Effect of Bombyx mori's Sericin Immobilization over Poly (L-Lactic Acid) Surface on Mesenchymal Stem Cells Attachment and Proliferation

Poly(L-lactic acid) or PLLA as one of tissue engineering material have demonstrated low cell interaction capability due to its hydrophobicity. Bombyx mori's sericin, a polymer protein that has strongly polar side groups such as hydroxyl, carboxyl and amino groups, have been known to accelerate cells attachment and proliferation. The aim of this study was to investigate the effect of Bombyx mori's sericin immobilization with different concentration over PLLA surface on attachment and proliferation of mesenchymal stem cells (MSCs). Three concentration of sericin (2.5, 5, and 10 mg/ml) were applied on PLLA surface modification using carbodiimide chemistry. Surface characterization using Fourier Transform-Infrared Spectroscopy (FTIR) and water contact angle was performed to observe the changes on surface-modified PLLA. The MSCs attachment after 4 hours in culture and proliferation rate in 2 days were determined using hemocytometer. FTIR graphs showed that sericin was succesfully immobilized on PLLA surface. Contact angle measurement showed significant increases of the hydrophilicity on sericin-modified PLLA surfaces. MSCs attached to sericin-modified PLLA was higher in number than the cell attached on control PLLA (p<;0.05), but there was no difference between the treatment groups(p>0.05). However, the proliferation rate of sericin-modified PLLA has no significant differences with control PLLA (p>0.05). The conclusion was Bombyx mori's sericin application over PLLA surface enhanced MSCs attachment, but did not enhanced their proliferation rate.