Rueda Fabián, Céspedes María Virtudes, Sánchez-Chardi Alejandro, Seras-Franzoso Joaquin, Pesarrodona Mireia, Ferrer-Miralles Neus, Vázquez Esther, Rinas Ursula, Unzueta Ugutz, Mamat Uwe, Mangues Ramón, García-Fruitós Elena, Villaverde Antonio
Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona, Bellaterra, Cerdanyola del Vallès, 08193, Barcelona, Spain.
Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona, Bellaterra, Cerdanyola del Vallès, 08193, Barcelona, Spain.
Microb Cell Fact. 2016 Apr 8;15:59. doi: 10.1186/s12934-016-0457-z.
Production of recombinant drugs in process-friendly endotoxin-free bacterial factories targets to a lessened complexity of the purification process combined with minimized biological hazards during product application. The development of nanostructured recombinant materials in innovative nanomedical activities expands such a need beyond plain functional polypeptides to complex protein assemblies. While Escherichia coli has been recently modified for the production of endotoxin-free proteins, no data has been so far recorded regarding how the system performs in the fabrication of smart nanostructured materials.
We have here explored the nanoarchitecture and in vitro and in vivo functionalities of CXCR4-targeted, self-assembling protein nanoparticles intended for intracellular delivery of drugs and imaging agents in colorectal cancer. Interestingly, endotoxin-free materials exhibit a distinguishable architecture and altered size and target cell penetrability than counterparts produced in conventional E. coli strains. These variant nanoparticles show an eventual proper biodistribution and highly specific and exclusive accumulation in tumor upon administration in colorectal cancer mice models, indicating a convenient display and function of the tumor homing peptides and high particle stability under physiological conditions.
The observations made here support the emerging endotoxin-free E. coli system as a robust protein material producer but are also indicative of a particular conformational status and organization of either building blocks or oligomers. This appears to be promoted by multifactorial stress-inducing conditions upon engineering of the E. coli cell envelope, which impacts on the protein quality control of the cell factory.
在工艺友好且无内毒素的细菌工厂中生产重组药物，目标是简化纯化过程的复杂性，并在产品应用过程中将生物危害降至最低。在创新的纳米医学活动中开发纳米结构重组材料，将这种需求从简单的功能性多肽扩展到复杂的蛋白质组装体。虽然最近已对大肠杆菌进行改造以生产无内毒素的蛋白质，但迄今为止，尚无关于该系统在制造智能纳米结构材料方面表现如何的数据。
我们在此探索了用于结直肠癌中药物和成像剂细胞内递送的靶向CXCR4的自组装蛋白质纳米颗粒的纳米结构以及体外和体内功能。有趣的是，与在传统大肠杆菌菌株中产生的对应物相比，无内毒素材料呈现出可区分的结构、改变的尺寸和靶细胞穿透性。在结直肠癌小鼠模型中给药后，这些变体纳米颗粒最终显示出适当的生物分布，并在肿瘤中高度特异性和排他性地积累，表明肿瘤归巢肽的便利展示和功能以及在生理条件下的高颗粒稳定性。
此处的观察结果支持新兴的无内毒素大肠杆菌系统作为一种强大的蛋白质材料生产者，但也表明构建块或寡聚体具有特定的构象状态和组织。这似乎是由大肠杆菌细胞膜工程过程中的多因素应激诱导条件所促进的，这些条件影响细胞工厂的蛋白质质量控制。
