Synergistic effect of Cydonia oblonga and its extracted silver nanoparticles for improving antioxidant and antibacterial activity of 3D printed alginate-based hydrogel as wound dressing.

The current research studies the synergistic effect of Cydonia oblonga and its extracted nano bio­silver as a natural and eco-friendly agent for the improvement of three-dimensional (3D)-printed alginate wound dressings. Therefore, Cydonia oblonga extract was first prepared and silver nanoparticles were extracted from it through a green and simple method. The Cydonia oblonga and its extracted bio-based nanoparticles were then added to 3D printing alginate-based ink. Subsequently, a 3D structural extrusion printer was employed to create the porous hydrogel-based wound dressings. The morphological investigation demonstrated that using the extraction method the bio-based silver nanoparticles were successfully prepared, having an average size of 17.95 ± 4.50 nm. The Cydonia oblonga extract showed comparable antioxidant activity to the commercial antioxidant and an excellent total phenol content. In addition, the results showed the combination of Cydonia oblonga extracts/silver nanoparticles significantly improved the antibacterial performance of alginate-based bioinks. In vivo, and in vitro studies confirmed their biocompatibility and significant efficacy in the treatment of burn wounds.

Nitinol: From historical milestones to functional properties and biomedical applications.

Isoatomic NiTi alloy (Nitinol) has become an important biomaterial due to its unique characteristics, including shape memory effect, superelasticity, and high damping. Nitinol has been widely used in the biomedical field, including orthopedics, vascular stents, orthodontics, and other medical devices. However, there have been convicting views about the biocompatibility of Nitinol. Some studies have shown that Nitinol has extremely low cytotoxicity, indicating Nitinol has good biocompatibility. However, some studies have shown that the in-vivo corrosion resistance of Nitinol significantly decreases. This comprehensive paper discusses the historical developments of Nitinol, its biomedical applications, and its specific functional property. These render the suitability of Nitinol for such biomedical applications and provide insights into its in vivo and in vitro biocompatibility in the physiological environment and the antimicrobial strategies that can be applied to enhance its biocompatibility. Although 3D metal printing is still immature and Nitinol medical materials are difficult to be processed, Nitinol biomaterials have excellent potential and commercial value for 3D printing. However, there are still significant problems in the processing of Nitinol and improving its biocompatibility. With the deepening of research and continuous progress in surface modification and coating technology, a series of medical devices made from Nitinol are expected to be released soon.

Improving the corrosion behavior of magnesium alloys with a focus on AZ91 Mg alloy intended for biomedical application by microstructure modification and coating.

Magnesium alloys such as AZ91 have received much attention due to their attractive properties, including biocompatibility and lightness. Although magnesium is a potential candidate for implant application, due to its rapid degradation in the physiological environment, there are still some challenges to using it as biocompatible implants. In this regard, various techniques such as microstructure modification and coating are utilized to moderate the degradation rate of magnesium alloys. Therefore, efforts are being made to conduct more extensive research to produce magnesium implants with acceptable corrosion resistance. In this literature review, an overview of the history of research on the corrosion behavior, biodegradability, microstructure deformation mechanisms, crystallographic texture in magnesium alloys with a focus on AZ91 Mg alloy, is provided. In addition, the necessity of improving the properties of AZ91 Mg alloy by the two methods of improving microstructure and coating, and existing innovations in these methods are investigated.

Innovations in Drug Delivery for Chronic Wound Healing.

Wound healing is a varied and complex process designed to restore normal skin structure, function, and appearance in a timely manner. To achieve this goal, different immune and biological systems participate in coordination through four separate steps, including homeostasis, inflammation, proliferation, and regeneration. Each step involves the function of different cells, cytokines, and growth factors. However, chronic ulcers, which are classified into three types of ulcers, namely vascular ulcers, diabetic ulcers, and pressure ulcers, are not able to heal through the mentioned natural stages. This, in turn, causes mental and physical problems for these people and, as a result, imposes high economic and social costs on the society. In this regard, using a system that can accelerate the healing process of such chronic wounds, as an urgent need in society, should be considered. Therefore, in this study, the innovations of drug delivery systems for the healing of chronic wounds using hydrogels, nanomaterials, and membranes are discussed and reviewed.