Folate-conjugated polyspermine for lung cancer-targeted gene therapy

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.

A comparative study on two different biopsy techniques in the diagnosis of pancreatic cancer / 中华普通外科杂志

Objective To compare wedge biopsy and disposable automatic biopsy gun biopsy for the diagnosis of pancreatic cancer. Methods The clinical data of 217 patients with unresectable pancreatic cancer undergoing palliative operation and biopsy were retrospectively analyzed in our hospital from March 25,2006 to March 25,2011.Group A(wedge biopsy) consisted of 120 cases and B( disposable automated biopsy gun biopsy) of 97 cases.The success rate of biopsy,the positive rate of biopsy,the accuracy of diagnosis and the incidence of postoperative complications were calculated. Results The success rate,positive rate,diagnostic accuracy and the incidence of postoperative hemorrhage of group A and B were 100％,97.5％,97.5％,1.7％ and 100％,99％,99％,1.0％,respectively ( all P ＞ 0.05 ).The incidence of postoperative pancreatic leakage in group A and B were 11.7％ and 2.1％ (P =0.007 ).Conclusions Intra-operative biopsy for the diagnosis of pancreatic cancer using disposable automated biopsy gun biopsy has significantly decreased the incidence of post-biopsy pancreatic leakage as compared with wedge biopsy.