Combinatorial hydrogel library enables identification of materials that mitigate the foreign body response in primates

A Corrigendum to this article was published on 09 June 2016

This article has been updated


The foreign body response is an immune-mediated reaction that can lead to the failure of implanted medical devices and discomfort for the recipient1,2,3,4,5,6. There is a critical need for biomaterials that overcome this key challenge in the development of medical devices. Here we use a combinatorial approach for covalent chemical modification to generate a large library of variants of one of the most widely used hydrogel biomaterials, alginate. We evaluated the materials in vivo and identified three triazole-containing analogs that substantially reduce foreign body reactions in both rodents and, for at least 6 months, in non-human primates. The distribution of the triazole modification creates a unique hydrogel surface that inhibits recognition by macrophages and fibrous deposition. In addition to the utility of the compounds reported here, our approach may enable the discovery of other materials that mitigate the foreign body response.

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Figure 1: Combinatorially modified hydrogels with reduced subcutaneous inflammation and fibrosis.
Figure 2: Three lead hydrogels show reduced fibrosis intraperitoneally in C57BL/6J mice.
Figure 3: Lead hydrogels show low immune cell recruitment in vivo with covalently modified surfaces.
Figure 4: Lead hydrogels mitigate the foreign body response in non-human primates.

Change history

  • 18 April 2016

    In the version of this article initially published, one author, Adam C. Graham, his affiliation, and his contribution were omitted. In addition, two acknowledgments, to W. Salmon and J. Wyckoff, were omitted. The errors have been corrected in the HTML and PDF versions of the article.


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This work was supported jointly by the JDRF and Leona M. and the Harry B. Helmsley Charitable Trust (grant 3-SRA-2014-285-M-R), National Institutes of Health (NIH grants EB000244, EB000351, DE013023 and CA151884), NIH NIBIB (P41EB015871-27), MIT SkolTech initiative (J.W.K.), JDRF and the Department of Defense/Congressionally Directed Medical Research Programs (DOD/CDMRP postdoctoral fellowships 3-2013-178 and W81XWH-13-1-0215 for O.V.) and through a generous gift from the Tayebati Family Foundation. G.C.W. is supported by National Institutes of Health (NIH grants R01DK093909 and P30DK036836, the Joslin Diabetes Research Center and its Advanced Microscopy Core), as well as the Diabetes Research and Wellness Foundation. J.O. is supported by the National Institutes of Health (NIH/NIDDK) R01DK091526 and the Chicago Diabetes Project. This work was also supported in part by the Koch Institute Support (core) grant P30-CA14051 from the National Cancer Institute. We also thank the Koch Institute Swanson Biotechnology Center for technical support, specifically Tang Histology Facility, Microscopy, Flow Cytometry, Nanotechnology Materials, and Applied Therapeutics and Whole Animal Imaging. The authors would like to acknowledge the use of resources at the Harvard University Center for Nanoscale Systems and W.M. Keck Biological Imaging Facility (Whitehead Institute). The authors would also like to thank W. Salmon and J. Wyckoff for their assistance.

Author information




A.J.V., O.V., J.C.D., M.M., K.B., J.L., A.R.B., E.L., K.O., P.F., J.W.K., J.H.-L., M.A.B., A.C., S.S., K.T., S.J., S.A.-D., N.D., R.T., T.V., M.C., J.C., K.S., M.Q. and J.M. designed and performed experiments, and analyzed data. H.H.T. assisted with data processing and data presentation. A.C.G. assisted with SEM imaging. S.L. assisted with histology. D.M.H., D.L.G., J.O. and G.C.W. provided conceptual advice and technical support. A.J.V. and D.G.A. wrote the paper. R.L. and D.G.A. supervised the study. All authors discussed the results and commented on the manuscript.

Corresponding author

Correspondence to Daniel G Anderson.

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Competing interests

A.J.V., O.V., J.C.D., M.M., K.B., R.L. and D.G.A. declare financial interest in patents filed by MIT on the material and hydrogel capsule technology.

Integrated supplementary information

Supplementary Figure 1 Reagents used for polymer modification.

Amines, alcohols, azides, and alkynes used for the chemical modification of alginate.

