Tissue Scaffold News

Tissue and organ replacement--regenerative medicine--is dependent on new developments in stem cells, growth factors, genetic controls, and tissue scaffolds. One approach to tissue scaffold uses nano-polymers.

David Nisbet from Monash University's Department of Materials Engineering has used existing polymer-based biodegradable fibres, 100 times smaller than a human hair, and re-engineered them to create a unique 3-D scaffold that could potentially allow stem cells to repair damaged nerves in the human body more quickly and effectively.

Mr Nisbet said a combined process of electrospinning and chemical treatment was used to customise the fibre structure, which can then be located within the body.

"The scaffold is injected into the body at the site requiring nerve regeneration. We can embed the stem cells into the scaffold outside the body or once the scaffold is implanted. The nerve cells adhere to the scaffold in the same way ivy grips and weaves through a trellis, forming a bridge in the brain or spinal cord. Over time, the scaffold breaks down and is naturally passed from the body, leaving the newly regenerated nerves intact," Mr Nisbet said.___Source

Certainly polymer based scaffolding can be generated quickly, and modified relatively easily. I will be interested to follow developments from this approach.

A special award was given recently to a Yale researcher involved in tissue scaffold development.

Erin Lavik, an assistant professor of biomedical engineering at Yale, was honored recently by the Connecticut Technology Council as one of their 2008 Women of Innovation....Lavik, who was cited for her academic innovation and leadership, focuses her research on developing new therapeutic approaches for the treatment of spinal cord injury and retinal degeneration.

She begins repair of damaged tissues using biodegradable polymers formed into three-dimensional scaffolds that mimic the structure of the tissue. After chemically modifying the scaffold surfaces, she incorporates growth factors that further create an environment for repair.

By combining neural or retinal stem cells with these environments, she is discovering the cues that promote integration and differentiation of the cells into healthy tissue. In a rodent model of spinal cord injury, the seeded scaffold promoted functional recovery allowing the rats to regain a weight-bearing stride. She also collaborated on an implantable system that can form and stabilize a functional network of fine blood vessels critical for supporting tissues in the body.___Eurekalert

Tissue scaffolds are routinely subjected to a variety of testing, in order the achieve the proper combination of properties of mechanics and permeability.

Deformable scaffolds with specific mechanical properties were made by blending flexible, biodegradable polymers.3,4 Labyrinths of pores with specific shapes and interconnectivity were formed into cube-shaped samples using injection molding and 3D printing.5 These prototypes were then cyclically distorted to varying degrees and in several ways: compressed or twisted, for instance. Micro x-ray imaging followed the movement of a contrast dye through the scaffolds as they were manipulated.___Source

Current scaffold-like products being used in the OR include Apligraf, Alloderm, among a growing list of synthetic tissue graft and scaffold products.

The "inkjet" approach to printing tissue and tissue scaffolds is also an active area of research in regenerative medicine--although not ready for the OR yet. The time is certainly coming, when most human organs and tissues will be replaceable with lab-grown stand-ins. We do not need anything fancy. Just something that works.