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.

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.

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.

Graphitic carbon nitride (g-C₃N₄) is emerging as one of the most promising non-metallic semiconductors for the degradation of pollutants in water by photocatalytic processes. Its exceptional reduction–oxidation (redox) potentials and adequate band gap of approximately 2.7 eV give it the ability to absorb in the visible light range. However, the characteristic sensitivity to light absorption is limited, leading to rapid recombination of electron–hole pairs. Therefore, different strategies have been explored to optimize this charge separation, among which the formation of heterostructures based on g-C₃N₄ is highlighted. This review addresses recent advances in photocatalysis mediated by g-C₃N₄ heterostructures, considering the synthesis methods enabling the optimization of the morphology and active interface of these materials. Next, the mechanisms of charge transfer are discussed in detail, with special emphasis on type II, type S, and type Z classifications and their influence on the efficiency of photodegradation. Subsequently, the progress in the application of these photocatalysts for the degradation of water pollutants, such as toxic organic dyes, pharmaceutical pollutants, pesticides, and per- and polyfluoroalkyl substances (PFAS), are analyzed, highlighting both experimental advances and remaining challenges. Finally, future perspectives oriented towards the optimization of heterostructures, the efficiency of synthesis methods, and the practical application of these in photocatalytic processes for environmental remediation.

Cerium oxide nanoparticles (CeO₂-NPs) offer promising advantages in semiconductors and biomedical applications due to their optical, electrical, antioxidant, and antibacterial properties. However, the widely reported synthetic strategies for CeO₂-NPs demand toxic precursors and intermediary pollutants, representing a major limitation to CeO₂-NPs applications. Therefore, it is necessary to develop greener strategies that implicate ecological precursors to reduce the negative impact on the scalability of CeO₂-NPs. In this regard, we applied Lycium cooperi (L. cooperi) aqueous extracts as an unexplored potential green reducing agent for the eco-friendly synthesis of CeO₂-NPs. The L. cooperi extract showed the presence of alkaloids, flavonoids, cardiac glycosides, and carbohydrate-derived families, which were assessed for spherical monodispersed CeO₂-NPs under a rapid chemical reduction. Moreover, the elemental composition revealed Ce and O, indicating highly pure CeO₂-NPs characterized by an interplanar cubic crystalline structure. Furthermore, we detected the presence of stabilizing functional groups from L. cooperi, which, after a controlled annealing process, resulted in a band gap energy of 3.9 eV, which was optimal for the CeO₂-NPs. Thus, the results indicate that L. cooperi is an environmentally friendly synthesis method that can open a new route for CeO₂-NPs in biomedical and industrial applications.