New biomaterials from renewable resources – amphiphilic block copolymers from δ-decalactone

The synthesis of polymers for biomedical applications via environmentally benign routes and with sustainable feedstocks is an area of intense interest. Here we describe the synthesis, characterisation and drug carrier potential of novel polymeric materials obtained from a non-toxic, low cost and easily accessible renewable monomer, δ-decalactone. A range of different polymers and copolymers of δ-decalactone was synthesised under mild reaction conditions using organic and enzymatic catalysts. Amphiphilic block copolymers of δ-decalactone with poly(ethyleneglycol) (PEG) and terpolymers with poly(pentadecalactone) were shown to self-assemble into micelles and a hydrophobic dye (Nile Red) was incorporated inside the micellar cores via a nanoprecipitation method. The encapsulation properties of the polymeric micelles were explored using Amphotericin B (AmpB) as a model drug. A comparative loading study of AmpB in PEG- b -poly(δ-decalactone) and in PEG- b -poly(ε-caprolactone) micelles demonstrated a higher loading of AmpB in the δ-decalactone co-polymer. In vitro release studies of AmpB from the polymer micelles demonstrated sustained release of AmpB for up to 8 days. A preliminary hydrolytic degradation and cytotoxicity study indicated that the block co-polymer micelles are biodegradable and exhibit low toxicity. These data suggest that the δ-decalactone copolymers are of promise for further development towards biomedical applications.