药物偶联亲和高分子微球对牛血蛋白吸附性能研究

在制备亲和高分子乳液微球基础上,对其进行空间臂改性和药物分子偶联制得PSGN-MTA亲和高分子微球药物。为研究亲和高分子微球生物相容性,考察了高分子微球药物在缓冲液中药物释放行为及对BSA蛋白吸附能力。结果表明,亲和微球表面化学键合MTA药物浓度较高且分布均匀时,对BSA蛋白的吸附过程较符合一级动力学方程。还考察了pH值对BSA蛋白吸附的影响,中性条件时PSGN-MTA微球对于BSA吸附效果较好。     

磁性微球与蛋白质相互作用的微量热研究

以牛血清白蛋白(BSA)为生物模型,采用微量热法自动跟踪磁性微球与BSA相互作用的全过程,研究了磁性微球与BSA相互作用的微量热;采用分光光度法测定了磁性微球所吸附的蛋白质容量;建立了磁性微球表面性质与蛋白质吸附容量的关系.结果表明,微量热法与传统的光度法所得结果大致相当,即相互作用的热越多,吸附蛋白质的容量越大,而且偶联羧基的磁性微球比无官能团的微球具有更大的吸附热和吸附容量.     

氨基表面修饰的高分子乳液微球对牛血白质BSA吸附性能的研究

以苯乙烯St和甲基丙烯酸环氧丙酯GMA为单体,两性偶氮类化合物V50为引发剂,运用功能单体多段加料的无皂乳液聚合法制备亲和高分子乳液基球PSG,并选择双氨基封端的聚乙二醇作为空间臂分子,进行表面修饰反应,考察了高分子乳液微球对牛血蛋白BSA的吸附性能,并着重研究了吸附时间和温度、BSA初始浓度、离子强度等因素对吸附反应的影响。实验结果表明,空间臂表面修饰的高分子微球作为载体材料,固定药物分子等生物活性物质,可通过控制吸附条件,如pH,温度,反应时间等,减少蛋白质分子的非特异性吸附,且保持生化分子的较高活性。     

复合磁性壳聚糖微球对BSA的吸附机理研究

将脱乙酰度为85%的壳聚糖包裹在由二价和三价的铁离子共沉淀制得的Fe3O4磁子表面,用环氧氯丙烷作为交联剂进行交联制成磁性壳聚糖(简称MC),用于吸附蛋白质一磷酸氢二钠一柠檬酸缓冲溶液中的小牛白蛋白(BSA),利用TEM(透射电镜)、IR(红外光谱)、TG-DSC(失重-差热)、XRD(粉末衍射)分析微球的形貌、组成及热件能,考察了牛白蛋白的初始浓度、溶液pH及保温时间对蛋白质吸附程度的影响.结果显示,pH增大使蛋白质的吸附量减小;在一定范围内,增大蛋白质的初始浓度和延长保温时间均有利于增加蛋白质的吸附量,温度对微球吸附蛋白质的影响比较复杂.     

表面带磺酸基团的聚苯乙烯微球的制备及其对蛋白质的吸附

研究了运用分散聚合法,在乙醇/水混合介质中,制备2-丙烯酰胺基-2-甲基丙磺酸(AMPS)与苯乙烯(St)的共聚微球。运用红外、核磁共振、激光光散射和扫描电子显微镜对功能微球进行表征。阐述了该微球对牛血清蛋白(BSA)的吸附量与吸附时间和pH值的关系。结果表明:功能微球对BSA的吸附先随时间的增长而增大,一段时间后达到平衡吸附。当pH值接近BSA等电点(pI=4.7)时,BSA的吸附量达到最大值。     

