Investigators at John Hopkins Medical Institute have built nanoscale fiber scaffolds that could facilitate cartilage repair.
Cartilage is the shock-absorbing lining present in elbows and knees. The lining often wears thin with age or injury. The team of tissue engineers from John Hopkins University is trying to build a template that replicates the natural environment of cartilage cells in order to capitalize on nature’s way of repairing damaged cartilage.
The template is a three dimensional combination of protein fibers and gel which can support connective tissues in the body along with biological and physical signals for cells to develop and differentiate.
A nano-fiber network is created by a process called electrospinning, in which a polymer stream is shot off into a charged platform. A growth trigger is included in the form of chondroitin sulfate, a compound commonly found in joint supplements. The scaffolds were then engineered from this spun polymer. The response of stem cells to the scaffold material was determined by seeding stem cells derived from goat bone marrow into the scaffolds. The team found that stem cells in the scaffold developed into cartilage-like tissue.
The system was tested in rats by infusing the nanofiber scaffolds into damaged cartilage in rat knees. The comparison in tissue development and repair between knees with scaffolds and knees without scaffold was done by measuring the production of collagen, a vital component of cartilage. The team found that higher amounts of type 2 collagen were produced in knees with scaffolds. Type 2 collagen is considered to increase the durability of cartilage as opposed to the type 1 collagen produced in scar tissue formed during unassisted healing. Though the technique cannot be applied immediately in human beings, it forms the foundation for new techniques to combat joint pain.