Protein-based materials Elastic model proteins

Furthermore, patients with spinal cord injuries have a high incidence of pressure ulcers and is a population that reaches beyond nursing homes and hospitals. It has been reported that 40% of this group develops pressure ulcers during initial hospitalization and rehabilitation. In fact, all populations dependent on assistive devices where soft tissue is compressed between a bony prominence and the assistive device are at increased risk for pres-sure ulcer formation. Again as discussed below, elastic protein-based materials are being tested in an appropriate animal model, and preliminary results are promising. 

Figure 9.27. Strabismus surgery model of F. Elsas in the rabbit eye for the prevention of postsurgical adhesions due to positioning a bioelastic sleeve of elastic protein-based material between rectus muscle capsule and scleral defects. (Reproduced with permission from Urry et al. )...

Figure 9.29. Demonstration of the efficacy, in a strabismus surgery model in the rabbit eye created by F. Elsas, of a bioelastic sleeve of an elastic protein-based material to prevent adhesion between scleral...

The mechanical properties of protein-based materials are substantially lower than those of standard synthetic materials, such as polyvinylidene chloride (PVDC) or polyester (Table 11.11). The mechanical properties of protein-based materials were measured and modelled as a function of film characteristics [74, 131, 132]. For stronger materials (e.g., based on wheat gluten, corn gluten and myofibrillar proteins, critical deformation (DC) = 0.7 mm) and elastic modulus (K = 510 N/m) values are slightly lower than those of reference materials such as LDPE (DC = 2.3 mm, K = 135 N/m), cellulose (DC = 3.3 mm, K = 350 N/m) or even PVC films. The mechanical properties of corn gluten-based material are close to those of PVC. 

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