Precise assembly of inside-out cell membrane camouflaged nanoparticles via bioorthogonal reactions for improving drug leads capturing.

Cell membrane camouflaged nanoparticles have been widely used in the field of drug leads discovery attribute to their unique biointerface targeting function. However, random orientation of cell membrane coating does not guarantee effective and appropriate binding of drugs to specific sites, especially when applied to intracellular regions of transmembrane proteins. Bioorthogonal reactions have been rapidly developed as a specific and reliable method for cell membrane functionalization without disturbing living biosystem. Herein, inside-out cell membrane camouflaged magnetic nanoparticles (IOCMMNPs) were accurately constructed via bioorthogonal reactions to screen small molecule inhibitors targeting intracellular tyrosine kinase domain of vascular endothelial growth factor recptor-2. Azide functionalized cell membrane acted as a platform for specific covalently coupling with alkynyl functionalized magnetic Fe3O4 nanoparticles to prepare IOCMMNPs. The inside-out orientation of cell membrane was successfully verified by immunogold staining and sialic acid quantification assay. Ultimately, two compounds, senkyunolide A and ligustilidel, were successfully captured, and their potential antiproliferative activities were further testified by pharmacological experiments. It is anticipated that the proposed inside-out cell membrane coating strategy endows tremendous versatility for engineering cell membrane camouflaged nanoparticles and promotes the development of drug leads discovery platforms.

Accurate construction of cell membrane biomimetic graphene nanodecoys via purposeful surface engineering to improve screening efficiency of active components of traditional Chinese medicine.

Biomimetic nanoengineering presents great potential in biomedical research by integrating cell membrane (CM) with functional nanoparticles. However, preparation of CM biomimetic nanomaterials for custom applications that can avoid the aggregation of nanocarriers while maintaining the biological activity of CM remains a challenge. Herein, a high-performance CM biomimetic graphene nanodecoy was fabricated via purposeful surface engineering, where polyethylene glycol (PEG) was used to modifying magnetic graphene oxide (MGO) to improve its stability in physiological solution, so as to improve the screening efficiency to active components of traditional Chinese medicine (TCM). With this strategy, the constructed PEGylated MGO (PMGO) could keep stable at least 10 days, thus improving the CM coating efficiency. Meanwhile, by taking advantage of the inherent ability of HeLa cell membrane (HM) to interact with specific ligands, HM-camouflaged PMGO showed satisfied adsorption capacity (116.2 mg/g) and selectivity. Finally, three potential active components, byakangelicol, imperatorin, and isoimperatorin, were screened from Angelica dahurica, whose potential antiproliferative activity were further validated by pharmacological studies. These results demonstrated that the purposeful surface engineering is a promising strategy for the design of efficient CM biomimetic nanomaterials, which will promote the development of active components screening in TCM.

A novel cell membrane-cloaked magnetic nanogripper with enhanced stability for drug discovery.

Cell membrane-cloaked nanotechnology has attracted increasing attention owing to its unique bionic properties, such as specific recognition and biocompatibility conferred by the integrated membrane structure and receptors. However, this technology is limited by the dissociation of the cell membrane from its carrier. Here, we report a novel type of cell membrane-cloaked modified magnetic nanoparticle with good stability in drug discovery. High α1A-adrenergic receptor (α1A-AR) expressing HEK293 cell membrane-cloaked magnetic nanogrippers (α1A/MNGs) were used as a platform for the specific targeting and binding of α1A-AR antagonists as candidate bioactive compounds from traditional Chinese medicine (TCM). Furthermore, using a dynamic covalent bonding approach, α1A/MNGs showed great stability with positive control drug recoveries of α1A/MNGs showing almost no decline after use in five adsorption-desorption cycles. Moreover, the α1A/MNGs possessed a unilamellar membrane with magnetic features and exhibited good binding capacity and selectivity. Ultimately, TCM and pharmacological studies of the bioactivity of the screened compounds confirmed the considerable targeting and binding capability of α1A/MNGs. Application of aldehyde group modification in this drug-targeting concept further improved biomaterial stability and paves the way for the development of new drug discovery strategies. More importantly, the successful application of α1A/MNGs provides new insights into methodologies to improve the integration of cell membranes with the nanoparticle platform.

Stability Designs of Cell Membrane Cloaked Magnetic Carbon Nanotubes for Improved Life Span in Screening Drug Leads.

