A robust method for fabrication of monodisperse magnetic mesoporous silica nanoparticles with core-shell structure as anticancer drug carriers

Synthesis of quercetin-loaded hyaluronic acid-conjugated pH/redox dual-stimuli responsive poly(methacrylic acid)/mesoporous organosilica nanoparticles for breast cancer targeted therapy

In the current study, a combination of precipitation polymerization and modified sol-gel methods were developed to prepare the novel hyaluronic acid-decorated pH and redox dual-stimuli responsive poly(methacrylic acid)/mesoporous organosilica nanoparticles with a core-shell structure for controlled drug release. The nanocarriers have a proper particle size of <200 nm, high negative zeta potential greater than -30 mV, controllable diameter, and tunable shell thickness. The prepared nanoparticles were able to entrap over 70 % of quercetin with a drug loading of >10 %, due to the mesoporous shell. In vitro drug release profiles indicated that the systems had good stability under normal physiological media, while the cumulative release was significantly accelerated at the simulated tumor tissue condition, which shows pH and redox-dependent drug release. In vitro cell viability and apoptosis assay proved that the obtained nanomaterials possess relatively good biocompatibility, and drug-loaded targeted nanoparticles exhibited greater cytotoxicity on MCF-7 human breast cancer cells than free drug and non-targeted nanocarriers due to the enhanced cellular uptake of nanoparticles via CD44 receptors overexpressed. All these findings demonstrated that proposed nanocarriers might be promising as a smart drug delivery system to improve the antitumor efficacy of chemotherapeutic drugs.

Design and fabrication of intracellular therapeutic cargo delivery systems based on nanomaterials: current status and future perspectives

Intracellular cargo delivery, the introduction of small molecules, proteins, and nucleic acids into a specific targeted site in a biological system, is an important strategy for deciphering cell function, directing cell fate, and reprogramming cell behavior. With the advancement of nanotechnology, many researchers use nanoparticles (NPs) to break through biological barriers to achieving efficient targeted delivery in biological systems, bringing a new way to realize efficient targeted drug delivery in biological systems. With a similar size to many biomolecules, NPs possess excellent physical and chemical properties and a certain targeting ability after functional modification on the surface of NPs. Currently, intracellular cargo delivery based on NPs has emerged as an important strategy for genome editing regimens and cell therapy. Although researchers can successfully deliver NPs into biological systems, many of them are delivered very inefficiently and are not specifically targeted. Hence, the development of efficient, target-capable, and safe nanoscale drug delivery systems to deliver therapeutic substances to cells or organs is a major challenge today. In this review, on the basis of describing the research overview and classification of NPs, we focused on the current research status of intracellular cargo delivery based on NPs in biological systems, and discuss the current problems and challenges in the delivery process of NPs in biological systems.

Fe3O4@SiO2@KIT-6@2-ATP@CuI as a catalyst for hydration of benzonitriles and reduction of nitroarenes

In this paper, a new type of magnetic mesoporous material (Fe₃O₄@SiO₂@KIT-6@2-ATP@Cu^I) was designed and synthesized and its application in the synthesis of amides and anilines was investigated. The structure of Fe₃O₄@SiO₂@KIT-6@2-ATP@Cu^I was characterized and identified using FTIR, SEM, XRD, TGA, BET, VSM, and ICP techniques. An external magnet can easily remove the synthesized catalyst from the reaction medium, and be reused in several consequence runs.

Luminescent Composite Carbon/SiO2 Structures: Synthesis and Applications

Luminescent carbon nanostructures (CNSs) have attracted great interest from the scientific community due to their photoluminescent properties, structural features, low toxicity, and a great variety of possible applications. Unfortunately, a few problems hinder their further development. These include the difficulties of separating a mixture of nanostructures after synthesis and the dependence of their properties on the environment and the aggregate state. The application of a silica matrix to obtain luminescent composite particles minimizes these problems and improves optical properties, reduces photoluminescence quenching, and leads to wider applications. We describe two methods for the formation of silica composites containing CNSs: inclusion of CNSs into silica particles and their grafting onto the silica surface. Moreover, we present approaches to the synthesis of multifunctional particles. They combine the unique properties of silica and fluorescent CNSs, as well as magnetic, photosensitizing, and luminescent properties via the combination of functional nanoparticles such as iron oxide nanoparticles, titanium dioxide nanoparticles, quantum dots (QDs), and gold nanoclusters (AuNCs). Lastly, we discuss the advantages and challenges of these structures and their applications. The novelty of this review involves the detailed description of the approaches for the silica application as a matrix for the CNSs. This will support researchers in solving fundamental and applied problems of this type of carbon-based nanoobjects.

