Assessment of cytotoxicity and tumor uptake of composites of hyaluronic acid and gold particles

One of the ways to improve efficiency of radiation therapy is to use binary radiation therapy modalities, including photon capture therapy (PCT). Though PCT has a number of advantages: it is effective for treatment of radioresistant tumors, produces sparing effect on surrounding normal tissues, its further development depends to a large extent on availability of agents exhibiting high tumor uptake and low cytotoxicity. Composites of hyaluronic acid and gold particles are promising compounds for PCT. The article presents results of research into feasibility of using composites of melanin-modified hyaluronic acid salt and gold particles containing different amount of gold for photon-capture therapy. The in vivo study was carried out in B-16 melanoma - bearing male mice of F1 (CBAxC57Bl/6) strain, the in vitro study was carried out using B-16 melanoma cells culture. The composites with the gold content 1.5 or 2.2 mg in 0.1ml of solution were injected into the tumor in 12 days after the tumor cells inoculation. Gold uptake and excretion was measured during 3 hours following the injection. In 30 minutes gold uptake in the tumor was 17% of the total amount of the injected composite. We think that this is the most suitable time to deliver photon capture therapy. In in vitro studies minor effect of gold in concentration of 62.5 and 125 mcg in 1 ml of culture medium on inhibition of proliferation of B-16 melanoma cells was observed. Further study of the composites of melanin-modified hyaluronic acid salt and gold particles for improving efficiency of photon-capture therapy is needed.