In order to replace age-damage tissue, the medical community must develop the skills and infrastructure to reliably form new, undamaged organs from our own cells and grow tissue to order in situ, inside our bodies. The field of tissue engineering is enjoying the benefits of funding, understanding and widespread support at the present time; research communities are rife with innovation and progress, and practical application of the underlying science is moving rapidly. A few examples of present lines of research:

Stem cells for tissue engineering of articular cartilage:

Tissue engineering is a recently developed science that merges the fields of cell biology, engineering, material science, and surgery to regenerate new functional tissue. Three critical components in tissue engineering of cartilage are as follows: first, sufficient cell numbers within the defect, such as chondrocytes or multipotent stem cells capable of differentiating into chondrocytes; second, access to growth and differentiation factors that modulate these cells to differentiate through the chondrogenic lineage; third, a cell carrier or matrix that fills the defect, delivers the appropriate cells, and supports cell proliferation and differentiation.

Stem Cells In Tendons That Regenerate Tissue Identified In Animal Model:

Clinically, tendon injury is a difficult one to treat, not only for athletes but for patients who suffer from tendinopathy such as tendon rupture or ectopic ossification. This research demonstrates that we can use stem cells to repair tendons. We now know how to collect them from tissue and how to control their formation into tendon cells.

Design of Tissue Engineering Scaffolds as Delivery Devices for Mechanical and Mechanically Modulated Signals:

Defining tissue template specifications to mimic the environment of the condensed mesenchyme during development allows for exploitation of tissue scaffolds as delivery devices for extrinsic cues, including biochemical and mechanical signals, to drive the fate of mesenchymal stem cells seeded within. ... As the range of mechanical signals conducive to guiding cell fate in situ is further elucidated, these refined design criteria can be integrated into the general optimization rubric, providing a technological platform to exploit nature's endogenous tissue engineering strategies for targeted tissue generation in the lab or the clinic.

Concepts of scaffold-based tissue engineering-the rationale to use solid free-form fabrication techniques

A paradigm shift is taking place in orthopaedic and reconstructive surgery from using medical devices and tissue grafts to a tissue engineering approach that uses biodegradable scaffolds combined with cells or biological molecules to repair and/or regenerate tissues. One of the potential benefits offered by solid free-form fabrication technology (SFF) is the ability to create scaffolds with highly reproducible architecture and compositional variation across the entire scaffold, due to its tightly controlled computer-driven fabrication.

Reconstruction of functional tissues with cell sheet engineering:

We have developed an approach that uses culture surfaces grafted with the temperature-responsive polymer [that] allows for controlled attachment and detachment of living cells via simple temperature changes. Using cultured cell sheets harvested from temperature-responsive surfaces, we have established cell sheet engineering to create functional tissue sheets to treat a wide range of diseases from corneal dysfunction to esophageal cancer, tracheal resection, and cardiac failure. Additionally, by exploiting the unique ability of cell sheets to generate three-dimensional tissues composed of only cultured cells and their deposited extracellular matrix, we have also developed methods to create thick vascularized tissues as well as organ-like systems for the heart and liver.

Building anything is "just" a matter of moving the right molecules to the right place - today a matter of understanding how to put blood vessels into grown segments of heart tissue, tomorrow building a complete kidney from scratch, nanostructures all complete and in the right place. Present trends in biotechnology and other branches of applied science see us becoming ever better at these tasks in the years ahead. Remember that medicine is a form of engineering; the repair, refit and replacement of biological systems is one important path to the future of longer, healthier lives.

Technorati tags: biotechnology, tissue engineering

Posted by Reason at September 10, 2007 9:49 PM | TrackBack (0)