Nanofiber topographical and biochemical cues to be studied in this proposal. SEM images show a series of nanofibers prepared with different diameters.

We have developed methods to electrospin a wide range of biocompatible polymeric fibers (biodegradable and non-biodegradable) with controlled diameters (~150 nm to 2 µm) and alignments (aligned and randomly oriented).  In order to present the relevant biochemical cues from fiber surfaces, we have developed a surface grafting method to introduce various functional groups in a concentration range of 0.1 to 200 nmol/cm2 without compromising fiber integrity.

We are in the process of developing a versatile and robust scheme for surface conjugation of biochemical cues pertinent to stem cell adhesion, proliferation and differentiation, for example, key adhesion molecules (laminin and/or fibronectin) and growth factor (fibroblast growth factor-2, FGF-2).  We are interested to investigate how surface presentation of signaling molecules influences the signaling activation and stem cell proliferation and differentiation.

Publications

1. Lim SH, Mao HQ. Electrospun scaffolds for stem cell engineering. Adv. Drug Deliv. Rev. 61(12): 1084-1096 (2009).
2. Lin K, Chua KN, Christopherson GT, Lim S and Mao HQ, Reducing electrospun nanofiber diameter and variability using cationic amphiphiles. Polymer. 48: 6384-6394 (2007).
3. Christopherson GT, Song H, Mao HQ. The influence of fiber diameter of electrospun substrates on neural stem cell differentiation and proliferation. Biomaterials. 30(4): 556-564 (2009).
4. Chua KN, Lim WS, Zhang P, Lu H, Wen J, Ramakrishna S, Leong KW, and Mao HQ. Stable immobilization of rat hepatocyte spheroids on galactosylated nanofiber scaffold. Biomaterials. 26(15): 2537-2547 (2005).
5. Chua KN, Tang YN, Quek CH, Ramakrishna S, Leong KW, and Mao HQ. A dual-functional fibrous scaffold enhances P450 activity of cultured primary rat hepatocytes. Acta Biomater. (2007).