Biocompatibility of Novel Bactericidal Polymers
Bradley Allison and Jeffrey Youngblood

Quaternized poly (vinylpyridine) (PVP) is a known anti-bacterial material.  However, PVP has a limitation, low biocompatibility, which prevents it from being used in many applications.  By copolymerizing PVP with biocompatible monomer, we hope to retain the anti-bacterial properties and enhance biocompatibility to work in conjunction with the human body. 

Biocompatibility of bactericidal polymers is one research focus which will help understand the feasibility and limitations of our materials in contact with the human body.  Many biomaterials currently used in contact with the body are composed of materials not originally designed to work with the body. Instead of working with the body, many materials are seen as foreign bodies which can invoke an immune response. Understanding interactions of materials with the body is a key to creating new desired reactions in the body with synergistic results. Blood hemolysis and protein adsorption are the initial biocompatibility tests we are using to analyze cell interaction with our materials.

Blood hemolysis is a basic cytotoxicity (cell killing) test to see the interactions of a material with red blood cells (RBC).  RBCs have a limited lifetime before they are recycled by the body.  However, foreign materials and excessive stress can cause RBCs to rupture and release excessive hemoglobin (the oxygen carrier in RBCs) in the blood stream.  This test shows the sensitivity of cells by measuring the hemoglobin released during interaction with a foreign material.

The body contains many different proteins, which control the reaction the body has to a foreign material.  By testing protein adsorption to a material, the resulting reaction the body can be better understood in an in vitro setting (outside of the body).  Understand how the body will reply to our material will allow us to further develop materials that can eventually be used advantageously in bio applications.


Red blood cell hemolysis in polymer solutions increasing
right as a function of polymer composition.