Smart nanoparticles improve therapy for drug-resistant tumors by overcoming pathophysiological barriers.

The therapeutic outcome of chemotherapy is severely limited by intrinsic or acquired drug resistance, the most common causes of chemotherapy failure. In the past few decades, advancements in nanotechnology have provided alternative strategies for combating tumor drug resistance. Drug-loaded nanoparticles (NPs) have several advantages over the free drug forms, including reduced cytotoxicity, prolonged circulation in the blood and increased accumulation in tumors.

Synthesis and properties of O-carboxymethyl chitosan/methoxy poly(ethylene glycol) graft copolymers.

O-carboxymethyl chitosan/methoxy poly(ethylene glycol) graft copolymers (OCMCS-g-MPEGs) with different degrees of substitution (DS) were synthesized by reductive N-alkylation of chitosan with poly(ethylene glycol) aldehyde. The properties of OCMCS-g-MPEGs, including the solubility, structure, hydrodynamic behaviors, isoelectric point (IEP) and interaction with water-soluble chitosan, were investigated. As a PEGylated polyampholyte, OCMCS-g-MPEGs can resolve in water over all pH range and the pH value at IEP (pH(IEP)) decreases when DS increases.

Characterization and in vitro degradation of poly(octadecanoic anhydride).

Poly(octadecanoic anhydride) (POA) has been prepared by melt polycondensation of octadecanoic diacid. POA was characterized by Fourier-transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and wide angle X-ray diffraction (WAXD). The results of in vitro degradation and SEM micrographs show that the erosion process of POA is neither bulk nor perfect surface erosion but rather has elements of both in phosphate buffer at 37 degrees C.

[Function of nanoparticles in transdermal and transmucosal drug delivery systems].

Nanoparticles had received much attention in the development of new kind of pharmaceutical formation because of the special nano-effectivity. Recently, some studies discovered the special functions of the nanoparticles in transdermal and transmucosal drug delivery systems. Even though the acting mechanism of the nanoparticles in these drug delivery systems are not known, these discoveries of the special function of the nanoparticles provide new developing prospect to the drug delivery systems.

[Studies on paclitaxel-loaded nanoparticles of amphiphilic block copolymer].

Aim: To investigate the paclitaxel-loaded nanoparticles of poly(ethylene glycol)-b-poly(D,L-lactic acid) amphiphilic diblock copolymer (PMT).

Methods: PMT was prepared by solid dispersion technique. The average size and size distribution were determined by dynamic light scattering (DLS).