Tannic Acid Coated Gold Nanorods Demonstrate a Distinctive Form of Endosomal Uptake and Unique Distribution within Cells

Abstract

One of the primary challenges associated with nanoparticle-dependent biological applications is that endosomal entrapment in a physiological environment severely limits the desired targeting and functionality of the nanoconstructs. This study sought to overcome that challenge through a systematic approach of gold nanorod (GNR) functionalization: evaluating the influence of both aspect ratio and surface chemistry on targeted cellular internalization rates and preservation of particle integrity. Owing to their unique spectral properties and enhanced surface area, GNRs possess great potential for the advancement of nanobased delivery and imaging applications. However, their ability for efficient intracellular delivery while maintaining their specific physiochemical parameters has yet to be satisfactorily explored. This study identified that longer and positively charged GNRs demonstrated a higher degree of internalization compared to their shorter and negative counterparts. Notably, of the four surface chemistries explored, only tannic acid resulted in retention of GNR integrity following endocytosis into keratinocyte cells, due to the presence of a strong protein corona matrix that served to protect the particles. Taken together, these results identify tannic acid functionalized GNRs as a potential candidate for future development in nanobased biomolecule delivery, bioimaging, and therapeutic applications.

Reviewing the Tannic Acid Mediated Synthesis of Metal Nanoparticles

“…Moreover, they successfully demonstrate that such gold nanoplates can be used as building blocks for creating biosensor capable of detecting glucose in buffer as well as human serum. Moreover, Untener et al [70] have demonstrated a distinctive uptake of tannic acid coated gold nanorods by endosomes and their unique distribution within the cell. Their study reveals that tannic acid functionalized gold nanorods maintain their integrity after being endocytosed by the keratinocyte endosomes which indicates their potential candidature as nanodelivery agents, nanobioimaging tools, and nanotherapeutics.…”

Preliminary protein corona formation stabilizes gold nanoparticles and improves deposition efficiency

“…While biomedical applications vary in function, what they have in common is the need for a high AuNP delivery rate to be effective. Current design efforts to improve colloid delivery and deposition have focused on material-based approaches, specifically through modification of particle size or surface chemistry (Bannunah et al 2014;Untener et al 2013). While these efforts have been met with moderate success, much work remains to optimize NP deposition and dosimetry (Pal et al 2015).…”

Slow release of ions from internalized silver nanoparticles modifies the epidermal growth factor signaling response

“…Of particular interest was how the kinetic rate of ionic dissolution, as a function of both environment and time, influenced activation of stress and signaling pathways. For this study, a human keratinocyte, HaCaT, cell model was selected due to the considerations that skin is a primary exposure route for most nano-silver applications and HaCaTs have become a model cell line for NP behavior [24][25][26]. Our analyses revealed that AgNPs induced a two-phase disruption of EGF signal transduction, which were directly related to the rates of stress activation and ionic dissolution.…”