PC12 Cell Activity on Poly (Ethylene Glycol) Hydrogels

PC12 Cell Activity on Poly (Ethylene Glycol) Hydrogels

Student(s):

Sonja Sokic

 

Advisor(s):

Dr. Rebecca K. Willits

When nerve damage occurs, minimal recovery by the body results and surgical intervention may be needed. Conduit tubes are of interest to replace tissue taken from the patient to be harvested in the damaged site in the body. The current use of conduit tubes has been collagen conduit tubes. Collagen may cause an immunogenic response and thus a synthetic material would be more suitable. Patterning via photolithography has been investigated in our laboratory as a mechanism to guide neurite growth. The material of choice has been poly (ethylene glycol) (PEG) because of its biocompatibility, inertness and promise when chemically modified. Collagen was used to enhance neurite growth by generation of fouling and anti-fouling regions. Initial studies looked at PC12 cell behavior on 5 wt% PEG gels with varying collagen concentrations. The highest collagen concentration studied (3 mg/mL) resulted in highest neurite expression and therefore was used for the patterning experiments. PC12 cells were seeded atop patterned 5 wt% PEG-3 mg/mL collagen gels, and within gels of varying confinements in PEG/PEG-collagen. A study also looked at UV light exposure effects on PC12 cells. PC12 cell aggregates were analyzed via shape indices using ImageJ. The results of this study indicate no differences in neurite expression between 2D patterned and unpatterned gels. While the PC12 cells failed to express in 3D patterned gels, the UV light study indicated cell damage due to simple UV exposure. A correlation was found between the shapes of aggregates to the adhesiveness of the substrates. Generally, the average projected aggregate area increased in the presence of collagen. Further study is needed to investigate UV effects in 3D systems.