Chitosan, Gelatin, and Collagen Hydrogels for Bone Regeneration.

Hydrogels are versatile biomaterials characterized by three-dimensional, cross-linked, highly hydrated polymeric networks. These polymers exhibit a great variety of biochemical and biophysical properties, which allow for the diffusion of diverse molecules, such as drugs, active ingredients, growth factors, and nanoparticles. Meanwhile, these polymers can control chemical and molecular interactions at the cellular level. The polymeric network can be molded into different structures, imitating the structural characteristics of surrounding tissues and bone defects. Interestingly, the application of hydrogels in bone tissue engineering (BTE) has been gathering significant attention due to the beneficial bone improvement results that have been achieved. Moreover, essential clinical and osteoblastic fate-controlling advances have been achieved with the use of synthetic polymers in the production of hydrogels. However, current trends look towards fabricating hydrogels from biological precursors, such as biopolymers, due to the high biocompatibility, degradability, and mechanical control that can be regulated. Therefore, this review analyzes the concept of hydrogels and the characteristics of chitosan, collagen, and gelatin as excellent candidates for fabricating BTE scaffolds. The changes and opportunities brought on by these biopolymers in bone regeneration are discussed, considering the integration, synergy, and biocompatibility features.

Atherosclerotic-Derived Endothelial Cell Response Conducted by Titanium Oxide Nanotubes.

Atherosclerosis lesions are described as the formation of an occlusive wall-vessel plaque that can exacerbate infarctions, strokes, and even death. Furthermore, atherosclerosis damages the endothelium integrity, avoiding proper regeneration after stent implantation. Therefore, we investigate the beneficial effects of TiO2 nanotubes (NTs) in promoting the initial response of detrimental human atherosclerotic-derived endothelial cells (AThEC). We synthesized and characterized NTs on Ti6Al4V by anodization. We isolated AThEC and tested the adhesion long-lasting proliferation activity, and the modulation of focal adhesions conducted on the materials. Moreover, ultrastructural cell-surface contact at the nanoscale and membrane roughness were evaluated to explain the results. Our findings depicted improved filopodia and focal adhesions stimulated by the NTs. Similarly, the NTs harbored long-lasting proliferative metabolism after 5 days, explained by overcoming cell-contact interactions at the nanoscale. Furthermore, the senescent activity detected in the AThEC could be mitigated by the modified membrane roughness and cellular stretch orchestrated by the NTs. Importantly, the NTs stimulate the initial endothelial anchorage and metabolic recovery required to regenerate the endothelial monolayer. Despite the dysfunctional status of the AThEC, our study brings new evidence for the potential application of nano-configured biomaterials for innovation in stent technologies.

Azadirachta indica Leaf Extract as Green Corrosion Inhibitor for Reinforced Concrete Structures: Corrosion Effectiveness against Commercial Corrosion Inhibitors and Concrete Integrity.

The construction industry has extensively demanded novel green inhibition strategies for the conservation and protection of carbon steel-reinforced concrete structures. For the first time, the effect of Azadirachta indica leaf extract (Neem) as a potential corrosion inhibitor of carbon steel in reinforced concrete under corrosion in saline simulated media was evaluated. To assess the corrosion inhibition behavior of the Neem natural organic extract, three inorganic commercial inhibitors were tested to compare following the criteria established by Stratful for half-cell potential under a simulated chloride environment. Moreover, the effect of concrete integrity by the Neem treatment was recorded after different temperature conditions, slump, weight alteration, air content, compressive strength, and chloride-ions penetration. The results suggested that the Neem treatments did not alter the concrete integrity and the physicochemical parameters. We reached a promoted long-term corrosion protection of 95% after 182 days of evaluation. Thus far, our current results open up a new promising "green" road to the conservation of carbon steel in reinforced concrete for the construction industry.

Promotion of Surgical Masks Antimicrobial Activity by Disinfection and Impregnation with Disinfectant Silver Nanoparticles.

BACKGROUND: The COVID-19 pandemic is requesting highly effective protective personnel equipment, mainly for healthcare professionals. However, the current demand has exceeded the supply chain and, consequently, shortage of essential medical materials, such as surgical masks. Due to these alarming limitations, it is crucial to develop effective means of disinfection, reusing, and thereby applying antimicrobial shielding protection to the clinical supplies. PURPOSE: Therefore, in this work, we developed a novel, economical, and straightforward approach to promote antimicrobial activity to surgical masks by impregnating silver nanoparticles (AgNPs). METHODS: Our strategy consisted of fabricating a new alcohol disinfectant formulation combining special surfactants and AgNPs, which is demonstrated to be extensively effective against a broad number of microbial surrogates of SARS-CoV-2. RESULTS: The present nano-formula reported a superior microbial reduction of 99.999% against a wide number of microorganisms. Furthermore, the enveloped H5N1 virus was wholly inactivated after 15 min of disinfection. Far more attractive, the current method for reusing surgical masks did not show outcomes of detrimental amendments, suggesting that the protocol does not alter the filtration effectiveness. CONCLUSION: The nano-disinfectant provides a valuable strategy for effective decontamination, reuse, and even antimicrobial promotion to surgical masks for frontline clinical personnel.