Rationally designed, synthesized, and characterization of anti-PD-L1 peptide conjugated temozolomide self-assembled prodrug nanoparticles for targeted lung cancer chemoimmunotherapy.

Lung cancer remains foremost cause of cancer-related deaths worldwide. Over the past decade, conventional monotherapies frequently limited by therapeutic resistance and dose-limiting toxicity. To address these limitations, the present study aimed to design and evaluate anti-PD-L1 peptide-conjugated temozolomide self-assembled prodrug nanoparticles (PD-NPs) in lung cancer chemoimmunotherapy. PD-NPs were synthesized and extensively characterized by different analytical techniques. Molecular docking and molecular dynamic simulation studies further validated the protein-ligand interactions and demonstrated the structural stability of PD-NPs in physiological conditions. In vitro studies, including cellular viability, clonogenicity, cellular uptake, scratch assay, apoptosis, flow cytometry, and western blotting were performed in A549 and NCI-H460 cell lines. Subsequently in vivo toxicity studies were performed and established a safe and tolerable therapeutic range for further investigation. Chemoimmunotherapeutic evaluation were conducted in B16-F10-induced lung tumor bearing C57BL/6 allograft mice model. Biodistribution study, histopathology, immunohistochemistry, qRT-PCR, ELISA, microarray analysis, cell proliferation study, and apoptosis assay were performed to elucidate therapeutic efficacy of PD-NPs. PD-NPs exhibited favorable physicochemical profile with a zeta potential of +32.2 mV, and uniform nanoscale size (DLS: 208.1 ± 3.7 nm and TEM: 206.2 ± 3.5 nm), facilitating effective tumor microenvironment penetration. In vitro studies demonstrated that PD-NPs significantly reduced cancer cell viability. In vivo studies revealed significant tumor regression, restoration of typical lung tissue architecture, downregulation of oncogenic and immunosuppressive markers (KRAS, MEK, FOXM1, and PD-L1), and enhanced CD8 T-cell activation. Overall, PD-NPs demonstrated potent chemoimmunotherapeutic efficacy by modulating both carcinogenic and immune-regulatory pathways, highlighting their potential as a next-generation therapeutic platform for lung cancer chemoimmunotherapy.