基于阳离子β-环糊精的胆红素吸附剂的制备与性能研究

多孔二氧化硅微球(SP-300)作为载体使用3-(2,3-环氧丙氧)丙基三甲氧基硅烷(KH-560)作为活化剂,以二甲基氨基吡啶(DMAP)作为催化剂在其表面引入环氧基团。β-环糊精(β-CD)经N-2,3-环氧丙基三甲基氯化铵(EPTAC)进行阳离子修饰后作为配基,在碱性条件固载于多孔二氧化硅微球表面制备成多孔二氧化硅微球固载阳离子β-环糊精(SP-EPTAC-β-CD)吸附剂。考察活化多孔二氧化硅微球的影响因素、吸附剂的吸附性能和血液相容性。结果显示活化多孔二氧化硅微球的环氧密度受活化剂用量、反应温度和反应时间的影响,合成的吸附剂对胆红素的吸附量可达0.99μmol/ml,吸附率为44.9%,并表现出一定的选择性,对血浆其他有用成分吸附较少。此外,吸附剂对血细胞粘附较少且溶血率5%,表现出良好的血液相容性。     

用光谱探针体研究非光谱物质与生物大分子结合作用：十二烷基苯磺酸钠/灿烂甲酚蓝/蛋白质反应体系

选择灿烂甲酚蓝(BCB)作为光谱探针体，应用微表面吸附-光谱修正(MSASC)技术，研究了十二烷基苯磺酸钠(SDBS)与3种蛋白质(BSA：牛血清蛋白，OVA：卵清蛋白，Mb：肌红蛋白)的结合反应. 在pH=2.81的酸性介质中，BCB-SDBS和SDBS-蛋白质反应符合Langmuir等温吸附. 通过折点法验证产物的表征数据. 实验表明研究体系中生成了结合物，并考察了温度、盐度对结合溶液的影响，测定了产物结合常数等.     

胰蛋白酶分子表面印迹材料的制备及其大分子识别特性

以交联聚乙烯醇(CPVA)微球为基质,采用接枝聚合和表面印迹同步技术制备碱性蛋白胰蛋白酶(TRY)分子表面印迹材料,甲基丙烯酰氯与CPVA微球表面的羟基发生快速酯化反应,得到表面含大量可聚合双键甲基丙烯酰基(MAO)的改性微球MAO-CPVA. 按一定摩尔比将TRY和单体阴离子单体对苯乙烯磺酸钠(SSS)溶解在水溶液中,加入交联剂N,N'-亚甲基双丙烯酰胺(MBA), MAO-CPVA分散于水介质中,过硫酸铵/亚硫酸氢钠引发体系产生自由基,使包围在TRY周围的单体SSS与MBA在MAO-CPVA表面发生接枝交联聚合,制得TRY表面印迹微球MIP-PSSS/CPVA,对其进行表征,考察了其大分子识别性能. 结果表明,MIP-PSSS/CPVA对TRY有优良的亲和性和特异识别选择性,吸附容量达85.9 mg/g,对TRY的选择性系数相对于蛋白溶菌酶LZM达17.52.     

阿司匹林载药淀粉微球吸附热力学和释药动力学的研究

以可溶性淀粉为原料,研究了淀粉微球在反相悬浮体系中不同温度下对阿司匹林的吸附行为,并考察其体外释放情况.结果表明：在实验条件范围内淀粉微球对阿司匹林的吸附量随着阿司匹林浓度的增加而增加.浓度相同时,温度越低,淀粉微球的吸附量也越大.吸附行为更符合Langmuir吸附模型,吸附为自发不可逆过程.总熵变是负值,焓变是主要的吸附驱动力.体外释放结果表明,阿司匹林淀粉微球聚合物在酸性介质中的释放行为更符合Higuchi方程,阿司匹林载药淀粉微球具有缓释作用.     

壳聚糖表面胰蛋白酶分子印迹聚合物的制备及性能的研究

在壳聚糖表面通过希夫碱反应嫁接一层戊二醛,形成核-壳结构微球。然后在这个核-壳微球上,以胰蛋白酶为模板分子,3-氨基苯硼酸为功能单体,制备了胰蛋白酶分子印迹聚合物,通过静态吸附法,研究了聚合物的吸附性能。结果表明,印迹聚合物对模板分子有较高吸附容量和特异选择性。为从蛋白质混和溶液中分离富集胰蛋白酶提供了新的材料和方法。     

Preparation and characterization of magnetic poly(styrene–glycidyl methacrylate) microspheres for highly efficient protein adsorption by two‐stage dispersion polymerization

