Magnetic iron oxide nanoparticles graftedN-isopropylacrylamide/chitosan copolymer for the extraction and determination of letrozole in human biological samples

Dual-stimuli-responsive carboxymethyl chitosan/sodium lignosulfonate microcapsules from oppositely charged biopolymers for smart pesticide release

In this study, we constructed a pH/laccase dual responsive drug delivery system, denoted as IMI@(CMCS+SL)n, capable of modulating wall thickness and drug release via the layer-by-layer deposition of carboxymethyl chitosan (CMCS) and sodium lignosulfonate (SL). The IMI@(CMCS+SL)n microcapsules was characterized by Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), (energy-dispersive X-ray spectroscopy) EDS, X-ray photoelectron spectroscopy (XPS), and dynamic light scattering techniques (DLS) analysis. IMI@(CMCS+SL)n demonstrated not only a high loading capacity (exceeding 90 %) but also exhibited exceptional performance in sustained release and anti-termite activity of IMI. Significantly, IMI@(CMCS+SL)n was responsive to both laccase and pH variations. These results suggest that the distinctive laccase activity and weakly alkaline conditions within the termite gut may serve as triggering factors for the release of IMI by IMI@(CMCS+SL)n. Overall, the pesticide carrier system designed in this research ensures precise pesticide application and enhances the value of natural biomass resources.

In vitro evaluation of copper sulfide nanoparticles decorated with folic acid/chitosan as a novel pH-sensitive nanocarrier for the efficient controlled targeted delivery of cytarabine as an anticancer drug

Nanoparticles (NPs) have gained more attention as drug delivery systems. Folic acid (FA)-chitosan (CS) conjugates, because of their biodegradability, low toxicity, and better stability, offer a pharmaceutical drug delivery tool. The aim of this work was to fabricate CuS NPs modified by CS followed by grafting FA as a nanocarrier for the delivery of cytarabine (CYT) as an anticancer drug. In this work, CuS NPs modified by CS and FA were successfully synthesized. The structural properties of the nanocarrier were characterized by using scanning electron microscopy, Fourier transform infrared, X-ray diffraction, thermogravimetric analysis, and Brunauer-Emmett-Teller. The adsorption mechanism of CYT by adsorption isotherms, kinetics, and thermodynamics was deliberated and modeled. The in vitro CYT release behavior for the nanocarrier was 99% and 61% at pH 5.6 and 7.4, respectively. The adsorption behavior of CYT by CuS NP_s -CS-FA was well explored by pseudo-second-order kinetic and Langmuir isotherm models by the coefficient of determination (R² > 0.99). Thermodynamic results showed that the uptake of CYT by CuS NPs-CS-FA was endothermic and spontaneous. The experimental results showed that CYT/CuS NP_s -CS-FA can be proposed as an efficient nanocarrier for the targeted delivery of anticancer drugs.

Nanomagnet-facilitated pharmaco-compatibility for cancer diagnostics: Underlying risks and the emergence of ultrasmall nanomagnets

Cancer therapy is a fast-emerging biomedical paradigm that elevates the diagnostic and therapeutic potential of a nanovector for identification, monitoring, targeting, and post-treatment response analysis. Nanovectors of superparamagnetic iron oxide nanoparticles (SPION) are of tremendous significance in cancer therapy because of their inherited high surface area, high reactivity, biocompatibility, superior contrast, and magnetic and photo-inducibility properties. In addition to a brief introduction, we summarize various progressive aspects of nanomagnets pertaining to their production with an emphasis on sustainable biomimetic approaches. Post-synthesis particulate and surface alterations in terms of pharmaco-affinity, liquid accessibility, and biocompatibility to facilitate cancer therapy are highlighted. SPION parameters including particle contrast, core-fusions, surface area, reactivity, photosensitivity, photodynamics, and photothermal properties, which facilitate diverse cancer diagnostics, are discussed. We also elaborate on the concept of magnetism to selectively focus chemotherapeutics on tumors, cell sorting, purification of bioentities, and elimination of toxins. Finally, while addressing the toxicity of nanomaterials, the advent of ultrasmall nanomagnets as a healthier alternative with superior properties and compatible cellular interactions is reviewed. In summary, these discussions spotlight the versatility and integration of multi-tasking nanomagnets and ultrasmall nanomagnets for diverse cancer theragnostics.

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SPION synthesis with ascribed prominence on sustainable procedures.

