1. BIOINSPIRED ORGANIC-INORGANIC COMPOSITE MATERIALS
Egemen Deniz Eren1,2, Mustafa O. Guler1,2
1UNAM - National Nanotechnology Research Center, Bilkent University, Ankara, Turkey
2Institute of Materials Science and Nanotechnology, Bilkent University, Ankara, Turkey
INTRODUCTION
TUNABLE MECHANICS OF PEPTIDE GELS
Hierarchical structure of human cortical bone. Bone and other natural materials are able to generate their unique combination of strength and toughness from their hierarchical structure spanning nano- to macro-scale features. The dense cortical bone is mainly found within the diaphysis of long bones and the shell surrounding the porous trabecular bone.
Magnetotactic bacteria (MTB) are a diverse group of microorganisms with the ability to orient and migrate along geomagnetic field lines. This unique feat is based on specific intracellular organelles, the magnetosomes, which, in most MTB, comprise nanometer-sized, membrane bound crystals of magnetic iron minerals and organized into chains via dedicated cytoskeleton.
Biomineralized peptide amphiphile nanofibers can be observed by TEM and AFM.
Sketch of bivalve molluscan anatomy indicates the position of the liquid-filled interlamellar space between the mineralized shell and the mantle part of the soft body of the organism and illustrates with successive amplifications the brick and mortar structure of nacre.
Type of biominerals can be determined by XRD, and Inorganic / Organic ratio can be calculated by TGA. It can be seen that hydroxyapatite crystals and calcite are formed inside the organic structure. In addition, Storage Moduli of composite materials are superior compared to non-mineralized peptide nanofibers.
Negatively charged Lauryl-VVAGEEE was used as template for biomineralization.
Structural alterations can be observed by SEM images.
TUNABLE MECHANICS OF PEG / PEPTIDE COMPOSITE HYDROGELS
There are several parameters such as mechanical properties and bioactivity, which play important roles in cell migration, differentiation, spreading and contraction. In order to enhance the mechanical properties of the materials, biomineralization approach can be used. We will enhance the mechanical properties of polymer-peptide composite hydrogels by combining biominerals inside the hydrogel network.
Experimental route of synthesizing PEG/PA composite hydrogel.
After mineralization
Live/dead micrographs of Saos-2 cells encapsulated within
three-dimensional (top) PEG (w/o PA nanofibers) and (bottom)
nanofibrous RGD/PEG composite scaffolds at day 7.
Only PA Hydrogel
CONCLUSIONS
In conclusion, synthesis of biomineralized peptide nanofibers and PEG/PA composite hydrogels is presented. By incorporating biominerals into the structure of hydrogel networks, improvement of mechanical properties was achieved. While PEG/PA composite hydrogels show remarkable properties in terms of mimicking extracellular matrix, we believe that mineralized PEG/PA composite hydrogels could show the same properties.
REFERENCES
FUNDING
[1] Adv. Healthcare Mater. 2015, DOI: /adhm
[2] Microbiological Research 167 (2012) 507–519
[3] Goktas, M., Cinar, G., Orujalipoor, I., Ide, S., Tekinay, A.B., Guler, M.O., “Self-Assembled Peptide Amphiphile Nanofibers and PEG Composite Hydrogels as Tunable ECM Mimetic Microenvironment”, Biomacromolecules, 2015, 16, 1247.
[4] Evans, J. S. “ Tuning in ” to Mollusk Shell Nacre- and Prismatic-Associated Protein Terminal Sequences . Implications for Biomineralization and the Construction of High Performance Inorganic - Organic Composites. 4455–4462 (2008).
TÜBİTAK
213M406
113M900