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

摘要(家长奖) 尽管尽了很大努力保持手术室无菌，但手术部位感染(SSI)仍然是一种严重和 顽固的问题，在美国每年导致多达8200名患者死亡。我们的长期目标是开发新的 有效地将SSI风险降至最低并促进伤口愈合的治疗方法。在前几个供资周期内 在这一奖项中，我们证明了i)维生素D和维生素D的成功包裹和持续释放 其他免疫调节化合物诱导较高的中草药抗菌肽(CAMP)基因和 人cAMP转基因细胞培养中免疫细胞和角质形成细胞中蛋白质(hCAP18/LL-37)的水平 小鼠创伤模型和人类皮肤移植；ii)局部应用维生素D增加对金黄色葡萄球菌的杀灭作用 在使用我们的人cAMP转基因小鼠的皮肤伤口感染模型中；以及iii)从 经维生素D处理的免疫细胞含有较高水平的hCAP18/LL-37。此外，我们还开发了一种 一种新型气体发泡膨胀技术，用于制备改进的3D纳米纤维支架，该支架可洗脱维生素D， 促进免疫细胞浸润，诱导hCAP18/IL-37，减轻炎症，促进 植入人类免疫系统的小鼠的新生血管和胶原沉积。建立在这些基础上 调查结果和我们的初步数据，我们建议的目标是开发基于纳米纤维的 增强天然免疫力的敷料。我们最重要的假设是，共同封装 3D纳米纤维支架中免疫细胞分泌外体的免疫调节化合物 是否会协同增强对SSI的保护，并比任何一种组件更好地促进伤口愈合 独自一人。要做到这一点，有三个具体的目标：1)展示有效的包封剂和洗脱剂 来自我们改进的3D纳米纤维支架的免疫调节化合物；2)测定抗菌和 来自预置或人cAMP转基因免疫细胞的外切体的伤口愈合效果；3) 展示免疫调节化合物和外切体共掺3D纳米纤维的有效性 在人源化转基因小鼠模型和体外实验中促进愈合和预防感染的支架 人体皮肤移植。在我们先前拨款工作的基础上，我们期待着成功地完成这一目标 更新将为开发下一代新型治疗性抗感染伤口奠定坚实基础 可以极大地加速愈合、降低SSI发生率并最大限度地减少抗生素的发展的敷料 抵抗。我们还希望这些敷料可以作为创伤和战斗的有效治疗方法。 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.