Human Albumin-Based Hydrogels for Their Potential Xeno-Free Microneedle Applications

Nowadays, hydrogels-based microneedles (MNs) have attracted a great interest owing to their outstanding qualities for biomedical applications. For the fabrication of hydrogels-based microneedles as tissue engineering scaffolds and drug delivery carriers, various biomaterials have been tested. They are required to feature tunable physiochemical properties, biodegradability, biocompatibility, nonimmunogenicity, high drug loading capacity, and sustained drug release. Among biomaterials, human proteins are the most ideal biomaterials for fabrication of hydrogels-based MNs; however, they are mechanically weak and poorly processible. To the best of the knowledge, there are no reports of xeno-free human protein-based MNs so far. Here, human albumin-based hydrogels and microneedles for tissue engineering and drug delivery by using relatively new processible human serum albumin methacryloyl (HSAMA) are engineered. The resultant HSAMA hydrogels display tunable mechanical properties, biodegradability, and good biocompatibility. Moreover, the xeno-free HSAMA microneedles display a sustained drug release profile and significant mechanical strength to penetrate the model skin. In vitro, they also show good biocompatibility and anticancer efficacy. Sustainable processible human albumin-based biomaterials may be employed as a xeno-free platform in vivo for tissue engineering and drug delivery in clinical trials in the future.     

高效液相色谱法同时快速检测腌腊肉制品中20种非法添加合成色素

采用亚3μm色谱柱建立了同时快速检测腌腊肉制品中20种非法添加合成色素的高效液相色谱法。样品经石油醚脱脂、乙醇-氨水-水(7∶2∶1)提取、钨酸钠溶液沉淀蛋白,采用Agilent Poroshell 120 EC C18(50 mm×4.6 mm,2.7μm)色谱柱以甲醇-0.02 mol/L乙酸铵(p H 5.5)为流动相梯度洗脱,二极管阵列检测器检测,外标法定量。结果表明,待测物可在17 min内实现完全分离。20种成分的质量浓度在0.15~20.0 mg/L范围内与峰面积呈线性关系,相关系数(r)大于0.998,方法的回收率为70.3%~107.9%,相对标准偏差(RSD)为0.5%~3.1%,检出限为0.1~0.2 mg/kg。与传统5μm色谱柱ACE C18(250 mm×4.6 mm,5μm)相比,本方法节约了62%的分析时间,并能在常规HPLC系统内使用,具有广阔的应用前景。     

氢化物发生–原子吸收光谱法测定铅粉中痕量砷、锑

建立氢化物发生–原子吸收光谱法联用测定铅粉中痕量砷、锑的方法。试样用稀硝酸溶解,用5%抗坏血酸溶液作为砷(Ⅴ)、锑(Ⅴ)的预还原剂,5%的硫脲溶液作为其它元素的掩蔽剂,选用1%硼氢化钠溶液作为还原剂,氢化物反应在10%盐酸介质中进行。在优化的试验条件下,砷、锑的质量浓度在0~20 ng/m L范围内与吸光度线性相关,相关系数r2分别为砷0.999 6,锑0.993 8,方法的检出限分别为砷0.40 ng/m L,锑0.75 ng/m L。砷、锑测定结果的相对标准偏差分别为4.96%,6.27%(n=6),铅粉样品加标回收率分别为砷87.6%,锑79.3%。该方法准确可靠,可用于测定铅粉中痕量砷、锑。     

新型低共熔溶剂的制备、表征及物性研究

以氯化1-丁基-3-甲基咪唑鎓([Bmim]Cl)和二元羧酸为原料,由不同摩尔比混合制备了一类新型低共熔溶剂,采用红外光谱对[Bmim]Cl和二元羧酸之间的作用进行了分析。分别测定了其粘度、电导率、密度、折射率等物理性质,并研究了温度、二元羧酸结构和摩尔比对这些物理性质的影响。结果表明,新型低共熔溶剂的粘度随温度的升高而降低,电导率随温度的升高而增加。温度对两者的影响可以采用VTF方程进行精确地拟合。新型低共熔溶剂的密度随温度的升高而呈线性下降。对新型低共熔溶剂的过量摩尔体积进行计算的结果表明,过量摩尔体积均为正值,二元羧酸对过量摩尔体积的贡献远大于[BMIM]Cl,而结构特性的贡献多于物理作用。折射率和密度随二元羧酸碳数的变化趋势基本相似。     

A Preloaded Amorphous Calcium Carbonate/Doxorubicin@Silica Nanoreactor for pH‐Responsive Delivery of an Anticancer Drug

Biomedical applications of nontoxic amorphous calcium carbonate (ACC) nanoparticles have mainly been restricted because of their aqueous instability. To improve their stability in physiological environments while retaining their pH‐responsiveness, a novel nanoreactor of ACC–doxorubicin (DOX)@silica was developed for drug delivery for use in cancer therapy. As a result of its rationally engineered structure, this nanoreactor maintains a low drug leakage in physiological and lysosomal/endosomal environments, and responds specifically to pH 6.5 to release the drug. This unique ACC–DOX@silica nanoreactor releases DOX precisely in the weakly acidic microenvironment of cancer cells and results in efficient cell death, thus showing its great potential as a desirable chemotherapeutic nanosystem for cancer therapy.     

Synthesis and magnetic properties of organic multilayer films based on the layer‐by‐layer assembly

Two polymers containing pyridine rings were prepared by free‐radical polymerization and confirmed by Fourier transform infrared and ¹H NMR spectra. The preparation of four multilayer films that were obtained by self‐assembly of the polymer and the transition metal neutralized polyelectrolyte on PE substrate was described. UV–vis spectra and atomic force microscopy images were applied to characterize these films and indicate the uniform assembling process. The driving force for building up the multilayer films was identified by infrared spectroscopy to be the coordination interaction. The magnetic behavior was examined as a function of magnetic field strength at 30 kOe and as a function of temperature (5–300 K). All films display strong soft ferromagnetic properties and higher than those of the bulk materials. The magnetic results show that the layer‐by‐layer self‐assembling approach is beneficial to the ordered alignment of adjacent paramagnetic spins and induces better magnetic phenomena. Copyright © 2015 John Wiley & Sons, Ltd.     

Redox‐Neutral α‐Allylation of Amines by Combining Palladium Catalysis and Visible‐Light Photoredox Catalysis

An unprecedented α‐allylation of amines was achieved by combining palladium catalysis and visible‐light photoredox catalysis. In this dual catalysis process, the catalytic generation of allyl radical from the corresponding π‐allylpalladium intermediate was achieved without additional metal reducing reagents (redox‐neutral). Various allylation products of amines were obtained in high yields through radical cross‐coupling under mild reaction conditions. Moreover, the transformation was applied to the formal synthesis of 8‐oxoprotoberberine derivatives which show potential anticancer properties.     

Synergetic Spin Crossover and Fluorescence in One‐Dimensional Hybrid Complexes

Hybrid materials integrated with a variety of physical properties, such as spin crossover (SCO) and fluorescence, may show synergetic effects that find applications in many fields. Herein we demonstrate a promising post‐synthetic approach to achieve such materials by grafting fluorophores (1‐pyrenecarboxaldehyde and Rhodamine B) on one‐dimensional SCO Fe^II structures. The resulting hybrid materials display expected one‐step SCO behavior and fluorescent properties, in particular showing a coupling between the transition temperature of SCO and the temperature where the fluorescent intensity reverses. Consequently, synergetic effect between SCO and fluorescence is incorporated into materials despite different fluorophores. This study provides an effective strategy for the design and development of novel magnetic and optical materials.