Metal organic framework- modified monolithic column immobilized with pepsin for enantioseparation in capillary electrochromatography.

Metal-organic frameworks (MOFs), defined as a class of microporous hybrid materials, are established by coordination of metal cations with functional organic ligands. In addition to outstanding porosity and large surface area, the structures and functions of MOFs can be designed and adjusted based on different destinations, which would be employed as stationary phases in various chromatographic modes. Pepsin, a class of protein, has been investigated as chiral selector owing to their unique interactions with analytes based on chiral or affinity selectivity. In this work, MOF-5 was exploited to grow on the support of poly (glycidyl methacrylate)-co-(ethylene dimethacrylate) [poly(GMA-co-EDMA)] monoliths by layer-by-layer self-assembly method. Pepsin was subsequently bonded with the carboxyl group of MOF-5 through amidation reaction. The ultimate pepsin@MOF-5@poly(GMA-co-EDMA) column was applied for enantioseparation of six basic chiral drugs by capillary electrochromatography with good resolution and repeatability. Compared with the pepsin modified monolithic column, the newly prepared column with MOF-5 shows significantly enhanced enantiomeric resolution, which reveals that MOFs-modified capillary monolithic columns lead a promising road to separation of racemates by chromatography.

Immobilization of cellulase on monolith supported with Zr(IV)-based metal-organic framework as chiral stationary phase for enantioseparation of five basic drugs in capillary electrochromatography.

Metal-organic framework (UiO-66-NH2)-incorporated organic polymer monolith was prepared by thermal polymerization. By virtue of the superior physical and chemical properties, the UiO-66-NH2-modified organic monolith was then functionalized by chiral selector cellulase via the condensation reaction between the primary amino groups and aldehyde groups. The synthesized materials were characterized by Fourier transform infrared spectroscopy, high-resolution transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectrometry, thermogravimetric analysis, and nitrogen sorption isotherm. The cellulase@poly(glycidyl methacrylate-UiO-66-NH2-ethylene glycol dimethacrylate) (cellulase@poly(GMA-UiO-66-NH2-EDMA)) monolith was applied to enantiomerically separate the basic racemic forms of metoprolol, atenolol, esmolol, bisoprolol, and propranolol. In contrast to the cellulase@poly(GMA-co-EDMA) monolith without UiO-66-NH2, the cellulase@poly(GMA-UiO-66-NH2-EDMA) monolith reveals significantly improved enantiodiscrimination performance for metoprolol (Rs: 0 → 1.67), atenolol (Rs: 0 → 1.50), esmolol (Rs: 0 → 1.52), bisoprolol (Rs: 0 → 0.36), and propranolol (Rs: 0 → 0.44). The immobilization pH of cellulase, buffer pH, UiO-66-NH2 concentration, and the proportion of organic modifier were evaluated in detail with enantiomerically separating chiral molecules. The intra-day, inter-day, column-to-column, and inter-batch precision have been discussed, the result was preferable, and the relative standard deviation (RSD) of separation parameters was <4.3%. Schematic representation of the preparation of a UiO-66-NH2-modified organic polymer monolith for enantioseparating five racemic ß-blockers. UiO-66-NH2 was synthesized and converted into a monolith as the stationary phase. Then, the modified monolith containing cellulase as the chiral selector was applied in a capillary electrochromatography system for enantioseparating chiral drugs.

[Analysis on application value of Fu's subcutaneous needling for intercostal pain after surgery of osteoporotic thoracic vertebral compression fracture].

