SiATG5-loaded cancer cell membrane-fused liposomes induced increased uptake of albumin-bound chemotherapeutics by pancreatic cancer cells.

ABSTRACT

Chemotherapeutic efficacy for pancreatic cancer is severely compromised by limited drug availability to tumor cells. Herein, we constructed a cancer cell membrane-fused liposome containing a siATG5-loaded calcium phosphate (CaP) core, termed CLip@siATG5. Through cancer cell membrane camouflage, the liposomes evaded immune clearance, actively infiltrated tumor tissues, and were preferentially taken up by homotypic tumor cells. Then, siATG5 escaped from the endosomes and was liberated in the cytoplasm, mainly benefiting from CaP dissolution-induced endosome rupture and liposome disassembly in acidic endosomes. The released siATG5 silenced autophagy protein 5 (ATG5) to inhibit autophagy, starving tumor cells. An alternative nutrient procurement pathway, macropinocytosis, was then upregulated in the cells, leading to increased uptake of the albumin-bound chemotherapeutic agent (nanoparticle albumin-bound paclitaxel (Nab-PTX)). Finally, in a murine pancreatic cancer model, CLip@siATG5 combined with Nab-PTX exerted superior efficacy to a twofold dose of Nab-PTX while avoiding its toxicity. Overall, we justified enhancing chemotherapeutic delivery by modulating the pancreatic cancer cell metabolism, which will enlighten the development of more effective chemotherapeutic adjuvants for pancreatic cancer in the future.