The development of optical methods in modern medicine in the areas of diagnostics,therapy,and surgery has stimulated the investigation of optical properties of various biological tissues,since the efficacy of laser tr...The development of optical methods in modern medicine in the areas of diagnostics,therapy,and surgery has stimulated the investigation of optical properties of various biological tissues,since the efficacy of laser treatment depends on the photon propagation and fluence rate distribution within irradiated tissues.In this work,an overview of published absorption and scattering properties of skin and subcutaneous tissues measured in wide wavelength range is presented.Basic principles of measurements of the tissue optical properties and techniques used for processing of the measured data are outlined.展开更多
Complex study of glycerol effects on the skin tissue was performed.The change in optical,weight and geometrical parameters of the rat skin under the action of the glycerol solutions was studied ex vivo.Possible mechan...Complex study of glycerol effects on the skin tissue was performed.The change in optical,weight and geometrical parameters of the rat skin under the action of the glycerol solutions was studied ex vivo.Possible mechanisms of the skin optical clearing under the action of glycerol solutions of different concentrations were discussed.The results can be helpful for refinement of models developed to evaluate the effective diffusion coefficients of glycerol in tissues.展开更多
One of the major challenges in imaging biological tissues using optical techniques,such as optical coherence tomography(OCT),is the lack of light penetration due to highly turbid structures within the tissue.Optical c...One of the major challenges in imaging biological tissues using optical techniques,such as optical coherence tomography(OCT),is the lack of light penetration due to highly turbid structures within the tissue.Optical clearing techniques enable the biological samples to be more optically homogeneous,allowing for deeper penetration of light into the tissue.This study investigates the effect of optical clearing utilizing various concentrations of glucose solution(10%,30%,and 50%)on porcine skin.A gold-plated mirror was imaged beneath the tissue and percentage clearing was determined by monitoring the change in reflected light intensity from the mirror over time.The ratio of percentage clearing per tissue thickness for 10%,30% and 50% glucose was determined to be 4.7±1.6%mm^(−1)(n=6),10.6±2.0%mm^(−1)(n=7)and 21.8±2.2%mm^(−1)(n=5),respectively.It was concluded that while higher glucose concentration has the highest optical clearing effect,a suitable concentration should be chosen for the purpose of clearing,considering the osmotic stress on the tissue sample.展开更多
The goal of this work was to evaluate the safety and efficacy of the Red Light Emitted Toothbrush(R-LETB)emitting at wavelength of 663 nm with power density of 3.3mW/cm2 in combination with 0.1%-methylene blue(MB)solu...The goal of this work was to evaluate the safety and efficacy of the Red Light Emitted Toothbrush(R-LETB)emitting at wavelength of 663 nm with power density of 3.3mW/cm2 in combination with 0.1%-methylene blue(MB)solution for the reduction of plaque and treatment of gingivitis.A microbiological in vitro study and a pilot clinical study were conducted.The microbiological study has shown total suppression of pathogenicflora after a 3-min exposure to the dye solution followed by a 20-sec treatment with the R-LETB.For the clinical study,37 subjects of both sexes with gingivitis were enrolled and randomly assigned to one of two groups.Subjects in thefirst(treatment)group were instructed to rinse their mouth with MB solution provided for 1 min and then brush the teeth with the R-LETB and standardized toothpaste.The second(control)group used only the toothpaste and a regular toothbrush.Subjects in both groups followed their respective procedures 2 times a day(morning and evening)for 30 days.Indices of plaque,gingival bleeding,and inflammation were evaluated at 14-day and 30-day timepoints.In the both groups,all indices improved in comparison with baseline.However,the treatment group demonstrated more pronounced improvement of the studied indices that was attributed to additional anti-microbial action of red light and MB on gum tissue.Thus,the use of R-LETB with MB appears to have a multifactor therapeutic action on oral pathological microflora:mechanical removal of the bacteria and suppressing action on microorganisms due to photodynamic reaction.展开更多
Nanocomposites （NCs） consisting of a gold nanorod core and a mesoporous silica shell doped with hematoporphyrin （HP） have been fabricated in order to improve the efficiency of cancer treatment by combining phototh...Nanocomposites （NCs） consisting of a gold nanorod core and a mesoporous silica shell doped with hematoporphyrin （HP） have been fabricated in order to improve the efficiency of cancer treatment by combining photothermal and photodynamic therapies （PDT ＋ PTT） in vivo. In addition to the long-wavelength plasmon resonance near 810-830 nm, the fabricated NCs exhibited a 400-nm absorbance peak corresponding to bound HP, generated singlet oxygen under 633-nm excitation near the 632.5-nm Q-band, and produced heat under a 808-nm near-infrared （NIR） laser irradiation. These modalities were used for a combined PDT ＋ PTT treatment of large （about 3 cm3） solid tumors in vivo with a xenorafted tumor rat model. NCs were directly injected into tumors and irradiated simultaneously with 633-nm and 808-nm lasers to stimulate the combined photodynamic and photothermal activities of NCs. The efficiency of the combined therapy was evaluated by optical coherence tomography, histological analysis, and by measurements of the tumor volume growth during a 21-day period. The NC-mediated PDT led to weak changes in tissue histology and to a moderate 20% decrease in the tumor volume. In contrast, the combined PDT ＋ PTT treatment resulted in the large-area tumor necrosis and led to dramatic decrease in the tumor volume.展开更多
文摘The development of optical methods in modern medicine in the areas of diagnostics,therapy,and surgery has stimulated the investigation of optical properties of various biological tissues,since the efficacy of laser treatment depends on the photon propagation and fluence rate distribution within irradiated tissues.In this work,an overview of published absorption and scattering properties of skin and subcutaneous tissues measured in wide wavelength range is presented.Basic principles of measurements of the tissue optical properties and techniques used for processing of the measured data are outlined.