OBJECTIVE: To observe the effect of Fu's subcutaneous needling therapy on pain degree, quality of life, serum 5-hydroxytryptamine (5-HT) and neuropeptide Y (NPY) in patients with intercostal pain after surgery for osteoporotic thoracic vertebral compression fracture (OVCF) and explore the application value of Fu's subcutaneous needling in treatment of post-operative intercostal pain. METHODS: A total of 60 patients with intercostal pain after OVCF surgery were divided into a medication group and a Fu's subcutaneous needling therapy group, with 30 cases in each group. In the medication group, zoledronic acid injection, salmon calcitonin injection, calcitonin D tablets and mecobalamin tablets were prescribed. The duration of treatment was 8 weeks. In the Fu's subcutaneous needling therapy group, on the base of treatment as the medicine group, Fu's subcutaneous needling therapy was provided for 2 weeks，once every other day. The needle is inserted 6 cm away from the most painful point. Separately, in 2, 4 and 8 weeks of treatment, as well as in 16 weeks after treatment, the visual analogue scale (VAS) and the generic quality of life inventory-74 (GQOLI-74) were adopted to evaluate intercostal pain and quality of life in the patients of both groups and analyze the incidence of adverse reaction. Radioimmunoassay was used to measure the levels of serum 5-HT and NPY. RESULTS: Compared with the results before treatment, in 2, 4 and 8 weeks of treatment as well as in 16 weeks after treatment, VAS scores of both groups were all reduced (P<0.05), GQOLI-74 scores increased obviously (P<0.05) and the levels of serum 5-HT and NPY increased obviously (P<0.05) in the two groups. In 2, 4 and 8 weeks of treatment as well as in 16 weeks after treatment, VAS score in the Fu's subcutaneous needling therapy group was lower than that in the medication group (P<0.05), GQOLI-74 score and the levels of serum 5-HT and NPY were higher than those in the medication group (P<0.05). During the treatment and in 16 weeks after treatment, the difference was not significant in the incidence of adverse reaction between the two groups (P>0.05). CONCLUSION: Fu's subcutaneous needling therapy can relieve intercostal pain and improves the quality of life in the patients after surgery for OVCF.

Colorimetric recognition of aromatic amino acid enantiomers by gluconic acid-capped gold nanoparticles.

In this work, we prepared gold nanoparticles (AuNPs) by employing gluconic acid (GlcA) as reducing-cum-stabilizing agent. The proposed GlcA-AuNPs successfully worked as a colorimetric sensor for visual chiral recognition of aromatic amino acid enantiomers, namely tyrosine (D/L-Tyr), phenylalanine (D/L-Phe), and tryptophan (D/L-Trp). After adding L-types to GlcA-AuNPs solution, the color of the mixture changed from red to purple (or gray), while no obvious color change occurred on the addition of D-types. The effect can be detected by naked eyes. The particles have been characterized by transmission electron microscopy, Fourier-transform infrared spectroscopy, zeta potential, the dynamic light scattering analysis as well as UV-Vis spectroscopy. This assay can be used to determine the enantiomeric excess of L-Trp in the range from 0 to + 100%. The method has advantages in simplicity, sensitivity, fast response, and low cost.

ß-Cyclodextrin covalent organic framework-modified organic polymer monolith as a stationary phase for combined hydrophilic and hydrophobic aqueous capillary electrochromatographic separation of small molecules.

A ß-Cyclodextrin covalent organic framework (ß-CD COF) was successfully prepared under ambient temperature with a mild chemistry strategy from heptakis(6-amino-6-deoxy)-ß-cyclodextrin and terephthalaldehyde. It was embedded into the poly[(glycidyl methacrylate)-co-(ethylene dimethacrylate)] [poly(GMA-co-EDMA)] monolith and served as the ß-CD COF material-incorporated monolith. The synthetic materials were characterized by field emission scanning electron microscopy, energy-dispersive X-ray mapping analysis, transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and N2 adsorption-desorption isotherm. The ß-CD COF material-incorporated monolith achieved baseline separation in capillary electrochromatographic separation of three amides, three amino acids, three nucleosides, four aromatic acids, and three positional isomers (with resolution values of three amides, 1.75 and 1.54; three amino acids, 5.24 and 1.75; three nucleosides, 2.56 and 1.77; four aromatic acids, 6.96, 2.74, and 1.64; three positional isomers, 1.61 and 1.50). In comparison with the original monolith, the ß-CD COF material-incorporated monolith shows significantly enhanced resolution for mixed molecules. The effect of pH and concentration of buffer and applied voltage were discussed in detail. The fabricated monolith showed good stability and reproducibility (relative standard deviation (RSD) < 6.9%). Molecular modeling illuminated the interactions between the small molecules and stationary phase, and provided a sufficient theoretical basis for experimental data. Graphical abstract Schematic presentation of the preparation of ß-cyclodextrin covalent organic framework (ß-CD COF) material-incorporated organic polymer monolith for separating the amides, amino acids, nucleosides, aromatic acids, and positional isomers. ß-CD COF materials were synthesized and incorporated into the monolith as the stationary phase. Then, the incorporated monolith was applied in the capillary electrochromatography system for separating small molecules.

