Near-infrared light activated rapidly separable polymeric microneedles for transdermal biologics delivery

Abstract

Polymeric microneedles (PMNs) are an attractive transdermal drug delivery approach with minimal invasiveness and improved patient compliance. However, it is uncomfortable and inconvenient for patients to wear a PMN patch for hours or days until complete payload release. Here, we report a facile strategy to fabricate rapidly separable PMN arrays activated by near-infrared (NIR) light (NIR-RS-PMN) with enhanced mechanical strength through introduction of a photothermal-sensitive spacer integrating plasmonic gold nanorods into a biocompatible sodium hyaluronate matrix. Under NIR irradiation, the NIR-RS-PMN achieved rapid separation of the patch backing and microneedles within 1 min. The loaded bioactive therapeutics, e.g., insulin and RNA, were well-preserved during fabrication, NIR irradiation, and 20-day storage at room temperature. The NIR-RS-PMN was well tolerated by rats without skin irritation. Its feasibility for biologics delivery was further established by the treatment of diabetic rats with insulin encapsulated PMNs. The innovative PMNs increase ease of use and achieve effective and precise payload delivery, which may increase access to biopharmaceuticals and vaccines in remote and resource-limited communities.

Keywords

• Rapidly separable polymeric microneedles
• Transdermal drug delivery
• Gold nanorods
• Photothermal effect
• Insulin