New Polyester Biomaterials: Facile Preparation of Tunable Rapidly Degrading Elastomer Devices Valerie Sheares Ashby, University of North Carolina at Chapel Hill, DMR # Present Materials: –Poly( L -lactic acid), poly(glycolic acid) and poly(  - caprolactone) are the most commonly used degradable polyester materials for today’s biomedical applications. Present Material Drawbacks: –These polyesters are often crystalline and hydrophobic. Both properties lead to degradation rates on the order of six months to several years. Moreover, the mechanical properties are limited with most being hard materials with low resilience. Materials Need: –There is a need for flexible materials capable of withstanding dynamic environments needed for soft tissue regeneration, engineering scaffolds and drug depot systems. There is also a need for rapidly degrading biocompatible materials. New Materials Design: –We have designed a class of completely non- crystalline, degradable elastomeric materials using a versatile linear prepolymer approach. The resulting materials have easily tailored mechanical and degradation properties. To our knowledge, no examples that combine this ease of property control with the ease of fabrication exist. These materials can be designed to degrade very rapidly (less than 30 days). However, materials with longer term degradation rates (60 % mass loss in 8 weeks) were also demonstrated. Furthermore, the mechanical properties of these materials can be tuned over a broad range to specifically align with multiple natural tissues. The liquid nature of the prepolymers allows for facile fabrication into multiple forms allowing for the rational design of shape specific devices. Finally, all prepolymers and elastomers with and without the soluble fraction had toxicity scores of 0.0, indicating no cytotoxic response. Polymer degradation studies. Materials can be designed to degrade completely in as little as 30 days. Polymer Fabrication Studies. Examples of polymer fabrication to embossed films of various sizes and shapes. Uniform, individual particles also possible. 200 μm3 μm 20 μm500 μm

New Polyester Biomaterials: Facile Preparation of Tunable Rapidly Degrading Elastomer Devices Valerie Sheares Ashby, University of North Carolina at Chapel Hill, DMR # Interest Meeting: 65 people in attendance at the interest meeting on September 7, 2005; 44 students completed membership applications - 14 graduate students and 30 undergraduates from various majors including chemistry, physics, biomedical engineering, pharmacy, and pharmacology; 10 faculty and staff members from different depts. present Programs/Activities: undergraduate tutoring program, career services resume workshop, navigating science courses panel discussion, high school tutoring and outreach program, holiday social with National Society of Black Engineers and National Black MBA Association First Year Achievements: Domonique Downing, a junior chemistry major and undergraduate researcher in the lab of Professor Valerie Ashby was the National winner of the NOBCChE undergraduate research competition held at the national meeting in The award consists of a $1000 prize, an all expenses paid trip to the conference, and a paid summer internship at Rohm and Haas Co. Faculty Involvement: The PI for this NSF DMR award, Valerie Ashby, is the faculty advisor for this organization. Membership fees for students who joined the organization by November 2005 were paid by the NSF-STC directed by Joe DeSimone. (L-R) A) Connell Cunningham, 4 th yr. chem. grad student addressing the interest group. B) Domonique Downing, national winner of NOBCChE undergrad. research competition, C) Valerie Ashby, UNC NOBCChE Advisor addressing the interest group. Outreach Highlight: New NOBCChE (National Organization of Black Chemists and Chemical Engineers) Chapter Established at UNC-Chapel Hill in September 2005 ABC