Abstract
Engineered microscale hydrogels have emerged as promising therapeutic approaches for the treatment of various diseases. These microgels find wide application in the biomedical field because of the ease of injectability, controlled release of therapeutics, flexible means of synthesis, associated tunability, and can be engineered as stimuli-responsive. While bulk hydrogels of several length-scale dimensions have been used for over two decades in drug delivery applications, their use as microscale carriers of drug and cell-based therapies is relatively new. Herein, we critically summarize the fundamentals of hydrogels based on their equilibrium and dynamics of their molecular structure, as well as solute diffusion as it relates to drug delivery. In addition, examples of common microgel synthesis techniques are provided. The ability to tune microscale hydrogels to obtain controlled release of therapeutics is discussed, along with microgel considerations for cell encapsulation as it relates to the development of cell-based therapies. We conclude with an outlook on the use of microgels for cell sequencing, and the convergence of the use of microscale hydrogels for drug delivery, cell therapy, and cell sequencing based systems.
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Acknowledgements
This work is submitted in honor of Professor Mauro Ferrari’s 60th birthday. Mauro has been an inspirational force in the fields of nanotechnology and bionanotechnology. His writings have been extremely important in defining these fields, and the senior authors who have known him and worked with him appreciate all the contributions he has made to their research, directly and indirectly.
We acknowledge financial support from the National Institutes of Health (R01-AI132738-01A1 and 5R33CA212968-02 awarded to AS; R01-EB022025 awarded to NAP), the National Science Foundation CAREER award (DMR-1554275 awarded to AS), Department of Defense CDMRP and Cancer Career Development Award (W81XWH-17-1-0215 awarded to AS). In addition, NAP acknowledges support from the Cockrell Family Chair Foundation and the office of the Dean of the Cockrell School of Engineering at the University of Texas at Austin for the Institute for Biomaterials, Drug Delivery, and Regenerative Medicine. We acknowledge financial support from the National Science Foundation Graduate Research Fellowship Program (DGE-1610403 awarded to MEW; DGE-1650441 awarded to RES). Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the funding agencies.
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Wechsler, M.E., Stephenson, R.E., Murphy, A.C. et al. Engineered microscale hydrogels for drug delivery, cell therapy, and sequencing. Biomed Microdevices 21, 31 (2019). https://doi.org/10.1007/s10544-019-0358-0
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DOI: https://doi.org/10.1007/s10544-019-0358-0