Early diagnosis of neonatal respiratory distress syndrome (nRDS) is important in reducing the mortality of preterm babies. Knowledge of the ratio of two components of lung surfactant, dipalmitoylphosphatidylcholine (DPPC), and sphingomyelin (SM) can be used as biomarkers of lung maturity and inform treatment. Raman spectroscopy is a powerful tool to analyze vibrational spectra of organic molecules which requires only limited sample preparation steps and, unlike IR spectroscopy, is not masked by water absorption. In this paper, we explore the potential of using Raman spectroscopy as a tool to estimate the ratio of DPPC and SM from aqueous vesicles of binary mixture of DPPC and SM. We demonstrate that the ratio of DPPC and SM can be estimated by estimating the ratio of intensity of CO stretch of DPPC and CC stretch of SM as well as CO stretch of DPPC and amide I of SM. Further, we employ a partial least squares regression (PLSR) model to automate the estimation and demonstrate that PLSR method can predict the DPPC and SM ratio with an R² value of 0.968.

中文翻译：

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使用拉曼光谱定量二元脂质体中肺表面活性剂脂质（二棕榈酰磷脂酰胆碱/鞘磷脂）比率

新生儿呼吸窘迫综合征（nRDS）的早期诊断对于降低早产儿死亡率非常重要。了解肺表面活性物质二棕榈酰磷脂酰胆碱 (DPPC) 和鞘磷脂 (SM) 两种成分的比例可用作肺成熟度的生物标志物并为治疗提供信息。拉曼光谱是分析有机分子振动光谱的强大工具，仅需要有限的样品制备步骤，并且与红外光谱不同，不会被水吸收掩盖。在本文中，我们探讨了使用拉曼光谱作为工具来估计 DPPC 和 SM 二元混合物的水囊泡中 DPPC 和 SM 的比率的潜力。我们证明，可以通过估计DPPC的C-O拉伸和SM的C-C拉伸以及DPPC的C-O拉伸和SM的酰胺I的强度比来估计DPPC和SM的比率。此外，我们采用偏最小二乘回归（PLSR）模型来自动估计，并证明PLSR方法可以预测DPPC和SM比率，R ²值为0.968。