Key Lab of Biorheological Science and Technology (Chongqing University);
Ministry of Education;
College of Bioengineering;
Chongqing University;
Chongqing 400030;
China;
Research Center of Bioinspired Material Science and Engineering;
College of Bioengineering;
Chongqing University;
Chongqing 400030;
China;
Department of Biology;
Chongqing University of Science and Technology;
Chongqing 401331;
China Received 29 June 2010;