Pound for pound (or gram for gram), typical spider silk is 20 times as strong as steel and four times as tough as Kevlar. It is also extremely flexible, stretching up to 50 per cent of its length without breaking. Now, research has found that it's not just the silk's physical properties that are impressive. It elicits no immune reaction in our bodies, it is biodegradable, and it is produced at low temperatures and pressures relative to other polymers. Here is a sampling of some of the research into the practical applications oft this amazing material:
www.sciencedirect.com
Researchers are also developing "meltable electronics" designed to become part of the fabric of living tissue. Last year, they demonstrated that silk could be used to deliver ultra-thin electronics directly onto the surface of the brain, a capability which could one day be used to diagnose epilepsy or improve brain-computer interfaces. Silk films offer a much more useful surface on which to embed electronics than traditional silicon wafers as they can conform to the contours of the brain without damaging tissue. The idea is that once in place, the silk is dissolved with salt water and broken down by the surrounding tissue. Capillary forces between the silk and brain tissue help the electronics to wrap around the brain.
www.nature.com
Electronics that are capable of intimate, non-invasive integration with the soft, curvilinear surfaces of biological tissues offer important opportunities for diagnosing and treating disease and for improving brain/machine interfaces. This article describes a material strategy for a type of bio-interfaced system that relies on ultrathin electronics supported by bioresorbable substrates of silk fibroin. Mounting such devices on tissue and then allowing the silk to dissolve and resorb initiates a spontaneous, conformal wrapping process driven by capillary forces at the biotic/abiotic interface. Specialized mesh designs and ultrathin forms for the electronics ensure minimal stresses on the tissue and highly conformal coverage, even for complex curvilinear surfaces, as confirmed by experimental and theoretical studies. In vivo, neural mapping experiments on feline animal models illustrate one mode of use for this class of technology. These concepts provide new capabilities for implantable and surgical devices.
www.sciencedirect.com
A silk-fiber matrix was studied as a suitable material for tissue engineering anterior cruciate ligaments (ACL). The matrix was successfully designed to match the complex and demanding mechanical requirements of a native human ACL, including adequate fatigue performance. This protein matrix supported the attachment, expansion and differentiation of adult human progenitor bone marrow stromal cells based on scanning electron microscopy, DNA quantitation and the expression of collagen types I and III and tenascin-C markers. The results support the conclusion that properly prepared silkworm fiber matrices, aside from providing unique benefits in terms of mechanical properties as well as biocompatibility and slow degradability, can provide suitable biomaterial matrices for the support of adult stem cell differentiation toward ligament lineages. These results point toward this matrix as a new option for ACL repair to overcome current limitations with synthetic and other degradable materials.In the TED video below, Cheryl Hayashi studies spider silk, one of nature's most high-performance materials. Each species of spider can make up to 7 very different kinds of silk. How do they do it? Hayashi explains at the DNA level then shows us how this super-strong, super-flexible material can inspire.
http://nextbigfuture.com
0 comments:
Post a Comment