Aliphatic polycarbonates and polyesters are two important classes of biocompatible and biodegradable materials widely used for drug delivery and tissue engineering applications. Polycarbonates are mostly known for their good mechanical properties and for their minimally toxic and non-acidic degradation products.1-4 Certain polyesters are interesting as biodegradable and bioassimilable materials. Nevertheless, the growing need for increasingly versatile biomaterials has spurred the development of functional versions of traditionally used polymers, including polycarbonates and polyesters, to enable facile tuning of their physicochemical and biological properties by installation of sites for covalent conjugation.
We have demonstrated the effectiveness of a dual activated organocatalytic system−consisting of DBU and a thiourea− for the ring-opening polymerization of PTO (9-phenyl-2,4,8,10-tetraoxaspiro[5,5]undecan-3-one) and its copolymerization with D,L-lactide (DLLA). PTO is a functional derivative of trimethylene carbonate that allows installation of 1,3-diols along the polycarbonate backbone. Polymers with controllable molecular characteristics were achieved by optimizing carbonate conversion, monomer:catalyst ratio, and the relative concentration of carbonate in the copolymer. These biodegradable amphiphiles were used as stabilizers of hydrophobic solutes in water, formed via flash nanoprecipitation, and differences in nanoparticle properties were discussed in terms of hydrophobic block chemistry. Enabled by the installation of reactive handles, these biomaterials should find broad applications as scaffolds for the construction of polymeric structures with increasingly complex architecture and function.
Related
- Organocatalytic Copolymerization of a Cyclic Carbonate Bearing Protected 2,2-bis(hydroxymethyl) Groups and d,l-lactide. Effect of Hydrophobic Block Chemistry on Nanoparticle Properties (Macromolecules, 2013, 46 (15), pgs. 5871-5881)