Soft Injectable Sutures for Dose-Controlled and Continuous Drug Delivery.

Transdermal drug delivery offers a promising alternative to traditional methods like oral ingestion and hypodermic injection. Hypodermic injections are painful, while oral ingestion requires higher doses due to enzymatic degradation and poor absorption. While microneedles address the pain issue, they are limited to delivering small amounts of drugs and can be impractical due to peeling off with motion and sweat. Herein, we propose soft injectables using drug-carrying sutures for painless and localized sustained delivery in the dermis. These sutures can remain in place during delivery and are suitable for all skin types. Surgical sutures can also serve as open capillary microfluidic channels carrying drug from a wearable drug reservoir to enable long-term (weeks to months) transdermal drug delivery. Our experiments focus on delivering 5-fluorouracil, a cancer drug, and rhodamine B, a drug model. A fixed-length suture of 60 cm delivers 0.43 mg of 5-flurouracil in 15 minutes. Our experiments also demonstrate a continuous drug delivery of rhodamine B for over 8 weeks at a rate of 0.0195 mL per hour. Our results highlight that soft injectable sutures are promising candidates for long-term sustained delivery of varying quantities of drugs over weeks period compared to hypodermic injection, oral ingestion, or microneedles. This article is protected by copyright. All rights reserved.