Less invasive topical chemotherapies have emerged as alternatives, but their widespread uses have been hindered by both the painful size of the microneedles and the rapidly dissolving behavior of polymers used in the treatments.

Now, Purdue University innovators have created a novel wearable patch to help address the issues and provide an improved treatment experience for people with melanoma. The technology is published in the journal ACS Nano.

"We developed a novel wearable patch with fully miniaturized needles, enabling unobtrusive drug delivery through the skin for the management of skin cancers," said Chi Hwan Lee, a Purdue assistant professor of biomedical engineering and mechanical engineering. "Uniquely, this patch is fully dissolvable by body fluids in a programmable manner such that the patch substrate is dissolved within one minute after the introduction of needles into the skin, followed by gradual dissolution of the silicon needles inside the tissues within several months."

Lee said this gradual slow dissolution of the silicon nanoneedles allows for long-lasting and sustainable delivery of cancer therapeutics.

"The uniqueness of our technology arises from the fact that we used extremely small but long-lasting silicon nanoneedles with sharpened angular tips that are easy for their penetration into the skin in a painless and minimally invasive manner," Lee said.

The Purdue innovators developed a novel design of bioresorbable silicon nanoneedles that are built on a thin, flexible and water-soluble medical film. The water-soluble film serves as a temporary holder that can be conformably interfaced with the soft, curvilinear surface of the skin during the insertion of the nanoneedles, followed by rapid, complete dissolution within a minute.

The surface of the nanoneedles is configured with nanoscale pores and provides a large drug loading capacity comparable to those using conventional microneedles.

Lee said the nanoneedles could deliver the chemotherapeutic drugs to target melanoma sites in a sustainable manner. The silicon nanoneedles are biocompatible and dissolvable in tissue fluids, such that they can be completely resorbed in the body over months in a harmless manner.

This work is supported by the Air Force Office of Scientific Research (AFOSR: FA2386-18-1-40171).

Lee said he started working on this type of technology after seeing his daughter express fearful thoughts about needles when receiving vaccinations.

Story Source:

Materials provided by Purdue University. Original written by Chris Adam. Note: Content may be edited for style and length.

Journal Reference:

1. Hyungjun Kim, Heung Soo Lee, Yale Jeon, Woohyun Park, Yue Zhang, Bongjoong Kim, Hanmin Jang, Baoxing Xu, Yoon Yeo, Dong Rip Kim, Chi Hwan Lee. Bioresorbable, Miniaturized Porous Silicon Needles on a Flexible Water-Soluble Backing for Unobtrusive, Sustained Delivery of Chemotherapy. ACS Nano, 2020; DOI: 10.1021/acsnano.0c02343