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Hydrogel microparticles for biomedical applications

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Abstract

Hydrogel microparticles (HMPs) are promising for biomedical applications, ranging from the therapeutic delivery of cells and drugs to the production of scaffolds for tissue repair and bioinks for 3D printing. Biologics (cells and drugs) can be encapsulated into HMPs of predefined shapes and sizes using a variety of fabrication techniques (batch emulsion, microfluidics, lithography, electrohydrodynamic spraying and mechanical fragmentation). HMPs can be formulated in suspensions to deliver therapeutics, as aggregates of particles (granular hydrogels) to form microporous scaffolds that promote cell infiltration or embedded within a bulk hydrogel to obtain multiscale behaviours. HMP suspensions and granular hydrogels can be injected for minimally invasive delivery of biologics, and they exhibit modular properties when comprised of mixtures of distinct HMP populations. In this Review, we discuss the techniques that are available for fabricating HMPs, as well as the multiscale behaviours of HMP systems and their functional properties, highlighting their advantages over traditional bulk hydrogels. Furthermore, we discuss applications of HMPs in the fields of cell delivery, drug delivery, scaffold design and biofabrication.

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Fig. 1: Categories of HMPs.
Fig. 2: Fabrication of HMPs.
Fig. 3: Microfluidic and lithographic templating of compartmentalized HMPs.
Fig. 4: Structure and properties of granular hydrogels.
Fig. 5: Hydrogel microparticle delivery to various tissues in the body.
Fig. 6: Drug release from HMPs.
Fig. 7: Design considerations for building scaffolds from HMPs.
Fig. 8: HMPs in biofabrication.

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Acknowledgements

J.A.B. acknowledges funding through the National Science Foundation through the PENN MRSEC (DMR-1720530) and STC Program (CMMI: 15-48571). T.S. acknowledges funding from the National Institutes of Health (R01NS094599) and Duke Biomedical Engineering. The authors would like to thank their laboratories for the helpful input and suggestions on the manuscript.

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Author notes

  1. These authors contributed equally: Andrew C. Daly, Lindsay Riley

Authors and Affiliations

  1. Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA

    Andrew C. Daly & Jason A. Burdick

  2. Department of Biomedical Engineering, Duke University, Durham, NC, USA

    Lindsay Riley & Tatiana Segura

  3. Departments of Dermatology and Neurology, Duke University, Durham, NC, USA

    Tatiana Segura

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All authors contributed equally to the preparation of this manuscript.

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Daly, A.C., Riley, L., Segura, T. et al. Hydrogel microparticles for biomedical applications. Nat Rev Mater 5, 20–43 (2020). https://doi.org/10.1038/s41578-019-0148-6

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