3644-3653. [PMID: 33538275 PMCID: PMC8710258 DOI: 10.1039/d0nr06587k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Recent advances in immunotherapy have highlighted a need for therapeutics that initiate immunogenic cell death in tumors to stimulate the body's immune response to cancer. This study examines whether laser-generated bubbles surrounding nanoparticles ("nanobubbles") induce an immunogenic response for cancer treatment. A single nanosecond laser pulse at 1064 nm generates micron-sized bubbles surrounding gold nanorods in the cytoplasm of breast cancer cells. Cell death occurred in cells treated with nanorods and irradiated, but not in cells with irradiation treatment alone. Cells treated with nanorods and irradiation had increased damage-associated molecular patterns (DAMPs), including increased expression of chaperone proteins human high mobility group box 1 (HMGB1), adenosine triphosphate (ATP), and heat shock protein 70 (HSP70). This enhanced expression of DAMPs led to the activation of dendritic cells. Overall, this treatment approach is a rapid and highly specific method to eradicate tumor cells with simultaneous immunogenic cell death signaling, showing potential as a combination strategy for immunotherapy.
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Affiliation(s)
- Hieu T M Nguyen
- Department of Biomedical Engineering, The University of Texas at Austin, TX, USA.
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17
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Keating MF, Zhang J, Feider CL, Retailleau S, Reid R, Antaris A, Hart B, Tan G, Milner TE, Miller K, Eberlin LS. Integrating the MasSpec Pen to the da Vinci Surgical System for In Vivo Tissue Analysis during a Robotic Assisted Porcine Surgery. Anal Chem 2020; 92:11535-11542. [PMID: 32786489 DOI: 10.1021/acs.analchem.0c02037] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Minimally invasive robotic-assisted surgeries have been increasingly used as a first-line of treatment for patients undergoing oncologic surgeries. In-situ tissue identification is critical to guide tissue resection and assist decision-making. Traditional intraoperative histopathologic analysis of frozen tissue sections can be time-consuming and present logistical challenges which interrupt surgical workflows. We report the development and implementation of a laparoscopic, drop-in version of the MasSpec Pen device integrated into the da Vinci Xi Surgical system for in vivo tissue analysis in a robotic-assisted porcine surgery. We evaluated the performance of the drop-in MasSpec Pen during surgery by introducing the device into the animal upper gastrointestinal system and performing in vivo analyses of the stomach and liver, including charred and bloody tissues after electrocauterization. The molecular profiles obtained included ions tentatively identified as metabolites and lipids typically observed with MasSpec Pen analysis, without causing observable tissue damage. Statistical classifiers built to distinguish porcine liver and stomach tissues using the in vivo data yielded an overall tissue identification accuracy of 98% (n = 53 analyses). The results provide evidence that the drop-in MasSpec Pen developed can be used to acquire mass spectra in vivo during a robotic-assisted surgery and might be used as an in vivo tissue assessment tool to help guide surgical resections and streamline surgical workflows.
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Affiliation(s)
- Michael F Keating
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78751, United States
| | - Jialing Zhang
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78751, United States
| | - Clara L Feider
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78751, United States
| | | | - Robert Reid
- Intuitive Surgical, Sunnyvale, California 94086, United States
| | | | - Bradley Hart
- Thermo Fisher Scientific, San Jose, California 95134, United States
| | - Gina Tan
- Thermo Fisher Scientific, San Jose, California 95134, United States
| | - Thomas E Milner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78751, United States
| | - Kyle Miller
- Intuitive Surgical, Sunnyvale, California 94086, United States
| | - Livia S Eberlin
- Department of Chemistry, The University of Texas at Austin, Austin, Texas 78751, United States
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18
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Gardner MR, Baruah V, Vargas G, Motamedi M, Milner TE, Rylander HG. Scattering Angle Resolved Optical Coherence Tomography Detects Early Changes in 3xTg Alzheimer's Disease Mouse Model. Transl Vis Sci Technol 2020; 9:18. [PMID: 32821490 PMCID: PMC7401921 DOI: 10.1167/tvst.9.5.18] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 03/02/2020] [Indexed: 02/07/2023] Open
Abstract
Purpose Clinical intensity-based optical coherence tomographic retinal imaging is unable to resolve some of the earliest changes to Alzheimer's disease (AD) neurons. The aim of this pilot study was to demonstrate that scattering-angle-resolved optical coherence tomography (SAR-OCT), which is sensitive to changes in light scattering angle, is a candidate retinal imaging modality for early AD detection. SAR-OCT signal data may be sensitive to changes in intracellular constituent morphology that are not detectable with conventional OCT. Methods In this cross-sectional study, retinas of a triple transgenic mouse model of AD (3xTg-AD) were imaged alongside age-matched control mice (C57BL/6J) using SAR-OCT. A total of 32 mice (12 control, 20 3xTg-Ad) at four ages (10, 20, 30, and 45 weeks) were included in this cross-sectional study, and three retinal feature sets (scattering, thickness, and angiography) were examined between the disease and control groups. Results AD mice had significantly increased scattering diversity (lower SAR-OCT C parameter) at the earliest imaging time (10 weeks). Differences in the C parameter between AD and control mice were diminished at later times when both groups showed increased scattering diversity. AD mice have reduced retinal thickness compared to controls, particularly in central regions and superficial layers. No differences in vascular density or fractional blood volume between groups were detected. Conclusions SAR-OCT is sensitive to scattering angle changes in a 3xTg-AD mouse model and could provide early-stage biomarkers for neurodegenerative diseases such as AD. Translational Relevance Clinical OCT systems may be modified to record SAR-OCT images for non-invasive retinal diagnostic imaging of patients with neurodegenerative diseases such as AD.
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Affiliation(s)
- Michael R Gardner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.,Department of Biomedical Engineering, King Faisal University, Al-Hofuf, Al-Ahsa, Saudi Arabia
| | - Vikram Baruah
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Gracie Vargas
- Center for Biomedical Engineering, The University of Texas Medical Branch, Galveston, TX, USA
| | - Massoud Motamedi
- Center for Biomedical Engineering, The University of Texas Medical Branch, Galveston, TX, USA
| | - Thomas E Milner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Henry G Rylander
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
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19
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Milner TE. Introduction to Special Issue Honoring the Contributions of AJ Welch. Lasers Surg Med 2019; 52:195. [PMID: 31803952 DOI: 10.1002/lsm.23199] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2019] [Indexed: 11/11/2022]
Affiliation(s)
- Thomas E Milner
- Biomedical Engineering Department, The University of Texas at Austin, Austin, TX, 78712
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20
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Hoyt T, Feldman MD, Okutucu S, Lendel V, Marmagkiolis K, McIntosh V, Ates I, Kose G, Mego D, Paixao A, Iliescu C, Park J, Shaar M, Avci R, McElroy A, Dijkstra J, Milner TE, Cilingiroglu M. Assessment of Vascular Patency and Inflammation with Intravascular Optical Coherence Tomography in Patients with Superficial Femoral Artery Disease Treated with Zilver PTX Stents. Cardiovasc Revasc Med 2019; 21:101-107. [PMID: 31395436 DOI: 10.1016/j.carrev.2019.07.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 06/15/2019] [Accepted: 07/02/2019] [Indexed: 10/26/2022]
Abstract
PURPOSE Zilver PTX nitinol self-expanding drug-eluting stent with paclitaxel coating is effective for treatment of superficial femoral artery (SFA) disease. However, as with any stent, it induces a measure of vascular inflammatory response. The current clinical trial (NCT02734836) aimed to assess vascular patency, remodeling, and inflammatory markers with intravascular optical coherence tomography (OCT) in patients with SFA disease treated with Zilver PTX stents. METHODS Serial OCT examinations were performed in 13 patients at baseline and 12-month follow-up. Variables evaluated included neointimal area, luminal narrowing, thrombus area, stent expansion as well as measures of inflammation including, peri-strut low-intensity area (PLIA), macrophage arc, neovascularization, stent strut apposition and coverage. RESULTS Percentage of malapposed struts decreased from 10.3 ± 7.9% post-intervention to 1.1 ± 2.2% at 12-month follow-up, but one patient showed late-acquired stent malapposition (LASM). The percent of uncovered struts at follow-up was 3.0 ± 4.5%. Average expansion of stent cross-sectional area from baseline to follow-up was 35 ± 19%. The average neointimal area was 7.8 ± 3.8 mm2. Maximal luminal narrowing was 61.1 ± 25.0%, and average luminal narrowing was 35.4 ± 18.2%. Average peri-strut low-intensity area (PLIA) per strut was 0.017 ± 0.018 mm2. Average number of neovessels per mm of stent was 0.138 ± 0.181. Average macrophage angle per frame at follow-up was 7 ± 11°. Average thrombus area at follow-up was 0.0093 ± 0.0184 mm2. CONCLUSION At 12-month follow-up, OCT analysis of Zilver PTX stent shows outward remodeling and minimal neointimal growth, but evidence of inflammation including PLIA, neovessels, thrombus and macrophages. SUMMARY Thirteen patients with PAD had paclitaxel-coated stents implanted in their SFAs and were then imaged with OCT at baseline and 12-month follow-up. OCT proxy metrics of inflammation were quantified.
