Screening and separation of natural anticancer active ingredients related to phospholipase C.

Based on the specific binding of drug molecules to cell membrane receptors, a screening and separation method for active compounds of natural products was established by combining phospholipase C (PLC) sensitized hollow fiber microscreening by a solvent seal with high-performance liquid chromatography technology. In the process, the factors affecting the screening were optimized. Under the optimal screening conditions, we screened honokiol (HK), magnolol (MG), negative control drug carbamazepine, and positive control drug amentoflavone, the repeatability of the method was tested. The PLC activity was determined before and after the screening. Experimental results showed that the sensitization factors of PLC of HK and MG were 61.0 and 48.5, respectively, and amentoflavone was 15.0, carbamazepine could not bind to PLC. Moreover, the molecular docking results were consistent with this measurement, indicating that HK and MG could be combined with PLC, and they were potential interacting components with PLC. This method used organic solvent to seal the PLC greatly ensuring the activity, so this method had the advantage of integrating separation, and purification with screening, it not only exhibited good reproducibility and high sensitivity but was also suitable for screening the active components in natural products by various targets in vitro.

Hydroxyl-rich ferrofluid for efficient liquid phase microextraction of cinnamic acid derivatives in traditional Chinese medicine.

In this study, a hydroxyl-rich ferrofluid was prepared by dispersing silica-coated magnetic nanoparticles into a methyltrioctylammonium chloride-glycerol deep eutectic solvent and then employed in the preconcentration of trace-level of cinnamic acid derivatives (caffeic acid, p-hydroxycinnamic acid, ferulic acid, and cinnamic acid) in traditional Chinese medicine prior to high-performance liquid chromatography analysis. The structures of the synthesized materials were characterized by X-ray diffraction and infrared spectroscopy. The experimental parameters affecting the extraction performance, such as deep eutectic solvent composition, dosage of ferrofluid, pH of aqueous sample solution, salt concentration, extraction time, type, and volume of desorption solvent, were studied and optimized. Under the optimum conditions, the enrichment factors of four cinnamic acid derivatives were in the range of 107-114. Low detection limits (0.2-0.9 ng/mL), good precisions (relative standard deviations 1.2%-9.5%), and satisfactory recoveries (96.0%-104.7%) were achieved. Subsequently, the possible microextraction mechanism of the proposed method was explored and elucidated. It showed that the prepared ferrofluid is easily dispersed in the aqueous sample and achieved recovery after the extraction. The developed approach is a simple, convenient, and efficient method for preconcentration and determination of cinnamic acid derivatives in complex matrices.

Application of instantaneous nebulization dispersive liquid-phase microextraction combined with HPLC for the determination of chalcone and isoflavone in traditional Chinese medicines.

A simple and rapid instantaneous nebulization dispersive liquid-phase microextraction method was developed, and combined with high-performance liquid chromatography for determination of the contents of seven analytes in traditional Chinese medicines. In this study, using the sprinkler device to achieve instantaneous synchronous dispersion and extraction, only one spray can rapidly achieve the concentration and enrichment of seven kinds of chalcone and isoflavones. The key factors affecting the extraction efficiency were optimized including the type and volume of extractant, the pH and salt concentration of the sample phase, and the number of dispersion. Under the optimal conditions, the enrichment factor of the target analytes ranged from 103.1 to 180.9, with good linearity and correlation coefficients above 0.9970. The limits of detection ranged from 0.02 to 0.15 ng/mL, with good accuracy (recoveries 91.1 to 108.9%) and precision (relative standard deviations 1.5-7.1%). This method has short extraction time (2 s), low organic solvent consumption and high enrichment effect, so it has a wide application prospects.

Effect of simulated root exudates on the distribution, bioavailability, and fractionation of potentially toxic elements (PTEs) in various particle size fractions of zinc smelting slag: Implication of direct revegetation.

