A retrievable implant for the long-term encapsulation and survival of therapeutic xenogeneic cells

Nat Biomed Eng. 2020 Aug;4(8):814-826. doi: 10.1038/s41551-020-0538-5. Epub 2020 Mar 30.


The long-term function of transplanted therapeutic cells typically requires systemic immune suppression. Here, we show that a retrievable implant comprising a silicone reservoir and a porous polymeric membrane protects human cells encapsulated in it after implant transplantation in the intraperitoneal space of immunocompetent mice. Membranes with pores 1 µm in diameter allowed host macrophages to migrate into the device without the loss of transplanted cells, whereas membranes with pore sizes <0.8 µm prevented their infiltration by immune cells. A synthetic polymer coating prevented fibrosis and was necessary for the long-term function of the device. For >130 days, the device supported human cells engineered to secrete erythropoietin in immunocompetent mice, as well as transgenic human cells carrying an inducible gene circuit for the on-demand secretion of erythropoietin. Pancreatic islets from rats encapsulated in the device and implanted in diabetic mice restored normoglycaemia in the mice for over 75 days. The biocompatible device provides a retrievable solution for the transplantation of engineered cells in the absence of immunosuppression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Capsules
  • Cell Transplantation / instrumentation
  • Cell Transplantation / methods*
  • Coated Materials, Biocompatible
  • Diabetes Mellitus, Experimental / therapy
  • Equipment Design
  • Erythropoietin / genetics
  • Erythropoietin / metabolism
  • Foreign-Body Reaction / prevention & control
  • Graft Survival*
  • HEK293 Cells
  • Humans
  • Islets of Langerhans
  • Islets of Langerhans Transplantation / instrumentation
  • Islets of Langerhans Transplantation / methods
  • Mice
  • Permeability
  • Prostheses and Implants*
  • Rats
  • Transplantation, Heterologous


  • Capsules
  • Coated Materials, Biocompatible
  • Epo protein, mouse
  • Erythropoietin