Achieving highly effective nonfouling performance for surface-grafted poly(HPMA) via atom-transfer radical polymerization

Human blood plasma and serum pose significant challenges to implanted devices because of highly unfavorable nonspecific protein adsorption on the surface. In this work, we introduce an improved two-step method to immobilize initiator thiols on a gold substrate for the surface-initiated atom-transfer radical polymerization (SI-ATRP) of hydroxypropyl methacrylate (HPMA). We investigate protein adsorption from a single-protein solution, diluted (10%) and undiluted (100%) human blood plasma, and serum on the poly(HPMA) brushes with different film thicknesses using surface plasmon resonance (SPR) sensors. SPR results show a correlation between antifouling properties and film thickness; that is, the poly(HPMA) brushes exhibit high protein resistance at medium film thicknesses of ～25-40 nm (e.g. <0.3 ng/cm(2) for single-protein adsorption and 10% human blood plasma and serum, ～24.5 ng/cm(2) for 100% human serum, and ～52.8 ng/cm(2) for 100% human plasma at a thickness of ～29 nm). With an optimal film thickness and surface roughness, the poly(HPMA) brush also demonstrates its high resistance to fibroblast adhesion. This work provides an alternative surface polymerization approach to preparing effective antifouling poly(HPMA) materials for potential applications in blood-contacting medical devices.     

Film thickness dependence of protein adsorption from blood serum and plasma onto poly(sulfobetaine)-grafted surfaces

In this work, we investigate protein adsorption from single protein solutions and complex media such as 100% blood serum and plasma onto poly(sulfobetaine methacrylate) (polySBMA)-grafted surfaces via atom transfer radical polymerization (ATRP) at varying film thicknesses. It is interesting to observe that protein adsorption exhibits a minimum at a medium film thickness. Results show that the surface with 62 nm polySBMA brushes presents the best nonfouling character in 100% blood serum and plasma although all of these surfaces are highly resistant to nonspecific protein adsorption from single fibrinogen and lysozyme solutions. Surface resistance to 100% blood serum or plasma is necessary for many applications from blood-contacting devices to drug delivery. This work provides a new in vitro evaluation standard for the application of biomaterials in vivo.     

Bioadhesive control of plasma proteins and blood cells from umbilical cord blood onto the interface grafted with zwitterionic polymer brushes

In this work, bioadhesive behavior of plasma proteins and blood cells from umbilical cord blood (UCB) onto zwitterionic poly(sulfobetaine methacrylate) (polySBMA) polymer brushes was studied. The surface coverage of polySBMA brushes on a hydrophobic polystyrene (PS) well plate with surface grafting weights ranging from 0.02 mg/cm(2) to 0.69 mg/cm(2) can be effectively controlled using the ozone pretreatment and thermal-induced radical graft-polymerization. The chemical composition, grafting structure, surface hydrophilicity, and hydration capability of prepared polySBMA brushes were determined to illustrate the correlations between grafting properties and blood compatibility of zwitterionic-grafted surfaces in contact with human UCB. The protein adsorption of fibrinogen in single-protein solutions and at complex medium of 100% UCB plasma onto different polySBMA brushes with different grafting coverage was measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. The grafting density of the zwitterionic brushes greatly affects the PS surface, thus controlling the adsorption of fibrinogen, the adhesion of platelets, and the preservation of hematopoietic stem and progenitor cells (HSPCs) in UCB. The results showed that PS surfaces grafted with polySBMA brushes possess controllable hydration properties through the binding of water molecules, regulating the bioadhesive and bioinert characteristics of plasma proteins and blood platelets in UCB. Interestingly, it was found that the polySBMA brushes with an optimized grafting weight of approximately 0.1 mg/cm(2) at physiologic temperatures show significant hydrated chain flexibility and balanced hydrophilicity to provide the best preservation capacity for HSPCs stored in 100% UCB solution for 2 weeks. This work suggests that, through controlling grafting structures, the hemocompatible nature of grafted zwitterionic polymer brushes makes them well suited to the molecular design of regulated bioadhesive interfaces for use in the preservation of HSPCs from human UCB.     

