1
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Adalian D, Madero X, Chen S, Jilani M, Smith RD, Li S, Ahlbrecht C, Cardenas J, Agarwal A, Emami A, Plettenburg O, Petillo PA, Scherer A. Patterned thin film enzyme electrodes via spincoating and glutaraldehyde vapor crosslinking: towards scalable fabrication of integrated sensor-on-CMOS devices. LAB ON A CHIP 2024. [PMID: 39099534 DOI: 10.1039/d4lc00206g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/06/2024]
Abstract
Effective continuous glucose monitoring solutions require consistent sensor performance over the lifetime of the device, a manageable variance between devices, and the capability of high volume, low cost production. Here we present a novel and microfabrication-compatible method of depositing and stabilizing enzyme layers on top of planar electrodes that can aid in the mass production of sensors while also improving their consistency. This work is focused on the fragile biorecognition layer as that has been a critical difficulty in the development of microfabricated sensors. We test this approach with glucose oxidase (GOx) and evaluate the sensor performance with amperometric measurements of in vitro glucose concentrations. Spincoating was used to deposit a uniform enzyme layer across a wafer, which was subsequently immobilized via glutaraldehyde vapor crosslinking and patterned via liftoff. This yielded an approximately 300 nm thick sensing layer which was applied to arrays of microfabricated platinum electrodes built on blank wafers. Taking advantage of their planar array format, measurements were then performed in high-throughput parallel instrumentation. Due to their thin structure, the coated electrodes exhibited subsecond stabilization times after the bias potential was applied. The deposited enzyme layers were measured to provide a sensitivity of 2.3 ± 0.2 μA mM-1 mm-2 with suitable saturation behavior and minimal performance shift observed over extended use. The same methodology was then demonstrated directly on top of wireless CMOS potentiostats to build a monolithic sensor with similar measured performance. This work demonstrates the effectiveness of the combination of spincoating and vapor stabilization processes for wafer scale enzymatic sensor functionalization and the potential for scalable fabrication of monolithic sensor-on-CMOS devices.
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Affiliation(s)
- Dvin Adalian
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Xiomi Madero
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Samson Chen
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Musab Jilani
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Richard D Smith
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Songtai Li
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Christin Ahlbrecht
- Institute for Medicinal Chemistry, Molecular Targets and Therapeutics Center, Helmholtz Center Munich, Neuherberg, Germany
| | - Juan Cardenas
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Abhinav Agarwal
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Azita Emami
- California Institute of Technology, Pasadena, CA 91125, USA.
| | - Oliver Plettenburg
- Institute for Medicinal Chemistry, Molecular Targets and Therapeutics Center, Helmholtz Center Munich, Neuherberg, Germany
| | - Peter A Petillo
- Design-Zyme LLC, 4950 Research Park Way, Lawrence, Kansas 66047, USA
| | - Axel Scherer
- California Institute of Technology, Pasadena, CA 91125, USA.
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2
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Chimene D, Saleem W, Longbottom N, Ko B, Jeevarathinam AS, Horn S, McShane MJ. Long-Term Evaluation of Inserted Nanocomposite Hydrogel-Based Phosphorescent Oxygen Biosensors: Evolution of Local Tissue Oxygen Levels and Foreign Body Response. ACS APPLIED BIO MATERIALS 2024; 7:3964-3980. [PMID: 38809780 PMCID: PMC11190996 DOI: 10.1021/acsabm.4c00336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2024] [Revised: 05/08/2024] [Accepted: 05/09/2024] [Indexed: 05/31/2024]
Abstract
Phosphorescence-based oxygen-sensing hydrogels are a promising platform technology for an upcoming generation of insertable biosensors that are smaller, softer, and potentially more biocompatible than earlier designs. However, much remains unknown about their long-term performance and biocompatibility in vivo. In this paper, we design and evaluate a range of hydrogel sensors that contain oxygen-sensitive phosphors stabilized by micro- and nanocarrier systems. These devices demonstrated consistently good performance and biocompatibility in young adult rats for over three months. This study thoroughly establishes the biocompatibility and long-term suitability of phosphorescence lifetime sensors in vivo, providing the groundwork for expansion of this platform technology into a family of small, unobtrusive biosensors for a range of clinically relevant metabolites.
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Affiliation(s)
- David Chimene
- Department
of Biomedical Engineering, Texas A&M
University, College
Station, Texas 77843, United States
| | - Waqas Saleem
- Department
of Biomedical Engineering, Texas A&M
University, College
Station, Texas 77843, United States
| | - Nichole Longbottom
- Department
of Biomedical Engineering, Texas A&M
University, College
Station, Texas 77843, United States
- Department
of Veterinary Anatomy and Pathobiology, Texas A&M University, College Station, Texas 77843, United States
| | - Brian Ko
- Department
of Biomedical Engineering, Texas A&M
University, College
Station, Texas 77843, United States
| | | | - Staci Horn
- Department
of Biomedical Engineering, Texas A&M
University, College
Station, Texas 77843, United States
- Department
of Veterinary Anatomy and Pathobiology, Texas A&M University, College Station, Texas 77843, United States
| | - Michael J. McShane
- Department
of Biomedical Engineering, Texas A&M
University, College
Station, Texas 77843, United States
- Department
of Materials Science & Engineering, Texas A&M University, College Station, Texas 77843, United States
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3
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Lielpetere A, Jayakumar K, Leech D, Schuhmann W. Cross-Linkable Polymer-Based Multi-layers for Protecting Electrochemical Glucose Biosensors against Uric Acid, Ascorbic Acid, and Biofouling Interferences. ACS Sens 2023; 8:1756-1765. [PMID: 36943936 PMCID: PMC10152486 DOI: 10.1021/acssensors.3c00050] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The lifetime of implantable electrochemical glucose monitoring devices is limited due to the foreign body response and detrimental effects from ascorbic acid (AA) and uric acid (UA) interferents that are components of physiological media. Polymer coatings can be used to shield biosensors from these interferences and prolong their functional lifetime. This work explored several approaches to protect redox polymer-based glucose biosensors against such interferences by designing six targeted multi-layer sensor architectures. Biological interferents, like cells and proteins, and UA and AA interferents were found to have individual effects on the current density and operational stability of glucose biosensors, requiring individual protection and treatment. Protection against biofouling can be achieved using a poly(2-methacryloyloxyethyl phosphorylcholine-co-glycidyl methacrylate) (MPC) zwitterionic polymer coating. An enzyme-scavenging approach was compared to electrostatic repulsion by negatively charged polymers for protection against AA and UA interferences. A multi-layer novel polymer design (PD) system consisting of a cross-linkable negatively charged polyvinylimidazole-polysulfostyrene co-polymer inner layer and a cross-linkable MPC zwitterionic polymer outer layer showed the best protection against AA, UA, and biological interferences. The sensor protected using the novel PD shield displayed the lowest mean absolute relative difference between the glucose reading without the interferent and the reading value with the interferent present and also displayed the lowest variability in sensor readings in complex media. For sensor measurements in artificial plasma, the novel PD extends the linear range (R2 = 0.99) of the sensor from 0-10 mM for the control to 0-20 mM, shows a smaller decrease in sensitivity, and retains high current densities. The application of PD multi-target coating improves sensor performance in complex media and shows promise for use in sensors operating in real conditions.
