Silica Microcapsules for Long‐Term, Robust, and Reliable Room Temperature RNA Preservation

Abstract

As a consequence of the latest revolutionary discoveries on its functions, RNA is certainly the hottest topic at the moment, being an exceptional tool in biology as well as in medicine. For the various applications, a proper RNA storage is required to prevent the degradation of this extremely unstable molecule. Here a novel freezing-free RNA storage strategy is presented, based on its encapsulation in silica spheres. The silica microcapsules protect the RNA by providing a water-free environment. In this way RNA can be safely stored for prolonged periods of time at ambient and elevated temperatures, maintaining its original integrity, as proved by gel-electrophoresis, capillary electrophoresis, and real-time reverse transcription-polymerase chain reaction (RT-qPCR). The RNA degradation rate at 65 °C in silica microcapsules is approximately ten times smaller in comparison to dry RNA samples or to samples stored in RNAstable matrix, a commercially available product. Moreover, RNA half-life at 65 °C is nearly identical to that of DNA within the silica microcapsules. Samples intended for use in gene expression are compatible with further analysis (RT-qPCR, Sanger sequencing). The novel storage technology permits to safely handle, store, and transport RNA samples, avoiding the expensive shipments and the problems of space presented by freezing-based strategies.

Submicrometer-Sized Thermometer Particles Exploiting Selective Nucleic Acid Stability

“…As previously reported in literature, a fi rst-order nucleic acid decay kinetics was observed. [ 13,14 ] Additionally, as predicted, RNA decayed faster than DNA at all the examined temperatures ( Figure S7, Supporting Information). In Figure S8 (Supporting Information), the Δ C t is reported versus time for the various temperatures, exhibiting the expected linearity.…”

“…[ 13 ] Based on this assumption, the natural choice would be to use DNA as reference, and RNA as sensing element.…”

“…In previous studies, we have developed a technique to improve nucleic acid (both DNA and ribonucleic acid (RNA) stability against enzymatic (RNases), thermal and chemical stress by encapsulating them within silica and magnetic silica particles (with an iron oxide core). We have shown that the nucleic acids can be quantified by quantitative real‐time polymerase chain reaction (qPCR) after particle dissolution using a fluoride buffer.…”

Silica Mineralization of DNA‐Inspired 1D and 2D Supramolecular Polymers

“…Introducing co‐interacting reagents was a major breakthrough, which led to the various applications, including chiral optical materials . Recently, Grass and co‐workers showed that silica is a perfect environment to preserve nucleic acids for the information storage and biomedical purposes . Mirkin and co‐workers used silicification to generate stable nanoparticle superlattices, which were further converted into catalytically active materials …”

Immobilizing and de-immobilizing enzymes on mesoporous silica

“…Both strategies however, have not solved the large substrate limitations. Following on previous unsuccessful attempts to directly encapsulate proteins in silica in analogy to encapsulating DNA/RNA (see supporting info), [18][19][20][21] we took advantage of literature knowledge on enzyme immobilization on mesoporous materials. To further overcome the disadvantages that immobilized enzymes have during application, we herein report a novel approach to stably entrap enzymes and release them on demand (Scheme 1).…”