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OBJECTIVE: To establish a high-performance liquid gel chromatography (HPLC-ELSD) method for the detection of macromolecular substances in Compound Kushen injection. METHODS: TSKgel G2000SWXL (7.8 mm×300 mm, 5 μm) chromatographic column was used. A 20 mmol•L-1 ammonium acetate aqueous solution was used as the mobile phase. The column temperature was maintained at 25℃, the flow rate was 0.8 mL•min-1, and the parameters of the evaporative light detector (drift tube temperature 55℃, atomization temperature 55℃, nitrogen flow rate, 1.8 L•min-1), a method for detecting macromolecular substances was established, and eleven batches of Compound Kushen injection were tested for macromolecular substances. RESULTS: No macromolecular substances was detected in the eleven batches of Compound Kushen injection, indicating that after the step-by-step removal of impurities, macromolecular substances have been removed from the finished Compound Kushen injection products. CONCLUSION: This method is simple and fast, which can be used for the detection of macromolecular substances in Compound Kushen injection, it provides a basis for improving the quality standards of Compound Kushen injection.
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Objective To explore the effect of macromolecule on the mass transfer process of berberine during membrane separation. Methods The membrane filtration experiment combined with molecular dynamics simulation were used to analyse and predict the interaction between micromolecule effective substance and the macromolecule commonly existed in the water extract of Chinese material medica. Firstly, the mixed simulation solution of berberine and macromolecule was prepared to carry out the membrane separation experiment. The transmittance and adsorption rate of berberine, the rejection and adsorption rate of macromolecule was determined to analyse the effect of macromolecule on the transmittance of berberine in the membrane filtration process. Then, the molecular dynamics simulation software was used to establish simulation system to calculate the interaction between berberine and macromolecule, so as to analyse the effect of macromolecule on the mass transfer process of berberine. Results The permeability of berberine was significantly reduced after being mixed with the macromolecule. The total interaction energy between protein, starch, pectin and berberine was calculated as -122.723 3, -83.613 0, and -125.815 9 kJ/mol, respectively. The interaction energy between starch and berberine was minimum, and the interaction energy between protein and berberine was similar as that between pectin and berberine. Conclusion In membrane separation process, the interaction between the macromolecule and berberine is the main factor affecting the mass transfer process of berberine, and the strength of the interaction results in the difference in the permeability of berberine.
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Enrichment and immobilization of analytes by chemical bonding or physical adsorption is typically the first step in many commonly used analytical techniques. In this paper, we discuss a permeation drag based technique as an alternative approach for carrying out location-specific immobilization of macro-molecular analytes. Fluorescein isothiocyanate (FITC) labeled macromolecules and their complexes were enriched near the surface of ultrafiltration membranes and detected by direct visual observation and fluorescence imaging. The level of macromolecule enrichment at the immobilization sites could be controlled by manipulating the filtration rate and thereby the magnitude of permeation drag. Higher enrichment as indicated by higher fluorescence intensity was observed at higher filtration rates. Also, larger macromolecules were more easily enriched. The feasibility of using this technique for detecting immunocomplexes was demonstrated by carrying out experiments with FITC labeled bovine serum al-bumin (FITC-BSA) and its corresponding antibody. This permeation drag based enrichment technique could potentially be developed further to suit a range of analytical applications involving more sophis-ticated detection methods.
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Recently, more and more attentions of drug development are placed to macromolecules, such as monoclonal antibodies, proteins, etc. It has become one of the most promising areas in drug research and development in 21st Century. In terms of the structure and the ADMET (absorption, distribution, metabolism, excretion and toxicity), macromolecules is different from small molecule drugs, which lead to a distinct modeling strategy. The characterization of biologics ADMET processes and its application in the PK model selection of macromolecules are reviewed in this paper.
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A size exclusion chromatography method ( SEC) was established for the screening of macromolecules in traditional Chinese medicine (TCM) injections. In the experiment, TCM was collected through 0. 45μm hybrid filter and separated by SEC with MAbPac SEC-1 column. Acetonitrile was added by post-column mode with a flow rate of 0. 2 mL/min to enhance the detection sensitivity, and 25 mmol/L ammonium formate was used as the mobile phase at flow rate of 0. 2 mL/min. The charged aerosol detection was carried out with Dextran and Tween as the reference standards. The molecular weight distribution of Dextran ranged from 2500 to 133800 had a good linear relationship with the retention time. No macromolecules were detected out in the selected traditional Chinese medicine injections except Kuhuang injections.
