Blood, guts and chemical engineering

Abstract

AbstractBasic chemical engineering sciences have been used to address selected medical problems. The natural anticoagulant, heparin, has been immobilized to a polyvinyl alcohol (PVA) coating on polyethylene or polyurethane, to prepare a blood compatible material. Modelling of the relationship between the rate of heparin leakage from the coating and the blood heparin concentration at the blood material interface supported the conclusion that the observed inhibition of clot formation induced by the material was due to the activity of the covalently immobilized heparin. The relationship between flow resistance and tube diameter was used to devise an ex vivo system for demonstrating this activity: 1 mm ID heparin‐PVA coated tubing was tested in a parallel flow circuit with a 3 mm ID silicone tubing so as to control the blood flow through the 1 mm test tubing. In another area of chemical engineering activity in biomedical sciences, live mammalian cells have been microencapsulated in a polymer membrane to prevent the host's antibodies, that are outside the capsule, from causing the immune destruction of the to‐be‐transplanted cells (e.g., pancreatic islets for the treatment of diabetes). These works illustrate the use of chemical engineering in nontraditional ways, consistent with what some consider the new “paradigm” for our profession.