Researcher(s)
- Alec Schwendinger, Chemical Engineering, University of Minnesota - Twin Cities
Faculty Mentor(s)
- April Kloxin, Chemical and biomolecular engineering, University of Delaware
Abstract
Abstract:
Cell-based therapies for various cancers have shown higher effectiveness than other common cancer therapies, such as chemotherapies. The current method uses a poly(ethylene glycol) (PEG) hydrogel to aid in cellular proliferation for these therapies. However, these therapies produce T-cells with lowered functionality due to PEG’s elastic character. This elastic character is distinct from the T-cells native environment, which is known to have a viscoelastic character. It was hypothesized that adding assembling peptides to the PEG hydrogel would allow for the hydrogel’s mechanical properties to better resemble those of the native environment. Two quantities which were monitored and compared to native lymph tissue’s mechanical properties were its relaxation time and the Young’s modulus of the system. Relaxation time was obtained from stress relaxation tests and indicated the viscoelastic character of the gel while Young’s modulus indicated bulk mechanical properties of the gel.
Two materials, collagen mimetic peptides (CMPs) and bundlemers, were incorporated into the PEG gel to test this hypothesis. For relaxation time, lymph tissues experience a relaxation time of anywhere from 100-1000s. The control produced a Young’s modulus of 18 ± 3 kPa and lymph tissues have a Young’s modulus anywhere from 4-30 kPa. A 5 mM inclusion of the CMP’s produced a relaxation time of ~200 s and Young’s modulus of 47 ± 8 kPa. A 0.01 mM inclusion of the bundlemers resulted in a relaxation time of ~800 s and Young’s modulus of 61 ± 4 kPa. Both relaxation times indicate viscoelasticity being present, but both Young’s moduli were too high for the desired range. Further research will be done concerning changing the concentration of CMP and bundlemer to tune this property. Eventually, these results will be used in studying cellular responses from T-cells themselves to determine the efficacy of the hydrogel for cell-based therapies.