Nanocomposite microbeads made of recycled polylactic acid for the magnetic solid phase extraction of xenobiotics from human urine

Nanocomposite microbeads (average diameter = 10-100 µm) were prepared by a microemulsion-solidification method and applied to the magnetic solid-phase extraction (m-SPE) of fourteen analytes, among pesticides, drugs, and hormones, from human urine samples. The microbeads, perfectly spherical in shape to maximize the surface contact with the analytes, were composed of magnetic nanoparticles dispersed in a polylactic acid (PLA) solid bulk, decorated with multi-walled carbon nanotubes (mPLA@MWCNTs). In particular, PLA was recovered from filters of smoked electronic cigarettes after an adequate cleaning protocol. A complete morphological characterization of the microbeads was performed via Fourier-transform infrared (FTIR) spectroscopy, UV-Vis spectroscopy, thermogravimetric and differential scanning calorimetry analysis (TGA and DSC), scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD). The recovery study of the m-SPE procedure showed yields ≥ 64%, with the exception of 4-chloro-2-methylphenol (57%) at the lowest spike level (3 µg L-1). The method was validated according to the main FDA guidelines for the validation of bioanalytical methods. Using liquid chromatography-tandem mass spectrometry, precision and accuracy were below 11% and 15%, respectively, and detection limits of 0.1-1.8 µg L-1. Linearity was studied in the range of interest 1-15 µg L-1 with determination coefficients greater than 0.99. In light of the obtained results, the nanocomposite microbeads have proved to be a valid and sustainable alternative to traditional sorbents, offering good analytical standards and being synthetized from recycled plastic material. One of the main objectives of the current work is to provide an innovative and optimized procedure for the recycling of a plastic waste, to obtain a regular and reliable microstructure, whose application is here presented in the field of analytical chemistry. The simplicity and greenness of the method endows the procedure with a versatile applicability in different research and industrial fields.

An introductory review on advanced multifunctional materials

This review summarizes the applications of some of the advanced materials. It included the synthesis of several nanoparticles such as metal oxide nanoparticles (e.g., Fe₃O₄, ZnO, ZrOSO₄, MoO_3-x, CuO, AgFeO₂, Co₃O₄, CeO₂, SiO₂, and CuFeO₂); metal hydroxide nanosheets (e.g., Zn₅(OH)₈(NO₃)₂·2H₂O, Zn(OH)(NO₃)·H₂O, and Zn₅(OH)₈(NO₃)₂); metallic nanoparticles (Ag, Au, Pd, and Pt); carbon-based nanomaterials (graphene, graphene oxide (GO), graphitic carbon nitride (g-C₃N₄), and carbon dots (CDs)); biopolymers (cellulose, nanocellulose, TEMPO-oxidized cellulose nanofibers (TOCNFs), and chitosan); organic polymers (e.g. covalent-organic frameworks (COFs)); and hybrid materials (e.g. metal-organic frameworks (MOFs)). Most of these materials were applied in several fields such as environmental-based technologies (e.g., water remediation, air purification, gas storage), energy (production of hydrogen, dimethyl ether, solar cells, and supercapacitors), and biomedical sectors (sensing, biosensing, cancer therapy, and drug delivery). They can be used as efficient adsorbents and catalysts to remove emerging contaminants e.g., inorganic (i.e., heavy metals) and organic (e.g., dyes, antibiotics, pesticides, and oils in water via adsorption. They can be also used as catalysts for catalytic degradation reactions such as redox reactions of pollutants. They can be used as filters for air purification by capturing carbon dioxide (CO₂) and volatile organic compounds (VOCs). They can be used for hydrogen production via water splitting, alcohol oxidation, and hydrolysis of NaBH₄. Nanomedicine for some of these materials was also included being an effective agent as an antibacterial, nanocarrier for drug delivery, and probe for biosensing.

Chitosan-CdS Quantum Dots Biohybrid for Highly Selective Interaction with Copper(II) Ions

Cadmium sulfide (CdS) quantum dots (QDs) were homogeneously embedded into chitosan (CTS), denoted as CdS@CTS, via an in situ hydrothermal method. The intact structure of the synthesized materials was preserved using freeze-drying. The materials were characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy, transmission electron microscopy, high-resolution TEM, scanning TEM, dispersive energy X-ray (EDX) for elemental analysis and mapping, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption isotherms, thermogravimetric analysis, UV-vis spectroscopy, and diffuse reflectance spectroscopy (DRS). The synthesis procedure offered CdS QDs of 1-7 nm (average particle size of 3.2 nm). The functional groups of CTS modulate the in situ growth of CdS QDs and prevent the agglomeration of CdS QDs, offering homogenous distribution inside CTS. CdS@CTS QDs can also be used for naked-eye detection of heavy metals with high selectivity toward copper (Cu²⁺) ions. The mechanism of interactions between Cu²⁺ ions and CdS@CTS QDs were further studied.

