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.     

聚合物表面引发接枝聚合

聚合物可以用臭氧氧化,其表面形成过氧化物密度可用碘化物、DPPH 和过氧化酶三种方法测定。经臭氧氧化后的 PU 膜表面可接技共聚 AAm,使其表面的物理及生物性能得到改进。     

载体材料表面化学组成对蛋白质吸附行为的影响研究进展

蛋白质在载体表面的吸附行为,如其吸附速率、吸附量以及取向和构象的变化,在很大程度上依赖于载体材料的表面化学组成。调控载体材料的表面化学组成已成为控制蛋白质吸附行为的重要手段。本文主要对载体材料表面不同组成对蛋白质吸附行为的影响进行了归纳。介绍了材料表面的功能基团包括疏水基团（甲基和含氟基团）和亲水基团（羟基、氨基和羧基）对蛋白质吸附行为的影响。另外,在载体材料表面接枝聚合物链是一种常用的有效调控表面化学组成的方法。重点介绍了材料表面接枝不同聚合物链时,聚合物链的种类、长度、密度和链的结构对蛋白质吸附行为的影响。     

多肽配基亲和吸附介质的配基密度控制规律

以谷胱甘肽为配基,琼脂糖微球为骨架,探索将谷胱甘肽通过共价键偶联到琼脂糖微球骨架上,制备可以分离谷胱甘肽S转移酶(Glutathione S-transferase, GST)及以其为标签的融合蛋白的亲和吸附介质.采用正交实验方法考察了谷胱甘肽加入量、偶联缓冲液的pH值和反应温度对亲和介质配基密度的影响.结果发现,该反应过程中的pH值对配基密度影响最大,其次为谷胱甘肽的加入量.用所制备的亲和吸附介质纯化GST(大鼠肝脏谷胱甘肽S转移酶),发现GST的吸附量随配基密度增加而增加,但GST活性却随配基密度的增加而下降,较好的干胶配基密度为260 μmol/g.大鼠肝匀浆液经过离子交换和亲和层析两个步骤,获得了电泳纯的GST,比活力为12.08 U/mg,总活性回收率为40%以上.     

聚合物接枝改性及接枝率的表征

综述了聚合物接枝改性的几种常见方法。如溶液接枝聚合、悬浮接枝聚合、超声波引发接枝聚合、超临界流体技术引发接枝聚合等,介绍了接枝聚合原理、研究和应用,并总结了接枝改性聚合物接枝率的表征方法,包括酸碱滴定法、傅里叶红外光谱（FTIR）、X射线衍射图谱分析（XRD）和元素分析法等。     

膨胀床吸附层析及其在生化分离中的应用

膨胀床是稳定无返混的流化床,它可直接从料液中吸附目标产物,不需预先除去料液中的颗粒。膨胀床将料液的澄清、浓缩和初步纯化集成于一个单元操作中,大大降低了分离过程的复杂程度,提高分离效率。吸附剂的物性、膨胀床装置、料液的性质以及操作条件等因素对膨胀床的稳定和分离效率有很大的影响。     

一种新的生物分离方法——混合模式吸附层析

混合模式吸附层析是一种新型的生物分离方法,其功能配基兼有两种或两种以上的作用模式,主要为静电和疏水相互作用。在低盐和高盐条件下,都可以实现对目标物的有效吸附,具有明显的耐盐吸附的特性,可避免对料液的额外预处理,从而提高分离效率,减少分离成本,已获得一定的应用。本文对混合模式吸附技术的发展历程、类型及应用现状等进行综述,以推动该技术的发展和进一步应用。     

辐射接枝改性聚合物的研究进展

本文介绍了辐射接枝技术改性聚合物的研究与应用情况，并讨论了辐射接枝过程中的主要影响因素。     

阻抗蛋白质吸附材料研究进展

蛋白质是两亲大分子,对材料表面具有亲和性,易被吸附并污染材料。阻抗蛋白质吸附的无污染表面在生物医药、船体涂层、生物芯片等领域具有广泛重要的应用。本文对聚合物材料表面阻抗蛋白质吸附的机理进行了归纳,介绍了阻抗蛋白质吸附的材料制备及表面修饰的相关研究进展。     

反相聚合物填料层析纯化万古霉素工艺研究

研究了反相聚合物填料层析纯化万古霉素工艺。得到了较佳工艺条件为：载样量3.5%,洗杂、洗脱流速2.25 BV·h^-1,先用3.5 BV的6%甲醇-水溶液洗杂,再用12%甲醇-水溶液洗脱。层析纯化后的万古霉素纯度由原来的93.20%提高到98.22%以上,收率达81%以上。该层析工艺降低杂质效果明显,可在较高的效率下获得高纯度万古霉素,有较高的应用价值。     

