Chitosan-functionalized graphene oxide as a nanocarrier for drug and gene delivery.

The covalent functionalization of graphene oxide (GO) with chitosan (CS) is successfully accomplished via a facile amidation process. The CS-grafted GO (GO-CS) sheets consist of about 64 wt.% CS, which imparts them with a good aqueous solubility and biocompatibility.

Thermo-responsive association of chitosan-graft-poly(N-isopropylacrylamide) in aqueous solutions.

A comb-like dual hydrophilic graft chitosan copolymer, chitosan-graft-poly(N-isopropylacrylamide) (CS-g-PNIPAM), was synthesized by means of atom transfer radical polymerization (ATRP) and click chemistry. The thermo-responsive association behavior of the copolymer in dilute aqueous solutions has been investigated by laser light scattering (LLS), zeta potential, and transmission electron microscopy (TEM). The core-shell structured micelles with the hydrophobic PNIAPM as a core and the hydrophilic CS as a shell were formed at low pH (<4) and high temperature (>32 degrees C), whereas the obtained micelles became large aggregates and precipitated in alkaline solutions (pH > 7).

Micelle-like nanoparticles of star-branched PEO-PLA copolymers as chemotherapeutic carrier.

Four-armed (star-branched) block copolymers of l-PLA and PEO were synthesized using ring opening polymerization with different LA/EO ratio. Micellar aggregates were prepared from these block copolymers and characterized. Some surface segregation of PEG was found : the extent depends on the state of the material (whether it is in film or particle form), as well as on molecular geometry.

Micelle-like nanoparticles of PLA-PEG-PLA triblock copolymer as chemotherapeutic carrier.

Triblock copolymer PLA-PEG-PLA were synthesized using ring opening polymerization with different LA/EG ratio. Micellar aggregates were prepared from these block copolymers and characterized. The degradation characteristics of selected copolymers were assessed in both micellar and film forms.

Structure formation in injectable poly(lactide-co-glycolide) depots. II. Nature of the gel.

The benzyl benzoate solutions of poly(D,L-lactide-co-glycolide), a random oriented synthesized copolymer with L/G ratio of 50:50, have been shown to form gels during aging and upon injection into buffer or water. The gelation properties influence drug release kinetics for these injectable, depot-forming solutions. In this article, we report on the mechanism of gelation.