Human serum albumin-poly(Lactide)-conjugated self-assembly NPs for targeted docetaxel delivery and improved therapeutic efficacy in oral cancer

Abstract

Oral cancer is one of the most prevalent malignancies worldwide. Here, to prepare a biocompatible tumor-targeted nanoformulation capable of efficient loading of the hydrophobic drug, DTX, human serum albumin was conjugated to poly(lactide) at different HSA: PLA ratios (1:1, 2, 3). The HSA-(PLA)_1-3 conjugates were physicochemically characterized by UV, IR, NMR, GPC, pyrene incorporation, and surface tension analysis. Next, the DTX-loaded DTX@HSA-(PLA)_1-3 NPs were prepared by the desolvation-self-assembly technique, which was further optimized by DOE. The NPs were characterized by DLS, SEM, DSC, XRD, CD spectroscopy, SDS-PAGE, drug entrapment and loading efficiencies, kinetic stability, drug release, and hemolysis assays. Murine and human oral cancer cell lines, MOC2 and FaDu, were used in monolayers/multicellular spheroids to assess cellular uptake, the extent of cell viability, and apoptosis induction following NPs treatment. The DTX@HSA-(PLA)_1-3 NPs were ~ 149-212 nm size range, drug entrapment, ~75-96 %, and loading efficiency, ~21-27 %. The selected DTX@HSA-(PLA)₂ NPs showed time-dependent improved targetability towards cancer cells than HSA NPs, indicating the benefit of HSA polymerization in NPs internalization. A time-dependent decrease in cell viability was observed for both the cell lines with IC50 values, 7.12 ± 1.84 and 6.38 ± 1.63 μg/mL, for FaDu and MOC2 cell lines, respectively (48 h post-treatment). The DTX@ HSA-(PLA)₂ NPs treatment induced higher apoptotic marker expressions, cell-cycle arrest in the G2/M-phase, DNA damage, and mitochondrial depolarization than free DTX and DTX@HSA NPs. Further, DTX@HSA-(PLA)₂ NPs (iv) showed significantly reduced plasma clearance (p < 0.05) and volume of distribution (V_d) than DTX and DTX@HSA NPs. Therefore, the developed polyprotein NPs offer superior therapeutic effect due to their stable drug incorporation, improved cell internalization, and long circulation, revealing their potential as an effective nanomedicine for oral cancer treatment.

Keywords: Docetaxel; Human serum albumin; Nanoparticles; Oral cancer; Poly(lactide).