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Affiliation(s)
- Anna Lielpetere
- Analytical Chemistry-Center for Electrochemical Sciences, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstr. 150, 44780 Bochum, Germany
| | - Kavita Jayakumar
- School of Biological & Chemical Sciences, University of Galway, University Road, H91 TK33 Galway, Ireland
| | - Dónal Leech
- School of Biological & Chemical Sciences, University of Galway, University Road, H91 TK33 Galway, Ireland
| | - Wolfgang Schuhmann
- Analytical Chemistry-Center for Electrochemical Sciences, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, Universitätsstr. 150, 44780 Bochum, Germany
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4
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Taylor JB, Malone-Povolny MJ, Merricks EP, Wimsey LE, Soliman D, Nichols TC, Wallet SM, Maile R, Schoenfisch MH. Mechanisms of Foreign Body Response Mitigation by Nitric Oxide Release. Int J Mol Sci 2022; 23:11635. [PMID: 36232937 PMCID: PMC9569454 DOI: 10.3390/ijms231911635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/14/2022] [Accepted: 09/23/2022] [Indexed: 11/06/2022] Open
Abstract
Implantable glucose biosensors provide real-time information about blood glucose fluctuations, but their utility and accuracy are time-limited due to the foreign body response (FBR) following their insertion beneath the skin. The slow release of nitric oxide (NO), a gasotransmitter with inflammation regulatory properties, from a sensor surface has been shown to dramatically improve sensors' analytical biocompatibility by reducing the overall FBR response. Indeed, work in a porcine model suggests that as long as the implants (sensors) continue to release NO, even at low levels, the inflammatory cell infiltration and resulting collagen density are lessened. While these studies strongly support the benefits of NO release in mitigating the FBR, the mechanisms through which exogenous NO acts on the surrounding tissue, especially under the condition of hyperglycemia, remain vague. Such knowledge would inform strategies to refine appropriate NO dosage and release kinetics for optimal therapeutic activity. In this study, we evaluated mediator, immune cell, and mRNA expression profiles in the local tissue microenvironment surrounding implanted sensors as a function of NO release, diabetes, and implantation duration. A custom porcine wound healing-centric multiplex gene array was developed for nanoString barcoding analysis. Tissues adjacent to sensors with sustained NO release abrogated the implant-induced acute and chronic FBR through modulation of the tissue-specific immune chemokine and cytokine microenvironment, resulting in decreased cellular recruitment, proliferation, and activation at both the acute (7-d) and chronic (14-d) phases of the FBR. Further, we found that sustained NO release abrogated the implant-induced acute and chronic foreign body response through modulation of mRNA encoding for key immunological signaling molecules and pathways, including STAT1 and multiple STAT1 targets including MAPK14, IRAK4, MMP2, and CXCL10. The condition of diabetes promoted a more robust FBR to the implants, which was also controlled by sustained NO release.
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Affiliation(s)
- James B Taylor
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Maggie J Malone-Povolny
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Elizabeth P Merricks
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Lauren E Wimsey
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Daniel Soliman
- Department of Surgery, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
- Division of Oral and Craniofacial Health Sciences, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Timothy C Nichols
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Shannon M Wallet
- Division of Oral and Craniofacial Health Sciences, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Robert Maile
- Department of Surgery, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
- Curriculum of Toxicology, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
| | - Mark H Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
- Division of Pharmacoengineering and Molecular Pharmaceutics, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, NC 27599, USA
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5
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Didyuk O, Econom N, Guardia A, Livingston K, Klueh U. Continuous Glucose Monitoring Devices: Past, Present, and Future Focus on the History and Evolution of Technological Innovation. J Diabetes Sci Technol 2021; 15:676-683. [PMID: 31931614 PMCID: PMC8120065 DOI: 10.1177/1932296819899394] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The concept of implantable glucose sensors has been promulgated for more than 40 years. It is now accepted that continuous glucose monitoring (CGM) increases quality of life by allowing informed diabetes management decisions as a result of more optimized glucose control. The focus of this article is to provide a brief overview of the CGM market history, emerging technologies, and the foreseeable challenges for the next CGM generations as well as proposing possible solutions in an effort to advance the next generation of implantable sensor.
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Affiliation(s)
- Olesya Didyuk
- Department of Biological Sciences, IBio
(Integrative Biosciences Center), Wayne State University, Detroit, MI, USA
| | - Nicolas Econom
- Biomedical Engineering, IBio
(Integrative Biosciences Center), Wayne State University, Detroit, MI, USA
| | - Angelica Guardia
- Biomedical Engineering, IBio
(Integrative Biosciences Center), Wayne State University, Detroit, MI, USA
| | - Kelsey Livingston
- Biomedical Engineering, IBio
(Integrative Biosciences Center), Wayne State University, Detroit, MI, USA
| | - Ulrike Klueh
- Biomedical Engineering, IBio
(Integrative Biosciences Center), Wayne State University, Detroit, MI, USA
- Ulrike Klueh, PhD, Department of Biomedical
Engineering, Wayne State University, 263 Farmington Avenue, Detroit, MI 48202,
USA.
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6
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Malone-Povolny MJ, Bradshaw TM, Merricks EP, Long CT, Nichols TC, Schoenfisch MH. Combination of Nitric Oxide Release and Surface Texture for Mitigating the Foreign Body Response. ACS Biomater Sci Eng 2021; 7:2444-2452. [PMID: 33848421 DOI: 10.1021/acsbiomaterials.1c00022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The tissue response to polyurethane (PU)-coated implants employing active and/or passive FBR mitigation techniques was evaluated over a 28 day study in a diabetic swine model. Active FBR mitigation was achieved through the sustained release of nitric oxide (NO) from a mesoporous silica nanoparticle-doped PU coating. Passive FBR mitigation was achieved through the application of a foam- or fiber-based topcoat. These topcoats were designed to possess topographical features known to promote tissue integration with foam-coated implants having pore sizes of approximately 50 μm and fiber-coated implants consisting of fiber diameters of less than 1 μm. Nitric oxide-release profiles were minimally impacted by the presence of either topcoat. Inflammatory cell density and collagen density at the implant-tissue interface were assessed at 7, 14, 21, and 28 days following implantation. Nitric oxide-releasing implants had significantly lower inflammatory cell density and collagen density than non-NO-releasing controls. The presence of a topcoat did not significantly impact inflammatory cell density, though top-coated textured implants resulted in significantly lower collagen density, irrespective of NO release. Overall, coatings that combine NO release with surface texture demonstrated the greatest potential for tissue-based biomedical device applications.
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Affiliation(s)
- Maggie J Malone-Povolny
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina 27599, United States
| | - Taron M Bradshaw
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina 27599, United States
| | - Elizabeth P Merricks
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina 27599, United States
| | - C Tyler Long
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina 27599, United States
| | - Timothy C Nichols
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina 27599, United States
| | - Mark H Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina 27599, United States
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7
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Welch NG, Winkler DA, Thissen H. Antifibrotic strategies for medical devices. Adv Drug Deliv Rev 2020; 167:109-120. [PMID: 32553685 DOI: 10.1016/j.addr.2020.06.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/02/2020] [Accepted: 06/08/2020] [Indexed: 12/13/2022]
Abstract
A broad range of medical devices initiate an immune reaction known as the foreign body response (FBR) upon implantation. Here, collagen deposition at the surface of the implant occurs as a result of the FBR, ultimately leading to fibrous encapsulation and, in many cases, reduced function or failure of the device. Despite significant efforts, the prevention of fibrotic encapsulation has not been realized at this point in time. However, many next-generation medical technologies including cellular therapies, sensors and devices depend on the ability to modulate and control the FBR. For these technologies to become viable, significant advances must be made in understanding the underlying mechanism of this response as well as in the methods modulating this response. In this review, we highlight recent advances in the development of materials and coatings providing a reduced FBR and emphasize key characteristics of high-performing approaches. We also provide a detailed overview of the state-of-the-art in strategies relying on controlled drug release, the surface display of bioactive signals, materials-based approaches, and combinations of these approaches. Finally, we offer perspectives on future directions in this field.
