Abstract In this paper, a two-dimensional photonic crystal biosensor for medical applications based on two waveguides and a nanocavity is presented. The waveguides and nanocavity are created by introducing line and point defects into a photonic crystal, respectively. It could be shown that by injecting an analyte into a sensing hole, and thus changing its refractive index, may shift the resonant wavelength. The proposed structure is designed for the wavelength range of 1.5259–1.6934 μm. Sensitivity, the most important biosensor parameter, was studied and found to be approximately equal to 83.75 nm/refractive index units (RIU). An important specification of this structure is its very small dimensions. Two-dimensional finite-difference time domain and plane-wave expansion methods were used for both to simulate the proposed structure and to obtain the band diagrams.
{"title":"Design of a new two-dimensional optical biosensor using photonic crystal waveguides and a nanocavity","authors":"H. Mohsenirad, S. Olyaee, M. Seifouri","doi":"10.1515/plm-2015-0033","DOIUrl":"https://doi.org/10.1515/plm-2015-0033","url":null,"abstract":"Abstract In this paper, a two-dimensional photonic crystal biosensor for medical applications based on two waveguides and a nanocavity is presented. The waveguides and nanocavity are created by introducing line and point defects into a photonic crystal, respectively. It could be shown that by injecting an analyte into a sensing hole, and thus changing its refractive index, may shift the resonant wavelength. The proposed structure is designed for the wavelength range of 1.5259–1.6934 μm. Sensitivity, the most important biosensor parameter, was studied and found to be approximately equal to 83.75 nm/refractive index units (RIU). An important specification of this structure is its very small dimensions. Two-dimensional finite-difference time domain and plane-wave expansion methods were used for both to simulate the proposed structure and to obtain the band diagrams.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"2 1","pages":"51 - 56"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87941065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Background: Diffuser fibers have been used for some time in the fields of laser-induced thermotherapy and photodynamic therapy. For their applicability the breaking strength, the thermostability and a homogeneous radiation profile are of great importance. Flexible applicators offer special benefits because they introduce a totally new range of application possibilities. Objective: The aim of the presented investigations was to develop a totally new flexible diffuser fiber generation which can be produced cheaper and without the use of any further materials. For this purpose it was proposed to induce scattering micro dots directly into silica fibers by generating a local change of the refractive index in the core of the optical fiber. The resulting diffuser was expected to create a homogeneous radiation profile containing at least 80% of the light coupled into the optical fiber, i.e. less than 20% prograde (forward) emission. Materials and methods: On the basis of former research results, scattering micro dots were induced linearly into the core of an optical silica fiber through a multiple photon process using a femtosecond laser. In addition to the macroscopic optical control by means of a microscope, the form of the radiation profile was examined as well as the non-scattered forward emission which depends on a variety of influencing factors. The processing was optimized according to the observations made. The thermostability of the developed prototypes was assessed by using a thermocamera, and the minimal bending radius was determined. Finally the prototypes were tested and validated ex vivo using porcine liver. Results: An influence of the processing power, the number and radial position of the scattering micro dots as well as the therapeutic coupled-in wavelength onto the form of the radiation profile and the non-scattered forward emission was determined. Both the form of the radiation profile and the prograde emission were found to be independent of the therapeutic laser power coupled into the fiber. The developed prototype had a nearly homogeneous radiation profile, a forward emission of 12.8±2.1% in average, and a minimum bending radius of 31±6 mm. Conclusion: The non-scattered forward emission of the developed diffusers was within the objective of below 20% and the radiation profile was very nearly homogeneous. In order to improve the reproducibility of the production process, an improved fixation apparatus needs to be developed.
