434770 Mimicking Cell-Cell Interactions in 3D with Proteolipobeads

Tuesday, November 10, 2015: 4:45 PM
251A (Salt Palace Convention Center)
Eric Fried1, M. Lane Gilchrist1 and Steve Nicoll2, (1)Chemical Engineering, City College of New York, New York, NY, (2)Biomedical Engineering, City College of New York, New York, NY


The central focus of tissue engineering is the re-creation of complexities found in cells and cellular microenvironments. We have developed biomembrane-microsphere constructs that are capable of presenting ligands/bound factors to stem cells, mimicking in vivocell-cell interactions that occur in the stem cell niche. Our platform, termed proteolipobeads (PLBs), features laterally-mobile proteins and peptides integrated within a synthetic biomembrane. While well established in 2D systems, biomimetic cell-cell communication involving model cell membranes has not taken hold in 3D stem cell culture systems.

We present results on three aspects of this study: 1) the fabrication and characterization of PLBs displaying surface-functional molecules, 2) the construction and characterization of hydrogel/PLB hybrid scaffolds, and 3) preliminary experiments of human mesenchymal stem cells (hMSCs) microencapsulated into matrix/PLB hybrid scaffolds. Special attention was given to the viability of hMSCs and the frequency and extent of hMSC-PLB interactions within these hybrid scaffolds. We will also describe the development of peptide-cadherin fusion protein conjugates that promote cellular interactions and peptide-based biomembrane anchoring to the microsphere surface. Finally, we will discuss recent progress in creating a fully biocompatible platform featuring biodegradable PLBs.

Confocal microscopy studies were conducted to assess the diffusivity of laterally mobile PLB constituents (via FRAP) and to visualize N-cadherin-mediated PLB interactions with hMSCs in situ. Immunohistochemical staining was used to detect N-Cadherin within the hybrid matrices relative to counterstained supported lipid bilayers. This work constitutes a new, physiologically relevant method for displaying mobile membrane proteins and signaling molecules to live cells within 3D matrices.

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See more of this Session: Biomimetic Materials
See more of this Group/Topical: Materials Engineering and Sciences Division