Introduction An average adult has 5 L of blood Blood Red blood cells White blood cells Platelets Plasma Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Erythrocytes Red blood cells Disc-like bi-concave shape O2 and CO2 delivery Hemoglobin Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Hemoglobin Quaternary protein structure containing heme groups 1 RBC = 270 million Hb molecules 1 Hb molecule = 4 heme groups Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Fe Heme Group Porphyrin Ring Relaxed state Tensed state Fe ion becomes accessible to O2 as it is on the same plane Tensed state Fe ion becomes less accessible to O2 as it is pulled out of the plane Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

T vs. R state Conformational change Gas pressure driven Low O2 environment High O2 environment Conformational change Gas pressure driven Rotational of 15 degrees Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Perceived Clinical Problem Shortage of blood supply Blood types are a barrier to blood transfusion 4.9 million patients/year needs blood transfusion in the US Demand for blood > blood donations Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Respirocytes 1st nanomedical device-design technical paper: 1996 by Freitas Resembles RBCs Spherical w/ various diameter Aid medical treatments: Anemia Carbon monoxide poisoning Respiratory diseases Blood transfusion Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Respirocytes – Current Design Powered by glucose engines Gas exchange is selective -- via sorting rotors Made of sapphire or diamond (insulators) Various diameters from 0.2 to 100 microns Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Respirocytes – Design Issues Over-heating Radiation damage Interference with other blood components Biocompatibility Introduces unnecessary cell aggregation Over-pressure of gases Unpredictable robot life time Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Respirocytes – Alternative Design Utilize blood glucose as energy source Flat disc, mimics RBCs Diameter: 5 μm Thickness: 1 μm Central CPU Gas selective membrane (diffusion entrance) Sensor controlled valves Open/close valves for diffusion Selective rotors for releasing gas molecules Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Respirocytes – Alternative Design Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Respirocytes – Alternative Design Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Alternative Design – Flow Chart Sensor pCO2 > pO2 Release O2 Open CO2 membrane valve pO2 > pCO2 Release CO2 Open O2 membrane valve Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Ethical Issues Misuse of respirocytes for athletic purposes Alters the natural body state by introducing foreign objects Can create miniature bombs to kill bacteria – Can create weapons of mass destruction Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

Conclusion and Future Work Goal: universal blood source Purpose: To improve the quality of life of patients suffering from anemia, lung cancer, blood transfusions, and diseases that cause excess blood loss Problems associated w/cell aggregation & biocompatibility requires further investigation Introduction Respirocytes Ethical Issues Erythrocytes Proposed Design Conclusion & Future Work

References [1] Lin, S., “Medical Nanorobot: Constructing Biological Motor Powered Nanomechanical Devices,” Science in NanoMedicine & NanoMechanics. [2] “Nanotechnology, nanomedicine and nanosurgery,” International Journal of Surgery, 2005. [3] Breault, K. et al., “Nanomedicine,” California Engineer, vol. 82, pp. 9-14, spring 2004. [4] http://dev.nsta.org/evwebs/10955/page2.html [5] El-Sayed, S. et al., “Nanobiotechnology and its applications.” [6] http://www.nda.ox.ac.uk/wfsa/html/u10/u1003_01.htm