Such organic polymers or coatings can be selected from a wide array of polymeric materials including, but not limited to, carbohydrates such as dextran (preferably having a molecular weight between 5,000 and 250,000 daltons), proteins (preferably having a molecular weight between 5,000 and 250,000 daltons) such as bovine or human serun albumin, polpeptides (preferably having molecular weights betw