Sugar based cationic magnetic core-shell silica nanoparticles for nucleic acid extraction

Nucleic acid (NA) extraction is an essential step in molecular testing for a wide range of applications. Conventional extraction protocols usually suffer from time consuming removal of non-nucleic acid impurities. In this study, a new magnetic nanoparticle (MNP) is presented to simplify the NA extraction. A core–shell design, comprising of a ferromagnetic core coated with mesoporous silica, forms the basis of the functional nanoparticle. Chemical functionalization of the silica coating includes a multistep synthesis, in which an activated nanoparticle is coupled with a triethylene glycol spaced glycosyl imidazole. The molecular design aims for charge interactions between the imidazolium-based positive nanoparticle surface and nucleic acids, with specific hydrogen bonding between the surface bonded carbohydrate and nucleic acid targets to ensure nucleic acid selectivity and avoid protein contamination. Two different carbohydrates, differing in molecular size, were selected to compare the efficiency in terms of NA extraction. A triethylene glycol spacer provides sufficient flexibility to remove particle surface constraints for the interaction. The Brunauer–Emmett–Teller (BET) analysis shows a significantly larger surface area for the disaccharide-based particles NpFeSiImMalt (∼181 m² g⁻¹) compared to the monosaccharide analogue NpFeSiImGlc (∼116 m² g⁻¹) at small particles sizes (range ∼ 15 nm) and sufficient magnetization (29 emu g⁻¹) for easy isolation by an external magnetic field. The particles enabled a high DNA particle loading ratio of 30–45 wt% (MNP/DNA ratio), reflecting an efficient extraction process. A high desorption rate (7 min) with more than 86% of unchanged DNA loading was recorded, indicating low damage to the target extract.

New design of cationic magnetic core–shell nanoparticles fabricated with a large hydrophilic group (carbohydrate molecules) enabled high adsorption of a nucleic acid, easy isolation and controlled the movement by applying an external magnetic field.

Insight into the Technical Qualification of the Sonocogreen CaO/Clinoptilolite Nanocomposite (CaO(NP)/Clino) as an Advanced Delivery System for 5-Fluorouracil: Equilibrium and Cytotoxicity

Clinoptilolite as a natural zeolite was integrated with green CaO nanoparticles forming the green nanocomposite CaO_(NP)/Clino. The CaO_(NP)/Clino composite was assessed as a potential carrier for 5-fluorouracil (5-FL) drug. The CaO_(NP)/Clino carrier achieved an enhanced 5-FL loading capacity of 305.3 mg/g as compared to 163 mg/g for pure clinoptilolite. The kinetics of the 5-FL loading follow the properties of the pseudo-first-order model, while the equilibrium results are related to the Langmuir isotherm. Therefore, the 5-FL loading processes occurred in the monolayer formed by homogeneous active loading receptors on the surface of the CaO_(NP)/Clino carrier. The Gaussian energy of the 5-FL loading reaction (9.2 KJ/mol) reflected the dominant effect for the chemical mechanisms, especially the zeolitic ion-exchange mechanisms. Additionally, the thermodynamic parameters suggested endothermic, feasible, and spontaneous properties for the occurred 5-FL loading reactions. The release profile of 5-FL from CaO_(NP)/Clino has continuous and long properties (150 h) at pH 1.2 (gastric fluid) and pH 7.4 (intestinal fluid). The kinetic studies of the release reactions show considerable agreement with Higuchi, Hixson-Crowell, and Korsmeyer-Peppas models. Such high fitting results and the diffusion exponent values (0.49 at pH 1.2 and 0.48 at pH 7.4) reflected the release properties of the Fickian transport behavior involving complex erosion and diffusion mechanisms. The cytotoxicity study of CaO_(NP)/Clino on colorectal normal cells (CCD-18Co) declare the safe and biocompatible effect as a carrier for the 5-FL drug. Additionally, CaO_(NP)/Clino as a carrier causes considerable enhancement for the cytotoxic effect of the loaded 5-FL drug on colon cancer cells (HCT-116).

