Deformation Response of Biological Phantoms and Cartilaginous Tissue at Laser Exposure

Regeneration of cartilaginous tissue and its shape change at laser exposure can be used as a basis for prospective medical operations, improving patient’s quality of life. The most important criterion of such operations success is a cell survival after laser exposure, therefore reduction of exposure duration and power is an important task at such methods development. Nanoparticles are actively used in medicine, and one of their intended usages is photothermal effect enhancement at laser exposure to biological tissue. However, articular tissue is quite resistant to foreign agents penetration, therefore the study of nanoparticles penetration capability and their impregnation effect is the priority task for achieving the desired medical effect. Optical coherence tomography (OCT) of gel phantoms and cartilaginous tissue of a joint, impregnated with nanoparticles, at laser exposure with erbium fiber laser with length wave of 1.56 μm is performed in this study. Articular cartilaginous tissue sections of three types (intact, with laser damage and after low laser exposure) were impregnated with nanoparticles of Fe₃O₄ for further study using OCT elastography. Increase of deformations, caused by heating of phantoms and tissue, impregnated with nanoparticles, is observed. OCT elastography data indicate the dependence of tissue deformation on previous tissue exposure history. The work substantiates increase of photothermal impact of laser exposure to tissue deformation at various nanoparticles introduction.