3D Printing in Triggered Drug Delivery Devices: A Review

Triggered drug delivery devices use external stimulus to trigger the release of the drugs from the device. By controlling the exposure of the stimuli, it would allow for the control over the timing, duration and amount of drug being released from the device, improving drug efficacy. 3D printing uses on-demand deposition and crosslinking of materials to fabricate a product, increasing the customisability of the design and internal structure. By using 3D printing to fabricate triggered drug delivery devices, certain advantages such as complex geometries, gradient compositions, multi-material structures and embedded components can be conferred to the printed devices. In this review paper, triggered drug delivery devices which are fabricated using 3D printing techniques such as vat photopolymerisation and material extrusion are discussed. The advancement in certain areas of 3D printing, such as in multi-material 3D printing and hybrid additive manufacturing, which presents tremendous opportunities for fabricating future triggered drug delivery devices will also be reviewed.