| uccess of tissue engineering for cartilage for | | | | active, less traumatic and less expensive methods |
| conditions like osteoarthritis will be dependent on the | | | | and techniques are developed for the treatment of |
| interactions between the cells, the matrix, and | | | | these diseases. The expectation is that |
| mechanical forces directed against the joint. | | | | nanotechnology will provide an important contribution |
| The extracellular matrix- the framework and the | | | | to the development of such techniques. Implants and |
| material inside the framework the stem cells cling to- | | | | tissue substitutes are made from biomaterials that |
| plays a crucial role in tissue function, dictating its | | | | have one common property, i.e. biocompatibility. A |
| physical and mechanical properties, maintaining the | | | | promising application of nanotechnology is the |
| spatial arrangement of the cells that live within it and | | | | development of better functioning biomaterials. |
| controlling the complex crosstalk that exists between | | | | A recent approach to the design of next-generation |
| the cells, the matrix and external forces. The matrix | | | | tissue regeneration supporting biomaterials is focusing |
| controls cell size, shape, movement and alignment | | | | on the structure at the "nano" scale. The underlying |
| through its three-dimensional architecture and | | | | idea is that nanometer structure matches with the |
| adhesion… the stickiness of the stem cells. | | | | natural extracellular matrix resulting in an improved |
| While the matrix exerts its effects, the cells influence | | | | interaction of the tissue-forming cells compared with |
| the matrix by applying traction forces and by | | | | conventional biomaterials. Recent developments in the |
| synthesizing and degrading matrix. In addition, the | | | | field of nanotechnology offer powerful tools to |
| interaction between the matrix and stem cells is | | | | modify the surface of biomaterials by introducing |
| responsible for triggering a variety of specific cellular | | | | artificial mapping and specific surface chemistry on |
| functions. It has become increasingly clear that the | | | | the material. It is well-known that both topography |
| mechanical environment is equally important as, and | | | | and surface chemical composition affect the reactions |
| synergistic with, the chemical environment in directing | | | | of the biological environment to the device. |
| cell behavior. | | | | Human mesenchymal stem cells occupy a particular |
| Signaling pathways spurred on in response to | | | | stem cell niche, and consist of those stem cells that |
| mechanical (load-bearing) forces are essential for the | | | | can differentiate into cells of mesenchymal tissues, |
| maintenance and function of tissue cellular function. | | | | including osteoblasts, adipocytes and chondrocytes. |
| Load-bearing soft tissues such as tendons and | | | | Osteoarthritis is the most common musculoskeletal |
| cartilage which consist of a network of fibrous | | | | disorder and causes a significant social and |
| protein (predominantly collagen and elastin), | | | | psychological drain on those affected as well as |
| embedded in a gel of proteoglycans, | | | | those who care for them; in addition it leads to |
| glycosaminoglycans and glycoproteins exhibit specific | | | | significant economic costs. This disease is |
| properties of tissue biomechanics and subsequent | | | | characterized by articular cartilage degeneration and |
| cellular responses. | | | | damage to the underlying subchondral bone. To date, |
| Investigations in these unique tissues and engineered | | | | there is a lack of effective therapies to treat the |
| are rapidly expanding our understanding of a new | | | | disease, resulting in total joint arthroplasty (joint |
| area of medicine called mechanobiology. | | | | replacement surgery) as the only viable therapeutic |
| Successful tissue engineering requires a | | | | option. Thus, there is a need to develop methods |
| comprehensive understanding of mechanobiology and | | | | that are less invasive and capable of regeneration of |
| in particular the loading conditions experienced by the | | | | articular cartilage. |
| cells under physiological conditions, in order to | | | | The use of autologous chondrocytes in tissue |
| establish how this controls cellular functions. | | | | engineering applications promises an avenue in terms |
| Clarification of mechanical pathways should provide | | | | of efficacy and safety resulting in mesenchymal stem |
| useful information for tissue engineering and | | | | cells (MSCs) being considered an ideal therapeutic |
| regenerative applications as well as further insight into | | | | candidate for cartilage repair. MSCs acting through |
| mechanisms involved in disease processes. | | | | multiple growth mechanisms are also known to |
| The population of the Western world is aging. As a | | | | prevent OA progression after injection into the joint. |
| direct consequence, there will be an increase in | | | | At our center, we are constantly incorporating newer |
| diseases that can be associated with aging, such as | | | | approaches to the introduction of stem cell |
| joint problems.. Those maladies not only have a | | | | technology for the treatment of osteoarthritis. |
| negative effect for the patient, but will also have a | | | | Our approach now is different from the way it was a |
| significant impact on the health care system. | | | | year ago... and it will be different a year from now as |
| Therefore, it is extremely important that more | | | | we learn more about nanobiology. |