A highly stable nonbiofouling surface with well-packed grafted zwitterionic polysulfobetaine for plasma protein repulsion

An ideal nonbiofouling surface for biomedical applications requires both high-efficient antifouling characteristics in relation to biological components and long-term material stability from biological systems. In this study we demonstrate the performance and stability of an antifouling surface with grafted zwitterionic sulfobetaine methacrylate (SBMA). The SBMA was grafted from a bromide-covered gold surface via surface-initiated atom transfer radical polymerization to form well-packed polymer brushes. Plasma protein adsorption on poly(sulfobetaine methacrylate) (polySBMA) grafted surfaces was measured with a surface plasmon resonance sensor. It is revealed that an excellent stable nonbiofouling surface with grafted polySBMA can be performed with a cycling test of the adsorption of three model proteins in a wide range of various salt types, buffer compositions, solution pH levels, and temperatures. This work also demonstrates the adsorption of plasma proteins and the adhesion of platelets from human blood plasma on the polySBMA grafted surface. It was found that the polySBMA grafted surface effectively reduces the plasma protein adsorption from platelet-poor plasma solution to a level superior to that of adsorption on a surface terminated with tetra(ethylene glycol). The adhesion and activation of platelets from platelet-rich plasma solution were not observed on the polySBMA grafted surface. This work further concludes that a surface with good hemocompatibility can be achieved by the well-packed surface-grafted polySBMA brushes.     

Hemocompatibility of poly(vinylidene fluoride) membrane grafted with network-like and brush-like antifouling layer controlled via plasma-induced surface PEGylation

In this work, the hemocompatibility of PEGylated poly(vinylidene fluoride) (PVDF) microporous membranes with varying grafting coverage and structures via plasma-induced surface PEGylation was studied. Network-like and brush-like PEGylated layers on PVDF membrane surfaces were achieved by low-pressure and atmospheric plasma treatment. The chemical composition, physical morphology, grafting structure, surface hydrophilicity, and hydration capability of prepared membranes were determined to illustrate the correlations between grafting qualities and hemocompatibility of PEGylated PVDF membranes in contact with human blood. Plasma protein adsorption onto different PEGylated PVDF membranes from single-protein solutions and the complex medium of 100% human plasma were measured by enzyme-linked immunosorbent assay (ELISA) with monoclonal antibodies. Hemocompatibility of the PEGylated membranes was evaluated by the antifouling property of platelet adhesion observed by scanning electron microscopy (SEM) and the anticoagulant activity of the blood coagulant determined by testing plasma-clotting time. The control of grafting structures of PEGylated layers highly regulates the PVDF membrane to resist the adsorption of plasma proteins, the adhesion of platelets, and the coagulation of human plasma. It was found that PVDF membranes grafted with brush-like PEGylated layers presented higher hydration capability with binding water molecules than with network-like PEGylated layers to improve the hemocompatible character of plasma protein and blood platelet resistance in human blood. This work suggests that the hemocompatible nature of grafted PEGylated polymers by controlling grafting structures gives them great potential in the molecular design of antithrombogenic membranes for use in human blood.     

Ultralow fouling zwitterionic polymers grafted from surfaces covered with an initiator via an adhesive mussel mimetic linkage

In this work, nonfouling zwitterionic polymers were grafted via surface-initiated atom transfer radical polymerization (ATRP) from surfaces covered with an adhesive catechol initiator. The catechol initiator was attached to both bare gold and amino-functionalized surfaces, and the nonfouling performances of the resulting polymer brushes were compared. Under optimal conditions, ultralow protein adsorption from both single-protein solutions of fibrinogen and lysozyme and complex media of 10% blood serum and 100% blood plasma/serum was achieved. Furthermore, the 3-day accumulation of Pseudomonas aeruginosa on the treated glass surfaces was studied in situ using a laminar flow chamber. The results showed that these zwitterionic coatings dramatically reduced the biofilm formation of P. aeruginosa as compared to the reference bare glass.     