{"title":"Internal structuring of silica glass fibers: Requirements for scattered light applicators for the usability in medicine","authors":"J. Köcher, V. Knappe, M. Schwagmeier","doi":"10.1515/plm-2015-0014","DOIUrl":"https://doi.org/10.1515/plm-2015-0014","url":null,"abstract":"Abstract Background: Diffuser fibers have been used for some time in the fields of laser-induced thermotherapy and photodynamic therapy. For their applicability the breaking strength, the thermostability and a homogeneous radiation profile are of great importance. Flexible applicators offer special benefits because they introduce a totally new range of application possibilities. Objective: The aim of the presented investigations was to develop a totally new flexible diffuser fiber generation which can be produced cheaper and without the use of any further materials. For this purpose it was proposed to induce scattering micro dots directly into silica fibers by generating a local change of the refractive index in the core of the optical fiber. The resulting diffuser was expected to create a homogeneous radiation profile containing at least 80% of the light coupled into the optical fiber, i.e. less than 20% prograde (forward) emission. Materials and methods: On the basis of former research results, scattering micro dots were induced linearly into the core of an optical silica fiber through a multiple photon process using a femtosecond laser. In addition to the macroscopic optical control by means of a microscope, the form of the radiation profile was examined as well as the non-scattered forward emission which depends on a variety of influencing factors. The processing was optimized according to the observations made. The thermostability of the developed prototypes was assessed by using a thermocamera, and the minimal bending radius was determined. Finally the prototypes were tested and validated ex vivo using porcine liver. Results: An influence of the processing power, the number and radial position of the scattering micro dots as well as the therapeutic coupled-in wavelength onto the form of the radiation profile and the non-scattered forward emission was determined. Both the form of the radiation profile and the prograde emission were found to be independent of the therapeutic laser power coupled into the fiber. The developed prototype had a nearly homogeneous radiation profile, a forward emission of 12.8±2.1% in average, and a minimum bending radius of 31±6 mm. Conclusion: The non-scattered forward emission of the developed diffusers was within the objective of below 20% and the radiation profile was very nearly homogeneous. In order to improve the reproducibility of the production process, an improved fixation apparatus needs to be developed.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":" 5","pages":"57 - 67"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91414167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Human blood is a valuable and limited resource. Globally, over 100 million blood bags are collected annually to provide fresh blood reserves, e.g. for emergency and cancer therapy patients. The demand for blood bags is constantly increasing, and it is becoming increasingly difficult to meet this demand. Currently the amount of the active ingredient contained in a blood bag – the oxygen carrier hemoglobin (red blood cells) – is only given within a range. Unlike all other drugs, the exact dosage that is administered during a transfusion is not known. At the moment there is no non-destructive method available on the market to determine the exact amount of hemoglobin in the sterile blood bag.
{"title":"LMTB winner of the Innovation Award Berlin Brandenburg 2015","authors":"Michael Wrobel","doi":"10.1515/plm-2015-0043","DOIUrl":"https://doi.org/10.1515/plm-2015-0043","url":null,"abstract":"Human blood is a valuable and limited resource. Globally, over 100 million blood bags are collected annually to provide fresh blood reserves, e.g. for emergency and cancer therapy patients. The demand for blood bags is constantly increasing, and it is becoming increasingly difficult to meet this demand. Currently the amount of the active ingredient contained in a blood bag – the oxygen carrier hemoglobin (red blood cells) – is only given within a range. Unlike all other drugs, the exact dosage that is administered during a transfusion is not known. At the moment there is no non-destructive method available on the market to determine the exact amount of hemoglobin in the sterile blood bag.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"47 1","pages":"77 - 78"},"PeriodicalIF":0.0,"publicationDate":"2016-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74151191","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
K. Stock, D. Steigenhöfer, T. Pongratz, Rainer Graser, R. Sroka
