Engineering extracellular matrix through nanotechnology

Abstract

The goal of tissue engineering is the creation of a living device that can restore, maintain or improve tissue function. Behind this goal is a new idea that has emerged from twentieth century medicine, science and engineering. It is preceded by centuries of human repair and replacement with non-living materials adapted to restore function and cosmetic appearance to patients whose tissues have been destroyed by disease, trauma or congenital abnormality. The nineteenth century advanced replacement and repair strategies based on moving living structures from a site of normal tissue into a site of defects created by the same processes. Donor skin into burn wounds, tendon transfers, intestinal replacements into the urinary tract, toes to replace fingers are all examples. The most radical application is that of vital organ transplantation in which a vital part such as heart, lung or liver is removed from one donor, preserved for transfer and implanted into a patient dying of end-stage organ failure. Tissue engineering and regenerative medicine have advanced a general strategy combining the cellular elements of living tissue with sophisticated biomaterials to produce living structures of sufficient size and function to improve patients' lives. Multiple strategies have evolved and the application of nanotechnology can only improve the field. In our era, by necessity, any medical advance must be successfully commercialized to allow widespread application to help the greatest number of patients. It follows that business models and regulatory agencies must adapt and change to enable these new technologies to emerge. This brief review will discuss the science of nanotechnology and how it has been applied to this evolving field. We will then briefly summarize the history of commercialization of tissue engineering and suggest that nanotechnology may be of use in breeching the barriers to commercialization although its primary mission is to improve the technology by solving some remaining and vexing problems in its science and engineering aspects.

Liposomes in tissue engineering and regenerative medicine

“…For instance, bone morphogenetic protein 2 (BMP-2) is added to induce the osteogenic differentiation, whereas transforming growth factor b (TGF-b) is used to promote the chondrogenic differentiation. An adequate combination of signalling molecules should be provided by controlled release systems in order to promote the desired regenerative outcome [112,[157][158][159]. Therefore, liposomes can be used as carriers for the spatio-temporal controlled delivery of GFs, improving stem cell proliferation and differentiation in vitro [160,161].…”

Microporous Dermal-Like Electrospun Scaffolds Promote Accelerated Skin Regeneration

“…[8][9][10] One of the main limitations of electrospun scaffolds is that the pores created by the nanofibrous mesh have small diameters which impede cell infiltration, hindering scaffold remodeling and wound healing. [11][12][13] A number of reports have highlighted the importance of porosity within skinmimetic materials in facilitating fibroblast, endothelial, and stem cell infiltration; nutrient transport for better graft survival; and neovascularization. [14][15][16] On the other hand, if pores are too large, cells may have a difficult time filling the void with ECM.…”

Nanofibers and their biomedical use

“…The underlying rationale is that different injuries or pathological conditions cause a change in the ECM in the body and cells have to restore it during the regeneration process. Unfortunately, physiological ECM formation is often insufficient or even disrupted and it is therefore reasonable to expect that the application of an ECM analogue will enhance natural tissue repair, since the tissue will adopt the applied scaffold as its own ECM (5,15).…”

“…It is much more than just a physical support for the cells. ECM also represents a substrate for cell adhesion via specific ligands, provides and directs cell migration and regulates their growth and functions through a variety of bioactive factors (14,15).…”