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Hsiao CY, Yang SC, Alalaiwe A, Fang JY. Laser ablation and topical drug delivery: a review of recent advances. Expert Opin Drug Deliv 2019; 16:937-952. [DOI: 10.1080/17425247.2019.1649655] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Chien-Yu Hsiao
- Department of Nutrition and Health Sciences, Chang Gung University of Science and Technology, Taoyuan, Taiwan
- Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Taoyuan, Taiwan
- Aesthetic Medical Center, Department of Dermatology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Shih-Chun Yang
- Department of Cosmetic Science, Providence University, Taichung, Taiwan
| | - Ahmed Alalaiwe
- Department of Pharmaceutics, College of Pharmacy, Prince Sattam Bin Abdulaziz University, Al Kharj, Saudi Arabia
| | - Jia-You Fang
- Research Center for Food and Cosmetic Safety and Research Center for Chinese Herbal Medicine, Chang Gung University of Science and Technology, Taoyuan, Taiwan
- Pharmaceutics Laboratory, Graduate Institute of Natural Products, Chang Gung University, Taoyuan, Taiwan
- Department of Anesthesiology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
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2
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Ramaprasad V, Navarro A, Patel S, Patel V, Nowroozi BN, Taylor ZD, Yong W, Gupta V, Grundfest WS. Effect of laser generated shockwaves 1 on ex-vivo pigskin. Lasers Surg Med 2014; 46:620-7. [DOI: 10.1002/lsm.22278] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/08/2014] [Indexed: 01/12/2023]
Affiliation(s)
| | - Artemio Navarro
- University of California; Los Angeles; Los Angeles California 90095
| | - Shahzad Patel
- University of California; Los Angeles; Los Angeles California 90095
| | - Vikash Patel
- University of California; Los Angeles; Los Angeles California 90095
| | | | - Zach D. Taylor
- University of California; Los Angeles; Los Angeles California 90095
| | - William Yong
- University of California; Los Angeles; Los Angeles California 90095
| | - Vijay Gupta
- University of California; Los Angeles; Los Angeles California 90095
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3
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Terakawa M, Tsuda H, Ashida H, Sato S. Assessment of tissue alteration in skin after interaction with photomechanical waves used for gene transfection. Lasers Surg Med 2010; 42:400-7. [DOI: 10.1002/lsm.20928] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Stübinger S, von Rechenberg VB, Zeilhofer HF, Sader R, Landes C. Er:YAG laser osteotomy for removal of impacted teeth: Clinical comparison of two techniques. Lasers Surg Med 2007; 39:583-8. [PMID: 17868108 DOI: 10.1002/lsm.20528] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND AND OBJECTIVES In contrast to many techniques currently employed for osteotomy, like saws, drills or modulated ultrasound, lasers offer non-contact and low-vibration bone cutting. Therefore, this report examines the benefits to laser osteotomy in oral surgery using two different short-pulsed Er:YAG laser systems. MATERIALS AND METHODS Er:YAG lasers, using either a fiber-optic delivery system and an articulated arm delivery system, were used to remove impacted teeth in 30 patients. In 15 patients an Er:YAG laser utilizing a fiber-optic delivery system was applied for cutting bone, with a pulse energy of 500 mJ, a pulse duration of 250 microseconds and frequency of 12 Hz (energy density 177 J/cm(2)). The other 15 patients were treated with an Er:YAG laser utilizing an articulated arm delivery system, with a pulse energy of 1,000 mJ, a pulse duration of 300 microseconds and a frequency of 12 Hz (energy density 157 J/cm(2)). RESULTS In all cases the lasers allowed precise bone ablation without any visible, negative, thermal side-effects. Since the laser tip was used in a non-contact mode and could be positioned freely, unrestricted cut geometries were feasible. Adjacent soft tissue structures could be preserved and were not harmed by the laser beam. However, osteotomies were time consuming, especially if teeth had to be separated. The level of water irrigation limited the use of the laser. In 20% of the cases in which the articulated arm delivery laser was used to section teeth, it was necessary to use a conventional dental drill to finish the procedure. CONCLUSION This bone ablation technique, using short Er:YAG laser pulses and water spray, produced good clinical results without any impairment to wound healing. However, for now, the lack of depth control and the time required to perform the necessary osteotomy limit routine clinical application.
