Functionalized magnesium alloys obtained by superplastic forming process retain osteoinductive and antibacterial properties: An in-vitro study.

OBJECTIVES: This study aimed to investigate the biocompatibility, osteogenic and antibacterial activity of biomedical devices based on Magnesium (Mg) Alloys manufactured by Superplastic Forming process (SPF) and subjected to Hydrothermal (HT) and Sol-Gel Treatment (Sol-Gel). METHODS: Mg-SPF devices subjected to Hydrothermal (Mg-SPF+HT) and Sol-Gel Treatment (Mg-SPF+Sol-Gel) were investigated. The biocompatibility of Mg-SPF+Sol-Gel and Mg-SPF+HT devices was observed by indirect and direct cytotoxicity assays, whereas the colonization of sample surfaces was assessed by confocal microscopy. qRT-PCR analysis and microbial growth curve analyses were employed to evaluate the osteogenic and antibacterial activity of both SPF-Mg treated devices, respectively. RESULTS: Mg-SPF+HT and Mg-SPF+Sol-Gel showed a high degree of biocompatibility. Analysis of mRNA expression of osteogenic genes in cells cultured on Mg-treated devices revealed a significant upregulation of the expression levels of BMP2 and Runx-2. Furthermore, the bacterial growth in strains developed in contact with both the Mg-SPF+HT and Mg-SPF+Sol-Gel devices was lower than that observed in the control. SIGNIFICANCE: Hydrothermal and Sol-Gel Treatments of Mg alloys obtained through the SPF process demonstrated bioactive, osteogenic and antibacterial activity, offering a promising alternative to conventional Mg-based devices. The obtained Mg-based materials may have the potential to enhance the tunability of temporary devices in maxillary reconstruction, eliminating the need for second surgeries, and ensuring a good bone reconstruction and a reduced implant failure rate due to bacterial infections.

Critical Overview on Pure Chitosan-based Scaffolds for Bone Tissue Engineering: Clinical insights in Dentistry.

Bone Tissue Engineering (BTE) is a field of regenerative medicine continuously improving, thanks to the development of new biomaterials used as grafts or scaffolds for repairing bone defects. In recent years, chitosan, a natural biopolymer extracted mainly from crustacean shells, has demonstrated unique and desirable characteristics for BTE applications, such as: biocompatibility, biodegradability, and osteoconductive behavior. Additionally, the presence of numerous active amine groups in its chemical structure allows it to be easily modified. Data suggest that chitosan scaffolds are highly biomimetic, and show an interesting bioactivity, and antibacterial behavior. We have demonstrated, in a critical overview, how chitosan-based scaffolds may hold great interest for BTE applications in medical and dental applications. Future research should be focused on the use of chitosan-scaffolds combined with other biomaterials or bioactive molecules, to increase their overall regenerative potential, also in critical-sized defects. In conclusion, chitosan can be considered a promising biomaterial in BTE and clinical dentistry.