Fabrication of Hollow Microneedle Patch With Controllable Microstructure for Cell Therapy

Microneedles pierce the epidermis to create micro-channels for drug delivery in a painless and minimally invasive way. With these micro-channels, large macromolecules can penetrate through the complex barriers of skin to reach the target tissue. Cell therapy delivers cells to repair or replace damaged tissue and generally involves direct injection into the tissue. But it has drawbacks, such as the risk of infection, low patient compliance due to pain at injection, leakage of cell suspensions from the injection site and cell damage during injection. Hollow microneedle arrays with various microstructures are successfully fabricated by micromolding, where their microstructure can be controlled by the laser power and the drawing pattern. The cells are easily loaded on top of hollow microneedles. The results show that PMMA hollow microneedles have good biocompatibility and the cells can be successfully delivered to the acellular tissue. This study confirms that the cells can be effectively delivered and penetrate into tissue by a hollow microneedle patch. The delivered cells proliferate and distribute evenly in the tissue. Hollow microneedles provide a minimally invasive route for effectively delivering cells into tissue. This novel strategy has potential application for cell therapy.