Micrometer‐sized superparamagnetic poly(styrene–glycidyl methacrylate)/Fe₃O₄ spheres were synthesized by two‐stage dispersion polymerization with modified hydrophobic Fe₃O₄ nanoparticles, styrene (St), and glycidyl methacrylate (GMA). The morphology and properties of the magnetic Fe₃O₄–P (St‐GMA) microspheres were examined by scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry, thermogravimetric analysis, and attenuated total reflectance. The average size of the obtained magnetic microspheres was 1.50 μm in diameter with a narrow size distribution, and the saturation magnetization of the magnetic microspheres was 8.23 emu/g. The magnetic Fe₃O₄–P (St‐GMA) microspheres with immobilized iminodiacetic acid–Cu²⁺ groups were used to investigate the adsorption capacity and selectivity of the model proteins, bovine hemoglobin (BHb) and bovine serum albumin (BSA). We found that the adsorption capacity of BHb was as high as 190.66 mg/g of microspheres, which was 3.20 times greater than that of BSA, which was only 59.64 mg/g of microspheres as determined by high‐performance liquid chromatography. With a rather low nonspecific adsorption, these microspheres have great potential for protein separation and purification applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43005.     

氨基功能化聚苯乙烯纳米微球的制备及其CO2吸附性能研究

以苯乙烯(St)和甲基丙烯酸缩水甘油酯(GMA)为共聚单体,通过细乳液聚合法制备出聚苯乙烯纳米微球,并研究了单体配比与反应条件对纳米微球粒径大小与分布的影响。然后利用GMA上的活性环氧基团将有机胺接枝到纳米微球表面,并将其应用于CO2吸附。采用动态激光散射、扫描电子显微镜、红外光谱、元素分析等方法对纳米微球进行了结构表征。结果表明,所制备的纳米微球最小粒径为67 nm,粒径大小均一可控,而且纳米微球表面成功地接枝上有机胺;乙二胺改性纳米微球的CO2吸附量为2.45 mmol/g,并且吸附循环稳定性较好。     

Purification of biomolecules combining ATPS and membrane chromatography

Upstream processes for production of therapeutic proteins have been innovated and fermentation processes have been adopted for the use of recombinant microorganisms with high expression, but the downstream process is still the bottleneck in the biotechnological manufacturing process. A combined process consisting of aqueous two phase extraction (ATPE) and membrane chromatography is suggested to debottleneck downstream processing. ATPE has a large capacity, but the yield of the target product is from 74% to 97%. For this reason the product of ATPE waste stream is captured by membrane chromatography. In this work the binding capacity for the protein on protein A, ion exchange and hydrophobic exchange membrane chromatography was investigated experimentally with different concentration of polyethylene glycol (PEG), salt and protein. Protein A membrane was loaded with solutions resembling waste streams of ATPE for purifying IgG. For ion exchange and hydrophobic interaction membrane chromatography, the membrane was loaded with bovine serum albumin (BSA). PEG shows no significant effect on stability and capacity of membrane process. Even for small amount of BSA/IgG and high salt concentrations membrane adsorption is applicable. In this work it is demonstrated experimentally that a total product recovery of 99.9% for the purification of monoclonal antibody is possible.     

Preparation of Anti‐Nonspecific Adsorption Chitosan‐Based Bovine Serum Albumin Imprinted Polymers with Outstanding Adsorption Capacity and Selective Recognition Ability Based on Magnetic Microspheres

Bovine serum albumin (BSA)‐imprinted magnetic microspheres are successfully fabricated by a precipitation copolymerization, in which 2‐hydroxyethyl acrylate (HEA) and water‐soluble chitosan separately work as functional monomers and cross‐linking agents. Hydroxyl derived from HEA as well as hydroxyl, amino, and carboxyl groups, originating from chitosan on the surface of the prepared imprinted microspheres, can form hydrogen bonds and extra electrostatic interaction with proteins. The sulfobetaine methacrylate (SBMA) is introduced into the imprinted polymer as an anti‐protein segment to reduce the nonspecific adsorption and improve the selectivity. Detailed characterization demonstrates that the imprinted layer is about 10 nm, which is extremely beneficial for BSA identification and quality transmission. Furthermore, these microspheres also display an excellent selective adsorption of BSA (IF = 5.0). The results reveal that the prepared imprinted materials can be used as BSA biosensor or separation materials.     

