Self-assembled nanoparticles based on glycol chitosan bearing hydrophobic moieties as carriers for doxorubicin: in vivo biodistribution and anti-tumor activity.

Self-assembled nanoparticles, formed by polymeric amphiphiles, have been demonstrated to accumulate in solid tumors by the enhanced permeability and retention effect, following intravenous administration. In this study, hydrophobically modified glycol chitosans capable of forming nano-sized self-aggregates were prepared by chemical conjugation of fluorescein isothiocyanate or doxorubicin to the backbone of glycol chitosan. Biodistribution of self-aggregates (300 nm in diameter) was evaluated using tissues obtained from tumor-bearing mice, to which self-aggregates were systemically administered via the tail vein.

Self-assembled nanoparticles based on glycol chitosan bearing 5beta-cholanic acid for RGD peptide delivery.

The synthetic peptide bearing Arg-Gly-Asp (RGD) sequence is considered to specifically bind to alpha(v)beta(3) integrin expressed on endothelial cells in the angiogenic blood vessels, which provides a potential to inhibit the tumor growth. As a carrier for the RGD peptide, hydrophobically modified glycol chitosan (HGC) capable of forming nano-sized self-aggregates was prepared by the chemical conjugation of 5beta-cholanic acid to the main backbone of glycol chitosan. The RGD peptide labeled with fluoresein isothiocyanate (FITC-GRGDS) was loaded into self-aggregates in three different conditions: simple mixing, sonication, and solvent evaporation methods.

Biodistribution and anti-tumor efficacy of doxorubicin loaded glycol-chitosan nanoaggregates by EPR effect.

An in vivo tumor targeting test of glycol-chitosan nanoaggregates was carried out with FITC-conjugated glycol-chitosan nanoaggregates (FTC-GC) and the doxorubicin conjugated glycol-chitosan (GC-DOX). To investigate its biodistribution in tumor-bearing rats, glycol-chitosan was labeled with fluorescein isothiocyanate (FITC), which formed nanoaggregates with a diameter of about 250 nm in aqueous media. GC-DOX nanoaggregates containing acid-sensitive spacers were prepared.

Inhibitory effect of high molecular weight water-soluble chitosan on hypoxia-induced inflammatory cytokine production.

Chitosan is widely used to treat patients with hypoxia-induced diseases such as ischemia, neuronal death, cerebral stroke, and cerebral infarction. Using the ELISA method, we examined the effect of high molecular weight water-soluble chitosan (WSC) on inflammatory cytokine production in the desferrioxamine (DFX, known to mimic hypoxia)-stimulated human mast cell line HMC-1. DFX significantly increased interleukin (IL)-6, IL-8, and tumor necrosis factor (TNF)-alpha production compared with the control in a time-dependent manner (p<0.

CancerB increases production of nitric oxide and tumor necrosis factor-alpha in peritoneal macrophages.

Background: CancerB (CCB, IMSF-5), herbal combination, may be able to stimulate potential toxic mediators such as nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) in isolated mouse peritoneal macrophages.

Methods: NO production was determined by Griess method, and TNF-alpha production by enzyme-linked immunosorbent assay. Amounts of proteins were observed by Western blotting.

Water-soluble chitosan inhibits the production of pro-inflammatory cytokine in human astrocytoma cells activated by amyloid beta peptide and interleukin-1beta.

A chronic inflammatory response associated with beta-amyloid (Abeta) and interleukin-1beta (IL-1beta) is responsible for the pathology of Alzheimer's disease (AD). Astrocytes are predominant neuroglial cells of the central nervous system and are actively involved in cytokine-mediated events in AD. To investigate the biological effect of water-soluble chitosan (WSC), we examined cytotoxicity, production of pro-inflammatory cytokines and inducible nitric-oxide synthase (iNOS) on human astrocytoma cell line CCF-STTG1 stimulated with IL-1beta and Abeta fragment 25-35 (Abeta[25-35]).