Direct revegetation is a promising strategy for phytostabilization of metal smelting slag sites. Slag comes into direct contact with root exudates when slag sites undergo direct revegetation. The slag particle size fractions are considered the key factor influencing the geochemical behaviour of potentially toxic elements (PTEs). However, the effects of root exudates on the geochemical behaviours of PTEs in various slag particle size fractions remain unclear. Here, the effects of simulated root exudates of perennial ryegrass (Lolium perenne) directly revegetated at a zinc smelting slag site on the distribution, bioavailability, and fractionation of PTEs (Cu, Pb, Zn, and Cd) in various slag particle size fractions were investigated. The results showed that PTEs mainly occurred in the <1 mm slag particles; the mass loads of PTEs in the <1 mm slag particles were higher than those in the >1 mm slag particles. The bioavailability of Cu, Zn, and Cd rather than Pb in the slag increased as the particle size decreased. There was a decrease in the <0.25 and 1-2 mm slag particles and an increase in the 0.25-0.5, 0.5-1, and >2 mm slag particles in the presence of root exudates. Root exudates enhanced the transformation of acid-soluble PTEs into other more stable fractions in various slag particle size fractions. Root exudates enhanced the aggregation of slag particles associated with the migration of PTEs, causing differences in the geochemical behaviour of PTEs in various slag particle size fractions. These findings are beneficial for understanding the geochemical behaviour of PTEs in metal smelting slags undergoing direct revegetation and provide an important basis for the guidance of environmental risk management of the revegetated metal smelting slag sites.

Vertical distribution of nutrients, enzyme activities, microbial properties, and heavy metals in zinc smelting slag site revegetated with two herb species: Implications for direct revegetation.

Direct revegetation is an important measure to immobilize heavy metals and improve the microecological properties of metal smelting slag sites. However, the vertical distribution of nutrients, microecological properties, and heavy metals at a directly revegetated metal smelting slag site remains unclear. Here, the distribution characteristics of nutrients, enzyme activities, microbial properties, and heavy metals in the vertical profile at a zinc smelting slag site directly revegetated with two herb species (Lolium perenne and Trifolium repens) for 5 years were investigated. The results showed that the nutrient contents, enzyme activities, and microbial properties decreased with increasing slag depth after revegetation with the two herb species. The nutrient contents, enzyme activities, and microbial properties of the surface slag revegetated with Trifolium repens were better than those in the surface slag revegetated with Lolium perenne. The higher root activity in the surface slag (0-30 cm) resulted in relatively higher contents of pseudo-total and available heavy metals in the surface slag. Moreover, the contents of pseudo-total heavy metals (except for Zn) and available heavy metals in the slag revegetated with Trifolium repens were lower than those in the slag revegetated with Lolium perenne at most slag depths. Overall, the greater phytoremediation efficiency of the two herb species occurred mainly in the surface slag (0-30 cm), and the phytoremediation efficiency of Trifolium repens was higher than that of Lolium perenne. The findings are beneficial for understanding the phytoremediation efficiency of direct revegetation strategies for metal smelting slag sites.

Molecularly imprinted and cladded polymers for constructing a portable plasmonic immunoassay for peptides in biofluids.

Using two molecularly imprinted and cladded polymers (cMIPs), an inexpensive, fast and portable plasmonic immuno-sandwich assay (PISA) was rationally developed for high-specificity and ultra-sensitive detection of C-peptide in urine. The dual cMIPs-based PISA allowed healthy individuals to be distinguished from diabetes patients and exhibited several significant merits over existing immunoassays, holding great promise in clinical diagnosis.

Dispersive liquid-liquid microextraction based on a supramolecular solvent followed by high-performance liquid chromatographic analysis of lignans in Forsythiae Fructus.

