传感器类型
综述或非传感器论文
检测对象
无明确被测物;细胞图案化对象:293T人胚胎肾细胞(293T cells),样品基质:DMEM培养基(含2%胎牛血清)
检测原理
本文并非分析物浓度响应型传感检测,其核心是表面化学差异诱导的细胞图案化。HFBI为两亲性疏水蛋白II,在疏水PDMS表面自组装时,疏水β-片层锚定于PDMS,亲水α-螺旋外露,使水接触角由117°降至56.3°,从而促进胶原固定。胶原涂覆后提供细胞粘附位点,水接触角变为92°。铜TEM网格作为掩膜限域HFBI/胶原修饰区域,形成椭圆图案;原生PDMS在低血清条件下抑制细胞粘附,细胞仅在HFBI/胶原区域生长。转染PEI/pEGFP-C2后,细胞表达GFP,用于验证图案化细胞的生物活性。
检测灵敏度
原文未报告LOD、线性范围、灵敏度斜率及相关系数。
效应效果
XPS显示HFBI修饰后N 1s由0%升至5.8%,Si 2p由22.3%降至13.48%,证明HFBI覆盖PDMS;胶原修饰后表面组成变化不大。水接触角由原生PDMS的117°降至HFBI修饰后的56.3°,胶原修饰后为92°。在含2%胎牛血清的DMEM中培养16 h,HFBI/胶原修饰表面细胞接近100%汇合,而原生PDMS表面细胞粘附差、数量少。细胞图案可稳定限制至少4天,拥挤时发生凋亡。PEI/pEGFP-C2基因转染后观察到明显GFP荧光,表明图案化细胞生物活性良好。作者认为该方法可用于细胞迁移、神经发育、肿瘤生长等生物传感器器件研究。
传感器的构成
- 基底:PDMS(Sylgard 184)弹性体,疏水表面,抑制细胞粘附与生长
- 掩膜:铜TEM网格,压印形成椭圆图案区域
- 亲水化修饰层:HFBI(疏水蛋白II)自组装,将PDMS由疏水转为亲水
- 细胞粘附层:I型胶原(rat-tail type I collagen)涂覆于HFBI区域,支持细胞粘附与生长
- 细胞图案层:293T人胚胎肾细胞,在HFBI/胶原区域生长形成图案
- 生物活性验证层:PEI与质粒DNA pEGFP-C2,用于基因转染和GFP表达检测
中文摘要
在聚二甲基硅氧烷(PDMS)表面实现可控细胞生长对其在生物器件中的应用具有重要意义。本文报道了一种全生物相容的细胞图案化方法,通过疏水蛋白HFBI和胶原修饰PDMS表面,并利用铜TEM网格作为掩膜依次固定HFBI和胶原。HFBI在PDMS表面自组装后,可将原本疏水的PDMS表面转变为亲水表面,从而促进后续胶原的固定;胶原具有良好的支持细胞粘附与生长的能力。因此,HFBI/胶原修饰的PDMS表面能够促进细胞粘附与生长,而未经修饰的原生PDMS表面则不支持细胞粘附与生长。通过在HFBI/胶原图案化PDMS表面直接培养293T人胚胎肾细胞,实现了与铜网格图案相对应的细胞图案化。体外基因转染实验表明,图案化细胞仍具有良好的生物活性。该生物相容的细胞图案制备方法有望应用于生物传感器器件制造。
英文摘要
Controllable cell growth on poly(dimethylsiloxzne) (PDMS) surface is important for its potential applications in biodevices. Herein, we developed a fully biocompatible approach for patterning of cells on the PDMS surface by hydrophobin (HFBI) and collagen modification. HFBI and collagen were immobilized on the PDMS surface one after another by using copper grids as a mask. HFBI self-assembly on PDMS surface converted the PDMS surface from hydrophobic to hydrophilic, which facilitated the following immobilization of collagen. Collagen had admirable ability to support cell adhesion and growth. Consequently, the HFBI/collagen-modified PDMS surface could promote cell adhesion and growth. What is more, the native PDMS surface did not support cell adhesion and growth. Patterning of cells was achieved by directly culturing 293T cells (the human embryonic kidney cell line) on the PDMS surface patterned with HFBI/collagen. Further studies by means of gene transfection experiment in vitro showed that the patterned cells were of good bioactivities. Herein, the biocompatible preparation of cell patterns on the PDMS surface could be of many applications in biosensor device fabrication.