Oligoarginine Peptide Conjugated to BSA Improves Cell Penetration of Gold Nanorods and Nanoprisms for Biomedical Applications

Abstract

Gold nanoparticles (AuNPs) have been shown to be outstanding tools for drug delivery and biomedical applications, mainly owing to their colloidal stability, surface chemistry, and photothermal properties. The biocompatibility and stability of nanoparticles can be improved by capping the nanoparticles with endogenous proteins, such as albumin. Notably, protein coating of nanoparticles can interfere with and decrease their cell penetration. Therefore, in the present study, we functionalized albumin with the r8 peptide (All-D, octaarginine) and used it for coating NIR-plasmonic anisotropic gold nanoparticles. Gold nanoprisms (AuNPrs) and gold nanorods (AuNRs) were coated with bovine serum albumin (BSA) previously functionalized using a cell penetrating peptide (CPP) with the r8 sequence (BSA-r8). The effect of the coated and r8-functionalized AuNPs on HeLa cell viability was assessed by the MTS assay, showing a low effect on cell viability after BSA coating. Moreover, the internalization of the nanostructures into HeLa cells was assessed by confocal microscopy and transmission electron microscopy (TEM). As a result, both nanoconstructs showed an improved internalization level after being capped with BSA-r8, in contrast to the BSA-functionalized control, suggesting the predominant role of CPP functionalization in cell internalization. Thus, our results validate both novel nanoconstructs as potential candidates to be coated by endogenous proteins and functionalized with a CPP to optimize cell internalization. In a further approach, coating AuNPs with CPP-functionalized BSA can broaden the possibilities for biomedical applications by combining their optical properties, biocompatibility, and cell-penetration abilities.

BBB-on-a-chip with integrated micro-TEER for permeability evaluation of multi-functionalized gold nanorods against Alzheimer’s disease

“…The GNR-CTAB was functionalized with polyethylene glycol (PEG), Ang2 and D1 peptides. Briefly, GNR-CTAB was synthetized by a seed-mediated growth method [ 46 , 47 ]. The GNR-CTAB was purified by centrifugation at 16,000 g for 30 min and the pellet was resuspended in Milli-Q water.…”

BBB-on-a-chip with Integrated micro-TEER for permeability evaluation of multi-functionalized gold nanorods against Alzheimer’s disease

“…The GNR-CTAB was functionalized with polyethylene glycol (PEG), Ang2 and D1 peptides. Brie y, GNR-CTAB was synthetized by a seed-mediated growth method [46,47]. The GNR-CTAB was puri ed by centrifugation at 16000 g for 30 min and the pellet was resuspended in Milli-Q water.…”

Impact of Ligand Exchange on Gold Nanostars’ Reshaping, Stabilization, Photothermal Efficiency, and Cell Viability

“…Conversely, a tendency of increasing mitochondrial metabolic activity from 88 to 106% on average when decreasing the concentration from 1 to 0.01 nM was observed for AuNSs covered with each ligand in the NIH3T3 cell line. Mitochondrial metabolic activity slightly above 100% (not statistically significant) could be attributed to a physiological oxidative stress response resulting from exposure to the nanosystems. − In general terms, effects on metabolic activity decrease after AuNS treatment were not significant in the studied conditions and remained above 88% for both cell lines in all concentration ranges studied for AuNSs coated with EPPS, TPPMS, and PEG-COOH. It has been widely studied that nanoparticle’s biocompatibility is intrinsically dependent on their surface’s ligands. − In this case, Good’s buffer, organic phosphine, and the ethylene glycol polymer exhibit appropriate cytocompatibility to the system of coated AuNSs.…”