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Affiliation(s)
- Taylor Hoyt
- University of Texas Health, 7703 Floyd Curl Dr., San Antonio US-TX 78229, United States of America.
| | - Marc D Feldman
- University of Texas Health, 7703 Floyd Curl Dr., San Antonio US-TX 78229, United States of America.
| | - Sercan Okutucu
- Memorial Ankara Hospital, Balgat Mah., Mevlana Blv., & 1422. Sok. No: 4, 06520 Ankara, Turkey
| | - Vasili Lendel
- Arkansas Heart Hospital, 1701 South Shackleford Rd., Little Rock US-AR 72211, United States of America.
| | - Konstantinos Marmagkiolis
- Florida Hospital Pepin Heart Institute, 3100 E Fletcher Ave., Tampa US-FL 33613, United States of America
| | - Victoria McIntosh
- Arkansas Heart Hospital, 1701 South Shackleford Rd., Little Rock US-AR 72211, United States of America.
| | - Ismail Ates
- Bahcesehir University, School of Medicine, Yıldız Mh., Çırağan Cd., 34349 Istanbul, Turkey
| | - Gulcan Kose
- Bahcesehir University, School of Medicine, Yıldız Mh., Çırağan Cd., 34349 Istanbul, Turkey
| | - David Mego
- Arkansas Heart Hospital, 1701 South Shackleford Rd., Little Rock US-AR 72211, United States of America
| | - Andre Paixao
- Arkansas Heart Hospital, 1701 South Shackleford Rd., Little Rock US-AR 72211, United States of America
| | - Cezar Iliescu
- UT Houston MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston US-TX 77030, United States of America.
| | - Jongwan Park
- University of Texas - 110 Inner Campus Dr., Austin US-TX 78705, United States of America.
| | - Mohammad Shaar
- University of Texas Health, 7703 Floyd Curl Dr., San Antonio US-TX 78229, United States of America.
| | - Recep Avci
- University of Arkansas for Medical Sciences, 4301 W Markham St., Little Rock US-AR 72205, United States of America
| | - Austin McElroy
- University of Texas - 110 Inner Campus Dr., Austin US-TX 78705, United States of America
| | - Jouke Dijkstra
- Leiden University Medical Centre - Albinusdreef 2, 2333 ZA Leiden, Netherlands.
| | - Thomas E Milner
- University of Texas - 110 Inner Campus Dr., Austin US-TX 78705, United States of America
| | - Mehmet Cilingiroglu
- Arkansas Heart Hospital, 1701 South Shackleford Rd., Little Rock US-AR 72211, United States of America; Bahcesehir University, School of Medicine, Yıldız Mh., Çırağan Cd., 34349 Istanbul, Turkey
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21
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Katta N, Estrada AD, McElroy AB, Gruslova A, Oglesby M, Cabe AG, Feldman MD, Fleming RYD, Brenner AJ, Milner TE. Laser brain cancer surgery in a xenograft model guided by optical coherence tomography. Am J Cancer Res 2019; 9:3555-3564. [PMID: 31281497 PMCID: PMC6587169 DOI: 10.7150/thno.31811] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 04/24/2019] [Indexed: 12/16/2022] Open
Abstract
Higher precision surgical devices are needed for tumor resections near critical brain structures. The goal of this study is to demonstrate feasibility of a system capable of precise and bloodless tumor ablation. An image-guided laser surgical system is presented for excision of brain tumors in vivo in a murine xenograft model. The system combines optical coherence tomography (OCT) guidance with surgical lasers for high-precision tumor ablation (Er:YAG) and microcirculation coagulation (Thulium (Tm) fiber laser). Methods: A fluorescent human glioblastoma cell line was injected into mice and allowed to grow four weeks. Craniotomies were performed and tumors were imaged with confocal fluorescence microscopy. The mice were subsequently OCT imaged prior, during and after laser coagulation and/or ablation. The prior OCT images were used to compute three-dimensional tumor margin and angiography images, which guided the coagulation and ablation steps. Histology of the treated regions was then compared to post-treatment OCT images. Results: Tumor sizing based on OCT margin detection matched histology to within experimental error. Although fluorescence microscopy imaging showed the tumors were collocated with OCT imaging, margin assessment using confocal microscopy failed to see the extent of the tumor beyond ~ 250 µm in depth, as verified by OCT and histology. The two-laser approach to surgery utilizing Tm wavelength for coagulation and Er:YAG for ablation yielded bloodless resection of tumor regions with minimal residual damage as seen in histology. Conclusion: Precise and bloodless tumor resection under OCT image guidance is demonstrated in the murine xenograft brain cancer model. Tumor margins and vasculature are accurately made visible without need for exogenous contrast agents.
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22
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Gardner MR, Rahman AS, Milner TE, Rylander HG. Scattering-Angle-Resolved Optical Coherence Tomography of a Hypoxic Mouse Retina Model. J Exp Neurosci 2019; 13:1179069519837564. [PMID: 30944521 PMCID: PMC6440039 DOI: 10.1177/1179069519837564] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 02/21/2019] [Indexed: 12/27/2022] Open
Abstract
Several studies have noted a correlation between retinal degeneration and traumatic encephalopathy (TE) making the retina a leading candidate for detection and assessment. Scattering-angle-resolved optical coherence tomography (SAR-OCT) is a candidate imaging modality to detect sub-resolution changes in retinal microstructure. SAR-OCT images of murine retinas that experience a hypoxic insult—euthanasia by isoflurane overdose—are presented. A total of 4 SAR-OCT measurement parameters are reported in 6 longitudinal experiments: blood flow volume fraction, total retinal thickness, reflectance index, and scattering angle. As each mouse expires, blood flow volume fraction decreases, total retinal thickness increases, reflectance index decreases, and scattering angle diversity increases. Contribution of the retinal vasculature to scattering angle diversity is discussed. Results of this study suggest the utility of SAR-OCT to measure TE using scattering angle diversity contrast in the retina.
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Affiliation(s)
- Michael R Gardner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA.,Department of Chemical Engineering, University of Bahrain, Isa Town, Bahrain
| | - Ayesha S Rahman
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Thomas E Milner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
| | - Henry G Rylander
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX, USA
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23
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Hashemi M, Muralidharan B, Omidi M, Mohammadi J, Sefidbakht Y, Kima ES, Smyth HDC, Shalbaf M, Milner TE. Effect of size and chemical composition of graphene oxide nanoparticles on optical absorption cross-section. J Biomed Opt 2018; 23:1-9. [PMID: 30156063 DOI: 10.1117/1.jbo.23.8.085007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Accepted: 08/03/2018] [Indexed: 06/08/2023]
Abstract
Photothermal therapy with various nanoparticles, as photothermal transducers, is a widely researched technique. A continuous wave (CW) laser is employed during this procedure. The therapeutic setup is slightly modified to measure the optical absorption cross-section of the graphene oxide (GO), by mitigating the effects of heat diffusion and light scattering. With an 808-nm CW laser setup modulated by a waveform modulation setup, the effect of nanoparticle size and composition of GO in water on optical absorption cross section is characterized.
