1. Leandro Forciniti, Jose Ybarra III, John Maldonado, Muhammad H. Zaman, Christine E. Schmidt Chemical Engineering Doctoral Candidate, University of Texas, Austin

3.  Easy to injure  Trauma  Incident rate 2.4 % of the U.S. population  Expected to grow to 8.3% of the population due to an aging 1  War  35% troops extremities wounded in combat 2 1 Gale Encyclopedia of Neurological Disorders 2 Journal of Craniofacial Surgery. 21(4):998-1001, July 2010.

4. Fourth Degree Fifth Degree Injuries Requiring Treatment Peripheral Nerve Axon Endoneurium where Schwann cells are Perineurium Epineurium Third DegreeSecond DegreeFirst Degree Injuries That Autologously Recover

6. Chemical Contact Electrical Lee et al. (2002) Gomez et al. (2006) Huang et al. (2008) For more information on stimuli integration see Forciniti et al. ABME. (2008).

7. Electrical Stimulation (Estim) of PC-12 1 Nerve Growth Factor (NGF)-Stim of PC-12 2 Controllable Topology 3 1 Schmidt, C.E. et al. PNAS. 1997; 2 Lee, J.Y. et al. J.R. Soc. Interface 2009; 3 Ateh, D.D. et al. J.R. Soc. Interface. 2006. - + - +

8. Chemical Synthesis Electrochemical Synthesis

9. Forciniti et al. Biomedical Materials. 2008.

11. Forciniti et al. Biomedical Materials. (2008).

12. Copper tape Petri Dish Film Fibronectin (FN), Laminin (LN) or Nerve Growth Factor (NGF) PDMS Glue Petri Dish Cell Culture Media Film 10,000 SC 10 X Magnification Phase Contrast 10 min/frame From Counter and Reference Electrode socket (cathode) Cell Culture Media Film 10,000 SC 10 X Magnification Phase Contrast 10 min/frame e-e- From Working electrode socket (anode)

13. 0.1 V + 10% FBS Electric Field seen in media ~ 80 mV @ 2 mm distance from surface Indium Tin Oxide (ITO) PPy:PSS on ITO 300-600 Å 1,090 Å

15. PPy:PSS No proteinPPy:PSS 100 ug/mL LN PPy:PSS 100 ug/mL LN + Estim

16. PPy:PSS + 100 ng/mL NGF (18 hours) PPy:PSS + 100 ng/mL NGF + Estim (18 hours) W.E.

17. a b c c a b c d Number of * denotes statistically similarity (p<0.05) a a a a b b b b

18. NGF FN LN Anode Cathode Top Bottom Center

19. a b b c c a

20. a,b a a c d b

21. a b a b c b

22. PPy:PSS Pre-stimulation PPy:PSS Post-stimulation

23.  Electrical stimulation affects only the directionality of the migration rather than cell migration speed.  Adsorption levels of stimulatory proteins affect cell migration speed.  Adsorption level and changes in surface topology may affect secretion levels of NGF by Schwann cells.

24.  We would like to determine ion flux passing by the cell upon electrical stimulation. We propose to monitor the flux of a charged dye upon electrical stimulation.  We would like to determine the effect increase protein adsorption upon electrical stimulation has on surface topology. We propose to get AFM roughness data.  We would like to determine whether electrical stimulation is reversible. We propose to monitor cell migration upon reversible electrical gradients.

25.  Dr. Christine E. Schmidt  Dr. Muhammad H. Zaman  Dr. Schmidt’s Lab  Dr. Zaman’s Lab  Zin Khaing  Jae Y. Lee  Funding Resources: ▪UT Graduate Continuing Fellowship ▪NIH R21

26. Questions?

27. PPy:PSS + 100 ng/mL NGF Adhesion (2 hours) PPy:PSS + 100 ng/mL NGF + 1 V Migration (18 hours) W.E.