Biomimetic materials for tissue engineering

Abstract

Tissue engineering and regenerative medicine is an exciting research area that aims at regenerative alternatives to harvested tissues for transplantation. Biomaterials play a pivotal role as scaffolds to provide three-dimensional templates and synthetic extracellular-matrix environments for tissue regeneration. It is often beneficial for the scaffolds to mimic certain advantageous characteristics of the natural extracellular matrix, or developmental or would healing programs. This article reviews current biomimetic materials approaches in tissue engineering. These include synthesis to achieve certain compositions or properties similar to those of the extracellular matrix, novel processing technologies to achieve structural features mimicking the extracellular matrix on various levels, approaches to emulate cell-extracellular matrix interactions, and biologic delivery strategies to recapitulate a signaling cascade or developmental/would-healing program. The article also provides examples of enhanced cellular/tissue functions and regenerative outcomes, demonstrating the excitement and significance of the biomimetic materials for tissue engineering and regeneration.

Microstructure and properties of nano-fibrous PCL-b-PLLA scaffolds for cartilage tissue engineering

“…The fabrication technologies used for scaffold fabrication in cartilage tissue engineering included electrospinning (Wise et al, 2009), particulate leaching combined with chemical etching Park et al, 2005) and 3-D printing techniques (Yen et al, 2009). L-L TIPS is an easy and effective technique to fabricate 3D nano-fibrous scaffolds (Ma, 2008;Zhang and Ma, 1999). A homogeneous polymer-solvent system would spontaneously undergo a liquid-liquid phase separation when thermodynamically quenched into the unstable zone under the spinodal curve, resulting in a separated polymerrich phase and a polymer-poor phase.…”

“…Recently, intensive studies showed that cells recognized nanometric topologies of fibrous or microporous structure (Laurencin et al, 1999). Such a nanoscale structure, which geometrically mimicked the native state of the extracellular matrix (ECM), could selectively enhance protein adsorption and consequentially enhance cell attachment (Woo et al, 2003), and it therefore received much academic attention in medical applications (Ma, 2008). Zhang and Ma pioneered the preparation of PLLA nano-fibrous scaffolds with a fiber diameter ranging from 50 to 500 nm through thermally induced liquid-liquid phase separation (L-L TIPS) (Ma and Zhang, 1999).…”

Incorporation of PLGA nanoparticles into porous chitosan–gelatin scaffolds: Influence on the physical properties and cell behavior

“…Furthermore, the release kinetics of the target biomolecules can be modulated by changing the composition of the particulate carrier system, the amount of drug encapsulated and the size of the micro/nanoparticles. However, when micro/nanoparticles are incorporated into prefabricated porous scaffolds, they often tend to aggregate, which may not serve the purpose of controlled/spatial delivery of biomolecules (Langer, 1998;Jeong et al, 1997;Ma, 2008). One approach to overcome these limitations is to suspend the biomolecules-loaded micro/nanoparticles into biomaterial solutions during the crosslinking phase of scaffold fabrication.…”

Cell and biomolecule delivery for regenerative medicine

“…The extracellular matrix (ECM) is a model used for inspiration when designing biomimetic scaffolds for tissue engineering [3]. By mimicking the structure and/or surface properties of the naturally occurring ECM, engineers may be able to influence cell growth and tissue formation.…”