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Affiliation(s)
- Mohadeseh Hashemi
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
- University of Tehran, Faculty of new Science and Engineering, Tehran, Iran
- University of Texas at Austin, Division of Pharmaceutics, College of Pharmacy, Austin, Texas, United States
| | - Bharadwaj Muralidharan
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
- University of Texas at Austin, Department of Electrical and Computer Engineering, Austin, Texas, United States
| | - Meisam Omidi
- Shahid Beheshti University, G.C., Protein Research Center, Tehran, Iran
| | - Javad Mohammadi
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
- University of Tehran, Faculty of new Science and Engineering, Tehran, Iran
| | - Yahya Sefidbakht
- Shahid Beheshti University, G.C., Protein Research Center, Tehran, Iran
| | - Eun Song Kima
- University of Texas at Austin, Division of Pharmaceutics, College of Pharmacy, Austin, Texas, United States
| | - Hugh D C Smyth
- University of Texas at Austin, Division of Pharmaceutics, College of Pharmacy, Austin, Texas, United States
| | - Mohammad Shalbaf
- Shahid Beheshti University, G.C., Protein Research Center, Tehran, Iran
| | - Thomas E Milner
- University of Texas at Austin, Department of Biomedical Engineering, Austin, Texas, United States
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Zhang J, Rector J, Lin JQ, Young JH, Sans M, Katta N, Giese N, Yu W, Nagi C, Suliburk J, Liu J, Bensussan A, DeHoog RJ, Garza KY, Ludolph B, Sorace AG, Syed A, Zahedivash A, Milner TE, Eberlin LS. Nondestructive tissue analysis for ex vivo and in vivo cancer diagnosis using a handheld mass spectrometry system. Sci Transl Med 2018; 9:9/406/eaan3968. [PMID: 28878011 DOI: 10.1126/scitranslmed.aan3968] [Citation(s) in RCA: 234] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 08/17/2017] [Indexed: 12/13/2022]
Abstract
Conventional methods for histopathologic tissue diagnosis are labor- and time-intensive and can delay decision-making during diagnostic and therapeutic procedures. We report the development of an automated and biocompatible handheld mass spectrometry device for rapid and nondestructive diagnosis of human cancer tissues. The device, named MasSpec Pen, enables controlled and automated delivery of a discrete water droplet to a tissue surface for efficient extraction of biomolecules. We used the MasSpec Pen for ex vivo molecular analysis of 20 human cancer thin tissue sections and 253 human patient tissue samples including normal and cancerous tissues from breast, lung, thyroid, and ovary. The mass spectra obtained presented rich molecular profiles characterized by a variety of potential cancer biomarkers identified as metabolites, lipids, and proteins. Statistical classifiers built from the histologically validated molecular database allowed cancer prediction with high sensitivity (96.4%), specificity (96.2%), and overall accuracy (96.3%), as well as prediction of benign and malignant thyroid tumors and different histologic subtypes of lung cancer. Notably, our classifier allowed accurate diagnosis of cancer in marginal tumor regions presenting mixed histologic composition. Last, we demonstrate that the MasSpec Pen is suited for in vivo cancer diagnosis during surgery performed in tumor-bearing mouse models, without causing any observable tissue harm or stress to the animal. Our results provide evidence that the MasSpec Pen could potentially be used as a clinical and intraoperative technology for ex vivo and in vivo cancer diagnosis.
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Affiliation(s)
- Jialing Zhang
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - John Rector
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.,Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - John Q Lin
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Jonathan H Young
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Marta Sans
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Nitesh Katta
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Noah Giese
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Wendong Yu
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Chandandeep Nagi
- Department of Pathology and Immunology, Baylor College of Medicine, Houston, TX 77030, USA
| | - James Suliburk
- Department of Surgery, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jinsong Liu
- Department of Pathology, University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Alena Bensussan
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Rachel J DeHoog
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Kyana Y Garza
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Benjamin Ludolph
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA
| | - Anna G Sorace
- Department of Internal Medicine, Dell Medical School, University of Texas at Austin, Austin, TX 78712, USA
| | - Anum Syed
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Aydin Zahedivash
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Thomas E Milner
- Department of Biomedical Engineering, University of Texas at Austin, Austin, TX 78712, USA
| | - Livia S Eberlin
- Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
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Gardner MR, Lewis A, Park J, McElroy AB, Estrada AD, Fish S, Beaman JJ, Milner TE. In situ process monitoring in selective laser sintering using optical coherence tomography. Opt Eng 2018; 57:041407. [PMID: 29576665 PMCID: PMC5859933 DOI: 10.1117/1.oe.57.4.041407] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Selective laser sintering (SLS) is an efficient process in additive manufacturing that enables rapid part production from computer-based designs. However, SLS is limited by its notable lack of in-situ process monitoring when compared to other manufacturing processes. We report the incorporation of optical coherence tomography into an SLS system in detail and demonstrate access to surface and sub-surface features. Video frame rate cross-sectional imaging reveals areas of sintering uniformity and areas of excessive heat error with high temporal resolution. We propose a set of image processing techniques for SLS process monitoring with OCT and report the limitations and obstacles for further OCT integration with SLS systems.
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Affiliation(s)
- Michael R. Gardner
- The University of Texas at Austin, Department of Biomedical
Engineering, 107 W Dean Keeton St, Austin, TX, USA, 78712 Code
| | - Adam Lewis
- The University of Texas at Austin, McKetta Department of Chemical
Engineering, 200 E Dean Keeton St, Austin, TX, USA, 78712
| | - Jongwan Park
- The University of Texas at Austin, Department of Biomedical
Engineering, 107 W Dean Keeton St, Austin, TX, USA, 78712 Code
| | - Austin B. McElroy
- The University of Texas at Austin, Department of Biomedical
Engineering, 107 W Dean Keeton St, Austin, TX, USA, 78712 Code
| | - Arnold D. Estrada
- The University of Texas at Austin, Department of Biomedical
Engineering, 107 W Dean Keeton St, Austin, TX, USA, 78712 Code
| | - Scott Fish
- The University of Texas at Austin, Department of Mechanical
Engineering, 204 E Dean Keeton St, Austin, TX, USA, 78712
| | - Joseph J. Beaman
- The University of Texas at Austin, Department of Mechanical
Engineering, 204 E Dean Keeton St, Austin, TX, USA, 78712
| | - Thomas E. Milner
- The University of Texas at Austin, Department of Biomedical
Engineering, 107 W Dean Keeton St, Austin, TX, USA, 78712 Code
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Hashemi M, Omidi M, Muralidharan B, Tayebi L, Herpin MJ, Mohagheghi MA, Mohammadi J, Smyth HD, Milner TE. Layer-by-layer assembly of graphene oxide on thermosensitive liposomes for photo-chemotherapy. Acta Biomater 2018; 65:376-392. [PMID: 29109030 DOI: 10.1016/j.actbio.2017.10.040] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Revised: 10/25/2017] [Accepted: 10/27/2017] [Indexed: 01/07/2023]
Abstract
Stimuli responsive polyelectrolyte nanoparticles have been developed for chemo-photothermal destruction of breast cancer cells. This novel system, called layer by layer Lipo-graph (LBL Lipo-graph), is composed of alternate layers of graphene oxide (GO) and graphene oxide conjugated poly (l-lysine) (GO-PLL) deposited on cationic liposomes encapsulating doxorubicin. Various concentrations of GO and GO-PLL were examined and the optimal LBL Lipo-graph was found to have a particle size of 267.9 ± 13 nm, zeta potential of +43.9 ± 6.9 mV and encapsulation efficiency of 86.4 ± 4.7%. The morphology of LBL Lipo-graph was examined by cryogenic-transmission electron microscopy (Cryo-TEM), atomic force microcopy (AFM) and scanning electron microscopy (SEM). The buildup of LBL Lipo-graph was confirmed via ultraviolet-visible (UV-Vis) spectrophotometry, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. Infra-red (IR) response suggests that four layers are sufficient to induce a gel-to-liquid phase transition in response to near infra-red (NIR) laser irradiation. Light-matter interaction of LBL Lipo-graph was studied by calculating the absorption cross section in the frequency domain by utilizing Fourier analysis. Drug release assay indicates that the LBL Lipo-graph releases much faster in an acidic environment than a liposome control. A cytotoxicity assay was conducted to prove the efficacy of LBL Lipo-graph to destroy MD-MB-231 cells in response to NIR laser emission. Also, image stream flow cytometry and two photon microcopy provide supportive data for the potential application of LBL Lipo-graph for photothermal therapy. Study results suggest the novel dual-sensitive nanoparticles allow intracellular doxorubin delivery and respond to either acidic environments or NIR excitation. STATEMENT OF SIGNIFICANCE Stimuli sensitive hybrid nanoparticles have been synthesized using a layer-by-layer technique and demonstrated for dual chemo-photothermal destruction of breast cancer cells. The hybrid nanoparticles are composed of alternating layers of graphene oxide and graphene oxide conjugated poly-l-lysine coating the surface of a thermosensitive cationic liposome containing doxorubicin as a core. Data suggests that the hybrid nanoparticles may offer many advantages for chemo-photothermal therapy. Advantages include a decrease of the initial burst release which may result in the reduction in systemic toxicity, increase in pH responsivity around the tumor environment and improved NIR light absorption.
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Phipps JE, Hoyt T, Vela D, Wang T, Michalek JE, Buja LM, Jang IK, Milner TE, Feldman MD. Diagnosis of Thin-Capped Fibroatheromas in Intravascular Optical Coherence Tomography Images: Effects of Light Scattering. Circ Cardiovasc Interv 2017; 9:CIRCINTERVENTIONS.115.003163. [PMID: 27406987 DOI: 10.1161/circinterventions.115.003163] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 05/16/2016] [Indexed: 12/12/2022]
Abstract
BACKGROUND Intravascular optical coherence tomography (IVOCT) images are recorded by detecting light backscattered within coronary arteries. We hypothesize that non-thin-capped fibroatheroma (TCFA) causes may scatter light to create the false appearance of IVOCT TCFA. METHODS AND RESULTS Ten human cadaver hearts were imaged with IVOCT (n=14 coronary arteries). IVOCT and histological TCFA images were coregistered and compared. Of 21 IVOCT TCFAs (fibrous cap <65 μm, lipid arc >1 quadrant), only 8 were true histological TCFA. Foam cell infiltration was responsible for 70% of false IVOCT TCFA and caused both thick-capped fibroatheromas to appear as TCFA, and the appearance of TCFAs when no lipid core was present. Other false IVOCT TCFA causes included smooth muscle cell-rich fibrous tissue (12%) and loose connective tissue (9%). If the lipid arc >1 quadrant (obtuse) criterion was disregarded, 45 IVOCT TCFAs were identified, and sensitivity of IVOCT TCFA detection increased from 63% to 87%, and specificity remained high at 92%. CONCLUSIONS We demonstrate that IVOCT can exhibit 87% (95% CI, 75%-93%) sensitivity and 92% specificity (95% CI, 86%-96%) to detect all lipid arcs (both obtuse and acute, <1 quadrant) TCFA, and we also propose new mechanisms involving light scattering that explain why other plaque components can masquerade as TCFA and cause low positive predictive value of IVOCT for TCFA detection (47% for obtuse lipid arcs). Disregarding the lipid arc >1 quadrant requirement enhances the ability of IVOCT to detect TCFA.
