Functionalization of LbL-Microcarriers as Drug Delivery System for Elastase Inhibitors and HOCl Scavengers for the Termination of Chronic Inflammation

慢性炎症的治疗在现代世界是一个重要的医学挑战。全身作用药物的应用往往伴随着多种副作用。因此，开发新的药物传递系统必须考虑药物的靶向和局部持续应用，具有高效和减少副作用的特点。层层包覆的微载体是治疗局部炎症的极佳选择，例如关节炎症。模块化的构建原理，即相反电荷的聚电解质逐步吸附到球形微模板上，形成多层活性物质集成，具有许多优点：使用生物相容和可生物降解的聚合物，一种或多种活性物质的时间可控和持续释放，特定的细胞靶向和高生物相容性。这项建议的主题是继续对这些特定载体的概念开发和研究，这些载体涉及抗炎物质向炎症组织的运输。在这里，中性粒细胞是研究的重点：这些免疫细胞持续产生相当数量的侵略性酶，有助于时代化和大规模的组织破坏。一种特殊的酶，弹性蛋白酶，在这些过程中发挥着重要作用。为了有效地抑制弹性蛋白酶，LBL微载体将被设计成通过一种途径来促进抗胰蛋白酶(AT)对细胞内和细胞外弹性蛋白酶的抑制。此外，LBL微载体的模块化结构将被用来提供不止一种活性物质，但具有不同的释放动力学：中性粒细胞也释放活性氧物种(ROS)以及导致AT活性丧失的HOCl。因此，HOCl清除剂头孢哌酮将被整合到多层膜中以保持AT活性。在这项建议中，将研究两种试剂在多层或模板内的组装顺序对其细胞内和细胞外功能的影响。与另一种药物传递系统，细胞穿透肽(CPP)和AT的复合体的直接比较，应该有助于确立LBL微载体的优势。此外，还将研究LBL微载体在额外的脂层表面修饰方面的摄取行为和吞噬酶体处理。这种修饰对于功能分子(抗体，CPP)或活性物质的特定结合是一个有趣的平台，尽管多层嵌入的活性物质的可用性和释放谱仍然未知。预计所获得的数据将支持开发新的和高度特异性的药物输送系统，特别是通过使用逐层技术的多功能属性。

The treatment of chronic inflammation represents an important medical challenge in the modern world. The application of systemically acting pharmaceuticals is often accompanied by multiple side effects. Therefore, the development of new drug delivery systems has to consider targeted and locally sustained applications of pharmaceuticals with high efficiency and reduced side effects.Layer by Layer (LbL) coated microcarriers represent an excellent choice for the treatment of local inflammations occurring, for instance, in arthritic joints. The modular principle of construction, that is the step-wise adsorption of oppositely charged polyelectrolytes onto a spherical micro-template forming a multilayer for an integration of active agents, offers many advantages: Using biocompatible and biodegradable polymers, time controlled and sustained release of one or more active agents, specific cell targeting and high biocompatibility can be realized. The subject of this proposal is to continue the conceptual development and investigation of those specific carriers regarding the transport of antiinflammatory substances into inflamed tissues. Here, neutrophils are in the focus of the investigations: These immune cells generate continuously considerable amounts of aggressive enzymes which contribute to chronification and massive tissue destruction. A specific enzyme, elastase, plays a major role in these processes. For an effective inhibition, LbL microcarriers will be designed to promote intracellular and extracellular elastase inhibition by a1antitrypsin (AT) by only one approach. Additionally, the modular construction of LbL microcarriers will be used to provide more than one active agent, but with different release kinetics: Neutrophils also release reactive oxygen species (ROS) as well as HOCl leading to the activity loss of AT. Therefore, an HOCl scavenger, cefoperazone, will be integrated into the multilayer to maintain AT activity. In this proposal, the influence of the assembling sequence of both agents within the multilayer or template on their intra and extracellular functionality will be investigated. The direct comparison with another drug delivery system, complexes of Cell Penetrating Peptide (CPP) and AT, should help to establish the advantages of LbL microcarriers. Additionally, the uptake behavior and phagolysosomal processing of the LbL microcarriers with regard to an additional lipid layer surface modification will be studied. This modification is an interesting platform for the specific binding of functional molecules (antibodies, CPP) or active agents although the availability and release profiles of the multilayer-embedded active agents are still unknown. It is expected that the obtained data will support the development of new and highly specific drug delivery systems, particularly by using the multifunctional attributes of Layer by Layer technology.