Neural diversity is achieved in part by the activity of morphogen gradients that operate during early embryonic development. In a concentration dependent manner, morphogens direct distinct cell identities in early central nervous system progenitors, and sonic hedgehog (Shh) is one such powerful morphogen. Shh is secreted from the notochord and floor plate structures and drives the dorso-ventral (DV) patterning of the developing neural tube. DV patterning is revealed by a restricted expression of homeodomain transcription factors in distinct neuronal progenitor domains. Despite our understanding of neural progenitor diversification by Shh, it is difficult to isolate, study, and follow individual neural progenitor cells during patterning in vivo. For this reason, a simplified in vitro model system would be beneficial to refine our understanding of Shh mediated DV patterning in the developing CNS.
Towards the design of in vitro culture systems, hydrogel-based biomaterials afford unique opportunities for spatiotemporal control over the release of signaling molecules. A recent publication from the Anseth group introduced a microsphere system capable of spatiotemporal control of protein delivery via light-mediated degradation. My initial efforts have focused on incorporating Shh into the photodegradable microspheres to offer spatial delivery of the protein on demand.
D.R. Kryscio, M.Q.Fleming, and N.A. Peppas, “Protein Conformational Studies for Macromolecularly Imprinted Polymers,” Macromol. Biosci., (2012), DOI: 10.1002/mabi.201200068
D.R. Kryscio, M.Q.Fleming, and N.A. Peppas, “Conformational studies of common protein templates in macromolecularly imprinted polymers,” Biomed. Microdev., 14, 679–687 (2012)
B. Zhang, J. Feng, M.Q. Fleming, and S.K. Mallapragada, “Injectable self-assembled block copolymers for sustained gene and drug co-delivery: in vitro study with synthetic gels to mimic tumor matrix,” Int J Pharm, 427(1), 88-96 (2012)