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Affiliation(s)
- Jennifer E Phipps
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - Taylor Hoyt
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - Deborah Vela
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - Tianyi Wang
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - Joel E Michalek
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - L Maximilian Buja
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - Ik-Kyung Jang
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - Thomas E Milner
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.)
| | - Marc D Feldman
- From the Department of Medicine (J.E.P., T.H., M.D.F.) and Epidemiology and Biostatistics (J.E.M.), University of Texas Health Science Center San Antonio; Department of Cardiovascular Pathology, Texas Heart Institute, Houston (D.V., L.M.B.); Department of Biomedical Engineering, University of Texas at Austin (T.W., T.E.M.); Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston (I.-K.J.); and Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio (M.D.F.).
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Hashemi M, Omidi M, Muralidharan B, Smyth H, Mohagheghi MA, Mohammadi J, Milner TE. Correction to "Evaluation of the Photothermal Properties of a Reduced Graphene Oxide/Arginine Nanostructure for Near-Infrared Absorption". ACS Appl Mater Interfaces 2017; 9:39872. [PMID: 29099170 DOI: 10.1021/acsami.7b15455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
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Hashemi M, Omidi M, Muralidharan B, Smyth H, Mohagheghi MA, Mohammadi J, Milner TE. Evaluation of the Photothermal Properties of a Reduced Graphene Oxide/Arginine Nanostructure for Near-Infrared Absorption. ACS Appl Mater Interfaces 2017; 9:32607-32620. [PMID: 28841283 DOI: 10.1021/acsami.7b11291] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Strong near-infrared (NIR) absorption of reduced graphene oxide (rGO) make this material a candidate for photothermal therapy. The use of rGO has been limited by low stability in aqueous media due to the lack of surface hydrophilic groups. We report synthesis of a novel form of reduced graphene-arginine (rGO-Arg) as a nanoprobe. Introduction of Arg to the surface of rGO not only increases the stability in aqueous solutions but also increases cancer cell uptake. Atomic force microscopy (AFM) and transmission electron microscopy (TEM) images are recorded to characterize the morphology of rGO-Arg. Fourier transform infrared (FTIR), X-ray photoelectron spectra (XPS), Raman, and UV-vis spectroscopy are utilized to analyze the physiochemical properties of rGO-Arg. Interaction of rGO-Arg with 808 nm laser light has been evaluated by measuring the absorption cross section in response to periodically modulated intensity to minimize artifacts arising from lateral thermal diffusion with a material scattering matched to a low scattering optical standard. Cell toxicity and cellular uptake by MD-MB-231 cell lines provide supporting data for the potential application of rGO-Arg for photothermal therapy. Absorption cross-section results suggest rGO-Arg is an excellent NIR absorber that is 3.2 times stronger in comparison to GO.
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Affiliation(s)
- Mohadeseh Hashemi
- Biomedical Engineering Department, Faculty of New Sciences and Technologies, The University of Tehran , Tehran 14395-1561, Iran
- Biomedical Engineering Department, The University of Texas at Austin , Austin, Texas 78712, United States
- Division of Pharmaceutics, College of Pharmacy, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Meisam Omidi
- Protein Research Centre, Shahid Beheshti University , GC, Velenjak, Tehran 1985717443, Iran
| | - Bharadwaj Muralidharan
- Biomedical Engineering Department, The University of Texas at Austin , Austin, Texas 78712, United States
- Department of Electrical and Computer Engineering, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Hugh Smyth
- Division of Pharmaceutics, College of Pharmacy, The University of Texas at Austin , Austin, Texas 78712, United States
| | - Mohammad A Mohagheghi
- Cancer Research Center, Cancer Institute of Iran, Tehran University of Medical Sciences , Tehran 1419733141, Iran
| | - Javad Mohammadi
- Biomedical Engineering Department, Faculty of New Sciences and Technologies, The University of Tehran , Tehran 14395-1561, Iran
| | - Thomas E Milner
- Biomedical Engineering Department, The University of Texas at Austin , Austin, Texas 78712, United States
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Katta N, McElroy AB, Estrada AD, Milner TE. Optical coherence tomography image-guided smart laser knife for surgery. Lasers Surg Med 2017; 50:202-212. [PMID: 28782115 DOI: 10.1002/lsm.22705] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2017] [Indexed: 01/24/2023]
Abstract
BACKGROUND AND OBJECTIVE Surgical oncology can benefit from specialized tools that enhance imaging and enable precise cutting and removal of tissue without damage to adjacent structures. The combination of high-resolution, fast optical coherence tomography (OCT) co-aligned with a nanosecond pulsed thulium (Tm) laser offers advantages over conventional surgical laser systems. Tm lasers provide superior beam quality, high volumetric tissue removal rates with minimal residual thermal footprint in tissue, enabling a reduction in unwanted damage to delicate adjacent sub-surface structures such as nerves or micro-vessels. We investigated such a combined Tm/OCT system with co-aligned imaging and cutting beams-a configuration we call a "smart laser knife." METHODS A blow-off model that considers absorption coefficients and beam delivery systems was utilized to predict Tm cut depth, tissue removal rate and spatial distribution of residual thermal injury. Experiments were performed to verify the volumetric removal rate predicted by the model as a function of average power. A bench-top, combined Tm/OCT system was constructed using a 15W 1940 nm nanosecond pulsed Tm fiber laser (500 μJ pulse energy, 100 ns pulse duration, 30 kHz repetition rate) for removing tissue and a swept source laser (1310 ± 70 nm, 100 kHz sweep rate) for OCT imaging. Tissue phantoms were used to demonstrate precise surgery with blood vessel avoidance. Depth imaging informed cutting/removal of targeted tissue structures by the Tm laser was performed. RESULTS Laser cutting was accomplished around and above phantom blood vessels while avoiding damage to vessel walls. A tissue removal rate of 5.5 mm3 /sec was achieved experimentally, in comparison to the model prediction of approximately 6 mm3 /sec. CONCLUSION We describe a system that combines OCT and laser tissue modification with a Tm laser. Simulation results of the tissue removal rate using a simple model, as a function of average power, are in good agreement with experimental results using tissue phantoms. Lasers Surg. Med. 50:202-212, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Nitesh Katta
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas
| | - Austin B McElroy
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - Arnold D Estrada
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
| | - Thomas E Milner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas
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Milner TE. Lars O. Svaasand. Lasers Surg Med 2017; 49:334. [PMID: 28411386 DOI: 10.1002/lsm.22663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Affiliation(s)
- Thomas E Milner
- University of Texas at Austin, Biomedical Engineering, 1 University Station, Austin, Texas, 78712
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Minami Y, Hoyt T, Phipps JE, Milner TE, Xing L, Lee H, Yu B, Feldman MD, Jang IK. Lipid-lowering therapy stabilizes the complexity of non-culprit plaques in human coronary artery: a quantitative assessment using OCT bright spot algorithm. Int J Cardiovasc Imaging 2016; 33:453-461. [DOI: 10.1007/s10554-016-1037-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Accepted: 12/07/2016] [Indexed: 01/16/2023]
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Yin B, Dwelle J, Wang B, Wang T, Feldman MD, Rylander HG, Milner TE. Fourier optics analysis of phase-mask-based path-length-multiplexed optical coherence tomography. J Opt Soc Am A Opt Image Sci Vis 2015; 32:2169-77. [PMID: 26560931 DOI: 10.1364/josaa.32.002169] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Optical coherence tomography (OCT) is an imaging technique that constructs a depth-resolved image by measuring the optical path-length difference between broadband light backscattered from a sample and a reference surface. For many OCT sample arm optical configurations, sample illumination and backscattered light detection share a common path. When a phase mask is placed in the sample path, features in the detected signal are observed, which suggests that an analysis of a generic common path OCT imaging system is warranted. In this study, we present a Fourier optics analysis using a Fresnel diffraction approximation of an OCT system with a path-length-multiplexing element (PME) inserted in the sample arm optics. The analysis may be generalized for most phase-mask-based OCT systems. A radial-angle-diverse PME is analyzed in detail, and the point spread function, coherent transfer function, sensitivity of backscattering angular diversity detection, and signal formation in terms of sample spatial frequency are simulated and discussed. The analysis reveals important imaging features and application limitations of OCT imaging systems with a phase mask in the sample path optics.