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Affiliation(s)
- Stefan Stübinger
- University Clinic for Reconstructive Surgery, Department of Cranio- and Maxillofacial Surgery, University Hospital Basel, Spitalstr 21, CH-4031, Basel, Switzerland.
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5
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Doukas AG, Kollias N. Transdermal drug delivery with a pressure wave. Adv Drug Deliv Rev 2004; 56:559-79. [PMID: 15019746 DOI: 10.1016/j.addr.2003.10.031] [Citation(s) in RCA: 157] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2003] [Accepted: 10/13/2003] [Indexed: 12/01/2022]
Abstract
Pressure waves, which are generated by intense laser radiation, can permeabilize the stratum corneum (SC) as well as the cell membrane. These pressure waves are compression waves and thus exclude biological effects induced by cavitation. Their amplitude is in the hundreds of atmospheres (bar) while the duration is in the range of nanoseconds to a few microseconds. The pressure waves interact with cells and tissue in ways that are probably different from those of ultrasound. Furthermore, the interactions of the pressure waves with tissue are specific and depend on their characteristics, such as peak pressure, rise time and duration. A single pressure wave is sufficient to permeabilize the SC and allow the transport of macromolecules into the epidermis and dermis. In addition, drugs delivered into the epidermis can enter the vasculature and produce a systemic effect. For example, insulin delivered by pressure waves resulted in reducing the blood glucose level over many hours. The application of pressure waves does not cause any pain or discomfort and the barrier function of the SC always recovers.
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Affiliation(s)
- Apostolos G Doukas
- Department of Dermatology, Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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6
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Menon GK, Kollias N, Doukas AG. Ultrastructural evidence of stratum corneum permeabilization induced by photomechanical waves. J Invest Dermatol 2003; 121:104-9. [PMID: 12839570 DOI: 10.1046/j.1523-1747.2003.12302.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Photomechanical waves (high amplitude pressure transients generated by lasers) have been shown to permeabilize the stratum corneum in vivo and facilitate the transport of macromolecules into the viable epidermis. The permeabilization of the stratum corneum is transient and its barrier function recovers. Sites on the volar forearm of humans were exposed to photomechanical waves and biopsies were obtained immediately after the exposure and processed for electron microscopy. Electron microscopy showed an expansion of the lacunar spaces within the stratum corneum lipid bilayers but no changes in the organization of the secreted lamellar bodies at the stratum corneum-stratum granulosum boundary. The combination of photomechanical waves and sodium lauryl sulfate enhances the efficiency of transdermal delivery and delays the recovery of the barrier function of the stratum corneum. Electron microscopy from sites exposed to photomechanical waves and sodium lauryl sulfate showed that the lacunar spaces expanded significantly more and the secreted lamellar bodies also appeared to be altered. In either case, there were no changes in the papillary dermis. These observations support the hypothesis that the photomechanical waves induce the expansion of the lacunar spaces within the stratum corneum leading to the formation of transient channels.
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Affiliation(s)
- Gopinathan K Menon
- Global Research & Development, Avon Products, Inc., Suffern, New York 10901, USA.
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7
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Lin TYD, McAuliffe DJ, Michaud N, Zhang H, Lee S, Doukas AG, Flotte TJ. Nuclear transport by laser-induced pressure transients. Pharm Res 2003; 20:879-83. [PMID: 12817891 DOI: 10.1023/a:1023835219041] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
PURPOSE Control of the transport of molecules into the nucleus represents a key regulatory mechanism for differentiation, transformation, and signal transduction. Permeabilization of the nuclear envelope by physical methods can have applications in gene therapy. Laser-induced pressure transients can produce temporary aqueous pores analogous to those produced by electroporation and that the cells can survive this procedure. In this study, we examine the role of the pressure transients in creating similar pores in the nuclear envelope. METHODS The target human peripheral blood mononuclear cells in a 62 microM 72 kDa fluoresceinated dextran solution were exposed to the pressure transients generated by laser ablation. An in vitro fluorescence confocal microscope was used to visualize and quantify the fluoresceinated dextran in the cytoplasmic and nuclear compartments. RESULTS In contrast to electroporation, the pressure transients could deliver 72 kDa fluoresceinated dextrans, which are normally excluded by the nucleus, across the nuclear envelope into the nucleus. In addition to creating pores in the plasma membrane, temporary pores were also created in the nuclear envelope following exposure to pressure transients. CONCLUSION The production of temporary nuclear pores could provide a unique resource for drug-delivery and gene therapy.