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8
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Monitoring with In Vivo Electrochemical Sensors: Navigating the Complexities of Blood and Tissue Reactivity. SENSORS 2020; 20:s20113149. [PMID: 32498360 PMCID: PMC7308849 DOI: 10.3390/s20113149] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/29/2020] [Accepted: 05/31/2020] [Indexed: 12/18/2022]
Abstract
The disruptive action of an acute or critical illness is frequently manifest through rapid biochemical changes that may require continuous monitoring. Within these changes, resides trend information of predictive value, including responsiveness to therapy. In contrast to physical variables, biochemical parameters monitored on a continuous basis are a largely untapped resource because of the lack of clinically usable monitoring systems. This is despite the huge testing repertoire opening up in recent years in relation to discrete biochemical measurements. Electrochemical sensors offer one of the few routes to obtaining continuous readout and, moreover, as implantable devices information referable to specific tissue locations. This review focuses on new biological insights that have been secured through in vivo electrochemical sensors. In addition, the challenges of operating in a reactive, biological, sample matrix are highlighted. Specific attention is given to the choreographed host rejection response, as evidenced in blood and tissue, and how this limits both sensor life time and reliability of operation. Examples will be based around ion, O2, glucose, and lactate sensors, because of the fundamental importance of this group to acute health care.
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9
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Design of a Sandwich Hierarchically Porous Membrane with Oxygen Supplement Function for Implantable Glucose Sensor. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10082848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
This study aims to develop an oxygen regeneration layer sandwiched between multiple porous polyurethanes (PU) to improve the performance of implantable glucose sensors. Sensors were prepared by coating electrodes with platinum nanoparticles, Nafion, glucose oxidase and sandwich hierarchically porous membrane with an oxygen supplement function (SHPM-OS). The SHPM-OS consisted of a hierarchically porous structure synthesized by polyethylene glycol and PU and a catalase (Cat) layer that was coated between hierarchical membranes and used to balance the sensitivity and linearity of glucose sensors, as well as reduce the influence of oxygen deficiency during monitoring. Compared with the sensitivity and linearity of traditional non-porous (NO-P) sensors (35.95 nA/mM, 0.9987, respectively) and single porous (SGL-P) sensors (45.3 nA /mM, 0.9610, respectively), the sensitivity and linearity of the SHPM-OS sensor was 98.45 nA/mM and 0.9989, respectively, which was more sensitive with higher linearity. The sensor showed a response speed of five seconds and a relative sensitivity of 90% in the first 10 days and remained 78% on day 20. This sensor coated with SHPM-OS achieved rapid responses to changes of glucose concentration while maintaining high linearity for long monitoring times. Thus, it may reduce the difficulty of back-end hardware module development and assist with effective glucose self-management for people with diabetes.
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10
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McClatchey PM, McClain ES, Williams IM, Malabanan CM, James FD, Lord PC, Gregory JM, Cliffel DE, Wasserman DH. Fibrotic Encapsulation Is the Dominant Source of Continuous Glucose Monitor Delays. Diabetes 2019; 68:1892-1901. [PMID: 31399432 PMCID: PMC6754243 DOI: 10.2337/db19-0229] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 07/17/2019] [Indexed: 01/06/2023]
Abstract
Continuous glucose monitor (CGM) readings are delayed relative to blood glucose, and this delay is usually attributed to the latency of interstitial glucose levels. However, CGM-independent data suggest rapid equilibration of interstitial glucose. This study sought to determine the loci of CGM delays. Electrical current was measured directly from CGM electrodes to define sensor kinetics in the absence of smoothing algorithms. CGMs were implanted in mice, and sensor versus blood glucose responses were measured after an intravenous glucose challenge. Dispersion of a fluorescent glucose analog (2-NBDG) into the CGM microenvironment was observed in vivo using intravital microscopy. Tissue deposited on the sensor and nonimplanted subcutaneous adipose tissue was then collected for histological analysis. The time to half-maximum CGM response in vitro was 35 ± 2 s. In vivo, CGMs took 24 ± 7 min to reach maximum current versus 2 ± 1 min to maximum blood glucose (P = 0.0017). 2-NBDG took 21 ± 7 min to reach maximum fluorescence at the sensor versus 6 ± 6 min in adipose tissue (P = 0.0011). Collagen content was closely correlated with 2-NBDG latency (R = 0.96, P = 0.0004). Diffusion of glucose into the tissue deposited on a CGM is substantially delayed relative to interstitial fluid. A CGM that resists fibrous encapsulation would better approximate real-time deviations in blood glucose.
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Affiliation(s)
- P Mason McClatchey
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Ethan S McClain
- Department of Chemistry, Vanderbilt University, Nashville, TN
| | - Ian M Williams
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Carlo M Malabanan
- Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN
| | - Freyja D James
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | | | - Justin M Gregory
- Ian M. Burr Division of Pediatric Endocrinology and Diabetes, Vanderbilt University School of Medicine, Nashville, TN
| | - David E Cliffel
- Department of Chemistry, Vanderbilt University, Nashville, TN
| | - David H Wasserman
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Mouse Metabolic Phenotyping Center, Vanderbilt University, Nashville, TN
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11
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Dolan EB, Varela CE, Mendez K, Whyte W, Levey RE, Robinson ST, Maye E, O'Dwyer J, Beatty R, Rothman A, Fan Y, Hochstein J, Rothenbucher SE, Wylie R, Starr JR, Monaghan M, Dockery P, Duffy GP, Roche ET. An actuatable soft reservoir modulates host foreign body response. Sci Robot 2019; 4:4/33/eaax7043. [PMID: 33137787 DOI: 10.1126/scirobotics.aax7043] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 08/01/2019] [Indexed: 12/18/2022]
Abstract
The performance of indwelling medical devices that depend on an interface with soft tissue is plagued by complex, unpredictable foreign body responses. Such devices-including breast implants, biosensors, and drug delivery devices-are often subject to a collection of biological host responses, including fibrosis, which can impair device functionality. This work describes a milliscale dynamic soft reservoir (DSR) that actively modulates the biomechanics of the biotic-abiotic interface by altering strain, fluid flow, and cellular activity in the peri-implant tissue. We performed cyclical actuation of the DSR in a preclinical rodent model. Evaluation of the resulting host response showed a significant reduction in fibrous capsule thickness (P = 0.0005) in the actuated DSR compared with non-actuated controls, whereas the collagen density and orientation were not changed. We also show a significant reduction in myofibroblasts (P = 0.0036) in the actuated group and propose that actuation-mediated strain reduces differentiation and proliferation of myofibroblasts and therefore extracellular matrix production. Computational models quantified the effect of actuation on the reservoir and surrounding fluid. By adding a porous membrane and a therapy reservoir to the DSR, we demonstrate that, with actuation, we could (i) increase transport of a therapy analog and (ii) enhance pharmacokinetics and time to functional effect of an inotropic agent. The dynamic reservoirs presented here may act as a versatile tool to further understand, and ultimately to ameliorate, the host response to implantable biomaterials.
