Mesoporous silica coated SPIONs containing curcumin and silymarin intended for breast cancer therapy

INTRODUCTION

Super-paramagnetic iron oxide nanoparticles (SPIONs) are known as promising theranostic nano-drug carriers with magnetic resonance imaging (MRI) properties. Applying the herbaceous components with cytotoxic effects as cargos can suggest a new approach in the field of cancer-therapy. In this study mesoporous silica coated SPIONs (mSiO2@SPIONs) containing curcumin (CUR) and silymarin (SIL) were prepared and evaluated on breast cancer cell line, MCF-7.

METHODS

Nanoparticles (NPs) were formulated by reverse microemulsion method and characterized by DLS, SEM and VSM. The in vitro drug release, cellular cytotoxicity, and MRI properties of NPs were determined as well. The cellular uptake of NPs by MCF-7 cells was investigated through LysoTracker Red staining using confocal microscopy.

RESULTS

The MTT results showed that the IC50 of CUR + SIL loaded mSiO2@SPIONs was reduced about 50% in comparison with that of the free drug mixture. The NPs indicated proper MRI features and cellular uptake through endocytosis.

CONCLUSION

In conclusion the prepared formulation may offer a novel theranostic system for breast cancer researches.

Ab Initio Simulation of Amorphous Graphite

An amorphous graphite material has been predicted from molecular dynamics simulation using ab initio methods. Carbon materials reveal a strong proclivity to convert into a sp^{2} network and then layer at temperatures near 3000 K within a density range of ca. 2.2-2.8  g/cm^{3}. Each layer of amorphous graphite is a monolayer of amorphous graphene including pentagons and heptagons in addition to hexagons, and the planes are separated by about 3.1  Å. The layering transition has been studied using various structural and dynamical analyses. The transition is unique as one of partial ordering (long range order of planes and galleries, but topological disorder in the planes). The planes are quite flat, even though monolayer amorphous graphene puckers near pentagonal sites. Interplane cohesion is due partly to non-Van der Waals interactions. The structural disorder has been studied closely, especially the consequences of disorder to electronic transport. It is expected that the transition elucidated here may be salient to other layered materials.

A bioinspired stimuli-responsive amino acid-based antibacterial drug delivery system in cancer therapy

Design of tyrosine based stimuli responsive antibacterial drug delivery system with potential application in cancer therapy.

Recent advances in magnetic carbon nanotubes: synthesis, challenges and highlighted applications

Magnetic carbon nanotubes (MCNTs), consisting of carbon nanotubes (CNTs) and magnetic nanoparticles (MNPs), have enormous exploration and application potentials due to their superior physical and chemical properties, such as unique magnetism and high enrichment performance. This review concentrates on the rapid advances in the synthesis and application of magnetic carbon nanotubes. Great progress has been made in the preparation of MCNTs by developing methods including chemical vapor deposition, pyrolysis procedure, sol-gel process, template-based synthesis, filling process and hydrothermal/solvothermal method. Various applications of MCNTs as a mediator of the adsorbent in magnetic solid-phase extraction, sensors, antibacterial agents, and imaging system contrast agents, and in drug delivery and catalysis are discussed. In order to overcome the drawbacks of MCNTs, such as sidewall damage, lack of convincing quantitative characterization methods, toxicity and environmental impact, and deficiency of extraction performance, researchers proposed some solutions in recent years. We systematically review the latest advances in MCNTs and discuss the direction of future development.

Control of the temperature responsiveness of poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) copolymer using ultrasonic irradiation

Poly(N-isopropylacrylamide-co-2-hydroxyethyl methacrylate) (poly(NIPAM-co-HEMA)) is a temperature-responsive copolymer that is expected to be applicable as an advanced functional polymeric material in various fields. In this study, a novel method was developed to control the responsive temperature of poly(NIPAM-co-HEMA) using an ultrasonic polymerization technique. Initially, the behavior of the reaction was investigated using NIPAM and HEMA monomers under ultrasonic irradiation. A high ultrasonic power was found to produce a high reaction rate and low number average molecular weight of the copolymer. The polydispersity of the synthesized copolymer was approximately 1.5 for all ultrasonic powers examined. In the early stage of the reaction, the molar fraction of NIPAM in the copolymer was lower than the initial molar fraction of the monomers. It was concluded that ultrasonic irradiation affected the initiation reaction and polymer degradation, but did not affect the propagation reaction. Furthermore, the effect of the ultrasonic irradiation conditions on the temperature responsiveness of the copolymer was investigated. The lower critical solution temperature (LCST) of the copolymer was found to increase with increasing ultrasonic irradiation time. In addition, in the early stages of the reaction, the measured values of the LCST were higher than the estimated values using copolymer composition. This can be attributed to some parts of the copolymer chain possessing a higher NIPAM fraction than the overall fraction due to different reactivities of the monomers and terminated radicals. This hypothesis was indirectly verified by the synthesis of a block copolymer from the PNIPAM homopolymer and HEMA monomer.

