Separation and purification of thymopentin with molecular imprinting membrane by solid phase extraction disks

Green Chemistry and Molecularly Imprinted Membranes

Technological progress has made chemistry assume a role of primary importance in our daily life. However, the worsening of the level of environmental pollution is increasingly leading to the realization of more eco-friendly chemical processes due to the advent of green chemistry. The challenge of green chemistry is to produce more and better while consuming and rejecting less. It represents a profitable approach to address environmental problems and the new demands of industrial competitiveness. The concept of green chemistry finds application in several material syntheses such as organic, inorganic, and coordination materials and nanomaterials. One of the different goals pursued in the field of materials science is the application of GC for producing sustainable green polymers and membranes. In this context, extremely relevant is the application of green chemistry in the production of imprinted materials by means of its combination with molecular imprinting technology. Referring to this issue, in the present review, the application of the concept of green chemistry in the production of polymeric materials is discussed. In addition, the principles of green molecular imprinting as well as their application in developing greenificated, imprinted polymers and membranes are presented. In particular, green actions (e.g., the use of harmless chemicals, natural polymers, ultrasound-assisted synthesis and extraction, supercritical CO2, etc.) characterizing the imprinting and the post-imprinting process for producing green molecularly imprinted membranes are highlighted.

The Use of Computational Methods for the Development of Molecularly Imprinted Polymers

Recent years have witnessed a dramatic increase in the use of theoretical and computational approaches in the study and development of molecular imprinting systems. These tools are being used to either improve understanding of the mechanisms underlying the function of molecular imprinting systems or for the design of new systems. Here, we present an overview of the literature describing the application of theoretical and computational techniques to the different stages of the molecular imprinting process (pre-polymerization mixture, polymerization process and ligand-molecularly imprinted polymer rebinding), along with an analysis of trends within and the current status of this aspect of the molecular imprinting field.

Multi-Interactions in Ionic Liquids for Natural Product Extraction

Natural products with a variety of pharmacological effects are important sources for commercial drugs, and it is very crucial to develop effective techniques to selectively extract and isolate bioactive natural components from the plants against the background of sustainable development. Ionic liquids (ILs) are a kind of designable material with unique physicochemical properties, including good thermal stability, negligible vapor pressure, good solvation ability, etc. ILs have already been used in pharmaceuticals for extraction, purification, drug delivery, etc. It has been reported that multi-interactions, like hydrogen bonding, hydrophobic interactions, play important roles in the extraction of bioactive components from the plants. In this review, recent progress in the understanding of scientific essence of hydrogen bonding, the special interaction, in ILs was summarized. The extraction of various natural products, one important area in pharmaceutical, by conventional and functional ILs as well as the specific roles of multi-interactions in this process were also reviewed. Moreover, problems existing in bioactive compound extraction by ILs and the future developing trends of this area are given, which might be helpful for scientists, especially beginners, in this field.

Preparation of lysozyme-imprinted nanoparticles on polydopamine-modified titanium dioxide using ionic liquid as a stabilizer

Molecular imprinting of proteins has evolved into an efficient approach for protein recognition and separation. However, maintaining the structural stability of proteins during the preparation process of molecularly imprinted polymers (MIPs) remains challenging. Ionic liquids (ILs), being capable of maintaining the stability of proteins, might enable effective imprinting and accurate recognition of proteins. In this study, lysozyme (Lyz)-imprinted titanium dioxide (TiO₂) nanoparticles, TiO₂@Lyz-MIPs, have been successfully prepared for selective recognition and separation of Lyz. This was achieved by the free radical polymerization of hydroxyethyl acrylate (HEA) and poly(ethylene glycol) dimethacrylate (PEGDMA) on polydopamine (PDA)-modified TiO₂ nanoparticles using an IL, choline dihydrogen phosphate (chol dhp), as the stabilizer of Lyz. It was found that both PDA modification of TiO₂ and the use of chol dhp as stabilizer improved the adsorption capacity of TiO₂@Lyz-MIPs toward Lyz. When the concentration of HEA was 7 mg mL⁻¹, the ratio of monomer to crosslinker was 20 : 1, and the concentration of chol dhp was 12.5 mg mL⁻¹, the highest imprinting factor of 4.40 was achieved. TiO₂@Lyz-MIPs exhibited relatively high adsorption capacity with the maximum adsorption capacity up to 120 mg g⁻¹, which was more than four times higher than that of the non-imprinted polymers (NIPs) counterpart, TiO₂@Lyz-NIPs. The adsorption rate of Lyz by TiO₂@Lyz-MIPs was also much higher than that of TiO₂@Lyz-NIPs. TiO₂@Lyz-MIPs could successfully separate Lyz from diluted egg white, a complex mixture of proteins. Findings from this study indicate that effective recognition cavities toward Lyz were formed on the surface of Lyz-imprinted TiO₂ nanoparticles prepared using IL as the template stabilizer. This approach may facilitate the development of MIPs for efficient protein recognition and separation.