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Affiliation(s)
- Tai-Yuan David Lin
- Wellman Laboratories of Photomedicine, Department of Photopathology and Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts 02114, USA
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Affiliation(s)
- Alfred Vogel
- Medical Laser Center Lübeck, Peter-Monnik-Weg 4, D-23562 Lübeck, Germany.
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Mordon S, Capon A, Creusy C, Fleurisse L, Buys B, Faucheux M, Servell P. In vivo experimental evaluation of skin remodeling by using an Er:Glass laser with contact cooling. Lasers Surg Med 2000; 27:1-9. [PMID: 10918287 DOI: 10.1002/1096-9101(2000)27:1<1::aid-lsm1>3.0.co;2-v] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND AND OBJECTIVE Selective dermal remodeling consists of inducing collagen tightening, neocollagen synthesis, or both, without damage to the overlying epidermis. This experimental study aimed to evaluate an Er:Glass laser emitting at 1.54 micrometer combined with contact cooling to target the upper dermis while protecting the epidermis. STUDY DESIGN/MATERIALS AND METHODS Male hairless rats were used for the study. Different fluences (26-30 J/cm(2)) by using single 3-ms pulse irradiation or pulse train irradiation (1.1 J, 3 Hz) and different cooling temperatures (+5 degrees C, 0 degrees C, -5 degrees C) were screened with clinical examination and histologic evaluation at 1, 3, and 7 days after laser irradiation. RESULTS The clinical effects were clearly dose and temperature cooling dependent. It seemed that single pulse irradiation led to epidermal whitening in most cases, whatever the cooling temperature. Conversely, pulse train irradiation showed reproducible epidermal preservation and confinement of the thermal damage into the dermis. New collagen synthesis was confirmed by a marked fibroblastic proliferation, detected in the lower dermis at day 3 and clearly seen in the upper dermis at day 7. CONCLUSION This new laser seems to be a promising new tool for the treatment of skin laxity, solar elastosis, facial rhytides, and mild reduction of wrinkles.
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Affiliation(s)
- S Mordon
- Inserm-EA2689-IFR 22, Lille University Hospital, Lille, France.
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Neuman KC, Chadd EH, Liou GF, Bergman K, Block SM. Characterization of photodamage to Escherichia coli in optical traps. Biophys J 1999; 77:2856-63. [PMID: 10545383 PMCID: PMC1300557 DOI: 10.1016/s0006-3495(99)77117-1] [Citation(s) in RCA: 336] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Optical tweezers (infrared laser-based optical traps) have emerged as a powerful tool in molecular and cell biology. However, their usefulness has been limited, particularly in vivo, by the potential for damage to specimens resulting from the trapping laser. Relatively little is known about the origin of this phenomenon. Here we employed a wavelength-tunable optical trap in which the microscope objective transmission was fully characterized throughout the near infrared, in conjunction with a sensitive, rotating bacterial cell assay. Single cells of Escherichia coli were tethered to a glass coverslip by means of a single flagellum: such cells rotate at rates proportional to their transmembrane proton potential (Manson et al.,1980. J. Mol. Biol. 138:541-561). Monitoring the rotation rates of cells subjected to laser illumination permits a rapid and quantitative measure of their metabolic state. Employing this assay, we characterized photodamage throughout the near-infrared region favored for optical trapping (790-1064 nm). The action spectrum for photodamage exhibits minima at 830 and 970 nm, and maxima at 870 and 930 nm. Damage was reduced to background levels under anaerobic conditions, implicating oxygen in the photodamage pathway. The intensity dependence for photodamage was linear, supporting a single-photon process. These findings may help guide the selection of lasers and experimental protocols best suited for optical trapping work.
