| Microfabrication technology, with many technologies originally developed for producing computer chips, is being used to fabricate particulate drug delivery microdevices with uniform dimensions, well-defined and asymmetrical structures, multiple components, and multiple functions. For this application, conventional silicon-based microfabrication techniques have some drawbacks, such as the use of expensive cleanroom-based facilities and limited ability for processing polymers. In this dissertation, polymer-based microfabrication technology, in particular soft lithography, is used to produce particulate polymeric microstructures for drug delivery. Plate-like particulate polymeric microstructures made of various biomedical polymers with different sizes and shapes have been created. They may be used as drug-carrying vehicles in a number of applications such as ocular drug delivery. Microstructures with single reservoir have been produced by polymerizing liquid resin filled in ring-shaped recessed microfeatures. Microstructures containing multiple reservoirs have also been fabricated by combining polymer printing and embossing. These reservoir-containing microstructures may be used for oral delivery or macromolecular drugs. Capsule-like microstructures with model drug encapsulated by a biodegradable polymer have been fabricated. This type of microstructures may be used as injectable system for sustained drug delivery. By combining two polymer layers with different swelling ratios together, we have produced self-foldable microstructures that may be used as a novel strategy to enhance mucoadhsion and drug permeation in transmucosal drug delivery. In conclusion, the polymeric microstructures produced in this dissertation have potential to be used in a variety of drug delivery applications and polymer-based microfabrication technology hold promise to produce the highly engineered, multi-functional, and "intelligent" next generation drug delivery microdevices. |
