Platelet-rich plasma promotes the regeneration of cartilage engineered by mesenchymal stem cells and collagen hydrogel via the TGF-ß/SMAD signaling pathway.

The tissue engineering technique using mesenchymal stem cells (MSCs) and scaffolds is promising. Transforming growth factor-ß1 (TGF-ß1) is generally accepted as an chondrogenic agent, but immunorejection and unexpected side effects, such as tumorigenesis and heterogeneity, limit its clinical application. Autogenous platelet-rich plasma (PRP), marked by low immunogenicity, easy accessibility, and low-cost, may be favorable for cartilage regeneration. In our study, the effect of PRP on engineered cartilage constructed by MSCs and collagen hydrogel in vitro and in vivo was investigated and compared with TGF-ß1. The results showed that PRP promoted cell proliferation and gene and protein expressions of chondrogenic markers via the TGF-ß/SMAD signaling pathway. Meanwhile, it suppressed the expression of collagen type I, a marker of fibrocartilage. Furthermore, PRP accelerated cartilage regeneration on defects with engineered cartilage, advantageous over TGF-ß1, as evaluated by histological analysis and immunohistochemical staining. Our work demonstrates that autogenous PRP may substitute TGF-ß1 as a potent and reliable chondrogenic inducer for therapy of cartilage defect.

Epigallocatechin-3-gallate (EGCG) based metal-polyphenol nanoformulations alleviates chondrocytes inflammation by modulating synovial macrophages polarization.

The activation of M1-type macrophages are dominant cells secreting proinflammatory present within the inflamed synovium in the progression of osteoarthritis (OA). Increased oxidative stress, such as redundant ROS and hydrogen peroxide (H2O2), are important factors in driving macrophages to polarize into M1 type. In this study, metal-polyphenol nanoformulations (Cu-Epigallocatechin-3-gallate (Cu-EGCG) nanosheets) were synthesized through the coordination interaction between EGCG and copper ions, which possessed the antioxidant effect of EGCG and anti-inflammatory of Cu2+. Results showed that Cu-EGCG nanosheets were biocompatible and the Cu2+ could be sustained released from the nanoparticles. Cu-EGCG nanosheets with multienzyme-like antioxidative activity could effectively scavenge the excessive intracellular ROS, leading to significantly decreased expression of the pro-inflammatory cytokines, which could reduce the expression of M1-type macrophages and exhibit excellent promotion on shifting macrophages to M2 phenotypes. Moreover, the secreted factor from the cell supernatant of Cu-EGCG treated macrophages exhibited anti-inflammatory potential in chondrocytes of inflamed synovial joints. This study suggests a novel strategy for OA therapy by using metal-polyphenol nanoformulations targeting macrophages.

Carbazate modified dextrans as scavengers for carbonylated proteins.

A series of biocompatible and non- toxic polysaccharide molecules have been successfully fabricated and explored their potential application for scavenging the carbonyl species in vitro. These macromolecules were dextrans with different hydrazide substitution ratios determined by TNBS assay, NMR and FTIR characterization. The colorimetric assay had demonstrated that these macromolecules could effectively scavenge acrolein, oxidized bovine serum albumin (BSA) in buffer solutions as well as carbonyl proteins from serum. The scavengers could achieve twice more scavenging effects for modified dextrans with high molecular weight (Mw = 100,000) than those of low ones (Mw = 40,000) with the same substitution ratio. Protein gel electrophoresis confirmed that the formation of the complex between carbonyls and modified dextrans resulted in appearance of slower bands. It also revealed that such macromolecules could protect cultured cells against the toxicity of acrolein or its derivatives. The proposed macromolecules indicated a very promising capability as scavengers for oxidative stress plus its derivatives without side effects.