Biomaterials for MEMS

Chapter Eight

Polymer-Based Biocompatible Surface

Coatings

Kai Yu, Guangzheng Gao and Jayachandran N. Kizhakkedathu

∗

Centre for Blood Research, Department of Pathology and Laboratory Medicine,

University of British Columbia, Vancouver, BC, V6T 1Z3, Canada

∗

E-mail: [e-mail]

8.1 INTRODUCTION

The performance of a material intended for biomedical applications depends on its

interfacial properties and reactions that occur when come in contact with biological

fluids. Non-specific protein adsorption at the biomaterial interface is the first

and critical event that initializes a cascade of host responses, including platelet

activation, blood coagulation, and complement activation.

1,2

Many approaches

have been used to prevent such non-specific interactions.

3−6

Coating or immobilization of surfaces with biomacromolecules such as

albumin

7−12

and anticoagulants like heparin

13−18

have been widely studied to-

wards this purpose. Another approach to overcome this problem is to coat the

surface with synthetic hydrophilic polymers

4,19

and this method has been used

as a anti-fouling treatment for a number of applications including biosensors

20

and drug delivery systems.

21

It was demonstrated that such coatings frequently

extend the life span of biomedical devices

22−23

and the circulation half life of drug

delivery systems.

24−25

Several factors that affect the protein-repelling properties of polymer thin films

on surface include the similarity of interfacial free energies of the polymer with

that of water, interaction of proteins with polymers through hydrophobic or charge

interactions and environmental factors such as temperature and pH.

26−28

In the

case of neutral hydrophilic polymer grafted surfaces, the steric barrier due to

high conformational entropy of anchored chains is one of the contributing factor

towards protein repulsion.

29−35

Other factors include, the structure of the polymer

Biomaterials for MEMS, Edited b y M. Chiao and J.-C. Chiao

Copyright © 2011 by Pan Stanford Publishing Pte. Ltd.

www.panstanford.com

978-981-4241-46-5

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