Synthesis of highly porous crosslinked elastin hydrogels and their interaction with fibroblasts in vitro.

School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, NSW 2006, Australia.
Biomaterials (Impact Factor: 8.31). 07/2009; 30(27):4550-7. DOI: 10.1016/j.biomaterials.2009.05.014
Source: PubMed

ABSTRACT In this study the feasibility of using high pressure CO2 to produce porous alpha-elastin hydrogels was investigated. Alpha-elastin was chemically crosslinked with hexamethylene diisocyanate that can react with various functional groups in elastin such as lysine, cysteine, and histidine. High pressure CO2 substantially affected the characteristics of the fabricated hydrogels. The pore size of the hydrogels was enhanced 20-fold when the pressure was increased from 1 bar to 60 bar. The swelling ratio of the samples fabricated by high pressure CO2 was also higher than the gels produced under atmospheric pressure. The compression modulus of alpha-elastin hydrogels was increased as the applied strain magnitude was modified from 40% to 80%. The compression modulus of hydrogels produced under high pressure CO2 was 3-fold lower than the gels formed at atmospheric conditions due to the increased porosity of the gels produced by high pressure CO2. The fabrication of large pores within the 3D structures of these hydrogels substantially promoted cellular penetration and growth throughout the matrices. The highly porous alpha-elastin hydrogel structures fabricated in this study have potential for applications in tissue engineering.

  • [Show abstract] [Hide abstract]
    ABSTRACT: Tissue scaffolds play a vital role in tissue engineering by providing a native tissue-mimicking environment for cells, with the aim to promote cell proliferation, proper cell differentiation, and regeneration. To better mimic the microenvironment of native tissues, novel techniques and materials have emerged in recent years. Among them, hydrogels formed from self-assembled biopolymer networks are particularly interesting. This paper reviews the fabrication and use of fibrous protein-based hydrogels, with an emphasis on silk, keratin elastin and resilin proteins. Hydrogels formed by these proteins show close structural, chemical and mechanical similarities with the extracellular matrix, typically good biological compatibility, and they can trigger specific cellular responses. In addition, these hydrogels can be degraded in the body by proteolytic enzymes. For these reasons, fibrous protein hydrogels are one of the most versatile materials for tissue engineering.
    Biomaterials 05/2014; · 8.31 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Biocompatible and biodegradable porous materials based on silk fibroin, a natural protein derived from the Bombyx mori silkworm, are being extensively investigated for use in biomedical applications including mammalian cell bioprocessing, tissue engineering, and drug delivery applications. In this work, low-pressure, gaseous CO2 is used as an acidifying agent to fabricate silk fibroin hydrogels. This low-pressure CO2 acidification method is compared to an acidification method using high-pressure CO2 to demonstrate the effect of CO2 mass transfer and pressure on silk fibroin sol-gel kinetics. The effect of silk fibroin molecular weight on the sol-gel kinetics is determined using the low-pressure CO2 method. The results from these studies demonstrate that low-pressure CO2 processing proves to be a facile method for synthesizing 3D silk fibroin hydrogels.
    Acta biomaterialia. 06/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Hydrogels, which have become a central component of numerous strategies in regenerative medicine, have recently been designed to include pores as a means to facilitate cell ingrowth and facilitate transport. Herein, we present the formation of macro-porous hydrogels by a novel fabrication method termed cryotemplated photopolymerization. In contrast to chemically-induced cryogelation, our cryotemplation method separates the creation of pores from the crosslinking of the polymer, which allows templating of hydrogels using both porogens and light. This method allows separately frozen pieces to be joined during the photopolymerization, without the use of a mold, to form complex architectures. The size of the pores in the hydrogels could be controlled by multiple methods, thus providing a versatile platform for numerous tissue engineering applications. Additionally, these hydrogels were capable of functionalization with peptides using techniques that did not interfere with gelation. Furthermore, porous hydrogels could be formed under conditions suitable for cell freezing thereby allowing for cell encapsulation. These studies characterize a hydrogel fabrication strategy that enables the creation of porous scaffolds in complex architectures, while retaining the potential to chemically functionalize the hydrogels.
    Journal of materials chemistry. B, Materials for biology and medicine. 07/2014; 2(28):4521-4530.


Available from
May 17, 2014