Novel photochemical surface functionalization of polysulfone ultrafiltration membranes for covalent immobilization of biomolecules
Novel photochemical surface functionalization of polysulfone ultrafiltration membranes for covalent immobilization of biomolecules
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DOI：
10.1016/0376-7388(96)00148-2
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发表时间：
1996-11
影响因子：
9.5
通讯作者：
M. Ulbricht;M. Riedel;U. Marx
中科院分区：
文献类型：
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作者：
M. Ulbricht;M. Riedel;U. Marx
工作的主要目的是开发一种用于连接反应基团的非均相修饰方法，适用于在聚砜超滤器表面上共价固定活性生物分子而不损失膜选择性。为了应用聚合物特异性活化化学，使用元素分析沿着1H NMR、FTIR-ATR和UV光谱鉴定商业“聚砜”UF膜的材料。以丙烯酸（AA）为模型单体和反应基团载体，实现了非均相光引发接枝聚合。聚合物结构（聚砜，PSf或聚醚砜，PESf）、光引发剂涂层（二苯甲酮，BP或苯甲酰基苯甲酸，BPC）和UV激发能量（λ exc 220> 300或350 nm）是主要参数。接枝聚AA（g-PAA）可以在几乎所有的条件下，但在很大程度上不同的收率（DG）。然而，只有在λ ex 350 nm时，才能排除聚合物和孔降解。间接证明了一种新的选择性引发PSf接枝聚合的方法，即光激发BP衍生物从甲基侧基上夺氢，从而避免聚合物断链。改性的结构进行了光谱表征，包括可视化与SFM的横向图案化的表面产生的UV照射通过掩模。在“轻度降解”条件（λ exc 300 nm）下制备的PSf-g-PAA和PESf-g-PAA UF膜（DG = 100. 150 μg/cm 2）的UF测试表明，与未改性的样品相比，仅轻微的渗透性和选择性变化。选择性PSf功能化（BPC涂层，λ exc 350 nm; DG 5 μg/cm 2）导致通量降低，葡聚糖选择性增加1.3倍。用蛋白质（BSA）、酶（转化酶，INV）、抗体-酶（IgG-POD）缀合物和肽（“PC 1”）作为单克隆抗体的特异性抗原，研究了共价固定到g-PAA官能化的和马来酰亚胺活化的PSf或PESf膜表面上。直接（BSA）或通过比活性/结合测定（INV、IgG-POD、“PC 1”）间接检测到高结合能力，与未经修饰的平坦表面相比高达40倍。这表明由于多官能反应性和亲水性接枝聚合物链，外膜表面积增加。
The major objective of the work was to develop a heterogeneous modification method for attachment of reactive groups, suitable for covalent immobilization of active biomolecules on the surface of polysulfone ultrafilters without loss of membrane selectivity. For applying a polymer specific activation chemistry, the materials of commercial “polysulfone” UF membranes were identified using elemental analysis along with1H NMR, FTIR-ATR and UV spectroscopy. Heterogeneous photoinitiated graft polymerization was realized using acrylic acid (AA) as model monomer and as carrier of reactive groups. Polymer structure (polysulfone, PSf, or polyethersulfone, PESf), coating with photoinitiator (benzophenone, BP, or benzoylbenzoic acid, BPC) and UV excitation energy (λexc220 > 300 or 350 nm) were the major parameters. Grafted polyAA (g-PAA) could be obtained under almost all conditions but with largely varying yields (DG). However, only with λexc350 nm, polymer and pore degradation could be excluded. A new selective initiation of graft polymerization onto PSf, H-abstraction by photoexcited BP derivatives from the methyl side groups, thus avoiding polymer chain scission, was proved indirectly. Modified structures were characterized spectroscopically, including visualization with SFM of laterally patterned surfaces generated by UV irradiation through a mask. UF tests of PSf-g-PAA and PESf-g-PAA UF membranes (DG ∼ 100…150 μg/cm2), prepared under “mildly degrading” conditions (λexc300 nm), indicated only slight permeability and selectivity changes compared with unmodified samples. Selective PSf functionalization (BPC coating, λexc350 nm; DG 5 μg/cm2) caused flux reductions and dextran selectivity increases by factors of ∼ 1.3. Covalent immobilization onto g-PAA-functionalized and carbodiimide-activated PSf or PESf membrane surfaces was studied with a protein (BSA), an enzyme (invertase, INV), an antibody-enzyme (IgG-POD) conjugate, and a peptide (“PC1”) as specific antigen of a monoclonal antibody. High binding capacities, up to 40 fold compared with a flat unmodified surface, were detected either directly (BSA) or indirectly via specific activity/binding assays (INV, IgG-POD, “PC1”). This indicated an increased outer membrane surface area due to multifunctional reactive and hydrophilic grafted polymer chains.