Development of a novel antifouling platform for biosensing probe immobilization from methacryloyloxyethyl phosphorylcholine-containing copolymer brushes

The immobilization of thiol-terminated poly[(methacrylic acid)-ran-(2-methacryloyloxyethyl phosphorylcholine)] (PMAMPC-SH) brushes on gold-coated surface plasmon resonance (SPR) chips was performed using the "grafting to" approach via self-assembly formation. The copolymer brushes provide both functionalizability and antifouling characteristics, desirable features mandatorily required for the development of an effective platform for probe immobilization in biosensing applications. The carboxyl groups from the methacrylic acid (MA) units were employed for attaching active biomolecules that can act as sensing probes for biospecific detection of target molecules, whereas the 2-methacryloyloxyethyl phosphorylcholine (MPC) units were introduced to suppress unwanted nonspecific adsorption. The detection efficiency of the biotin-immobilized PMAMPC brushes with the target molecule, avidin (AVD), was evaluated in blood plasma in comparison with the conventional 2D monolayer of 11-mercaptoundecanoic acid (MUA) and homopolymer brushes of poly(methacrylic acid) (PMA) also immobilized with biotin using the SPR technique. Copolymer brushes with 79 mol % MPC composition and a molecular weight of 49.3 kDa yielded the platform for probe immobilization with the best performance considering its high S/N ratio as compared with platforms based on MUA and PMA brushes. In addition, the detection limit for detecting AVD in blood plasma solution was found to be 1.5 nM (equivalent to 100 ng/mL). The results have demonstrated the potential for using these newly developed surface-attached PMAMPC brushes for probe immobilization and subsequent detection of designated target molecules in complex matrices such as blood plasma and clinical samples.     

An experimental-theoretical analysis of protein adsorption on peptidomimetic polymer brushes

Surface-grafted water-soluble polymer brushes are being intensely investigated for preventing protein adsorption to improve biomedical device function, prevent marine fouling, and enable applications in biosensing and tissue engineering. In this contribution, we present an experimental-theoretical analysis of a peptidomimetic polymer brush system with regard to the critical brush density required for preventing protein adsorption at varying chain lengths. A mussel adhesive-inspired DOPA-Lys (DOPA = 3,4-dihydroxy-phenylalanine; Lys = lysine) pentapeptide surface grafting motif enabled aqueous deposition of our peptidomimetic polypeptoid brushes over a wide range of chain densities. Critical densities of 0.88 nm(-2) for a relatively short polypeptoid 10-mer to 0.42 nm(-2) for a 50-mer were identified from measurements of protein adsorption. The experiments were also compared with the protein adsorption isotherms predicted by a molecular theory. Excellent agreements in terms of both the polymer brush structure and the critical chain density were obtained. Furthermore, atomic force microscopy (AFM) imaging is shown to be useful in verifying the critical brush density for preventing protein adsorption. The present coanalysis of experimental and theoretical results demonstrates the significance of characterizing the critical brush density in evaluating the performance of an antifouling polymer brush system. The high fidelity of the agreement between the experiments and molecular theory also indicate that the theoretical approach presented can aid in the practical design of antifouling polymer brush systems.     

Improvement of hemocompatibility of polycaprolactone film surfaces with zwitterionic polymer brushes

Polycaprolactone (PCL) has been widely adopted as a scaffold biomaterial, but further improvement of the hemocompatibility of a PCL film surface is still needed for wide biomedical applications. In this work, the PCL film surface was functionalized with zwitterionic poly(3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate) (P(DMAPS)) brushes via surface-initiated atom transfer radical polymerization (ATRP) for enhancing hemocompatibility. Kinetics study revealed an approximately linear increase in graft yield of the functional P(DMAPS) brushes with polymerization time. The blood compatibilities of the modified PCL film surfaces were studied by platelet adhesion tests of platelet-rich plasma and human whole blood, hemolysis assay, and plasma recalcification time (PRT) assay. The improvement of hemocompatibility is dependent on the coverage of the grafted P(DMAPS) brushes on the PCL film. Lower or no platelet and blood cell adhesion was observed on the P(DMAPS)-grafted film surfaces. The P(DMAPS) grafting can further decrease hemolysis and enhance the PRT of the PCL surface. With the versatility of surface-initiated ATRP and the excellent hemocompatibility of zwitterionic polymer brushes, PCL films with desirable blood properties can be readily tailored to cater to various biomedical applications.     