A supramolecular solvent-based dispersive liquid-liquid microextraction was proposed for the extraction and determination of lignans in Forsythiae Fructus combined with high-performance liquid chromatography. The supramolecular solvent, consisting of tetrabutylammonium bromide and n-hexanol, was mixed with the sample solution to extract the analytes by a vortex. After accomplishing the extraction, the extraction phase was separated by centrifugation and collected for high-performance liquid chromatography analysis. In this work, the important extraction variables such as the type and amount of extraction solvent, pH and salt amount in the sample phase, and extraction time were optimized. The synthesis of supramolecular solvent was studied and its microstructure was characterized by transmission electron microscopy. Under the optimal conditions, the analytes' enrichment factors were between 6 and 170 for the proposed procedure. Satisfactory linear ranges (r ≥ 0.99), detection limits (0.025-0.4 ng/ml), precisions (< 9.2%), and accuracies (recoveries: 96.5%-104.8%) were obtained. The method has been successfully applied to the preconcentration of lignans in Forsythiae Fructus with simple and rapid operation, low cost, and environmental friendliness.

A switchable deep eutectic solvent for the homogeneous liquid-liquid microextraction of flavonoids from "Scutellariae Radix".

A homogeneous liquid-liquid microextraction (HLLME) was established based on a switchable deep eutectic solvent (DES) for the preconcentration and determination of six flavonoids with different polarity in "Scutellariae Radix" combined with high performance liquid chromatography (HPLC). A switchable DES composed of N,N-dimethylethanolamine (DMEA) and heptanoic acid was used as an extraction solvent in the HLLME method, which was miscible thoroughly with the aqueous sample phase initially, and then underwent rapid phase transition induced by the addition of an inorganic acid. After the extraction, the upper hydrophobic layer was recovered for HPLC analysis. Different experimental parameters were optimized, and the optimal extraction conditions were as follows: the switchable DES extraction phase, 90 µL of DMEA-heptanoic acid (1:1 mole ratio); phase-switching trigger, 100 µL of 5 mol/L HCl; 10% (w/v) of salt concentration in sample phase; extraction time, 0.3 min. Furthermore, the structures of the switchable DES and the upper hydrophobic layer were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance spectroscopy and differential scanning calorimetry to illustrate the phase-switching mechanism of the extraction phase during the extraction process. Under the optimized conditions, the enrichment factors for six target analytes were between 0.4 and 104. The calibration curves were linear (r≥0.9866) in the range of 0.033-8.65 mg/L for scutellarin, 0.022-5.77 mg/L for baicalin, 0.0033-0.865 mg/L for scutellarein and wogonoside, and 0.0022-0.577 mg/L for baicalein and wogonin, respectively. Low detection limits (≤8.0 × 10-3 mg/L) and quantification limits (≤2.4 × 10-2 mg/L) as well as good precisions (relative standard deviations lower than 9.2%) and acceptable accuracies (spiked recoveries 89.3-114.4%) were also obtained. The proposed method is a simple, fast, and eco-friendly sample pretreatment method.

A study on the enrichment mechanism of three nitrophenol isomers in environmental water samples by charge transfer supramolecular-mediated hollow fiber liquid-phase microextraction.

To explore the mechanism of extraction and enrichment of three nitrophenol isomers by charge-transfer supramolecular synergistic three-phase microextraction system, a charge transfer supramolecular-mediated hollow fiber liquid-phase microextraction (CTSM-HF-LPME) combined with high-performance liquid chromatography-ultraviolet detector (HPLC-UV) method was established for the determination of real environmental water samples. In this study, the three nitrophenols (NPs) formed charge-transfer supramolecules with electron-rich hollow fibers, which promoted the transport of NPs in the three-phase extraction system and greatly increased the EFs of NPs. The relationships between the EFs of NPs and their solubility, pKa, apparent partition coefficient, equilibrium constant, and structural property parameters were investigated and discussed. At the same time, most of factors affecting the EFs of NPs were investigated and optimized, such as the type of extraction solvent, pH value of sample phase and acceptor phase, extraction time, and stirring speed. Under optimal conditions, the EFs of o-nitrophenol, m-nitrophenol, and p-nitrophenol were 163, 145, and 87, respectively. With good linearity in the range of 5 × 10-7 ~ 1 µg/mL, and the limit of detection of 0.1 pg/mL, the relative standard deviations of the method precision were lower than 7.4%, and the average recoveries were between 98.6 and 106.4%. This method had good selectivity and sensitivity, satisfactory precision, and accuracy and had been successfully applied to the trace detection of real water samples.

