Physical, Chemical, and Biological Characterization and Fabrication


   
      Figure 1.
Bar graph representation of the glass transition temperature (Tg) of 112 polymers in the polyarylate library. Polymers with different diacids are along the x-axis, and those with different pendent chains are along the Y-axis.

A
clear progression of Tg from low to high values suggests a correlation between chemical structure and Tg. Similar presentations can be prepared for surface hydrophilicity, mechanical properties and cell response.
     The Kohn Lab is committed to developing polymers via a combinatorial computational approach for use in advanced biomedical products including engineered living tissues and other bioactive and degradable devices. The conventional experimental approach to characterizing bioresponse and materials properties of polymers is clearly unsuitable for libraries of such enormous size. Kohn Lab research uses a wide range of the different types of computational modeling that have been applied to prediction of bioresponse (i.e., protein adsorption, cellular response) and materials characterization of polymeric biomaterials (i.e., glass transition temperature (Figure 1), air-water contact angle, modulus of elasticity, and degradation), before testing the most promising polymers. However, lack of high throughput evaluation methods has been a constraint to rapid screening of these polymers for specific applications.  To meet this need, techniques to provide a large number of polymers in a convenient format for use by other laboratories are under development.

     The Kohn Lab contains state-of-the-art polymer characterization equipment, and has developed and validated methods to measure physical, chemical, mechanical and bioresponse characteristics of libraries of polymers. The Kohn Lab is also exploring the impact of different fabrication techniques, because the way in which a particular test specimen is made can make a dramatic difference to its end use characteristics. The properties of a polymer are dramatically affected by the way in which it is shaped into an object. For example, both a styrofoam cup, which is opaque and a good insulator, and a transparent overhead projection sheet, are made of polystyrene.  Please see the pages below for current projects in the areas of characterization and fabrication of polymers.




  Physical, Chemical, and Biological Characterization and Fabrication