Comparative analysis of single- and dual-wavelength photodynamic therapy regimes with chlorin-based photosensitizers: animal study

Abstract

Comparative analysis of single-and dual-wavelength photodynamic therapy regimes with chlorin-based photosensitizers: animal study," J.Abstract. Two pronounced absorption peaks in blue and red ranges of the chlorin-based photosensitizer (PS) absorption spectrum provide additional benefits in photodynamic therapy (PDT) performance. Differing optical properties of biological tissues in these ranges allow for both dual-wavelength diagnostics and PDT performance. We provide a comparative analysis of different PDT regimes performed with blue and red lights and their combination, with doses varying from 50 to 150 J∕cm 2 . The study was performed on the intact skin of a rabbit ear inner surface, with the use of chlorin e6 as a PS. PDT procedure protocol included monitoring of the treated site with fluorescence imaging technique to evaluate PS accumulation and photobleaching, as well as with optical coherence tomography (OCT) to register morphological and functional responses of the tissue. Optical diagnostic observations were compared with the results of histopathology examination. We demonstrated that PDT procedures with the considered regimes induce weaker organism reaction manifested by edema in normal tissue as compared to irradiation-only exposures with the same light doses. The light doses delivered with red light induce weaker tissue reaction as compared to the same doses delivered with blue light only or with a combination of red and blue lights in equal parts. Results of in-vivo OCT monitoring of tissue reaction are in agreement with the results of histopathology study.

Numerical Simulation of Enhancement of Superficial Tumor Laser Hyperthermia with Silicon Nanoparticles

“…The laser power P and the beam radius r were varied in the simulations in order to evaluate the range of optimal parameters to perform SiNPs mediated hyperthermia of nBCC. The range of the irradiation power was limited to ensure healthy biotissue is not heated to temperatures exceeding 42 • C to avoid damaging effects, such as tissue thermal destruction [78,79].…”

Dual-Wavelength Fluorescence Monitoring of Photodynamic Therapy: From Analytical Models to Clinical Studies

“…The animal study part included the analysis of fluorescence monitoring data obtained in the course of PDT procedures on the intact tissue of rabbit ears and a CT26 tumor model in laboratory mice previously reported in [ 24 , 40 ]. The animal studies were approved by the Ethics Committee of Privolzhsky Research Medical University (Protocol #7, 3 July 2017).…”

Efficiency of direct photoinduced generation of singlet oxygen at different wavelengths, power density and exposure time of laser irradiation

“…1,[3][4][5][6][7] Furthermore, the production of 1 O 2 is the essential stage of photodynamic therapy (PDT) used in the treatment of cancer, bacterial infections, and some other pathologies. [8][9][10][11] It is obvious that the potential toxicity of 1 O 2 to pathological as well as healthy tissues requires determining the optimal dose of irradiation that provides the desired physiological action of 1 O 2 with the minimum possible side effects. 12 This is especially important for the direct optical generation of 1 O 2 , which is characterised by less selectivity due to the absence of a photosensitiser selective accumulation in exact tissue (for example, in a tumour).…”