Conventional ossicular replacement prostheses have demonstrated several problems during clinical use, including migration, puncture of the eardrum, difficulty in shaping the prostheses, and reactivity with the surrounding tissues. Novel materials and prostheses that provide improved sound transmission for longer periods of time are demanded by patients and surgeons. In this work, they hypothesize that two photon polymerization may be used to fabricate ossicular replacement prostheses with patient-specific designs and suitable chemical, biological, mechanical, and functional properties for long-term in vivo use. The quadratic character of the two photon absorption probability and the well-defined polymerization threshold of this system will allow one to overcome the diffraction limit and achieve features as small as 200 nm. Two photon polymerization provides several advantages over conventional techniques for scalable production of ossicular replacement prostheses and other small-scale medical devices. First, the raw materials used in this process are widely available and inexpensive. Second, two photon polymerization can be set up in a conventional clinical environment (e.g., an operating room) that does not contain cleanroom facilities. Third, two photon polymerization of ossicular replacement prostheses is an rapid, straightforward, single-step process, as opposed to conventional multiple-step fabrication techniques.
In this work, we hypothesized that two photon polymerization may be used to create medical devices with small scale features, including ossicular replacement prostheses, with patient-specific designs and appropriate biological and mechanical functionalities for use inside the body. One unique attribute of the two photon polymerization approach is that features as small as 200 nm can be obtained using this approach. Two photon polymerization exhibits several advantages over other techniques for scalable production of medical device with small-scale features. First, the raw materials used in two photon polymerization are inexpensive and can be obtained from a variety of sources. Second, two photon polymerization can be set up in a conventional environment, including in an operating room; no cleanroom facilities are needed. Third, two photon polymerization is a rapid and single-step process. The outcomes of the project include completion of the following activities: (a) use of two photon polymerization to create structures with small-scale features out of a zirconium-based material; tabletop biological studies examined the interactions of human bone marrow stromal cells with these materials. (b) use of atomic layer deposition to grow ceramic (e.g., titanium oxide and zinc oxide) coatings on nanostructured surfaces based on nanoporous aluminum oxide; tabletop biological studies examined the interactions of cells known as fibroblasts, cells known as macrophages, and proteins with these materials We are now working with a manufacturer of metals for medical device industry to see if metals with small-scale features similar to the two photon polymerization-fabricated and atomic layer deposition-coated materials can be translated to use in medical devices.