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Halaney DL, Zahedivash A, Phipps JE, Wang T, Dwelle J, Saux CJL, Asmis R, Milner TE, Feldman MD. Differences in forward angular light scattering distributions between M1 and M2 macrophages. J Biomed Opt 2015; 20:115002. [PMID: 26538329 PMCID: PMC4881287 DOI: 10.1117/1.jbo.20.11.115002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 10/09/2015] [Indexed: 05/11/2023]
Abstract
The ability to distinguish macrophage subtypes noninvasively could have diagnostic potential in cancer, atherosclerosis, and diabetes, where polarized M1 and M2 macrophages play critical and often opposing roles. Current methods to distinguish macrophage subtypes rely on tissue biopsy. Optical imaging techniques based on light scattering are of interest as they can be translated into biopsy-free strategies. Because mitochondria are relatively strong subcellular light scattering centers, and M2 macrophages are known to have enhanced mitochondrial biogenesis compared to M1, we hypothesized that M1 and M2 macrophages may have different angular light scattering profiles. To test this, we developed an in vitro angle-resolved forward light scattering measurement system. We found that M1 and M2 macrophage monolayers scatter relatively unequal amounts of light in the forward direction between 1.6 deg and 3.2 deg with M2 forward scattering significantly more light than M1 at increasing angles. The ratio of forward scattering can be used to identify the polarization state of macrophage populations in culture.
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Affiliation(s)
- David L. Halaney
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
- South Texas Veterans Health Care System, Department of Veterans Affairs, 7400 Merton Minter, San Antonio, Texas 78229, United States
| | - Aydin Zahedivash
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Jennifer E. Phipps
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Tianyi Wang
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Jordan Dwelle
- South Texas Veterans Health Care System, Department of Veterans Affairs, 7400 Merton Minter, San Antonio, Texas 78229, United States
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Claude Jourdan Le Saux
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Reto Asmis
- University of Texas Health Science Center at San Antonio, Departments of Clinical Laboratory Sciences and Biochemistry, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Thomas E. Milner
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Marc D. Feldman
- University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
- South Texas Veterans Health Care System, Department of Veterans Affairs, 7400 Merton Minter, San Antonio, Texas 78229, United States
- Address all correspondence to: Marc D. Feldman, E-mail:
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Wang T, McElroy A, Halaney D, Vela D, Fung E, Hossain S, Phipps J, Wang B, Yin B, Feldman MD, Milner TE. Detection of plaque structure and composition using OCT combined with two-photon luminescence (TPL) imaging. Lasers Surg Med 2015; 47:485-94. [PMID: 26018531 DOI: 10.1002/lsm.22366] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/05/2015] [Indexed: 12/11/2022]
Abstract
BACKGROUND AND OBJECTIVES Atherosclerosis and plaque rupture leads to myocardial infarction and stroke. A novel hybrid optical coherence tomography (OCT) and two-photon luminescence (TPL) fiber-based imaging system was developed to characterize tissue constituents in the context of plaque morphology. STUDY DESIGN/MATERIALS AND METHODS Ex vivo coronary arteries (34 regions of interest) from three human hearts with atherosclerotic plaques were examined by OCT-TPL imaging. Histological sections (4 μm in thickness) were stained with Oil Red O for lipid, Von Kossa for calcium, and Verhoeff-Masson Tri-Elastic for collagen/elastin fibers and compared with imaging results. RESULTS Biochemical components in plaques including lipid, oxidized-LDL, and calcium, as well as a non-tissue component (metal) are distinguished by multi-channel TPL images with statistical significance (P < 0.001). TPL imaging provides complementary optical contrast to OCT (two-photon absorption/emission vs scattering). Merged OCT-TPL images demonstrate the distribution of lipid deposits in registration with detailed plaque surface profile. CONCLUSIONS Results suggest that multi-channel TPL imaging can effectively identify lipid sub-types and different plaque components. Furthermore, fiber-based hybrid OCT-TPL imaging simultaneously detects plaque structure and composition, improving the efficacy of vulnerable plaque detection and characterization.
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Affiliation(s)
- Tianyi Wang
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas
| | - Austin McElroy
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas
| | - David Halaney
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas.,South Texas Veterans Health Care System, San Antonio, Texas
| | | | - Edmund Fung
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas
| | - Shafat Hossain
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas
| | - Jennifer Phipps
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas
| | - Bingqing Wang
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas
| | - Biwei Yin
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas
| | - Marc D Feldman
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas.,South Texas Veterans Health Care System, San Antonio, Texas
| | - Thomas E Milner
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas
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Wang T, McElroy A, Halaney D, Vela D, Fung E, Hossain S, Phipps J, Wang B, Yin B, Feldman MD, Milner TE. Dual-modality fiber-based OCT-TPL imaging system for simultaneous microstructural and molecular analysis of atherosclerotic plaques. Biomed Opt Express 2015; 6:1665-78. [PMID: 26137371 PMCID: PMC4467709 DOI: 10.1364/boe.6.001665] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 02/17/2015] [Accepted: 02/17/2015] [Indexed: 05/25/2023]
Abstract
New optical imaging techniques that provide contrast to study both the anatomy and composition of atherosclerotic plaques can be utilized to better understand the formation, progression and clinical complications of human coronary artery disease. We present a dual-modality fiber-based optical imaging system for simultaneous microstructural and molecular analysis of atherosclerotic plaques that combines optical coherence tomography (OCT) and two-photon luminescence (TPL) imaging. Experimental results from ex vivo human coronary arteries show that OCT and TPL optical contrast in recorded OCT-TPL images is complimentary and in agreement with histological analysis. Molecular composition (e.g., lipid and oxidized-LDL) detected by TPL imaging can be overlaid onto plaque microstructure depicted by OCT, providing new opportunities for atherosclerotic plaque identification and characterization.
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Affiliation(s)
- Tianyi Wang
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - Austin McElroy
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - David Halaney
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA ; South Texas Veterans Health Care System, San Antonio, Texas 78229, USA
| | - Deborah Vela
- Texas Heart Institute, Houston, Texas 77030, USA
| | - Edmund Fung
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - Shafat Hossain
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - Jennifer Phipps
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA
| | - Bingqing Wang
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - Biwei Yin
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - Marc D Feldman
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA ; South Texas Veterans Health Care System, San Antonio, Texas 78229, USA
| | - Thomas E Milner
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
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Liu S, Datta A, Ho D, Dwelle J, Wang D, Milner TE, Rylander HG, Markey MK. Effect of image registration on longitudinal analysis of retinal nerve fiber layer thickness of non-human primates using Optical Coherence Tomography (OCT). Eye Vis (Lond) 2015; 2:3. [PMID: 26605359 PMCID: PMC4657366 DOI: 10.1186/s40662-015-0013-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/13/2014] [Accepted: 01/27/2015] [Indexed: 11/18/2022]
Abstract
BACKGROUND In this paper we determined the benefits of image registration on estimating longitudinal retinal nerve fiber layer thickness (RNFLT) changes. METHODS RNFLT maps around the optic nerve head (ONH) of healthy primate eyes were measured using Optical Coherence Tomography (OCT) weekly for 30 weeks. One automatic algorithm based on mutual information (MI) and the other semi-automatic algorithm based on log-polar transform cross-correlation using manually segmented blood vessels (LPCC_MSBV), were used to register retinal maps longitudinally. We compared the precision and recall between manually segmented image pairs for the two algorithms using a linear mixed effects model. RESULTS We found that the precision calculated between manually segmented image pairs following registration by LPCC_MSBV algorithm is significantly better than the one following registration by MI algorithm (p < <0.0001). Trend of the all-rings and temporal, superior, nasal and inferior (TSNI) quadrants average of RNFLT over time in healthy primate eyes are not affected by registration. RNFLT of clock hours 1, 2, and 10 showed significant change over 30 weeks (p = 0.0058, 0.0054, and 0.0298 for clock hours 1, 2 and 10 respectively) without registration, but stayed constant over time with registration. CONCLUSIONS The LPCC_MSBV provides better registration of RNFLT maps recorded on different dates than the automatic MI algorithm. Registration of RNFLT maps can improve clinical analysis of glaucoma progression.
