Gonarthritis photodynamic therapy with chlorin e6 derivatives

The new methods of osteoarthritis treatment are in constant demand due to the complexity of the early diagnosis and therapy. Specific features of Сhlorin e6 derivative (Ce6) accumulation in knee joint tissues and the efficiency of photodynamic therapy (PDT) of gonarthritis were studied.

The experimental research was conducted on the model of posttraumatic gonarthritis on rabbits. The analysis of dynamics of change of Ce6 concentration in tissues of a knee joint was carried out by the method of fluorescent diagnostics. The intra-joint PDT was carried out using 662nm laser with energy density of 120-150J/cm(2) and a sapphire diffuser. An analysis of slices was conducted to confirm the anti-inflammatory effect through apoptosis.

The method of fluorescent spectroscopy revealed that the highest amount of Ce6 was accumulated in the synovial membrane of a damaged knee joint 2.5h after its intravenous introduction. On 14th day after gonarthritis modeling but before PDT the synovial membrane showed signs of synovitis. On 21st day after PDT the synovial membrane possessed noticeable villous structure, and no cells of inflammatory nature were observed.

Fluorescent diagnostics in knee joint tissues can be used in clinical practice of gonarthritis before, during and after PDT for monitoring the Ce6 accumulation and for treatment control. Optimal radiation energy density was determined to be 150J/cm(2). In the studied time intervals (5-25min) no dependency of PDT effect on irradiation time at the same energy density was observed. The analysis of results of clinical and morphological research shows that PDT is a low-invasive method of gonarthritis treatment with a high degree of efficiency and selectivity.