Fabrication of a ternary β-glucan/homopolynucleotide/polyethyleneimine complex for enhanced cellular uptake in gene...

Polyethylenimine (PEI)-functionalized lentinan/poly(deoxyadenylic acid) (s-LNT/poly(dA)) nanocomposites were developed to overcome the cellular uptake limitations of s-LNT/poly(dA) composite-based carriers. The ternary s-LNT/poly(dA)/PEI complexes were prepared through electrostatic and hydrogen-bonding interactions, systematically characterized using fourier-transform infrared spectroscopy (FT-IR), zeta potential analysis, transmission electron microscopy (TEM), circular dichroism (CD), ultraviolet-visible (UV-Vis) spectroscopy, and fluorescence spectroscopy. The results demonstrate that PEI interacted with s-LNT/poly(dA) via hydrogen bonding and electrostatic interactions, leading to a morphological transition from chain-like to compact spherical nanoparticles and a charge reversal from -18 mV to near-neutrality. Crucially, cellular uptake studies using flow cytometry and confocal laser scanning microscopy (CLSM) reveal that PEI significantly enhanced the internalization of the s-LNT/poly(dA) complex by MCF-7 cells, with uptake efficiency increasing from 5.14% to 94.5%. And the formation of the s-LNT/poly(dA)-FAM complex was an essential prerequisite for PEI-mediated enhancement of cellular uptake. Cytotoxicity assays confirmed the biocompatibility of the complex, with cell viability maintaining above 65% even at higher PEI concentrations. This work provides an effective strategy to establish PEI-functionalized β-glucan/nucleic acid composites as promising platforms for advanced gene delivery applications.