Recent advances in kartogenin for cartilage regeneration

Extruded Bioreactor Perfusion Culture Supports the Chondrogenic Differentiation of Human Mesenchymal Stem/Stromal Cells in 3D Porous Poly(ɛ-Caprolactone) Scaffolds

Novel bioengineering strategies for the ex vivo fabrication of native-like tissue-engineered cartilage are crucial for the translation of these approaches to clinically manage highly prevalent and debilitating joint diseases. Bioreactors that provide different biophysical stimuli have been used in tissue engineering approaches aimed at enhancing the quality of the cartilage tissue generated. However, such systems are often highly complex, expensive, and not very versatile. In the current study, a novel, cost-effective, and customizable perfusion bioreactor totally fabricated by additive manufacturing (AM) is proposed for the study of the effect of fluid flow on the chondrogenic differentiation of human bone-marrow mesenchymal stem/stromal cells (hBMSCs) in 3D porous poly(ɛ-caprolactone) (PCL) scaffolds. hBMSCs are first seeded and grown on PCL scaffolds and hBMSC-PCL constructs are then transferred to 3D-extruded bioreactors for continuous perfusion culture under chondrogenic inductive conditions. Perfused constructs show similar cell metabolic activity and significantly higher sulfated glycosaminoglycan production (≈1.8-fold) in comparison to their non-perfused counterparts. Importantly, perfusion bioreactor culture significantly promoted the expression of chondrogenic marker genes while downregulating hypertrophy. This work highlights the potential of customizable AM platforms for the development of novel personalized repair strategies and more reliable in vitro models with a wide range of applications.

Surgical and tissue engineering strategies for articular cartilage and meniscus repair

Injuries to articular cartilage and menisci can lead to cartilage degeneration that ultimately results in arthritis. Different forms of arthritis affect ~50 million people in the USA alone, and it is therefore crucial to identify methods that will halt or slow the progression to arthritis, starting with the initiating events of cartilage and meniscus defects. The surgical approaches in current use have a limited capacity for tissue regeneration and yield only short-term relief of symptoms. Tissue engineering approaches are emerging as alternatives to current surgical methods for cartilage and meniscus repair. Several cell-based and tissue-engineered products are currently in clinical trials for cartilage lesions and meniscal tears, opening new avenues for cartilage and meniscus regeneration. This Review provides a summary of surgical techniques, including tissue-engineered products, that are currently in clinical use, as well as a discussion of state-of-the-art tissue engineering strategies and technologies that are being developed for use in articular cartilage and meniscus repair and regeneration. The obstacles to clinical translation of these strategies are also included to inform the development of innovative tissue engineering approaches.

Levels of matrix metalloproteinase-2 in committed differentiation of bone marrow mesenchymal stem cells induced by kartogenin

Objective

To measure the inductive effect of kartogenin on matrix metalloproteinase-2 levels during the differentiation of human bone marrow mesenchymal stem cells (hMSCs) into chondrocytes in vitro.

Methods

In vitro cultured bone marrow hMSCs were grown to the logarithmic phase and then divided into three groups: control group (0 µM kartogenin), 1 µM kartogenin group and 10 µM kartogenin group. After 72 h of culture, cell proliferation and differentiation were observed microscopically. Matrix metalloproteinase-2 (MMP-2) in the cell supernatant and type II collagen levels in the cells were detected by enzyme linked immunosorbent assay and immunofluorescence staining, respectively.

Results

Kartogenin induced the proliferation and differentiation of hMSCs. With the increase of kartogenin concentration, the level of type II collagen was increased, while the level of MMP-2 decreased.

Conclusion

These findings indicate that kartogenin can induce hMSCs to differentiate into chondrocytes, and with the increase of kartogenin concentration, degeneration of the cartilage extracellular matrix may be inhibited.