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Affiliation(s)
- E B Dolan
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland.,Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - C E Varela
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA, USA
| | - K Mendez
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA, USA
| | - W Whyte
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA.,Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.,Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin, Dublin, Ireland.,Royal College of Surgeons in Ireland, Dublin, Ireland
| | - R E Levey
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - S T Robinson
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland.,Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin, Dublin, Ireland.,Royal College of Surgeons in Ireland, Dublin, Ireland
| | - E Maye
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - J O'Dwyer
- Biomedical Engineering, College of Engineering and Informatics, National University of Ireland Galway, Galway, Ireland.,Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - R Beatty
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - A Rothman
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Y Fan
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - J Hochstein
- Harvard-MIT Program in Health Sciences and Technology, Cambridge, MA, USA
| | - S E Rothenbucher
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - R Wylie
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland
| | - J R Starr
- Epidemiology and Biostatistics Core, The Forsyth Institute, 245 First Street, Cambridge, MA, USA
| | - M Monaghan
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.,CÚRAM, Centre for Research in Medical Devices, National University of Ireland Galway, Galway, Ireland
| | - P Dockery
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland.,CÚRAM, Centre for Research in Medical Devices, National University of Ireland Galway, Galway, Ireland
| | - G P Duffy
- Anatomy and Regenerative Medicine Institute (REMEDI), School of Medicine, College of Medicine Nursing and Health Sciences, National University of Ireland Galway, Galway, Ireland. .,Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, Trinity College Dublin, Dublin 2, Ireland.,Advanced Materials and BioEngineering Research Centre (AMBER), Trinity College Dublin, Dublin, Ireland.,Royal College of Surgeons in Ireland, Dublin, Ireland.,CÚRAM, Centre for Research in Medical Devices, National University of Ireland Galway, Galway, Ireland
| | - E T Roche
- Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA, USA. .,Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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12
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Malone-Povolny MJ, Schoenfisch MH. Extended Nitric Oxide-Releasing Polyurethanes via S-Nitrosothiol-Modified Mesoporous Silica Nanoparticles. ACS APPLIED MATERIALS & INTERFACES 2019; 11:12216-12223. [PMID: 30888145 PMCID: PMC6773253 DOI: 10.1021/acsami.8b19236] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
S-Nitrosothiol (RSNO)-modified mesoporous silica nanoparticles (MSNs) were doped into polyurethane (PU) to achieve extended NO-releasing coatings. Parameters influencing the synthesis of RSNO-functionalized nitric oxide (NO)-releasing MSNs were evaluated to elucidate the impact of pore structure on NO release characteristics. The porous particles were characterized as having larger NO payloads and longer NO release durations than those of nonporous particles, a feature attributed to the recombination of the NO radical in confined intraporous microenvironments. NO release kinetics, particle leaching, and thermal stability of the RSNO-modified MSNs dispersed in PU were evaluated as a function of PU structure to determine the feasibility of preparing a range of NO-releasing polymers for biomedical device-coating applications. The NO release kinetics from the PUs proved to be highly extended (>30 d) and consistent over a range of PU properties. Furthermore, RSNO-modified MSN leaching was not observed from the PUs. The NO release payloads were also maintained for 4 days for polymers stored at 0 °C.
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Affiliation(s)
- Maggie J. Malone-Povolny
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina, 27599, United States
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, CB3290, Chapel Hill, North Carolina, 27599, United States
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13
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Forlenza GP, Kushner T, Messer LH, Wadwa RP, Sankaranarayanan S. Factory-Calibrated Continuous Glucose Monitoring: How and Why It Works, and the Dangers of Reuse Beyond Approved Duration of Wear. Diabetes Technol Ther 2019; 21:222-229. [PMID: 30817171 PMCID: PMC6477582 DOI: 10.1089/dia.2018.0401] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Continuous glucose monitors (CGM) display real-time glucose values enabling greater glycemic awareness with reduced management burden. Factory-calibrated CGM systems allow for glycemic assessment without the pain and inconvenience of fingerstick glucose testing. Advances in sensor chemistry and CGM algorithms have enabled factory-calibrated systems to have greater accuracy than previous generations of CGM technology. Despite these advances many patients and providers are hesitant about the idea of removing fingerstick testing from their diabetes care. In this commentary, we aim to review the clinical trials on factory-calibrated CGM systems, present the algorithms which facilitate factory-calibrated CGMs to improve accuracy, discuss clinical use of factory-calibrated CGMs, and finally present two cases demonstrating the dangers of utilizing exploits in commercial systems to prolong sensor life.
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Affiliation(s)
- Gregory P. Forlenza
- Department of Pediatric Endocrinology, Barbara Davis Center, University of Colorado Denver, Aurora, Colorado
- Address correspondence to: Gregory P. Forlenza, MD, Department of Pediatric Endocrinology, Barbara Davis Center, University of Colorado Denver, 1775 Aurora CT, MS A140, Aurora, CO 80045
| | - Taisa Kushner
- Department of Computer Science, University of Colorado, Boulder, Colorado
| | - Laurel H. Messer
- Department of Pediatric Endocrinology, Barbara Davis Center, University of Colorado Denver, Aurora, Colorado
| | - R. Paul Wadwa
- Department of Pediatric Endocrinology, Barbara Davis Center, University of Colorado Denver, Aurora, Colorado
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14
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Ernst AU, Bowers DT, Wang LH, Shariati K, Plesser MD, Brown NK, Mehrabyan T, Ma M. Nanotechnology in cell replacement therapies for type 1 diabetes. Adv Drug Deliv Rev 2019; 139:116-138. [PMID: 30716349 PMCID: PMC6677642 DOI: 10.1016/j.addr.2019.01.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2018] [Revised: 01/17/2019] [Accepted: 01/28/2019] [Indexed: 12/12/2022]
Abstract
Islet transplantation is a promising long-term, compliance-free, complication-preventing treatment for type 1 diabetes. However, islet transplantation is currently limited to a narrow set of patients due to the shortage of donor islets and side effects from immunosuppression. Encapsulating cells in an immunoisolating membrane can allow for their transplantation without the need for immunosuppression. Alternatively, "open" systems may improve islet health and function by allowing vascular ingrowth at clinically attractive sites. Many processes that enable graft success in both approaches occur at the nanoscale level-in this review we thus consider nanotechnology in cell replacement therapies for type 1 diabetes. A variety of biomaterial-based strategies at the nanometer range have emerged to promote immune-isolation or modulation, proangiogenic, or insulinotropic effects. Additionally, coating islets with nano-thin polymer films has burgeoned as an islet protection modality. Materials approaches that utilize nanoscale features manipulate biology at the molecular scale, offering unique solutions to the enduring challenges of islet transplantation.
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Affiliation(s)
- Alexander U Ernst
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Daniel T Bowers
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Long-Hai Wang
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Kaavian Shariati
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Mitchell D Plesser
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Natalie K Brown
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Tigran Mehrabyan
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Minglin Ma
- Department of Biological and Environmental Engineering, Cornell University, Ithaca, NY 14853, USA.
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15
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Heo JC, Kim B, Kim YN, Kim DK, Lee JH. Induction of Inflammation In Vivo by Electrocardiogram Sensor Operation Using Wireless Power Transmission. SENSORS 2017; 17:s17122905. [PMID: 29240666 PMCID: PMC5751571 DOI: 10.3390/s17122905] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 12/08/2017] [Accepted: 12/12/2017] [Indexed: 12/04/2022]
Abstract
Prolonged monitoring by cardiac electrocardiogram (ECG) sensors is useful for patients with emergency heart conditions. However, implant monitoring systems are limited by lack of tissue biocompatibility. Here, we developed an implantable ECG sensor for real-time monitoring of ventricular fibrillation and evaluated its biocompatibility using an animal model. The implantable sensor comprised transplant sensors with two electrodes, a wireless power transmission system, and a monitoring system. The sensor was inserted into the subcutaneous tissue of the abdominal area and operated for 1 h/day for 5 days using a wireless power system. Importantly, the sensor was encapsulated by subcutaneous tissue and induced angiogenesis, inflammation, and phagocytosis. In addition, we observed that the levels of inflammation-related markers increased with wireless-powered transmission via the ECG sensor; in particular, levels of the Th-1 cytokine interleukin-12 were significantly increased. The results showed that induced tissue damage was associated with the use of wireless-powered sensors. We also investigated research strategies for the prevention of adverse effects caused by lack of tissue biocompatibility of a wireless-powered ECG monitoring system and provided information on the clinical applications of inflammatory reactions in implant treatment using the wireless-powered transmission system.
