Calcium‐Modified Silk as a Biocompatible and Strong Adhesive for Epidermal Electronics

With the increasing interest and demand for epidermal electronics, a strong interface between a sensor and a biological surface is essential, yet achieving such interface is still a challenge. Here, a calcium (Ca)‐modified biocompatible silk fibroin as a strong adhesive for epidermal electronics is proposed and the physical principles behind its interfacial and adhesive properties are reported. A strong adhesive characteristic (>800 N m^?1) is observed because of the increase in both viscoelastic property and mechanical interlocking through the incorporation of Ca ions. Furthermore, additional key characteristics of the Ca‐modified silk: reusability, stretchability, biocompatibility, and conductivity, are reported. These characteristics enable a wide range of applications as demonstrated in four epidermal electronic systems: capacitive touch sensor, resistive strain sensor, hydrogel‐based drug delivery, and electrocardiogram monitoring sensor. As a reusable, biocompatible, conductive, and strong adhesive with water‐degradability, the Ca‐modified silk adhesive is a promising candidate for the next‐generation adhesive for epidermal biomedical sensors.     

柠檬精油抑制酪氨酸酶活性的研究

本文通过测定抑制酪氨酸酶活性,DPPH (1, 6-双(二苯基膦)己烷)清除自由基能力以及铜离子螯合能力,研究了柠檬精油和其组成中的六种挥发性成分抑制酪氨酸酶的机理。结果表明：柠檬精油和挥发性成分对酪氨酸酶均产生良好的抑制作用,通过空间位阻效应和清除氧自由基等非抑制酪氨酸酶活性部位的机理;其中柠檬醛（含量为2.16%）和乙位蒎烯（含量为14.30%）对酪氨酸酶的抑制率分别为76.64%和61.82%,表现出显著的抑制能力;然而,D-柠檬烯（含量为61.41%）的抑制率仅有33.25%;六种挥发成分的协同效应使得这些物质的混合物对酪氨酸酶的抑制作用强于柠檬精油;随着浓度的增加,柠檬精油抑制能力增加,其中达到50%的抑制能力的浓度为620±15.72 μg/mL;Linewear-Burk曲线说明柠檬精油的抑制类型为非竞争性,并且Km=0.30±0.003mM;基于DPPH实验得知柠檬精油和柠檬醛具有较强的清除自由基能力,两者的50%清除率浓度分别为123.65±20.20 mg/mL和176.54±23.20 mg/mL;铜离子螯合实验证明六种组分虽然表现为良好的抑制酪氨酸酶作用但均不与酪氨酸酶活性部位相结合。以上结果表明柠檬精油在食品和化妆品行业中可作为潜在的生物性和功能性天然原料。     

鳗鱼钙螯合肽制备工艺研究

本文以鳗鱼尾为原料,采用现代酶解技术高效制备鳗鱼钙螯合肽。系统研究了单酶的种类、多酶复配、酶解时间和酶添加量对蛋白回收率、肽得率以及产物钙螯合能力的影响规律,并获得最佳酶解工艺:添加鳗鱼尾蛋白3.5‰的胰酶,调整pH至8.0在55℃下酶解3 h,然后调整体系pH至4.0,加入鳗鱼尾蛋白3.5‰的酸性蛋白酶在55℃下继续酶解2 h得到鳗鱼肽,蛋白回收率和肽得率分别为66.61%和52.46%。并在此基础上,研究了螯合温度、pH值以及质量比对鳗鱼肽螯合能力的影响,优化获得螯合条件为:鳗鱼肽在30℃,pH值为9.0条件下按肽钙质量比1:2,与钙离子螯合30 min得到鳗鱼钙螯合肽,螯合物的钙离子含量为56.78 mg/g。通过氨基酸成分分析,发现鳗鱼肽与钙的螯合反应中,谷氨酸和天冬氨酸等酸性氨基酸的贡献最大。     

具有铁螯合能力的驴骨胶原肽酶解条件优化及微观形态

为充分开发利用驴骨资源,开发一种酶解驴骨蛋白从而得到驴骨胶原蛋白肽的方法,考察该酶解肽与亚铁离子的螯合能力,并将其产物进行表征。以亚铁离子螯合率为考察指标,筛选最优酶种类,通过单因素实验和考虑交互作用的正交实验优化确定驴骨的最佳酶解条件。结果表明,驴骨的最佳预处理条件为121 ℃蒸煮30 min,木瓜蛋白酶为最佳酶,优化过后的酶水解工艺参数为温度50 ℃、pH 7.0、酶底比1 000 U/mL、时间3 h,此时驴骨胶原肽和亚铁离子的螯合率为38.40%,可得到微观结构为片状的螯合产物。木瓜蛋白酶酶解驴骨蛋白可以制备有螯合亚铁离子能力的驴骨胶原肽,具有促铁吸收的潜力,对开发驴骨胶原肽相关产品具有科学参考作用。     