Convenient strategies to provide natural cell membranes (CMs)-camouflaged nanomaterials with enhanced stability would prompt the advancement of CMs-coated biomimetic technology and expand the application of these emerging nanomaterials. Herein, we have developed stability-enhanced CMs-camouflaged magnetic carbon nanotubes (MCNTs) to screen drug leads from traditional Chinese medicine (TCMs) that target membrane receptors. By modifying MCNTs with N-ethyl-N'-(3-(dimethylamino)propyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS), the resulting covalent immobilized CMs-camouflaged MCNTs have improved stability, where the losing amount (20 mg g-1) was significantly decreased compared with that of the unimmobilized materials (40 mg g-1). The high expression ephrinb2/HEK293 cell lines were used to camouflage the EDC/NHS modified MCNTs (CMCNTs) to endow it with drug-screening sites. Moreover, with inherited properties from CMs, ephrinb2/HEK293 CMs-camouflaged CMCNTs possessed good binding capacity and selectivity, and three potential drug leads as mesaconine, deltaline, and 13-dehydroxyindine were screened from Aconitum carmichaeli Debx. The pharmacological assays indicated that mesaconine and 13-dehydroxyindine could inhibit cancer cell growth by targeting ephrinb2. As a result, this surface engineering method not only offers an insight into fabrication of stabilized CMs-coated nanomaterials but also inspires more brilliant work in the future and paves the way for the biomimetic functional modification of CNTs for a variety of applications.

Improved cell membrane bioaffinity sample pretreatment technique with enhanced stability for screening of potential allergenic components from traditional Chinese medicine injections.

Aiming at improving reliability and tedious analysis time in conventional cell membrane chromatography, an improved bioaffinity sample pretreatment technique with enhanced stability was developed to fast screen and extract potential allergenic components from traditional Chinese medicine injections. In this study, rat basophilic leukemia-2H3 cell membrane coated silica particles (RBL-2H3/CMCSPs) were fabricated by irreversible adsorption between the cell membrane and silica and self-fusion of the cell membrane, which could simulate drug-receptor interactions in vitro. Also, benefiting from the use of paraformaldehyde, the average recoveries of the six batches of RBL/CMCSPs were 90.2% with a relative standard deviation of less than 7.8%, showing that the stability of the materials was remarkably improved compared to materials without fixation. After the successful characterization by spectroscopic and imaging instruments, the prepared RBL-2H3/CMCSPs exhibited desirable adsorption capacity and selectivity. The RBL-2H3/CMCSPs combined with high performance liquid chromatography coupled with time of flight mass spectrometry were then successfully applied to screen and identify two potential allergenic components from huangqi injection, the allergenic activities of which were further investigated by ß-hexosaminidase release assay and histamine release assay in vitro. Overall, this work provides a good platform for the fabrication of bioaffinity sample pretreatment materials with high stability and a long lifespan, which can be a time-saving and energy-saving bioaffinity method to rapidly screen and preconcentrate target compounds from complex samples.

A novel cell membrane affinity sample pretreatment technique for recognition and preconcentration of active components from traditional Chinese medicine.

We describe a novel biomembrane affinity sample pretreatment technique to quickly screen and preconcentrate active components from traditional Chinese medicine (TCM), which adopts cell membrane coated silica particles (CMCSPs) as affinity ligands which benefit the biomembrane's ability to maximize simulation of drug-receptor interactions in vivo. In this study, the prepared CMCSPs formed by irreversible adsorption of fibroblast growth factor receptor 4 (FGFR4) cell membrane on the surface of silica were characterized using different spectroscopic and imaging instruments. Drug binding experiments showed the excellent adsorption rate and adsorption capacity of FGFR4/CMCSPs compared with non-coated silica particles. The FGFR4/CMCSPs were used as solid-phase extraction sorbents to pretreat the TCM Aconitum szechenyianum Gay. The resultant FGFR4/CMCSPs exhibited good performance. In addition, high selectivity and recognition ability of the FGFR4/CMCSPs were determined by selectivity experiments. Four alkaloid were screened and identified, one of these alkaloid, napellonine, showed favorable anti-tumor activity in preliminary pharmacological verification trials including cell proliferation and molecular docking assays. The proposed cell membrane affinity sample pretreatment method is a reliable, effective and time-saving method for fast screening and enriching active compounds and can be extended to pretreat other TCMs as leading compounds resources.