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Affiliation(s)
- Jin-Chul Heo
- Department of Biomedical Engineering, School of Medicine, Keimyung University, Daegu 42601, Korea.
| | - Beomjoon Kim
- Department of Electronic and Electrical Engineering, School of Engineering, Keimyung University, Daegu 42601, Korea.
| | - Yoon-Nyun Kim
- Department of Internal Medicine, Dongsan Medical Center, Keimyung University, Daegu 41931, Korea.
| | - Dae-Kwang Kim
- Department of Medical Genetics, Hanvit Institution for Medical Genetics, Keimyung University, Daegu 42601, Korea.
| | - Jong-Ha Lee
- Department of Biomedical Engineering, School of Medicine, Keimyung University, Daegu 42601, Korea.
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16
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Cha KH, Wang X, Meyerhoff ME. Nitric Oxide Release for Improving Performance of Implantable Chemical Sensors - A Review. APPLIED MATERIALS TODAY 2017; 9:589-597. [PMID: 29520370 PMCID: PMC5837052 DOI: 10.1016/j.apmt.2017.10.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Over the last three decades, there has been extensive interest in developing in vivo chemical sensors that can provide real-time measurements of blood gases (oxygen, carbon dioxide, and pH), glucose/lactate, and potentially other critical care analytes in the blood of hospitalized patients. However, clot formation with intravascular sensors and foreign body response toward sensors implanted subcutaneously can cause inaccurate analytical results. Further, the risk of bacterial infection from any sensor implanted in the human body is another major concern. To solve these issues, the release of an endogenous gas molecule, nitric oxide (NO), from the surface of such sensors has been investigated owing to NO's ability to inhibit platelet activation/adhesion, foreign body response and bacterial growth. This paper summarizes the importance of NO's therapeutic potential for this application and reviews the publications to date that report on the analytical performance of NO release sensors in laboratory testing and/or during in vivo testing.
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Affiliation(s)
- Kyoung Ha Cha
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109-1055, USA
| | - Xuewei Wang
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109-1055, USA
| | - Mark E Meyerhoff
- Department of Chemistry, University of Michigan, 930 N. University Ave., Ann Arbor, MI 48109-1055, USA
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17
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Buzzacchera I, Vorobii M, Kostina NY, de Los Santos Pereira A, Riedel T, Bruns M, Ogieglo W, Möller M, Wilson CJ, Rodriguez-Emmenegger C. Polymer Brush-Functionalized Chitosan Hydrogels as Antifouling Implant Coatings. Biomacromolecules 2017; 18:1983-1992. [PMID: 28475307 DOI: 10.1021/acs.biomac.7b00516] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Implantable sensor devices require coatings that efficiently interface with the tissue environment to mediate biochemical analysis. In this regard, bioinspired polymer hydrogels offer an attractive and abundant source of coating materials. However, upon implantation these materials generally elicit inflammation and the foreign body reaction as a consequence of protein fouling on their surface and concomitant poor hemocompatibility. In this report we investigate a strategy to endow chitosan hydrogel coatings with antifouling properties by the grafting of polymer brushes in a "grafting-from" approach. Chitosan coatings were functionalized with polymer brushes of oligo(ethylene glycol) methyl ether methacrylate and 2-hydroxyethyl methacrylate using photoinduced single electron transfer living radical polymerization and the surfaces were thoroughly characterized by XPS, AFM, water contact angle goniometry, and in situ ellipsometry. The antifouling properties of these new bioinspired hydrogel-brush coatings were investigated by surface plasmon resonance. The influence of the modifications to the chitosan on hemocompatibility was assessed by contacting the surfaces with platelets and leukocytes. The coatings were hydrophilic and reached a thickness of up to 180 nm within 30 min of polymerization. The functionalization of the surface with polymer brushes significantly reduced the protein fouling and eliminated platelet activation and leukocyte adhesion. This methodology offers a facile route to functionalizing implantable sensor systems with antifouling coatings that improve hemocompatibility and pave the way for enhanced device integration in tissue.
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Affiliation(s)
| | - Mariia Vorobii
- DWI-Leibniz Institute for Interactive Materials and Institute of Technical and Macromolecular Chemistry, RWTH Aachen University , Forckenbeckstraße 50, 52074 Aachen, Germany
| | - Nina Yu Kostina
- DWI-Leibniz Institute for Interactive Materials and Institute of Technical and Macromolecular Chemistry, RWTH Aachen University , Forckenbeckstraße 50, 52074 Aachen, Germany
| | - Andres de Los Santos Pereira
- Department of Chemistry and Physics of Surfaces and Biointerfaces, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , v.v.i., Heyrovsky Square 2, 16206 Prague, Czech Republic
| | - Tomáš Riedel
- Department of Chemistry and Physics of Surfaces and Biointerfaces, Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic , v.v.i., Heyrovsky Square 2, 16206 Prague, Czech Republic
| | - Michael Bruns
- Institute for Applied Materials (IAM) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT) , Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - Wojciech Ogieglo
- DWI-Leibniz Institute for Interactive Materials and Institute of Technical and Macromolecular Chemistry, RWTH Aachen University , Forckenbeckstraße 50, 52074 Aachen, Germany
| | - Martin Möller
- DWI-Leibniz Institute for Interactive Materials and Institute of Technical and Macromolecular Chemistry, RWTH Aachen University , Forckenbeckstraße 50, 52074 Aachen, Germany
| | | | - Cesar Rodriguez-Emmenegger
- DWI-Leibniz Institute for Interactive Materials and Institute of Technical and Macromolecular Chemistry, RWTH Aachen University , Forckenbeckstraße 50, 52074 Aachen, Germany
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18
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Soto RJ, Schofield JB, Walter SE, Malone-Povolny MJ, Schoenfisch MH. Design Considerations for Silica-Particle-Doped Nitric-Oxide-Releasing Polyurethane Glucose Biosensor Membranes. ACS Sens 2017; 2:140-150. [PMID: 28722434 PMCID: PMC6773259 DOI: 10.1021/acssensors.6b00623] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Nitric oxide (NO)-releasing polymers have proven useful for improving the biocompatibility of in vivo glucose biosensors. Unfortunately, leaching of the NO donor from the polymer matrix remains a critical design flaw of NO-releasing membranes. Herein, a toolbox of NO-releasing silica nanoparticles (SNPs) was utilized to systematically evaluate SNP leaching from a diverse selection of biomedical-grade polyurethane sensor membranes. Glucose sensor analytical performance and NO-release kinetics from the sensor membranes were also evaluated as a function of particle and polyurethane (PU) chemistries. Particles modified with N-diazeniumdiolate NO donors were prone to leaching from PU membranes due to the zwitterionic nature of the NO donor modification. Leaching was minimized (<5% of the entrapped silica over 1 month) in low water uptake PUs. However, SNP modification with neutral S-nitrosothiol (RSNO) NO donors lead to biphasic leaching behavior. Particles with low alkanethiol content (<3.0 wt % sulfur) leached excessively from a hydrogel PU formulation (HP-93A-100 PU), while particles with greater degrees of thiol modification did not leach from any of the PUs tested. A functional glucose sensor was developed using an optimized HP-93A-100 PU membrane doped with RSNO-modified SNPs as the outer, glucose diffusion-limiting layer. The realized sensor design responded linearly to physiological concentrations of glucose (minimum 1-21 mM) over 2 weeks incubation in PBS and released NO at >0.8 pmol cm-2 s-1 for up to 6 days with no detectable (<0.6%) particle leaching.