Preparation of hyaluronic acid-decorated mixed nanomicelles for targeted delivery of hydrophobic drugs to CD44-overexpressing cancer cells

Most of the employed methods for preparation of targeted nanoparticles containing hydrophobic herbal drugs have multiple surface modifications with time-consuming steps. The present research was aimed to develop a facile method for preparation of hyaluronic acid (HA)-decorated mixed nanomicelles loaded with curcumin (as a hydrophobic drug model) to provide an efficient drug delivery system for targeted therapy of breast cancer cells with high expression of CD44 receptor. To this end, curcumin was first encapsulated in the hydrophobic core of Pluronic F127/didecyldimethylammonium bromide (PD) mixed nanomicelles using thin-film hydration method. Then, negatively charged HA was coated on the positively charged surface of PD mixed nanomicelles via electrostatic interactions. The drug loading and entrapment efficiency of the targeted nanomicelles were 2.8% and 95.1%, respectively. The average hydrodynamic size of the prepared nanomicelles before and after coating with HA were 19.8 and 35.8 nm, respectively. Moreover, in vitro cytotoxicity analyses showed that, HA-coated PD (HA-PD) mixed nanomicelles can enhance the cytotoxicity of curcumin against MDA-MB-231 cancer cells compared to non-targeted ones (PD mixed nanomicelles), and free curcumin. The IC₅₀ concentrations of free curcumin, curcumin-loaded PD mixed nanomicelles, and curcumin-loaded HA-PD mixed nanomicelles were 4.11, 3.20, and 2.83 μg/mL, respectively, after 48 h incubation with MDA-MB-231 cancer cells. Our results suggest that, curcumin-loaded HA-PD mixed nanomicelles may be considered as a promising targeted anticancer drug delivery system for breast cancer therapy and/or delivering other hydrophobic drugs to different kinds of cancer cells with CD44-receptor overexpression.

Synthesis of FeO@SiO2-DNA core-shell engineered nanostructures for rapid adsorption of heavy metals in aqueous solutions

Creating novel and innovative nanostructures is a challenge, aiming to discover nanomaterials with promising properties for environmental remediation. In this study, the physicochemical and adsorption properties of a heterogeneous nanostructure are evaluated for the rapid removal of heavy metal ions from aqueous solutions. Core–shell nanostructures are prepared using iron oxide cores and silica dioxide shells. The core is synthesized via the co-precipitation method and modified in situ with citric acid to grow a carboxyl layer. The shell was hydrolyzed/condensed and then functionalized with amine groups for ds-DNA condensation via electrostatic interaction. The characterization techniques revealed functional FeO@SiO₂–DNA nanostructures with good crystallinity and superparamagnetic response (31.5 emu g⁻¹). The predominant superparamagnetic nature is attributed to the citric acid coating. This improves the dispersion and stability of the magnetic cores through the reduction of the dipolar–dipolar interaction and the enhancement of the spin coordination. The rapid adsorption mechanism of FeO@SiO₂–DNA was evaluated through the removal of Pb(ii), As(iii), and Hg(ii). A rapid adsorption rate is observed in the first 15 min, attributed to a heterogeneous chemisorption mechanism based on electrostatic interactions. FeO@SiO₂–DNA shows higher adsorption efficiency of 69% for Pb(ii) removal compared to As(iii) (51%) and Hg(ii) (41%). The selectivity towards Pb(ii) is attributed to the similar acid nature to ds-DNA, where the ionic strength interaction provides good affinity and stability. The facile synthesis and rapid adsorption suggest a promising nanostructure for the remediation of water sources contaminated with heavy metal ions and can be extended to other complex molecules.

Facile synthesis of well-dispersed and magnetic FeO@SiO₂–DNA nanostructures with electrostatic active sites for interaction and rapid adsorption of heavy metals.

