Nanomedicine-Based Targeting of Inflammatory Macrophages in Diabetic Wound Repair

摘要 糖尿病患者的伤口无法愈合是下肢截肢的主要原因， 美国的慢性、局部炎症被认为是糖尿病患者愈合缓慢的一个致病因素， 伤口和巨噬细胞被认为是这种炎症的主要介质。在非糖尿病患者中， 巨噬细胞最初在伤口中处于促炎状态， 促进组织修复的表型。在糖尿病患者中，炎性巨噬细胞表型持续存在， 导致血管生成、肉芽组织形成和愈合所需的伤口收缩的损害。 全身给药的抗炎或免疫调节药物不 在临床或临床前动物模型中改善愈合，事实上，可能由于关闭， 在其他免疫或结构细胞中的靶向作用，促进组织修复。该提案的重点是 开发基于靶向纳米材料的药物载体，以改变药物制剂的递送路线 在局部施用后，选择性地针对伤口中的炎性巨噬细胞，以消除脱靶效应。我们 特别关注于抑制产生炎性前列腺素的过度活跃的途径。在我们 初步数据，我们表明，多糖基纳米载体可以提供环氧合酶2抑制剂， 伤口巨噬细胞，以有效地减少炎性细胞因子的表达和加速伤口愈合， 糖尿病小鼠模型。该提案的目的1是优化制剂，使靶向药物的效率最大化。 使用荧光和放射性同位素标记的纳米载体递送至伤口中的炎性巨噬细胞， 通过核成像进行体内评价，通过流式细胞术、γ孔计数和荧光进行离体评价 显微镜目的2是优化靶向药物的治疗制剂的功效和药物释放速率。 前列腺素合成对糖尿病伤口愈合的不同调节途径。目标3：评估 在2型糖尿病的多种鼠急性和慢性伤口愈合模型中的疗效和脱靶效应， 以及来自糖尿病患者的单核细胞衍生的巨噬细胞。这项工作的基本成果将是 了解伤口中的纳米材料转运和靶向巨噬细胞的受体介导机制 亚群，以及对肾上腺素驱动的炎症过程在 糖尿病伤口中的巨噬细胞。纳米载体递送剂基于已经广泛应用的材料。 临床使用，如果临床前结果不符合要求， 很有希望这项工作将由一个由生物工程师组成的跨学科小组进行（安德鲁·史密斯 实验室），专注于纳米材料为基础的药物输送和成像剂，分子和细胞 免疫学和糖尿病伤口愈合机制（凯瑟琳加拉格尔实验室），以及核医学专家 成像和放射药理学（Wawrzyniec Dobrucki实验室）。

ABSTRACT The inability of wounds to heal in diabetic patients is the leading cause of lower extremity amputation in the United States. Chronic, localized inflammation is believed to be a causative factor in the slow healing of diabetic wounds, and macrophage cells are implicated as primary mediators of this inflammation. In non-diabetic patients, macrophages are initially in a pro-inflammatory state in wounds and shift over time to an anti-inflammatory phenotype that promotes tissue repair. In diabetic patients, the inflammatory macrophage phenotype persists, resulting in impairment of angiogenesis, granulation tissue formation, and wound contraction required for healing. Systemically administered pharmacological agents that are anti-inflammatory or immunomodulatory do not improve healing in the clinic or in preclinical animal models and, in fact, further impair healing, likely due to off- target effects in other immune or structural cells that facilitate tissue repair. This proposal focuses on the development of drug carriers based on targeted nanomaterials to reroute the delivery of pharmacological agents selectively to inflammatory macrophages in wounds after local administration to eliminate off-target effects. We are particularly focused on inhibiting overactive pathways that generate inflammatory prostaglandins. In our preliminary data, we show that polysaccharide-based nanocarriers can deliver cyclooxygenase 2 inhibitors to wound macrophages to potently diminish inflammatory cytokine expression and expedite wound healing in diabetic mouse models. Aim 1 of this proposal is to optimize formulations that maximize the efficiency of targeted delivery to inflammatory macrophages in wounds using fluorescent and radioisotopically labeled nanocarriers, evaluated in vivo by nuclear imaging and ex vivo by flow cytometry, gamma well counting, and fluorescence microscopy. Aim 2 is to optimize the efficacy and drug release rate of a therapeutic formulation that targets different regulatory pathways of prostaglandin synthesis toward diabetic wound healing. Aim 3 is to evaluate efficacy and off-target effects in multiple murine acute and chronic wound healing models of type 2 diabetes, as well as monocyte-derived macrophages from diabetic patients. Fundamental outcomes of this work will be an understanding of nanomaterial transport in wounds and receptor-mediated mechanisms to target macrophage subpopulations, as well as an understanding of the role of prostaglandin-driven inflammatory processes in macrophages within diabetic wounds. The nanocarrier delivery agents are based on materials already in broad clinical use, which may expedite clinical testing of the resulting therapeutic agents if preclinical results are promising. This work will be undertaken by an interdisciplinary team comprising bioengineers (Andrew Smith Lab) who focus on nanomaterial-based drug delivery and imaging agents, experts in molecular and cellular immunology and mechanisms of diabetic wound healing (Katherine Gallagher Lab), and experts in nuclear imaging and radiopharmacology (Wawrzyniec Dobrucki Lab).