Biodegradable and biocompatible multi-arm star amphiphilic block copolymer as a carrier for hydrophobic drug delivery.

Publications // Shaoqin Gong // May 01 2009

PubMed ID: 19428465

Author(s): Aryal S, Prabaharan M, Pilla S, Gong S. Biodegradable and biocompatible multi-arm star amphiphilic block copolymer as a carrier for hydrophobic drug delivery. Int J Biol Macromol. 2009 May 1;44(4):346-52. doi: 10.1016/j.ijbiomac.2009.01.007. Epub 2009 Feb 13. PMID 19428465

Journal: International Journal Of Biological Macromolecules, Volume 44, Issue 4, May 2009

Multi-arm star amphiphilic block copolymers (SABCs) with approximately 32 arms were synthesized and characterized for drug delivery applications. A hyperbranched polyester, boltorn H40 (H40), was used as the macroinitiator for the ring-opening polymerization of epsilon-caprolactone (epsilon-CL). The resulting multi-arm H40-poly(epsilon-caprolactone) (H40-PCL-OH) was further reacted with carboxyl terminated methoxy poly(ethylene glycol) (MPEG-COOH) to form H40-PCL-b-MPEG copolymers. The resulting SABCs were characterized by (1)H NMR spectroscopy and gel permeation chromatography (GPC). The critical aggregation concentration (CAC) of H40-PCL-b-MPEG was 3.8 mg/L as determined by fluorescence spectrophotometry. Below the CAC, stable unimolecular micelles were formed with an average diameter of 18 nm as measured by TEM. Above the CAC, unimolecular micelles exhibited agglomeration with an average diameter of 98 nm. The hydrodynamic diameter of these agglomerates was found to be 122 nm, as measured by dynamic light scattering (DLS). The drug loading efficacy of the H40-PCL-b-MPEG micelles was 26 wt%. Drug release study showed an initial burst followed by a sustained release of the entrapped hydrophobic model drug, 5-fluorouracil, over a period of 9-140 h. These results indicate that the H40-PCL-b-MPEG micelles have great potential as hydrophobic drug delivery carriers.