Abstract Background and objective: Endoscopic laser lithotripsy is the preferred technique for minimally invasive destruction of ureteral and kidney stones, and is mostly performed by pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser irradiation. The absorbed laser energy heats the water creating a vapor bubble which collapses after the laser pulse, thus producing a shock wave. Part of the laser energy strikes the stone through the vapor bubble and induces thermomechanical material removal. Aim of the present study was to visualize the behavior and the dynamics of the cavitation bubble using a specially developed ultra-short-time illumination system and then to determine important characteristics related to clinically used laser and application parameters for a more detailed investigation in the future. Materials and methods: In accordance with Toepler’s Schlieren technique, in the ultra-short-time-illumination set-up the cavitation bubble which had been induced by Ho:YAG laser irradiation at the fiber end, was illuminated by two Q-switched lasers and the process was imaged in high contrast on a video camera. Cavitation bubbles were induced using different pulse energies (500 mJ/pulse and 2000 mJ/pulse) and fiber core diameters (230 μm and 600 μm) and the bubble dynamics were recorded at different times relative to the Ho:YAG laser pulse. The time-dependent development of the bubble formation was determined from the recordings by measuring the bubble diameter in horizontal and vertical directions, together with the volume and localization of the center of the bubble collapse. Results: The results show that the bubble dynamics can be visualized and studied with both high contrast and high temporal resolution. The bubble volume increases with pulse energy and with fiber diameter. The bubble shape is almost round when a larger fiber core diameter is used, and elliptical when using a fiber of smaller core diameter. Moreover, the center of the resulting bubble is slightly further away from the fiber end and the center of the bubble collapse for a smaller fiber core diameter. Conclusion: The experimental set-up developed gives a better understanding of the bubble dynamics. The experiments indicate that the distance between fiber tip and target surface, as well as the laser parameters used have considerable impact on the cavitation bubble dynamics. Both the bubble dynamics and their influence on the stone fragmentation process require further investigation.
{"title":"Investigation on cavitation bubble dynamics induced by clinically available Ho:YAG lasers","authors":"K. Stock, D. Steigenhöfer, T. Pongratz, Rainer Graser, R. Sroka","doi":"10.1515/plm-2015-0039","DOIUrl":"https://doi.org/10.1515/plm-2015-0039","url":null,"abstract":"Abstract Background and objective: Endoscopic laser lithotripsy is the preferred technique for minimally invasive destruction of ureteral and kidney stones, and is mostly performed by pulsed holmium:yttrium-aluminum-garnet (Ho:YAG) laser irradiation. The absorbed laser energy heats the water creating a vapor bubble which collapses after the laser pulse, thus producing a shock wave. Part of the laser energy strikes the stone through the vapor bubble and induces thermomechanical material removal. Aim of the present study was to visualize the behavior and the dynamics of the cavitation bubble using a specially developed ultra-short-time illumination system and then to determine important characteristics related to clinically used laser and application parameters for a more detailed investigation in the future. Materials and methods: In accordance with Toepler’s Schlieren technique, in the ultra-short-time-illumination set-up the cavitation bubble which had been induced by Ho:YAG laser irradiation at the fiber end, was illuminated by two Q-switched lasers and the process was imaged in high contrast on a video camera. Cavitation bubbles were induced using different pulse energies (500 mJ/pulse and 2000 mJ/pulse) and fiber core diameters (230 μm and 600 μm) and the bubble dynamics were recorded at different times relative to the Ho:YAG laser pulse. The time-dependent development of the bubble formation was determined from the recordings by measuring the bubble diameter in horizontal and vertical directions, together with the volume and localization of the center of the bubble collapse. Results: The results show that the bubble dynamics can be visualized and studied with both high contrast and high temporal resolution. The bubble volume increases with pulse energy and with fiber diameter. The bubble shape is almost round when a larger fiber core diameter is used, and elliptical when using a fiber of smaller core diameter. Moreover, the center of the resulting bubble is slightly further away from the fiber end and the center of the bubble collapse for a smaller fiber core diameter. Conclusion: The experimental set-up developed gives a better understanding of the bubble dynamics. The experiments indicate that the distance between fiber tip and target surface, as well as the laser parameters used have considerable impact on the cavitation bubble dynamics. Both the bubble dynamics and their influence on the stone fragmentation process require further investigation.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"49 1","pages":"141 - 150"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76885029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract: Optical coherence tomography (OCT) is a modern technique for imaging of internal structures of biotissue of up to several millimeters in depth with a resolution of several micrometers. However, various external conditions can distort the diagnostic capabilities of an OCT image. Mechanical compression and temperature regime are the two conditions which mostly affect the diagnostic OCT images obtained with a contact probe. It is shown here that the application of compression to human skin induces a decrease in contrast of the stratum corneum-epidermis junction and an increase in contrast of the epidermis-dermis junction. With regard to these junctions, a preliminary change of biotissue temperature induces additional changes in the contrast, with opposing effects in case of heating and cooling.