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Particulate species, composition, and surface alteration-enabled theragnostics are highlighted.

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Inherent properties of SPIONs facilitating cancer diagnostics are elaborated.

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Magnetism-based “chemotherapeutics,” cell-sorting, and bioentity purification are emphasized.

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Emergence of ultrasmall SPIONs as a healthier option is summarized.

Application of magnetic nanomaterials in bioanalysis

The importance of magnetic nanomaterials and magnetic hybrid materials, which are classified as new generation materials, in analytical applications is increasingly understood, and research on the adaptation of these materials to analytical methods has gained momentum. Development of sample preparation techniques and sensor systems using magnetic nanomaterials for the analysis of inorganic, organic and biomolecules in biological samples, which are among the samples that analytical chemists work on most, are among the priority issues. Therefore in this review, we focused on the use of magnetic nanomaterials for the bioanalytical applications including inorganic and organic species and biomolecules in different biological samples such as primarily blood, serum, plasma, tissue extracts, urine and milk. We summarized recent progresses, prevailing techniques, applied formats, and future trends in sample preparation-analysis methods and sensors based on magnetic nanomaterials (Mag-NMs). First, we provided a brief introduction of magnetic nanomaterials, especially their magnetic properties that can be utilized for bioanalytical applications. Second, we discussed the synthesis of these Mag-NMs. Third, we reviewed recent advances in bioanalytical applications of the Mag-NMs in different formats. Finally, recently literature studies on the relevance of Mag-NMs for bioanalysis applications were presented.

Electrodeposition of poly-ethylenedioxythiophene-graphene oxide nanocomposite in a stainless steel tube for solid-phase microextraction of letrozole in plasma samples

Coated stainless steel was used as an in-tube solid-phase microextraction for the extraction of letrozole from plasma samples. The coating process on the inner surface of the stainless steel was conducted by a simple electrodeposition process. The coated composite was prepared from 3,4-ethylenedioxythiophene and graphene oxide. In this composite, graphene oxide acts as an anion dopant and sorbent. The coated nanostructured polymer was characterized using different techniques. The operational factors affecting the extraction process, including pH, adsorption, and desorption time, the recycling flow rate of the sample solution, sample volume, desorption solvent type and its volume, and ionic strength were optimized to achieve the best extraction efficiency of the analyte. The total extraction time including adsorption and desorption steps was about 15.0 min. The developed method demonstrated a linear range of 5.0-1500.0 μg/L with a limit of detection of 1.0 μg/L. The repeatability of the developed extraction approach in terms of intraday, interday, and fiber to fiber was attained in the range of 4.9-8.3%. After finding the optimal conditions, the potential of the described approach for letrozole quantitation was investigated in plasma samples, and satisfactory results were obtained.

Aptamer-functionalized chitosan magnetic nanoparticles as a novel adsorbent for selective extraction of ochratoxin A

The preparation and application of aptamer-functionalized chitosan magnetic nanoparticles (Fe₃O₄@CTS@Apt nanoparticles) for selective extraction and determination ochratoxin A (OTA) were described in this study. Magnetic nanoparticle was synthesized by the coprecipitation method followed by coating with chitosan to improve its stability and biocompatibility. Further characterization was performed by scan electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and magnetic property measurement, and the results clearly indicated that the obtained magnetic chitosan nanoparticle was composed of magnetic core and chitosan coating layer. Aptamers specific to OTA were coupled onto the magnetic chitosan nanoparticles, and an extraction procedure was developed by optimization. When challenged with food samples fortified with OTA at 5 and 10 μg/kg, recoveries ranging from 91.3% to 99.1% with relative standard deviation (RSD) ≤ 4.2% were achieved by aptamer-functionalized magnetic extraction, which is very close to the results obtained by immunoaffinity chromatography extraction, indicating that this magnetic adsorbent could be hopefully used to achieve a fast and efficient extraction and detection of OTA in food samples.

