Folate-containing β-lactoglobulin/pectin nanocarriers for oxalipalladium delivery: physicochemical and in vitro evaluation in HCT116 cells.

This study characterized β-lactoglobulin/low-methoxyl-pectin formulations containing oxalipalladium, compared preparations with and without folic acid, and evaluated pH-buffer release and HCT116 cell responses. Formulations were assessed by dynamic light scattering, zeta-potential measurement, spectrophotometric encapsulation-efficiency estimation, scanning electron microscopy, and atomic-force microscopy. Dialysis-based release was assessed in buffers at pH 1.2, 4.5, 7.0, and 7.5. HCT116 responses were examined by MTT, Annexin V/propidium iodide flow cytometry, and RT-qPCR. At pH 4.5, particle sizes were 40 nm with folic acid and 164 nm without folic acid; corresponding zeta potentials were - 10.53 and - 8.88 mV, PDI values were 0.10 and 0.14, and operational encapsulation-efficiency estimates were 75.2% and 69.6%. Release was lower in acidic buffers and greater at pH 7.0-7.5. MTT analysis demonstrated concentration-dependent reductions in HCT116 viability. Annexin V-positive fractions were 40.2% for the folate-containing formulation, 11.85% for the folate-free formulation, and 4.5% for untreated cells. RT-qPCR showed directional changes in selected apoptosis-associated and topoisomerase transcripts. These findings support enhanced in vitro potency of the folate-containing formulation under the tested conditions, while receptor-mediated targeting, selective toxicity, and in vivo efficacy require separate validation.