Nano Research

Article Title

Optimizing surface-engineered ultra-small gold nanoparticles for highly efficient miRNA delivery to enhance osteogenic differentiation of bone mesenchymal stromal cells


ultra-small gold nanoparticles, surface engineering, microRNA (miRNA) delivery, bone mesenchymal stromal cells, osteogenic differentiation


ABSTRACT Regulation of osteogenic differentiation of bone mesenchymal stromal cells (BMSCs) plays a critical role in bone regeneration. As small non-coding RNAs, microRNAs (miRNAs) play an important role in stem cell differentiation through regulating target-mRNA expression. Unfortunately, highly efficient and safe delivery of miRNAs to BMSCs to regulate their osteogenic differentiation remains challenging. Conventional inorganic nanocrystals have shown increased toxicity owing to their larger size precluding renal clearance. Here, we developed novel, surface-engineered, ultra-small gold nanoparticles (USAuNPs, <10 nm) for use as highly efficient miR-5106-delivery systems to enable regulation of BMSC differentiation. We exploited the effects of AuNPs coated layer-by-layer with polyethylenimine (PEI) and liposomes (Lipo) to enhance miR-5106-delivery activity and subsequent BMSC differentiation capacity. The PEI- and Lipo-coated AuNPs (Au@PEI@Lipo) showed negligible cytotoxicity, good miRNA-5106-binding affinity, highly efficient delivery of miRNAs to BMSCs, and long-term miRNA expression (21 days). Additionally, compared with commercial Lipofectamine 3000 and 25 kD PEI, the optimized Au@PEI@Lipo-miR-5106 nanocomplexes significantly enhanced BMSC differentiation into osteoblast-like cells through activation of the Sox9 transcription factor. Our findings reveal a promising strategy for the rational design of ultra-small inorganic nanoparticles as highly efficient miRNA-delivery platforms for tissue regeneration and disease therapy.

Graphical Abstract


Tsinghua University Press