Antitumor activities of emulsion electrospun fibers with core loading of hydroxycamptothecin via intratumoral implantation

摘要

Emulsion electrospinning was used in the present study to prepare core-sheath structured fibers with core-loading of hydroxycamptothecin (HCPT), and their antitumor activities were evaluated both in vitro on cancer cell lines and in vivo on tumor bearing mice via intratumoral implantation. Compared with our previous investigation on blend electrospun fibers, the addition of 2-hydroxypropyl-β-cyclodextrin (HPCD) and the preferential formation of HPCT/HPCD inclusion complexes resulted in significantly faster HCPT release from and higher degradation rate of emulsion electrospun fibers. The core-sheath structure led to around 93% of lactone form remaining after emulsion electrospinning and incubation in buffer solutions for over one month. In vitro cytotoxicity tests on HCPT-loaded electrospun fibers indicated over 20 times higher inhibitory activity against HepG2 cells than free HCPT during 72 h incubation. Hepatoma H22 cells were subcutaneously injected into Kunming mice to form solid tumors for in vivo tests on the antitumor efficacy. Based on the tumor volume, survival rate and body weight changes, HCPT-loaded fibers indicated superior in vivo antitumor activities to and fewer side effects than free HCPT. The histopathological staining and immunohistochemical examinations of caspase-3 expression indicated more necrosis and apoptosis induced by HCPT-loaded fibers. The above results demonstrate the potential use of emulsion electrospun fibers as drug carriers for local treatment of solid tumors.