Influence of Silver Nanoparticles on Liposomal Membrane Properties with Relevance to Drug Delivery and Photothermal Therapy

Silver nanoparticles (AgNPs) are promising agents for nanomedicine but their interactions with lipid membranes, which are a key interface for drug delivery, require deeper understanding. This study investigates the influence of fructose-capped AgNPs on the physicochemical properties of SOPC-based liposomal bilayers, with implications for drug delivery and photothermal therapy. We employed a multi-technique approach, including infrared (IR) spectroscopy, differential scanning calorimetry (DSC), thermally induced shape fluctuation analysis, and laser irradiation at 343, 515, and 1030nm. Our results show that AgNPs incorporated into the bilayer are causing measurable perturbations: DSC revealed a decrease in the main phase transition enthalpy (from 0.280 to 0.234 J/g) and temperature (from 2.80 to 3.41 °C) while shape fluctuation analysis indicated a reduction in bending modulus (from 1.18 × 10−19 J to 0.93 × 10−19 J), confirming increased membrane fluidity. FTIR confirmed interactions of fructose-capped nanoparticles and lipid’s carbonyl and phosphate groups. Furthermore, the AgNPs-liposomes exhibited a strong, wavelength- dependent photothermal response with a temperature increase ≈22 °C under 515 nm laser irradiation, compared to only 3–5 °C at 1030nm. We concluded that fructose-capped-AgNPs moderately fludify lipid bilayers while enabling efficient, controllable photothermal capability, making them excellent candidates for designing advanced liposomal systems for combined therapy and diagnostic.