Preparation of polymer‐supported polyethylene glycol and phase‐transfer catalytic activity in benzoate synthesis

The crosslinked polymeric microspheres (GMA/MMA) of glycyl methacrylate (GMA) and methyl methacrylate (MMA) were prepared by suspension polymerization. Polyethylene glycol (PEG) was grafted on GMA/MMA microsphers via the ring‐opening reaction of the epoxy groups on the surfaces of GMA/MMA microspheres, forming a polymer‐supported triphase catalyst, PEG‐GMA/MMA. The Phase‐transfer catalytic activity of PEG‐GMA/MMA microspheres was evaluated using the esterification reaction of n‐chlorobutane in organic phase and benzoic acid in water phase as a model system. The effects of various factors on the phase transfer catalysis reaction of liquid–solid–liquid were investigated. The experimental results show that the PEG‐GMA/MMA microspheres are an effective and stable triphase catalyst for the esterification reaction carried out between oil phase and water phase. The polarity of the organic solvent, the ratio of oil phase volume to water phase volume and the density of the grafted PEG on PEG‐GMA/MMA microspheres affect the reaction rate greatly. For this investigated system, the solvent with high polarity is appropriate, an adequate volume ratio of oil phase to water phase is 2:1, and the optimal PEG density on the polymeric microspheres is 15 g/100 g. Triphase catalysts offer many advantages associated with heterogeneous catalysts such as easy separation from the reaction mixture and reusability. The activity of PEG‐GMA/MMA microspheres is not nearly decreased after reusing of 10 recycles. © 2009 American Institute of Chemical Engineers AIChE J, 2010     

Inhibition of bovine serum albumin adsorption by poly(ethylene glycol) soft segment in biodegradable poly(ethylene glycol)/poly(L-lactide) copolymers

The objective of this study was to investigate the effects of the incorporation of ether linkages into polylactide (PLLA) chains and the time of biodegradation on the behavior of protein adsorption. The content of poly(ethylene glycol) (PEG) in PLLA/PEG copolymers is from 4.4 to 18.3 wt %, and the length of the PEG soft segment is 1000, 2000, and 6000 daltons. The bovine serum albumin (BSA) adsorption onto the biodegradable PLLA/PEG copolymers was carried out using ultraviolet spectroscopy. The surface tension of PLLA and PLLA/PEG was measured using a contact angle. The data show that the incorporation of PEG segments makes the copolymer more polar and, therefore, leads to a reduction of protein adsorption. As the hydrolysis of polymers proceeds, both PLLA and PLLA/PEG turn out to be more polar. However, the initial compositions of degraded PLLA/PEG have a weak influence on the protein adsorption onto its hydrolyzed surface with a substantially long duration of hydrolysis. This phenomenon is attributed to the hydrophobic interaction between polar PLLA/PEG and BSA. © 1993 John Wiley & Sons, Inc.     

Hydrous-ferric oxide nanorods grown on PEGylated graphene oxide with superior capacity for selective adsorption of albumin

A ferrate functionalized graphene-based composite is prepared by growth of hydrous ferric oxide (FeOOH) on the polyethylene glycol (PEG) modified graphene oxide (GO) sheets. The obtained GO–PEG–FeOOH composite is characterized by ATR-FTIR, TEM, AFM, XPS and ICP-MS. The PEGylation significantly changes the surface property of the bare graphene oxide, which not only generates a nano-bio-interface for protein interaction but also reduces the non-specific adsorption of proteins. The PEGylation and growth of FeOOH nanorods on GO sheets obviously enhanced the selectivity toward the adsorption of albumin through strong hydrogen bonding interaction, exhibiting an ultra-high adsorption capacity of 1377.4 mg g⁻¹ for bovine serum albumin (BSA). It is obviously higher than those achieved by any hitherto reported graphene based materials and other carbon nanomaterials. Albumin retained by the composite could be effectively recovered with a 4.0 mM B–R buffer through the affinity of boronic acid toward protein, giving rise to a recovery of 70%. Circular dichroism (CD) spectra indicate no conformational change for BSA during the process of adsorption/desorption. The practical applicability of the GO nanocomposite is further demonstrated by the selective adsorption/isolation of albumin from complex biological samples matrixes, e.g., human whole blood.     

