Many of us have used Band-Aids to heal a scratch on the surface of the skin, but imagine an internal bandage that can build itself inside our bodies to help repair damaged tissues. Researchers in the lab of Knight Campus assistant professor of bioengineering Gabriella Lindberg are exploring this possibility for cartilage regeneration.

The research is detailed in the paper "3D-Bioassembly of VH-Spheroids for Cartilage Regeneration: in Vitro Evaluation of Chondrogenesis, Fusion and Lateral Integration," which appears in the Nov. 3 edition of the journal Advanced Materials Interfaces.

"The ultimate goal of stimulating cartilage growth is to help patients with degenerative joint diseases such as osteoarthritis," said Lindberg, the senior author on the paper.

Cartilage remains very challenging to restore, many cell-therapies and implant technologies are not yet consistently successful due to poor bridging between the native and repair tissue. The therapy at the center of the new research involves so-called vitreous-humor (VH) spheroids, collections of cartilage regenerating cells and proteins encased in a spherical shaped gel to support tissue healing.

“Vitreous-humor is an exciting natural material that we are still learning more and more about when it comes to its ability to heal cartilage tissue,” Lindberg said. “Especially how we can use VH spheroids to help osteoarthritic patients respond better to cell-based therapies.”

By taking advantage of the biologically active nature of vitreous-humor spheroids, together with modern stem cell technologies, the Lindberg lab found that the spheroids were highly effective in directing new cartilage tissue growth.

“Using VH spheroids, we are hitting two birds with one stone,” Lindberg said. “We can guide cells to grow new cartilage tissue within implants while further encouraging cell to migrate across to adjacent tissues to integrate with the host cartilage”.

An example of the biological activity maintained by vitreous-humor spheroids is observed as stem cells were able to build up new cartilage to form a bridge to the native cartilage tissue in need of repair. This bridging, or integration, is key in allowing effective signaling between the bioactive spheroid technology and the original, damaged tissue, leading to tissue repair and mechanical stability.

The Lindberg lab demonstrates that vitreous-humor spheroids containing stem cells can effectively promote interactions between cells and mature tissues, creating an internal Band-Aid that fuses and integrates directly into healthy cartilaginous tissue. In the future, the Lindberg lab hopes to explore other musculoskeletal tissues such as bone with the goal of making treatments more effective and accessible.

“We hope to develop treatments that work across different patient populations, to specifically help patients that don’t respond to cell therapy to become responders and have better outcomes,” Lindberg said.

Header Image Caption: Illustration of "self-assembled vitreous humor (VH) spheroids" collections of cartilage regenerating cells and proteins that could potentially to help repair damaged tissues (Illustration by Chakris Kussalanant).