Smart Materials for Manipulating Cell/Surface and Cell/Cell Interactions

PIs: Canavan,1 Fulghum,1 Parker,2 Mooney,2 Weitz2

Students: Candelaria,1 Cooperstein,1 Liu,1 Wilde1

1University of New Mexico; 2Harvard University

Poly(N-isopropyl acrylamide) (pNIPAM) undergoes a sharp property change in response to a moderate temperature drop. Above its lower critical solution temperature (LCST, ~32 °C), biological cells adhere and proliferate; below its LCST, cell sheets detach intact--and can be used for tissue engineering.

During Year 2 of our funding, we constructed a tissue culture laboratory for the culture of mammalian cells (top). Using our rf plasma reactor (built in Year 1), we fabricated thermoresponsive films for mammalian cells, and found that the materials retain their “smart” behavior. We optimized the temperature and media used to achieve popoff (middle). The results of this research were included in our first research article submitted.

As a response to the wide interest generated from our Outreach Program, we submitted an article to Chem. Eng. Ed., which was accepted for publication this summer. This article outlines our highly popular “Finger Kit” demonstrations in the 5th grade (bottom), including the educational benchmarks it addresses, and the materials needed for readers to adopt it in their own programs.

Reed, et al., “The Effects of Cell Culture Parameters on Cell Release Kinetics from pNIPAM,” submitted.Canavan, et al., “ ‘Finger Kits’: An Interactive Demonstration of Biomaterials and Engineering for Elementary School Students,” accepted. Lucero, et al., “Plasma Polymerized Biocompatible ‘Smart’ Surfaces,” presented at AAAS/SWARM, April 20, 2008, honorable mention for best student poster.

Gabriel P. Lopez, University of New Mexico, DMR 0611616   

Seed Project 1: : Influence of Active Materials on Cellular Function

PIs: Dirk,1 Mooney,2 Parker2

Students: de la Iglesia,1 Hellebust,1 Martinez1

1University of New Mexico; 2Harvard University

The general approach of tissue engineering is to use biodegradable materials that act as a temporary support for cells while they form their desired extracellular matrix (ECM) that can then be implanted into the body to replace damaged tissue. Much of the work in this field has focused on the use of inert materials, i.e., materials that support cell adhesion and function but do not interact with the cells to induce a specific response. Recent studies suggest, however, that properties inherent to the support material such as surface chemistry and stiffness of the support material may influence cellular function.

During Year 1, we remodeled existing lab space to create a polymer synthesis laboratory and a mammalian cells tissue culture laboratory. While waiting for our laboratory space, we focused on the fabrication of chemically patterned surfaces that posses nano-scale cell adhesive patches surrounded by a non-cell adhesive surface. These surfaces were characterized using AFM (top) and visualized with SEM. Cells were seeded on these surfaces and shown to interact with the adhesive patches (middle). A manuscript of these results is currently in progress. Further studies will explore cell attachment, spreading, and ECM production on surfaces with varied distances between patches. Additionally, we will begin to examine the effects of material stiffness.

As Outreach Director this year, I headed the Biomaterials Outreach Program. In addition to the already successful 5th grade and High School programs, we developed a new 8 th grade classroom module, “Polymers in Medicine,” in collaboration with Kathryn Hollar at Harvard University. Throughout fall 2007, we visited 8 classes at Washington Middle School (Bottom). Our new efforts were featured in articles in both Albuquerque newspapers and two local newscasts. We also expanded our outreach efforts to elementary/mid-school teachers of Albuquerque as well as the Navajo Nation with workshops where we demonstrated our 8th and 5th grade programs, respectively.

Gabriel P. Lopez, University of New Mexico, DMR 0611616