Aligned and alit
Fluorescent
labeling shows extra cellular matrix (green) aligned with the directions
specified by
shaped tissue culture molds. Image: Jacquelyn Schell/Brown University
(November 9, 2015) Extracellular
matrix is the material that gives tissues their strength and stretch. It’s been
hard to make well in the lab, but a Brown University team reports new success.
The key was creating a culture environment that guided cells to make ECM
themselves.
Imitation may be the sincerest form of flattery but the best
way to make something is often to co-opt the original process and make it work
for you. In a sense, that’s how scientists at Brown University accomplished a
new advance in tissue engineering.
In the journal Biomaterials, the team reports culturing
cells to make extracellular matrix (ECM) of two types and five different
alignments with the strength found in natural tissue and without using any
artificial chemicals that could make it incompatible to implant.
ECM is the fibrous material between cells in tissues like
skin, cartilage, or tendon that gives them their strength, stretchiness,
squishiness, and other mechanical properties. To help patients heal wounds and
injuries, engineers and physicians have strived to make ECM in the lab that’s
aligned as well as it is when cells make it in the body. So far, though,
they’ve struggled to recreate ECM. Using artificial materials provides
strength, but those don’t interact well with the body. Attempts to extract and
build upon natural ECM have yielded material that’s too weak to reimplant.
The Brown team tried a different approach to making both
collagen, which is strong, and elastin, which is stretchy, with different
alignments of their fibers. They cultured ECM-making cells in specially
designed molds that promoted the cells to make their own natural but precisely
guided ECM.