Friday, 20 October 2017 14:21

Understanding cell growth in synthetic polymers

MPC-CMSE Summer Scholar Amy Duggal tests how cells respond to a new biopolymer.

MIT Professor Paula T. Hammond’s lab is developing nanomaterials for a wide range of applications ranging from treatment of diseases to regenerative medicine. Hammond is head of the Department of Chemical Engineering and David H. Koch (1962) Professor in Engineering. Materials Processing Center – Center for Materials Science and Engineering [MPC-CMSE] Summer Scholar Amrita [Amy] Duggal assessed the utility of a synthetic proteoglycan developed in the Hammond Lab for biomaterial applications.

Duggal, a biochemistry major from California State University, Channel Islands, says, “My research is based on looking at cellular response as well as cell behavior in presence of the biopolymer.”

MIT Chemistry PhD student Wade Wang supervised Duggal’s work in the lab. “Amy's project is really foundational in looking at the interaction of this new polymer that we've developed in the lab. So we want to characterize exactly how this polymer interacts with cells so we can develop new biomaterials based on this polymer,” Wang explains. Wang previously synthesized graft copolymers of poly(γ-propargyl-L-glutamate) [PPLG], a synthetic polypeptide, and hyaluronic acid [HA], an ubiquitous polysaccharide in the body. Cellular interactions with HA are dependent on it size, so by changing the structure of the graft copolymer containing HA the cellular response can be controlled.

Duggal utilized the scratch test, a cell migration assay commonly used in cancer and wound healing studies, to carry out her project. “Cell migration is an important phenomenon when you're trying to study development, maintenance, as well as metastasis and invasion, in cancer cell lines,” Duggal explains.

“Once these cells are scratched…they are treated with the biopolymer treatment,” Duggal notes. The rate and extent of migration, which contribute to “healing” of the scratch, can be promoted or inhibited by PPLG-HA biopolymer treatment. This response is affected by the architecture and molecular weight the biopolymers, which Duggal is interested in optimizing for wound healing applications.

Summer Scholar Amy Duggal 9014 DP Web
MPC-CMSE Summer Scholar Amrita [Amy] Duggal uses a microscope to visualize cell migration in the Hammond Lab. Duggal’s summer internship project studied the effect of a synthetic biopolymer developed in the Hammond Lab on cells that are intentionally damaged to mimic wounds and cancer in people. Photo, Denis Paiste, Materials Processing Center.

“Once the biopolymeric treatment is added to the cell culture, we can visualize whether the biopolymer treatment inhibits or promotes wound healing in these cells,” Duggal says.

During a visit to the lab, Duggal shows images of the cells she recently scratched and treated with biopolymer to study cell migration. “We use the microscope to visualize and understand cell migration,” Duggal notes. The extent of healing and persistence of damage are apparent from the images. After the damaged cells are treated with the biopolymer and incubated for 8 to 12 hours, visual confirmation is apparent that the gap in those cells has closed significantly. “There seems to be cell migration and wound healing to a certain extent,” she says.

In addition to imaging, Duggal further assessed cellular response to the biopolymer with chemical assays for cellular proliferation. This is important because wound healing is a combination of many cellular behaviors, including migration and proliferation. In particular, Duggal uses BRDU [BromodeoxyUridine], a synthetic nucleoside, as a marker to quantify cell growth.

Duggal’s internship is supported in part by NSF’s Materials Research Science and Engineering Centers program [grant DMR-14-19807]. Participants in the Research Experience for Undergraduates, co-sponsored by the Materials Processing Center and the Center for Materials Science and Engineering, presented their results at a poster session during the last week of the program. The program ran from June 15, 2017, to August 5, 2017, on the MIT campus in Cambridge, Mass.

 

– Denis Paiste, Materials Processing Center
September 25, 2017

 

Summer Scholar Amy Duggal 9187 DP Web
MPC-CMSE Summer Scholar Amrita [Amy] Duggal presents her research on the effect of a synthetic biopolymer developed in the Hammond Lab on cells that are intentionally damaged to mimic wounds and cancer in people during the annual MPC-CMSE Summer Scholars Poster Session on Aug. 3, 2017. Photo, Denis Paiste, Materials Processing Center.