Molecular imprinting of proteins has evolved into an efficient approach for protein recognition and separation.

Disk solid-phase extraction of multi-class pharmaceutical residues in tap water and hospital wastewater, prior to ultra-performance liquid chromatographic-tandem mass spectrometry (UPLC-MS/MS) analyses

In this work, a new clean-up and pre-concentration method based on disk solid-phase extraction (SPE) was developed to determine multi-class pharmaceutical residues covering a wide range of polarities (log K ow values from -0.5 to 5.1) in water systems, prior to ultra-performance liquid chromatographic-tandem mass spectrometry (UPLC-MS/MS) analyses. Electrospray ionisation in positive and negative modes was used for the simultaneous determination of both acidic and basic pharmaceuticals. The performances of disk SPE and cartridge SPE were compared. The targeted pharmaceutical compounds list included bronchodilators, antidiabetic drugs, antihypertensive drugs, a lipid-lowering agent, analgesics, and anti-inflammatory drugs. Based on our results, the disk SPE demonstrated a higher sensitivity and recovery value and less analysis time as compared to the cartridge SPE method. The limits of detection (LOD) for the new method ranged from 0.02-3.2 ng L-1, 0.02-3.1 ng L-1 and 0.02-4.7 ng L-1 for tap, effluent and influent wastewater, respectively. The method's absolute recovery values ranged from 70% to 122% for tap water, 62% to 121% for effluent wastewater and 62% to 121% for influent wastewater, except for metformin in which the absolute recovery value was approximately 48% for all samples. Intra-day precision for tap water, effluent and influent wastewater ranged from 3-12%, 4-9% and 2-8%, respectively. The method developed was applied for the determination of targeted pharmaceuticals in tap, effluent, and influent wastewater from one hospital treatment plant in Malaysia. The results revealed that the highest concentrations of certain pharmaceuticals were up to 49 424 ng L-1 (acetaminophen) and 1763 ng L-1 (caffeine) in the influent and effluent wastewater, respectively. The results also showed a variation in the treatment efficiencies for the hospital treatment plant from one compound to another. Nevertheless, the removal efficiencies ranged from 0-99%.

Highly efficient extraction of lead ions from smelting wastewater, slag and contaminated soil by two-dimensional montmorillonite-based surface ion imprinted polymer absorbent

The rapid, efficient and selective extraction of heavy metal ions is significant for wastewater pretreatment and metal ion recycle. Using montmorillonite as the template substrate and Pb²⁺ as template ions, a novel two-dimensional montmorillonite-based surface ion imprinted polymer (IIP-MMT) adsorbent is successfully synthesized via activators generated by electron transfer for atom transfer radical polymerization (AGET-ATRP). Batch adsorption experiments are performed to assess the properties of the imprinted polymer sorbent, along with its selectivity and reusability in practical extraction of Pb²⁺. It is interesting that the crosslinking density of the imprinted polymer has impact on the sorption property, where suitable density is coupled with the highest adsorption capacity and the best selectivity. Benefiting from the surface-imprinting technique and AGET-ATRP, IIP2-MMT is proved to own a highly effective Pb²⁺ adsorption capacity to reach 158.68 mg/g within 30 min, where the corresponding maximum adsorption capacity is 201.84 mg/g. Moreover, this material exhibits satisfactory stability and reusability that the high adsorptive capability of IIP-MMT retains more than 95% after six cycles. Thus, it is expected to reduce the wastewater disposal expenses. Besides, owing to the characteristics of PHEMA brushes and SHA chelating ligand, IIP-MMT has strong anti-interference and anti-blockage abilities to extract Pb²⁺ from smelting wastewater, slag and contaminated soil. Considering the low cost, excellent stability, high extraction efficiency, environmental friendliness, it is expected that the proposed material is very promising for treatment of heavy metals-contaminated wastewaters and soil, or ion recycle.

