Dressing for Bioelectronic Smart Bandage

Background

Chronic wounds affect over 6.5 million people in the United States costing more than $25B annually. 23% of military blast and burn wounds do not close, affecting a military patient's bone, skin, nerves. Moreover, 64% of military trauma have abnormal bone growth into soft tissue. Slow healing of recalcitrant wounds is a known and persistent problem, with incomplete healing, scarring, and abnormal tissue regeneration. Precise control of wound healing depends on physician's evaluation, experience. Physicians generally provide conditions and time for body to either heal itself, or to accept and heal around direct transplantations, and their practice relies a lot on passive recovery. While newer static approaches have demonstrated enhanced growth of non-regenerative tissue, they do not adapt to the changing state of wound, thus resulting in limited efficacy. One potential unmet clinical need is related to todays rigid form factors. Modern delivery systems lack adequate conformal capability to adapt to complex surfaces (e.g., feet, joints, curved surfaces) where chronic wounds frequently occur. If modern devices have semi-flexible printed circuit boards they have not maintained consistent wound contact during patient movement, leading to variable delivery rates and reduced efficacy.

Technology Description

To overcome these challenges, a research team at UC Santa Cruz (UCSC) has developed a more intelligent system and related devices and methods to control tissue regeneration towards better wound healing processes. UCSC’s Bioelectronics for Tissue Regeneration (BETR or a-Heal) aims to establish bidirectional communication between body and a bioelectronic interface that will guide and expedite tissue healing and regeneration. BETR’s dynamic, adaptive closed-loop architecture guides tissue along an optimal growth pathway. The custom hardware uses wearable biochemical and biophysical sensors to precisely determine current and wound states and actuators to deliver biochemical and biophysical interventions at relevant time points. Custom optics, software, and supporting logic is the adaptive learning system that connects camera, sensors, and actuators for optimal and directed temporal and spatial response. BETR’s evolving aims include the detection of predictive biomarkers to better assess healing and non-healing wound states, which factors into data-driven, closed-loop feedback controls.

This case’s subject matter focuses on a more conformable polydimethylsiloxane (PDMS)-hydrogel architecture. UCSC’s BETR’s / a-Heal’s flexible polyimide electrode integrated with PDMS body and strategically positioned protrusions maintains conformal contact across curved anatomical sites while preventing wound smothering and ensuring gas exchange. This research results features a cuttable/scalable tessellating reservoir design, having fixed alternating reservoirs with tessellating electrode patterns which enables customization to variable wound sizes while maintaining dual-therapy control across inner and outer delivery rings. Furthermore, the double-fluted cation-selective hydrogel cured within PDMS protrusions address challenges with brittleness through mechanical interlocking rather than adhesive chemistry.

Applications

• diagnostics – wound healing
• therapeutics – wound healing

Features/Benefits

• Current bioelectronic systems require separate devices for different wound dimensions; this research result features cuttable/scalable tessellating reservoir design to enables tailoring to variable wound sizes while maintaining dual-therapy controls.
• Represents a significant manufacturing achievement for integrating ion-exchange membranes in flexible devices.
• Conformal elastic modulus of flexible polyimide electrode integrated with PDMS body ~10-100 kPa matches wound tissue.
• Progressively-cured hydrogel layers helps address critical brittleness problem of cation-selective hydrogels (through mechanical interlocking vs. surface adhesion) and enables device flexibility essential for anatomical conformity and patient mobility.
• Preliminary porcine data shows statistically significant faster closure (p=0.0145) and 36.3% reduction in granulation tissue (p<0.005) at day 22 versus current standard of care.

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