{"title":"Effect of temperature regime and compression in OCT imaging of skin in vivo","authors":"P. Agrba, M. Kirillin","doi":"10.1515/plm-2015-0044","DOIUrl":"https://doi.org/10.1515/plm-2015-0044","url":null,"abstract":"Abstract: Optical coherence tomography (OCT) is a modern technique for imaging of internal structures of biotissue of up to several millimeters in depth with a resolution of several micrometers. However, various external conditions can distort the diagnostic capabilities of an OCT image. Mechanical compression and temperature regime are the two conditions which mostly affect the diagnostic OCT images obtained with a contact probe. It is shown here that the application of compression to human skin induces a decrease in contrast of the stratum corneum-epidermis junction and an increase in contrast of the epidermis-dermis junction. With regard to these junctions, a preliminary change of biotissue temperature induces additional changes in the contrast, with opposing effects in case of heating and cooling.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"94 1","pages":"161 - 168"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91083041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Background and objective: Pancreatic cancer has long been a leading cause of cancer death. Few patients are suitable for surgery and for those who are not, the response to treatment is generally poor. No more than about 10% survive for more than a year. Recent research has focused on focal treatment for local disease control. This review covers the development of one of the most promising options, photodynamic therapy (PDT). Methods: This review covers pre-clinical and clinical studies. Laboratory work was designed to understand the effect of PDT on the normal pancreas and surrounding tissues and on transplanted cancers in the hamster pancreas to ensure safety prior to clinical application. Essentially all clinical studies have been undertaken in University College Hospital, London. Phase-I studies used the photosensitisers mTHPC and verteporfin in patients with localised but inoperable cancers. Results: Laboratory results showed that normal pancreas, bile duct, liver, stomach and major blood vessels could tolerate PDT without any unacceptable effects on the structure and function of these organs. Necrosis that healed safely was documented in transplanted cancers. The clinical trials showed that focal necrosis could be produced in inoperable cancers with acceptable levels of complications, but considerable refinements of treatment delivery and monitoring are required before the technique will be ready for assessment in controlled clinical trials. Conclusions: PDT is showing promise for the minimally invasive treatment of localised pancreatic cancers, but it is still at an early stage of development. Much more work will be necessary to optimise techniques for applying PDT to these cancers and for combining it with other therapeutic options such as chemotherapy.
{"title":"Photodynamic therapy for cancer of the pancreas – The story so far","authors":"S. Bown","doi":"10.1515/plm-2016-0001","DOIUrl":"https://doi.org/10.1515/plm-2016-0001","url":null,"abstract":"Abstract Background and objective: Pancreatic cancer has long been a leading cause of cancer death. Few patients are suitable for surgery and for those who are not, the response to treatment is generally poor. No more than about 10% survive for more than a year. Recent research has focused on focal treatment for local disease control. This review covers the development of one of the most promising options, photodynamic therapy (PDT). Methods: This review covers pre-clinical and clinical studies. Laboratory work was designed to understand the effect of PDT on the normal pancreas and surrounding tissues and on transplanted cancers in the hamster pancreas to ensure safety prior to clinical application. Essentially all clinical studies have been undertaken in University College Hospital, London. Phase-I studies used the photosensitisers mTHPC and verteporfin in patients with localised but inoperable cancers. Results: Laboratory results showed that normal pancreas, bile duct, liver, stomach and major blood vessels could tolerate PDT without any unacceptable effects on the structure and function of these organs. Necrosis that healed safely was documented in transplanted cancers. The clinical trials showed that focal necrosis could be produced in inoperable cancers with acceptable levels of complications, but considerable refinements of treatment delivery and monitoring are required before the technique will be ready for assessment in controlled clinical trials. Conclusions: PDT is showing promise for the minimally invasive treatment of localised pancreatic cancers, but it is still at an early stage of development. Much more work will be necessary to optimise techniques for applying PDT to these cancers and for combining it with other therapeutic options such as chemotherapy.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"102 1","pages":"100 - 91"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86101245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