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Affiliation(s)
- K C Neuman
- Department of Physics, Princeton University, Princeton, New Jersey 08544, USA
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Mietz H, Severin M, Seifert P, Esser P, Krieglstein GK. Acute corneal necrosis after excimer laser keratectomy for hyperopia. Ophthalmology 1999; 106:490-6. [PMID: 10080204 DOI: 10.1016/s0161-6420(99)90106-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
OBJECTIVE To describe a new, rare clinical complication after routine excimer laser photorefractive keratectomy to correct hyperopia. DESIGN Case report with clinicopathologic correlation. MAIN OUTCOME MEASURES Four weeks after treatment with excimer laser, a perforating keratoplasty was performed for persistent corneal opacities. The corneal button was examined using light and electron microscopy. Special immunohistochemical stains were used to detect apoptosis. RESULTS The patient developed corneal opacities, endothelial precipitates, and a fibrinous exudate in the anterior chamber after the laser treatment. The changes did not respond to therapy directed against bacteria, fungi, and Acanthamoeba. All examinations and special stains were negative for micro-organisms. By light microscopy, an anterior zone of corneal necrosis was present with a moderate amount of acute inflammatory cells. At the interface between necrotic and viable corneal stroma, keratocytes with typical features of apoptosis were detected by immunohistochemistry and electron microscopy. CONCLUSION This is the first full histopathologic report of a case of acute corneal necrosis with signs of apoptosis after excimer laser therapy of the cornea. Surgeons should be aware of this rare but potentially severe complication.
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Affiliation(s)
- H Mietz
- Department of Ophthalmology, University of Cologne, Koeln, Germany
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12
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Bryant GL, Davidson JM, Ossoff RH, Garrett CG, Reinisch L. Histologic study of oral mucosa wound healing: a comparison of a 6.0- to 6.8-micrometer pulsed laser and a carbon dioxide laser. Laryngoscope 1998; 108:13-7. [PMID: 9432060 DOI: 10.1097/00005537-199801000-00003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Incisional wound healing in the canine oral mucosa was histologically monitored at 3, 7, and 14 days after incision. Healing was compared from a scalpel, a carbon dioxide (CO2) laser at 10.6 microm, and the Vanderbilt free-electron laser tuned to 6.0, 6.45, and 6.8 microm. A significant delay in wound healing was observed when incisions were made with the CO2 laser, probably attributable to the excess thermal damage caused by the continuous-wave laser beam. When using the short pulsed, free-electron laser, a much smaller delay comparable to the scalpel wound healing was observed. This smaller delay tended to decrease with increasing tissue absorption. The results emphasize the greater importance of laser pulse duration rather than wavelength in relation to the subsequent wound healing.
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Affiliation(s)
- G L Bryant
- Department of Otolaryngology, Vanderbilt University Medical Center, Nashville, Tennessee 37232, USA
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Doukas AG, Flotte TJ. Physical characteristics and biological effects of laser-induced stress waves. ULTRASOUND IN MEDICINE & BIOLOGY 1996; 22:151-64. [PMID: 8735525 DOI: 10.1016/0301-5629(95)02026-8] [Citation(s) in RCA: 90] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Laser-induced stress waves can be generated by one of the following mechanisms: optical breakdown, ablation, or rapid heating of an absorbing medium. These three modes of laser interaction with matter allow the investigation of cellular and tissue responses to stress waves with different characteristics and under different conditions. The effects of stress waves on cells and tissues can be quite disparate. Stress waves can fracture tissue, kill cells, decrease cell viability and increase the permeability of the plasma membrane. They can induce deleterious effects during medical procedures of high power, short pulse lasers or, alternatively, may facilitate new therapeutic modalities, such as drug delivery and gene therapy. This review covers the generation of laser-induced stress waves and their effects on cell cultures and tissue.
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Affiliation(s)
- A G Doukas
- Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Department of Dermatology, Harvard Medical School, Boston 02114, USA
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Douki T, Lee S, Dorey K, Flotte TJ, Deutsch TF, Doukas AG. Stress-wave-induced injury to retinal pigment epithelium cells in vitro. Lasers Surg Med Suppl 1996; 19:249-59. [PMID: 8923421 DOI: 10.1002/(sici)1096-9101(1996)19:3<249::aid-lsm1>3.0.co;2-s] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND AND OBJECTIVE To determine the survival of in vitro retinal pigment epithelium (RPE) cells subjected to laser-generated stress transients (shock waves) and compare it to that of other cell lines. STUDY DESIGN/MATERIALS AND METHODS Normal and transformed human retinal pigment epithelium cell lines were used. The cells were imbedded in a gel to prevent motion and cavitation and located in a thin layer at the bottom of a pipette tube closed at one end by a polyimide film. Stress transients were generated by pulsed excimer laser (193 nm and 248 nm wavelength) ablation of the polyimide film. Cell survival, compared to that of unirradiated cells, was assessed by counting surviving cells. The stress was varied from 300 to 740 bars and the number of shock wave pulses applied varied from 5 to 150. RESULTS Cell survival decreased sharply at the higher stresses but some cells always survived. The lowest survival rate was 50%. Increasing the number of shock wave pulses did not increase cell killing after 20 pulses, demonstrating a saturation effect. In contrast to the transformed cell line, normal cells could not be killed at the highest stress available to us. CONCLUSION The susceptibility of RPE cells to damage by stress waves varies with cell line. Transformed retinal pigment epithelium cells are more susceptible than normal ones. Saturation of the damage versus number of pulses is observed and a threshold-like behavior for cell killing versus stress is found. Because at least 50% of the cells survived, normal cell growth can serve to replenish damaged cells.