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Affiliation(s)
- Shuang Liu
- />Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712 USA
- />Present address: Clinical Neuroscience Imaging Center (CNIC), Department of Neurology, Yale School of Medicine, New Haven, CT 06510 USA
| | - Anjali Datta
- />Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78712 USA
| | - Derek Ho
- />Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712 USA
| | - Jordan Dwelle
- />Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712 USA
| | - Daifeng Wang
- />Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, TX 78712 USA
| | - Thomas E Milner
- />Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712 USA
| | - Henry Grady Rylander
- />Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712 USA
| | - Mia K Markey
- />Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712 USA
- />Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA
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Borwankar AU, Willsey BW, Twu A, Hung JJ, Stover RJ, Wang TW, Feldman MD, Milner TE, Truskett TM, Johnston KP. Gold nanoparticles with high densities of small protuberances on nanocluster cores with strong NIR extinction. RSC Adv 2015. [DOI: 10.1039/c5ra21712a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Plasmonic nanoparticles with sizes well below 100 nm and high near infrared (NIR) extinction are of great interest in biomedical imaging.
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Affiliation(s)
- Ameya U. Borwankar
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- USA
| | - Brian W. Willsey
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- USA
| | - April Twu
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- USA
| | - Jessica J. Hung
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- USA
| | - Robert J. Stover
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- USA
| | - Tianyi W. Wang
- Department of Biomedical Engineering
- The University of Texas at Austin
- USA
| | - Marc D. Feldman
- South Texas Veterans Health Care System
- San Antonio
- USA
- Division of Cardiology
- Department of Medicine
| | - Thomas E. Milner
- Department of Biomedical Engineering
- The University of Texas at Austin
- USA
| | - Thomas M. Truskett
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- USA
| | - Keith P. Johnston
- McKetta Department of Chemical Engineering
- The University of Texas at Austin
- USA
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Mancuso JJ, Halaney DL, Elahi S, Ho D, Wang T, Ouyang Y, Dijkstra J, Milner TE, Feldman MD. Intravascular optical coherence tomography light scattering artifacts: merry-go-rounding, blooming, and ghost struts. J Biomed Opt 2014; 19:126017. [PMID: 25545341 PMCID: PMC4659478 DOI: 10.1117/1.jbo.19.12.126017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2014] [Accepted: 12/04/2014] [Indexed: 06/04/2023]
Abstract
We sought to elucidate the mechanisms underlying two common intravascular optical coherence tomography (IV-OCT) artifacts that occur when imaging metallic stents: “merry-go-rounding” (MGR), which is an increase in strut arc length (SAL), and “blooming,” which is an increase in the strut reflection thickness (blooming thickness). Due to uncontrollable variables that occur in vivo, we performed an in vitro assessment of MGR and blooming in stented vessel phantoms. Using Xience V and Driver stents, we examined the effects of catheter offset, intimal strut coverage, and residual blood on SAL and blooming thickness in IV-OCT images. Catheter offset and strut coverage both caused minor MGR, while the greatest MGR effect resulted from light scattering by residual blood in the vessel lumen, with 1% hematocrit (Hct) causing a more than fourfold increase in SAL compared with saline (p<0.001 ). Residual blood also resulted in blooming, with blooming thickness more than doubling when imaged in 0.5% Hct compared with saline (p<0.001 ). We demonstrate that a previously undescribed mechanism, light scattering by residual blood in the imaging field, is the predominant cause of MGR. Light scattering also results in blooming, and a newly described artifact, three-dimensional-MGR, which results in “ghost struts” in B-scans.
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Affiliation(s)
- J. Jacob Mancuso
- The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
- South Texas Veterans Health Care System, The Department of Veterans Affairs, San Antonio, Texas 78229, United States
| | - David L. Halaney
- The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
- South Texas Veterans Health Care System, The Department of Veterans Affairs, San Antonio, Texas 78229, United States
| | - Sahar Elahi
- The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Derek Ho
- The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Tianyi Wang
- The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Yongjian Ouyang
- The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
| | - Jouke Dijkstra
- Leiden University Medical Center, Division of Image Processing, Department of Radiology, Albinusdreef 2, 2333 ZA Leiden, The Netherlands
| | - Thomas E. Milner
- The University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712, United States
| | - Marc D. Feldman
- The University of Texas Health Science Center at San Antonio, Division of Cardiology, Department of Medicine, 7703 Floyd Curl Drive, San Antonio, Texas 78229, United States
- South Texas Veterans Health Care System, The Department of Veterans Affairs, San Antonio, Texas 78229, United States
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Elahi S, Ho D, Feldman MD, Dijkstra J, Milner TE. Evaluation of IVOCT imaging of coronary artery metallic stents with neointimal coverage. Int J Cardiovasc Imaging 2014; 31:463-70. [PMID: 25395364 PMCID: PMC4368839 DOI: 10.1007/s10554-014-0569-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 11/08/2014] [Indexed: 11/26/2022]
Abstract
Accuracy of IVOCT for measurement of neointimal thickness and effect of neointima in the appearance of metallic struts in IVOCT images was investigated. Phantom vessels were constructed and coronary stents were deployed and covered with thick (250–400 μm) and thin (30–70 μm) phantom neointima. High resolution Micro-CT images of the stent struts were recorded as a gold standard. IVOCT images of the phantom vessels were acquired with various luminal blood scattering strengths and measured neointimal thicknesses from IVOCT and Micro-CT images were compared. In transparent lumen, comparison of IVOCT and Micro-CT neointima thickness measurements found no significant difference (p > 0.05) in the thick neointima phantom but a significant difference (p < 0.05) in the thin neointima phantom. For both thick and thin neointima, IVOCT neointimal thickness measurements varied from Micro-CT values by as much as ±35 %. Increased luminal scattering due to presence of blood at concentrations <5 % did not interfere with measurement of thin neointimas and was validated by ANOVA analysis (p = 0.95). IV-OCT measurement of strut feature size with an overlying thin neointima match true values determined with Micro-CT (p = 0.82). Presence of a thick neointima resulted in lateral elongation or merry-go-rounding of stent strut features in IVOCT images. Phantom IVOCT images suggest that thick neointimal layers can result in more than 40 % lateral elongation of stent strut features. Simulated IVOCT images of metallic stent struts with varying neointimal thickness suggest that neointimal light scattering can introduce the merry-go-round effect.
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Affiliation(s)
- Sahar Elahi
- Department of Biomedical Engineering, University of Texas at Austin, 107 W Dean Keeton Street Stop C0800, Austin, TX, 78712, USA,
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41
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Phipps JE, Vela D, Hoyt T, Halaney DL, Mancuso JJ, Buja LM, Asmis R, Milner TE, Feldman MD. Macrophages and intravascular OCT bright spots: a quantitative study. JACC Cardiovasc Imaging 2014; 8:63-72. [PMID: 25499133 DOI: 10.1016/j.jcmg.2014.07.027] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 06/25/2014] [Accepted: 07/16/2014] [Indexed: 12/15/2022]
Abstract
OBJECTIVES This study hypothesized that bright spots in intravascular optical coherence tomography (IVOCT) images may originate by colocalization of plaque materials of differing indexes of refraction. To quantitatively identify bright spots, we developed an algorithm that accounts for factors including tissue depth, distance from light source, and signal-to-noise ratio. We used this algorithm to perform a bright spot analysis of IVOCT images and compared these results with histological examination of matching tissue sections. BACKGROUND Bright spots are thought to represent macrophages in IVOCT images, and studies of alternative etiologies have not been reported. METHODS Fresh human coronary arteries (n = 14 from 10 hearts) were imaged with IVOCT in a mock catheterization laboratory and then processed for histological analysis. The quantitative bright spot algorithm was applied to all images. RESULTS Results are reported for 1,599 IVOCT images co-registered with histology. Macrophages alone were responsible for only 23% of the bright spot-positive regions, although they were present in 57% of bright spot-positive regions (as determined by histology). Additional etiologies for bright spots included cellular fibrous tissue (8%), interfaces between calcium and fibrous tissue (10%), calcium and lipids (5%), and fibrous cap and lipid pool (3%). Additionally, we showed that large pools of macrophages in CD68(+) histology sections corresponded to dark regions in comparative IVOCT images; this is due to the fact that a pool of lipid-rich macrophages will have the same index of refraction as a pool of lipid and thus will not cause bright spots. CONCLUSIONS Bright spots in IVOCT images were correlated with a variety of plaque components that cause sharp changes in the index of refraction. Algorithms that incorporate these correlations may be developed to improve the identification of some types of vulnerable plaque and allow standardization of IVOCT image interpretation.
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Affiliation(s)
- Jennifer E Phipps
- University of Texas Health Science Center San Antonio, San Antonio, Texas
| | | | - Taylor Hoyt
- University of Texas Health Science Center San Antonio, San Antonio, Texas
| | - David L Halaney
- University of Texas Health Science Center San Antonio, San Antonio, Texas; Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, Texas
| | - J Jacob Mancuso
- University of Texas Health Science Center San Antonio, San Antonio, Texas
| | | | - Reto Asmis
- University of Texas Health Science Center San Antonio, San Antonio, Texas
| | | | - Marc D Feldman
- University of Texas Health Science Center San Antonio, San Antonio, Texas; Department of Veterans Affairs, South Texas Veterans Health Care System, San Antonio, Texas.
