Fibroblast Morphology on Dynamic Softening of Hydrogels
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Despite cellular environments having dynamic characteristics, many laboratories utilized static polyacrylamide hydrogels to study the ECM–cell relationship. To attain a more in vivo like environment, we have developed a dynamic, DNA-crosslinked hydrogel (DNA gel). Through the controlled delivery of DNA, we can temporally decrease or increase gel stiffness while expanding or contracting the gel, respectively. These dual mechanical changes make DNA gels a cell–ECM model for studying dynamic mechano-regulated processes, such as wound healing. Here, we characterized DNA gels on a mechanical and cellular level. In contrast to our previous publication, in which we examined the increasing stiffness effects on fibroblast morphology, we examined the effects of decreased matrix stiffness on fibroblast morphology. In addition, we quantified the bulk and/or local stress and strain properties of dynamic gels. Gels generated about 0.5 Pa stress and about 6–11% strain upon softening to generate larger and more circular fibroblasts. These results complemented our previous study, where dynamic gels contracted upon stiffening to generate smaller and longer fibroblasts. In conclusion, we developed a biomaterial that increases and decreases in stiffness while contracting and expanding, respectively. We found that the dynamic deformation directionality of the matrix determined the fibroblast morphology and possibly influences function.
KeywordsStress Strain ECM Compliance Stiffness DNA gel Wound healing
This work was supported by NJSCR #08-3080-SCR-E-0. K.T. supported by Rutgers RiSE summer program, Rutgers REU-CB (NSF EEC-0851831), and The College of St. Scholastica Ronald E. McNair Postbaccalaureate Achievement Program. We would like to thank Christopher Liu for analysis of cell density and editing of this manuscript. We would like to thank Dr. David I. Shreiber for the GFP fibroblasts. Lastly, we would like to thank Namrata Kulkarni and Vikas Shah for editing this manuscript.
Conflict of interest
Authors have no conflict of interest.
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