Surface Plasmon Resonance- based biosensors for medical and pharmaceutical applications

C. Y. CHAIN

Otro; Humboldt Colloquium ?Shaping the Future of German-Argentinian Scientific Cooperation ? The Role of Curiosity-Driven Research?; 2018

Surface Plasmon Resonance (SPR) -based biosensors allow to efficiently measuring the binding events to a surface through the changes in the refractive index produced by those events. Our research is focused in the development of SPR- based biosensors with medical and pharmaceutical applications. Concerning medical applications, it is of our interest the development of biosensors to diagnose, to make prognosis and to follow the treatment of infectious, metabolic and tumour diseases, among others. In particular, we are working in the design and applicability of SPR- based immunosensors for the diagnosis of neglected tropical diseases, i.e. Chagas disease and cutaneous Leishmaniasis. With this purpose, sensor platforms based in specific antigens of the etiological agent are constructed and used to develop SPR- based immunoassays intended to detect specific antibodies in sera. The antigens are immobilized on SPR sensor surfaces via activated- short and long carboxylated thiol monolayers by amide coupling. The capacity of the sensor surfaces to detect the specific antibodies is evaluated using sera with and without the analyte of interest. Operational parameters of the immunoassay as time of immobilization and antigen concentration, conditions that minimize the non- specific signal (serum dilution, blocking of the surface) and surface regeneration are optimized. Respect to the pharmaceutical applications, our objective is to apply the SPR technique to study the interactions among nanoparticles of different chemical nature (metal, lipid, polymeric) and plasma proteins, allowing deepening in the ?biological identity? of the nanoparticles in the bloodstream. The aim of these studies is to correlate the features of the protein corona with the circulation times of nanoparticles, thus allowing optimizing the synthesis of the particles in order to maximize the efficiency of the therapy. In this sense, we have reported the synthesis and characterization of solid lipid nanoparticles (SLN) coated with polymers of different chemical nature (e.g., polyvinyl alcohol, chitosans). The proof-of-concept for the use of SPR technique in characterizing protein-nanoparticle interactions of surface-immobilized proteins (immunoglobulin G ?IgG- and bovine serum albumin ?BSA-, both involved in the formation of the corona) subjected to flowing SLN was demonstrated for non-chitosan-coated nanoparticles. All assayed nanosystems show more preference for IgG than for BSA, such preference being more pronounced in the case of polyvinyl-alcohol-coated SLN.