pH- SENSITIVE BIS-DETERGENTS FOR MACROMOLECULAR DELIVERY

用于大分子输送的 pH 敏感双去污剂

• 批准号: 6776804
• 负责人: MOO J CHO
• 金额: $ 20.24万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2006-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6776804
• 关键词: acidity /alkalinity; calorimetry; chemical stability; chemical structure function; chemical synthesis; confocal scanning microscopy; crosslink; cytoplasm; cytotoxicity; detergents; drug delivery systems; electron microscopy; endocytosis; fluorescence spectrometry; hydrolysis; lipid bilayer membrane; lipid metabolism; liposomes; macromolecule; membrane permeability; micelles; protonation; technology /technique development; tissue /cell culture

DESCRIPTION (provided by applicant): Macromolecules, being unable to penetrate cell membranes readily, enter the cell via endocytosis. The contents of the endosome are eventually routed to enzyme-rich lysosomes and in all likelihood degraded. If pharmacological activity of a therapeutic macromolecule is realized only when it enters the cytosol, then a mechanism must be built within a delivery system by which these agents escape from the endosome into the cytosol. The endosomal pH drops to as low as 5.0 as the endosome matures. This provides a unique opportunity in devising such a strategy for cytosolic delivery. We have designed a series of acid-sensitive lipids that can be readily incorporated into liposomal drug carrier systems. Upon entering the cell and encountering the acidic environment of the endosome, the acid sensitive lipid breaks down to release potent detergents. Critical hypotheses being tested at this point are:(1) presence of these detergents initiates liposome-to-micelle transition that triggers catastrophic release of entrapped macromolecules within endosomes and (2) micelles then induce permeabilization of endosomal membrane to promote cytosolic transfer of macromolecules. However, it is impossible to test these hypotheses without incorporating a critical concentration of detergent into liposomal bilayers. This concentration, above which vesicle-to-micelle transition can take place is unattainably high simply because at high detergent concentrations, liposomes cannot be made. In the present study, we propose to synthesize "bis-detergents", inert double-tailed lipids that can be embedded at high concentrations in liposomal bilayers and break down only at low pH into "membrane-active" detergents. When realized, the technology developed from this study will have profound implication not only in basic biomedical research entailing cytosolic delivery of macromolecules in vitro but also in a variety of therapeutic applications in vivo, ranging from delivery of antigenic proteins for induction of cell-mediated immunity to nucleic acids for gene regulation.

描述（由申请人提供）：大分子无法轻易穿透细胞膜，通过内吞作用进入细胞。最终，内体的含量被路由到富含酶的溶酶体，并且很可能会降解。如果只有在进入细胞质时才能实现治疗性大分子的药理活性，则必须在递送系统中建立机制，这些机构通过该机构从内体中逸出到细胞质中。内体pH下降到高达5.0，而内体成熟。这为制定这种胞质交付的策略提供了独特的机会。 我们设计了一系列对酸敏感的脂质，可以很容易地将其掺入脂质体药物载体系统中。进入细胞并遇到内体的酸性环境后，酸敏感的脂质分解以释放有效的洗涤剂。此时测试的关键假设是：（1）这些洗涤剂的存在引发脂质体至微粒过渡，从而触发内体内陷入的大分子的灾难性释放，然后（2）胶束，然后诱导内体膜的渗透性，以促进内体膜促进细胞质体转移。但是，如果不将临界浓度的洗涤剂浓度掺入脂质体双层体中，就不可能检验这些假设。这种浓度高于囊泡到薄膜的过渡，仅仅是因为在高清洁剂浓度下，无法制成脂质体。在本研究中，我们提议合成“双二键”，惰性双尾脂质，这些脂质可以在脂质体双层中高浓度嵌入，并仅在低pH下将其分解为“膜活性”洗涤剂。 实现后，这项研究开发的技术不仅在体外的基本生物医学研究中具有深远的影响，还需要在体外​​赋予大分子的胞质递送，而且在体内的各种治疗应用中，从抗原蛋白的递送范围从诱导细胞介导的免疫来诱导基因构成核酸来调节基因。