This study aimed to synthesize methoxy polyethylene glycol propionaldehyde (mPEG20,000-ALD) for the preparation of PEGylated nanoliposomal cisplatin. Nanocarriers such as liposomes are developed for a wide range of drug delivery systems. PEG with high molecular weight (Mw) is used to coat the liposomes. In this study, simulated Fourier transform infrared (FTIR) spectra of mPEG-ALD were obtained using density functional theory (DFT) calculations and then compared with actual FTIR spectrum of mPEG20,000-ALD (Mw = 20 kDa). We found that the intensity of C = O stretching vibration at 1,700 cm-1 related to the carbonyl functional group of mPEG20,000-ALD was very weak. The results of DFT calculations of mPEG-ALD showed that by increasing the Mw of mPEG-ALD, the intensity of C = O stretching vibration related to the carbonyl functional group of mPEG-ALD was decreased, so we concluded the hypothesis of decreasing the intensity of C = O stretching vibration at 1,700 cm-1 as a result of increasing the Mw of mPEG-ALD. In vitro release of cisplatin showed that the percentages of released cisplatin from PEGylated nanoliposomal cisplatin and free cisplatin were determined to be 46 ± 2% and 97 ± 3% after 35 h, respectively. Cytotoxicity of free cisplatin and PEGylated nanoliposomal cisplatin was evaluated and related half-maximal inhibitory concentration on human ovarian cancer cell line A2780CP was obtained to be 76.6 ± 3.1 and 46.6 ± 2.3 μg/mL, respectively.

中文翻译：

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聚乙二醇尺寸在化学光谱，细胞毒性和聚乙二醇化纳米脂质体顺铂释放中的作用。

这项研究旨在合成甲氧基聚乙二醇丙醛（mPEG20,000-ALD）以制备聚乙二醇化的纳米脂质体顺铂。诸如脂质体的纳米载体被开发用于多种药物递送系统。具有高分子量（Mw）的PEG被用于包被脂质体。在这项研究中，使用密度泛函理论（DFT）计算获得了mPEG-ALD的模拟傅立叶变换红外（FTIR）光谱，然后与mPEG20,000-ALD的实际FTIR光谱（Mw = 20 kDa）进行了比较。我们发现，与mPEG20,000-ALD的羰基官能团有关的1,700 cm-1处C = O拉伸振动的强度非常弱。mPEG-ALD的DFT计算结果表明，通过增加mPEG-ALD的Mw，降低了与mPEG-ALD的羰基官能团相关的C = O拉伸振动的强度，因此我们得出这样的假设，即由于增加mPEG的Mw而降低了1,700 cm-1的C = O拉伸振动的强度-ALD。顺铂的体外释放表明，在35小时后，从聚乙二醇化的纳米脂质体顺铂和游离顺铂中释放出的顺铂百分比分别为46±2％和97±3％。评估了游离顺铂和聚乙二醇化的纳米脂质体顺铂的细胞毒性，对人卵巢癌细胞系A2780CP的相关半最大抑制浓度分别为76.6±3.1和46.6±2.3μg/ mL。增加mPEG-ALD的Mw的结果是700 cm-1。顺铂的体外释放表明，在35小时后，从PEG化的纳米脂质体顺铂和游离顺铂中释放的顺铂百分比分别为46±2％和97±3％。评估了游离顺铂和聚乙二醇化的纳米脂质体顺铂的细胞毒性，对人卵巢癌细胞系A2780CP的相关半最大抑制浓度分别为76.6±3.1和46.6±2.3μg/ mL。增加mPEG-ALD的Mw的结果是700 cm-1。顺铂的体外释放表明，在35小时后，从聚乙二醇化的纳米脂质体顺铂和游离顺铂中释放出的顺铂百分比分别为46±2％和97±3％。评估了游离顺铂和聚乙二醇化的纳米脂质体顺铂的细胞毒性，对人卵巢癌细胞系A2780CP的相关半最大抑制浓度分别为76.6±3.1和46.6±2.3μg/ mL。