It has been more than 50 years since Theodore Maiman first presented the pulsed laser beam in public. Since then this unique energy source – namely, light amplification by stimulated emission of radiation (LASER) – has initiated a new age in surgery and medicine. In the early years after its invention only a relatively small group of international clinicians and researchers were engaged in the development of improved surgical procedures and clinical therapies that were advantageous for those patients who either could not be treated successfully in a conventional way, or could be treated better than before by using LASER. Driven by these developments, national laser societies were formed, such as the American Society for Laser Medicine and Surgery (ASLMS) and the German Society for Laser Medicine (DGLM), followed by the first international society, the International Society for Laser Surgery and Medicine (ISLSM). As a result, within 10 years the number of medical LASER users increased to several thousand worldwide. In the following decades laser surgery and medicine developed into remarkable stage with an ever-increasing number of applications. It is a technique that is used to transport energy to ablate, coagulate or alter tissue photomechanically or photochemically, as well as to change function or elucidate specific information from the tissue; all these methods allow its multidisciplinary use – with steady growth. The LASER is now well established in many medical disciplines and it has found general acceptance by national and private health plans. Currently diagnostic and therapeutic applications are being developed with different speed. While laser diagnostics research is leading the field, only a few therapeutic techniques have made the leap from bench to bedside lately. It is interesting to note here that a considerable number of LASER and biophotonic techniques have already been integrated into the medical guidelines and that they are being discussed within the medical disciplines rather than within the biophotonics community. However, the amount of research regarding LASER and biophotonics in medicine is steadily increasing, in that the users and their aims are as diverse as they ever were. Within this process, laser medicine and biophotonics are not only related to clinical application. There are many research fields but only a few key applications, with other competitive technologies also on the increase. Reimbursement of costs by social welfare schemes still remains a critical point and industrial investment and research funding are not enough to bridge the gap between the bench and the bedside. In spite of this, there have been many optical innovations in laboratory medicine, histology and pathology, LASER and light applications, and diagnostic procedures.
{"title":"Photonics & Lasers in Medicine – Dissolved in diversity","authors":"C. Philipp, R. Sroka","doi":"10.1515/PLM-2016-0034","DOIUrl":"https://doi.org/10.1515/PLM-2016-0034","url":null,"abstract":"It has been more than 50 years since Theodore Maiman first presented the pulsed laser beam in public. Since then this unique energy source – namely, light amplification by stimulated emission of radiation (LASER) – has initiated a new age in surgery and medicine. In the early years after its invention only a relatively small group of international clinicians and researchers were engaged in the development of improved surgical procedures and clinical therapies that were advantageous for those patients who either could not be treated successfully in a conventional way, or could be treated better than before by using LASER. Driven by these developments, national laser societies were formed, such as the American Society for Laser Medicine and Surgery (ASLMS) and the German Society for Laser Medicine (DGLM), followed by the first international society, the International Society for Laser Surgery and Medicine (ISLSM). As a result, within 10 years the number of medical LASER users increased to several thousand worldwide. In