Toughened hydrogels inspired by aquatic caddisworm silk.
Soft Matter
; 11(35): 6981-90, 2015 Sep 21.
Article
em En
| MEDLINE
| ID: mdl-26234366
ABSTRACT
Aquatic caddisworm silk is a tough adhesive fiber. Part of the toughening mechanism resides in serial, Ca(2+)-phosphate crosslinked nano-domains that comprise H-fibroin, the major structural protein. To mimic the toughening mechanism, a synthetic phosphate-graft-methacrylate prepolymer, as a simple H-fibroin analog, was copolymerized within a covalent elastic network of polyacrylamide. Above a critical phosphate sidechain density, hydrogels equilibrated with Ca(2+) or Zn(2+) ions displayed greatly increased initial stiffness, strain-rate dependent yield behavior, and required 100 times more work to fracture than hydrogels equilibrated with Mg(2+) or Na(+) ions. Conceptually, the enhanced toughness is attributed to energy-dissipating, viscous unfolding of clustered phosphate-metal ion crosslinks at a critical stress. The toughness of the bioinspired hydrogels exceeds the toughness of cartilage and meniscus suggesting potential application as prosthetic biomaterials. The tough hydrogels also provide a simplified model to test hypotheses about caddisworm silk architecture, phosphate metal ion interactions, and mechanochemical toughening mechanisms.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Hidrogéis
/
Fibroínas
Idioma:
En
Ano de publicação:
2015
Tipo de documento:
Article