Fracture in Hierarchical Biomaterials: Human Hair

Fracture of Ceramic-Polymer Composite Biomaterials

Fracture toughness, strength, and elastic modulus of poly(methyl methacrylate) (PMMA)and poly(buty1 methacrylate) (PBMA)-impregnated alumina ceramics were measured as a function of polymer volume fraction, mean polymer particle size, and interfacial bonding between the polymer and ceramic. Fracture toughness was found to increase with increasing polymer volume fraction and decreasing polymer pa...

Structure-Function Relationship of Meta-Kerateine Biomaterials Derived from Human Hair

STATEMENT OF PURPOSE Keratins have been explored as a biomaterial system for more than two decades. Recently, several potential medical applications have been identified and explored in large animal models. Most of this work has been done with films and gels made from a heterogeneous mixture of different keratin sub-types which has resulted in biomaterials of limited mechanical strength. Severa...

Hierarchical patterning modes orchestrate hair follicle morphogenesis

Two theories address the origin of repeating patterns, such as hair follicles, limb digits, and intestinal villi, during development. The Turing reaction-diffusion system posits that interacting diffusible signals produced by static cells first define a prepattern that then induces cell rearrangements to produce an anatomical structure. The second theory, that of mesenchymal self-organisation, ...

Human hair growth in vitro.

We report for the first time the successful maintenance and growth of human hair follicles in vitro. Human anagen hair follicles were isolated by microdissection from human scalp skin. Isolation of the hair follicles was achieved by cutting the follicle at the dermo-subcutaneous fat interface using a scalpel blade. Intact hair follicles were then removed from the fat using watchmakers' forceps....

A Hierarchical Approach to Fracture Mechanics