Search

Introduction: Metastatic breast cancer seriously harms women's health and is currently the tumour type with the highest mortality rate in women. Recently, the combinatorial therapeutic approaches that integrate anti-cancer drugs and genetic agents is an attractive and promising strategy for the treatment of metastatic breast cancer. Moreover, such a combination strategy requires better drug carriers that can effectively deliver the cargo to the breast cancer cells and achieve controlled release in the cells to achieve better therapeutic effects., Methods: The tumour-targeted and redox-responsive mesoporous silica nanoparticles (MSNs) functionalised with DNA aptamers (AS1411) as a co-delivery system was developed and investigated for the potential against metastatic breast cancer. Doxorubicin (Dox) was loaded onto the MSNs, while AS1411 and a small interfering RNA (siTIE2) were employed as gatekeepers via attachment to the MSNs with redox-sensitive disulfide bonds., Results: The controlled release of Dox and siTIE2 was associated with intracellular glutathione. AS1411 mediated the targeted delivery of Dox by increasing its cellular uptake in metastatic breast cancer, ultimately resulting in a lower IC50 in MDA-MB-231 cells (human breast cancer cell line with high metastatic potency), improved biodistribution in tumour-bearing mice, and enhanced in vivo anti-tumour effects. The in vitro cell migration/invasion assay and in vivo anti-metastatic study revealed synergism in the co-delivery system that suppresses cancer cell metastasis., Conclusion: The tumour-targeted and redox-responsive MSN prepared in this study are promising for the effective delivery and controlled release of Dox and siTIE2 for improved treatment of metastatic breast cancer., Competing Interests: The authors declare no competing interests., (© 2021 Zhuang et al.)

This work demonstrated the design and synthesis of multiple dye-doped silica cross-linked micellar nanoparticles (MD-SCMNPs) by encapsulating three organic dyes (fluorescein derivative (FCD), coumarin derivative (HCE) and Rhodamine b (RhB)) in SCMNPs cores for colour-tuneable sensing of cysteine (Cys) in aqueous media and in living cells. In the presence of Cys, HCE exhibited blue emission, and RhB exhibited purple emission, while FCD reacted with Cys and exhibited green fluorescence "turn-on" in the core of MD-SCMNPs. This green-light-emitting sensing product may cause "step by step" fluorescent resonance energy transfer (FRET) from HCE to the sensing product and then to RhB. Based on the FRET process in the core, MD-SCMNPs can quantitatively detect Cys by a colour change with a low limit of detection (LOD) of 0.3 μM in living cells. Furthermore, MD-SCMNPs exhibited ultrasmall size (∼12 nm) and excellent dispersity and biocompatibility, which could potentially be used as a visualized Cys sensor for health monitoring and disease prediction in the human body., (Copyright © 2018. Published by Elsevier Inc.)

We report the design and realization of yolk-shell structured nanospheres with periodic mesoporous organosilica (PMO) nanospheres or noble metal nanoparticles encapsulated in mesoporous silica shells via a selective etching method. These architectures have well controlled structure, size and morphology. The yolk-shell structured PMO@SiO2 nanoparticles can be precisely functionalized with different catalytic functionalities, even incompatible acidic and basic groups: the PMO core with amino (-NH2) groups and the mesoporous silica shell with sulfonic acid (-SO3H) groups. As a nanoreactor, the as-synthesized Au@SiO2 nanospheres show faster reduction of 4-nitrophenol than that of nitrobenzene. Furthermore, the prepared PMO-NH2@SiO2-SO3H nanoparticles can be used as bifunctional catalysts with highly efficient catalytic performance for catalyzing the deacetalization-Henry cascade reaction.

This work demonstrated the synthesis of (4E)-4-(4-(diphenylamino)benzylideneamino)-1,2-dihydro-1,5- dimethyl-2-phenylpyrazol-3-one (DBDDP) for Fe (III) detection in aqueous media and in the core of silica cross-linked micellar nanoparticles in living cells. The free DBDDP performed fluorescence enhancement due to Fe (III)-promoted hydrolysis in a mixed aqueous solution, while the DBDDP-doped silica cross-linked micellar nanoparticles (DBDDP-SCMNPs) performed an electron-transfer based fluorescence quenching of Fe (III) in living cells. The quenching fluorescence of DBDDP-SCMNPs and the concentration of Fe (III) exhibited a linear correlation, which was in accordance with the Stern-Volmer equation. Moreover, DBDDP-SCMNPs showed a low limit of detection (LOD) of 0.1 ppm and an excellent selectivity against other metal ions. Due to the good solubility and biocompatibility, DBDDP-SCMNPs could be applied as fluorescence quenching nanosensors in living cells., (Copyright © 2017 Elsevier Inc. All rights reserved.)

