Amphiphilic Poly(N-vinylpyrrolidone) Biocomposites with Bortezomib and DR5-Selective TRAIL Variants: A Promising...

A promising strategy for pancreatic cancer therapy involves developing nanocarriers capable of simultaneously delivering various antitumor substances with diverse physicochemical properties, often resulting in synergistic effects. In the present work, novel biocomposites were developed using amphiphilic N-vinylpyrrolidone polymer incorporating bortezomib (BTZ) and modified with either the DR5-selective TRAIL cytokine (DR5-B) or its fusion with the iRGD effector peptide (DR5-B-iRGD), resulting in AmphPVP-BTZ-DR5-B and AmphPVP-BTZ-DR5-B-iRGD formulations. The release of BTZ was most extensive at acidic pH 5.6, mimicking endolysosomal compartments, while at near-neutral pH 7.4 and alkaline pH 8.2 the release was slower and less complete, indicating a smart pH-responsive behavior suitable for triggered release in the tumor microenvironment. Both AmphPVP-BTZ-DR5-B and AmphPVP-BTZ-DR5-B-iRGD significantly inhibited the growth of pancreatic adenocarcinoma cell lines PANC-1, BxPC-3, and MIA PaCa-2 and induced more rapid internalization of the DR5 receptor in MIA PaCa-2 cells than unmodified particles and free DR5-B or DR5-B-iRGD. Importantly, AmphPVP-BTZ-DR5-B-iRGD exhibited a more pronounced DR5 internalization rate and cytotoxic effect than AmphPVP-BTZ-DR5-B owing to the presence of fusion protein with internalizing iRGD peptide. Both biocomposites induced cell death via the apoptotic pathway while exhibiting minimal cytotoxic effects on healthy cells. Therefore, biocomposites incorporating BTZ and functionalized with DR5-selective TRAIL variants DR5-B or DR5-B-iRGD represent a promising avenue for future studies in pancreatic cancer animal models.