the following decades laser surgery and medicine developed into remarkable stage with an ever-increasing number of applications. It is a technique that is used to transport energy to ablate, coagulate or alter tissue photomechanically or photochemically, as well as to change function or elucidate specific information from the tissue; all these methods allow its multidisciplinary use – with steady growth. The LASER is now well established in many medical disciplines and it has found general acceptance by national and private health plans. Currently diagnostic and therapeutic applications are being developed with different speed. While laser diagnostics research is leading the field, only a few therapeutic techniques have made the leap from bench to bedside lately. It is interesting to note here that a considerable number of LASER and biophotonic techniques have already been integrated into the medical guidelines and that they are being discussed within the medical disciplines rather than within the biophotonics community. However, the amount of research regarding LASER and biophotonics in medicine is steadily increasing, in that the users and their aims are as diverse as they ever were. Within this process, laser medicine and biophotonics are not only related to clinical application. There are many research fields but only a few key applications, with other competitive technologies also on the increase. Reimbursement of costs by social welfare schemes still remains a critical point and industrial investment and research funding are not enough to bridge the gap between the bench and the bedside. In spite of this, there have been many optical innovations in laboratory medicine, histology and pathology, LASER and light applications, and diagnostic procedures.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"40 1","pages":"249 - 250"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81122167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The uniformity of light dosimetry is an important parameter that affects the efficacy of photodynamic therapy (PDT). Although this uniformity can be improved by a three-dimensional (3D) digital PDT illumination system, it has a low field-of-view (FOV) utilization rate. A checkerboard calibration method using color coding is proposed to calibrate both the projector and camera of the system with a broad common FOV. Experiments reveal that the proposed method increases the utilization rate by up to three times compared with noncolor-coding methods with almost the same accuracy. A fine distinction of phantom lesions in the 3D system can be obtained by clustering, which may be used to optimize the treatment and light-dosimetry evaluation.
{"title":"Calibration of a three-dimensional photodynamic therapy illumination system and its segmentation assessment for port-wine stains","authors":"Yun-qiu Feng, Xiaoming Hu, Ya Zhou, Yong Wang","doi":"10.1515/plm-2016-0014","DOIUrl":"https://doi.org/10.1515/plm-2016-0014","url":null,"abstract":"Abstract The uniformity of light dosimetry is an important parameter that affects the efficacy of photodynamic therapy (PDT). Although this uniformity can be improved by a three-dimensional (3D) digital PDT illumination system, it has a low field-of-view (FOV) utilization rate. A checkerboard calibration method using color coding is proposed to calibrate both the projector and camera of the system with a broad common FOV. Experiments reveal that the proposed method increases the utilization rate by up to three times compared with noncolor-coding methods with almost the same accuracy. A fine distinction of phantom lesions in the 3D system can be obtained by clustering, which may be used to optimize the treatment and light-dosimetry evaluation.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"5 1","pages":"195 - 202"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82040441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract We report the use of a 577-nm wavelength high-power optically pumped semiconductor laser (HOPSL) to treat 12 patients with multiple recalcitrant non-genital warts that had not responded to conservative and invasive treatment. The patients were treated weekly using a 577 nm HOPSL connected to a scanner device. Ten patients with warts showed complete clearance after treatment. One patient had partial clearance and one did not respond at all. Slight to medium pain (visual analog scale, VAS=2–6) was reported during treatment. After treatment there was no evidence of scarring. After the 6-month follow-up there was no recurrence of the completely cleared warts.
