The characteristics of cultured cell attachment onto poly-l-lysine (PLL), collagen, and the thermoresponsive polymer poly(N-isopropylacrylamide) (PNIPAM) were studied using a quartz crystal microbalance (QCM). A QCM with microscope cameras enclosed in a Peltier chamber was developed to enable QCM measurements and microphotographic imaging to be conducted in a temperature-controlled CO₂ incubator. Human hepatoma cell line HepG2 cells were cultured on the quartz crystals coated with PLL, collagen, and PNIPAM. Response curves of the resonant frequency of the quartz crystals during the cell attachment process were analyzed on the basis of the parameters of modeling curves fit to the experimentally obtained curves. Analysis of the fitting curves showed that the time constants of the first-lag response were 11 h for PLL, 16 h for collagen, and 38 h for PNIPAM and that the frequency change for the PNIPAM films was six times smaller than those for the PLL and collagen films. These findings were supported by photographic images showing wider cell spread on PLL and collagen than on PNIPAM. The response of cells on PNIPAM was measured during a thermal cycle from 37 to 20 °C to 37 °C. In the resonance frequency–resonance resistance (F–R) diagram, the slopes of ΔR/ΔF corresponding to the cell attachment process and those corresponding to the thermal cycling process differed; the positions in the F–R diagram also shifted to higher resonant frequencies after the thermal cycle. These results suggested that the mass effect decreased as a result of the weakening of the cell attachment strength by the thermal cycle because the molecular brushes of PNIPAM were disarranged.

使用石英晶体微量天平 (QCM) 研究了培养的细胞附着在聚赖氨酸 (PLL)、胶原蛋白和热响应性聚合物聚 ( N-异丙基丙烯酰胺) (PNIPAM) 上的特性。开发了一种带有封闭在 Peltier 室中的显微镜相机的 QCM，以使 QCM 测量和显微摄影成像能够在温度受控的 CO _2中进行孵化器。在涂有 PLL、胶原蛋白和 PNIPAM 的石英晶体上培养人肝癌细胞系 HepG2 细胞。在模型曲线参数与实验曲线拟合的基础上，分析了石英晶体在细胞贴壁过程中的共振频率响应曲线。拟合曲线分析表明，PLL 的第一滞后响应时间常数为 11 h，胶原蛋白为 16 h，PNIPAM 为 38 h，PNIPAM 薄膜的频率变化是 PLL 的 6 倍。和胶原蛋白膜。这些发现得到了照片图像的支持，照片显示 PLL 和胶原蛋白上的细胞分布比 PNIPAM 上更广。在 37 至 20 °C 至 37 °C 的热循环期间测量细胞对 PNIPAM 的响应。在谐振频率-谐振电阻（F - R ) 图，ΔR /ΔF 的斜率对应于细胞附着过程和对应于热循环过程的斜率不同；在热循环之后， F - R图中的位置也转移到了更高的谐振频率。这些结果表明，由于 PNIPAM 的分子刷杂乱无章，热循环削弱了细胞附着强度，导致质量效应降低。