Visual chiral recognition of aromatic amino acids with (S)-mandelic acid-based ionic liquids via complexation.

Recently, chiral ionic liquids have attracted increasing attention in analytical chemistry. However, only a few papers focus on the application of them in visual chiral recognition. Herein, two functionalized chiral ionic liquids derived from (S)-mandelic acid (1-butyl-3-methylimidazolium mandelate, CIL1 and N-butyl-N-methylpyrrolidinium mandelate, CIL2) were prepared for visual chiral recognition of aromatic amino acids for the first time. In the presence of Cu(II) and appropriate solvents, visual enantiomeric responses of phenylalanine, tryptophane, tyrosine and phenylglycine were observed. Relying on solubility or color differences, all chiral recognition could be finished within 5 min. The potential mechanism was investigated by means of infrared spectroscopy, ultraviolet spectroscopy, thermal gravity analysis, elemental analysis and scanning electron microscope. Results revealed that CuSO4 interacted with CIL1 and D-tryptophane in the ratio of 1:1.96:0.43 in relevant precipitate, and the different stability of complex was responsible for the chiral recognition. In addition, resolution of racemic tryptophane was performed, which offered excellent enantiomeric excess values (94.2% for CIL1 and 95.1% for CIL2 in solid phase). The proposed ionic liquids had strong enantioselectivity for aromatic amino acids and great potential in visual chiral recognition.

Effect of subcutaneous needling on visual analogue scale, IgG and IgM in patients with lumbar disc herniation: Study protocol clinical trial (SPIRIT Compliant).

BACKGROUND: Lumbar disc herniation (LDH) is a disease commonly seen in clinical practice. In the majority of such patients presenting in clinic, the symptoms can be relieved or even abolished after non-surgical treatment. Floating needle therapy has attracted considerable attention as a promising non-surgical technique to treat LDH, as demonstrated in previous studies. The purpose of the present study was to evaluate the outcomes of patients treated using this therapy in a single blind and randomized controlled trial by recording patient report questionnaires and objective test data, and to explore the feasibility and preliminary effects of floating needle therapy for patients with LDH. METHODS: A total of 80 patients who fulfilled the inclusion criteria were randomly divided into a Fu's subcutaneous needling (FSN) group and an acupuncture group then treated in accordance with procedures appropriate for a single blind and randomized controlled trial. The FSN group received 12 FSN therapy sessions over a 3-week period, and the acupuncture group received acupuncture therapy at specified points using acupuncture needles. The principal measurements were scored using the visual analogue scale (VAS), Japanese Orthopedic Association (JOA) Score, and Oswestry disability index (ODI) before and 3 weeks after treatment. Secondary measurements included immune function IgG and IgM measurements performed at the same time and adverse reactions during treatment. RESULTS: The results of this trial will be published on the website of China Clinical Trial Registration Center (http://www.chictr.org.cn/searchprojen.aspx) and in peer-reviewed journals or academic conferences. CONCLUSIONS: This study will explore the feasibility and preliminary effects of floating needle therapy for the treatment of patients with LDH. REGISTRATION: PROSPERO (registration number ChiCTR1900024045).

Gold nanoparticles-functionalized monolithic column for enantioseparation of eight basic chiral drugs by capillary electrochromatography.

Poly(glycidyl methacrylate)-co-(ethylene dimethacrylate) [poly(GMA-co-EDMA)] monoliths were prepared, and used as a support to attach gold nanoparticles (AuNP) via Au-S bond. Pepsin, acting as a chiral selector, was linked to the surface of the carboxyl-modified AuNP through a hydrochloride/N-hydroxysuccinimide coupling reaction. The material was characterized by scanning electron microscopy, energy dispersive X-ray spectrometry, transmission electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy and N2 adsorption-desorption isotherm. The pepsin@AuNP@poly(GMA-co-EDMA) monolith showed preferable enantioselectivity for hydroxychloroquine (HCQ), chloroquine (CHQ), hydroxyzine (HXY), labetalol (LAB), nefopam (NEF), clenbuterol (CLE), amlodipine (AML) and chlorpheniramine (CHL) in capillary electrochromatography (CEC). These racemic drugs were monitored at the maximum absorption wavelength (220 nm for HXQ, CHQ, HXY, LAB, NEF; 240 nm for AML; 215 nm for CLE, CHL). In comparison with the pepsin@poly(GMA-co-EDMA) monolith loaded with 5 nm AuNP, the pepsin@poly(GMA-co-EDMA) monolith loaded with 13 nm AuNP shows significantly enhanced enantiomeric resolution (HCQ: 0.62 → 3.45; CHQ: 0.60 → 2.11; HXY: 0.49 → 2.30; LAB: 1.03 → 2.45, 1.45 → 3.46, 0 → 0.67; NEF: 0.53 → 1.29; CLE: 0.42 → 0.56; AML: 0 → 0.83; CHL: 0.24 → 0.55). Pepsin concentration, buffer pH value, buffer concentration and applied voltage were investigated in detail with (±) HCQ and (±) HXY as model analytes. The reproducibility of intra-day, inter-day and column-to-column were explored, and found to be satisfactory. Graphical abstractSchematic presentation of the preparation of gold nanoparticles (AuNP) modified.