In Vitro Evaluation of DSPE-PEG (5000) Amine SWCNT Toxicity and Efficacy as a Novel Nanovector Candidate in Photothermal Therapy by Response Surface Methodology (RSM)

Nowadays, finding a novel, effective, biocompatible, and minimally invasive cancer treatment is of great importance. One of the most promising research fields is the development of biocompatible photothermal nanocarriers. PTT (photothermal therapy) with an NIR (near-infrared) wavelength range (700–2000 nm) would cause cell death by increasing intercellular and intracellular temperature. PTT could also be helpful to overcome drug resistance during cancer treatments. In this study, an amine derivative of phospholipid poly ethylene glycol (DSPE-PEG (5000) amine) was conjugated with SWCNTs (single-walled carbon nanotubes) to reduce their intrinsic toxicity. Toxicity studies were performed on lung, liver, and ovarian cancer cell lines that were reported to show some degree of drug resistance to cisplatin. Toxicity results suggested that DSPE-PEG (5000) amine SWCNTs might be biocompatible photothermal nanocarriers in PTT. Therefore, our next step was to investigate the effect of DSPE-PEG (5000) amine SWCNT concentration, cell treatment time, and laser fluence on the apoptosis/necrosis of SKOV3 cells post-NIR exposure by RSM and experimental design software. It was concluded that photothermal efficacy and total apoptosis would be dose-dependent in terms of DSPE-PEG (5000) amine SWCNT concentration and fluence. Optimal solutions which showed the highest apoptosis and lowest necrosis were then achieved.

Carbon nanotube embedded cyclodextrin polymer derived injectable nanocarrier: A multiple faceted platform for stimulation of multi-drug resistance reversal

A combination of cocktail chemotherapy (CCT), photothermal therapy (PTT) and inhibition of angiogenesis was investigated as an effective approach to combat major challenges of multidrug resistance and non-targeted drug delivery encountered in conventional cancer therapy. An injectable nanocarrier was developed through functionalization of carbon nanotubes (CNTs) with rationally modified carbohydrate (β-Cyclodextrin-CD) derived pH and thermo responsive polymer. Embedding CNT to CD polymer offers a nanocarrier which effectively demonstrated CCT, high NIR triggered photothermal efficiency, anti-angiogenic potential for selective tumor homing as well as enhanced multi-drug resistance (MDR) reversal with minimal toxic effects on normal cells. The simultaneously loading with curcumin and doxorubicin hydrochloride exhibited synergistic effect for triggering antitumor effect in vitro and demonstrated down regulation of growth factors associated with angiogenesis ex-ovo. In-vivo studies ascertained that the nanocarrier synthesized with the rational for MDR reversal can lead to enhanced cancer cell death via multiple approaches.

Amphiphilic hyperbranched polyester coated rod mesoporous silica nanoparticles for pH-responsive doxorubicin delivery

