Analyzing release kinetics modelling, cytotoxicity and stability testing of gabapentin linked thiol and cysteine functionalized monodispersed gold nanoparticles

Nanomedicine has emerged as an area of research that has earned a lot of attention in the past decade along with frequent and sustained advancements leading to its extensive plethora of biomedical applications. Following the same, the drug carrier systems like gold nanoparticles (AuNPs) have become the success stories with many marketed formulations now and has proved to be a most suitable answer to the drug delivery concers due to their exclusive electrical and optical properties. They serve as one of the best surfaces to either adsorb, attach, or conjugate and exhibit remarkable optoelectronic, physicochemical, morphological and functional properties. In this study, Gabapentin (GBP) a known FDA approved anti-epileptic drug is selected for improving its pharmaceutical limitations and we have synthesized monodispersed AuNPs for GBP conjugation using citrate reduction method. Here the research group has modified AuNP surfaces with three different thiol moieties namely, Mercaptopropionic acid (3-MPA), 11-Mercaptoundecanoic acid (11-MUA) and the amino acid L-Cysteine (L-Cys) and then attached the GBP with these linkers. The synthesized GBP–AuNP nano-conjugate moieties were further characterized and tested for their in-vitro cytotoxicity, release kinetics and stability properties. The in-vitro release kinetics and cytotoxicity (MTT-Assay) analysis of the formulated GBP–AuNP nano-conjugates along with all the 3 types of linkers was carried out and after the data analysis for the same, it was observed that the GBP–AuNP nano-conjugate with L-Cys linker exhibited the sustained release pattern and non- significant cytotoxicity followed by MUA and MPA, respectively. Moreover, the assessment of GBP-AuNPs evaluated through the comprehensive release kinetics analysis, reinforced the GBP-thiol linkers as potentially more effective and competent than GBP alone. Furthermore, all the experimental data was validated by statistical method, and it can be concluded from the present study that the symmetrical monodispersed AuNPs formulation coated with stable functionalized thiol layer were synthesized with minimal cytotoxicity and can be further explored as an efficient drug delivery system for therapeutic application.