In vivo label-free characterization of aged skin to predict delayed wound healing

项目概要： 创伤愈合的延迟归因于改变的真皮微观结构、线粒体和神经元的结构。 功能障碍和减少的细胞增殖。然而，无法非破坏性地测量这些 这些特性限制了它们在指导伤口护理和产品开发中的使用。的长期目标 该项目旨在建立非侵入性、实时、定量的光学生物标志物，以预测与年龄相关的延迟 在皮肤伤口愈合方面。这项建议的具体目标是利用无标记多光子显微镜 技术，包括双光子激发荧光，荧光寿命成像，和二次谐波 一代人，以识别和开发与衰老相关的皮肤的代谢和微观结构生物标志物， 延迟闭合和易受机械性再损伤。我们的核心假设是， 细胞及其周围基质的荧光可以被量化以提供灵敏的年龄生物标志物， 相关的伤口愈合障碍。为了验证这一假设并评估衰老的影响， 临床研究将使用年龄在其预期寿命的12.5-75%范围内的小鼠进行， 与常见的慢性伤口合并症如糖尿病无关。在目标1中，我们将不- 侵入性监测单个活小鼠中伤口愈合动力学并鉴定伤口代谢的差异 在愈合过程中使用天然荧光的NADH和FAD。目标2：量化 使用多光子显微镜预测创伤强度的细胞外基质组织和组成 通过基于图像的多尺度建模。在目标3中，我们将评估糖尿病对 目的1和2中开发的伤口愈合的年龄相关光学生物标志物。的定量比较 细胞和细胞外生物标志物将在不同年龄进行，并根据组织学进行验证， 免疫组化该项目的预期成果是一组候选生物标志物，用于 指导治疗，能够区分年龄相关的改变和常见的合并症， 损害愈合。随着多光子显微镜技术已经进入临床， 这里开发的方法有可能对临床评估和管理产生直接影响 伤口。

Project Summary: Age-related delays in wound healing have been attributed to altered dermal microstructure, mitochondrial dysfunction, and reduced cellular proliferation. However, an inability to non-destructively measure these characteristics has limited their use in guiding wound care and product development. The long-term goal of this project is to establish non-invasive, real-time, quantitative optical biomarkers to predict age-related delays in skin wound healing. The specific objective of this proposal is to utilize label-free multiphoton microscopy techniques, including two-photon excited fluorescence, fluorescence lifetime imaging, and second harmonic generation to identify and develop metabolic and microstructural biomarkers of aged skin that are associated with delayed closure and susceptibility to mechanical re-injury. Our central hypothesis is that the natural fluorescence of cells and their surrounding matrix can be quantified to provide sensitive biomarkers of age- related wound healing impairment. To test this hypothesis and evaluate the effect of aging, controlled pre- clinical studies will be performed using mice with ages ranging from 12.5-75% of their life expectancy, independent of common chronic wound comorbidities such as diabetes mellitus. In Aim 1, we will non- invasively monitor wound healing dynamics in individual live mice and identify differences in wound metabolism during the healing process using the natural fluorescence of NADH and FAD. In Aim 2, we quantify extracellular matrix organization and composition using multiphoton microscopy to predict wound strength through image-based multiscale modeling. In Aim 3, we will evaluate the effect of diabetes mellitus on the age-related optical biomarkers of wound healing developed in Aims 1 and 2. Quantitative comparisons of cellular and extracellular biomarkers will be made across different ages and validated against histology and immunohistochemistry. The expected outcome of this project is a set of candidate biomarkers for use in guiding therapy that are capable of discriminating age-related alterations and common comorbidities known to impair healing. With multiphoton microscopy technology already making its way into the clinic, the imaging methods developed here have the potential for immediate impacts in the clinical assessment and management of wounds.