Maltodextrin-modified graphene oxide for improved enantiomeric separation of six basic chiral drugs by open-tubular capillary electrochromatography.

An electrochromatographic capillary was modified with graphene oxide (GO), and the coating was characterized by scanning electron microscopy, energy dispersive X-ray spectrometry, and Fourier transform infrared spectra. By utilizing maltodextrin (MD) as the chiral selector, the basic chiral drugs nefopam (NEF), amlodipine (AML), citalopram hydrobromide (CIT), econazole (ECO), ketoconazole (KET) and cetirizine hydrochloride (CET) can be enantiomerically separated on this CEC. Compared with an uncoated silica capillary, the resolutions are markedly improved (AML: 0.32 → 1.45; ECO: 0.55 → 1.89; KET: 0.88 → 4.77; CET: 0.81 → 2.46; NEF: 1.46 → 2.83; CIT: 1.77 → 4.38). Molecular modeling was applied to demonstrate the mechanism of enantioseparation, which showed a good agreement with the experimental results. Graphical abstractSchematic representation of the preparation of graphene oxide-modified capillary (GO@capillary) for enantioseparation of drug enantiomers. The monolayered GO was used as the coating of the GO@capillary. Then the capillary was applied to construct capillary electrochromatography system with maltodextrin for separation of basic chiral drugs.

Enantioseparation of amino alcohol drugs by nonaqueous capillary electrophoresis with a maltobionic acid-based ionic liquid as the chiral selector.

This study deals with the nonaqueous capillary electrophoretic enantioseparation of twenty-two amino alcohol drugs with a maltobionic acid (MA)-based ionic liquid (tetramethylammonium maltobionic acid, TMA-MA) as the novel chiral selector. In consideration of the poor solubility of MA in organic solvents, we managed to transform MA into ionic liquids (ILs) for the first time. Interestingly, this chiral selector exhibited powerful enantioselectivity towards the model analytes in company with boric acid. Systematical experiments were carried out to investigate the influence of concentration of TMA-MA, boric acid and tris (hydroxymethyl) aminomethane (Tris) as well as applied voltage on the enantioseparation. A great majority of enantiomers (except labetalol) were baseline separated under the optimized conditions and the effect of the molecular structure of amino alcohol drugs on the chiral separation was discussed. In addition, electrophoretic experiments, nuclear magnetic resonance (NMR), mass spectrometry (MS) and molecular modeling with the Gaussian program were employed to demonstrate the mechanism of chiral recognition. Based on the formation of an ionic liquid-boric acid-analyte complex, hydrogen binding was mainly responsible for enantioseparation.

Evaluation of an ionic liquid chiral selector based on clindamycin phosphate in capillary electrophoresis.

Recently, increasing attention has been given to the research on chiral ionic liquids (CILs) in chiral separation field; however, only a few literatures focus on the exploration of CILs as the sole chiral selector. In this study, an ionic liquid chiral selector based on antibiotic, namely tetramethylammonium clindamycin phosphate (TMA-CP), was originally synthesized and subsequently utilized for enantioseparation in capillary electrophoresis (CE). Remarkably improved separations of eight racemic analytes were achieved in TMA-CP system in contrast to the clindamycin phosphate (CP) system. The optimal separation conditions were determinated by systematic experiments on several crucial parameters including the type and proportion of organic modifier, CIL concentration, buffer pH, and applied voltage. Additionally, molecular modeling with AutoDock was applied to probe into the chiral recognition mechanism of the ionic liquid chiral selectors, which well corresponded with the experimental results. It is the first time that antibiotic-based ionic liquid was exploited as favorable sole chiral selector in CE, and this strategy has paved a new way for development of novel ionic liquids chiral selectors based on antibiotics. Graphical abstract.