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Kim J, Kang HW, Oh J, Milner TE. Thermoelastic displacement measured by DP-OCT for detecting vulnerable plaques. Biomed Opt Express 2014; 5:474-84. [PMID: 24575342 PMCID: PMC3920878 DOI: 10.1364/boe.5.000474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Revised: 10/01/2013] [Accepted: 01/08/2014] [Indexed: 05/04/2023]
Abstract
The detection of thermoelastic displacement by differential phase optical coherence tomography (DP-OCT) was analytically evaluated for identifying atherosclerotic plaques. Analytical solutions were developed to understand the dynamics of physical distribution of point hear sources during/after laser irradiation on thermoelastic responses of MION-injected tissue. Both analytical and experimental results demonstrated a delayed peak displacement along with slow decay after laser pulse due to heterogeneous distribution of the point heat sources. Detailed description of the heat sources in tissue as well as integration of a scanning mirror can improve computational accuracy as well as clinical applicability of DP-OCT for diagnosing vulnerable plaque.
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Affiliation(s)
- Jihoon Kim
- Fundamental Technology Group, Samsung-Electro Mechanics, Suwon 443-743, South Korea
| | - Hyun Wook Kang
- Department of Biomedical Engineering, Pukyong National University, Busan 608-737, South Korea
- Center for Marine-Integrated Biomedical Technology, Pukyong National University, Busan 608-737, South Korea
| | - Junghwan Oh
- Department of Biomedical Engineering, Pukyong National University, Busan 608-737, South Korea
- Center for Marine-Integrated Biomedical Technology, Pukyong National University, Busan 608-737, South Korea
| | - Thomas E. Milner
- Department of Biomedical Engineering, University of Texas at Austin, Austin, Texas 78712, USA
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Yin B, Wang B, Rylander HG, Milner TE. Degradation in the degree of polarization in human retinal nerve fiber layer. J Biomed Opt 2014; 19:16001. [PMID: 24390374 PMCID: PMC3881105 DOI: 10.1117/1.jbo.19.1.016001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Revised: 12/02/2013] [Accepted: 12/04/2013] [Indexed: 05/21/2023]
Abstract
Using a fiber-based swept-source (SS) polarization-sensitive optical coherence tomography (PS-OCT) system, we investigate the degree of polarization (DOP) of light backscattered from the retinal nerve fiber layer (RNFL) in normal human subjects. Algorithms for processing data were developed to analyze the deviation in phase retardation and intensity of backscattered light in directions parallel and perpendicular to the nerve fiber axis (fast and slow axes of RNFL). Considering superior, inferior, and nasal quadrants, we observe the strongest degradation in the DOP with increasing RNFL depth in the temporal quadrant. Retinal ganglion cell axons in normal human subjects are known to have the smallest diameter in the temporal quadrant, and the greater degradation observed in the DOP suggests that higher polarimetric noise may be associated with neural structure in the temporal RNFL. The association between depth degradation in the DOP and RNFL structural properties may broaden the utility of PS-OCT as a functional imaging technique.
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Affiliation(s)
- Biwei Yin
- University of Texas at Austin, Departments of Electrical and Computer Engineering, 1 University Station C0803, Austin, Texas 78712
- Address all correspondence to: Biwei Yin, E-mail:
| | - Bingqing Wang
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station, C0800, Austin, Texas 78712
| | - Henry G. Rylander
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station, C0800, Austin, Texas 78712
| | - Thomas E. Milner
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station, C0800, Austin, Texas 78712
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44
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Wang B, Yin B, Dwelle J, Rylander HG, Markey MK, Milner TE. Path-length-multiplexed scattering-angle-diverse optical coherence tomography for retinal imaging. Opt Lett 2013; 38:4374-7. [PMID: 24177097 PMCID: PMC3903005 DOI: 10.1364/ol.38.004374] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
A low-resolution path-length-multiplexed scattering angle diverse optical coherence tomography (PM-SAD-OCT) is constructed to investigate the scattering properties of the retinal nerve fiber layer (RNFL). Low-resolution PM-SAD-OCT retinal images acquired from a healthy human subject show the variation of RNFL scattering properties at retinal locations around the optic nerve head. The results are consistent with known retinal ganglion cell neural anatomy and principles of light scattering. Application of PM-SAD-OCT may provide potentially valuable diagnostic information for clinical retinal imaging.
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Affiliation(s)
- Bingqing Wang
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Biwei Yin
- Department of Electrical and Computer Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Jordan Dwelle
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - H. Grady Rylander
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Mia K. Markey
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
| | - Thomas E. Milner
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
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Elahi S, Feldman MD, Dijkstra J, Milner TE. Intravascular optical coherence tomography measurement of size and apposition of metallic stents. Biomed Opt Express 2013; 4:1876-1882. [PMID: 24156050 PMCID: PMC3799652 DOI: 10.1364/boe.4.001876] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2013] [Revised: 07/24/2013] [Accepted: 07/30/2013] [Indexed: 06/02/2023]
Abstract
Effect of beam size and catheter position on the apparent size and apposition of metallic stent struts in IVOCT images were examined. Micro-CT data was employed to determine light - stent strut interactions. Simulated results suggest that location of the reflecting regions depend on relative orientation and position of stent struts to the IVOCT beam. Erroneous stent apposition measurements can occur when the IVOCT catheter is at an eccentric position. A method that mitigates stent strut apposition measurement errors is proposed.
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Affiliation(s)
- Sahar Elahi
- Department of Biomedical Engineering, University of Texas at Austin, USA
| | - Marc D. Feldman
- Division of Cardiology, Department of Medicine, University of Texas Health Science Center at San Antonio, and the South Texas Veterans Affairs Health Care System, San Antonio, Texas, USA
| | - Jouke Dijkstra
- Department of Radiology, Leiden University Medical Center, the Netherlands
| | - Thomas E. Milner
- Department of Biomedical Engineering, University of Texas at Austin, USA
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Qiu J, Neev J, Wang T, Milner TE. Deep subsurface cavities in skin utilizing mechanical optical clearing and femtosecond laser ablation. Lasers Surg Med 2013; 45:383-90. [PMID: 23754315 DOI: 10.1002/lsm.22150] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/03/2013] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND OBJECTIVES High precision subsurface ablation can be produced in transparent materials using femtosecond laser pulses and multiphoton absorption. Light scattering limits application of the same technique to most biological tissues. Previously, subsurface ablation was demonstrated at superficial depths (50-250 µm) in highly scattering tissues including murine skin and human sclera. We report application of mechanical optical clearing to produce deeper subsurface femtosecond ablation in rodent skin. Ability to target deeper structures in skin using subsurface ablation may allow novel clinical applications for dermatological laser surgery. STUDY DESIGN/MATERIALS AND METHODS Operation of a prototype tissue optical clearing device (TOCD) was verified with white light photography in ex vivo rodent skin. A focused femtosecond beam transmitted through the TOCD and was scanned across rodent skin to produce subsurface ablation at increasing focal depths. Histological sections with H&E staining of the laser irradiated rodent skin were examined for subsurface ablation features following laser irradiation. RESULTS Subsurface cavities were observed as deep as 1.7 mm below the skin surface in histological tissue sections. Diameter of subsurface cavities varied from tens of microns to over 100 μm. Subsurface cavities produced by scanning the focused femtosecond beam were contiguous and formed a continuous cut. Mechanical disruption of the overlying tissues was not observed. CONCLUSIONS Mechanical optical clearing can be applied directly to in situ rodent skin and produces an optical clearing effect. High precision subsurface ablation can be produced at positions substantially deeper than previously demonstrated. Future studies may be targeted in in vivo human skin to investigate potential clinical applications of subsurface femtosecond ablation using mechanical optical clearing.
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Affiliation(s)
- Jinze Qiu
- Department of Biomedical Engineering, The University of Texas at Austin, Texas 78712, USA.
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Yin B, Kuranov RV, McElroy AB, Kazmi S, Dunn AK, Duong TQ, Milner TE. Dual-wavelength photothermal optical coherence tomography for imaging microvasculature blood oxygen saturation. J Biomed Opt 2013; 18:56005. [PMID: 23640076 PMCID: PMC3642243 DOI: 10.1117/1.jbo.18.5.056005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A swept-source dual-wavelength photothermal (DWP) optical coherence tomography (OCT) system is demonstrated for quantitative imaging of microvasculature oxygen saturation. DWP-OCT is capable of recording three-dimensional images of tissue and depth-resolved phase variation in response to photothermal excitation. A 1,064-nm OCT probe and 770-nm and 800-nm photothermal excitation beams are combined in a single-mode optical fiber to measure microvasculature hemoglobin oxygen saturation (SO(2)) levels in phantom blood vessels with a range of blood flow speeds (0 to 17 mm/s). A 50-μm-diameter blood vessel phantom is imaged, and SO(2) levels are measured using DWP-OCT and compared with values provided by a commercial oximeter at various blood oxygen concentrations. The influences of blood flow speed and mechanisms of SNR phase degradation on the accuracy of SO(2) measurement are identified and investigated.
