Random co-polymers based on the poloxamer Bayfit® 10WF15 for biomedical applications

Random co-polymers were prepared from the poloxamer Bayfit(®) 10WF15 and their thermal and biological properties analyzed. The poloxamer was characterized, functionalized with methacrylate groups (Bayfit-MA) and further co-polymerized with 2-hydroxyethyl methacrylate (HEMA) with Bayfit-MA feed contents of 1, 5 and 10 wt%. Co-polymers were partially soluble in organic solvents and exhibited a single glass transition temperature indicative of a random monomer distribution in the macromolecular chains. In thermogravimetric studies the co-polymers showed two degradation stages, around 210 and 350 °C, respectively. The thermosensitive behaviour of the poloxamer was studied by turbidimetry. Cloud point temperatures of aqueous solutions of Bayfit(®) 10WF15 (0.5-5 wt%) ranged from 15 to 18 °C and for Bayfit(®) 10WF15 methacrylate (0.5-1 wt%) from 6 to 7 °C. DSC thermograms of hydrated co-polymers showed the typical endothermic peaks with phase transition temperatures close to that of physiological medium. The biocompatibility of initial poloxamer and derivatives was analyzed with human fibroblasts cultures. The IC(50) value of Bayfit(®) 10WF15 was 1.4 mg/ml. Cellular extracts of the co-polymers were not cytotoxic and cellular proliferation and DNA content depended on co-polymer composition.