Crystallization kinetics of polymer brushes with poly(ethylene oxide) side chains

Isothermal crystallization rates of semicrystalline poly(methoxypoly(ethylene glycol) methacrylate) brushes on gold‐coated substrates were measured by polarized optical microscopy. Growth rates for crystal radii, which were essentially constant for each film, initially increased with film thickness and then leveled off for film thicknesses >300 nm. Avrami–Evans theory suggests that the spherulites exhibit one‐dimensional growth with heterogeneous nucleation. Compared with physisorbed analogs, polymer brushes crystallized slower due to the restriction of chain mobility. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1955–1959, 2010     

Surface chemistry to minimize fouling from blood-based fluids

Upon contact with bodily fluids/tissues, exogenous materials spontaneously develop a layer of proteins on their surface. In the case of biomedical implants and equipment, biological processes with deleterious effects may ensue. For biosensing platforms, it is synonymous with an overwhelming background signal that prevents the detection/quantification of target analytes present in considerably lower concentrations. To address this ubiquitous problem, tremendous efforts have been dedicated over the years to engineer protein-resistant coatings. There is now extensive literature available on stealth organic adlayers able to minimize fouling down to a few ng cm(-2), however from technologically irrelevant single-protein buffered solutions. Unfortunately, few coatings have been reported to present such level of performance when exposed to highly complex proteinaceous, real-world media such as blood serum and plasma, even diluted. Herein, we concisely review the surface chemistry developed to date to minimize fouling from these considerably more challenging blood-based fluids. Adsorption dynamics is also discussed.     

Elucidation of the mechanism of surface‐initiated atom transfer radical polymerization from a diazonium‐based initiator layer

This study elucidates the influence of the atom transfer radical polymerization initiator structure, monolayer versus disordered multilayer, on the growth kinetics and the structural transition of poly(methyl methacrylate) (PMMA) brush layers. The multilayer initiator film, prepared by acylation of the electrografted 2‐phenylethanol layer using 2‐bromoisobutyryl bromide, consists of ～4.6 times more tert‐butyl bromide groups compared to monolayer initiator prepared by self assembly technique. The results demonstrate the formation of precursor complex between Cu^I catalyst and the bromine initiator as a prerequisite step before the onset of polymerization. Furthermore, the PMMA brushes formed by the polymerization from the multilayered initiator layer at 50 °C are 20‐fold thicker compared to the polymerization at 25 °C due to the swelling of the multilayered initiator film. In contrast, the thickness of the PMMA layer on the monolayer initiator is less affected by the polymerization temperature. By varying the initiator density on the surface, the solvent content in the PMMA layer is shown to vary from 15% to 94%, resulting in the transition from concentrated over semidiluted to diluted brushes. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Polymer brushes in nanopores surrounded by silicon-supported tris(trimethylsiloxy)silyl monolayers

A chemically grafted tris(trimethylsiloxy)silyl (tris(TMS)) monolayer on a silicon oxide substrate was used as a template for creating nanoclusters of polymer brushes. Polymer brushes were synthesized by surface-initiated polymerization of 2-methacryloyloxyethyl phosphorylcholine (MPC) and tert-butyl methacrylate (t-BMA) via atom transfer radical polymerization (ATRP) from alpha-bromoester groups tethered to the residual silanol groups on the silicon surface after generating a range of tris(TMS) coverage. CuBr/bpy and CuBr/PMDETA were used as the catalytic system for PMPC and Pt-BMA synthesis, respectively. The percentage of tris(TMS) coverage significantly influenced the thickness and morphology of the polymer brushes. Protrusions representing self-aggregation of PMPC brushes in nanopores as visualized by AFM analysis evidently suggested that PMPC brushes were distributed nanoscopically on the surface. The protrusion size and surface roughness corresponded quite well with the graft density of PMPC brushes. The fact that Pt-BMA brushes grown from nanopores were almost featureless implies that self-aggregation of PMPC brushes is truly a consequence of phase incompatibility between hydrophilic PMPC brushes and hydrophobic tris(TMS). The anti-fouling characteristic of PMPC brushes, inferred from plasma protein adsorption, was subsequently varied by controlling the surface coverage ratio between PMPC brushes and tris(TMS).     

