Functionalized PLGA-Based Nanoparticles with Anti-HSV-2 Human Monoclonal Antibody: A Proof of Concept for Early Diagnosis and Targeted Therapy

Background: Functionalized nanoparticles (NPs) represent a cutting edge in innovative clinical approaches, allowing for the delivery of selected compounds with higher specificity in a wider time frame. They also hold promise for novel theranostic applications that integrate both diagnostic and therapeutic functions. Pathogens are continuously evolving to try to escape the strategies designed to treat them. Objectives: In this work, we describe the development of a biotechnological device, Nano-Immuno-Probes (NIPs), for early detection and infections treatment. Human Herpes Simplex Virus 2 was chosen as model pathogen. Methods: NIPs consist of PLGA-PEG-Sulfone polymeric NPs conjugated to recombinant Fab antibody fragments targeting the viral glycoprotein G2. NIPs synthesis involved multiple steps and was validated through several techniques. Results: DLS analysis indicated an expected size increase with a good polydispersity index. Z-average and z-potential values were measured for PLGA-PEG-Bis-Sulfone NPs (86.6 +/- 10.9 nm; -0.7 +/- 0.3 mV) and NIPs (151 +/- 10.4 nm; -5.1 +/- 1.9 mV). SPR assays confirmed NIPs' specificity for the glycoprotein G2, with an apparent KD of 1.03 +/- 0.61 mu M. NIPs exhibited no cytotoxic effects on VERO cells at 24 and 48 h. Conclusions: This in vitro study showed that NIPs effectively target HSV-2, suggesting the potential use of these nanodevices to deliver both contrast agents as well as therapeutic compounds.