Optimizing mesoporous silica synthesis procedures to enhance their potential as nanoplatforms in therapeutic applications†

PARK7 mRNA encodes the DJ-1 protein, which functions as a protective agent against oxidative stress and cell damage within brain cells. Mutations in the mRNA can lead to reduced production of DJ-1 and initiate brain diseases such as Parkinson's disease. Transport of appropriate mRNA to damaged brain cells may provide a suitable treatment. Mesoporous silica nanoparticles (MSNPs), particularly pore-expanded and dye-labeled varieties, are regarded as potential carriers for large therapeutic agents such as mRNA. This study explored the influence of alterations in reaction conditions on the structural characteristics of MSNPs to produce nanoparticles with favorable characteristics for delivering large therapeutic agents to target sites. One-stage and two-stage procedures were compared for the introduction of 3-aminopropyltriethoxysilane (APTES) and an APTES−dye adduct, in conjunction with two different surfactants, cetyltrimethylammonium bromide (CTAB) and cetyltrimethylammonium chloride (CTAC). Analysis of the MSNPs shows that the two-stage method using CTAB as a surfactant produced amine-functionalized, dye-labelled particles with smaller overall size and better uniformity than the one-stage approach. However, due to their small pore size (<10 nm), these particles were unable to encapsulate the PARK7 mRNA (926 nucleotides). The one-stage method via CTAC produced MSNPs with a large pore size (150 nm), broad pore distribution (10–20 nm), and high aggregation, limiting their suitability for brain-targeted gene delivery. In comparison, the two-stage method using CTAC yielded well-ordered MSNPs with an optimal size (80 nm) and pore diameters (15–20 nm), enabling effective encapsulation of the large PARK7 mRNA and offering strong potential for future brain gene therapy studies.