Nano-Hybrid Au@LCCs Systems Displaying Anti-Inflammatory Activity

Abstract

Gold nanoparticles (Au NPs) have received great attention owing to their biocompatible nature, environmental, and widespread biomedical applications. Au NPs are known as capable to regulate inflammatory responses in several tissues and organs; interestingly, lower toxicity in conjunction with anti-inflammatory effects was reported to occur with Au NPs treatment. Several variables drive this benefit-risk balance, including Au NPs physicochemical properties such as their morphology, surface chemistry, and charge. In our research we prepared hybrid Au@LCC nanocolloids by the Pulsed Laser Ablation, which emerged as a suitable chemically clean technique to produce ligand-free or functionalized nanomaterials, with tight control on their properties (product purity, crystal structure selectivity, particle size distribution). Here, for the first time to our knowledge, we have investigated the bioproperties of Au@LCCs. When tested in vitro on intestinal epithelial cells exposed to TNF-α, Au@LCCs sample at the ratio of 2.6:1 showed a significantly reduced TNF gene expression and induced antioxidant heme oxygenase-1 gene expression better than the 1:1 dispersion. Although deeper investigations are needed, these findings indicate that the functionalization with LCCs allows a better interaction of Au NPs with targets involved in the cell redox status and inflammatory signaling.

Nano-Hybrid Ag@LCCs Systems with Potential Wound-Healing Properties

“…STEM images of the Ag@LCCs samples at different ratios are shown in Figure 5 . Although weak, the intermolecular van der Waals interactions allowed the creation of bundles constituted by sp and sp hybridized carbons [ 50 ] interconnecting Ag NPs (see Figure 5 a–d) in a similar way to that already observed for Au@LCC nanocolloids [ 36 ]. Both Ag@LCCs samples consisted of a mixture of Ag NPs conjugated with LCCs and individual Ag NPs.…”

“…The biocompatibility of Ag NPs, LCCs, and the two different Ag@LCCs dispersions (Ag@LCCs 1:3, Ag@LCCs 3:1) on NIH/3T3 fibroblasts was investigated using the sulforhodamine B (SRB) assay, as previously described [ 36 , 40 , 41 ]. Briefly, NIH/3T3 cells (3.5 × 10 cells/well) were plated in 96-well cell plates, and after 24 h, semi-confluent (around 60%) monolayers were treated for 24 h with: Ag NPs, range 3.2–20 µg/mL; LCCs, range: 4.3–60 µg/mL; the two different Ag@LCCs dispersions (ratios 1:3 and 3:1), range 3.2–20 µg/mL expressed as Ag.…”

“…The NIH/3T3 cells were grown in 6-well plates up to around 90–95% confluence, using the culture conditions described in [ 36 ]. At the center of the cell monolayer, a scratch was created using a sterile 200 µL plastic tip to simulate a wound, and then, the cellular debris was washed out with PBS.…”

“…However, even though exceptional properties have been theoretically predicted for LCCs [ 30 , 31 , 32 ], their highly reactive sp electronic configuration causes critical stability issues [ 33 ], limiting their real use, as also recently confirmed by Kim et al, who used Au NPs to improve the system stability [ 34 ]. Among the approaches developed to prevent linear chains’ fast degradation, the pulsed laser ablation (PLAL) technique has gained great favor [ 10 ], since it allows the synthesis of both metal and LCC colloids in a single, clean, and green approach [ 35 , 36 ]. Other recent approaches consider the formation of Au-pseudocarbynes by taking advantage of self-assembly processes involving earlier prepared gold clusters and polyynes in solution [ 37 ].…”