Multi-mechanistic mitochondria-mediated N-methylated YKWYYRGAA-decorated nano-chitosan conjugate carrier for treatment of NRAS-mutant-harbouring lung carcinoma.

Cell targeting/permeabilization, organelle/biochemical pathway regulation, and drug resistance/metastasis/immunological expressions are considerations to advance cancer nanomedicine design. This study modulated mitochondria-targeting YKWYYRGAA (P1) peptide, into a multifunctional excipient via N-methylation and N-dimethylation, to synergise nano-chitosan conjugate in drug delivery and non-small cell lung cancer treatment. The spray-dried chitosan nanoparticles developed from P1, N-methylated YKWYYRGAA (P2) and N-dimethylated YKWYYRGAA (P3) were subjected to physicochemical testing, NRAS-mutated H1299 cell permeability/cytotoxicity/apoptosis and cell cycle arrest/drug resistance/metastasis/immunomodulation assessment, and in vivo pharmacokinetics/pharmacodynamics investigations. Methylated P2 increased cancer cell permeability/intracellular drug/nanoparticle uptake/drug targeting via sustained- and pH-stimuli responsive release and cytotoxicity unlike P1 and P3 which were ceased at membrane interface by excessive ionic/hydrophobic interactions. P2-grafted nanochitosan induced mitochondria-mediated apoptosis with minimal necrosis via ROS activation and FasL-linked death. It suppressed mTOR/MAPK signalling overcoming EGFR-resistance/EGFR mutation-independent pathways in tumorigenesis. It mitigated drug resistance via downregulating P-gp (efflux receptor) and GSTP1 (degrading enzyme) expressions, and epithelial-mesenchymal transition via interplay of E-cadherin against N-cadherin/snail/twist 1/vimentin/ezrin/MMP9 with MICA/ULBP1 suppression to reduce immunological lung tissue lysis. The inhaled P2-grafted nanochitosan provided a positive lung cancer recovery with reduced systemic exposure and hematological/biochemical toxicities. Single instead of dimethylation of YKWYYRGAA promoted the cascades of inter-dependent anti-cancer activities and efficacy of nanochitosan.