Nanofiber-based Delivery of Combined Immune-modulating Compounds to Minimize Infection and Enhance Wound Healing

摘要（家长奖） 尽管努力保持手术室无菌，手术部位感染（SSI）仍然是一个严重的， 这是一个顽固的问题，在美国每年有8,200名患者死亡。我们的长期目标是开发新的 有效降低SSI风险并促进伤口愈合的治疗。在前几个供资周期 我们已经证明，i）成功地封装和持续释放维生素D， 其它免疫调节化合物诱导更高的凯萨林菌素抗菌肽（CAMP）基因， 细胞培养物中免疫细胞和角质形成细胞中的hCAP 18/LL-37蛋白水平，人CAMP转基因 小鼠伤口模型和人皮肤外植体; ii）局部维生素D增加对金黄色葡萄球菌的杀灭 在使用我们的人CAMP转基因小鼠的皮肤伤口感染模型中;和iii）由人CAMP转基因小鼠分泌的外泌体。 用维生素D处理的免疫细胞含有更高水平的hCAP 18/LL-37。此外，我们还开发了一个 一种新型的气体发泡膨胀技术，用于制造洗脱维生素D的改进的3D支架， 促进免疫细胞浸润，诱导hCAP 18/LL-37，减少炎症，并促进免疫细胞浸润。 新血管形成和胶原沉积。根据这些 研究结果，以及我们的初步数据，我们的建议的目标集中在纳米纤维为基础的发展 用于增强先天免疫的敷料。我们的首要假设是， 在3D支架中具有从经处理的免疫细胞分泌的外来体的免疫调节化合物 将协同增强对SSI的保护，并比任一组分更好地促进伤口愈合 一个人为了实现这一点，有三个具体的目标：1）证明有效的包封和洗脱， 免疫调节化合物从我们的改进的三维支架; 2）确定抗微生物和 来源于引发的或人CAMP转染的免疫细胞的外来体的伤口愈合功效;和3） 证明免疫调节化合物和外泌体的功效-共掺入3D微球 在我们的人源化转基因小鼠模型和离体模型中， 人体皮肤移植在我们先前赠款工作的基础上，我们希望成功完成本项目的目标。 更新将为开发下一代新型治疗性抗感染伤口奠定坚实的基础 敷料可以大大加快愈合，降低SSI的发生率，并最大限度地减少抗生素的产生 阻力我们还希望这些敷料可以作为有效的治疗创伤和战斗 相关伤害。

Abstract (Parent Award) Despite major efforts to keep operating rooms sterile, surgical site infections (SSIs) remain a serious and stubborn problem, killing up to 8,200 patients a year in the U.S. Our long-term goal is to develop novel therapies that effectively minimize risk of SSIs and promote wound healing. During the previous funding cycles of this award, we have demonstrated that i) successful encapsulation and sustained release of vitamin D and other immuno-modulating compounds induced higher cathelicidin antimicrobial peptide (CAMP) gene and protein (hCAP18/LL-37) levels in immune cells and keratinocytes in cell culture, a human CAMP transgenic mouse wound model and human skin explants; ii) topical vitamin D increased killing of Staphylococcus aureus in a skin wound-infection model using our human CAMP transgenic mouse; and iii) exosomes secreted from immune cells treated with vitamin D contained higher levels of hCAP18/LL-37. Furthermore, we developed a novel gas-foaming expansion technique to fabricate improved 3D nanofiber scaffolds eluting vitamin D that promoted immune cell infiltration, induced hCAP18/LL-37, decreased inflammation, and promoted neovascularization and collagen deposition in human immune system-engrafted mice. Building on these findings, and our preliminary data, the goal of our proposal focuses on the development of nanofiber-based dressings for enhancing innate immunity. Our overarching hypothesis is that co-encapsulating immunomodulating compounds with exosomes secreted from treated immune cells in 3D nanofiber scaffolds will synergistically enhance protection against SSIs and promote wound healing better than either component alone. To accomplish this, there are three specific aims: 1) Demonstrate efficient encapsulation and elution of immunomodulating compounds from our improved 3D nanofiber scaffolds; 2) Determine the antimicrobial and wound-healing efficacy of exosomes derived from primed or human CAMP transfected immune cells; and 3) Demonstrate the efficacy of immunomodulating compounds and exosomes- co-incorporated 3D nanofiber scaffolds to promote healing and prevent infection in our humanized transgenic mouse model and ex vivo human skin explants. Building on work from our prior grant, we expect successful completion of the aims in this renewal will lay a strong foundation for developing the next generation of novel therapeutic anti-infective wound dressings that could greatly speed healing, reduce rates of SSIs and minimize development of antibiotic resistance. We also expect these dressings could serve as effective treatments for traumatic and combat related injuries.