{"title":"Treatment of recalcitrant viral warts using a 577-nm wavelength high-power optically pumped semiconductor laser","authors":"Bianca Bigge, Stefan Bigge","doi":"10.1515/plm-2016-0013","DOIUrl":"https://doi.org/10.1515/plm-2016-0013","url":null,"abstract":"Abstract We report the use of a 577-nm wavelength high-power optically pumped semiconductor laser (HOPSL) to treat 12 patients with multiple recalcitrant non-genital warts that had not responded to conservative and invasive treatment. The patients were treated weekly using a 577 nm HOPSL connected to a scanner device. Ten patients with warts showed complete clearance after treatment. One patient had partial clearance and one did not respond at all. Slight to medium pain (visual analog scale, VAS=2–6) was reported during treatment. After treatment there was no evidence of scarring. After the 6-month follow-up there was no recurrence of the completely cleared warts.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"30 1","pages":"219 - 223"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90036082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Angelov, A. Kril, R. Dimitrov, E. Borisova, L. Avramov, V. Mantareva
Abstract Background and objectives: Intensive research in the area of photodynamic therapy (PDT) has been made in recent years revealing it as a promising method for the treatment of tumors and inactivation of pathogenic microorganisms. However, for a broader application of this therapy one major challenge, namely a significant improvement of the targeted drug delivery and uptake, still remains. A possible solution of the selectivity problem could be the application of specifically functionalized photosensitizers, in particular phthalocyanine dyes. Materials and methods: Water-soluble Zn(II) phthalocyanines (ZnPcs) with four galactose moieties on non-peripheral and peripheral positions and a non-substituted Zn(II) phthalocyanine were studied for in vitro antitumor activity on three breast cancer cell lines (MCF-7, MDA-MB-231 and HBL-100). The influence of the exposure to ultraviolet (UV) (365 nm) and red (635 nm) light in non-therapeutic doses on the cellular uptake, binding and subcellular localization of three photosensitizers was investigated by confocal laser scanning microscopy. In addition, phototoxicity studies with the tested phthalocyanines on the non-tumorigenic mouse embryo cell line Balb c/3T3 (clone 31) were carried out. Results: The results indicate that the pre-treatment, namely exposure to UV or red light, influences the localization properties of the used dyes. The positions of galactose units to the ZnPc ring also influenced the uptake, localization and the photodynamic response of breast cancer cells. The results show that the galactose substitution, together with exposure to UV or red light in non-therapeutic doses, are important factors for the photodynamic effect. Conclusion: Experimental PDT with galactose-substituted ZnPcs accompanied by UV and red light pre-irradiation leads to a higher photodynamic effect towards breast tumor cells. Thus, the investigated galactopyranosyl-substituted phthalocyanines could be used as a part of the design of intelligent, stimuli-responsive nanosystems for medical applications.
{"title":"Light enhancement of in vitro antitumor activity of galactosylated phthalocyanines","authors":"I. Angelov, A. Kril, R. Dimitrov, E. Borisova, L. Avramov, V. Mantareva","doi":"10.1515/plm-2016-0002","DOIUrl":"https://doi.org/10.1515/plm-2016-0002","url":null,"abstract":"Abstract Background and objectives: Intensive research in the area of photodynamic therapy (PDT) has been made in recent years revealing it as a promising method for the treatment of tumors and inactivation of pathogenic microorganisms. However, for a broader application of this therapy one major challenge, namely a significant improvement of the targeted drug delivery and uptake, still remains. A possible solution of the selectivity problem could be the application of specifically functionalized photosensitizers, in particular phthalocyanine dyes. Materials and methods: Water-soluble Zn(II) phthalocyanines (ZnPcs) with four galactose moieties on non-peripheral and peripheral positions and a non-substituted Zn(II) phthalocyanine were studied for in vitro antitumor activity on three breast cancer cell lines (MCF-7, MDA-MB-231 and HBL-100). The influence of the exposure to ultraviolet (UV) (365 nm) and red (635 nm) light in non-therapeutic doses on the cellular uptake, binding and subcellular localization of three photosensitizers was investigated by confocal laser scanning microscopy. In addition, phototoxicity studies with the tested phthalocyanines on the non-tumorigenic mouse embryo cell line Balb c/3T3 (clone 31) were carried out. Results: The results indicate that the pre-treatment, namely exposure to UV or red light, influences the localization properties of the used dyes. The positions of galactose units to the ZnPc ring also influenced the uptake, localization and the photodynamic response of breast cancer cells. The results show that the galactose substitution, together with exposure to UV or red light in non-therapeutic doses, are important factors for the photodynamic effect. Conclusion: Experimental PDT with galactose-substituted ZnPcs accompanied by UV and red light pre-irradiation leads to a higher photodynamic effect towards breast tumor cells. Thus, the investigated galactopyranosyl-substituted phthalocyanines could be used as a part of the design of intelligent, stimuli-responsive nanosystems for medical applications.","PeriodicalId":20126,"journal":{"name":"Photonics & Lasers in Medicine","volume":"70 1","pages":"123 - 140"},"PeriodicalIF":0.0,"publicationDate":"2016-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85545477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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