Impact of the functional coating of silver nanoparticles on their in vivo performance and biosafety

Silver nanoparticles (AgNPs) have become an interesting therapeutic modality and drug delivery platform. Herein, we aimed to investigate the impact of functional coating on the in vivo performance of AgNPs as an economic and scalable method to modulate their behavior.

AgNPs were coated with chitosan (CHI) as a model biopolymer using a one-pot reduction-based method, where CHI of two molecular weight ranges were investigated. The resultant CHI-coated AgNPs (AgNPs-CHI) were characterized using UV-VIS spectroscopy, DLS, and TEM. AgNPs were administered intravenously to rats and their biodistribution and serum levels of hepato-renal function markers were monitored 24 h later compared to plain AgNO₃ as a positive control.

UV-VIS spectroscopy confirmed the successful coating of AgNPs with CHI. DLS revealed the superiority of medium molecular weight CHI over its low molecular weight counterpart. AgNPs-CHI demonstrated a semi-complete clearance from the systemic circulation, a liver-dominated tissue tropism, and limited renal exposure. On the other hand, AgNO₃ was poorly cleared from the circulation, with relatively high renal exposure and a non-specific tissue tropism. AgNPs-CHI were well-tolerated by the liver and kidney without signs of toxicity or inflammation, in contrary with AgNO₃ which resulted in a significant elevation of Creatinine (CRE), Urea, and Total Protein (TP), suggesting a significant nephrotoxicity and inflammation.

Functional coating of AgNPs with CHI substantially modulated their in vivo behavior, promoting their hepatic selectivity and biotolerability, which can be invested in the development of drug delivery systems for the treatment of liver diseases.