Chemotherapeutic Delivery from a Self-Assembling Peptide Nanofiber Hydrogel for the Management of Glioblastoma

Abstract

Abstract

Purpose Localized chemotherapy has gained significant impetus for the management of malignant brain tumors. In the present study, we appraised the versatility of an in-situ gel forming self-assembling peptide, ac-(RADA)4-CONH2, as a biocompatible delivery depot of the chemotherapeutic drug doxorubicin (DOX) and the anticancer agent curcumin (CUR), respectively.

Methods The morphology and mechanical properties of ac-(RADA)4-CONH2 were assessed with scanning electron microscopy (SEM) and rheological studies. The in vitro drug release from ac-(RADA)4-CONH2 was monitored in phosphate-buffered saline pH 7.4. Distribution of the fluorescent actives within the peptide matrix was visualized with confocal laser scanning microscopy (CLSM). The in vitro biological performance of the ac-(RADA)4-CONH2-DOX and ac-(RADA)4-CONH2-CUR was evaluated on the human glioblastoma U-87 MG cell line.

Results SEM studies revealed that the ac-(RADA)4-CONH2 hydrogel contains an entangled nanofiber network. Rheology studies showed that the more hydrophobic CUR resulted in a stiffer hydrogel compared with ac-(RADA)4-CONH2 and ac-(RADA)4-CONH2-DOX, due to the interaction of CUR with the hydrophobic domains of the peptide nanofibers as confirmed by CLSM. In vitro release studies showed a complete DOX release from ac-(RADA)4-CONH2 within 4 days and a prolonged release for ac-(RADA)4-CONH2-CUR over 20 days. An increased cellular uptake and a higher cytotoxic effect were observed for ac-(RADA)4-CONH2-DOX, compared with DOX solution. Higher levels of early apoptosis were observed for the cells treated with the ac-(RADA)4-CONH2-CUR, compared to CUR solution.

Conclusions The current findings highlight the potential utility of the in-situ depot forming ac-(RADA)4-CONH2 hydrogel for the local delivery of both water soluble and insoluble chemotherapeutic drugs.