No abstract

The regenerated silk fibroin microhydrogel with thixotropic property could be bioprinted and then ripened to a tough hydrogel because of the change in “the second network” of the microhydrogel.

To harvest silk fibroin (SF) based organic/inorganic composites with various general properties (e.g. hard or soft), the strategies of vacuum filtration and centrifugation were employed in this work to produce a film and hydrogel of SF-nanofibril/nanohydroxyapatite, respectively. It was found that the SF-nanofibril mediated the mineralization of hydroxyapatites (HAP) in situ and the morphology of such organic/inorganic nanohybrids presented a "flower-like" structure, mainly because of the strong interaction between SF-nanofibrils and nanohydroxyapatites. On the other hand, the extracellular matrix (ECM) like SF/HAP hydrogel illustrated not only an adequate mechanical strength, but also a remarkable thixotropy, with the storage modulus (G') being able to recover to 85% within 50 seconds when a large shearing strain (5000%) was applied. Moreover, the mechanical properties of these well-organized materials were adjustable for varied demands, and the whole fabrication process was simple and eco-friendly. Therefore, all results indicate that hybrids of SF-nanofibril/nanohydroxyapatite have promise in applications, particularly in bone tissue engineering.

Upgradation is still in need for the clinical-applied interference screws in anterior cruciate ligament reconstruction for more reliable fixation. Silk fibroin bulk materials offer a promising opportunity for this application...

Ivory carves well and lasts long even under heavy usage. Its use over millennia are testaments to its value for household items, high-value ornaments and weaponry as well as false teeth and early hipreplacements. Indeed, exceptional toughness is required of the elephant's ivory because its tusk is used by the animal to leverage trees to breaking point or act as weapon in fights between bulls the size and weight of trucks. A number of studies have shown elephant ivory to be a highly non-isotropic material with complex 3 dimensional structures and network of porosity. Combined, these properties give ivory its qualities so desirable by carvers, pianists, artists and pool players. In this brief overview we focus on the structures and material properties of elephant ivory, many of which are shared by other types of ivories.