Thermomechanical Soft Actuator for Targeted Delivery of Anchoring Drug Deposits to the GI Tract

Abstract

Current systemic therapies for inflammatory gastrointestinal (GI) disorders are unable to locally target lesions and have substantial systemic side effects. Here, a compact mesoscale spring actuator capable of delivering an anchoring drug deposit to point locations in the GI tract is demonstrated. The mechanism demonstrated here is intended to complement existing ingestible capsule-based sensing and communication technologies, enabling treatment based on criteria such as detected GI biomarkers or external commands. The 3D-printed actuator has shown on command deployment in 14.1 ± 3.0 s, and a spring constant of 25.4 ± 1.4 mN mm−1, sufficient to insert a spiny microneedle anchoring drug deposit (SMAD) into GI tissue. The complementary SMAD showed a 22-fold increase in anchoring force over traditional molded microneedles, enabling reliable removal from the actuator and robust prolonged tissue attachment. The SMAD also showed comparable drug release characteristics (R2 = 0.9773) to penetrating molded microneedles in agarose phantom tissue with a drug spread radius of 25 mm in 168 h. The demonstrated system has the potential to enable on command delivery and anchoring of drug-loaded deposits to the GI mucosa for sustained treatment of GI inflammation while mitigating side effects and enabling new options for treatment.