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Discovery by U of T researchers could create retinas from “Jello”

August 30, 2011

Team led by Professor Molly Shoichet identifies new method for creating hydrogels to aid tissue engineering

TORONTO, ON — Researchers at the Uni­ver­si­ty of Toron­to have devel­oped a new method for cre­at­ing 3D hydro­gel scaf­folds that will aid in the devel­op­ment of new tis­sue and organs grown in a lab.

The dis­cov­ery is out­lined in the lat­est issue of Nature Mate­ri­als.

Hydro­gels, a “jel­lo” like sub­stance, are high­ly flex­i­ble and absorbent net­works of poly­mer strings that are fre­quent­ly used in tis­sue engi­neer­ing to act as a scaf­fold to aid cel­lu­lar growth and devel­op­ment.

The paper demon­strates for the first time that it is pos­si­ble to immo­bi­lize dif­fer­ent pro­teins simul­ta­ne­ous­ly using a hydro­gel. This is crit­i­cal for con­trol­ling the deter­mi­na­tion of stem cells, which are used to engi­neer new tis­sue or organs.

“We know that pro­teins are very impor­tant to define cell func­tion and cell fate. So work­ing with stem cells derived from the brain or reti­na we have demon­strat­ed we can spa­tial­ly immo­bi­lize pro­teins that will influ­ence their dif­fer­en­ti­a­tion in a three-dimen­sion­al envi­ron­ment,” explains Pro­fes­sor Mol­ly Shoichet of the Depart­ment of Chem­i­cal Engi­neer­ing & Applied Chem­istry, the Insti­tute for Bio­ma­te­ri­als & Bio­med­ical Engi­neer­ing and the Depart­ment of Chem­istry.

Immo­bi­liz­ing pro­teins main­tains their bioac­tiv­i­ty, which had pre­vi­ous­ly been dif­fi­cult to ensure. It is also impor­tant to main­tain spa­cial con­trol as the tis­sue and organs are three-dimen­sion­al. There­fore, being able to con­trol cell fate and under­stand­ing how cells inter­act across three dimen­sions is crit­i­cal.

“If we think about the reti­na, the reti­na is divid­ed into sev­en lay­ers. And if you start with a reti­nal stem cell, it has the poten­tial to become all of those dif­fer­ent cell types. So what we are doing is immo­bi­liz­ing a pro­tein which will cause their dif­fer­en­ti­a­tion into pho­tore­cep­tors or bipo­lar neu­rons or oth­er cell types that would make up those sev­en dif­fer­ent cell types,” says Pro­fes­sor Shoichet.

The end result is a new hydro­gel that can guide stem cell devel­op­ment in three-dimen­sions.

Pro­fes­sor Shoichet iden­ti­fies two long-term out­comes from this dis­cov­ery.

“We could use… it as a plat­form tech­nol­o­gy to look at the inter­ac­tion of dif­fer­ent cells and build tis­sues and organ,” Pro­fes­sor Shoichet states, while also not­ing that it could help lead to a more fun­da­men­tal under­stand­ing of cel­lu­lar inter­ac­tion. “By grow­ing cells in a 3D envi­ron­ment, sim­i­lar to how they grow in our body, we can devel­op a bet­ter under­stand­ing of cell process­es and inter­ac­tions.”

The research was led by Pro­fes­sor Shoichet and was con­duct­ed by Ryan G. Wylie,  Shoeb Ahsan, Yukie Aiza­wa, Karen L. Maxwell and Cin­di M. Mor­shead.

Mak­ing a Reti­na from Jel­lo — Pro­fes­sor Mol­ly Shoichet from U of T Engi­neer­ing on Vimeo.


For more infor­ma­tion, please con­tact:

Liam Mitchell
Com­mu­ni­ca­tions & Media Rela­tions Strate­gist
Fac­ul­ty of Applied Sci­ence & Engi­neer­ing