Thermoresponsive chiral stationary phase functionalized with the copolymer of β-cyclodextrin and N-isopropylacrylamide for high performance liquid chromatography

A novel chiral stationary phase (CSP) was prepared through the reaction of surface-initiated atom transfer radical polymerization (ATRP) by the copolymerization of thermoresponsive N-isopropylacrylamide (NIPAM) and β-cyclodextrin (β-CD) on the silica beads for high performance liquid chromatography (HPLC). X-ray photoelectron spectroscopy (XPS), elemental analysis (EA), Fourier transform infrared spectrometry (FT-IR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were applied to characterize the surface property of modified silica. Thermoresponsive modulation for the effect on enantioselectivity were investigated with chiral reagents including 1-phenyl-1-propanol, styrene oxide, 2-phenylpropionic acid and commercial chiral drugs comprising ibuprofen and labetalol hydrochloride. The column efficiency was evaluated by chromatographic parameters including retention factor (k), selective factor (α), resolution (R_s), plate number (N) and peak tailing factor (T_f). The results showed that five chiral solutes could be separated on the prepared smart column. And the selectivity of these compounds could be modulated by regulating the column temperature. It was contributed to the thermoresponsive NIPAM assisting β-CD to separate these chiral compounds. These results indicated that the thermoresponsive CSP would be a potential tool for separation of hydrophilic and hydrophobic chiral drugs and this paper provided a novel method for chiral separation in the future.

Ultrasensitive separation of methylprednisolone acetate using a photoresponsive molecularly imprinted polymer incorporated polyester dendrimer based on magnetic nanoparticles

We developed an approach for the use of polyester dendrimer during the imprinting process to raise the number of recognized sites in the polymer matrix and improve its identification ability. Photoresponsive molecularly imprinted polymers were synthesized on modified magnetic nanoparticles involving polyester dendrimer which uses the reactivity between allyl glycidyl ether and acrylic acid for the high-yielding assembly by surface polymerization. The photoresponsive molecularly imprinted polymers were constructed using methylprednisoloneacetate as the template, water-soluble azobenzene involving 5-[(4, 3-(methacryloyloxy) phenyl) diazenyl] dihydroxy aniline as the novel functional monomer, and ethylene glycol dimethacrylate as the cross-linker. Through the evaluation of a series of features of spectroscopic and nano-structural, this sorbent showed excellent selective adsorption, recognition for the template, and provided a highly selective and sensitive strategy for determining the methylprednisoloneacetate in real and pharmaceutical samples. In addition, this sorbent according to good photo-responsive features and specific affinity to methylprednisoloneacetate with high recognition ability, represented higher binding capacity, a more extensive specific area, and faster mass transfer rate than its corresponding surface molecularly imprinted polymer.

Temperature-Responsive Magnetic Nanoparticles for Enabling Affinity Separation of Extracellular Vesicles

Small magnetic nanoparticles that have surfaces decorated with stimuli-responsive polymers can be reversibly aggregated via a stimulus, such as temperature, to enable efficient and rapid biomarker separation. To fully realize the potential of these particles, the synthesis needs to be highly reproducible and scalable to large quantity. We have developed a new synthesis for temperature-responsive magnetic nanoparticles via an in situ co-precipitation process of Fe2+/Fe3+ salts at room temperature with poly(acrylic acid)- block-poly( N-isopropylacrylamide) diblock co-polymer template, synthesized via the reversible addition-fragmentation chain-transfer polymerization method. These particles were 56% polymer by weight with a 6.5:1 Fe/COOH ratio and demonstrated remarkable stability over a 2 month period. The hydrodynamic diameter remained constant at ∼28 nm with a consistent transition temperature of 34 °C, and the magnetic particle separation efficiency at 40 °C was ≥95% over the 2 month span. These properties were maintained for all large-scale synthesis batches. To demonstrate the practical utility of the stimuli-responsive magnetic nanoparticles, the particles were incorporated into a temperature-responsive binary reagent system and efficiently separated a model protein biomarker (mouse IgG) as well as purified extracellular vesicles derived from a human biofluid, seminal plasma. The ease of using these particles will prove beneficial for various biomedical applications.

Chitosan Derivatives: Introducing New Functionalities with a Controlled Molecular Architecture for Innovative Materials

The functionalization of polymeric substances is of great interest for the development of innovative materials for advanced applications. For many decades, the functionalization of chitosan has been a convenient way to improve its properties with the aim of preparing new materials with specialized characteristics. In the present review, we summarize the latest methods for the modification and derivatization of chitin and chitosan under experimental conditions, which allow a control over the macromolecular architecture. This is because an understanding of the interdependence between chemical structure and properties is an important condition for proposing innovative materials. New advances in methods and strategies of functionalization such as the click chemistry approach, grafting onto copolymerization, coupling with cyclodextrins, and reactions in ionic liquids are discussed.