Technology assessment of new biodegradable poly(R-3-hydroxybutyrate-co-1,4-butylene adipate) copolymers for drug delivery

New biodegradable biomaterials are attracting a huge interest as alternative to conventional polymers used in the field of drug delivery. In this work, we evaluated the ability of new biocompatible and biodegradable polyesters to form nanoparticles (NPs), and tested their potential carrier properties for controlled release of hydrophilic or lipophilic compounds. Multiblock copolymers derived from poly(R-3-hydroxybutyrate) and poly(1,4-butylene adipate) by microwave-assisted transesterification, having different chemical and physicochemical properties were tested. Nanoprecipitation was applied to obtain NPs with a homogenous size distribution. Oil Red O and calcein were encapsulated as lipophilic and hydrophilic probes, evaluating NP mean size and size polydispersity, surface charge, encapsulation efficiency, and release profile. The release curves were fitted into mathematical models to investigate the release mechanism. NPs stability appeared to be strictly related to storage conditions. The NPs were also successfully autoclaved and their mucoadhesive behavior was assessed by a “mucin-particle method.” © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47233.