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Affiliation(s)
- Robert J. Soto
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jonathon B. Schofield
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Shaylyn E. Walter
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Maggie J. Malone-Povolny
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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19
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Benko A, Frączek-Szczypta A, Menaszek E, Wyrwa J, Nocuń M, Błażewicz M. On the influence of various physicochemical properties of the CNTs based implantable devices on the fibroblasts' reaction in vitro. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2015; 26:262. [PMID: 26464119 PMCID: PMC4604508 DOI: 10.1007/s10856-015-5597-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Accepted: 10/01/2015] [Indexed: 06/04/2023]
Abstract
Coating the material with a layer of carbon nanotubes (CNTs) has been a subject of particular interest for the development of new biomaterials. Such coatings, made of properly selected CNTs, may constitute an implantable electronic device that facilitates tissue regeneration both by specific surface properties and an ability to electrically stimulate the cells. The goal of the presented study was to produce, evaluate physicochemical properties and test the applicability of highly conductible material designed as an implantable electronic device. Two types of CNTs with varying level of oxidation were chosen. The process of coating involved suspension of the material of choice in the diluent followed by the electrophoretic deposition to fabricate layers on the surface of a highly biocompatible metal-titanium. Presented study includes an assessment of the physicochemical properties of the material's surface along with an electrochemical evaluation and in vitro biocompatibility, cytotoxicity and apoptosis studies in contact with the murine fibroblasts (L929) in attempt to answer the question how the chemical composition and CNTs distribution in the layer alters the electrical properties of the sample and whether any of these properties have influenced the overall biocompatibility and stimulated adhesion of fibroblasts. The results indicate that higher level of oxidation of CNTs yielded materials more conductive than the metal they are deposited on. In vitro study revealed that both materials were biocompatible and that the cells were not affected by the amount of the functional group and the morphology of the surface they adhered to.
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Affiliation(s)
- Aleksandra Benko
- AGH University of Science and Technology, Faculty of Materials Science and Ceramics, 30 Mickiewicza Ave., Kraków, 30-059, Poland.
| | - Aneta Frączek-Szczypta
- AGH University of Science and Technology, Faculty of Materials Science and Ceramics, 30 Mickiewicza Ave., Kraków, 30-059, Poland
| | - Elżbieta Menaszek
- Department of Cytobiology, Collegium Medicum, Jagiellonian University, 9 Medyczna St., 30-068, Kraków, Poland
| | - Jan Wyrwa
- AGH University of Science and Technology, Faculty of Materials Science and Ceramics, 30 Mickiewicza Ave., Kraków, 30-059, Poland
| | - Marek Nocuń
- AGH University of Science and Technology, Faculty of Materials Science and Ceramics, 30 Mickiewicza Ave., Kraków, 30-059, Poland
| | - Marta Błażewicz
- AGH University of Science and Technology, Faculty of Materials Science and Ceramics, 30 Mickiewicza Ave., Kraków, 30-059, Poland
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20
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Bachhuka A, Hayball J, Smith LE, Vasilev K. Effect of Surface Chemical Functionalities on Collagen Deposition by Primary Human Dermal Fibroblasts. ACS APPLIED MATERIALS & INTERFACES 2015; 7:23767-23775. [PMID: 26457649 DOI: 10.1021/acsami.5b08249] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Surface modification has been identified as an important technique that could improve the response of the body to implanted medical devices. Collagen production by fibroblasts is known to play a vital role in wound healing and device fibrous encapsulation. However, how surface chemistry affects collagen I and III deposition by these cells has not been systematically studied. Here, we report how surface chemistry influences the deposition of collagen I and III by primary human dermal fibroblasts. Amine (NH3), carboxyl acid (COOH), and hydrocarbon (CH3) surfaces were generated by plasma deposition. This is a practically relevant tool to deposit a functional coating on any type of substrate material. We show that fibroblasts adhere better and proliferate faster on amine-rich surfaces. In addition, the initial collagen I and III production is greater on this type of coating. These data indicates that surface modification can be a promising route for modulating the rate and level of fibrous encapsulation and may be useful in informing the design of implantable biomedical devices to produce more predictable clinical outcomes.
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Affiliation(s)
| | - John Hayball
- Experimental Therapeutics Laboratory, Sansom Institute and Hanson Institute, School of Pharmacy and Medical Science, University of South Australia , Adelaide, South Australia 5000, Australia
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21
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Cordeiro C, de Vries M, Ngabi W, Oomen P, Cremers T, Westerink B. In vivo continuous and simultaneous monitoring of brain energy substrates with a multiplex amperometric enzyme-based biosensor device. Biosens Bioelectron 2015; 67:677-86. [DOI: 10.1016/j.bios.2014.09.101] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Revised: 08/27/2014] [Accepted: 09/22/2014] [Indexed: 01/30/2023]
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22
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Shah VN, Shoskes A, Tawfik B, Garg SK. Closed-loop system in the management of diabetes: past, present, and future. Diabetes Technol Ther 2014; 16:477-90. [PMID: 25072271 DOI: 10.1089/dia.2014.0193] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Intensive insulin therapy (IIT) has been shown to reduce micro- and macrovascular complications in patients with type 1 diabetes mellitus (T1DM). However, IIT is associated with a significant increase in severe hypoglycemic events, resulting in increased morbidity and mortality. Optimization of glycemic control without hypoglycemia (especially nocturnal) should be the next major goal for subjects on insulin treatment. The use of insulin pumps along with continuous glucose monitors (CGMs) has made it easier but requires significant resources and patient education. Research is ongoing to close the loop by integrating the pump and the CGM using different algorithms. The currently available closed-loop system is the threshold suspend. Steps needed to achieve a near-perfect closed-loop are (1) a control-to-range system that will reduce the incidence and/or severity of hyper- and/or hypoglycemia by adjusting the insulin dose and (2) a control-to-target system, a fully automated or hybrid system that sets target glucose levels to individual needs and maintains glucose levels throughout the day using insulin (unihormonal) alone or with other hormones such as glucagon or possibly pramlintide (bihormonal). Future research is also focusing on better insulin delivery devices (pumps), more accurate CGMs, better predictive algorithms, and ultra-rapid-acting insulin analogs to make the closed-loop system as physiological as possible.
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Affiliation(s)
- Viral N Shah
- 1 Barbara Davis Center for Diabetes, University of Colorado Denver , Aurora, Colorado
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23
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Soto R, Privett BJ, Schoenfisch MH. In vivo analytical performance of nitric oxide-releasing glucose biosensors. Anal Chem 2014; 86:7141-9. [PMID: 24984031 PMCID: PMC4116185 DOI: 10.1021/ac5017425] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Accepted: 06/20/2014] [Indexed: 01/05/2023]
Abstract
The in vivo analytical performance of percutaneously implanted nitric oxide (NO)-releasing amperometric glucose biosensors was evaluated in swine for 10 d. Needle-type glucose biosensors were functionalized with NO-releasing polyurethane coatings designed to release similar total amounts of NO (3.1 μmol cm(-2)) for rapid (16.0 ± 4.4 h) or slower (>74.6 ± 16.6 h) durations and remain functional as outer glucose sensor membranes. Relative to controls, NO-releasing sensors were characterized with improved numerical accuracy on days 1 and 3. Furthermore, the clinical accuracy and sensitivity of rapid NO-releasing sensors were superior to control and slower NO-releasing sensors at both 1 and 3 d implantation. In contrast, the slower, extended, NO-releasing sensors were characterized by shorter sensor lag times (<4.2 min) in response to intravenous glucose tolerance tests versus burst NO-releasing and control sensors (>5.8 min) at 3, 7, and 10 d. Collectively, these results highlight the potential for NO release to enhance the analytical utility of in vivo glucose biosensors. Initial results also suggest that this analytical performance benefit is dependent on the NO-release duration.
