In the biomedical field, titanium alloys have long been preferred for orthopedic and dental devices due to their excellent biocompatibility and mechanical strength, making them suitable for long-term implantation. However, recent findings indicate that certain alloying elements, such as vanadium, cobalt, and copper, may pose cytotoxic risks when present at higher concentrations or under specific conditions. As a response to these concerns, current research is focused on developing titanium alloys that feature a lower elastic modulus and improved compatibility with bone elasticity. It also aims to exclude potentially cytotoxic elements and incorporate advanced surface modifications, thereby providing effective solutions to these challenges. Based on these identified needs this review highlights the latest advancements in the design of β-Ti alloys through safer and greener methods. It places particular emphasis on pre-clinical in vitro and in vivo studies that evaluate the safety and performance of implants. Additionally, discusses the potential of artificial intelligence and computational methods for predicting and optimizing alloy properties. Unlike previous reviews that focus mainly on microstructure, mechanical behavior or specific clinical niches, this review includes alloy design and processing with pre-clinical evidence, regulatory and intellectual-property dimensions, and life-cycle and sustainability assessments. By linking β-Ti alloy development to circular-economy strategies, biodegradable metallic alternatives and emerging machine-learning tools for alloy prediction, the review provides a framework for the clinical translation of safer and greener titanium implants, offering a complete overview of the critical factors influencing the future development of titanium alloy implants for biomedical applications.

This work evaluates agarose (AG)- and chitosan (CS)-based hydrogels incorporating a dexamethasone–cyclodextrin complex (Dex) as potential bioink candidates for wound healing applications. For this purpose, biopolymer hydrogels were formulated and tested to determine their structure, morphology, and rheological behavior under different strain, frequency, and temperature conditions, as well as their swelling behavior, surface functionality, protein adhesion capability, and antibacterial activity. Scanning electron microscopy revealed an interconnected membrane-like porous structure in the agarose/chitosan (BAC) hydrogels, which also showed a fibril-like microstructure when Dex was added. X-ray diffraction showed that these structures had a semicrystalline nature, with a main broad peak from approximately 15 to 20°. Rheological tests confirmed the viscoelastic behavior of the developed hydrogels. Chitosan incorporation reduced the rigidity of the formulations, whereas dexamethasone did not significantly affect the viscoelastic response of the BAC hydrogel. Additionally, the temperature sweep showed that Dex did not substantially alter the viscoelastic response of the BAC hydrogel while reducing mass loss after immersion in phosphate-buffered saline and not significantly affecting the swelling behavior. Further, Coomassie blue staining tests demonstrated favorable protein interaction with the BAC-based hydrogels, indicating that Dex incorporation did not compromise their adsorption capacity. Regarding their antibacterial activity, the hydrogels showed no major effects on Escherichia coli and Staphylococcus aureus in disk diffusion tests. However, liquid diffusion tests showed almost no bacterial growth for hydrogels incorporating CS. Thus, the present results demonstrate the potential of the BAC hydrogel system for biomedical and cosmetic applications.

SARS-CoV-2 has become a global pandemic because it is a severe respiratory syndrome that attacks many people worldwide and can lead to death depending on the severity. In recent years, the study of the acquired immune response (T cells) and innate (B cells) has increased to better treat the disease from the quantitative cell count. A picture has begun to emerge revealing that CD4+ T cells, CD8+ T cells, and neutralizing antibodies contribute to the control of SARS-CoV-2 in COVID-19 cases. This work studies the three fundamental components of the adaptive immune system: B cells (the source of antibodies), CD4+T cells, and CD8+T cells and their function against SARS-CoV2. The importance of vaccines and the different types of existing vaccines are discussed. Implications of covid-19 variants on Immunity and vaccine types are also analyzed to understand how the action of the immune system will help treat the disease.