## 9 Tissue Engineering
### Incorporation of Lysine into PNIPAAm to Enhance Protein Adsorption  
[PERSON] and [PERSON]  
University of South Florida Department of Mechanical Engineering, Tampa, FL 33620, USA  
Developing methods to increase cell adhesion to the Poly(N-isopropylacrylamide) (PNIPAAm) polymer is essential to the development of new PNIPAAm based tissue engineering technology. Cell adhesion to PNIPAAm gels is poor due to minimal protein adsorption. Based on the observation that polylysine surface coating enhanced cell adhesion on PNIPAAm gels, we tested the hypothesis that incorporation of lysine monomers into the NIPAAm network would enhance protein adsorption. 10 \(\upmu\)m carboxylated polystyrene microparticles were coupled with fibronectin protein. The beads were then absorbed on the glass coverslips coated with the crosslinked PNIPAAm polymer and placed in a spinning disk machine where they were exposed to a range of hydrodynamic shear stresses. The experiment was conducted with PNIPAAm polymers of varying lysine percentages and in both the polymer's solvated and collapsed states. Integration of Cells with Silicon Devices for In Vitro Tissue Engineering of Functional Systems for Preclinical Drug Discovery and Toxicology  
[PERSON]  
Chief Scientist, Hesperos, Inc., Orlando, FL 32826, USA  
Professor, Nanoscience Technology, Chemistry, Biomolecular Science and Electrical Engineering, NanoScience Technology Center, University of Central Florida, Orlando, FL 32826, USA  
One of the primary applications of nanoscience in biology is the development of tailored interfaces to promote the integration of biological and non-biological material. The idea is to integrate microsystems fabrication technology and surface modifications with protein and cellular components, for initiating and maintaining self-assembly and growth into biologically, mechanically, and electronically interactive functional multi-component systems. Our research focus is on the establishment of functional human-on-a-chip systems to create organs and subsystems to model motor control, muscle function, myelination, and cognitive function, as well as cardiac subsystems. These systems utilize a pumpless platform with a serum free recirculating medium. The application of this new platform to drug discovery and toxicology research is to promote relevant model systems between the single cell level and animals or humans. UCF in collaboration with Hesperos has been constructing these systems with up to six organs and have demonstrated long-term (\(>\)28 days) evaluation of drugs and compounds, that have shown a similar response to results seen from clinical data or reports in the literature. Application of these systems for ALS, Alzheimer's, rare diseases, diabetes, and cardiac and skeletal muscle mechanistic toxicity will be presented as well as the development of in vitro PDPK models that are being used to predict in vivo results. Concurrent measurement of both efficacy and toxicity can also be done in the same system for therapeutic index estimation. Hesperos has received Phase II and Phase IIB SBIR grants from NCATS to apply advanced manufacturing technologies and automation to these systems in collaboration with NIST in addition support from pharmaceutical and cosmetic companies. This talk will also present the results of six workshops held at NIH to explore what is needed for the validation and qualification of these new systems. The Effect of Crystallization and Glass Transition Temperature in Thin Poly(D,L-Lactic Acid) Copolymers for Controlling Osteoblast Recruitment and Adhesion  
[PERSON] a, [PERSON] b and [PERSON] a Department of Chemical and Biomedical Engineering, University of South Florida, Tampa, FL 33620, USA; [PERSON]_ADDRESS] (U.I. ); [EMAIL_ADDRESS] (R.T.)  
b Department of Mechanical Engineering, University of South Florida, Tampa, FL 33620, USA; [EMAIL_ADDRESS]  
Polylactic acid thin films have significant potential as bioresorbable coatings.