Nanoporous Substrates with Molecular-Level Perfluoroalkyl/Alkylamide Surface for Laser Desorption/Ionization Mass Spectrometry of Small Proteins

The rapid detection of biomolecules greatly contributes to health management, clinical diagnosis, and prevention of diseases. Mass spectrometry (MS) is effective for detecting and analyzing various molecules at high throughput. However, there are problems with the MS analysis of biological samples, including complicated separation operations and essential pretreatments. In this study, a nanostructured organosilica substrate for laser desorption/ionization mass spectrometry (LDI-MS) is designed and synthesized to detect peptides and small proteins efficiently and rapidly. The surface functionality of the substrate is tuned by perfluoroalkyl/alkylamide groups mixed at a molecular level. This contributes to both lowering the surface free energy and introducing weak anchoring sites for peptides and proteins. Analyte molecules applied onto the substrate are homogeneously distributed and readily desorbed by the laser irradiation. The organosilica substrate enables the efficient LDI of various compounds, including peptides, small proteins, phospholipids, and drugs. An amyloid β protein fragment, which is known as a biomarker for Alzheimer's disease, is detectable at 0.05 fmol μL^-1. The detection of the amyloid β at 0.2 fmol μL^-1 is also confirmed in the presence of blood components. Nanostructured organosilica substrates incorporating a molecular-level surface design have the potential to enable easy detection of a wide range of biomolecules.

Improvement of Transfection with PepFects Using Organic and Inorganic Materials

Cell-penetrating peptides (CPPs) are a promising non-viral vector for gene and drug delivery. CPPs exhibit high cell transfection, and are biocompatible. They can be also conjugated with organic and inorganic nanomaterials, such as magnetic nanoparticles (MNPs), graphene oxide (GO), metal-organic frameworks (MOFs), and chitosan. Nanomaterials offered a high specific surface area and provided relatively straightforward methods to be modified with biomolecules including CPPs and oligonucleotides (ONs). Novel nanomaterials conjugates with CPP/ONs complexes are therefore of interest for cell transfection with high efficiency. In this chapter, we described a summary of the non-viral vectors consisting of CPPs and nanomaterials. The book chapter also included a protocol to generate hybrid biomaterials consisting of CPPs and nanoparticles (NPs) for the delivery of oligonucleotides. The conjugation of NPs with CPPs serves as an effective platform for gene therapy with high cell transfection efficiency. The protocol is simple, offers high cell transfection compared to the CPPs-ONs complexes, and can be used for further improvements using external stimuli.

Inorganic Matrices Assisted Laser Desorption/Ionization Mass Spectrometry for Metabolic Analysis in Bio-fluids

Metabolic analysis in bio-fluids interprets the end products in the bio-process, emerging as an irreplaceable disease diagnosis and monitoring platform. Laser desorption/ionization mass spectrometry (LDI MS) based metabolic analysis exhibits great potential for clinical applications in terms of high throughput, rapid signal readout, and minimal sample preparation. There are two essential elements to construct the LDI MS-based metabolic analysis: 1) well-designed nanomaterials as matrices; 2) machine learning algorithms for data analysis. This review highlights the development of various inorganic matrices to comprehend the advantages of LDI MS in metabolite detection and the recent diagnostic applications based on target metabolite detection and untargeted metabolic fingerprints in biological fluids.

Improving anti-cancer drug delivery performance of magnetic mesoporous silica nanocarriers for more efficient colorectal cancer therapy

BACKGROUND

Improving anti-cancer drug delivery performance can be achieved through designing smart and targeted drug delivery systems (DDSs). For this aim, it is important to evaluate overexpressed biomarkers in the tumor microenvironment (TME) for optimizing DDSs.

MATERIALS AND METHODS

Herein, we designed a novel DDS based on magnetic mesoporous silica core-shell nanoparticles (SPION@MSNs) in which release of doxorubicin (DOX) at the physiologic pH was blocked with gold gatekeepers. In this platform, we conjugated heterofunctional polyethylene glycol (PEG) onto the outer surface of nanocarriers to increase their biocompatibility. At the final stage, an epithelial cell adhesion molecule (EpCAM) aptamer as an active targeting moiety was covalently attached (Apt-PEG-Au@NPs-DOX) for selective drug delivery to colorectal cancer (CRC) cells. The physicochemical properties of non-targeted and targeted nanocarriers were fully characterized. The anti-cancer activity, cellular internalization, and then the cell death mechanism of prepared nanocarriers were determined and compared in vitro. Finally, tumor inhibitory effects, biodistribution and possible side effects of the nanocarriers were evaluated in immunocompromised C57BL/6 mice bearing human HT-29 tumors.

