Protein encapsulation in polymeric microneedles by photolithography

Area of Science:

• Biomaterials Science
• Drug Delivery Systems
• Nanotechnology

Background:

• Growing interest in biocompatible polymeric microneedles for biomolecule delivery.
• Need for fabrication methods compatible with drug stability and enabling efficient encapsulation.
• Potential for microneedles to achieve higher drug loading than other technologies.

Purpose of the Study:

• To fabricate and characterize polymeric microneedles for drug encapsulation using photolithography.
• To evaluate the stability, release kinetics, and in vitro skin permeation of an encapsulated model protein drug.
• To assess the biocompatibility and cytotoxicity of the fabricated microneedles.

Main Methods:

• Photolithography used for fabricating polymeric microneedles.
• Encapsulation of bovine serum albumin (BSA) as a model protein drug.
• Analysis of drug distribution, structural integrity, in vitro release, and in vitro skin permeation.
• Cytotoxicity testing on three different cell lines.

Main Results:

• Uniform drug distribution within the microneedle array.
• Encapsulated BSA retained its structural characteristics (primary, secondary, tertiary).
• Rapid in vitro release of BSA within 6 hours, followed by a similar permeation profile through rat skin.
• High cell viabilities observed, indicating microneedle innocuousness.

Conclusions:

• Polymeric microneedle arrays are a viable drug carrier system.
• Potential application for the delivery of proteins, peptides, and vaccines.
• Demonstrated feasibility of photolithography for creating stable, drug-loaded microneedles.