Self-cleaning membrane to extend the lifetime of an implanted glucose biosensor.

Abstract

The lifetime and efficacy of a subcutaneously implanted glucose biosensor could be greatly improved by a self-cleaning membrane capable of periodic physical removal of adhered cells associated with the foreign body reaction. Previously, we reported a thermoresponsive double network nanocomposite (DNNC) membrane composed of poly(N-isopropylacrylamide) (PNIPAAm) and embedded polysiloxane nanoparticles. When the membrane was thermally cycled above and below its volume phase transition temperature (VPTT, ~33-35 °C), the associated deswelling and reswelling, respectively, led to in vitro cell release. Herein, this membrane design was tailored to meet the specific demands of a subcutaneously implanted glucose biosensor, and critical functional properties were assessed. First, N-vinylpyrrolidone (NVP) comonomer increased the VPTT to ~38 °C so that the membrane would be swollen and thus more permeable to glucose in the "off-state" (i.e., no heating) while residing in the subcutaneous tissue (~35 °C). Second, glucose diffusion kinetics though the DNNC membrane was experimentally measured in its deswollen and reswollen states. A cylindrical DNNC membrane with dimensions considered suitable for implantation (1.5 × 5 mm, diameter × length) was used to model the glucose diffusion lag time. In addition, the DNNC cylinder was used to observe dimensional changes associated with deswelling and reswelling. Noncytotoxicity was confirmed and self-cleaning was assessed in vitro in terms of thermally driven cell release to confirm the potential of the DNNC membrane to control biofouling.

• Authors: Alexander A Abraham, Ruochong Fei, Gerard L Coté, Melissa A Grunlan
• Journal: ACS applied materials & interfaces (ACS Appl Mater Interfaces) Vol. 5 Issue 24 Pg. 12832-8 (Dec 26 2013) ISSN: 1944-8252 [Electronic] United States
• PMID: 24304009 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)

Chemical References

• Acrylic Resins
• Hydrogels
• Siloxanes
• poly-N-isopropylacrylamide
• Glucose

Topics

• Acrylic Resins (chemistry)
• Biofouling (prevention & control)
• Biosensing Techniques (instrumentation, standards)
• Glucose (analysis)
• Hydrogels (chemistry)
• Nanocomposites (chemistry)
• Phase Transition
• Siloxanes (chemistry)
• Transition Temperature