title: Metabolic biofouling of glucose sensors in vivo: role of tissue microhemorrhages.
abstract: OBJECTIVE
  Based on our in vitro study that demonstrated the adverse effects of blood clots on glucose sensor function, we hypothesized that in vivo local tissue hemorrhages, induced as a consequence of sensor implantation or sensor movement post-implantation, are responsible for unreliable readings or an unexplained loss of functionality shortly after implantation.
  
  
  METHODS
  To investigate this issue, we utilized real-time continuous monitoring of blood glucose levels in a mouse model. Direct injection of blood at the tissue site of sensor implantation was utilized to mimic sensor-induced local tissue hemorrhages.
  
  
  RESULTS
  It was found that blood injections, proximal to the sensor, consistently caused lowered sensor glucose readings, designated temporary signal reduction, in vivo in our mouse model, while injections of plasma or saline did not have this effect.
  
  
  CONCLUSIONS
  These results support our hypothesis that tissue hemorrhage and resulting blood clots near the sensor can result in lowered local blood glucose concentrations due to metabolism of glucose by the clot. The lowered local blood glucose concentration led to low glucose readings from the still functioning sensor that did not reflect the systemic glucose level.
authors: Center for Molecular Tissue Engineering, School of Medicine, University of Connecticut, Farmington, Connecticut, USA. klueh@nso.uchc.edu
authors: Ulrike
authors: U
authors: Klueh
authors: Zenghe
authors: Z
authors: Liu
authors: Ben
authors: B
authors: Feldman
authors: Timothy P
authors: TP
authors: Henning
authors: Brian
authors: B
authors: Cho
authors: Tianmei
authors: T
authors: Ouyang
authors: Don
authors: D
authors: Kreutzer
mesh_terms: D000818:Animals; D057219:Biofouling; D015374:Biosensing Techniques / Q000379:methods*; D001777:Blood Coagulation; D001786:Blood Glucose / Q000032:analysis* / Q000378:metabolism; D015190:Blood Glucose Self-Monitoring / Q000379:methods; D004195:Disease Models, Animal; D004867:Equipment Design; D005260:Female; D006470:Hemorrhage / Q000503:physiopathology*; D006801:Humans; D051379:Mice; D008813:Mice, Inbred ICR; D019736:Prostheses and Implants; D012680:Sensitivity and Specificity; D013997:Time Factors
chemical_list: D001786:Blood Glucose