TY - JOUR
T1 - PH-controlled release of substrates from mesoporous SiO2 nanoparticles gated by metal ion-dependent DNAzymes
AU - Zhang, Zhanxia
AU - Wang, Fuan
AU - Balogh, Dora
AU - Willner, Itamar
PY - 2014/7/28
Y1 - 2014/7/28
N2 - The pH-controlled release of substrates from mesoporous SiO2 nanoparticles, MP-SiO2 NPs, is demonstrated by capping the pores with the Mg2+- or UO22+-dependent DNAzyme sequences and unlocking of the pores with Mg2+ ions or UO2 2+ ions at appropriate pH values. While the Mg2+-dependent DNAzyme reveals high activity at pH = 7.2, moderate activity at pH = 6.0, and it lacks activity at pH = 5.2, the UO22+-dependent DNAzyme reveals high activity at pH = 5.2, moderate activity at pH = 6.0, and it is catalytically inactive at pH = 7.2. Accordingly, the MP-SiO2 NPs were loaded with methylene blue, MB+, or thionine, Th+, and locked in the pores by the Mg2+- and UO2 2+-dependent DNAzyme sequences, respectively. The pH-programmed release of MB+ or Th+ from the loaded NPs proceeds, in the presence of Mg2+ ions or UO22+ ions, at pH = 7.2 and pH = 5.2, using the Mg2+- and UO2 2+-dependent DNAzyme as catalysts that cleave the protecting caps and unlock the pores, respectively. At pH = 6.0 the MB+- and Th +-loaded NPs are concomitantly unlocked by the two DNAzymes. The unlocking processes are selective and other metal ions do not stimulate the release processes. This journal is
AB - The pH-controlled release of substrates from mesoporous SiO2 nanoparticles, MP-SiO2 NPs, is demonstrated by capping the pores with the Mg2+- or UO22+-dependent DNAzyme sequences and unlocking of the pores with Mg2+ ions or UO2 2+ ions at appropriate pH values. While the Mg2+-dependent DNAzyme reveals high activity at pH = 7.2, moderate activity at pH = 6.0, and it lacks activity at pH = 5.2, the UO22+-dependent DNAzyme reveals high activity at pH = 5.2, moderate activity at pH = 6.0, and it is catalytically inactive at pH = 7.2. Accordingly, the MP-SiO2 NPs were loaded with methylene blue, MB+, or thionine, Th+, and locked in the pores by the Mg2+- and UO2 2+-dependent DNAzyme sequences, respectively. The pH-programmed release of MB+ or Th+ from the loaded NPs proceeds, in the presence of Mg2+ ions or UO22+ ions, at pH = 7.2 and pH = 5.2, using the Mg2+- and UO2 2+-dependent DNAzyme as catalysts that cleave the protecting caps and unlock the pores, respectively. At pH = 6.0 the MB+- and Th +-loaded NPs are concomitantly unlocked by the two DNAzymes. The unlocking processes are selective and other metal ions do not stimulate the release processes. This journal is
UR - http://www.scopus.com/inward/record.url?scp=84903440334&partnerID=8YFLogxK
U2 - 10.1039/c4tb00558a
DO - 10.1039/c4tb00558a
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AN - SCOPUS:84903440334
SN - 2050-7518
VL - 2
SP - 4449
EP - 4455
JO - Journal of Materials Chemistry B
JF - Journal of Materials Chemistry B
IS - 28
ER -