表面温敏聚合物刷的原子力显微镜和石英晶体微天平研究

通过表面引发的原子转移自由基聚合在硅片表面制备了聚（N-异丙基丙烯酰胺）（PNIPAAm）聚合物刷。用原子力显微镜（AFM）分别研究了PNIPAAm的接枝动力学、温度和溶剂性质对厚度的影响以及PNIPAAm链与原子力针尖间的粘附力。结果表明,PNIPAAm链在硅片表面的生长具有很好的可控性。常温下厚度为33nm的PNIPAAm膜在水溶液中的增加到82.4nm;而在甲醇/水（v/v,1:1）溶液中,PNIPAAm分子链处于坍塌收缩状态,厚度降低为45nm;在55℃下干燥所得厚度则仅为22nm。力-距离测量结果表明,在溶液中,PNIPAAm链与原子力针尖之间的粘附力远小于在干态下的粘附力。用石英晶体微天平（QCM-D）对PNIPAAm的可逆相转变进行了研究,结果表明PNIPAAm分子链随温度变化的构象转变是发生在30-34℃之间的连续过程。     

Formation of antifouling functional coating from deposition of a zwitterionic-co-nonionic polymer via “grafting to” approach

We develop a new process for the preparation of synergistic antifouling functional coatings on gold surfaces via a “grafting to” approach. The strategy includes a synthetic step of polymer brushes that consist of poly (ethylene glycol) (PEG) and zwitterionic side chains via a typical reversible-addition fragmentation chain transfer (RAFT) polymerization process, and a subsequent deposition of the polymer brushes onto a gold substrate. The presence of PEG and zwitterion chains on these polymer brush-coated gold surfaces has been proved to have a synergistic effect on the final antifouling property of the coating. PEG chains lower the electrostatic repulsion between zwitterionic polymer chains and increase their graft density on gold surfaces, while zwitterionic polymer effectively improves the antifouling property that is offered by PEG chains alone. Protein adsorption and cell attachment assays tests are conducted to confirm that this copolymer layer on gold surface has a pronounced resistance against proteins such as Bovine serum albumin and Lysozyme. Importantly, the antifouling property can be systematically adjusted by varying the molar ratio of PEG to zwitterionic chains in the final coating copolymer.     

Size-Exclusion Effect and Protein Repellency of Concentrated Polymer Brushes Prepared by Surface-Initiated Living Radical Polymerization

The adsorption of proteins on poly(2-hydroxyethyl methacrylate) (PHEMA) brushes was systematically investigated from the viewpoint of the size-exclusion effect of the concentrated brushes. By use of surface-initiated atom transfer radical polymerization, well-defined, concentrated PHEMA brushes were successfully grafted on the inner surface of the silica monolithic column with meso pores of ca. 80 nm as well as a silicon wafer and a quartz crystal microbalance (QCM) chip. By eluting low-polydispersity pullulans with different molecular weight through the modified monolithic column, the concentrated PHEMA brush was characterized and demonstrated to sharply exclude solute molecules with the critical molecular size (size-exclusion limit) comparable to the distance between the nearest-neighboring graft points d. The elution behaviors of proteins with different sizes were studied with this PHEMA-grafted column: the protein sufficiently larger than the critical size was perfectly excluded from the brush layer and separated only in the size-exclusion mode by the meso pores without affinity interaction with the brush surface. Then, the irreversible adsorption of proteins on PHEMA brushes was investigated using QCM by varying graft densities (σ = 0.007, 0.06, and 0.7 chains/nm²) and protein sizes (effective diameter = 2–13 nm). A good correlation between the protein size and the graft density was observed: proteins larger than d caused no significant irreversible adsorption on the PHEMA brushes. Thus, we experimentally substantiated the postulated size-exclusion effect of the concentrated brushes and confirmed that this effect plays an important role for suppressing protein adsorption.     