Rod-like mesoporous silica nanoparticles with pH-responsive amphiphilic hyperbranched polyester shells were prepared for doxorubicin (DOX) delivery. First, rod-shaped mesoporous silica nanoparticles (MSNs) were obtained, then hydrophobic hyperbranched polyester Boltorn H40 (H40) was grafted on their surface. The H40 coated MSNs were next treated with amine-functionalized polyethylene glycol (PEG) to achieve the hydrophilic and pH-responsive material denoted as PEG-H40-MSNs. The experimental results showed that PEG-H40-MSNs were successfully synthesized. BET analysis showed that rod MSNs exhibits a type IV standard isotherm. TEM revealed that the thin gray polymer layer was formed around the SBA-15 particle with a diameter of around 150 nm. DOX was effectively loaded, which can be released according to the ambient pH inside the cell as follow: at pH 7.4, only 9.7% of the DOX was released after 48 h; as the pH decreased to 5.5, the cumulative release reached to 49% at the same time. PEG-H40-MSNs showed less than 1.6% of hemolytic activity and a slight effect on the liver and kidney of treated mice were observed at a high disposal dosage implying negligible toxicities were caused by PEG-H40-MSNs in both in vitro hemolysis analysis and in vivo biochemical in mice. However, the in vitro cytotoxicity evaluation of the DOX-PEG-H40-MSNs showed that the cell cytotoxicity of both pure DOX and DOX-loaded PEG-H40-MSNs generally enhanced by increasing the concentration of DOX. Graphical abstract Schematic of cellular uptake and DOX release of PEG-H40-MSNs nanoparticle.

New electroactive macromonomers and multi-responsive PEDOT graft copolymers

Poly(3,4-ethylenedioxithiophene) (PEDOT) is the conducting polymer with the biggest prospects in the field of organic electronics due to its high electrical conductivity and transparency as thin films.

A dual-responsive, hyaluronic acid targeted drug delivery system based on hollow mesoporous silica nanoparticles for cancer therapy

A novel enzyme and redox dual-responsive targeted drug delivery system based on hollow mesoporous silica nanoparticles was developed for cancer therapy.

Ultrasound-assisted synthesis of pH-responsive nanovector based on PEG/chitosan coated magnetite nanoparticles for 5-FU delivery

pH-responsive magnetic carriers at the nanoscale are one of the most important agents for the targeted treatment of cancer. In this study, Fe₃O₄ nanoparticles were prepared by co-precipitation method and functionalized with three types of PEG using ultrasound waves. PEGlated particles were modified with chitosan shell through ultrasound-assisted double emulsion method. The prepared material which was used as a pH responsive carrier for pinpointed 5-FU delivery. The chemico-physical properties of prepared nanoparticles have been investigated. Results demonstrated that pure Fe₃O₄ had a mean diameter of 20nm with the regular spherical shape which was increased after modification step depending on the type of PEG. 5-FU loading properties and releasing behaviors studies in different pHs which showed that 5-FU can be efficiently loaded in the Fe₃O₄@Cs-PEG. Also, in the case of release, the amount of 5-FU released at pH=5.8 is noticeably higher compared to the released amount at pH=7.4 in all three samples at any distinct time. For instance at pH=7.4, 27% of the 5-FU was released from the Fe₃O₄@Cs-PEG2 during 48h; as the pH decreases to 5.8, the cumulative amount of 5-FU released enhanced to 52%. The in vitro MTT assay results demonstrated that the cell viability decreases in all synthesized nanoparticles as the pH medium of MCF-7 culture became to 5.8. For example, cell viability of Fe₃O₄@Cs-sPEG decreased from 44±2% to 36±1.9% at a concentration of 5 (μg/ml) as the pH varied from 7.4 to 5.8.

Dendritic chitosan as a magnetic and biocompatible nanocarrier for the simultaneous delivery of doxorubicin and methotrexate to MCF-7 cell line

A novel smart, biocompatible, and pH-responsive magnetic highly branched chitosan was synthesized efficiently for use in dual-anticancer drug delivery systems.

Recent Advances in Stimuli-Responsive Release Function Drug Delivery Systems for Tumor Treatment

Benefiting from the development of nanotechnology, drug delivery systems (DDSs) with stimuli-responsive controlled release function show great potential in clinical anti-tumor applications. By using a DDS, the harsh side effects of traditional anti-cancer drug treatments and damage to normal tissues and organs can be avoided to the greatest extent. An ideal DDS must firstly meet bio-safety standards and secondarily the efficiency-related demands of a large drug payload and controlled release function. This review highlights recent research progress on DDSs with stimuli-responsive characteristics. The first section briefly reviews the nanoscale scaffolds of DDSs, including mesoporous nanoparticles, polymers, metal-organic frameworks (MOFs), quantum dots (QDs) and carbon nanotubes (CNTs). The second section presents the main types of stimuli-responsive mechanisms and classifies these into two categories: intrinsic (pH, redox state, biomolecules) and extrinsic (temperature, light irradiation, magnetic field and ultrasound) ones. Clinical applications of DDS, future challenges and perspectives are also mentioned.