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Affiliation(s)
- T Douki
- Wellman Laboratories of Photomedicine, Massachusetts General Hospital, Boston 02114, USA
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Venugopalan V, Nishioka NS, Mikić BB. The thermodynamic response of soft biological tissues to pulsed ultraviolet laser irradiation. Biophys J 1995; 69:1259-71. [PMID: 8534796 PMCID: PMC1236356 DOI: 10.1016/s0006-3495(95)80024-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The physical mechanisms that enable short pulses of high-intensity ultraviolet laser radiation to remove tissue, in a process known as laser ablation, remain obscure. The thermodynamic response of biological tissue to pulsed laser irradiation was investigated by measuring and subsequently analyzing the stress transients generated by pulsed argon fluorine (ArF, lambda = 193 nm) and krypton fluorine (KrF, lambda = 248 nm) excimer laser irradiation of porcine dermis using thin-film piezoelectric transducers. For radiant exposures that do not cause material removal, the stress transients are consistent with rapid thermal expansion of the tissue. At the threshold radiant exposure for ablation, the peak stress amplitude generated by 248 nm irradiation is more than an order of magnitude larger than that produced by 193 nm irradiation. For radiant exposures where material removal is achieved, the temporal structure of the stress transient indicates that the onset of material removal occurs during irradiation. In this regime, the variation of the peak compressive stress with radiant exposure is consistent with laser-induced rapid surface vaporization. For 193 nm irradiation, ionization of the ablated material occurs at even greater radiant exposures and is accompanied by a change in the variation of peak stress with radiant exposure consistent with a plasma-mediated ablation process. These results suggest that absorption of ultraviolet laser radiation by the extracellular matrix of tissue leads to decomposition of tissue on the time scale of the laser pulse. The difference in volumetric energy density at ablation threshold between the two wavelengths indicates that the larger stresses generated by 248 nm irradiation may facilitate the onset of material removal. However, once material removal is achieved, the stress measurements demonstrate that energy not directly responsible for target decomposition contributes to increasing the specific energy of the plume (and plasma, when present), which drives the gas dynamic expansion of ablated material. This provides direct evidence that ultraviolet laser ablation of soft biological tissues is a surface-mediated process and not explosive in nature.
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Affiliation(s)
- V Venugopalan
- Wellman Laboratories of Photomedicine, Harvard Medical School, Massachusetts General Hospital, Boston 02114, USA
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Abstract
The accessibility of the skin to examination and study has permitted dermatologists to play an extremely important role in defining the clinical usefulness and limitations of many laser systems as well as developing innovative concepts, techniques and devices that further improved the effectiveness of laser treatment. As new laser technology evolved over the years, dermatologists have also helped define the specificity of laser-tissue interaction and employed the newly developed laser technologies in innovative ways which further expanded the usefulness of these devices. One of the most important concepts to be developed by dermatologists--selective photothermolysis--has led to the creation of a series of laser systems which have provided numerous unique advantages in the management of many common vascular and pigmented conditions of the skin and mucous membranes, even in infants and children. The net result of these technologic advances has been the creation of new and effective treatment techniques which have been so profoundly superior to existing technology that they have been rapidly incorporated into the daily practice of most dermatologists.
