The major goal in designing nanosystems as drug delivery vectors is to control the release of pharmacologically active agents and to achieve the site-specific action of drugs at a therapeutically optimal rate and dosage regimen. Targeting of the nanocarrier at the action site and shielding of the surface to reduce adsorption of non-specific proteins are crucial aspects for augmenting the therapeutic efficacy. In this respect, studies about interactions between drugs and serum protein are of particular interest. The strategy of “drug delivery vectors” which is widely applied to the medical field can be translated to phyto-therapy with the aim of developing sustainable antimicrobial protection of plants. Beyond nanosystems, surfaces can be functionalized to release antimicrobial agents on demand.
Inorganic nano-carriers for targeted therapy
Among inorganic nanostructures, our research efforts have focused on the design of several types of multifunctional nanoparticles (NPs), such as magnetic or metallic nanoparticles and halloysite nanotubes loaded with anticancer drugs or used directly as therapeutic tools. Superparamagnetic NPs can be guided with a magnetic field to deliver attached drugs, in addition to hyperthermia treatment. In silver and silver-coated silica NPs, the metallic domain induces cell death upon laser irradiation and reactive oxygen species generation.
Plasmonic NPs are a class of metallic nanomaterials that mediate Localized Plasmon Resonance (LPR), resulting in highly enhanced electromagnetic fields (eg light) in their immediate neighbourhood. This can be exploited for triggering localised drug release or directly to kill diseased tissues via heat release, while sparing adjacent healthy tissues (Plasmonic PhotoThermal Therapy, PPTT). The possibility to deliver NPs to a tumor site and then exploit the efficient conversion of Near Infrared (NIR) light to heat opens up a new “drug-free” cancer therapy.
Another class of novel inorganic biocompatible nanomaterials for biomolecular delivery are Halloysite clay Nanotubes which are composed of double layered aluminosilicate minerals with a hollow tubular structure in the submicron range and are capable of entrapping and releasing drugs within the inner lumen.
NPs can deliver a variety of biomolecules; of particular relevance is the gene delivery process that allows the introduction of foreign DNA or RNA into host cells for therapy avoiding immune response in the patient. In this frame, we have combined NPs and a human whole genomic DNA exploiting the possibility to realize applications for Plasmonic Gene Therapy (PGT). The interaction between NPs and nucleic acids of different lengths have been studied by using analytical techniques such as Scanning Electron-Microscopy (SEM), Electrophoretic mobility assay and Zeta-potential measurements.