Design Criteria

An up-close view of microneedles; they’re right on point! 🙂

  • Wearability and Flexibility
    • CGM w/ biosensors can significantly decrease HbA1c (glycated hemoglobin) levels [11]
    • Penetrates superficial vascular plexus rather than subcutaneous tissue [11]
      • Reduces invasiveness and pain [11]
  • Precision
    • Can detect abnormalities in blood glucose [11]
    • Should be a better predictor of other related conditions like hypoglycemia than finger-pricking method [11]
    • Close estimate of glucose levels in interstitial fluids compared to in the blood [11]
    • Increased sensitivity, lower sample volume, fast response time [11]

 

Biosensor Diagram; as shown here, the microneedle must be able to enter the body into the more intrinsic layers of the skin. Talk about micromanaging! 😮

 

  • Repeatability 
    • As often as every 5 min (288 times a day) [11]
    • Improved sensor life compared to that of 2-week lasting commercialized CGMs [11]
    • Skin permeability [11]
    • Must assess issues such as biofouling [11]
  • Cost-efficient
    • Current commercially available CGMs cost hundreds of dollars [11]
    • Must be able [11]
  • Biocompatibility [11]
  • Size and Shape [11]

 

Breakdown of Biosensors; biosensors have many different parts to them. Brrrr… I’m sense-ing something intriguingly complicated up ahead~ 😉

 

  • Monitoring of blood glucose in interstitial fluids using wearable biosensors
    • Enzymatic Biosensor -> Metallic electrodes and microneedle technology as detection method for glucose [11]
    • Non-Enzymatic Biosensor w/ amperometry -> Measuring cell current [11]
    • Fluorescent Probe attached with glucose-binding protein -> reduces volume of fluid needed but no CGM applications [11]

 

References:

[11] L. Johnston, G. Wang, K. Hu, C. Qian, and G. Liu, “Advances in Biosensors for Continuous Glucose Monitoring Towards Wearables,” Frontiers in Bioengineering and Biotechnology, vol. 9, Aug. 2021, doi: https://doi.org/10.3389/fbioe.2021.733810.