Abstract
Herein, a library of gold nanorods (GNR) decorated with polyethylene glycol-thiol (PEG-SH) containing different functionalities were synthesized and characterized by optical absorption spectroscopy, zeta potential, dynamic light scattering (DLS), transmission electron microscope (TEM) and proton nuclear magnetic resonance (1H-NMR). The colloidal stability of GNR when exposed to skin, and their preferential accumulation into excised human skin layers were investigated. Confocal laser scanning microscopy, transmission electron microscope (TEM) and inductively coupled plasma-optical emission spectroscopy (ICP-OES) were utilized to track the penetration of GNR into different skin layers. The results demonstrated that cholesterol-PEG coated GNR were preferentially loaded up in the upper layers of skin (stratum corneum), while phospholipid-PEG coated counterparts were drastically deposited in skin dermis. Neutral methoxy-PEG-coated GNR were distributed in both SC and dermis skin layers, while charged GNR (anionic-carboxylic acid-PEG-GNR and cationic-amine-PEG-GNR) revealed a minimal accumulation into skin. DSPE-PEG-GNR and Chol-PEG-GNR demonstrated antibacterial activities against Staphylococcus aureus (S aureus) at MIC values of 0.011 nM and 0.75 nM, respectively. Photothermal treatment for S. aureus at sub-MIC concentrations resulted in a significant bactericidal effect when using Chol-PEG-GNR but not DSPE-PEG-GNR. Gold-based nanoscale systems have great value as a promising platform for skin diseases therapy.
Highlights
Modification of nanoparticles, such as proteins, lipids and oleic acids has increased the permeability and accumulation of nanoparticles into different skin compartments[18,20,21,22,23]
Employing confocal laser scanning microscopy, transmission electron microscopy (TEM) and inductively coupled plasma-optical emission spectroscopy (ICP-OES), the skin penetration and preferential accumulation of gold nanorods (GNR) decorated with phospholipid or cholesterol conjugated to PEG-thiol (SH) were probed and compared to that of GNR decorated with methoxy (m)-PEG or charged PEG moieties
CTAB-assisted synthesis protocol was used to prepare GNR having aspect ratio of ~4 and ~2. This particular shape of GNP was selected owing to their uncommon optical characteristics, superior photothermal and antibacterial activities, and their potential accumulation into skin layers[13,15,18,35,37,38]
Summary
Modification of nanoparticles, such as proteins, lipids and oleic acids has increased the permeability and accumulation of nanoparticles into different skin compartments[18,20,21,22,23]. DSPE-PEG-GNR and Chol-PEG-GNR suspended in water demonstrated relatively low zeta potential values (−10.0 and +9.3, respectively; Fig. 2E). TEM images of DSPE-PEG-GNR, Chol-PEG-GNR and other modified GNR of AR ~ 4 demonstrated well-dispersed rod-shaped nanoparticles having similar particle sizes without significant aggregation (Fig. 3C–F).
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
