25 Apr 2016 |
World innovation news |
Scaffolds for Tissue Engineering Made Cheaper and Scalable
Tissue engineering is a field in biomedical research that aims to enable regeneration of organs or connective tissues from implantation instead of a more traditional transplantation. This means giving the body the ability to regenerate damaged areas by depositing arrays of compatible cells (mainly, stem cells) that boost the repairing and healing process. Furthermore, the new implanted tissue is made out of the patient’s own cells completely avoiding rejection and the inherent complications to organ transplants.
Depositing the new tissue implant back in the donor patient requires a scaffold of bio-compatible material (collagen or polylactic acid, PLA) that works as a structural support layer that eventually will fade away leaving the tissue in its place.
There is extensive research focused in finding efficient and cheaper ways to create scaffolds. So far, one of the most accepted techniques for fabrication is a process called electrospinning. Here, an intense electric field applied to a controlled flux of material pulls tiny fibers that accumulate in the substrate, fusing together and creating a thin, porous layer. There are two main disadvantages to this approach: first, the fibers are too weak, heterogeneous and the pore sizes can be very small for this application. Second, the process is not easily scalable and fabrication of large area scaffolds is time consuming and not very cost-effective.
The team of researchers from the University of North Carolina and North Caroline State University, led by Dr. Elizabeth Loboa wondered if traditional synthetic fabric manufacturing techniques can be applied to the production of efficient scaffolds. They fabricated PLA scaffolds using Melt Blowing, Spunbounding and Carding. All three are commonly used in the production of several types of fabrics nowadays.
Melt blowing (link 1, link 2) is a process where molten plastic comes in and thin strands comes out forming a fine self-bonded web using high speed air flow. Melt blown synthetic fabrics have an extensive market in filtration like surgical masks and medical fabrics like disposable gowns.
Spunbonding, is close to melt blowing with the difference that the web is created using solid fibers rather than molten ones. These fabrics are found mostly in the backing of carpets for the automotive industry as well as several construction applications due to their chemical stability and strength.
Carding fabrics are commonly found in the fabrication of tweed fabrics and involves using rolls with needles to create strands of “combed” fibers that will be sewn together afterwards.
Among their findings, the team reported a lower cost of production of scaffolds of the same size. Indeed, the cost of a scaffold produced by electrospinning ranges between $2-5, whereas scaffolds produced using the more traditional approaches costed $1-2, $0.30-3 and $0.10-3 for meltblown, spunbound and carded respectively.
Furthermore, thanks to the fabrication stability found in these three techniques, the PLA fibers are uniform and the pore size is more appropriate to work with human adipose derived stem cells (hASCs) and cultured in complete growth medium (CGM). These scaffolds performed equal or better showing successful cell viability, proliferation and differentiation, which is the major goal prior to the implantation procedure.
To further continue this research, now the team looks to implant these scaffold + tissue structures into animals to test their effectiveness in triggering regeneration process. With techniques that are readily scalable, this discovery opens the door to a cost-effective tissue therapy and large area fabrication of implants.
This study can be found in the following sources, source 1 and source 2.
Luis Felipe Gerlein Reyes
Luis Felipe Gerlein R. is a Ph.D. candidate at ÉTS. His research interests include nanofabrication and characterization of optoelectronic devices based on lead chalcogenides, carbon-based nanostructures and perovskite materials.
Program : Electrical Engineering