ABSTRACT
Liver fibrosis is a major disease that affects human health. Currently,drugs used for the treatment of hepatic fibrosis have such problems as low drug solubility,lack of liver specificity and possible occurrence of side-effects. In order to improve the anti-fibrosis therapeutic efficacy,various nano-drug delivery systems and targeting strategies are explored in liver fibrosis therapy. This review summarizes the drug delivery systems and targeting strategies that have been applied to liver fibrosis therapy in recent years from the types of carriers and modified ligands,which serve as a basis of designing safe and effective drug delivery systems for liver fibrosis therapy.
ABSTRACT
Biodegradable polyamines have long been studied as potential recombinant viral gene vectors. Spermine (SPE) is an endogenous tetra-amine with excellent biocompatibility yet poor gene condensation capacity. We have previously synthesized a polyspermine based on SPE and poly(ethylene glycol) (PEG) diacrylate (SPE-alt-PEG) for enhanced transfection performance, but the synthesized SPE-alt-PEG still lacked specificity towards cancer cells. In this study, folic acid (FA) was incorporated into SPE-alt-PEG to fabricate a targeted gene delivery vector (FA-SPE-PEG) via an acylation reaction. FA-SPE-PEG exhibited mild cytotoxicity in both cancer cells and normal cells. FA-SPE-PEG possessed higher transfection efficiency than PEI 25 K and Lipofectamine(®) 2000 in two tested cancer cell lines at functional weight ratios, and its superiority over untargeted SPE-alt-PEG was prominent in cells with overexpressed folate receptors (FRs). Moreover, in vivo delivery of green fluorescent protein (GFP) with FA-SPE-PEG resulted in highest fluorescent signal intensity of all investigated groups. FA-SPE-PEG showed remarkably enhanced specificity towards cancer cells both in vivo and in vitro due to the interaction between FA and FRs. Taken together, FA-SPE-PEG was demonstrated to be a prospective targeted gene delivery vector with high transfection capacity and excellent biocompatibility.
ABSTRACT
@#To investigate the cellular immunogenicity of influenza vaccine liposomes dry powder using the film-dispersion and freeze-thawing. Mice were divided into the non-liposomal influenza vaccine group, film-dispersion prepared liposomal influenza vaccine group, freeze-thawing lyophilized influenza vaccine liposome group, positive control group and negative control group(n=5). 6 μg of hemagglutinin of H1N1 subtype per mouse was delivered tracheally to the mice of lyophilized liposomes groups, with the same dose for non-liposomes intraperitoneally delivered groups as the positive control, and PBS intraperotoneal injection group as the negative control. After 28-day of immunization, the proliferationofsplenic lymphocytes was detected by MTT assay; CD4+cell and CD8+cell were analyzed by flow cytometry. The dry powder of influenza vaccine liposomes prepared by the above two methods, both induce cellular immunity, with no significant difference in the induced on immunogenicity between the prepared products(P< 0. 05). The results showed that freeze-thawing method is feasible in the preparation of vaccine liposomes, leading to the attenuated live vaccine liposome preparation.