A Review of Cartilage Defect Treatments Using Chitosan Hydrogels in Experimental Animal Models.

INTRODUCTION: Chitosan (CS) is a polycationic polysaccharide comprising glucosamine and N-acetylglucosamine and constitutes a potential material for use in cartilage tissue engineering. Moreover, CS hydrogels are able to promote the expression of cartilage matrix components and reduce inflammatory and catabolic mediator production by chondrocytes. Although all the positive outcomes, no review has analyzed the effects of CS hydrogels on cartilage repair in animal models. METHODS: This study aimed to review the literature to examine the effects of CS hydrogels on cartilage repair in experimental animal models. The search was done by the descriptors of the Medical Subject Headings (MeSH) defined below: "Chitosan," "hydrogel," "cartilage repair," and "in vivo." A total of 420 articles were retrieved from the databases Pubmed, Scopus, Embase, Lilacs, and Web of Science. After the eligibility analyses, this review reported 9 different papers from the beginning of 2002 through the middle of 2022. RESULTS: It was found that cartilage repair was improved with the treatment of CS hydrogel, especially the one enriched with cells. In addition, CS hydrogel produced an upregulation of genes and proteins that act in the cartilage repair process, improving the biomechanical properties of gait. CONCLUSION: In conclusion, CS hydrogels were able to stimulate tissue ingrowth and accelerate the process of cartilage repair in animal studies.

Terpenes extracted from marine sponges with antioxidant activity: a systematic review.

Marine biodiversity has emerged as a very promising resource of bioactive compounds and secondary metabolites from different sea organisms. The sponge's secondary metabolites demonstrated various bioactivities and potential pharmacological properties. This systematic review of the literature focuses on the advances achieved in the antioxidant potential of marine sponges in vitro. The review was performed in accordance with PRISMA guidelines. The main inclusion criterion for analysis was articles with identification of compounds from terpene classes that demonstrate antioxidant activity in vitro. Searching in three different databases, two hundred articles were selected. After screening abstracts, titles and evaluating for eligibility of manuscripts 14 articles were included. The most performed analyzes to detect antioxidant activity were scavenging activity 2,2-diphenyl-1-picrylhydrazyl (DPPH) and measurement of intracellular reactive oxygen species (ROS). It was possible to identify 17 compounds of the terpene class with pronounced antioxidant activity in vitro. Scientific evidence of the studies included in this review was accessed by the GRADE analysis. Terpenes play an important ecological role, moreover these molecules have a pharmaceutical and industrial application.