Intelligent Drug Delivery System Based on Mesoporous Silica Nanoparticles Coated with an Ultra-pH-Sensitive Gatekeeper and Poly(ethylene glycol)

2015 ◽  
Vol 5 (1) ◽  
pp. 55-58 ◽  
Author(s):  
Tianchan Chen ◽  
Wei Wu ◽  
Hong Xiao ◽  
Yanxiao Chen ◽  
Min Chen ◽  
...  
2018 ◽  
Vol 33 (2) ◽  
pp. 119-133 ◽  
Author(s):  
Jing Xu ◽  
Benkai Qin ◽  
Shujuan Luan ◽  
Peilan Qi ◽  
Yingying Wang ◽  
...  

Biodegradable pH-sensitive amphiphilic block polymer (mPEG-Hyde-PLGA) was synthesized via ring-opening polymerization, initiated from a hydrazone-containing macro-initiator. In this way, a pH-sensitive hydrazone bond was inserted into the backbone of block copolymer, linking hydrophilic poly(ethylene glycol) segment and hydrophobic poly(lactic-co-glycolic acid) segment. The copolymer self-assembled to form stable micelles with mean diameters below 100 nm and served as a drug delivery system for doxorubicin, with drug loading content of 5.3%. pH sensitivity of the hydrazone-containing micelles was investigated by changes in diameter and size distribution observed by dynamic light scattering measurements when the micelles were encountered to acidic medium. Small pieces and larger aggregates were found by transmission electron microscopy resulting from the disassociation of the micelles in acidic conditions. It was also noted that doxorubicin release from the pH-sensitive micelles is significantly faster at pH 4.0 and pH 5.0 compared to pH 7.4, while almost no difference was detected in the case of pH non-sensitive micelles. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assays on HepG-2 and MCF-7 cells revealed that doxorubicin-loaded pH-sensitive micelles had higher antitumor activity than pH-insensitive ones. This pH-sensitive drug delivery system based on hydrazone-containing block copolymer has been proved as a promising drug formulation for cancer therapy.


2018 ◽  
Vol 6 (39) ◽  
pp. 6269-6277 ◽  
Author(s):  
Yaya Cheng ◽  
Xiangyu Jiao ◽  
Liang Zhao ◽  
Yang Liu ◽  
Fang Wang ◽  
...  

Inspired by aquaporins in nature, herein, a biomimetic free-blocking on-demand drug delivery system is proposed, which is constructed by controlling the wettability of the inner surface of nanochannels on mesoporous silica nanoparticles (MSNs).


Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3321
Author(s):  
Etienne J. Slapak ◽  
Lily Kong ◽  
Mouad el Mandili ◽  
Rienk Nieuwland ◽  
Alexander Kros ◽  
...  

Pancreatic ductal adenocarcinoma (PDAC) has the worst survival rate of all cancers. This poor prognosis results from the lack of efficient systemic treatment regimens, demanding high-dose chemotherapy that causes severe side effects. To overcome dose-dependent toxicities, we explored the efficacy of targeted drug delivery using a protease-dependent drug-release system. To this end, we developed a PDAC-specific drug delivery system based on mesoporous silica nanoparticles (MSN) functionalized with an avidin–biotin gatekeeper system containing a protease linker that is specifically cleaved by tumor cells. Bioinformatic analysis identified ADAM9 as a PDAC-enriched protease, and PDAC cell-derived conditioned medium efficiently cleaved protease linkers containing ADAM9 substrates. Cleavage was PDAC specific as conditioned medium from leukocytes was unable to cleave the ADAM9 substrate. Protease linker-functionalized MSNs were efficiently capped with avidin, and cap removal was confirmed to occur in the presence of PDAC cell-derived ADAM9. Subsequent treatment of PDAC cells in vitro with paclitaxel-loaded MSNs indeed showed high cytotoxicity, whereas no cell death was observed in white blood cell-derived cell lines, confirming efficacy of the nanoparticle-mediated drug delivery system. Taken together, this research introduces a novel ADAM9-responsive, protease-dependent, drug delivery system for PDAC as a promising tool to reduce the cytotoxicity of systemic chemotherapy.


Molecules ◽  
2020 ◽  
Vol 25 (1) ◽  
pp. 195 ◽  
Author(s):  
Abdullah M Alswieleh ◽  
Abeer M Beagan ◽  
Bayan M Alsheheri ◽  
Khalid M Alotaibi ◽  
Mansour D Alharthi ◽  
...  

This paper introduces the synthesis of well-defined 2-(tert-butylamino)ethyl methacrylate-b-poly(ethylene glycol) methyl ether methacrylate diblock copolymer, which has been grafted onto mesoporous silica nanoparticles (PTBAEMA-b-PEGMEMA-MSNs) via atom transfer radical polymerization (ATRP). The ATRP initiators were first attached to the MSN surfaces, followed by the ATRP of 2-(tert-butylamino)ethyl methacrylate (PTBAEMA). CuBr2/bipy and ascorbic acid were employed as the catalyst and reducing agent, respectively, to grow a second polymer, poly(ethylene glycol) methyl ether methacrylate (PEGMEMA). The surface structures of these fabricated nanomaterials were then analyzed using Fourier Transform Infrared (FTIR) spectroscopy. The results of Thermogravimetric Analysis (TGA) show that ATRP could provide a high surface grafting density for polymers. Dynamic Light Scattering (DLS) was conducted to investigate the pH-responsive behavior of the diblock copolymer chains on the nanoparticle surface. In addition, multifunctional pH-sensitive PTBAEMA-b-PEGMEMA-MSNs were loaded with doxycycline (Doxy) to study their capacities and long-circulation time.


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