# An implantable dual-chamber capsule with three release modes for site-specific delivery and enhanced therapeutic efficacy

## TL;DR

This paper introduces a small implantable capsule that can release drugs in three different ways, improving precision and effectiveness in drug delivery.

## Contribution

The capsule's dual-reservoir design and magnetically controlled release modes offer a novel solution for site-specific drug delivery.

## Key findings

- The capsule achieves a 76% drug retention rate with precise dosing of 0.01 mL.
- It maintains stable performance under thermal and mechanical stress.
- In vivo tests show therapeutic outcomes comparable to subcutaneous injection.

## Abstract

Precise and flexible drug delivery is increasingly required in clinical therapy, yet most implantable systems remain constrained by limited selectivity, low loading capacity, and bulky size. Here, we present an implantable capsule that employs magnetically actuated vibration of an internal metallic cantilever to achieve magnetically controlled release. The capsule integrates a dual-reservoir structure, enabling the device to load two drugs and support multimodal release through three independent modes. Experimental evaluation demonstrates a drug retention rate of 76% and a single release volume of 0.01 mL with fluctuations within ±0.0005 mL, while maintaining a miniature form factor (13 × 5 × 5 mm3) and stable performance under thermal (45 °C) and mechanical (50 g) stress. In vivo studies further confirm that insulin and lidocaine hydrochloride delivered by this capsule achieve therapeutic outcomes comparable to subcutaneous injection. Combining compactness, robustness, and multi-mode controllability, this system supports long-term implantable drug administration.

•Dual-reservoir magnetostrictive capsule enables wireless AMF-triggered drug release•Cantilever frequency selection enables reliable switching among three release modes•Miniature 13 × 5 × 5 mm3 capsule achieves76% drug loading with repeatable dosing•Stable release under depletion, 45°C heating and 50 g load

Dual-reservoir magnetostrictive capsule enables wireless AMF-triggered drug release

Cantilever frequency selection enables reliable switching among three release modes

Miniature 13 × 5 × 5 mm3 capsule achieves76% drug loading with repeatable dosing

Stable release under depletion, 45°C heating and 50 g load

Drug delivery system; Biotechnology; Biodevices; Materials science; Magnetic materials