Preparation of injectable forms of immobilized protein drugs using UV-curable gelatin derivatives

Photo-immobilization is an effective technique for loading protein-based drugs in a natural polymer, which can help maintain the drugs’ effects constantly. An ideal drug immobilization material is a natural polymer with biocompatibility, biodegradability, and low toxicity, which can be applied as a medical material. However, current formulations have limitations such as rapid degradation of loaded protein drugs by the enzymes in the body, thus reducing the drugs’ therapeutic efficiency. In the present study, we aimed to develop an injectable formulation as a drug delivery system using gelatin, a natural polymer that is safe for use in humans and meets the criteria for injectable derivatives. Gelatin was functionalized with UV-irradiated azidophenyl to prepare particles for the immobilization of a protein. We confirmed the immobilization of fluorescent-conjugated bovine serum albumin by fluorescent microscopy. Azidophenyl gelatin (Az-gelatin) showed no cytotoxicity, and the epidermal growth factor immobilized in the particle maintained its function of promoting cell proliferation for up to 48h. Based on these characteristics, UV-curable Az-gelatin is expected to have widespread applications in the medical field.