Controlled-release of GDF-5 from micro-fibrous PLLA scaffold enhances osteogenic differentiation of human adipose-derived stem cells

Abstract

지방유래 줄기세포는 다분화능이 있고, 비교적 쉽게 골아세포로 분화 유도되므로 조직공학 연구자들의 관심을 받고 있다. 이러한 다분화능의 지방유래 줄기세포와 골분화 촉진 인자인, GDF-5를 조절방출하는 마크로 섬유형 폴리락타이드 지지체를 조합시켜, 지방유래 줄기세포의 골분화 촉진을 도모하였다. 습식방사 (wet-spinning) 법으로 세 종류의 지지체 (GDF-5와 1,25-dihydroxyvitamin D3 혼합 군, 1,25-dihydroxyvitamin D3 단일 군, 골분화 인자 배제 군)를 제작했고, 지방유래 줄기세포가 그 위에 배양되었다. 골분화 인자를 포함하지 않는 군에서 세포 증식 속도가 가장 빠르게 나타났으나, 세포 외 기질 미네랄화는 거의 일어나지 않았다. GDF-5와 1,25-dihydroxyvitamin D3 혼합 군에서는 ALPase 활성, 골아세포 관련 유전자발현, 세포 외 기질 미네랄화에서 다른 군들에 비해 높은 값을 보였다. 따라서 마크로 섬유형 폴리락타이드 지지체로부터의 GDF-5 조절방출이 1,25-dihydroxyvitamin D3와의 상승작용을 통해 지방유래 줄기세포의 골분화 유도를 촉진시킴을 알았다.;Human adipose-derived stem cells (hASCs) are considered to have multipotency and easily induced to differentiate into osteoblast, so hASCs are interesting material to many researchers who study tissue engineering. Combination of multipotent hASCs and scaffolds having ability in controlled release of osteogenesis related factors was planned in this study. Growth and differentiation factor-5 (GDF-5) is an appealing candidate for potentiating osteogenic differentiation. 1,25-dihydroxyvitamin D3 also plays an important role in osteogenic induction, so it was expected that controlled-release of GDF-5 from micro-fibrous poly(L-lactic acid)(PLLA) scaffold might enhance osteogenic differentiation of hASCs through synergistic effect between GDF-5 and 1,25-dihydroxyvitamin D3. Three kinds of scaffold (GDF-5 & 1,25-dihydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and no osteogenic factor) were fabricated by wet-spinning method and then hASCs were cultured on the fabricated scaffolds with ODM-like medium containing ascorbic acid and β-glycerophosphate. Osteogenic factor unloaded group showed the highest cell proliferation rate, whereas it had little ECM mineralization. GDF-5 & 1,25-dihydroxyvitamin D3 loaded group achieved the best result in alkaline phosphatase activity, osteogenic marker gene expression and ECM mineralization. This study suggested that controlled-release of GDF-5 with 1,25-dihydroxyvitamin D3 might potentially enhance osteogenic differentiation of hASCs.