固相萃取-超高效液相色谱/串联质谱法检测人体血清中邻苯二甲酸二(2-乙基已基)酯代谢物

建立了固相萃取-超高效液相色谱/串联质谱法检测人体血清中邻苯二甲酸二(2-乙基已基)酯(DEHP)代谢物.血清样品中加入乙酸钠溶液及内标13C4邻苯二甲酸单乙基已基酯(13C4MEHP)后,在37℃条件下用β-葡萄糖醛苷酶酶解提取12h,提取液经MAX固相萃取小柱净化并浓缩到纯水中.以甲醇5 mmol/L乙酸铵溶液为流动相,经Waters UPLC(R)HSS T3色谱柱分离后,在电喷雾离子源负离子模式下,以多反应监测(MRM)方式进行扫描,内标法定量.DEHP代谢物在1.0～100.0 μg/L范围内线性关系良好,检出限均为0.1 μg/kg,回收率89.6％～103.2％.该方法灵敏度高,准确度好,可作为监测人群内暴露的重要技术支撑.     

Applications of covalent organic frameworks (COFs):From gas storage and separation to drug delivery

Covalent organic frameworks (COFs) are an emerging class of porous covalent organic structures whose backbones were composed of light elements (B, C, N, O, Si) and linked by robust covalent bonds to endow such material with desirable properties, i.e., inherent porosity, well-defined pore aperture, ordered channel structure, large surface area, high stability, and multi-dimension. As expected, the above-mentioned properties of COFs broaden the applications of this class of materials in various fields such as gas storage and separation, catalysis, optoelectronics, sensing, small molecules adsorption, and drug delivery. In this review, we outlined the synthesis of COFs and highlighted their applications ranging from the initial gas storage and separation to drug delivery.     

Effect of a nano-sized natural clinoptilolite modified by the hexadecyltrimethyl ammonium surfactant on cephalexin drug delivery

The use of porous materials as host systems for medical applications has been considered in recent years. The aim of this work is to construct an efficient adsorbent for the adsorption and delivering of cephalexin. For this pupose, pretreated natural nano-sized clinoptilolite (NZ) was modified by the cationic hexadecyltrimethyl ammonium surfactant (HDTMA), and the obtained modified zeolite nanoparticles (SMZ) were used to design systems for storage and release of cephalexin (CPX). The adsorbed and released extents of the drug onto/from the modified zeolite were determined by UV–Vis spectroscopy. The results showed that both decreasing the particle size of clinoptilolite and modifying its surface significantly increase the adsorbed drug extent. All the compounds were characterized by SEM, TEM, FT–IR, TG/DTG, and XRD. TG/DTG and also FT–IR results showed sufficient loading amounts of HDTMA and CPX onto the raw and modified zeolite, respectively. It was proven by means of TG that the composites are more stable thermally when the admicelles contain cephalexin in their interior. IR spectroscopy studies indicated that the zeolite structure remained unchanged after the modification with the surfactant and after the cephalexin drug has been loaded. Due to the presence of hydroxyl and amine groups in the cephalexin structure, pH plays an important role on the adsorbed CPX extent, so that the maximum adsorbed CPX was observed at pH = 12. While the delivery of CPX was better at pH = 2, because at alkaline pHs, the anionic carboxylate form of CPX has higher attractive force with the positive head of the surfactant on the SMZ. Hence, the stomach's acidic pH is appropriate for drug delivery. The effects of some cations in the delivery extent confirm that the diet can significantly affect the delivery of the CPX from the proposed adsorbent.     

Applications of Pattern Recognition in Drug Discovery

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｅｑｕｅｎｃｉｎｇｏｆｔｈｅｈｕｍａｎ ｇｅｎｏｍｅｉｓｅｓｓｅｎ ｔｉａｌｌｙｃｏｍｐｌｅｔｅ .Ｔｈｅｒｅａｐｐｅａｒｓｔｏｂｅａｌｉｔｔｌｅｏｖｅｒ4 0 0 0 0 ｇｅｎｅｓ .Ｓｃｉｅｎｔｉｆｉｃｅｘｃｉｔｅｍｅｎｔｈａｓｍｏｖｅｄｏｎｔｏｔｈｅｐｒｏｔｅｏｍｅ ,ｔｈｅｆｅｗｈｕｎｄｒｅｄｔｈｏｕｓａｎｄｐｒｏｔｅｉｎｓｆｏｒｗｈｉｃｈｔｈｅ ｇｅｎｅｓｐｒｏｖｉｄｅｔｈｅｃｏｄｅ .Ｔｈｅｓｅ ｐｒｏｔｅｉｎｓｔｒｕｃｔｕｒｅｓａｒｅｌｉｋｅｌｙｔｏｅｍｅｒｇｅｗｉｔｈ…     

The characters of self-assembly core/shell nanoparticles of amphiphilic hyperbranched polyethers as drug carriers

