title: Prevascularized silicon membranes for the enhancement of transport to implanted medical devices.
abstract: Recent advances in drug delivery and sensing devices for in situ applications are limited by the diffusion-limiting foreign body response of fibrous encapsulation. In this study, we fabricated prevascularized synthetic device ports to help mitigate this limitation. Membranes with rectilinear arrays of square pores with widths ranging from 40 to 200 μm were created using materials (50 μm thick double-sided polished silicon) and processes (photolithography and directed reactive ion etching) common in the manufacturing of microfabricated sensors. Vascular endothelial cells responded to membrane geometry by either forming vascular tubes that extended through the pore or completely filling membrane pores after 4 days in culture. Although tube formation began to predominate overgrowth around 75 μm and continued to increase at even larger pore sizes, tubes formed at these large pore sizes were not completely round and had relatively thin walls. Thus, the optimum range of pore size for prevascularization of these membranes was estimated to be 75-100 μm. This study lays the foundation for creating a prevascularized port that can be used to reduce fibrous encapsulation and thus enhance diffusion to implanted medical devices and sensors. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1602-1609, 2016.
authors: Stephen A. Wynn Institute for Vision Research, Department of Opthamology and Visual Sciences, The University of Iowa, Iowa City, Iowa.
authors: Kristan S
authors: KS
authors: Worthington
authors: Stephen A. Wynn Institute for Vision Research, Department of Opthamology and Visual Sciences, The University of Iowa, Iowa City, Iowa.
authors: Luke A
authors: LA
authors: Wiley
authors: Stephen A. Wynn Institute for Vision Research, Department of Opthamology and Visual Sciences, The University of Iowa, Iowa City, Iowa.
authors: Robert F
authors: RF
authors: Mullins
authors: Stephen A. Wynn Institute for Vision Research, Department of Opthamology and Visual Sciences, The University of Iowa, Iowa City, Iowa.
authors: Budd A
authors: BA
authors: Tucker
authors: Department of Chemical and Biochemical Engineering, The University of Iowa, Iowa City, Iowa. eric-nuxoll@uiowa.edu.
authors: Eric
authors: E
authors: Nuxoll
mesh_terms: D000818:Animals; D002460:Cell Line; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D008567:Membranes, Artificial; D051379:Mice; D016062:Porosity; D019736:Prostheses and Implants; D012825:Silicon / Q000737:chemistry*
chemical_list: D008567:Membranes, Artificial; D012825:Silicon
keywords: implantable drug delivery; medical device membrane; microelectromechanical systems (MEMS); silicon; vascularized medical implant