[Effect of GnRHa controlled ovarian hyperstimulation on mouse embryo implantation and its mechanism].

The purpose of the present study was to investigate the effects and underlying mechanism of gonadotropin-releasing hormone agonist (GnRHa) controlled ovarian hyperstimulation (COH) on embryo implantation in mice. Forty female Kunming mice aged 9 weeks were randomly divided into two groups (control and COH groups). The COH group received intraperitoneal (i.p.) injections of aminocyclin acetate (GnRHa), human menopausal gonadotropin (HMG) and human chorionic gonadotropin (hCG), while the control group was given equal amount of physiological saline by i.p. injection. One male mouse and two female mice were put into the same cage at 16:00 on the hCG injection day, and on the fourth day of pregnancy, 10 mice from each group were killed. The levels of serum estradiol (E2) and progesterone (P) were measured by radioimmunoassay; HE staining was used to observe the morphology of ovarian and endometrial tissues. The protein expression levels of endometrial leukemia inhibitory factor (LIF), phosphorylated signal transducer and activator of transcription 3 (p-STAT3), heparin-binding epidermal growth factor-like growth factor (HB-EGF) and glycodelin A were detected by Western blot and immunohistochemistry. Ten mice from each group were sacrificed on the eighth day of pregnancy, and the status of the uterus and the average number of blastocysts were observed. The results showed that, compared with control group, the serum E2 level in COH group was significantly decreased (P < 0.05), while the P level was increased significantly (P < 0.05); the ovarian follicles at different developmental stages were rare, corpus lutea (CL) were visible and multiple, the endometrium was thinned, and the number of endometrial glands was reduced (P < 0.05); the contents of LIF, p-STAT3, HB-EGF and glycodelin A in the endometrium were decreased significantly (P < 0.05) on the fourth day of pregnancy; mouse blastocysts developed slowly and were decreased in number on the eighth day of pregnancy (P < 0.05). The above results suggest that GnRHa COH can affect embryo implantation in mice. The mechanism may be related to the imbalance of gonadal hormone, the changes in the structure of the endometrium and the expressions of LIF, p-STAT3, HB-EGF and glycodelin A in the implantation stage, which may lead to the decrease of endometrial receptivity and the abnormal dialogue between the embryo and the uterus.

[The effect of floating-needle therapy combined with rehabilitation training for the hand function recovery of post-stroke patients].

OBJECTIVE: To explore the improvement of hand motion function,spasm and self-care ability of daily life for stroke patients treated with floating-needle combined with rehabilitation training. METHODS: Eighty hand spasm patients of post-stroke within one year after stroke were randomly divided into an observation group and a control group, 40 cases in each one. In the two groups, rehabilitation was adopted for eight weeks,once a day,40 min one time. In the observation group, based on the above treatment and according to muscle fascia trigger point, 2~3 points in both the internal and external sides of forearm were treated with floating-needle. The positive or passive flexion and extension of wrist and knuckle till the relief of spasm hand was combined. The floating-needle therapy was given for eight weeks, on the first three days once a day and later once every other day. Modified Ashworth Scale(MAS), activity of daily life(ADL, Barthel index) scores and Fugl-Meyer(FMA) scores were used to assess the spasm hand degree,activity of daily life and hand motion function before and after 7-day, 14-day and 8-week treatment. RESULTS: After 7-day, 14-day and 8-week treatment, MAS scores were apparently lower than those before treatment in the two groups(all P<0. 05), and Barthel scores and FMA scores were obviously higher than those before-treatment(all P<0. 05). After 14-day and 8-week treatment, FMA scores in the observation group were markedly higher than those in the control group(both P<0. 05). CONCLUSION: Floating-needle therapy combined with rehabilitation training and simple rehabilitation training could both improve hand spasm degree, hand function and activity of daily life of post-stroke patients, but floating-needle therapy combined with rehabilitation training is superior to simple rehabilitation training for the improvement of hand function.