Entrapment and Delivery of Doxorubicin: Employing a Permeable Lipopeptide-Based Hydrogel as an Efficient Cationic Binder.

Lipopeptides have been the subject of great interest as vehicles for drug delivery, but the potential usage of their biological composites has not been extensively studied. Here, the extracellular lipopeptide composite (ELC) of a lipopeptide-producing bacterium was extracted and examined to deliver doxorubicin (DOX) as a cationic drug. MALDI-TOF mass spectrometry analysis on the lipopeptide moiety of ELC revealed that this hydrogel consists of 13 lipopeptide isomers. Furthermore, scanning electron microscope (SEM) studies showed that the permeability of ELC in acidic pH was significantly more than basic condition. In this study, 81% of DOX was successfully entrapped in ELC and the release of the drug was measured in acidic, neutral, and basic conditions. The results indicated that the release profile of the drug in acidic pH was about 10 and 16 fold more than neutral and basic conditions, respectively. Besides, the toxicity of DOX-conjugated ELC against PBMC cells was more than free DOX, suggesting the adequate drug release from ELC. Since the surrounding environment of tumor cells is often acidic, this pH-sensitive carrier could be a candidate for cancer therapy to improve the exposure of tumor cells to the drugs.