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Affiliation(s)
- Biwei Yin
- University of Texas at Austin, Departments of Electrical and Computer Engineering, 1 University Station C0803, Austin, Texas 78712
| | - Roman V. Kuranov
- University of Texas Health Science Center at San Antonio, Department of Ophthalmology, 7703 Floyd Curl Drive, San Antonio, Texas 78229
- Address all correspondence to: Roman V. Kuranov, University of Texas Health Science Center at San Antonio, Department of Ophthalmology, 7703 Floyd Curl Drive, San Antonio, Texas 78229. Tel: 210-567-8402; Fax: 210-567-8413; E-mail:
| | - Austin B. McElroy
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
| | - Shams Kazmi
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
| | - Andrew K. Dunn
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
| | - Timothy Q. Duong
- University of Texas Health Science Center at San Antonio, Department of Ophthalmology, 7703 Floyd Curl Drive, San Antonio, Texas 78229
| | - Thomas E. Milner
- University of Texas at Austin, Department of Biomedical Engineering, 1 University Station C0800, Austin, Texas 78712
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Wang T, Halaney D, Ho D, Feldman MD, Milner TE. Two-photon luminescence properties of gold nanorods. Biomed Opt Express 2013; 4:584-95. [PMID: 23577293 PMCID: PMC3617720 DOI: 10.1364/boe.4.000584] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 01/26/2013] [Accepted: 01/27/2013] [Indexed: 05/19/2023]
Abstract
Gold nanorods can be internalized by macrophages (an important early cellular marker in atherosclerosis and cancer) and used as an imaging contrast agent for macrophage targeting. Objective of this study is to compare two-photon luminescence (TPL) properties of four aspect ratios of gold nanorods with surface plasmon resonance at 700, 756, 844 and 1060 nm respectively. TPL from single nanorods and Rhodamine 6G particles was measured using a laser-scanning TPL microscope. Nanorod TPL emission spectrum was recorded by a spectrometer. Quadratic dependence of luminescence intensity on excitation power (confirming a TPL process) was observed below a threshold (e.g., <1.6 mW), followed by photobleaching at higher power levels. Dependence of nanorod TPL intensity on excitation wavelength indicated that the two-photon action cross section (TPACS) is plasmon-enhanced. Largest TPACS of a single nanorod (12271 GM) was substantially larger than a single Rhodamine 6G particle (25 GM) at 760 nm excitation. Characteristics of nanorod TPL emission spectrum can be explained by plasmon-enhanced interband transition of gold. Comparison results of TPL brightness, TPACS and emission spectrum of nanorods can guide selection of optimal contrast agent for selected imaging applications.
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Affiliation(s)
- Tianyi Wang
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - David Halaney
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA
- South Texas Veterans Health Care System, San Antonio, Texas 78229, USA
| | - Derek Ho
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
| | - Marc D. Feldman
- Division of Cardiology, University of Texas Health Science Center, 7703 Floyd Curl Drive, San Antonio, Texas 78229, USA
- South Texas Veterans Health Care System, San Antonio, Texas 78229, USA
| | - Thomas E. Milner
- Department of Biomedical Engineering, University of Texas at Austin, 1 University Station C0800, Austin, Texas 78712, USA
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Ma LL, Borwankar AU, Willsey BW, Yoon KY, Tam JO, Sokolov KV, Feldman MD, Milner TE, Johnston KP. Growth of textured thin Au coatings on iron oxide nanoparticles with near infrared absorbance. Nanotechnology 2013; 24:025606. [PMID: 23238021 PMCID: PMC3893819 DOI: 10.1088/0957-4484/24/2/025606] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A homologous series of Au coated iron oxide nanoparticles with hydrodynamic diameters smaller than 60 nm was synthesized with very low Au-to-iron mass ratios, as low as 0.15. The hydrodynamic diameter was determined by dynamic light scattering and the composition by atomic absorption spectroscopy and energy dispersive x-ray spectroscopy. Unusually low Au precursor supersaturation levels were utilized to nucleate and grow Au coatings on iron oxide relative to the formation of pure Au nanoparticles. This approach produced unusually thin coatings by lowering autocatalytic growth of Au on Au, as shown by transmission electron microscopy. Nearly all of the nanoparticles were attracted by a magnet, indicating a minimal number of pure Au particles. The coatings were sufficiently thin to shift the surface plasmon resonance to the near infrared with large extinction coefficients, despite the small particle hydrodynamic diameters observed from dynamic light scattering to be less than 60 nm.
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Affiliation(s)
- L L Ma
- Department of Chemical Engineering, University of Texas at
Austin, Austin, Texas 78712
- South Texas Veterans Health Care System, San Antonio, Texas
78229
| | - A U Borwankar
- Department of Chemical Engineering, University of Texas at
Austin, Austin, Texas 78712
| | - B W Willsey
- Department of Chemical Engineering, University of Texas at
Austin, Austin, Texas 78712
| | - K Y Yoon
- Department of Chemical Engineering, University of Texas at
Austin, Austin, Texas 78712
| | - J O Tam
- Department of Biomedical Engineering, University of Texas
at Austin, Austin, Texas 78712
| | - K V Sokolov
- Department of Biomedical Engineering, University of Texas
at Austin, Austin, Texas 78712
- Departments of Biomedical Engineering and Imaging Physics,
M.D. Anderson Cancer Center, Houston, Texas 77030
| | - M D Feldman
- South Texas Veterans Health Care System, San Antonio, Texas
78229
- Division of Cardiology, Department of Medicine, University
of Texas Health Science Center at San Antonio, San Antonio, Texas 78229
| | - T E Milner
- Department of Biomedical Engineering, University of Texas
at Austin, Austin, Texas 78712
| | - K P Johnston
- Department of Chemical Engineering, University of Texas at
Austin, Austin, Texas 78712
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50
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Hammer DX, Mujat M, Ferguson RD, Iftimia N, Escobedo D, Jenkins JT, Lim H, Milner TE, Feldman MD. Imaging flow dynamics in murine coronary arteries with spectral domain optical Doppler tomography. Biomed Opt Express 2012; 3:701-14. [PMID: 22574259 PMCID: PMC3345800 DOI: 10.1364/boe.3.000701] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/27/2012] [Accepted: 01/18/2012] [Indexed: 05/11/2023]
Abstract
Blood flow in murine epicardial and intra-myocardial coronary arteries was measured in vivo with spectral domain optical Doppler tomography (SD-ODT). Videos at frame rates up to 180 fps were collected and processed to extract phase shifts associated with moving erythrocytes in the coronary arteries. Radial averaging centered on the vessel lumen provided spatial smoothing of phase noise in a single cross-sectional frame for instantaneous peak velocity measurement without distortion of the flow profile. Temporal averaging synchronized to the cardiac cycle (i.e., gating) was also performed to reduce phase noise, although resulting in lower flow profiles. The vessel angle with respect to incident imaging beam was measured with three-dimensional raster scans collected from the same region as the high speed cross-sectional scans. The variability in peak phase measurement was 10-15% from cycle to cycle on a single animal but larger for measurements among animals. The inter-subject variability is attributed to factors related to real physiological and anatomical differences, instrumentation variables, and measurement error. The measured peak instantaneous flow velocity in a ~40-µm diameter vessel was 23.5 mm/s (28 kHz Doppler phase shift). In addition to measurement of the flow velocity, we observed several dynamic features of the vessel and surrounding myocardium in the intensity and phase sequences, including asymmetric vessel deformation and rapid flow reversal immediately following maximum flow, in confirmation of known coronary artery flow dynamics. SD-ODT is an optical imaging tool that can provide in vivo measures of structural and functional information on cardiac function in small animals.
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Affiliation(s)
- Daniel X. Hammer
- Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810, USA
| | - Mircea Mujat
- Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810, USA
| | - R. Daniel Ferguson
- Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810, USA
| | - Nicusor Iftimia
- Physical Sciences Inc., 20 New England Business Center, Andover, MA 01810, USA
| | - Daniel Escobedo
- Department of Cardiology, University of Texas Health Science Center, San Antonio, TX 78248, USA
| | - J. Travis Jenkins
- Department of Cardiology, University of Texas Health Science Center, San Antonio, TX 78248, USA
| | - Hyunji Lim
- Department of Electrical Engineering, University of Texas, Austin, TX 78712, USA
| | - Thomas E. Milner
- Department of Electrical Engineering, University of Texas, Austin, TX 78712, USA
| | - Marc D. Feldman
- Department of Cardiology, University of Texas Health Science Center, San Antonio, TX 78248, USA
- Veterans Heath Care System, San Antonio, TX 78248
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