Pohlit Hannah, Bellinghausen Iris, Schömer Martina, Heydenreich Bärbel, Saloga Joachim, Frey Holger
Department of Dermatology, University Medical Center Mainz , Langenbeckstr. 1, 55131 Mainz, Germany.
Institute of Organic Chemistry, University of Mainz , Duesbergweg 10-14, 55128 Mainz, Germany.
Biomacromolecules. 2015 Oct 12;16(10):3103-11. doi: 10.1021/acs.biomac.5b00458. Epub 2015 Sep 11.
In the last decades, the number of allergic patients has increased dramatically. Allergen-specific immunotherapy (SIT) is the only available cause-oriented therapy so far. SIT reduces the allergic symptoms, but also exhibits some disadvantages; that is, it is a long-lasting procedure and severe side effects like anaphylactic shock can occur. In this work, we introduce a method to encapsulate allergens into nanoparticles to avoid severe side effects during SIT. Degradable nanocarriers combine the advantage of providing a physical barrier between the encapsulated cargo and the biological environment as well as responding to certain local stimuli (like pH) to release their cargo. This work introduces a facile strategy for the synthesis of acid-labile poly(ethylene glycol) (PEG)-macromonomers that degrade at pH 5 (physiological pH inside the endolysosome) and can be used for nanocarrier synthesis. The difunctional, water-soluble PEG dimethacrylate (PEG-acetal-DMA) macromonomers with cleavable acetal units were analyzed with 1H NMR, SEC, and MALDI-ToF-MS. Both the allergen and the macromonomers were entrapped inside liposomes as templates, which were produced by dual centrifugation (DAC). Radical polymerization of the methacrylate units inside the liposomes generated allergen-loaded PEG nanocarriers. In vitro studies demonstrated that dendritic cells (DCs) internalize the protein-loaded, nontoxic PEG-nanocarriers. Furthermore, we demonstrate by cellular antigen stimulation tests that the nanocarriers effectively shield the allergen cargo from detection by immunoglobulins on the surface of basophilic leucocytes. Uptake of nanocarriers into DCs does not lead to cell maturation; however, the internalized allergen was capable to induce T cell immune responses.
在过去几十年中,过敏患者的数量急剧增加。变应原特异性免疫疗法(SIT)是目前唯一可用的针对病因的疗法。SIT可减轻过敏症状,但也存在一些缺点;也就是说,这是一个长期的过程,可能会出现如过敏性休克等严重副作用。在这项工作中,我们介绍了一种将变应原封装到纳米颗粒中的方法,以避免SIT期间出现严重副作用。可降解纳米载体兼具在封装的货物与生物环境之间提供物理屏障以及响应某些局部刺激(如pH值)以释放其货物的优点。这项工作介绍了一种简便的策略,用于合成在pH 5(溶酶体内的生理pH值)下会降解且可用于纳米载体合成的酸不稳定聚乙二醇(PEG)大分子单体。用1H NMR、SEC和MALDI-ToF-MS分析了带有可裂解缩醛单元的双功能水溶性PEG二甲基丙烯酸酯(PEG-缩醛-DMA)大分子单体。变应原和大分子单体都作为模板包裹在脂质体内,脂质体通过双重离心(DAC)制备。脂质体内甲基丙烯酸酯单元的自由基聚合产生了负载变应原的PEG纳米载体。体外研究表明,树突状细胞(DCs)会内化负载蛋白质的无毒PEG纳米载体。此外,我们通过细胞抗原刺激试验证明,纳米载体有效地保护变应原货物不被嗜碱性白细胞表面的免疫球蛋白检测到。纳米载体被DCs摄取不会导致细胞成熟;然而,内化的变应原能够诱导T细胞免疫反应。