Solid-phase DNA isolation from food matrices using hydrophilic magnetic microspheres

Dynamic light scattering (DLS) was used to monitor the coil–globule transition of calf thymus and bacterial DNAs by poly(ethylene glycol) (PEG 600 and PEG 6000) in aqueous NaCl solutions. The contribution of PEG 600 and PEG 6000 to DNA coil diameter change was investigated. Compaction of DNA molecules was observed for a PEG 6000 concentration ranging from 5.5 to 8%. Hydrophilic non-porous poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) – P(HEMA-co-GMA), poly(2-hydroxyethyl methacrylate-co-ethylene dimethacrylate) – P(HEMA-co-EDMA), and poly(glycidyl methacrylate) (PGMA) microspheres containing carboxyl groups were used for DNA isolation. The highest DNA yield was achieved using 16% PEG 6000 and 2.0 M NaCl. The amount of isolated DNA correlated with the content of carboxyl groups on the microsphere surface. RNA adsorption on the surface of the microspheres tested was also studied. RNA recovery was more than one order lower than DNA recovery under the same conditions. All types of microspheres were tested for DNA isolation from crude cell lysates of different dairy products in solutions of 16% PEG 6000 and 2.0 M NaCl. Isolated DNAs were without PCR inhibitors, which was demonstrated using real-time PCR including melting analysis of the amplicons.     

氧化硅片表面配基疏水性及含量对蛋白质吸附行为的影响

采用双偏振极化干涉分析技术研究了氧化硅片表面配基疏水性及含量对蛋白质质吸附行为的影响,用3种不同疏水性配基3-(氨丙基)三乙氧基硅烷(APTES)、3-(N-甲氨基丙基)三甲氧基硅烷(MAPTMS)和3-(N,N-二乙基氨丙基)三甲氧基硅烷(DAPTMS)修饰氧化硅片,通过修饰时间控制硅片表面配基含量,研究了配基疏水性对牛血清白蛋白质(BSA)的影响和配基含量(N含量)对BSA、细胞色素C和糜蛋白酶吸附行为的影响. 结果表明,BSA在疏水性最强的DAPTMS修饰的氧化硅表面吸附量及吸附动力学常数最大,分别为1.371 ng/mm2和0.056 s?1; DAPTMS含量对3种蛋白质吸附的影响与蛋白质疏水性密切相关,疏水性中等的BSA和细胞色素C为单分子层吸附,吸附量随N含量增加先增大后减小,N含量2.1%时吸附量最大,分别为16.9和60.2 nmol/m2. 疏水性较强的糜蛋白酶为多分子层吸附,吸附量随N含量增大而减小,N含量1.1%时吸附量及吸附动力学常数分别为78.6 nmol/m2和0.040 s?1.     

Hydrophilization of gigaporous polystyrene microspheres with saccharide as high-speed protein chromatography base support

Gigaporous poly(styrene–divinylbenzene) (PS) microspheres were hydrophilically modified with natural saccharide to minimize their nonspecific adsorption to proteins. The microspheres were chloroacetylated through Friedel–Crafts acetylation with chloroacetyl chloride, and then coupled with diacetone-D-glucose (DAGlu) through the Williamson reaction, and the protecting groups were removed on DAGlu. Results showed that the PS microspheres were successfully coupled with DAGlu and that the gigaporous structure was well maintained. After hydrophilization (Glu-PS), nonspecific adsorption of proteins on PS microspheres was greatly reduced. The high surface density of hydroxyl groups on Glu-PS microspheres surface make it easy to derivatize the spheres by classical methods. Flow experiments showed that the Glu-PS column had low backpressure, good permeability, and mechanical stability. All results indicate that the Glu-PS microspheres have great potential applications in high-speed protein chromatography.