RESUMO
To endow an implant surface with enhanced properties to ensure an appropriate seal with the host tissue for inflammation/infection resistance, next-generation bone implant collagen-polyphenol nanolayers were built on conventional titanium surfaces through a multilayer approach. X-ray Photoelectron Spectroscopy (XPS) analysis was performed to investigate the chemical arrangement of molecules within the surface layer and to provide an estimate of their thickness. A short-term (2 and 4 weeks) in vivo test of bone implants in a healthy rabbit model was performed to check possible side effects of the soft surface layer on early phases of osteointegration, leading to secondary stability. Results show the building up of the different nanolayers on top of titanium, resulting in a final composite collagen-polyphenol surface and a layer thickness of about 10 nm. In vivo tests performed on machined and state-of-the-art microrough titanium implants do not show significant differences between coated and uncoated samples, as the surface microroughness remains the main driver of bone-to-implant contact. These results confirm that the surface nanolayer does not interfere with the onset and progression of implant osteointegration and prompt the green light for specific investigations of the potential merits of this bioactive coating as an enhancer of the device/tissue seal.
RESUMO
Novel Psychoactive Substances (NPS) include several classes of substances such as synthetic cannabinoids (SCBs), an emerging alternative to marijuana, easily purchasable on internet. SCBs are more dangerous than Δ9-Tetrahydrocannabinol as a consequence of their stronger affinities for the CB1 and CB2 receptors, which may result in longer duration of distinct effects, greater potency, and toxicity. The information on SCBs cytotoxicity, genotoxicity, mutagenicity, and long-term effects is scarce. This fact suggests the urgent need to increase available data and to investigate if some SCBs have an impact on the stability of genetic material. Therefore, the aim of the present study was the evaluation of the mutagenic effect of different SCBs belonging to indole- and indazole-structures. The analyzes were conducted in vitro on human TK6 cells and mutagenicity were measured as micronucleus fold increase by flow cytometry. Our results have highlighted, for the first time, the mutagenic capacity of four SCBs, in particular in terms of chromosomal damage induction. We underline the serious potential toxicity of SCBs that suggests the need to proceed with the studies of other different synthetic compounds. Moreover, we identified a method that allows a rapid but effective screening of NPS placed on the market increasingly faster.
