Bioreducible Peptide-Dendrimeric Nanogels with Abundant Expanded Voids for Efficient Drug Entrapment and Delivery.

Dendrimer-based nanoplatforms have exhibited wide prospects in the field of nanomedicine for drug delivery, without great success due to many predicaments of cytotoxicity, high cost, and low yield. In this work, we report a feasible strategy on dynamic cross-linkings of low-generation peptide dendrimers into bioreducible nanogels for efficient drug controlled release. With a facile fabrication, the disulfide cross-linking of biocompatible peptide dendrimers successfully possess well-defined and stable nanostructures with abundant expanded voids for efficient molecular encapsulation. More importantly, high reducing condition is capable of triggering the cleavage of disulfide bonds, the disintegration of peptide-dendrimeric nanogels, and stimuli-responsive release of guest molecules. The bioreducible nanogels improve antitumor drug internalization, contribute to endosomal escape, and realize intracellular drug controlled release. The doxorubicin-loaded nanogels afford high antitumor efficiency and reduce the side effects to BALB/c mice bearing 4T1 tumor. Therefore, dynamic cross-linkings of low-generation dendrimers into smart nanogels will be an alternative and promising strategy to resolve the dilemmas of current dendrimer-based nanocarriers as well as develop innovative nanoplatforms.