Surface DEAE groups facilitate protein transport on polymer chains in DEAE‐modified‐and‐DEAE‐dextran‐grafted resins

Sepharose FF was modified with diethylaminoethyl‐dextran (DEAE‐dextran, DexD) and/or DEAE (D) to fabricate three types of ion exchangers FF‐DexD (grafting‐ligand resin), FF‐D (surface‐ligand resin), and FF‐D‐DexD (mixed‐ligand resin), for protein adsorption equilibria and kinetics study. It was found that both adsorption capacity and uptake rate (effective diffusivity, D_e) were significantly enhanced by grafting DEAE‐dextran. Notably, the D_e values on FF‐DexD and FF‐D‐DexD (D_e/D₀ > 1.4) were six times greater than those on FF‐D (D_e/D₀ < 0.3). More importantly, the increase of surface‐ligand density greatly enhanced uptake kinetics on FF‐D‐DexD. The results indicate that the surface ligands assisted the transport of bound proteins on polymer chains in the mixed‐ligand resins. That is, surface ligands worked as “transfer stations” between two neighboring chains, resulting in enhanced transport of bound proteins on chains. The research thus disclosed the unique role of surface ligands in facilitating protein uptake kinetics onto polymer‐grafted ion‐exchangers. © 2016 American Institute of Chemical Engineers AIChE J, 62: 3812–3819, 2016     

等离子体引发微孔板接枝SMCC及蛋白吸附性能

用丙烯酰胺等离子体引发活化聚苯乙烯（PS）微孔板，接枝4-(N-马来酰亚胺基甲基)环己 烷-1-羧酸琥珀酰亚胺酯（SMCC）联接剂，制备了易于固定蛋白的PS-g-SMCC微孔板。利用FTIR、EDS、XPS、SEM、接触角测试仪和酶标仪对其表面组成、结构、形貌及蛋白吸附性能进行了表征。结果表明，PS微孔板表面成功接枝了丙烯酰胺与SMCC，当等离子体处理参数为500 W，300 s时，接枝丙烯酰胺的效果最好，PS-g-SMCC微孔板表面达到超亲水；当SMCC质量浓度为5 g/L 时，PS-g-SMCC微孔板对牛血清蛋白的吸附量最大，为903.08 ng/cm2，与未处理的PS微孔板相比，吸附量提高了2.93倍，有效提高了PS微孔板的检测灵敏性。     

Study on the surface properties of grafted polyethylene particles by inverse gas chromatography

Inverse gas chromatography (IGC) studies on the surface of polyethylene (PE) particles grafted with acrylic acid and acryl amide have been reported. Surface properties of the virgin and grafting‐modified PE were compared by IGC. The dispersive contributions of the surface free energy γ and the K_A and K_B parameters expressing the ability of the stationary phase to act as Lewis acid or Lewis base were calculated. The results showed that the γ value increased significantly after grafting. The PE samples grafted with acrylic acid and acrylamide showed a predominantly basic character while the virgin PE was acidic. All of these suggested that the surface of PE has been modified through the grafting reaction, and thus is expected to improve its adhesions with other polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Novel jute yarns grafted with methyl methacrylate

This research work involves graft copolymerization of jute fibers with methyl methacrylate (MMA), initiated by cerric ions, and optimization of the grafting parameters as a function of different polymerization conditions. It was considered to produce a hydrophobic jute fiber with enhanced properties. To achieve this, the effects of monomer concentration and grafting percentage on FTIR spectra, mechanical properties, moisture regain, oil‐adsorption capacity, and surface morphology were investigated, and optimum percentage of MMA with reasonable properties was suggested. The results indicated that cerric ions initiated graft copolymerization of MMA onto jute with 30% of weight of monomers at optimum conditions of acid concentration and temperature. The FTIR studies proposed grafting of MMA onto jute at hydroxyl groups. The results showed that mechanical properties and moisture regain (%) of samples decrease with increasing of graft percentage. The most remarkable features of this investigation include reducing oil‐adsorption capacity with increasing of lipophilic monomer percentages after one limitation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Hydrophobic charge-induction chromatographic resin with 5-aminobenzimidazol ligand: Effects of ligand density on protein adsorption

Hydrophobic charge-induction chromatography (HCIC) is a highly promising technology for antibody separation. HCIC resins ABI-B-6FF were prepared with 5-aminobenzimidazole (ABI) as the functional ligand. The effects of ligand density on the adsorption of human immunoglobulin G (hIgG) and bovine serum albumin were focused. It was found that the adsorption capacity and dynamic binding capacity (DBC) were improved with the increase of ligand density. The adsorption capacity and DBC of hIgG reached 128.07 mg/g gel and 67.63 mg/g gel. The results indicated that ABI-B-6FF resin has a promising potential for the application of antibody purification.     