Molecular imprinting and cladding produces antibody mimics with significantly improved affinity and specificity.

Molecularly imprinted polymers (MIPs), as important mimics of antibodies, are chemically synthesized by polymerization in the presence of a target compound. MIPs have found wide applications in important fileds. However, the current molecular imprinting technology suffers from a dilemma; there is often a compromise between the best affinity and the best specificity for MIPs prepared under optimized conditions. Herein, we proposed a new strategy called molecular imprinting and cladding (MIC) to solve this issue. The principle is straightforward; after molecular imprinting, a chemically inert cladding thinlayer is generated to precisely cover non-imprinted area. We further proposed a special MIC approach for controllably engineering protein binders. The prepared cladded MIPs (cMIPs) exhibited significantly improved affinity and specificity. The general applicability of the proposed strategy and method was verified by engineering of cMIPs for the recognition of a variety of different proteins. The feasibility of cMIPs for real applications was demonstrated by fluorescence imaging of cancer cells against normal cells and immunoassay of C-peptide in human urine. This study opened up a new avenue for controllably engineering protein-specific antibody mimics with excellent recognition properties, holding great prospective in important applications such as disease diagnosis and nanomedicine.

pH-Responsive epitope-imprinted magnetic nanoparticles for selective separation and extraction of chlorogenic acid and caffeic acid in traditional Chinese medicines.

Chlorogenic acid and caffeic acid often coexist in traditional Chinese medicines (TCMs) and play roles as antioxidation, antiviral, antitumor and anti-inflammatory agents. Due to their low content and the presence of structural analogues, they cannot be effectively separated by conventional extraction methods. Molecularly imprinted polymers, as synthesized receptors with antibody-like binding properties, have significant advantages in separating structural analogues. However, the harsh imprinting conditions easily induced the degradation of chlorogenic acid. Therefore, caffeic acid was used as an epitope template to replace chlorogenic acid for imprinting. Boronic acid-functionalized magnetic nanoparticles (MNPs) were selected as substrates, which could not only facilitate the immobilization and removal of the templates by pH regulation, but also achieve rapid separation under an external magnetic field. Tetraethyl orthosilicate was selected as an imprinting monomer which allowed for precise control of the thickness of the imprinting layer by adjusting the imprinting time. The prepared epitope-imprinted MNPs showed excellent specificity, in combination with high performance liquid chromatography, have been successfully applied to the selective separation and detection of chlorogenic acid and caffeic acid in TCMs.

Capillaries segmentation of NIR-II images and its application in ischemic stroke.

Fluorescence imaging in the second near-infrared window (NIR-II) offers µm resolution blood vessel information noninvasively, which is crucial for the diagnosis and surgery treatment of some blood vessel-related diseases. However, only a few blood vessel segmentation algorithms have been done for the NIR-II images so far. Here, we proposed a vessel segmentation algorithm that used multi-scale enhancement and fractional differential to enhance capillaries, and then segmented vessels based on the blood vessels' tubular characteristics. Experimental results showed that this method could effectively suppress the point and lump tissue noise influence during vascular segmentation. The accuracy of vessel identification by other algorithms dropped below 30%, while our algorithm still achieved an accuracy of around 50% in deep vessel segmentation experiments with the 6.5 mm Intralipid. So it had the advantage of accurately detecting deep and dim blood capillaries. Meanwhile, the vascular density quantization algorithm had been successfully applied to the mice's ischemic stroke evaluations for the first time. In addition, this algorithm can provide the quantified vessel features under physiological or pathological conditions, which could be used to accurately evaluate the stroke drugs' therapeutic effect in the future.

Preconcentration of liposoluble constituents in Salvia Miltiorrhiza using acid-assisted liquid phase microextraction based on a switchable deep eutectic solvent.

