Thermally Activated Noble Metal Nanoparticles Incorporated in Electrospun Fiber-based Drug Delivery Systems

Background: Nanosystems based on PEG-PLGA copolymer have attracted increasing interest in several biomedicine fields, due to their unique properties. Commonly, PEG-PLGA copolymer was used to formulate nanoparticles (NPs) for drug delivery applications. Only recently, the engineering of polymeric nanofibrous membrane able to be use like drug nanocarrier was investigated. Objective: The goal of this work is the development of two new drug delivery systems based on PEGylated-PLGA nanofibrous scaffolds, obtained by electrospinning deposition, simultaneous loaded with: i) silibinin, a therapeutic agent, ii) Au/Ag and iii) non-toxic Fe2O3 magnetic nanoparticles. Another interest aspect of the present work regards how the morphological structure can influence the drug release which has been fine-tuned by two external stimuli: a light source and a magnetic field. Methods: Noble metal nanocolloids were prepared in water by the pulsed laser ablation technique. The PEG-PLGA@Au/Ag-SLB added with Fe2O3-PVA nanofibers were fabricated by the electrospinning deposition method. Results: The use of “Surface Plasmon Resonance”-mediated localized photothermal effect, determined by the nanoparticles resonant absorption of visible radiation, allows to these systems to be able to employ for photothermal drug delivery therapies in proximity of tumor cells. All data obtained about the fiber scaffolds are compared to NPs based on the same PEG-PLGA copolymer, loaded with silibinin, Fe2O3 and Au/Ag nanoparticles alternatively. Nanofibers respects to NPs, showed interesting sustained responsive silibinin release for at least 60 h, without the burst effect. A diffusion-based theoretical model approach allowed to precisely describe the release mechanism. Conclusion: The effective and controlled silibilin drug release, upon application of either light irradiation or magnetic field for a definite time interval, has been demonstrated. Under the light stimulus, the fiber-shaped nanosystem reached a cumulative drug release value as high as 70% in the long time. On the overall, the information obtained could be useful to design suitable “on demand” nanocomposites in view of a therapeutic treatments protocol that requires a fast pharmacological action.