Chondroitin sulfate (CS) is a natural macromolecule polysaccharide that is extensively distributed in a wide variety of organisms. CS is of great interest to researchers due to its many in vitro and in vivo functions. CS production derives from a diverse number of sources, including but not limited to extraction from various animals or fish, bio-synthesis, and fermentation, and its purity and homogeneity can vary greatly. The structural diversity of CS with respect to sulfation and saccharide content endows this molecule with distinct complexity, allowing for functional modification. These multiple functions contribute to the application of CS in medicines, biomaterials, and functional foods. In this article, we discuss the preparation of CS from different sources, the structure of various forms of CS, and its binding to other relevant molecules. Moreover, for the creation of this article, the functions and applications of CS were reviewed, with an emphasis on drug discovery, hydrogel formation, delivery systems, and food supplements. We conclude that analyzing some perspectives on structural modifications and preparation methods could potentially influence future applications of CS in medical and biomaterial research.

This study deliberated the effect of ultrasonic treatment on collagen self-assembly behavior and collagen fibril gel properties. Bovine bone collagen I which had undergone ultrasonic treatment with different power (0–400 W) and duration (0–60 min) was analyzed. SDS-PAGE and spectroscopic analysis revealed that ultrasonic treatment decreased collagen molecular order degree and the number of hydrogen bonds, stretching collagen telopeptide regions while maintaining the integrity of the collagen triple-helical structure. Ultrasonic treatment (p ≤ 200 W, t ≤ 15 min) dispersed the collagen aggregates more evenly, and accelerated collagen self-assembly rate with a decreased but more homogeneous fibril diameter (82.78 ± 16.47–115.52 ± 19.51 nm) and D-periodicity lengths (62.1 ± 2.9–66.5 ± 1.8 nm) than that of the untreated collagen (119.15 ± 27.89 nm; 66.5 ± 1.8 nm). Meanwhile, ultrasonic treatment (p ≤ 200 W, t ≤ 15 min) decreased the viscoelasticity index and gel strength, enhancing thermal stability and promoting specific surface area and porosity of collagen fibril gels than that of the untreated collagen fibril gel. These results testified that collagen self-assembly behavior and collagen fibril gel properties can be regulated by ultrasonic treatment through multi-hierarchical structural alteration. This study provided a new approach for controlling in vitro collagen fibrillogenesis process so as to manufacture novel desirable collagen-based biomaterials with propitious performances for further valorization.