A switchable deep eutectic solvent-based liquid-phase microextraction was proposed and applied to the preconcentration and determination of liposoluble quality-markers of diterpenoid quinones (dihydrotanshinone I, cryptotanshinone, tanshinone I, and tanshinone IIA) in traditional Chinese medicine coupled with high performance liquid chromatography-ultraviolet detection. In the procedure, the hydrophilic deep eutectic solvent of diethanolamine-hexanoic acid (molar ratio 1:1) was prepared and added into the sample phase as an extractant, and a homogeneous solution was formed under slight vortex stirring. After the addition of HCl solution, the deep eutectic solvent miscible with the sample phase was converted to hydrophobic form, and a cloudy solution was generated. Then, the upper hydrophobic layer enriching the target analytes was collected through centrifugation for high performance liquid chromatography analysis. Several critical parameters affecting the extraction performance including the composition and consumption of switchable deep eutectic solvent, the type and amount of acid, salt amount and extraction time were investigated and optimized. Moreover, the structures of the deep eutectic solvent and the recovered hydrophobic layer were both characterized using Fourier transform infrared spectroscopy, further demonstrating the switching mechanism of the extractant during the extraction process. Under the optimal conditions, enrichment factors of diterpenoid quinones ranged from 59 to 274. Good linearities (r≥0.9963), low detection limits (0.5-0.7 ng/mL), satisfactory precisions (relative standard deviations 0.5%-8.6%) and accuracies (recoveries 94.6%-104.6%) were also obtained. Comparing the proposed switchable deep eutectic solvent-based liquid-phase microextraction with other published methods, the characteristics of the procedure were summarized. The developed method was successfully applied for the preconcentration of four liposoluble diterpenoid quinones from a traditional Chinese herbal medicine of Salvia Miltiorrhiza.

Controllable Engineering and Functionalizing of Nanoparticles for Targeting Specific Proteins towards Biomedical Applications.

Nanoparticles have been widely used in important biomedical applications such as imaging, drug delivery, and disease therapy, in which targeting toward specific proteins is often essential. However, current targeting strategies mainly rely on surface modification with bioligands, which not only often fail to provide desired properties but also remain challenging. Here an unprecedented approach is reported, called reverse microemulsion-confined epitope-oriented surface imprinting and cladding (ROSIC), for facile, versatile, and controllable engineering coreless and core/shell nanoparticles with tunable monodispersed size as well as specific targeting capability toward proteins and peptides. Via engineering coreless imprinted and cladded silica nanoparticles, the effectiveness and superiority over conventional imprinting of the proposed approach are first verified. The prepared nanoparticles exhibit both high specificity and high affinity. Using quantum dots, superparamagnetic nanoparticles, silver nanoparticles, and upconverting nanoparticles as a representative set of core substrates, a variety of imprinted and cladded single-core/shell nanoparticles are then successfully prepared. Finally, using imprinted and cladded fluorescent nanoparticles as probes, in vitro targeted imaging of triple-negative breast cancer (TNBC) cells and in vivo targeted imaging of TNBC-bearing mice are achieved. This approach opens a new avenue to engineering of nanoparticles for targeting specific proteins, holding great prospects in biomedical applications.

Neurovascular protection of salvianolic acid B and ginsenoside Rg1 combination against acute ischemic stroke in rats.

Ischemic stroke continues to be a major global health problem associated with considerable mortality and morbidity. Thus, it is still targeted by researchers for developing new strategies or drugs to alleviate the lesion of stroke. In the present study, both the permanent occlusion of the middle cerebral artery (MCAO) model and the restoration of cerebral blood flow after middle cerebral artery occlusion (CI/R) model were set up for evaluating the efficiency of salvianolic acid B and ginsenoside Rg1 combination (SalB-Rg1). SalB-Rg1 decreased infarct area through 3,5-triphenyltetrazolium chloride stain and improved neurological behavior through Longa Score or Left-Biased Swings on both MCAO rats and CI/R rats. Neural protection of SalB-Rg1 against ischemia or ischemic reperfusion injury was evidenced by the inhibition of nucleus pyknosis, liquefaction necrosis through H&E stain and Nissl stain. Furthermore, protection of SalB-Rg1 on blood-brain barrier (BBB) was more significant on CI/R rats, accompanying with the downregulation of matrix metalloproteinase-2 and matrix metalloproteinase-9, and recovery of zonula occludens-1 expression. These results provide compelling evidence that SalB-Rg1 holds the potential to be developed as an optimal therapeutic strategy to alleviate the injury of ischemia or ischemic reperfusion.

