Portable Therapy Delivery

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. Advanced wound healing devices generally lack true portability and home-use capability due to bulk, complexity, and/or power requirements. One potential unmet clinical need is the integration of a portable wearable design with modern and sometimes de novo components e.g., specialized microfluidic channels, reliable iontophoretic actuators, and programmable temporal controls.

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) 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 portable therapy delivery aspects to help overcome certain mechanical and materials engineering challenges. This includes time-programmed sequential dual therapy protocol that delivers electric field (EF) therapy followed by iontophoretic fluoxetine delivery. This temporal sequencing specifically targets the inflammation-to-proliferation transition critical for proper wound healing. This case also introduces new microfluidic channel fluid-switching architecture that enables a single actuator to deliver multiple distinct therapies sequentially by actively exchanging fluids through an integrated pump module. The dual-reservoir system (supply and waste chambers) with stepper motor-driven plunger mechanism allows pre-loaded EF solution to be replaced with fluoxetine solution after a certain periods. The flexible iontophoretic actuator design incorporates cross-linked cation-selective hydrogel within novel double-fluted polydimethylsiloxane protrusions, providing mechanical stability despite the hydrogel's inherent brittleness. The progressive multi-layer curing process within the double-fluted geometry relies on mechanical interlocking rather than problematic surface chemistry adhesion, while certain protrusion height maintains critical wound bed spacing for adequate gas exchange. The device's programmable control architecture efficiently integrates microcontroller, digital-to-analog conversion, data logging, and low-power short-range communications components for pre-programmed, multi-day treatment protocols tied to real-time performance monitoring.

Applications

• diagnostics – wound healing
• therapeutics – wound healing

Features/Benefits

• Allows healthcare providers to configure treatment regimens in clinical settings while enabling patient home use with remote monitoring capability, which is seen by UCSC as a critical feature for translating advanced bioelectronic therapy from hospital to ambulatory settings.
• Strategic timing exploits the distinct mechanisms of action: EF therapy during early inflammation promotes galvanotactic cell migration and reinforces endogenous wound electric fields, while delayed fluoxetine delivery modulates later-stage inflammation without impairing the necessary early inflammatory response.
• A dual-reservoir system (supply and waste chambers) with stepper motor-driven plunger mechanism eliminates the need for multiple separate devices or manual intervention.
• Progressively-cured cross-linked 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.

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