Human nasal septal chondrocytes (NSCs) preconditioned on NSC-derived matrix improve their chondrogenic potential

Porcine nasal septum cartilage-derived decellularized matrix promotes chondrogenic differentiation of human umbilical mesenchymal stem cells without exogenous growth factors

BACKGROUND

In the domain of plastic surgery, nasal cartilage regeneration is of significant importance. The extracellular matrix (ECM) from porcine nasal septum cartilage has shown potential for promoting human cartilage regeneration. Nonetheless, the specific biological inductive factors and their pathways in cartilage tissue engineering remain undefined.

METHODS

The decellularized matrix derived from porcine nasal septum cartilage (PN-DCM) was prepared using a grinding method. Human umbilical cord mesenchymal stem cells (HuMSCs) were cultured on these PN-DCM scaffolds for 4 weeks without exogenous growth factors to evaluate their chondroinductive potential. Subsequently, proteomic analysis was employed to identify potential biological inductive factors within the PN-DCM scaffolds.

RESULTS

Compared to the TGF-β3-cultured pellet model serving as a positive control, the PN-DCM scaffolds promoted significant deposition of a Safranin-O positive matrix and Type II collagen by HuMSCs. Gene expression profiling revealed upregulation of ACAN, COL2A1, and SOX9. Proteomic analysis identified potential chondroinductive factors in the PN-DCM scaffolds, including CYTL1, CTGF, MGP, ITGB1, BMP7, and GDF5, which influence HuMSC differentiation.

CONCLUSION

Our findings have demonstrated that the PN-DCM scaffolds promoted HuMSC differentiation towards a nasal chondrocyte phenotype without the supplementation of exogenous growth factors. This outcome is associated with the chondroinductive factors present within the PN-DCM scaffolds.

Regenerated silk fibroin based on small aperture scaffolds and marginal sealing hydrogel for osteochondral defect repair

BACKGROUND

Osteochondral defects pose an enormous challenge without satisfactory repair strategy to date. In particular, the lateral integration of neo-cartilage into the surrounding native cartilage is a difficult and inadequately addressed problem determining tissue repair's success.

METHODS

Regenerated silk fibroin (RSF) based on small aperture scaffolds was prepared with n-butanol innovatively. Then, the rabbit knee chondrocytes and bone mesenchymal stem cells (BMSCs) were cultured on RSF scaffolds, and after induction of chondrogenic differentiation, cell-scaffold complexes strengthened by a 14 wt% RSF solution were prepared for in vivo experiments.

RESULTS

A porous scaffold and an RSF sealant exhibiting biocompatibility and excellent adhesive properties are developed and confirmed to promote chondrocyte migration and differentiation. Thus, osteochondral repair and superior horizontal integration are achieved in vivo with this composite.

CONCLUSIONS

Overall, the new approach of marginal sealing around the RSF scaffolds exhibits preeminent repair results, confirming the ability of this novel graft to facilitate simultaneous regeneration of cartilage-subchondral bone.

The role of cellular traction forces in deciphering nuclear mechanics

Cellular forces exerted on the extracellular matrix (ECM) during adhesion and migration under physiological and pathological conditions regulate not only the overall cell morphology but also nuclear deformation. Nuclear deformation can alter gene expression, integrity of the nuclear envelope, nucleus-cytoskeletal connection, chromatin architecture, and, in some cases, DNA damage responses. Although nuclear deformation is caused by the transfer of forces from the ECM to the nucleus, the role of intracellular organelles in force transfer remains unclear and a challenging area of study. To elucidate nuclear mechanics, various factors such as appropriate biomaterial properties, processing route, cellular force measurement technique, and micromanipulation of nuclear forces must be understood. In the initial phase of this review, we focused on various engineered biomaterials (natural and synthetic extracellular matrices) and their manufacturing routes along with the properties required to mimic the tumor microenvironment. Furthermore, we discussed the principle of tools used to measure the cellular traction force generated during cell adhesion and migration, followed by recently developed techniques to gauge nuclear mechanics. In the last phase of this review, we outlined the principle of traction force microscopy (TFM), challenges in the remodeling of traction forces, microbead displacement tracking algorithm, data transformation from bead movement, and extension of 2-dimensional TFM to multiscale TFM.