RESULTS

Nanocarriers were successfully synthesized with a mean final size diameter of 58.22 ± 8.54 nm. Higher cytotoxicity and cellular uptake of targeted nanocarriers were shown in the EpCAM-positive HT-29 cells as compared to the EpCAM-negative CHO cells, indicating the efficacy of aptamer as a targeting agent. In vivo results in a humanized mouse model showed that targeted nanocarriers could effectively increase DOX accumulation in the tumor site, inhibit tumor growth, and reduce the adverse side effects.

CONCLUSION

These results suggest that corporation of a magnetic core, gold gatekeeper, PEG and aptamer can strongly improve drug delivery performance and provide a theranostic DDS for efficient CRC therapy.

Magnetically guided theranostics: montmorillonite-based iron/platinum nanoparticles for enhancing in situ MRI contrast and hepatocellular carcinoma treatment

In Asia, including Taiwan, malignant tumors such as Hepatocellular carcinoma (HCC) one of the liver cancer is the most diagnosed subtype. Magnetic resonance imaging (MRI) has been a typical diagnostic method for accurately diagnosing HCC. When it is difficult to demonstrate non-enhanced MRI of tumors, radiologists can use contrast agents (such as Gd3+, Fe3O4, or FePt) for T1-weighted and T2-weighted imaging remain in the liver for a long time to facilitate diagnosis via MRI. However, it is sometimes difficult for T2-weighted imaging to detect small tumor lesions because the liver tissue may absorb iron ions. This makes early cancer detection a challenging goal. This challenge has prompted current research to create novel nanocomposites for enhancing the noise-to-signal ratio of MRI. To develop a method that can more efficiently diagnose and simultaneously treat HCC during MRI examination, we designed a functionalized montmorillonite (MMT) material with a porous structure to benefit related drugs, such as mitoxantrone (MIT) delivery or as a carrier for the FePt nanoparticles (FePt NPs) to introduce cancer therapy. Multifunctional FePt@MMT can simultaneously visualize HCC by enhancing MRI signals, treating various diseases, and being used as an inducer of magnetic fluid hyperthermia (MFH). After loading the drug MIT, FePt@MMT-MIT provides both MFH treatment and chemotherapy in one nanosystem. These results ultimately prove that functionalized FePt@MMT-MIT could be integrated as a versatile drugs delivery system by combining with MRI, chemotheraeutic drugs, and magnetic guide targeting.

3D paper-based microfluidic device: a novel dual-detection platform of bisphenol A

A novel platform of 3D paper-based microfluidic device (μPADs) was fabricated by a digital plotter for high precision analysis of bisphenol A using electrochemistry along with LDI-MS detection.

A New Binary Matrix for Specific Detection of Mercury(II) Using Matrix-Assisted Laser Desorption Ionization Mass Spectrometry

The development of simple, low-cost, and specific detection method for mercury (Hg(II)) ions in aqueous media using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) is a challenge due to matrix interferences and acidity that destroy weak interactions. Herein, a new binary matrix consists of mefenamic acid, and thymine (T) is applied for simple and specific detection of Hg(II) in aqueous solution and blood sample. Mass spectra show metal-to-ligand ratio of 1:2 (Hg(II):T) in which Hg(II) ions are bound to two T molecules and two water molecules, i.e., [Hg(T)₂(H₂O)₂]. The method is simple and fast, and requires cheap reagents. In addition, the spectra show extremely specific signals for Hg(II) ions and insignificant signals in case of other competing metal ions. The concept of our protocol can be applied for other metals. The new matrix may be used for the analysis of small molecules with minimal interferences peaks.

Core-shell hollow spheres of type C@MoS2 for use in surface-assisted laser desorption/ionization time of flight mass spectrometry of small molecules

Mesoporous carbon hollow spheres coated with MoS₂ (C@MoS₂) were synthesized to obtain a material with large specific surface area, fast electron transfer efficiency and good water dispersibility. The composite material was applied as a matrix for the analysis of small molecules by surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS). The use of a core-shell C@MoS₂ matrix strongly reduces matrix background interferences and increases signal intensity in the analysis of sulfonamides antibiotics (SAs), cationic dyes, emodin, as well as estrogen and amino acids. The composite material was applied to the SALDI-TOF MS analysis of selected molecules in (spiked) real samples. The ionization mechanism of the core-shell C@MoS₂ as a matrix is discussed. The method exhibits low fragmentation interference, excellent ionization efficiency, high reproducibility and satisfactory salt tolerance. Graphical abstractSchematic representation of the method for fabrication of MoS₂-coated mesoporous carbon hollow spheres (core-shell C@MoS₂). As a new matrix, the nanocomposites were applied to analysis of small molecules by surface-assisted laser desorption/ionization time-of-flight mass spectrometry.

