Biopebble Containers: DNA‐Directed Surface Assembly of Mesoporous Silica Nanoparticles for Cell Studies

Abstract

The development of methods for colloidal self‐assembly on solid surfaces is important for many applications in biomedical sciences. Toward this goal, described is a versatile class of mesoporous silica nanoparticles (MSN) that contain on their surface various types of DNA molecules to enable their self‐assembly into micropatterned surface architectures useful for cell studies. Monodisperse dye‐doped MSN are synthesized by biphase stratification and functionalized with an aptamer oligonucleotide that serves as gatekeeper for the triggered release of encapsulated molecular cargo, such as fluorescent dye rhodamine B or the anticancer drug doxorubicin. One or two additional types of oligonucleotides are installed on the MSN surface to enable DNA‐directed immobilization on solid substrates bearing patterns of complementary capture oligonucleotides. It is demonstrated that this strategy can be used for efficient self‐assembly of microstructured surface architectures, which not only promote the adhesion and guidance of cells but also are capable of affecting the fate of adhered cells through triggered release of their cargo. It is believed that this approach is useful for diverse applications in tissue engineering and nanobio sciences.

Segregation of Dispersed Silica Nanoparticles in Microfluidic Water‐in‐Oil Droplets: A Kinetic Study

“…We also established, as a proof‐of‐concept, that other types of DNA‐modified silica nanoparticles can be analyzed by our method. Specifically, we confirmed that mesoporous silica nanoparticles (MSN) modified with single‐stranded DNA oligomers on their surface, here denoted as MSN‐DNA (Table ), can as well be employed in the self‐assembly process at the inner surface of DOTAP droplets (Figure S10). Since MSN can be used as nanocontainers for targeted delivery of small molecules, these results open up further perspectives for the development of highly functional supramolecular architectures within microfluidic droplets, which could be used, for example, for the cultivation and analysis of cells.…”

“…For the activation of thiolated oligonucleotides (100 μL,100 μM), they were incubated with DTT (60 μL, 1 M, 37 °C) for two hours. The oligonucleotides were then purified with NAP‐5 and NAP‐10 column according to a previously described procedure …”

“…For the synthesis of MSN‐DNA , MSN grafted with thiol groups were synthesized and modified with thiolated oligonucleotides (22 mer, Table S1) using the previously reported protocol . The resulting MSN‐DNA were stored in water until further use.…”

“…The quantification of amine ( SiNP‐2 ) and thiol ( SiNP‐4 ) groups was achieved by the fluorescamine assay and Ellman's assay, respectively, using the previously described protocol . The conjugated oligonucleotides and BSA were quantified using the supernatant depletion method by measuring the absorbance of the supernatant at 260 nm (for DNA) and 280 nm (for BSA) before and after the conjugation reaction …”

Random access DNA memory in a scalable, archival file storage system

“…DNA hybridization assay was used to estimate the number of surface-accessible DNA barcodes [9][10][11] . In a typical experiment, we add 1 µL of 500 µM of TYE705-modified single-stranded DNA probe to a 1.5 mL Eppendorf LoBind tube that contains 50 µL of 2 mg mL -1 of files that has surface-attached barcodes that are complementary to the TYE705-modified DNA probe sequence.…”