Nanomedicine-Based Targeting of Inflammatory Macrophages in Diabetic Wound Repair

摘要 糖尿病患者的伤口不能愈合是糖尿病患者截肢的主要原因 美国。慢性局部炎症被认为是糖尿病愈合缓慢的原因之一。 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，并随着时间的推移转变为抗炎状态 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， 导致愈合所需的血管生成、肉芽组织形成和伤口收缩的障碍。 全身给药的抗炎或免疫调节药剂不起作用 在临床或临床前动物模型中促进愈合，事实上，可能是由于关闭- 靶向作用于促进组织修复的其他免疫或结构细胞。这项提案的重点是 基于靶向纳米材料的药物载体的研究进展 局部给药后，选择性地对创面中的炎性巨噬细胞进行作用，以消除非靶点效应。我们 尤其专注于抑制产生炎性前列腺素的过度活动途径。在我们的 初步数据表明，基于多糖的纳米载体可以将环氧合酶2抑制剂输送到 创伤巨噬细胞有效减少炎性细胞因子表达并加速创面愈合 糖尿病小鼠模型。这项建议的目标1是优化配方，最大限度地提高靶向 使用荧光和放射性同位素标记的纳米载体向伤口中的炎性巨噬细胞传递， 体内评价采用核成像，体外评价采用流式细胞术、伽玛计数和荧光法。 显微镜。目标2是优化靶向的治疗配方的疗效和药物释放速率 前列腺素合成对糖尿病创面愈合的不同调控途径。目标3是评估 多种小鼠急性和慢性2型糖尿病创面愈合模型的疗效和非靶点效应 以及糖尿病患者的单核细胞来源的巨噬细胞。这项工作的基本成果将是 了解纳米材料在伤口中的传输和受体介导的靶向巨噬细胞的机制 亚群，以及对前列腺素驱动的炎症过程在 糖尿病伤口内的巨噬细胞。纳米载体递送剂是基于已经广泛使用的材料 临床应用，这可能会加快最终治疗剂的临床测试，如果临床前结果是 很有希望。这项工作将由一个由生物工程师组成的跨学科团队承担(安德鲁·史密斯 实验室)专注于基于纳米材料的药物输送和显像剂，分子和细胞专家 糖尿病伤口愈合的免疫学和机制(凯瑟琳·加拉格尔实验室)，核专家 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).