基金This work was carried out under the support from the Russian Foundation for Basic Research(Grant Nos.18-52-16025 and 19-32-90224)The Fund for Promoting Innovation grant UMNIK-19/HealthNet.NTI-2019 No.15929GU/2020 of 07.23.2020(code 0059878,application(U-65096)).
文摘Complex study of glycerol effects on the skin tissue was performed.The change in optical,weight and geometrical parameters of the rat skin under the action of the glycerol solutions was studied ex vivo.Possible mechanisms of the skin optical clearing under the action of glycerol solutions of different concentrations were discussed.The results can be helpful for refinement of models developed to evaluate the effective diffusion coefficients of glycerol in tissues.
基金the Institute of Biomedical Imaging Sciences(IBIS-97708)CRDF(RUB1-2932-SR-08)+3 种基金NSF(CMMI-0900743)supported by grants 224014 Photonics4life-FP7-ICT-2007-2RF Ministry of Science and Education 2.1.1/4989 and 2.2.1.1/2950,Project 1.4.09 of Federal Agency of Education of RFthe RF Governmental contracts 02.740.11.0484 and 02.740.11.0770.
文摘One of the major challenges in imaging biological tissues using optical techniques,such as optical coherence tomography(OCT),is the lack of light penetration due to highly turbid structures within the tissue.Optical clearing techniques enable the biological samples to be more optically homogeneous,allowing for deeper penetration of light into the tissue.This study investigates the effect of optical clearing utilizing various concentrations of glucose solution(10%,30%,and 50%)on porcine skin.A gold-plated mirror was imaged beneath the tissue and percentage clearing was determined by monitoring the change in reflected light intensity from the mirror over time.The ratio of percentage clearing per tissue thickness for 10%,30% and 50% glucose was determined to be 4.7±1.6%mm^(−1)(n=6),10.6±2.0%mm^(−1)(n=7)and 21.8±2.2%mm^(−1)(n=5),respectively.It was concluded that while higher glucose concentration has the highest optical clearing effect,a suitable concentration should be chosen for the purpose of clearing,considering the osmotic stress on the tissue sample.
基金The authors are grateful to Palomar Medical Technologies,Inc.(Burlington,MA,USA)for funding this work.The research described in this paper was also supported by grant No.224014 PHOTONICS4LIFE of FP7-ICT-2007-2(2008-2013)Governmental contracts 02.740.11.0484 and 02.740.11.0879.
文摘The goal of this work was to evaluate the safety and efficacy of the Red Light Emitted Toothbrush(R-LETB)emitting at wavelength of 663 nm with power density of 3.3mW/cm2 in combination with 0.1%-methylene blue(MB)solution for the reduction of plaque and treatment of gingivitis.A microbiological in vitro study and a pilot clinical study were conducted.The microbiological study has shown total suppression of pathogenicflora after a 3-min exposure to the dye solution followed by a 20-sec treatment with the R-LETB.For the clinical study,37 subjects of both sexes with gingivitis were enrolled and randomly assigned to one of two groups.Subjects in thefirst(treatment)group were instructed to rinse their mouth with MB solution provided for 1 min and then brush the teeth with the R-LETB and standardized toothpaste.The second(control)group used only the toothpaste and a regular toothbrush.Subjects in both groups followed their respective procedures 2 times a day(morning and evening)for 30 days.Indices of plaque,gingival bleeding,and inflammation were evaluated at 14-day and 30-day timepoints.In the both groups,all indices improved in comparison with baseline.However,the treatment group demonstrated more pronounced improvement of the studied indices that was attributed to additional anti-microbial action of red light and MB on gum tissue.Thus,the use of R-LETB with MB appears to have a multifactor therapeutic action on oral pathological microflora:mechanical removal of the bacteria and suppressing action on microorganisms due to photodynamic reaction.
文摘Nanocomposites （NCs） consisting of a gold nanorod core and a mesoporous silica shell doped with hematoporphyrin （HP） have been fabricated in order to improve the efficiency of cancer treatment by combining photothermal and photodynamic therapies （PDT ＋ PTT） in vivo. In addition to the long-wavelength plasmon resonance near 810-830 nm, the fabricated NCs exhibited a 400-nm absorbance peak corresponding to bound HP, generated singlet oxygen under 633-nm excitation near the 632.5-nm Q-band, and produced heat under a 808-nm near-infrared （NIR） laser irradiation. These modalities were used for a combined PDT ＋ PTT treatment of large （about 3 cm3） solid tumors in vivo with a xenorafted tumor rat model. NCs were directly injected into tumors and irradiated simultaneously with 633-nm and 808-nm lasers to stimulate the combined photodynamic and photothermal activities of NCs. The efficiency of the combined therapy was evaluated by optical coherence tomography, histological analysis, and by measurements of the tumor volume growth during a 21-day period. The NC-mediated PDT led to weak changes in tissue histology and to a moderate 20% decrease in the tumor volume. In contrast, the combined PDT ＋ PTT treatment resulted in the large-area tumor necrosis and led to dramatic decrease in the tumor volume.
