A series of monodisperse amphiphilic diblock copolymers containing a high-density of covalently linked indomethacin as the hydrophobic block and pendant hexaethylene glycol monomethyl ether as the hydrophilic block have been synthesized from ring-opening metathesis polymerization (ROMP) using Cl 2(PCy 3) 2Ru=CHPh. Dynamic light scattering (DLS), transmission electron microscopy (TEM), and 1H NMR spectroscopy have been used to investigate the directed-assembly of these polynorbornene-based copolymers into polymeric nanoparticles in aqueous media as a function of copolymer composition, concentration, and degree of polymerization. The block copolymers formed micelle-like aggregates in the aqueous phase with mean diameters ranging from 993 ± 270 nm to 94 ± 14 nm by TEM. In general, the aggregate size decreased as the overall copolymer length decreased. After incubation in an acidic environment (pH = 3) at 37 °C for 48 h, 20% of the indomethacin was released from the nanoparticles.
ASJC Scopus subject areas
- Materials Chemistry