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Affiliation(s)
- Robert
J. Soto
- Department
of Chemistry, University of North Carolina
at Chapel Hill, CB 3290, Chapel Hill, North Carolina 27599, United States
| | - Benjamin J. Privett
- Novan
Therapeutics, 4222 Emperor
Boulevard, Suite 200, Durham, North Carolina 27703, United States
| | - Mark H. Schoenfisch
- Department
of Chemistry, University of North Carolina
at Chapel Hill, CB 3290, Chapel Hill, North Carolina 27599, United States
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24
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Cell based metabolic barriers to glucose diffusion: macrophages and continuous glucose monitoring. Biomaterials 2014; 35:3145-53. [PMID: 24461328 DOI: 10.1016/j.biomaterials.2014.01.001] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Accepted: 01/01/2014] [Indexed: 12/27/2022]
Abstract
It is assumed that MQ are central to glucose sensor bio-fouling and therefore have a major negative impact on continuous glucose monitoring (CGM) performance in vivo. However to our knowledge there is no data in the literature to directly support or refute this assumption. Since glucose and oxygen (O2) are key to glucose sensor function in vivo, understanding and controlling glucose and O2 metabolic activity of MQ is likely key to successful glucose sensor performance. We hypothesized that the accumulation of MQ at the glucose sensor-tissue interface will act as "Cell Based Metabolic Barriers" (CBMB) to glucose diffusing from the interstitial tissue compartment to the implanted glucose sensor and as such creating an artificially low sensor output, thereby compromising sensor function and CGM. Our studies demonstrated that 1) direct injections of MQ at in vivo sensor implantation sites dramatically decreased sensor output (measured in nA), 2) addition of MQ to glucose sensors in vitro resulted in a rapid and dramatic fall in sensor output and 3) lymphocytes did not affect sensor function in vitro or in vivo. These data support our hypothesis that MQ can act as metabolic barriers to glucose and O2 diffusion in vivo and in vitro.
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25
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Koh A, Lu Y, Schoenfisch MH. Fabrication of nitric oxide-releasing porous polyurethane membranes-coated needle-type implantable glucose biosensors. Anal Chem 2013; 85:10488-94. [PMID: 24102638 DOI: 10.1021/ac402312b] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The active release of pharmaceutical agents and the use of porous sensor membranes represent the two most promising strategies for addressing the poor tissue biocompatibility of implantable glucose biosensors. Herein, we describe the combination of these approaches to create nitric oxide (NO)-releasing porous fiber mat-modified sensor membranes. An electrospinning method was used to directly modify needle-type glucose biosensors with the NO donor-loaded fibers. The resulting NO-releasing fiber mat (540 ± 139 nm fiber diameter, 94.1 ± 3.7% porosity) released ~100 nmol of NO per mg of polyurethane over 6 h while maintaining a porous structure without leaching of the NO donor, even in serum. The porous fiber membrane did not influence the analytical performance of the biosensor when ≤50 μm thick.
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Affiliation(s)
- Ahyeon Koh
- Department of Chemistry, The University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
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Felice AKG, Sygmund C, Harreither W, Kittl R, Gorton L, Ludwig R. Substrate specificity and interferences of a direct-electron-transfer-based glucose biosensor. J Diabetes Sci Technol 2013; 7:669-77. [PMID: 23759400 PMCID: PMC3869135 DOI: 10.1177/193229681300700312] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Electrochemical sensors for glucose monitoring employ different signal transduction strategies for electron transfer from the biorecognition element to the electrode surface. We present a biosensor that employs direct electron transfer and evaluate its response to various interfering substances known to affect glucose biosensors. METHODS The enzyme cellobiose dehydrogenase (CDH) was adsorbed on the surface of a carbon working electrode and covalently bound by cross linking. The response of CDH-modified electrodes to glucose and possible interfering compounds was measured by flow-injection analysis, linear sweep, and chronoamperometry. RESULTS Chronoamperometry showed initial swelling/wetting of the electrode. After stabilization, the signal was stable and a sensitivity of 0.21 µA mM-1 cm-2 was obtained. To investigate the influence of the interfering substances on the biorecognition element, the simplest possible sensor architecture was used. The biosensor showed little (<5% signal deviation) or no response to various reported electroactive or otherwise interfering substances. CONCLUSIONS Direct electron transfer from the biorecognition element to the electrode is a new principle applied to glucose biosensors, which can be operated at a low polarization potential of -100 mV versus silver/silver chloride. The reduction of interferences by electrochemically active substances is an attractive feature of this promising technology for the development of continuous glucose biosensors.
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Affiliation(s)
- Alfons K. G. Felice
- Department of Food Science and Technology, Vienna Institute of Biotechnology, BOKU—University of Natural Resources and Life Sciences, Vienna, Austria
| | | | | | - Roman Kittl
- Department of Food Science and Technology, Vienna Institute of Biotechnology, BOKU—University of Natural Resources and Life Sciences, Vienna, Austria
- DirectSens GmbH, Klosterneuburg, Austria
| | - Lo Gorton
- Department of Analytical Chemistry, Biochemistry and Structural Biology, Lund University Lund, Sweden
| | - Roland Ludwig
- Department of Food Science and Technology, Vienna Institute of Biotechnology, BOKU—University of Natural Resources and Life Sciences, Vienna, Austria
- DirectSens GmbH, Klosterneuburg, Austria
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Nichols SP, Koh A, Storm WL, Shin JH, Schoenfisch MH. Biocompatible materials for continuous glucose monitoring devices. Chem Rev 2013; 113:2528-49. [PMID: 23387395 PMCID: PMC3624030 DOI: 10.1021/cr300387j] [Citation(s) in RCA: 188] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Affiliation(s)
- Scott P. Nichols
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Ahyeon Koh
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Wesley L. Storm
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Jae Ho Shin
- Department of Chemistry, Kwangwoon University, Seoul, Korea
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Lane JE, Shivers JP, Zisser H. Continuous glucose monitors: current status and future developments. Curr Opin Endocrinol Diabetes Obes 2013; 20:106-11. [PMID: 23422244 DOI: 10.1097/med.0b013e32835edb9d] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
PURPOSE OF REVIEW Advances in diabetes technologies allow patients to manage their diabetes with greater precision and flexibility. Many recent studies show that continuous glucose monitors (CGMs) can be used to tighten glycemic control safely and to ease certain burdens of diabetes self-management. RECENT FINDINGS The following summary reflects the most recent findings in CGM and provides an overall review of who would most benefit from CGM use. Benefits of CGM may vary based on age, type of diabetes, pregnancy, health, sleep, or heart rate. Accuracy and reliability are critical in current uses of CGM and especially for new and future systems that automate insulin partially (e.g., low glucose suspend) or entirely (e.g., 'fully closed-loop' artificial pancreas). Clinicians are simultaneously testing available products in new patient groups such as the critically ill and type 2 diabetes patients not using mealtime insulin. SUMMARY In a widening set of circumstances, use of CGM has been shown to promote safer and more effective glycemic control than self-monitoring of blood glucose. Imperfections remain in certain scenarios such as hypoglycemia and in certain populations such as young children. Ongoing research on sensors and calibration software should translate to better systems.
