Percutaneous window chamber method for chronic intravital microscopy of sensor-tissue interactions

Area of Science:

• Biomedical Engineering
• Microcirculation Research
• Implantable Sensor Technology

Background:

• Previous dorsal skin-fold window chamber models limited glucose sensor research due to physiological constraints.
• A novel percutaneous, one-sided window chamber model was developed for rodent dorsum studies.
• This model offers an expanded subcutaneous area and reduced tissue restriction compared to prior systems.

Purpose of the Study:

• To develop and validate a percutaneous dorsal skin-fold window chamber for implantable sensor research.
• To characterize physiological factors influencing glucose sensor performance in vivo.
• To enable real-time visualization of microvascular dynamics and mass transport at the sensor-tissue interface.

Main Methods:

• Surgical implantation of sensors into the subcutis beneath a 15 mm acrylic window.
• Noninvasive intravital microscopy and laser Doppler flowmetry for quantifying microvascular network changes and red blood cell perfusion.
• Combined interstitial glucose monitoring with intravital fluorescence microscopy using fluorescein and dextrose bolus injections.

Main Results:

• The percutaneous window chamber effectively models sensor surface morphology effects on neovascularization.
• Real-time monitoring of microvascular networks and tissue perfusion is achievable.
• Observed variability in tissue response and sensor migration necessitates further refinement.

Conclusions:

• The percutaneous optical window facilitates direct, real-time imaging of microvascular network dynamics and tissue encapsulation.
• Visualizing microvessels via fluorescent dye and glucose injections offers a valuable method to study mass transport at the sensor surface.
• This model is crucial for understanding tissue-sensor interactions and optimizing implantable sensor design.