Microparticles for drug delivery based on functional polycaprolactones with enhanced degradability: loading of hydrophilic and hydrophobic active compounds.

Microparticle drug carriers made of biodegradable functional polyesters were produced. The polyesters consist of a poly(ε-caprolactone) backbone bearing pendant acryloyloxy and methacryloyloxy groups. Stable microparticles were prepared via an oil/water emulsion-solvent evaporation technique eventually combined with a simultaneous crosslinking procedure. Crosslinked particles were obtained via photo-crosslinking and Michael type addition using diamines as crosslinking agents. Encapsulation of a hydrophobic fluorescent dye and a hydrophilic protein, as model drugs, were performed and confirmed by optical microscopy and Raman spectroscopy. The presence of the functional groups allow for not only the tuning of the degradation rate, but also for further processing and (bio)functionalization.