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Affiliation(s)
- Jennifer E Lane
- Sansum Diabetes Research Institute, Santa Barbara, California, USA
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Vaddiraju S, Legassey A, Qiang L, Wang Y, Burgess DJ, Papadimitrakopoulos F. Enhancing the sensitivity of needle-implantable electrochemical glucose sensors via surface rebuilding. J Diabetes Sci Technol 2013; 7:441-51. [PMID: 23567003 PMCID: PMC3737646 DOI: 10.1177/193229681300700221] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Needle-implantable sensors have shown to provide reliable continuous glucose monitoring for diabetes management. In order to reduce tissue injury during sensor implantation, there is a constant need for device size reduction, which imposes challenges in terms of sensitivity and reliability, as part of decreasing signal-to-noise and increasing layer complexity. Herein, we report sensitivity enhancement via electrochemical surface rebuilding of the working electrode (WE), which creates a three-dimensional nanoporous configuration with increased surface area. METHODS The gold WE was electrochemically rebuilt to render its surface nanoporous followed by decoration with platinum nanoparticles. The efficacy of such process was studied using sensor sensitivity against hydrogen peroxide (H2O2). For glucose detection, the WE was further coated with five layers, namely, (1) polyphenol, (2) glucose oxidase, (3) polyurethane, (4) catalase, and (5) dexamethasone-releasing poly(vinyl alcohol)/poly(lactic-co-glycolic acid) composite. The amperometric response of the glucose sensor was noted in vitro and in vivo. RESULTS Scanning electron microscopy revealed that electrochemical rebuilding of the WE produced a nanoporous morphology that resulted in a 20-fold enhancement in H2O2 sensitivity, while retaining >98% selectivity. This afforded a 4-5-fold increase in overall glucose response of the glucose sensor when compared with a control sensor with no surface rebuilding and fittable only within an 18 G needle. The sensor was able to reproducibly track in vivo glycemic events, despite the large background currents typically encountered during animal testing. CONCLUSION Enhanced sensor performance in terms of sensitivity and large signal-to-noise ratio has been attained via electrochemical rebuilding of the WE. This approach also bypasses the need for conventional and nanostructured mediators currently employed to enhance sensor performance.
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Affiliation(s)
- Santhisagar Vaddiraju
- Biorasis Inc. Technology Incubation Program, University of Connecticut, Storrs, Connecticut
- Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, Connecticut
| | - Allen Legassey
- Biorasis Inc. Technology Incubation Program, University of Connecticut, Storrs, Connecticut
| | - Liangliang Qiang
- Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, Connecticut
| | - Yan Wang
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut
| | - Diane J. Burgess
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, Connecticut
| | - Fotios Papadimitrakopoulos
- Biorasis Inc. Technology Incubation Program, University of Connecticut, Storrs, Connecticut
- Department of Chemistry, University of Connecticut, Storrs, Connecticut
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Vaddiraju S, Wang Y, Qiang L, Burgess DJ, Papadimitrakopoulos F. Microsphere erosion in outer hydrogel membranes creating macroscopic porosity to counter biofouling-induced sensor degradation. Anal Chem 2012; 84:8837-8845. [PMID: 23039161 PMCID: PMC3791326 DOI: 10.1021/ac3022423] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Biofouling and tissue inflammation present major challenges toward the realization of long-term implantable glucose sensors. Following sensor implantation, proteins and cells adsorb on sensor surfaces to not only inhibit glucose flux but also signal a cascade of inflammatory events that eventually lead to permeability-reducing fibrotic encapsulation. The use of drug-eluting hydrogels as outer sensor coatings has shown considerable promise to mitigate these problems via the localized delivery of tissue response modifiers to suppress inflammation and fibrosis, along with reducing protein and cell absorption. Biodegradable poly (lactic-co-glycolic) acid (PLGA) microspheres, encapsulated within a poly (vinyl alcohol) (PVA) hydrogel matrix, present a model coating where the localized delivery of the potent anti-inflammatory drug dexamethasone has been shown to suppress inflammation over a period of 1-3 months. Here, it is shown that the degradation of the PLGA microspheres provides an auxiliary venue to offset the negative effects of protein adsorption. This was realized by: (1) the creation of fresh porosity within the PVA hydrogel following microsphere degradation (which is sustained until the complete microsphere degradation) and (2) rigidification of the PVA hydrogel to prevent its complete collapse onto the newly created void space. Incubation of the coated sensors in phosphate buffered saline (PBS) led to a monotonic increase in glucose permeability (50%), with a corresponding enhancement in sensor sensitivity over a 1 month period. Incubation in serum resulted in biofouling and consequent clogging of the hydrogel microporosity. This, however, was partially offset by the generated macroscopic porosity following microsphere degradation. As a result of this, a 2-fold recovery in sensor sensitivity for devices with microsphere/hydrogel composite coatings was observed as opposed to similar devices with blank hydrogel coatings. These findings suggest that the use of macroscopic porosity can reduce sensitivity drifts resulting from biofouling, and this can be achieved synergistically with current efforts to mitigate negative tissue responses through localized and sustained drug delivery.
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Affiliation(s)
- S. Vaddiraju
- Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136
- Biorasis Inc. Technology Incubation Program, University of Connecticut, Storrs, CT 06269-4213
| | - Y. Wang
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092
| | - L. Qiang
- Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136
| | - D. J. Burgess
- Department of Pharmaceutical Sciences, University of Connecticut, Storrs, CT 06269-3092
| | - F. Papadimitrakopoulos
- Polymer Program, Institute of Materials Science, University of Connecticut, Storrs, CT 06269-3136
- Department of Chemistry, University of Connecticut, Storrs, CT 06269-3060
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Nichols SP, Koh A, Brown NL, Rose MB, Sun B, Slomberg DL, Riccio DA, Klitzman B, Schoenfisch MH. The effect of nitric oxide surface flux on the foreign body response to subcutaneous implants. Biomaterials 2012; 33:6305-12. [PMID: 22748919 PMCID: PMC3667553 DOI: 10.1016/j.biomaterials.2012.05.053] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Accepted: 05/20/2012] [Indexed: 01/09/2023]
Abstract
Although the release of nitric oxide (NO) from biomaterials has been shown to reduce the foreign body response (FBR), the optimal NO release kinetics and doses remain unknown. Herein, polyurethane-coated wire substrates with varying NO release properties were implanted into porcine subcutaneous tissue for 3, 7, 21 and 42 d. Histological analysis revealed that materials with short NO release durations (i.e., 24 h) were insufficient to reduce the collagen capsule thickness at 3 and 6 weeks, whereas implants with longer release durations (i.e., 3 and 14 d) and greater NO payloads significantly reduced the collagen encapsulation at both 3 and 6 weeks. The acute inflammatory response was mitigated most notably by systems with the longest duration and greatest dose of NO release, supporting the notion that these properties are most critical in circumventing the FBR for subcutaneous biomedical applications (e.g., glucose sensors).
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Affiliation(s)
- Scott P. Nichols
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ahyeon Koh
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nga L. Brown
- Kenan Plastic Surgery Research Laboratories, Department of Biomedical Engineering, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael B. Rose
- Kenan Plastic Surgery Research Laboratories, Department of Biomedical Engineering, Duke University Medical Center, Durham, NC 27710, USA
| | - Bin Sun
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Danielle L. Slomberg
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Daniel A. Riccio
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Bruce Klitzman
- Kenan Plastic Surgery Research Laboratories, Department of Biomedical Engineering, Duke University Medical Center, Durham, NC 27710, USA
| | - Mark H. Schoenfisch
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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