Efficient Screening of Glycan-Specific Aptamers Using a Glycosylated Peptide as a Scaffold.

Abnormal glycan structures are valuable biomarkers for disease states; the development of glycan-specific binders is thereby significantly important. However, the structural homology and weak immunogenicity of glycans pose major hurdles in the evolution of antibodies, while the poor availability of complex glycans also has extremely hindered the selection of anti-glycan aptamers. Herein, we present a new approach to efficiently screen aptamers toward specific glycans with a complex structure, using a glycosylated peptide as a scaffold. In this method, using peptide-imprinted magnetic nanoparticles (MNPs) as a versatile platform, a glycopeptide tryptically digested from a native glycoprotein was selectively entrapped for positive selection, while a nonglycosylated analogue with an identical peptide sequence was synthesized for negative selection. Alternating positive and negative selection steps were carried out to guide the directed evolution of glycan-binding aptamers. As proof of the principle, the biantennary digalactosylated disialylated N-glycan A2G2S2, against which there have been no antibodies and lectins so far, was employed as the target. With the glycoprotein transferrin as a source of target glycan, two satisfied anti-A2G2S2 aptamers were selected within seven rounds. Since A2G2S2 is upregulated in cancerous liver cells, carboxyfluorescein (FAM)-labeled aptamers were prepared as fluorescent imaging reagents, and successful differentiation of cancerous liver cells over normal liver cells was achieved, which demonstrated the application feasibility of the selected aptamers. This approach obviated a tedious glycan preparation process and allowed favorable expose of the intrinsic flexible conformation of natural glycans. Therefore, it holds great promise for developing glycan-specific aptamers for challenging applications such as cancer targeting.

Epitope-Imprinted Magnetic Nanoparticles as a General Platform for Efficient In Vitro Evolution of Protein-Binding Aptamers.

Aptamers are usually created by in vitro selection using a strategy termed systematic evolution of ligands by exponential enrichment (SELEX). Although numerous SELEX alternatives with improved selection efficiency have been developed, the overall success rate of SELEX at present is still not very ideal, which remains a great obstacle to aptamer-based research and application. In this study, an efficient and facile SELEX method was developed for in vitro screening of protein-binding aptamers, applying epitope-imprinted magnetic nanoparticles (MNPs) that exhibit highly favorable binding properties as a general affinity platform. As a proof of the principle, myoglobin (Mb) and ß2-microglobulin were employed as two target proteins. Two satisfied aptamers toward each target protein, with the dissociation constant at the 10-8 M level and cross-reactivity less than 16.5%, were selected within three rounds, taking only 1 day. A dual aptamer-based fluorescence sandwich assay was constructed using a pair of the selected aptamers. The resulting assay allowed for quantitatively detecting Mb in human serum and distinguishing acute myocardial infarction patients from healthy individuals. The epitope-imprinted MNP-based SELEX is straightforward and generally applicable for a wide range of target proteins, providing a promising aptamer selection tool for aptamer-based research and real-world applications.

Orthogonal dual molecularly imprinted polymer-based plasmonic immunosandwich assay: A double characteristic recognition strategy for specific detection of glycoproteins.

