Engineering biopolymer-coated gold nanoparticles for drug delivery application.

In recent years, nanomedicine, an interdisciplinary field that combines nanotechnology and medicine, has revolutionized the field of medicine thanks to its innovative solutions for drug delivery, diagnostic analysis, medical treatment, and theranostics. Due to their specific properties derived from the nanoscale, nanoparticles are considered a promising agent to revolutionize healthcare. However, synthesizing nanoparticles with the right size and desired characteristics is still a great challenge. After a brief introduction to nanomedicine and nanoparticles as nanocarriers, this Master's Thesis provides an analysis of the synthesis and characterization of polymer-coated Gold Nanoparticles (AuNPs) to advance drug delivery applications in the field of cancer treatment. The first part of this study explores the synthesis of polymer-coated AuNPs using different chemical protocols. The polymeric coatings were obtained with chemically modified glycosaminoglycans. The first polymeric coating was obtained with non-sulfated Hyaluronic Acid while sulfated Heparin was used for the second coating. This experimental work includes the choice of the appropriate protocol and reaction conditions to obtain AuNPs with the desired physiochemical properties. This choice was made by paying special attention to AuNPs size and degree of surface functionalization. The second part of this Thesis mainly focuses on the inclusive physiochemical characterization of the synthesized AuNPs. This detailed characterization aims to assess if the synthesized nanoparticles met the requirements for drug delivery applications. Different techniques were utilized to evaluate their size, surface charge, and degree of surface functionalization. Dynamic Light Scattering (DLS) was utilized to determine the hydrodynamic size distribution of the nanoparticles. Ultraviolet-visible (UV-Vis) and Nuclear Magnetic Resonance (NMR) spectroscopy measurements were utilized to assess the degree of chemical functionalization. In addition, Zeta potential measurements were conducted to measure the surface charge of the obtained nanoparticles. The third part of this work examines the potential ability of the AuNPs to interact with living cells. The AuNPs were loaded with a fluorescent molecule and incubated with living cells. This in vitro study made it possible to evaluate the cellular uptake of the fluorescent-marked AuNPs. Finally, future developments of this project work are highlighted. In conclusion, this Master’s Thesis presents a wide exploration of gold nanoparticle synthesis and characterization. The results highlight the optimal protocols to obtain AuNPs that meet the physiochemical properties required for effective drug delivery.