Porous silicon-based nanostructured microparticles as degradable supports for solid-phase synthesis and release of oligonucleotides

We describe the preparation of several types of porous silicon (pSi) microparticles as supports for the solid-phase synthesis of oligonucleotides. The first of these supports facilitates oligonucleotide release from the nanostructured support during the oligonucleotide deprotection step, while the second type of support is able to withstand the cleavage and deprotection of the oligonucleotides post synthesis and subsequently dissolve at physiological conditions (pH = 7.4, 37°C), slowly releasing the oligonucleotides. Our approach involves the fabrication of pSi microparticles and their functionalisation via hydrosilylation reactions to generate a dimethoxytrityl-protected alcohol on the pSi surface as an initiation point for the synthesis of short oligonucleotides.