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Affiliation(s)
- R G Wheeland
- Department of Dermatology, University of New Mexico, Albuquerque 87131, USA
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Prodoehl JA, Rhodes AL, Cummings RS, Meller MM, Sherk HH. 308 nm excimer laser ablation of cartilage. Lasers Surg Med Suppl 1994; 15:263-8. [PMID: 7830471 DOI: 10.1002/lsm.1900150305] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This article reports the investigation of the XeCl excimer laser as a cutting-ablating tool for human fibrocartilage and hyaline cartilage. Quantitative measurements were made of tissue ablation rates as a function of fluence in meniscal fibrocartilage and articular hyaline cartilage. A force of 1.47 Newtons was applied to an 800-microns fiber with the laser delivering a range of fluences (40-190 mJ/mm2) firing at a frequency of 5 Hz. To assess the effect of repetition rate on depth per pulse, a set of measurements was made at a constant fluence of 60 mJ/mm2, with the repetition rate varying from 10 to 40 Hz. Histologic and morphometric analysis of preserved specimens was performed using light microscopy. The results of these studies revealed that the ablation rate was directly proportional to fluence over the range tested. Fibrocartilage was ablated at a rate 2.56 times faster than hyaline cartilage. Repetition rate had no effect on the penetration per pulse. Adjacent tissue damage was noted to be minimal (10-70 microns). The excimer laser achieved ablation rates adequate for arthroscopic applications.
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Affiliation(s)
- J A Prodoehl
- Medical College of Pennsylvania, Philadelphia 19129
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Dyer PE, Khosroshahi ME, Tuft SJ. Studies of laser-induced cavitation and tissue ablation in saline using a fibre-delivered pulsed HF laser. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf00325245] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Nakamura F, Kvasnicka J, Levame M, Lange F, Bousbaa H, Geschwind HJ. Acute response of the arterial wall to pulsed laser irradiation. Lasers Surg Med 1993; 13:412-20. [PMID: 8366740 DOI: 10.1002/lsm.1900130404] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This study was designed to examine the acute response of normal arterial wall to pulsed laser irradiation. Irradiation with an Excimer or a Holmium YAG laser was performed in 15 normal iliac sites of 8 male New Zealand white rabbits. The excimer laser was operated at 308 nm, 25 Hz, 50 mJ/mm2/pulse, and 135 nsec/pulse and the Ho:YAG laser was operated at 2.1 microns, 3.5 Hz, 400 mJ/pulse, 250 microseconds/pulse. The excimer and Ho:YAG laser were coupled into a multifiber wire-guided catheter of 1.4 and 1.5 mm diameter, respectively. The mean luminal diameter increased similarly from 2.01 +/- 0.29 to 2.46 +/- 0.27 mm (P < 0.0005) and from 2.09 +/- 0.53 to 2.45 +/- 0.30 mm (P < 0.005) after excimer and Ho:YAG laser irradiation, respectively. Perforation occurred in 3 of 15 Ho:YAG irradiated sites and 0 of 15 excimer laser irradiated sites. The sites irradiated with excimer or Ho:YAG laser had similar histologic features, consisting of shedding of the endothelium, disorganization of internal elastic lamina, localized necrosis of vascular smooth muscle cells, and fissures in the medial layer. However, the sites irradiated with excimer laser had lower grading scores than those irradiated with the Ho:YAG laser (P < 0.05). Irradiation with excimer or Ho:YAG laser of normal arteries results in: (1) vasodilation of the irradiated artery; (2) localized mechanical vascular injury, and (3) Ho:YAG laser induces more severe damage to the arterial wall than excimer.
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Affiliation(s)
- F Nakamura
- Unité d'Hémodynamique et de Cardiologie Interventionnelle, University Hospital Henri Mondor, University of Paris XII, Créteil, France
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Bittl JA, Sanborn TA, Abela GS, Isner JM. Wire-guided excimer laser coronary angioplasty: instrument selection, lesion characterization, and operator technique. J Interv Cardiol 1992; 5:275-91. [PMID: 10150967 DOI: 10.1111/j.1540-8183.1992.tb00832.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Laser angioplasty has now been successfully performed on over 2,000 patients worldwide. Two systems (Advanced Interventional Systems, and Spectranetics, Corp.) have now received initial approval from the Food and Drug Administration. As with all new interventional techniques designed as an alternative to balloon angioplasty, there are a variety of instrument related issues that merit consideration in terms of patient selection as well as operator technique. While the ultimate role of laser angioplasty in the percutaneous revascularization of coronary artery disease remains to be established with certainty, laser angioplasty is, in fact, being currently used on a widespread basis as an alternative or an adjunct to balloon angioplasty in a large number of centers worldwide. Industry projections suggest that the use of this technique will increase further over the next decade. Accordingly, the purpose of this article is to discuss specific issues regarding instrumentation, native anatomical considerations, operator technique, and complications that relate specifically to the applied use of this technology as it is currently being used.
