An Amphiphilic Nanocarrier Based on Guar Gum-graft-Poly(ε-caprolactone) for Potential Drug-Delivery Applications

Amphiphilic guar gum grafted with poly(e-caprolactone) (GG-g-PCL) was fabricated as a drug-delivery carrier using microwave irradiation. The structure of the GG-g-PCL co-polymer was characterized by H-1-NMR spectroscopy. By microwave irradiation, GG-g-PCL with high grafting percentage (>200%) was obtained in a short reaction time. The GG-g-PCL co-polymer is capable of self-assembling into nanosized spherical micelles in aqueous solution with the diameter of around 75-135 nm and 60-100 nm, as determined by DLS and TEM, respectively. The critical micelle concentration (CMC) of GG-g-PCL was found to be approx. 0.56 mg/l in a phosphate buffer solution. The drug-release profile showed that the GG-g-PCL micelles provided an initial burst release followed by a sustained release of the entrapped hydrophobic model drug, ketoprofen, over a period of 10-68 h. Under physiological conditions, the GG-g-PCL co-polymer hydrolytically degraded into lower-molecular-weight fragments within a 7-week period. These results suggest that the GG-g-PCL micelles could be used as a nanocarrier for in vitro controlled drug delivery. (C) Koninklijke Brill NV, Leiden, 2010