The characters of self-assembly core/shell nanoparticles of amphiphilic hyperbranched polyethers (HP-g-PEO) as drug carriers were investigated. The HP-g-PEO consisting of hydrophobic HP-g-PEO core and hydrophilic poly(ethylene glycol) arms was prepared by the cation ring-opening polymerization. A series of HP-g-PEO samples with different degree of branching (DB) were synthesized under various reaction temperatures. Nanoparticles (NP) were obtained by self-assembly of HP-g-PEO in aqueous media. The structure of resulting HP-g-PEO was characterized by IR, ¹³CNMR and GPC. Dynamic light scattering and transmission electron microscopy were applied to characterize the sizes and size distributions of NP. The results demonstrated that the mean diameters of NP were less than 100 nm, which exhibited uniform spherical formations and narrow size distributions. Using hydrophobic drug Probucol (PRO) as model drug, the particle sizes of drug loaded NP were larger than relative blank NP. The drug loading efficiency (LE) and incorporation efficiency (IE) of these NP were achieved to 35 and 89%, respectively. The in vitro release of PRO from the NP exhibited a sustained release and the cumulative drugs released for more than 600 h. The most important factor to affect drug release was the value of DB of HP-g-PEO. With the DB of HP-g-PEO increasing, the size and size distribution of NP decreased as well as the release rate. However, the small DB was beneficial to the LE of NP. Nanoparticle size and size distribution, LE, IE, and drug release rate were slightly affected by the initial solution concentration of polyethers. The co-incorporated hydrophilic drug had influence slightly on the release of drug from drug loaded NP. The results of in vitro drug release suggested that the core/shell NP performed good controlled release behaviors with potential practice as novelty drug delivery vehicles.     

Molecular structure of N-(2-phenylethyl)amide of α-(1,1-ethylenedioxy)-ethyl γ-hydroxybutyric acid (I) and1H NMR spectra of (I) and N-(p-methoxybenzyl)derivative (III)

The spectroscopic and X-ray investigation of the N-(2-phenylethyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are reported. The¹H NMR spectra for the title structure and for the N-(p-methoxybenzyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are given. The N-(2-phenylethyl)amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid, C₁₆H₂₃O₄N, crustallizes in the monoclinic space groupP2 ₁/c witha=21.547(5),b=6.333(2),c=11.822(3) Å and =101.01(2)°. The dioxolane ring has a half-chair conformation with C₂(O3)=2.4° and ||_av=18.2°. The inconsiderable deviations from planarity of the six atoms of the amide group are caused mainly by twist around the C4–N1 bond and out-of-plane bending at the N1 atom ((C4–N1)=4°, X_N =7°, X_c =0.4° ). The amide group plane is nearly coplanar with the phenyl ring. The molecules are connected by two intermolecular hydrogen bonds.     

Effect of the area of a lithium niobate transducer on the efficiency of ultrasonic atomization driven by resonance vibration

In recent years, individual control of one’s personal environment has been drawing increasing attention due to the growing interest in health care. Wearable devices are especially useful because of their controllability regardless of location. Humidity is one of the inevitable factors in the personal environment as a preventive against infectious diseases. Although atomization devices are commonly used as a method of humidity control, at present, there are no wearable humidity control devices. Vibration of a lithium niobate (LN) device in the thickness mode is a promising piezoelectric method for miniaturization of atomization devices for humidity control. To miniaturize the atomization device, the transducer size needs to be small not so much as to decrease the atomization efficiency. However, the effect of the device area on the atomization efficiency of LN at a size suitable for mounting in wearable devices has not been studied. Here, we conducted an atomization demonstration of LN devices with different sizes to evaluate particle size and atomization efficiency. Furthermore, to reveal the relationship between vibration behavior and atomization efficiency, resonance vibration in the MHz frequency band was evaluated by the finite element method and an impedance analyzer. The results showed that the peak size of water particles atomized by each device was in the range of 3.2 to 4.2 µm, which is smaller than particles produced by typical piezoelectric ceramics. Moreover, the best LN size for efficient atomization was found to be 8 mm × 10 mm among the five LN device sizes used in experiments. From the relationship between vibration behavior and atomization efficiency, the size of the transducer was suggested to affect the vibration mode. The obtained result suggested that the LN device is suitable for small wearable nebulizer devices.     

Chemical Modification of EVA for DrugRelease Application

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聚(醚-酐)凝胶性能的优化及用于包载难溶性药物的研究

在制备聚醚酐凝胶的基础上, 用两种不同的可光交联疏水性单体与聚醚酐大分子单体在紫外光引发下制备三维交联凝胶, 使得凝胶的溶胀性能和亲-疏水性能发生变化, 从而影响凝胶与难溶性药物的相容性; 选用吲哚美辛为模型药物, 通过后包合法将其包载于凝胶网络中, X射线衍射(XRD)检测结果表明, 药物能以分子或无定形态分散于其中, 优化后的凝胶可得到更高的载药量和包封率, 能有效地提高疏水性药物的溶出度, 且药物体外释放速率与单纯聚醚酐凝胶相比, 被有效延缓, 更适于临床应用.