Citrate reduced colloidal silver nanoparticles (c-AgNPs) as synthesized and modified with oligonucleotides (Oligo-AgNPs) are comparatively evaluated for their wound healing properties on animal models. The healing progress was monitored daily during nine days by measuring the wound diameter. The tissue samples from the healed regions were analyzed for epithelial damage, congestion, inflammatory cell infiltration, fibroblast proliferation, and new collagen synthesis. The c-AgNPs and Oligo-AgNPs had statically significant impact on the healing process compared to control. The histological analysis revealed that the c-AgNPs and Oligo-AgNPs improved the congestion, inflammatory cell infiltration, fibroblast proliferation and new collagen synthesis as compared to control. Although the fibroblast proliferation seems to be the same for both c-AgNPs and Oligo-AgNPs, the collagen synthesis is markedly improved with the Oligo-AgNPs. The atomic spectroscopy analysis of the samples from different tissues showed that the AgNPs applied topically to the skin does not pass through the other organs. Our data suggest that topical application of Oligos-AgNPs improve wound healing by promoting increased collagen synthesis and tissue re-modeling without any side effects.

Self-assembly of 13 nm gold nanoparticles (AuNPs) engineered into 2D structures in solution using DNA tiles for their possible use for gene delivery and photothermal therapy is reported. The two different DNA tiles were constructed and the AuNPs coated with oligonucleotides possessing complementary sequence from the free ends were hybridized with the sticky ends of the tiles. The DNA tiles were bind to each other by mixing the tile structures without a heating and cooling step. The constructed nanostructures were 5 to 7 DNA tiles long since heat was not used to elongate them. When the DNA tiles were bound to the AuNPs, it was observed that AuNPs tend to stay in close proximity by filling the gaps between tiles. The stability of the constructed structures was tested against DNase, a DNA cleaving enzyme, for possible applications for gene delivery and photothermal therapy. It was found that the AuNP bound DNA tile structures resist the DNase cleavage up to eighty percent. Due to the presence of the AuNPs in the structure, the enzyme cannot bind to DNA sequences and this increases the DNA tile structures’ stability.