Overview of online two-dimensional liquid chromatography based on cell membrane chromatography for screening target components from traditional Chinese medicines.

Cell membrane chromatography is a simple, specific, and time-saving technique for studying drug-receptor interactions, screening of active components from complex mixtures, and quality control of traditional Chinese medicines. However, the short column life, low sensitivity, low column efficiency (so cannot resolve satisfactorily mixture of compounds), low peak capacity, and inefficient in structure identification were bottleneck in its application. Combinations of cell membrane chromatography with multidimensional chromatography such as two-dimensional liquid chromatography and high sensitivity detectors like mass have significantly reduced many of the above-mentioned shortcomings. This paper provides an overview of the current advances in online two-dimensional-based cell membrane chromatography for screening target components from traditional Chinese medicines with particular emphasis on the instrumentation, preparation of cell membrane stationary phase, advantages, and disadvantages compared to alternative approaches. The last section of the review summarizes the applications of the online two-dimensional high-performance liquid chromatography based cell membrane chromatography reported since its emergence to date (2010-June 2016).

Characterization the affinity of α1A adrenoreceptor by cell membrane chromatography with frontal analysis and stoichiometric displacement model.

As a bionic chromatographic method, cell membrane chromatography (CMC) has been used widely in screening active components in traditional Chinese medicine. Nevertheless, few studies have characterized the affinity between drug and receptor by CMC model. In this study, the alpha 1 adrenoreceptor (α1A AR) high expression CMC method, combined with frontal analysis and stoichiometric displacement model respectively, was established for characterizing the affinity of seven alkaloids binding to the α1A AR. The results indicate that the seven alkaloids have similar interaction strengths with tamsulosin hydrochloride (α1A AR antagonist) between them and α1A AR. In addition, electrostatic force is the main intermolecular forces between tamsulosin hydrochloride and seven alkaloids and α1A AR. The study provides a versatile approach for the characterization the affinity between drug and receptor by CMC model.

Simultaneous determination of camptothecin and 10-hydroxycamptothecine in the Camptotheca acuminate, its medicinal preparation and in rat plasma by liquid chromatography with fluorescence detection.

Camptotheca acuminata Decne is an important medicinal plant that contains various cytotoxic alkaloids, such as camptothecine (CPT) and 10-hydroxycamptothecine (HCPT). A rapid and sensitive liquid chromatography with fluorescence detection (LC-FLD) method for the quantification of CPT and HCPT is described. The separation was carried out on a DL-Cl8 column (4.6 × 150 mm, 5 µm), with the mobile phase of acetonitrile-sodium dihydrogen phosphate buffer (10 mm) using an gradient elution at the flow rate of 0.6 mL/min. The LC-FLD method was validated for linearity, sensitivity, accuracy and precision, and then used to determine the content of the above components. The lower detection limits of CPT and HCPT were 0.4 and 0.1 ng/mL, respectively. The precision was <1.58% and the mean recovery of the analytes was 96.0-98.6%. The LC-FLD method was successfully applied to determine CPT and HCPT in real samples including C. acuminate, HCPT injection and rat plasma.

Preparation of molecularly imprinted polymers based on magnetic nanoparticles for the selective extraction of protocatechuic acid from plant extracts.

In this study, highly selective core-shell molecularly imprinted polymers on the surface of magnetic nanoparticles were prepared using protocatechuic acid as the template molecule. The resulting magnetic molecularly imprinted polymers were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and vibrating sample magnetometry. The binding performances of the prepared materials were evaluated by static and selective adsorption. The binding isotherms were obtained for protocatechuic acid and fitted by the Langmuir isotherm model and Freundlich isotherm model. Furthermore, the resulting materials were used as the solid-phase extraction materials coupled to high-performance liquid chromatography for the selective extraction and detection of protocatechuic acid from the extracts of Homalomena occulta and Cynomorium songaricum with the recoveries in the range 86.3-102.2%.

[Chemical constituents from rizomes of Homalomena occulta].

Column chromatography on silica gel and Sephadex LH-20 was used to study the chemical constituents of Homalomena occulta. The chemical structures of the separated compounds were elucidated by spectroscopic data analyseS. Twelve compounds were obtained and identified as 5-pentylresorcinol-b-glucoside (1), protocatechuic acid (2), 4-hydroxybenzoic acid (3), vanillic acid (4), 5-hydroxymethyl-2-furancarboxylic acid (5), 2-furoic acid (6), 5-hydroxymethyl-2-furfural (7), (R) -malic acid (8), (R) -dimethyl malate (9), trimethyl 1,2,3-propanetricarboxylate (10), 4-hydroxytetrahydrofuran-2-one (11) and (1S, 2S, 4S)-p-menthane-1,2, 4-triol (12). Among them, compound 1 was a new natural product, and compounds 4-12 were isolated from the genus for the first time.