A multistimuli-responsive drug carrier is designed and successfully synthesized by self-assembly of thiol-modified periodic mesoporous organosilica (PMO) nanoparticles, coated gold nanoparticles (AuNPs), and mesostructured titanium dioxide (TiO2). Dye-loaded PMO-Au@TiO2 nanotablets are shown to respond to environmental changes (pH, temperature, and light) to achieve controlled release., (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Enzyme and voltage stimuli are more biologically compatible in the field of stimuli-responsive systems and release systems based on β-cyclodextrin (CD) and ferrocene (Fc) have attracted much attention. Herein, mesoporous silica nanoparticles (MSNs) have been functionalized with the ferrocenyl moiety (Fc) which interacts with β-cyclodextrin (β-CD) to form an inclusion complex on the opening of the pores. The size of the inclusion complex results in a barrier to the opening of the pores. Based on these characteristics, MSNs with nanovalves have been developed as a release system. The release system shows a clear response to heme protein (horseradish peroxidase or hemoglobin) and H2O2, glucose oxidase (GOD) with horseradish peroxidase (HRP) and glucose, or +1.5 V based on an oxidation stimulus mechanism. Modulating the amount of enzyme or the discretion of the voltage makes the release system a controlled one.

A "ship-in-a-bottle" approach to the entrapment and assembly of nanometer-sized polymer dots in hollow silica or carbon nanospheres with size-selective micropores is presented. This new type of core-shell nanospheres exhibits excellent photoluminescence properties and significant adsorption capabilities for transition-metal ions., (Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

This work demonstrated that water-soluble fluorescent hybrid materials can be successfully synthesized by use of silica cross-linked micellar nanoparticles (SCMNPs) as scaffolds to encapsulate fluorescent conjugated dyes for pH sensing, porphyrin sensing and tunable colour emission. Three dyes were separately encapsulated inside SCMNPs (short to dye-SCMNPs). Each of the dye-SCMNPs indicated longer lifetime in water than that of free dye dissolved in organic solvent. The 7-(hexadecyloxy) coumarin-3-ethylformate (HCE) encapsulated inside SCMNPs (HCE-SCMNPs) exhibited fluorescence quenching by pH change in aqueous media. Furthermore, it was confirmed that the radiative and nonradiative energy transfer processes both occurred between HCE-SCMNPs and tetraphenyl-porphyrin (TPP), which were used to synthesize the water-soluble TPP sensor. Significantly, HCE-SCMNPs doped with 5,12-dicotyl-quinacridone (8CQA) and TPP showed water-soluble white light emission (CIE (0.29, 0.34)) upon singlet excitation of 376 nm due to colour adjustment of 8CQA and energy transfer from HCE (donor) to TPP (acceptor).

A new class of silica cross-linked threadlike micelles has been successfully synthesized in the form of stable colloidal suspensions by using block copolymer P123 (EO(20)PO(70)EO(20)) as template, tetramethyl orthosilicate as silica source, and 3-aminopropyltriethoxysilane as stabilizing agent. The aggregation of threadlike hybrid micelles is suppressed by electrostatic repulsion from the positive -NH(3)(+) on the surfaces of threadlike hybrid micelles in strong acidic media. Compared with P123 micelles, the threadlike hybrid micelles have significantly improved stability against dilution. Furthermore, the threadlike hybrid micelles are potential drug carrier and have a higher loading capacity and a slower release rate., (Copyright © 2010 Elsevier Inc. All rights reserved.)

One advanced synthesis strategy for monodisperse silica cross-linked micellar core-shell nanoparticles (SCMCSNs) involves the use of organosilane termination agent R(n)Si(OR')(4 - n). In this study, we investigated the effects of the organosilane termination agent in the formation of SCMCSNs. Experimental data (synthesis results, (29)Si MAS NMR, molecule probe fluorescence spectra, etc.) from a synthesis system with Pluronic F127 as the template indicate that organosilane either covers or reacts with the surface Si-OH groups of nanoparticles. The reduction of reactive surface Si-OH groups helps to stabilize nanoparticles by avoiding aggregation. The terminating behavior of organosilane is determined by its molecular structure, including (1) the value of n, (2) the length of hydrocarbon chain R, and (3) the charge of R. Effective organosilane termination agents are also applicable to other synthesis mixtures such as the systems using Si(OC(2)H(4)OH)(4) as the silica source or F108 or Brij 700 as the template. Furthermore, we can obtain monodisperse nanoparticles by using the trisodium salt of triacetic acid N-(trimethoxysilylpropyl)ethylenediamine (TANED), which acts not only as a termination agent for the successful synthesis of SCMCSNs but also as a functional group to improve the performance of SCMCSNs in potential applications.