Thermosensitive PEG-based hydrogels for drug release and tissue engineering

Biodegradable thermogelling copolymers have a great potential in drug release and tissue engineering. These injectable materials can be implanted in the human body with minimallyinvasive surgery or be used in pharmaceutical formulations in combination with different drugs. Thermogelling materials offer several advantages over chemical hydrogels: they do not require photo irradiation, organic solvents or crosslinking agents, and do not release heat during polymerization, avoiding denaturation of incorporated Active Pharmaceutical Ingredients and damage surrounding cells and tissues. In this work, various formulations consisting of proprietary polyurethane copolymers have been developed and the sustained release of therapeutic agents from these matrices has been demonstrated. For instance a series of PEG based polyurethanes were synthesized and characterized. Different compositions and media (water, PBS, DMEM) were tested and formulations showing sol-gel transition close to physiological temperature were selected for the encapsulation of drugs and cells. Paclitaxel, one of the most potent anti-neoplastic drugs, was encapsulated in the gel, showing a controlled release up to 7 days. These results are expected to open up new perspectives in the treatment of localized tumors, such as prostate or brain tumors, where long-lasting therapy may be obtained by a single injection, reducing patient's discomfort and improved outcome