Synergistic Effect of Metal-Organic Framework/Gallic Acid in Enhanced Laser Desorption/Ionization Mass Spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) has become an indispensable tool for high-throughput analysis of macromolecules, but many challenges still remain in detection of small molecules due to the severe matrix-related background interference in the low-molecular-weight ranges (MW < 700 Da). Herein, a gallic acid (GA)-functionalized zirconium 1,4-dicarboxybenzene metal-organic framework (MOF) (denoted as UiO-66-GA) was designed to serve as a new substrate, and a novel strategy on the basis of the synergistic effect of MOF and GA was developed to enhance the LDI process. In comparison with conventional organic matrices, the UiO-66-GA substrate showed superior LDI performance in the analysis of a wide variety of molecules including amino acids, unsaturated fatty acids, bisphenols (BPs), oligosaccharides, peptides, protein, and polyethylene glycol (PEG) of various average molecular weights from 200 to 10000. Perfluorooctanoic sulfonate (PFOS) was used to evaluate the ability of quantitative analysis, and its corresponding limit of detection as low as 1 fmol was achieved. High sensitivity and good salt tolerance of the UiO-66-GA-assisted LDI-MS were allowed to determine ultratrace PFOS in the spiked human urine and serum samples. In addition, the synergistic mechanism of MOF and GA in the enhanced LDI process was investigated by comprehensively comparing GA- and its analogue-functionalized UiO-66, and the results revealed that two aspects contributed to the enhanced LDI process: (1) an enhancement in the metal-phenolic coordination system of UiO-66-GA promoted laser absorption and energy transfer; (2) introduction of carboxyl and hydroxyl groups of GA onto UiO-66 facilitated the LDI process in both positive and negative ion modes. This work expands a new domain for the MOF applications and provides a promising alternative for various molecule analyses.

Osteoporosis risk assessment using multilayered gold-nanoparticle thin film via SALDI-MS measurement

A powerful technique to detect bone biomarkers has been developed for assessment of osteoporosis at the early stage. Two-dimensional multilayered gold-nanoparticle thin film (MTF-AuNPs) was demonstrated as a promising test platform for detection of bone biomarker, hydroxyproline (HYP), measured by surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS). With strong surface plasmon resonance and excellent homogeneity, facilely prepared, highly ordered, and large-scale MTF-AuNPs revealed high sensitivity of HYP in the SALDI-MS measurement without additional matrixes, such as α-cyano-4-hydroxycinnamic acid (CHCA) and 2,5-dihydroxybenzoic acid (DHB). Furthermore, the mass spectrum of HYP with MTF-AuNPs was significantly improved in signal intensity enhancement, background noise reduction, and signal-to-noise ratio amplification. The excellent reproducibility of HYP spectra with only 9.3% relative signal variation could be attributed to MTF-AuNPs' high absorbance at a wavelength of 337 nm, low heat capacity, superior thermal conductivity, and outstanding homogeneity. The calibration curve showed high linear correlation between mass spectrum intensity and HYP concentration in the range of 1 to 100 μM, covering the whole level in healthy people and osteoporosis patients. In particular, the serum sample was directly deposited onto the MTF-AuNP sample substrate without any pretreatment and its HYP concentration was then successfully determined. We believe that the combination of SALDI-MS and MTF-AuNP sample substrates would be a potential approach for bone biomarker detection in the osteoporosis risk assessment. Graphical abstract.

Ionic Liquid-Assisted Laser Desorption/Ionization-Mass Spectrometry: Matrices, Microextraction, and Separation

Ionic liquids (ILs) have advanced a variety of applications, including matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). ILs can be used as matrices and solvents for analyte extraction and separation prior to analysis using laser desorption/ionization-mass spectrometry (LDI-MS). Most ILs show high stability with negligible sublimation under vacuum, provide high ionization efficiency, can be used for qualitative and quantitative analyses with and without internal standards, show high reproducibility, form homogenous spots during sampling, and offer high solvation efficiency for a wide range of analytes. Ionic liquids can be used as solvents and pseudo-stationary phases for extraction and separation of a wide range of analytes, including proteins, peptides, lipids, carbohydrates, pathogenic bacteria, and small molecules. This review article summarizes the recent advances of ILs applications using MALDI-MS. The applications of ILs as matrices, solvents, and pseudo-stationary phases, are also reviewed.