생체모방 표면 개질을 이용한 조직공학용 나노섬유의 개발

Abstract

In tissue engineering, the surface property of substrates regulates a variety of cellular behaviors. Thus, the surface modification strategies have been used to improve cell-substrate interactions. In this study, we developed a simple bioinspired method to modify the surface characteristics of biocompatible and biodegradable nanofibers prepared from Poly(L-lactic acid) (PLLA). 3% (w/v) PLLA nanofibers were fabricated via electrospinning technique, and then immersed in aqueous dopamine solution with mild shaking for various times. SEM and AFM were used to analyze the morphology of the prepared nanofibers and the amount of coated dopamine was measured. XPS and ATR-FTIR were used to analyze the surface chemical property of the nanofibers and water contact angle was also measured. Mouse osteoblasts MC3T3-E1, human umbilical vein endothelial cell (HUVEC), and human mesenchymal stem cells (hMSCs) were cultured to investigate cell adhesion. After 12 hrs of culture, the cells grown on the nanofibers were observed by fluorescent counter staining for actin filament and nucleus. We confirmed that the efficiency of dopamine coating on the nanofibers increased as a function of coating time. The various surface characterization results showed the degree of coated dopamine on the nanofiber surface increased in its coating time dependent manner. Water contact angle analysis showed enhanced hydrophilicity of the surface as dopamine coating time increased on the nanofibers. In addition, the coated dopamine on the nanofibers affected cell attachment on the surface. The cells cultured on PLA nanofibers showed round shape with a condensed structure while the cells on the dopamine coated nanofibers showed spread and polygonal morphology. The number of cells attached on dopamine coated nanofibers was significantly greater than that on PLLA nanofibers. These results reveal that the bioinspired surface modification of synthetic materials by simple coating method can be potentially used as substrates to enhance cellular behavior.