Background: Endothelial cells (EC) that make up the inner wall of blood vessels play an important role in angiogenesis and vascular recovery. Cardiovascular disease caused by dysfunction of ECs has been reported as a major cause of death worldwide. Despite significant research so far, the underlying mechanism of dysfunction of ECs in cardiovascular disease progression is not yet fully understood. Although therapeutic transplantation of autologous ECs is limited due to lack of cell availability, adiposederived stem cells (ADSCs), known for their ease of procurement and high potential for differentiation, will provide promising solutions to generate autologous ECs. Methods: This study investigated the optimal differentiation of ADSCs into ECs under EBM-2 culture conditions supplemented with VEGF and BMP-4 in hypoxia (2% O2). Results: During 14 days of in vitro differentiation, cells cultured in EBM-2 supplemented with VEGF showed the characteristics of early vascular ECs and some cells adopted polygonal forms. Conversely, cells cultured in EBM-2 and hypoxia supplemented with both VEGF and BMP-4 differentiated into the typical cobblestone morphology that appears in vascular ECs. As a result of immunostaining against the vascular ECs marker CD-31, CD-31 expression was increased under EBM-2 culture conditions with VEGF and VEGF + BMP-4 in hypoxia, but expression was insufficient in normal oxygenation (21% O2). In the flow cytometry analysis, high expression of CD-31 expression was observed under conditions including both VEGF and BMP-4 of hypoxia. Interestingly, in gene expression, the pluripotency marker OCT-3/4 was significantly reduced under hypoxic conditions, but SOX2 and NANOG expression were higher than under normal oxygen conditions. However, CD-31 expression was significantly higher under differentiation conditions in which VEGF and BMP-4 were added under hypoxia conditions. In a functional analysis, CD-31-positive ADSC-derived ECs differentiated under hypoxia had excellent tube formation and Dil-Ac-LDL uptake, which are important for vascular repair and function. Conclusions: These findings confirmed the therapeutic usefulness of ECs derived from ADSC for the treatment of cardiovascular disease due to the synergy effect of hypoxia and BMP-4.

목적 : 본 연구는 Polydimethylsiloxane(PDMS)를 기반으로 다양한 첨가제를 사용하여 고 기능성 안 의료용 고분자를 제조한 후, 제조된 렌즈 표면에 생체적합성 및 습윤성이 우수한 collagen을 코팅하여 물성을 비교 분석 하였다. 방법 : 렌즈 제조를 위해 PDMS와 친수성 모노머인 N,N-dimethylacrylamide(DMA), 2-Hydroxyethyl methacrylate(HEMA)를 주재료로 사용하였으며, 교차결합제인 Ethylene glycol dimethacrylate(EGDMA)와 열 개시제인 Azobisisobutyronitrile(AIBN)을 사용하였다. 또한 기능성 첨가제로는 1,3-Bis(3-aminopropyl) tetramethyldisiloxane(TMDS), Polyvinylpyrrolidone(PVP), 2-(Trifluoromethyl)styrene 및 collagen을 사 용하였다. 제조된 렌즈의 물성 평가를 위해 광투과율, 굴절률, 함수율, 산소투과율 그리고 인장강도를 각각 측정하였으 며, 접촉각 측정을 통해 습윤성을 평가하였다. 결과 : TMDS의 첨가비율에 따라 렌즈의 산소투과율은 약 28~45 ×10⁻¹¹(cm²/sec)(mlO²/ml×mmHg)으로 나타내었으며, PVP 및 2-(Trifluoromethyl)styrene가 첨가된 렌즈의 습윤성 및 인장강도는 56~46° 그리고 0.11~0.17 kgf/mm² 의 범위로 각각 나타났다. 다양한 첨가제를 사용함으로써 제조된 렌즈의 기능성이 향상되었 으며, 특히 콜라겐 첨가제의 사용은 하이드로겔 표면의 접촉각을 매우 감소시켜 우수한 습윤성을 가지는 것으로 나타났다. 결론 : TMDS, PVP 그리고 2-(Trifluoromethyl)styrene은 실리콘 하이드로겔 렌즈의 기능성 향상에 효과적 이며, 첨가제로서의 collagen 사용은 렌즈의 습윤성을 향상시키는 것으로 나타나 본 연구에서 사용된 재료는 안의 료용으로 다양하게 활용될 수 있을 것으로 판단된다.