Chitosan-Derived Carbon Dot/Polypyrrole/Hybrid Biomembrane Assembly for Photoresponsive DNA Delivery

DNA condensation, extracellular shielding, and intracellular release impose competing requirements on nonviral polyplexes. Here, chitosan-derived cationic carbonized domains, an in situ polymerized polypyrrole phase, and a protein-bearing hybrid biomembrane shell were spatially organized into a hierarchical plasmid carrier. Carbonization and PPy hybridization retained most fluorescamine-accessible amines while introducing intrinsic fluorescence and NIR responsiveness. Membrane coverage progressively reversed the surface charge and reduced model-protein adsorption, with an intermediate membrane/carrier/DNA ratio providing the optimal balance between interfacial shielding and cellular interaction. The resulting HEV-coated assemblies maintained approximately 84% DNA encapsulation and exhibited pH- and NIR-regulated release. Optimized assemblies achieved 93.38% uptake and 56.66% GFP expression in HeLa cells, while excessive irradiation reduced expression through photothermal cytotoxicity. These findings establish a hierarchical structure−property framework for coupling biopolymer-derived DNA-binding domains, a conjugated polymer phase, and a biological macromolecular interface.