title: Elastin-like polypeptide based hydroxyapatite bionanocomposites.
abstract: In nature, organic matrix macromolecules play a critical role in enhancing the mechanical properties of biomineralized composites such as bone and teeth. Designing artificial matrix analogues is promising but challenging because relatively little is known about how natural matrix components function. Therefore, in lieu of using natural components, we created biomimetic matrices using genetically engineered elastin-like polypeptides (ELPs) and then used them to construct mechanically robust ELP-hydroxyapatite (HAP) composites. ELPs were engineered with well-defined backbone charge distributions by periodic incorporation of negative, positive, or neutral side chains or with HAP-binding octaglutamic acid motifs at one or both protein termini. ELPs exhibited sequence-specific capacities to interact with ions, bind HAP, and disperse HAP nanoparticles. HAP-binding ELPs were incorporated into calcium phosphate cements, resulting in materials with improved mechanical strength, injectability, and antiwashout properties. The results demonstrate that rational design of genetically engineered polymers is a powerful system for determining sequence-property relationships and for improving the properties of organic-inorganic composites. Our approach may be used to further develop novel, multifunctional bone cements and expanded to the design of other advanced composites.
authors.affiliation: Department of Bioengineering, University of California, Berkeley, Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley Nanoscience and Nanoengineering Institute, Berkeley, California 94720, USA.
authors.forename: Eddie
authors.initials: E
authors.lastname: Wang
authors.forename: Sang-Hyuk
authors.initials: SH
authors.lastname: Lee
authors.forename: Seung-Wuk
authors.initials: SW
authors.lastname: Lee
mesh_terms: D040761:Biomimetic Materials / Q000138:chemical synthesis*; D032701:Biomimetics / Q000379:methods; D018786:Bone Substitutes; D017886:Durapatite / Q000737:chemistry*; D004549:Elastin / Q000737:chemistry*; D008422:Materials Testing; D053761:Nanocomposites / Q000737:chemistry*; D010455:Peptides / Q000138:chemical synthesis*; D015202:Protein Engineering / Q000379:methods*; D055672:Static Electricity
chemical_list: D018786:Bone Substitutes; D010455:Peptides; D004549:Elastin; D017886:Durapatite