Trypsin electrochemical sensing using two-dimensional molecularly imprinted polymers on 96-well microplates

Molecular imprinting is an efficient technology to create artificial receptors with antibody-like binding properties for a variety of applications such as separation and sensing. In this work, a new sensing method was introduced by combining a two-dimensional molecularly imprinted polymer (2D-MIP) film with copper oxide nanoparticles (CuO NPs) labeling for signal conversion and amplification. CuO labeling can effectively monitor the thickness of 2D-MIPs to achieve the best imprinting effect. Trypsin imprinted polymer based electrochemical sensor on 96-well microplates was constructed and a good dynamic response was observed in the range of 0.5-500 ng/mL. Furthermore, detections of trypsin in fetal bovine serum were demonstrated using the imprinted polymer thin films. Our electrochemical sensors possess an excellent specificity, fast kinetics, high sensitivity and low cost, which have great potential in biological analysis.

Recent advances in green reagents for molecularly imprinted polymers

Molecularly imprinted polymers (MIPs) are tailor-made materials with special binding sites.

Effect of Polypeptides on Cell Proliferation and Apoptosis during Aging

Polypeptide complexes derived from the bronchi, blood vessels, muscles, kidneys, ovaries, testes, and retina stimulated the processes of cell renewal in organotypic cultures of the corresponding organs of young and old animals. A correlation between the intensity of regeneration and animal' age was revealed. The polypeptide complexes reduced the expression of apoptotic factors p53 and caspase 3 and increased the expression of proliferation protein Ki-67. These results provide the basis for further study of the polypeptide complexes as stimulators of regenerative processes in different tissues during ageing.

Fouling Resistant CA/PVA/TiO2 Imprinted Membranes for Selective Recognition and Separation Salicylic Acid from Waste Water

Highly selective cellulose acetate (CA)/poly (vinyl alcohol) (PVA)/titanium dioxide (TiO₂) imprinted membranes were synthesized by phase inversion and dip coating technique. The CA blend imprinted membrane was synthesized by phase inversion technique with CA as membrane matrix, polyethyleneimine (PEI) as the functional polymer, and the salicylic acid (SA) as the template molecule. The CA/PVA/TiO₂ imprinted membranes were synthesized by dip coating of CA blend imprinted membrane in PVA and different concentration (0.05, 0.1, 0.2, 0.4 wt %) of TiO₂ nanoparticles aqueous solution. The SEM analysis showed that the surface morphology of membrane was strongly influenced by the concentration of TiO₂ nanoparticles. Compared with CA/PVA-TiO₂(0.05, 0.1, 0.2%)-MIM, the CA/PVA-TiO₂(0.4%)-MIM possessed higher membrane flux, kinetic equilibrium adsorption amount, binding capacity and better selectivity for SA. It was found that the pseudo-second-order kinetic model was studied to describe the kinetic of CA/PVA-TiO₂(0.2%)-MIM judging by multiple regression analysis. Adsorption isotherm analysis indicated that the maximum adsorption capacity for SA were 24.43 mg g^-1. Moreover, the selectivity coefficients of CA/PVA-TiO₂ (0.2%)-MIM for SA relative to p-hydroxybenzoic acid (p-HB) and methyl salicylate (MS) were 3.87 and 3.55, respectively.