Micro-extraction of xenobiotics and biomolecules from different matrices on nanostructures

Sample preparation is the backbone of any analytical procedure; it involves extraction and pre-concentration of the desired analytes; often at trace levels. The present article describes the applications of nanomaterials (carbon-based inorganic and polymeric materials) in miniaturized extraction such as solid phase micro-extraction, stir-bar sorptive extraction, liquid phase micro-extraction, and dispersive liquid phase micro-extraction in the analyses of aqueous samples. The nanoparticles used for micro-extractions are discussed on the basis of their chemical natures. The synthetic route and the preparation of nanomaterials are described along with the optimization strategies for micro-extraction. A comparison between the conventional materials and nanomaterials for micro-extraction is proposed. The key roles of the nanomaterials for the micro-extraction of different analytes such as drugs, pesticides, polycyclic aromatic hydrocarbons, proteins and peptides from aqueous samples are reported. The use of nanomaterials, combined with miniaturized micro-extraction techniques, proved to be highly promising for sample preparation of various matrices with analytes at trace levels

Portable micro-solid phase extraction for the determination of polycyclic aromatic hydrocarbons in water samples

This work describes for the first time the application of portable micro-solid phase extraction (μ-SPE) for the determination of polycyclic aromatic hydrocarbons (PAHs). In this technique, a battery-operated electric whisk stirrer combined with a μ-SPE device was employed to provide agitation of the sample solution and facilitate the pre-concentration of the target analytes. The μ-SPE device consisted of multi-walled carbon nanotubes (MWCNTs) packed in a polypropylene (PP) membrane. The performance of μ-SPE sampling coupled with high performance liquid chromatography-ultraviolet detection (HPLC-UV) was evaluated for the analysis of five target PAHs (fluorene, anthracene, fluoranthene, pyrene and benzo[a]pyrene) in water. Important μ-SPE parameters were studied and the optimal extraction conditions were 30 min extraction time, 10 min desorption time, isopropanol as the conditioning and desorption solvent and no addition of a salt. The developed portable μ-SPE method provided good linearity in the concentration range of 0.1-100 μg L-1 for fluorene, anthracene, fluoranthene and pyrene, and 1-100 μg L-1 for benzo[a]pyrene, with good coefficients of determination (r2, 0.9975-0.9989), low limits of detection (0.01-0.59 μg L-1), acceptable intra-day precisions (3.5-6.2% for on-site analysis) and acceptable relative recoveries (77.3-107.2%). Portable μ-SPE combined with HPLC-UV was successfully applied to the determination of target PAHs in selected water samples. The proposed sample preparation technique proved to be simple, cost effective, easy-to-operate and feasible for both off-site and on-site analyses

Liquid chromatographic determination of NSAIDs in urine after dispersive liquid-liquid microextraction based on solidification of floating organic droplets

An environmentally benign method of sample preparation based on dispersive liquid–liquid microextraction and solidification of floating organic droplets (DLLME-SFO) coupled with high-performance liquid chromatography with ultraviolet detection has been developed for analysis of non-steroidal anti-inflammatory drugs (NSAIDs) in biological fluids. A low-toxicity solvent was used to replace the chlorinated solvents commonly used in conventional DLLME. Seven conditions were investigated and optimized: type and volume of extraction solvent and dispersive solvent, extraction time, effect of addition of salt, and sample pH. Under the optimum conditions, good linearity was obtained in the range 0.01–10 µg mL−1, with coefficients of determination (r2) >0.9949. Detection limits were in the range 0.0034–0.0052 µg mL−1 with good reproducibility (RSD) and satisfactory inter-day and intra-day recovery (95.7–115.6 %). The method was successfully used for analysis of diclofenac, mefenamic acid, and ketoprofen in human urine. Analysis of urine samples from a patient 2 and 4 h after administration of diclofenac revealed concentrations of 1.20 and 0.34 µg mL−1, respectively

Micro-extraction of Xenobiotics and Biomolecules from different matrices on nanostructures

Sample preparation is the backbone of any analytical procedure; it involves extraction and pre-concentration of the desired analytes; often at trace levels. The present article describes the applications of nanomaterials (carbon-based inorganic and polymeric materials) in miniaturized extraction such as solid phase micro-extraction, stir-bar sorptive extraction, liquid phase micro-extraction, and dispersive liquid phase micro-extraction in the analyses of aqueous samples. The nanoparticles used for micro-extractions are discussed on the basis of their chemical natures. The synthetic route and the preparation of nanomaterials are described along with the optimization strategies for micro-extraction. A comparison between the conventional materials and nanomaterials for micro-extraction is proposed. The key roles of the nanomaterials for the micro-extraction of different analytes such as drugs, pesticides, polycyclic aromatic hydrocarbons, proteins and peptides from aqueous samples are reported. The use of nanomaterials, combined with miniaturized micro-extraction techniques, proved to be highly promising for sample preparation of various matrices with analytes at trace levels

Emergence of mRNA vaccines in the management of cancer

Introduction mRNA vaccines have been developed as a promising cancer management. It is noted that specification of the antigen sequence of the target antigen is necessary for the design and manufacture of an mRNA vaccine. Areas covered The steps involved in preparing the mRNA-based cancer vaccines are isolation of the mRNA cancer from the target protein using the nucleic acid RNA-based vaccine, sequence construction to prepare the DNA template, in vitro transcription for protein translation from DNA into mRNA strand, 5’ cap addition and poly(A) tailing to stabilize and protect the mRNA from degradation and purification process to remove contaminants produced during preparation. Expert opinion Lipid nanoparticles, lipid/protamine/mRNA nanoparticles, and cell-penetrating peptides have been used to formulate mRNA vaccine and to ensure vaccine stability and delivery to the target site. Delivery of the vaccine to the target site will trigger adaptive and innate immune responses. Two predominant factors of the development of mRNA-based cancer vaccines are intrinsic influence and external influence. In addition, research relating to the dosage, route of administration, and cancer antigen types have been observed to positively impact the development of mRNA vaccine