Sensitive and specific detection methods are critical to the detection of glycoproteins. Immunoassay has been a powerful tool for this purpose, in which antibodies or their mimics particularly molecularly imprinted polymers (MIPs) are used for specific recognition. Epitope and glycan are two structure features of a glycoprotein. However, immunoassays based on simultaneous recognition towards the two characteristics have been scarcely explored so far. Herein we present a new strategy called orthogonal dual molecularly imprinted polymer-based plasmonic immunosandwich assay (odMIP-PISA). It relies on double recognition towards a target glycoprotein by two different types of MIPs, using epitope-imprinted gold nanoparticles (AuNPs)-coated slide as capturing substrate to recognize the peptide epitope and glycans-imprinted Raman-active silver nanoparticles as labeling nanotags to recognize the glycans. Carcinoembryonic antigen (CEA), a routinely used marker for colon cancer, was used as a test glycoprotein. The orthogonal double recognition apparently improved the specificity, reducing the maximum cross-reactivity from 14.4% for epitope recognition and 15.2% for glycan recognition to 8.2% for double recognition. Meanwhile, the plasmonic nanostructure-based Raman detection provided ultrahigh sensitivity, yielding a limit of detection of 5.56 × 10-14 M (S/N = 10). Through measuring the CEA level in human serum, this method permitted differentiation of colon cancer patient from healthy individual. Compared with the traditional immunoassay, odMIP-PISA exhibited multiple advantages, including simplified procedure (6 steps), speed (30 min), reduced cost, and so on. Therefore, this new approach holds great promise in many applications particularly clinical diagnosis.

Dual Molecularly Imprinted Polymer-Based Plasmonic Immunosandwich Assay for the Specific and Sensitive Detection of Protein Biomarkers.

Molecularly imprinted polymers (MIPs), which are synthesized in the presence of a template, have been widely used as antibody mimics for important applications. Through the combination with a highly sensitive detection scheme such as chemiluminescence and surface-enhanced Raman scattering (SERS), MIP-based sandwich assays have emerged as promising analytical tools for the detection of disease biomarkers. However, so far, MIPs have been used only as target-capturing probes, whereas labeling by other means was needed, which limits the application range. Herein, we present a new approach, called a dual MIP-based plasmonic immunosandwich assay (duMIP-PISA), for the specific and sensitive detection of protein biomarkers in complex biological samples. A C-terminal epitope-imprinted self-assembled gold nanoparticle monolayer-coated glass slide was prepared as a plasmonic substrate for the specific extraction of target protein, while N-terminal epitope-imprinted Raman-responsive Ag@SiO2 nanoparticles were prepared as nanotags for the specific labeling of captured protein. The formed MIP-protein-MIP sandwich-like complexes could produce a significantly enhanced SERS signal. The dual MIP-based recognitions ensured high specificity of the assay, while SERS detection provided ultrahigh sensitivity. The duMIP-PISA of neuron-specific enolase (NSE) in human serums was demonstrated, which permitted the differentiation of small cell lung cancer patients from healthy individuals. As compared to regular ELISA, the duMIP-PISA exhibited multiple merits including a simpler procedure, faster speed, lower sample volume requirement, and wider linear range. The approach well demonstrated the great potentials of MIPs and can be easily modified and extended to other protein biomarkers. Therefore, the duMIP-PISA approach holds great promise in many important applications such as disease diagnosis.

Inhibition of HER2-Positive Breast Cancer Growth by Blocking the HER2 Signaling Pathway with HER2-Glycan-Imprinted Nanoparticles.

Blocking the HER2 signaling pathway has been an effective strategy in the treatment of HER2-positive breast cancer. It mainly relies on the use of monoclonal antibodies and tyrosine-kinase inhibitors. Herein, we present a new strategy, the nano molecularly imprinted polymer (nanoMIP). The nanoMIPs, imprinted using HER2 N-glycans, could bind almost all HER2 glycans and suppress the dimerization of HER2 with other HER family members, blocking the downstream signaling pathways, thereby inhibiting HER2+ breast cancer growth. In vitro experiments demonstrated that the nanoMIPs specifically targeted HER2+ cells and inhibited cell proliferation by 30 %. In vivo experiments indicated that the mean tumor volume of the nanoMIP-treated group was only about half of that of the non-treated groups. This study provides not only a new possibility to treat of HER2+ breast cancer but also new evidence to boost further development of nanoMIPs for cancer therapy.