Various types of transfection agents using nanoparticles have been researched to develop a drug for gene therapy. Recently, organo-phyllosilicates and its modified materials, known for properties like high water solubility and cationic electricity, have emerged as bio-applicable materials. First, we have investigated the cytotoxic assay of Fe-aminoclay (FeAC) nanoparticles (NPs) and simultaneous imaging in cells by photoluminescent carbon nanodots (CD) conjugation. As increase of CD-FeAC NPs loading in HeLa cell in vitro, it showed slight cytotoxicity at $1,000 \mu g/mL$ but no cytotoxicity for normal cells upto concentration of $1,000 \mu g/mL$ confirmed by various cytotoxicity assays, possessing that CD-FeAC NPs can be used as potential drug delivery platforms in cancer cells with simultaneous imaging. Second, we developed FeAC NPs gene carrier which is capable of gene delivery. Negatively charged DNA can be strongly grafted onto the terminal region of FeAC NPs. By employing FITC conjugated FeAC NPs in HeLa cells, we successfully detected fluorescent signals using confocal bioimaging and fluorescence spectroscopy, which confirmed the optimal condition for cellular uptake. In addition, DNA was delivered by FeAC NPs to HeLa cells and successfully expressed fluorescent protein. Gene transfection efficiency was optimized to N/P ratio of 5. Lately, we developed fluorinated FeAC NPs for cancer therapy with low toxic effects. In this study, inhibitor gene of apoptosis in cancer cell was knocked out by siRNA gene delivery using fluorinated FeAC NPs. FITC modified siRNA is combined with fluorinated FeAC NPs to demonstrate cellular uptake. The FITC-siRNA was successfully detected by confocal bioimaging. Binding affinity between siRNA and fluorinated FeAC NPs was optimized using agarose gel electrophoresis. Target gene was successfully suppressed by the delivered siRNA, and confirmed by RT-PCR. Therefore, we can conclude that gene delivery using aminoclay NPs provides a new possibility of developing organo-phyllosilicates into an effective drug for cancer therapy.
이 논문에서는 양이온성을 띄는 낮은 독성의 유기물질인 결합형 엽상 규산염류의 구조적 특성 및 세포 내 유전자 전달 가능성에 대해 다루었다. 먼저, 철 이온이 포함된 엽상 규산염류를 합성하여 다양한 분석법을 통해 물질의 구조적 특성을 확인하고, 다양한 독성평가를 통해 세포 내 무해성을 확인하였다. 다음으로 탄소 나노 입자와 플루오레세인이소티오시안산염 등의 형광물질 도입하여, 세포 내 흡수양상을 살펴보았다. 이후, 형광단백질 발현 유전자와 철 이온이 포함된 엽상 규산염류의 결합물을 세포에 처리하여, 유전자 전달 물질로써의 가능성을 형광 신호 검출을 통해 검증하였다. 추가로, 철 이온이 포함된 엽상 규산염류는 플루오린 결합을 통해 유전자 전달 효율이 증가되었고, 이를 이용하여 암세포 사멸 억제에 관여하는 짧은 간섭 리보핵산을 암세포에서 전달하였다. 그 결과, 암세포 사멸 억제에 관여하는 유전자가 제어되었다. 즉, 본 연구를 통해 새로운 물질의 암 치료 유전자 전달 가능성을 제시하였다.
