Amphiphilic Polymer Nanoparticles: Characterization and Assessment as New Drug Carriers

Abstract

An amino-acid-based hydrophobically modified biocompatible copolymer, poly[(sodium N-acryloyl-L-valinate)-co-(N-octylacrylamide)] was synthesized and characterized. Techniques such as fluorescence probes, DLS, and TEM were used to investigate its aggregation behavior in aqueous solution. The copolymer was observed to form micellar aggregates having diameters in the nanometer range in aqueous solution (pH = 8) through inter-chain hydrophobic association. This behavior was found to be similar to that of poly[(sodium N-acryloyl-L-valinate)-co-(N-dodecylacrylamide)]. The compact micellar nanostructures were observed to be stable with respect to changes of pH and temperature. The encapsulation and release of griseofulvin, a hydrophobic model drug, was studied.

Amino acid based amphiphilic copolymer micelles as carriers of non-steroidal anti-inflammatory drugs: Solubilization, in vitro release and biological evaluation

“…A good correlation coefficient (R 2 = 0.99) was observed for both KTP and NPX. The resulting release exponent value (n) < 0.5 confirmed diffusion based drug release mechanism for this polymeric system (Dutta et al, 2009b). For both the drugs, it was observed that the kinetic constant k decreased upon increase of pH from 5.0 to 7.4 suggesting faster release (about 1.5 times) at pH 7.4.…”

“…Solubilization studies were carried out following our previous report (Dutta et al, 2009b). Briefly, the NSAIDs were dissolved in chloroform in screw-caped test tube.…”

“…In addition, the copolymers exhibit a pH-induced conformational transition near physiological pH. These copolymers were also found to be particularly interesting in increasing the solubility of poorly water-soluble drug griseofulvin (Dutta et al, 2009b). For griseofulvin, the solubilization capacity (S cp ) of the HMPs was found to be ca.…”

“…For griseofulvin, the solubilization capacity (S cp ) of the HMPs was found to be ca. 11.5-27.7 mg/g, which is quite large compared to that of micelle-forming neutral surfactants [e.g., Tween 80 (3.4 mg/g), and Creomphor EL (2.6 mg/g)] and triblock copolymers (M n ∼ 5000-7000 g/mol) of ethylene oxide and phenylglycidyl ether (∼4.0-17.8 mg/g) (Dutta et al, 2009b). Encouraged by the preliminary results we have extended the work to other pharmaceutically active compounds.…”

Amphiphilic PHA–mPEG copolymeric nanocontainers for drug delivery: Preparation, characterization and in vitro evaluation

“…Most of the hydrophobic drugs when administered to the body are often precipitated and degraded in the blood stream without reaching the target zone, and thus cause severe side affects (Dutta et al, 2009). TQ, the major biologically active component isolated from a traditional medicinal herb, Nigella sativa Linn., is a potential chemopreventive and chemotherapeutic compound (El-Mahdy et al, 2005).…”