[Status and thinking of supervision and management of Chinese herbal medicine].

The article briefly introduces the status of the supervision and administration of Chinese herbal medicine, and summarizes the problems existing in the process of supervision and management. Meanwhile provides the countermeasures and suggestions of strengthening the supervision and administration of Chinese herbal medicine.

Magnetic molecularly imprinted polymer for the selective extraction of sildenafil, vardenafil and their analogs from herbal medicines.

The successfully developed magnetic molecularly imprinted polymers (MMIPs) toward six synthetic phosphodiesterase type-5 (PDE-5) inhibitors were described. Sildenafil was used as template for the preparation of MMIPs using superparamagnetic core-shell nanoparticle as supporter. The obtained MMIPs were characterized using transmission electron microscope, Fourier transform infrared, X-ray diffraction, and vibrating sample magnetometer. High performance liquid chromatography (HPLC) with diode array detector (DAD) was used for the analysis of target analytes. The application of MMIPs as selective sorbent in the cleanup of herbal medicine samples prior to HPLC offered simple sample preparation. The adsorption capacity and selectivity of prepared MMIPs and magnetic non-molecularly imprinted polymers were investigated. The binding isotherms were obtained for sildenafil and fitted by Freundlich isotherm model. Structurally similar compound of sildenafil and a reference compound protocatechuic acid were used for investing the selective recognition of MMIPs.

[Understanding of strengthen supervision and administration of herbal extracts].

The article briefly introduces the development history and status of the supervision and administration of herbal extracts, and summarizes the problems existing in the process of supervision and management. Meanwhile provides the countermeasures and suggestions of strengthening the supervision and administration of herbal extracts.

Magnetic molecularly imprinted polymer for the detection of rhaponticin in Chinese patent medicines.

The magnetic molecularly imprinted polymers (MMIPs) had been synthesized for the selective extraction and clean-up of rhaponticin in Chinese patent medicines (CPM). The MMIPs were prepared via suspension polymerization, using Fe(3)O(4) as magnetically component, rhaponticin as template molecule, acrylamide (AM) as functional monomers, styrene (St) as copolymer monomer and ethylene glycol dimethacrylate (EGDMA) as a cross-linker in dimethyl sulfoxide porogen. The obtained MMIPs were characterized using scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and vibrating sample magnetometer (VSM). High performance liquid chromatography (HPLC) was used for analysis the target analytes. The polymers were evaluated further by batch rebinding experiments. From the derived Freundlich isotherm (FI) equation their binding capacity and binding strength were determined. Structurally similar compound resveratrol and a reference compound kirenol were used for investing the selective recognition capability of MMIPs. The MMIPs were used as sorbents for selective pre-concentration of rhaponticin from CPM samples. The contents of rhaponticin for the four CPM samples were found to be 11.84, 3.35, 4.47, and 7.57µg g(-1), respectively, and the recoveries of spiked samples ranged from 77.82% to 91.00%. The prepared MMIPs could be applied to selectively pre-concentrate and determine rhaponticin in CPM samples.

Sesquiterpenoids from the rhizomes of Homalomena occulta.

Phytochemical investigation on the rhizomes of Homalomena occulta resulted in the isolation of five new sesquiterpenoids, namely cadinane-4ß,5α,10α-triol (1), 5(11)-epoxycadinane-4ß,5ß,10ß,11-tetraol (2), bullatantiol-1ß-methyl malate (3), 1ß,4ß,7α-trihydroxyeudesmane-1ß-methyl malate (6), and 1ß,4α,7-trihydroxyeudes-mane (7), together with five known sesquiterpenoids, bullatantriol (4), acetylbullatantriol (5), 1ß,4ß,7α-trihydroxyeudesmane (8), 1ß,4ß,7ß-trihydroxyeude-smane (9), and pterodontriol (10). Their structures were elucidated on the basis of spectroscopic evidences, including various 1D and 2D NMR and HR-ESI-MS. The structure of 1 was further confirmed by single-crystal X-ray diffraction analysis.