“…As a unique cationic polysaccharide, chitosan has outstanding biocompatibility, bioadhesion, and biodegradability. There are many methods of introducing chitosan onto synthesized polymers such as alkaline hydrolysis followed by grafting-coating (Lao, Tan, Wang, & Gao, 2008;Sahoo, Sasmal, Nanda, Phani, & Nayak, 2010), layer-by-layer assembly (Zhu, Gao, He, Liu, & Shen, 2003), photo-initiated grafting (Zhu, Zhao, & Ma, 2009), and blending (Cooper, Bhattarai, & Zhang, 2011;Sundaramurthi, Vasanthan, Kuppan, Krishnan, & Sethuraman, 2012). Besides these methods, freeze-drying chitosan solution could also introduce chitosan to the scaffolds (Zhao, Han, Chen, et al, 2012a).…”