The research objective of this award is to use a laser-based rapid prototyping process in order to fabricate patient-specific middle ear implants. Middle ear implants will be fabricated with appropriate design features, including geometry and weight, for a given patient. In addition, inorganic-organic hybrid materials that demonstrate acoustic transmission, stability, sound transmission, and stiffness properties similar to those of natural bone will be prepared for use in these implants. The approach will involve biological, chemical, and mechanical characterization of materials created using the laser-based rapid prototyping process; process-oriented computational geometric analysis for fabrication of patient-specific middle ear implants; and functional characterization of patient-specific middle ear implants.
If successful, the benefits and broader impacts of this research will be to provide new techniques for rapid prototyping of middle ear implants and other patient-specific medical devices. It is anticipated that patient-specific middle ear implants will provide improved sound transmission for longer periods of time than conventional implants. In addition, the models developed in the proposed research program will be useful for examining the mechanics and geometry of other irregularly shaped objects, including natural tissues, geophysical features, and other irregular surfaces. From an educational perspective, the proposed project will be tightly integrated with the training objectives of both the biomedical engineering program at the University of North Carolina and the bio-manufacturing program at North Carolina State University. Both graduate students and undergraduate students from underrepresented backgrounds will be recruited to participate in the proposed research program, with undergraduate student support coming from a currently-funded Research Experiences for Undergraduates program.
Novel middle ear bone prostheses that provide improved sound transmission for longer periods of time are demanded by patients who have hearing difficulities. Cost reduction is also a growing influence in the design and use of middle ear bone prostheses. Mass-produced implants are produced out of various materials in several designs; however, these designs do not sufficiently take the anatomy of a given patient into account. One approach for increasing the functionality and lowering the cost of middle ear bone prostheses involves the development of patient-specific implants using an additive, layer-by-layer approach known as rapid prototyping. In this work, we have used rapid prototyping methods and microscale replication methods to process biomedical polymers with potential use in small-scale prostheses. For example, we examined microscale replication (a molding approach) to create replicas of two- and three-dimensional structures that were originally created using a laser rapid prototying method. We also examined use of a biocompatible molecule, riboflavin, for facilitating the chemical reactions that are used to create polymers in the laser rapid prototying method. Riboflavin was determined to be much less cytotoxic than conventional molecules, which are known as photoinitiators. In addition, we created a series of Saturday morning lectures and scientific demonstrations for young people in the broader community that take place at the North Carolina Museum of Natural Sciences in downtown Raleigh. Finally, the PI worked with the Carolina-South Atlantic Chapter of the International Society for Pharmaceutical Engineering to create a Biotechnology Day at the North Carolina Museum of Natural Sciences; the first annual Biotechnology Day took place on June 30, 2012. We anticipate holding a second Biotechnology Day in April 2013.