Insight into the Loading and Release Properties of MCM-48/Biopolymer Composites as Carriers for 5-Fluorouracil: Equilibrium Modeling and Pharmacokinetic Studies

The effect of the integration between MCM-48 and some biopolymers (starch, chitosan, and β-cyclodextrin) on enhancing the pharmaceutical properties of MCM-48 as advanced carriers for the 5-fluorouracil drug was studied considering the loading capacities and the release profiles. The prepared carriers are MCM-48/chitosan (MCM/CH), MCM-48/starch composite (MCM/ST), and MCM-48/β-Cyclodextrin (MCM/CD). They emphasized excellent 5-Fu loading capacities of 141.2 mg/g (MCM-48), 156.6 mg/g (MCM/ST), 191 mg/g (MCM/CH), and 170 mg/g (MCM/CD), reflecting significant enhancement in the loading capacities. The kinetic and equilibrium investigation suggested physisorption loading of 5-Fu drug in a monolayer form for MCM-48, MCM/ST, and MCM/CH (Langmuir) and in a multilayer form for MCM/CD (Freundlich). This was supported by the estimated adsorption energies (0.23 kJ/mol (MCM-48), 0.26 kJ/mol (MCM/ST), 0.3 kJ/mol (MCM/CH), and 0.75 kJ/mol (MCM/CD)) and the thermodynamic parameters of free energy and enthalpy. The obtained release profiles for 80 h reflected significant controlling for the releasing behavior of MCM/48 on integrating its structure by adjusting the type of the selected polymer and its ratio. The pharmacokinetic modeling and the diffusion exponent from the Korsmeyer-Peppas model suggested non-Fickian transport behavior (a combination of erosion and diffusion releasing mechanism) for MCM/ST, MCM/CH, and MCM/CD and Fickian diffusion behavior (diffusion releasing mechanism) for MCM-48.

One-pot preparation of hyaluronic acid-coated iron oxide nanoparticles for magnetic hyperthermia therapy and targeting CD44-overexpressing cancer cells

In the present study, a facile one-pot hydrothermal method is introduced for preparation of hyaluronic acid-coated Fe₃O₄ nanoparticles (Fe₃O₄@HA NPs) for theranostic applications. In the proposed method, hyaluronic acid acts simultaneously as a biocompatible coating layer and as a targeting ligand for CD44 receptor overexpressed on the surface of breast cancer cells. The obtained product with narrow hydrodynamic size distribution exhibited a high colloidal stability at physiological pH for more than three months. Cytotoxicity measurements indicated a negligible toxicity of the prepared sample against L929 normal cells. Preferential targeting of Fe₃O₄@HA NPs to CD44-overexpressing cancer cells was studied by comparing the uptake of the prepared nanoparticles by MDA-MB-231 cancer cells (positive CD44 expression) and L929 normal cells (negative CD44 expression). Uptake of the Fe₃O₄@HA NPs by MDA-MB-231 cells was found to be 4-fold higher than the normal cells. Also, the in vitro analysis showed that, the uptake of Fe₃O₄@HA NPs by MDA-MB-231 breast cancer cells is significantly enhanced as compared to non-targeted dextran-coated Fe₃O₄ NPs. Moreover, the heat generation capability of the Fe₃O₄@HA NPs for magnetic hyperthermia application was studied by exposing the prepared nanoparticles to different safe alternating magnetic fields (f = 120 kHz, H = 8, 10, and 12 kA/m). The intrinsic loss power obtained for Fe₃O₄@HA NPs was about 3.5 nHm²/kg, which is about 25-fold larger than that of obtained for commercial available Fe₃O₄ nanoparticles for biomedical applications. Good colloidal stability, biocompatibility, high heating efficacy, and targeting specificity to CD44 receptor-overexpressing cancer cells could make the Fe₃O₄@HA NPs as a promising multifunctional platform for diagnosis and therapeutic applications.

Recent Advances in Magnetite Nanoparticle Functionalization for Nanomedicine

Functionalization of nanomaterials can enhance and modulate their properties and behaviour, enabling characteristics suitable for medical applications. Magnetite (Fe3O4) nanoparticles are one of the most popular types of nanomaterials used in this field, and many technologies being already translated in clinical practice. This article makes a summary of the surface modification and functionalization approaches presented lately in the scientific literature for improving or modulating magnetite nanoparticles for their applications in nanomedicine.