Biporous polymeric beads fabricated by double emulsification for high‐speed protein chromatography

Rigid biporous beads (BiPB) were fabricated by double emulsification. An aqueous suspension of superfine calcium carbonate granules and organic solvent were used as porogenic agents to create superpores and micropores, respectively. The polymerization of monomers, glycidyl methacrylate, and ethylene glycol dimethacrylate was initiated with benzoin ethyl ether by ultraviolet irradiation. Modified with diethylamine (DEA), the BiPB were derivatized into an anion‐exchange medium (which is denoted as DEA–BiPB). The DEA–BiPB with an average diameter of 46.3 μm was characterized to possess two types of pores, that is, micropores (20–200 nm) and superpores (500–5300 nm). Flow hydrodynamic experiments showed that the DEA–BiPB column had a smaller backpressure than that of the conventional microporous beads column at a given flow rate. The static adsorption capacity of the DEA–BiPB was close to that of the DEA–MiPB for bovine serum albumin. However, frontal analysis demonstrated that the dynamic binding capacity of the DEA–BiPB column was two times higher than that of the DEA–MiPB at a flow rate of 1800 cm/h. Moreover, the purification of the molecular chaperone GroEL was carried out with the DEA–BiPB column at two flow rates (150 and 1500 cm/h). This showed that the GroEL purification was nearly the same at the two flow rates tested. These results indicate that the DEA–BiPB column is promising for high‐speed protein chromatography. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 17–23, 2007     

Influence of poly(acrylic acid) grafting density on switchable protein adsorption/desorption of poly(2-methyl-2-oxazoline)/poly(acrylic acid) mixed brushes

Poly(dopamine) is employed as an anchor to obtain a series of poly(acrylic acid) (PAA) and poly(2-methyl-2-oxazoline) (PMOXA) mixed brush coatings by sequential grafting to methods with PAA chains longer than PMOXA chains. Then, the prepared mixed brush coatings are rigorously characterized. The results show that the grafting density of PAA in mixed brushes could be well adjusted by changing the concentration of PAA solution used for the preparation of mixed brush coatings and the amounts of lysozyme adsorbed on PMOXA/PAA mixed brushes increase with increasing the grafting density of PAA chains while the desorption amounts decrease significantly when the grafting density of PAA is higher than one-half of PMOXA chains. When the grafting density of PAA is about one-half of PMOXA chains, the mixed brush could absorb high amounts of lysozyme (898.4 ng cm⁻²), and then more than 90% of adsorbed proteins could be released sharply by changing pH and ionic strength (I). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48135.     

亲和层析介质非特异性吸附的定量表征研究

针对亲和层析介质的非特异性吸附,基于脉冲响应法,建立了定量表征方法。以牛血清白蛋白、酵母发酵液和CHO细胞培养液作为典型杂质,考察了四种蛋白A亲和层析介质和两种基质微球,在不同pH和盐浓度条件下非特异性吸附。发现介质和基质对杂质均有不同程度的吸附,在酸性条件下非特异性吸附相对较强。对于不同料液,存在不同的杂质吸附机制,可通过静电、疏水作用或两者共同作用结合。两种介质和基质的比较结果表明,琼脂糖基介质的非特异性吸附主要依赖其基质微球与杂质间相互作用,而聚甲基丙烯酸酯基介质对杂质的吸附作用强于其基质微球。结果表明,本文建立的非特异性吸附定量表征方法切实可行,可用于量化表征介质非特异性吸附,探究相关作用机制,为介质研发提供新的分析方法和依据。     

Cellulose membranes grafted with vinyl monomers in homogeneous system

The homogeneous grafting of a hydrophilic monomer onto cellulose derivatives was carried out in an aqueous system at 30, 50, 70, and 90°C during reaction periods of 30–180 min. The graft polymer was isolated by ethanol from the reaction mixture, dried, and weighed. The grafted polymer was characterized by the IR method, as well as the microscopic sample morphology detected by scanning electron microscopy. The water absorption capacities and grafting values of the grafted cellulose derivatives were also determined. The maximum grafting yield was obtained at 30°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2629–2638, 2002