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Affiliation(s)
- J A Bittl
- Departments of Medicine (Cardiology), Brigham and Women's Hospital and Deaconess Hospital, Harvard Medical School, Boston, Massachusetts
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Arcoria CJ, Lippas MG, Speros P, Wagner MJ. Pulpal effects of argon: fluoride excimer laser irradiation and acid-etching of rat molar enamel. J Dent 1992; 20:100-7. [PMID: 1564179 DOI: 10.1016/0300-5712(92)90114-r] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The reaction of enamel, dentine and pulpal tissues to exposure from a laser beam has been shown to depend on the type of laser medium used. The objective of this study was to examine the pulpal response in rat molars after external enamel surface treatment with either an Ar:F excimer laser or acid-gel application. Maxillary right molar occlusal surfaces in 22 animals were irradiated (energy density = 45.0 J/cm2). Maxillary left molar occlusal surfaces were treated with 37 per cent phosphoric acid for 30 s. Untreated mandibular right molars served as controls. At two postoperative time periods (1 and 6 weeks), molars were removed, sectioned, stained (H&E) and scored. Data analysis indicated no significant difference between Ar:F irradiation and controls at 1 week. Treatment with laser or acid-etching left a similar degree of pathosis at 1 and 6 weeks. Although the Ar:F excimer laser produced a more exaggerated pulp response than controls at 6 weeks, tissue vitality was maintained. The Ar:F excimer laser may be useful for ablating vital tooth structure since pulpal tissue in rat molars exhibited no damage in response to low-power irradiation.
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Affiliation(s)
- C J Arcoria
- Department of Operative Dentistry, Baylor College of Dentistry, Dallas, Texas 75246
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Preisack MB, Neu W, Nyga R, Wehrmann M, Haase KK, Karsch KR. Ultrafast imaging of tissue ablation by a XeCl excimer laser in saline. Lasers Surg Med 1992; 12:520-7. [PMID: 1406005 DOI: 10.1002/lsm.1900120511] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To determine the temporal evolution of laser induced tissue ablation, arterial wall specimens with either hard calcified or fatty plaques and normal tissue were irradiated in a 0.9% saline solution using a XeCl excimer laser (wavelength 308 nm, energy fluence 7 J/cm2, pulse width 30 ns) through a 600 microns fused silica fiber pointing perpendicular either at a 0.5 mm distance or in direct contact to the vascular surface. Radiation of a pulsed dye laser (wavelength 580 nm) was used to illuminate the tissue surface. The ablation process and the arising bubble above the tissue surface were recorded with a CCD camera attached to a computer based image-processing system. Spherical cavitation bubbles and small tissue particles emerging from the irradiated area have been recorded. The volume of this bubble increased faster for calcified plaques than for normal tissue.
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Affiliation(s)
- M B Preisack
- Division of Cardiology, Tübingen University, Göttingen, Germany
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Lustmann J, Ulmansky M, Fuxbrunner A, Lewis A. Photoacoustic injury and bone healing following 193nm excimer laser ablation. Lasers Surg Med 1992; 12:390-6. [PMID: 1495367 DOI: 10.1002/lsm.1900120407] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The argon-fluoride excimer laser was investigated as a cutting-ablating tool for bone surgery. A total of 52 rats were divided into two experimental groups and two control groups. In one experimental group cortical bone defects were made; in another experimental group defects penetrating into the medullary space were performed. In the two control groups similar defects were achieved using water-cooled carbide burs. The rats were sacrificed on each of the 3, 7, 10, 20, 30, and 40 postoperative day. The cortical bone, the medullary space, and the extrabony tissue were examined by means of light microscopy. In both experimental groups, bone damage, represented by osteocyte destruction, extended to 1,050-1,450 microns ahead from the irradiated site, and bone healing was very much impaired. In the control groups no histological changes could be identified and bone healing appeared to be within normal limits. We believe this extensive bone damage, following 193 nm irradiation, to be a result of photoacoustic waves propagating in the bone following each pulse. In view of our results we feel that excimer lasers presently in use are not suitable for bone surgery. This problem of photoacoustic damage can be overcome in one of two ways: by designing a CW excimer laser or by reducing the pulse width to the picosecond regime.
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Affiliation(s)
- J Lustmann
- Department of Oral and Maxillofacial Surgery, Hebrew University, Hadassah School of Dental Medicine, Jerusalem, Israel
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