Supplementary Figure 2 Additional data for lead materials tested in C57BL/6J mice.

(a) Evaluation of enzyme activity of cathespins B and L in the absence and presence of 20 mM barium chloride. No reduction in enzymatic activity is observed (n = 6, mean values ± SD). (b) Representative hematoxylin and eosin (HE) stained subcutaneous 28 day histology of the top ten alginate analogue microcapsules and control alginate microcapsules (SLG20, V/S) that were implanted in Figure 2, n = 3 mice per group. Abnormal microcapsule morphology is caused by histological processing (dehydration) of the tissue. Scale bar = 400 µm. (c) PCA functional group analysis of the entire modified alginate library, with top performing materials indicated. Triazole-containing modifications are enriched for favorable in vivo performance. (d) Western-blot images used for SMA quantification in Figure 2c. Protein was extracted from retrieved microcapsules (n = 5 mice per group) of the top three alginate analogues and controls after 14 days IP in C57BL/6J mice. (e) Cellular viability of RAW 264.7 cells exposed to formulated lead microcapsules (n = 12, mean values ± SD). (f) Cytokine panel analysis of protein extracted from retrieved microcapsules (n = 5 mice per group) in Figure 2a. Scale shows average fold signal above background.

Supplementary Figure 3 Nanostring gene expression analysis.

Gene expression analysis of seventy-nine known inflammatory factors and immune cell markers from retrieved IP fluid, fat pad, and microcapsules 14 days post-implantation in C57BL/6J mice. Gene expression from IP and fat pad was normalized to mock implant controls, while gene expression from microcapsule-associated tissue was normalized to the SLG20 sample.

Supplementary Figure 4 Determination of potential contaminants in controls and lead materials.

(a) Determination of potential contaminant levels of alginate microcapsules prior to implantation. Endotoxin and glucan levels were measured and reported by Charles River Laboratories. The standard curves used for quantification of (b) flagellin and (c) LTA levels are also shown.

Supplementary Figure 5 Additional FACS data.

FACS analysis of (a) macrophages and (b) neutrophils isolated from retrieved 300 µm microcapsules after 14 days IP in C57BL/6J mice, n = 5 mice per group. One-way ANOVA with Bonferroni correction was utilized to allow for statistical comparison of multiple means, # = p < 0.05, ** = p < 0.001, *** = p < 0.0001, ns = not signficant. The data express the number of cells as a percentage of total cells measured. (c) Representative dot plots of FACS analysis for macrophages and neutrophils presented in (a) and (b).

Supplementary Figure 6 Additional confocal raman and cryo-SEM imaging of lead materials.

(a) Confocal raman cross-section mapping of 300 µm Z1-Y15 microcapsules. The raman peak at 857 cm-1 (shown in red) is indicative of the thiomorpholine dioxide end group of Z1-Y15, and peak intensity is enriched at the surface of the microcapsules than at the core. The peak at 884 cm-1 is mapped in green as a reference to the alginate backbone structure. (b) Confocal raman cross-section mapping of 300 µm Z1-Y19 microcapsules. The raman peak at 1563 cm-1 (shown in red) is indicative of the aniline end group of Z1-Y19, and peak intensity appears more uniform at both the surface of the microcapsules and at the core. The peak at 884 cm-1 is mapped in green as a reference to the alginate backbone structure. (c) Representative freeze-fracture cryo-SEM images of the core (scale bar = 10 µm) and fractured surface (scale bar = 10 µm) of 300 µm SLG20, V/S, Z2-Y12, Z1-Y15, and Z1-Y19 microcapsules.

Supplementary Figure 7 NHP omental histology and western blot images of lead material implants.

(a) Representative MT and HE stained histology of biopsied omental tissue 4 weeks post-implantation in cynomolgus macaque, n = 3. (b) Western-blot images used for SMA quantification of protein extracted from the top three alginate analogue spheres and control spheres (n = 3).

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Vegas, A., Veiseh, O., Doloff, J. et al. Combinatorial hydrogel library enables identification of materials that mitigate the foreign body response in primates. Nat Biotechnol 34, 345–352 (2016).

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