UMMS Affiliation

Program in Molecular Medicine

Publication Date


Document Type

Article Postprint


Animals; Foreign-Body Reaction; Mice; Mice, Inbred C57BL; Primates


Biomaterials | Biomedical Devices and Instrumentation | Biotechnology | Immunity


The efficacy of implanted biomedical devices is often compromised by host recognition and subsequent foreign body responses. Here, we demonstrate the role of the geometry of implanted materials on their biocompatibility in vivo. In rodent and non-human primate animal models, implanted spheres 1.5 mm and above in diameter across a broad spectrum of materials, including hydrogels, ceramics, metals and plastics, significantly abrogated foreign body reactions and fibrosis when compared with smaller spheres. We also show that for encapsulated rat pancreatic islet cells transplanted into streptozotocin-treated diabetic C57BL/6 mice, islets prepared in 1.5-mm alginate capsules were able to restore blood-glucose control for up to 180 days, a period more than five times longer than for transplanted grafts encapsulated within conventionally sized 0.5-mm alginate capsules. Our findings suggest that the in vivo biocompatibility of biomedical devices can be significantly improved simply by tuning their spherical dimensions.


Biomaterials, Biomedical materials, Implants

Rights and Permissions

Author accepted manuscript posted after 6 months as allowed by the publisher's author rights policy at

DOI of Published Version



Nat Mater. 2015 Jun;14(6):643-51. doi: 10.1038/nmat4290. Epub 2015 May 18. Link to article on publisher's site

Journal/Book/Conference Title

Nature materials


Full author list omitted for brevity. For the full list of authors, see article.

Related Resources

Link to Article in PubMed

PubMed ID