We developed a microneedle system that integrates active-ingredient delivery with biocontainment, offering a convenient platform for future skincare and therapy.
We have developed a microneedle-based microneedle delivery system for active ingredient transport. The microorganisms can survive within the sealed cavities of the microneedles, where they secrete nutrients that are then delivered into the subcutaneous tissue through microchannels. These flexible microneedles hold the potential for future daily use as an easy "apply-and-go" solution, significantly simplifying skincare steps and reducing the time required for daily routines.
The microneedle-based delivery system takes the form of a transparent patch. It consists of three primary components: a backing patch, sealed cavities (for housing microorganisms), and the microneedles.
The microchannels, which are nano- to micron-sized, effectively prevent the passage of microorganisms while enabling the delivery of active ingredients via an in-situ reaction.
The mold for the microneedle-based delivery system was fabricated using PDMS. The system itself is composed of a PVA-cellulose composite material, engineered to achieve a balance between pliability and structural support. This unique texture allows the patch to conform effectively to the skin while providing the rigidity necessary for the microneedles to remain upright and penetrate the dermal layer. Furthermore, the hydrous nature of the material, coupled with its capacity to encapsulate nutrients, creates a microenvironment that supports bacterial survival for a designated period.
The system utilizes an engineered E. coli BL21 strain. This modified strain is endotoxin-free, rendering it relatively safe for human use. Moving forward, we will refine both the microneedle system and the purification methods for the target products to accelerate the deployment of this convenient platform in real-world applications. In terms of safety, the cavities within the delivery system form a closed environment where the bacteria will naturally die upon nutrient depletion. Furthermore, we have designed an L-arabinose-inducible "suicide switch" as part of the wet-lab implementation, providing a dual safeguard for the project.
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