Enhanced In Vitro Antitumor Efficacy and Strong Anti-Cell-Migration Activity of a Hydroxycamptothecin-Encapsulated Magnetic Nanovehicle

A 10-hydroxycamptothecin-encapsulated magnetic nanovehicle (HEMN) was fabricated by coencapsulating Fe3O4 nanoparticles and 10-hydroxycamptothecin (HCPT) into a micelle core self-assembled from the amphiphilic copolymer methoxy-poly(ethylene glycol)-poly(D,L-lactide-co-glycolide) through a facile dialysis method. A satisfactory drug-loading content of (9.03 +/- 0.67)% and a relatively high encapsulation efficiency of (53.52 +/- 6.46)% were achieved. In vitro drug release was performed by membrane dialysis and a pH-dependent release behavior was observed. In comparison with free HCPT dissolved in dimethylsulfoxide, HEMNs showed a greatly improved in vitro antitumor efficacy against three different human cancer cell lines-HeLa, A549, and HepG2- and lower IC50 values were measured. The mechanism of cell death was investigated, and it was clearly demonstrated that the apoptosis process was triggered. An in vitro wound-healing assay and a transwell assay indicated that HEMNs exerted much stronger activity in inhibiting HeLa cell migration. The cellular uptake of HEMNs in a desired area can be significantly enhanced by an external magnetic field. These results demonstrate HCPT-encapsulated magnetic nanovehicles might have important potential in clinical applications for inhibiting tumor metastasis and for targeted drug delivery.