CC BY
10ALT'22
BIOMEDICAL PHOTONICS
B-I-6
Laser drug delivery by radiation of Vis and IR lasers: efficacy and spectral study
Belikov Andrey, Fedorova Yulia, Smirnov Sergey, Kozlova Anastasia
ITMO University, 49 Kronverksky Pr., 197101, Saint Petersburg, Russia Main author email address: avbelikov@gmail.com
Lasers are widely used in modern medicine, including dermatology. The structures of the skin and nails are a serious barrier to most topical medicines. Chemical, physical, and mechanical methods can be used to improve the efficacy of local drug delivery. The use of laser radiation can be an effective and painless physical method for biological tissue microporation and drug delivery. In this case, Vis and IR lasers can be used for microporation, the radiation of which is effectively absorbed by the chromophores of skin and nails (water, proteins, etc.). There are passive and active laser drug delivery. During passive delivery, water-based drugs penetrate into microporated tissue extremely slow due to the high surface tension coefficient [1]. The penetration rate of water-based drugs can be significantly increased with active laser delivery, for example, due to the action of laser-induced hydrodynamic processes occurring in an aqueous solution [2]. One of the most common dermatological problems is a fungal infection. For the treatment of fungal infection, systemic and local drugs are used, including chlorine-containing photodynamic drugs. The combination of laser microporation and the delivery of such photosensitizing drugs with photodynamic action can significantly increase the efficacy of the treatment of fungal diseases. In this case, it should be considered that laser radiation can affect the conformational state of the photodynamic drug during the delivery and change its photodynamic efficacy [3]. In this regard, it is relevant to study the processes of microporation and active delivery of modern chlorine-containing photosensitizing drugs to the skin and under the nail plate, as well as to study the conformational states of these drugs after exposure to Vis and IR laser radiation and photodynamic exposure. In our study we investigate photodynamic drugs «Chloderm 660» and «Chloderm 660 with hyaluronic acid» (Russia).
For in vitro microporation of human nail plates and chicken skin and laser delivery of the drugs, laser radiation with wavelengths of 405 nm (average power up to 1 W, exposure time up to 1 s), 450 nm (average power up to 2 W, exposure time up to 1 s) and 2810 nm (average power up to 0.4 W, pulse duration of 270 ^s, exposure time up to 1 s) was used. Optical microscopy was used to study the rate and efficiency of nail plate and skin microporation by laser radiation with and without a layer of the drug of various thicknesses deposited on nail surface. The ablation efficiency increased nonlin-early with an increase in the power of laser radiation with wavelengths of 405 nm, 450 nm and 2810 nm, and decreased with an increase in the exposure duration.
The active delivery of the photosensitizing drugs and their aqueous solutions with different concentrations (0.65 ^ 90 %) by laser radiation with the same parameters as during microporation was studied. During delivery, various effects were observed in photodynamic preparations as a result of laser exposure, including hydrodynamic processes stimulating active delivery of preparations through a micropore created during laser microporation of a biological tissue. It was established that the rate of active laser delivery of the studied drugs decreases with an increase in the concentration of the drug in water. Extinction spectra of 5 % aqueous solutions the drugs before and after laser exposure to radiation with wavelengths of 405 nm, 450 nm, 2810 nm and photodynamic exposure with a wavelength of 654 ± 10 nm were studied in the spectral range 200^900 nm. The influence of laser and photodynamic effects on the conformational state of chlorin e6 in the photodynamic drugs was evaluated. The range of radiation parameters of Vis and IR lasers, which leads to a change in the extinction spectra and the conformational state of the studied drugs, was determined.
The research was supported by Russian Science Foundation (project No. 22-25-00468).
[1] A. V. Belikov et al., Er: YLF-laser microperforation of the nail plate for drug delivery, Saratov Fall Meeting 2017: Optical Technologies in Biophysics and Medicine XIX, vol.10716, pp.107160X, (2018).
[2] A.V. Belikov et al., Multi-beam laser-induced hydrodynamic shock waves used for delivery of microparticles and liquids in skin, Lasers in Surgery and Medicine, vol.47, pp.723-736, (2015).
[3] A. V. Belikov, S. N. Smirnov and A. D. Tavalinskaya, Laser Delivery and Spectral Study of a Chlorine-Containing Drug for the Treatment of Onychomycosis at Sequential Laser (X= 2810 nm) and Photodynamic (X= 656±10 nm) Impact, Optics and Spectroscopy, pp.1-9, (2021).