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After Human Gene Project, studying the kinetics of DNA translocation through a nanopore, and developing a novel fast DNA sequencing technology by using nanopore have become one of the hot in gene-research). This contribution provides an overview of nanopore macromolecular identification,including bionanopore and solid-state nanopore, while the perspective of these research are also summarized.
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PURPOSE: To evaluate the NMR relaxation properties and imaging characteristics of tissue-specificity for a newly developed macromolecular MR agent. MATERIALS AND METHODS: Phthalocyanine (PC) was chelated with paramagnetic ion, Mn. 2.01g(5.2 mmol) of Phthalocyanine was mixed with 0.37g (1.4 mmol) of Mn chloride at 310 degrees C for 36 hours and then purified by chromatography (CHC13/CH3OH 98/2 v/v, Rf, 0.76) to obtain 1.04g (46%) of MnPC (molecular weight = 2000d), The T1/T2 relaxivity of MnPC was measured in 1.5T(64 MHz) MR using 0.1 mM MnPC. The MR image characteristics of MnPC was evaluated using spin-echo (TR/TE = 500/14 msec) and gradient-echo (FLASH) (TR/TE = 80/4 msec, flip angle = 60) techniques in 1.5T MR scanner. The images of rabbit liver were obtained every 10 minutes up to 4 hours. To study the effect of concentration on image, 20 mM, 50 mM, 100 mM of MnPC were tested. RESULTS: The relaxivities of MnPC at 1.5T (64MHz) were R1 = 7.28 mM-1S-1, R2 = 55.56 mM-1S-1. Compared to the values of Gd-DTPA (R1[= 4.8 mM-1S-1), R2[= 5.2 mM-1S-1]), both T1/T2 relaxivities of MnPC were higher than those of Gd-DTPA. For both of SE and FLASH techniques, the contrast enhancement reached maximum at 10 minutes after bolus injection and the enhancement continued for more than 2 hours. When compared with small molecular weight liver agents such as Gd-EOB-DTPA, Gd-BOPTA and MnDPDP, MnPC was characterized by more prolonged enhancement time. The time course of MR images also revealed biliary excretion of MnPC. CONCLUSION: We developed a new macromolecular MR agent, MnPC. The relaxivities of MnPC were higher than those of small molecular weight Gd-chelate. Hepatic uptake and biliary excretion of MnPC suggests that this agent is a new liver-specific MR agent.
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Chromatography , Gadolinium DTPA , Liver , Molecular Weight , RelaxationABSTRACT
Objective To evaluate the clinical efficacy of China-made expanded polytetrafluoroethylene (ePTFE) in the treatment of facial defects and hollow deformities on the face. Methods Facial augmentation was performed in different sites as the forehead, temple, nose, chin, nosal base and maxilla, respectively, to correct the facial defects and hollow deformities, by using either China-made ePTFE (Experimental Group) or imported ePTFE (Control Group). Postoperative parameters between the two groups were compared. Results The Experimental Group included 16 patients (18 sites), in whom the postoperative follow-up was conducted for 6~9 months. In this group, a secondary infection (in the nose) occurred in 1 patient because the implant was placed too superficially and too close proximity to the incision, and the implant was removed out. Delayed healing of the incision (in the chin) with uncovered implant was found in 1 patient, who was cured by the change of dressing. In the rest of the patients, no obvious allergic, inflammatory or rejection reaction was seen and a good cosmetic result was achieved. The satisfactory rate of this group was 94.4%(17/18). The Control Group included 10 patients (20 sites). The implant was found bared and then removed in 1 patient (in the nose). The satisfactory rate of this group was 91.7%(11/12). There were no statistical differences between the two groups in the wound healing ( ? 2 =1 109, P =0 574), the adverse reaction ( P =1 000), and the clinical efficacy ( P =1 000). Conclusions China-made ePTFE gives histocompatibility as good as imported one. It is suitable for filling the soft tissue and can be used as a safe and economical alternative.