One-pot synthesis of compact DNA silica particles for gene delivery and extraordinary DNA preservation

Abstract

Repairing genetic defects using exogenous DNA is a major challenge the science is currently facing. This requires the design of vectors that can effectively encapsulate, protect and target nucleic acids to specific cells safely and precisely. Here we have designed silica-based physiologically responsive particles to encapsulate, store, and transfer DNA. Unlike existing vectors (e.g., viral or lipidic particles), these DNA@SiO2 systems are very stable at room temperature. We also demonstrate how they protect the encapsulated DNA from exposure to different biological and physicochemical stresses, including DNase, denaturation temperatures (>100 °C), or reactive oxygen species (ROS). Remarkably, upon cellular uptake, these vectors dissolve safely unpacking the DNA and transfecting the cells.The versatility of the design is such that it can encapsulate genes without gene/size restrictions, in single or multiple layers of silica, so different genes can be expressed sequentially. This allows the time-controlled transcription of several genes, mimicking viral gene expression cascades, or even “fine-tuning” gene expression in transfected cells on demand. In addition, the method is easily scalable, reproducible, and inexpensive, enabling large-scale production and batch-quality testing, all of which are important for the personalized therapeutics industry. The high stability of these DNA vectors allows for easy and low-cost transport from the point of production to virtually any destination, making them unique as gene delivery tools.

Keywords

• Transfection
• Silica
• Gene transfer
• Nanoparticle
• Sequential-gene expression