蚕蛹多肽螯合钙的制备工艺优化及结构表征

利用蚕蛹多肽为原料制备多肽螯合钙,以可溶性钙含量为主要指标,综合考察螯合率和得率,研究了螯合pH、温度、时间以及肽钙比等单因素的影响,并进一步通过响应面优化法对制备工艺进行优化,确定最优的反应条件为反应时间80min、反应温度73℃、pH 10、肽钙质量比3.41.0,该条件下蚕蛹多肽螯合钙的含钙量为14.51%。傅利叶红外光谱分析表明蚕蛹多肽主要通过羧基、胺基和磷酸基团与钙离子结合。     

交联聚乙烯胺的合成及性能研究

以交联聚丙烯酰胺为母体 ,利用Hofmann降解的方法合成交联聚乙烯胺 ,研究了不同实验条件对交联聚乙烯胺降解率的影响 ;并用交联聚乙烯胺络合金属离子 ,测定不同实验条件对络合作用的影响 ,发现交联聚乙烯胺金吸附量达到 4 883mol/ g。采用红外光谱、热重分析等方法初步探讨了交联聚乙烯胺络合物的性质     

The Oral Ferroportin Inhibitor VIT-2763 Improves Erythropoiesis without Interfering with Iron Chelation Therapy in a Mouse Model of β-Thalassemia

In β-thalassemia, ineffective erythropoiesis leads to anemia and systemic iron overload. The management of iron overload by chelation therapy is a standard of care. However, iron chelation does not improve the ineffective erythropoiesis. We recently showed that the oral ferroportin inhibitor VIT-2763 ameliorates anemia and erythropoiesis in the Hbb^th3/+ mouse model of β-thalassemia. In this study, we investigated whether concurrent use of the iron chelator deferasirox (DFX) and the ferroportin inhibitor VIT-2763 causes any pharmacodynamic interactions in the Hbb^th3/+ mouse model of β-thalassemia. Mice were treated with VIT-2763 or DFX alone or with the combination of both drugs once daily for three weeks. VIT-2763 alone or in combination with DFX improved anemia and erythropoiesis. VIT-2763 alone decreased serum iron and transferrin saturation (TSAT) but was not able to reduce the liver iron concentration. While DFX alone had no effect on TSAT and erythropoiesis, it significantly reduced the liver iron concentration alone and in the presence of VIT-2763. Our results clearly show that VIT-2763 does not interfere with the iron chelation efficacy of DFX. Furthermore, VIT-2763 retains its beneficial effects on improving ineffective erythropoiesis when combined with DFX in the Hbb^th3/+ mouse model. In conclusion, co-administration of the oral ferroportin inhibitor VIT-2763 and the iron chelator DFX is feasible and might offer an opportunity to improve both ineffective erythropoiesis and iron overload in β-thalassemia.     

硝基腐植酸提取及螯合铁制备实验研究

采用碱溶-酸析法提取硝基腐植酸,考察各因素对腐植酸提取率的影响,并利用所得的硝基腐植酸制备鳌合铁。实验结果表明:提取硝基腐植酸的最佳工艺条件是煤样与硝酸溶液质量比2.86,硝酸溶液w(HNO_3)35%,硝化时间40 min,硝化温度70℃,氢氧化钠溶液w(NaOH)2.5%,每克褐煤氢氧化钠溶液用量8 mL,碱提时间30 min,碱提温度70℃,最大提取率为98.65%,经螯合反应后,有效铁收率大于75%,效果良好。     

聚环氧琥珀酸与Ca~(2+)的螯合反应研究

为考察聚环氧琥珀酸对Ca~(2+)的螯合能力及其影响效果,采用滴定法考察了聚环氧琥珀酸与Ca~(2+)在不同反应条件下发生螯合反应的钙螯合值。单因素试验结果表明,聚环氧琥珀酸的钙螯合值受反应温度的影响较为明显,在5~45℃范围内随温度升高而增大,在45~65℃范围内随温度上升而减小。但在溶液初始pH值为6.5~9.5的条件下,钙螯合值受溶液初始pH值的影响较小。通过正交试验获得的最大钙螯合值为124.5 mg/g,对应的螯合官能团最大利用率仅为54.4%,而剩余的螯合官能团可能为PESA的致晶格畸变作用和分散作用提供了物质基础。