Surface grafted sulfobetaine polymers via atom transfer radical polymerization as superlow fouling coatings

One of the sulfobetaine methacrylate (SBMA) monomers, N-(3-sulfopropyl)-N-(methacryloxyethyl)-N,N-dimethylammonium betaine, was polymerized onto initiator-covered gold surfaces using atom transfer radical polymerization (ATRP) to form uniform polymer brushes. Self-assembled monolayers (SAMs) with ATRP initiators were characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). The thickness of grafted poly(SBMA) films was measured by ellipsometry. Fibrinogen adsorption on poly(SBMA) grafted surfaces was measured with a surface plasmon resonance (SPR) sensor. Two approaches were compared to graft ATRP initiators onto gold surfaces for surface polymerization and subsequent protein adsorption on these polymer grafted surfaces. The first was to prepare a SAM from omega-mercaptoundecyl bromoisobutyrate onto a gold surface. Superlow fouling surfaces with well-controlled poly(SBMA) brushes were achieved using this approach (e.g., fibrinogen adsorption <0.3 ng/cm2). The second approach was to react bromoisobutyryl bromide with a hydroxyl-terminated SAM on a gold surface. Although protein adsorption decreased as the density of surface initiators increased, the surface prepared using the second approach was not able to achieve as low protein adsorption as the first approach. Key parameters to achieve superlow fouling surfaces were studied and discussed.     

High-capacity binding of proteins by poly(acrylic acid) brushes and their derivatives

Polymeric coatings with high protein-binding capacities are important for increasing the output of affinity-based protein purification and decreasing the detection limits of antibody microarrays. This report describes the use of thick poly(acrylic acid) (PAA) brushes to immobilize as much as 80 monolayers of protein. The brushes were prepared using a recently developed procedure that allows polymerization of 100-nm-thick poly(tert-butyl acrylate) films from a surface in just 5 min along with hydrolysis of these films to PAA in 15 min. Covalent binding of bovine serum albumin (BSA) to PAA brushes that were activated using standard coupling agents, however, resulted in immobilization of less than two monolayers of BSA because of competitive hydrolysis of the esters in the activated film. In contrast, derivatization of PAA with nitrilotriacetate (NTA)-Cu2+ complexes yielded films capable of binding many monolayers of protein via metal-ion affinity interactions. For example, derivatization of 55-nm-thick PAA films with NTA-Cu2+ allowed immobilization of about 15 monolayers (5.8 microg/cm2 or 58 nm) of BSA. The binding capacity was even higher for myoglobin (7.7 microg/cm2) and anti-IgG (9.6 microg/cm2). Remarkably, electrostatic adsorption of lysozyme in 55-nm-thick, underivatized PAA resulted in as much as 80 monolayers (16.2 microg/cm2 or 162 nm) of adsorbed protein. Polymer synthesis, derivatization, and swelling, as well as BSA immobilization kinetics and thermodynamics were characterized using reflectance FT-IR spectroscopy, ellipsometry, and protein assays.     

Tunable blood compatibility of polysulfobetaine from controllable molecular-weight dependence of zwitterionic nonfouling nature in aqueous solution

This work describes a tunable blood compatibility of zwitterionic poly(sulfobetaine methacrylate) (polySBMA) polymers at a wide range of high molecular weights from 50 kDa to 300 kDa controlled with a similar polydispersity via homogeneous free-radical polymerization. The control of molecular weights of polySBMA highly regulates the zwitterionic nonfouling nature to resist the adsorption of plasma proteins, the coagulant of human plasma, and the hemolysis of red blood cells. In this study, the upper critical solution temperatures (UCSTs) and hydrodynamic size of prepared polymers are determined to illustrate the correlations between intermolecular zwitterionic associations and blood compatibility of polySBMA suspension in human blood. The polySBMA exhibited clear shifts of UCSTs in the stimuli-responsive control of solution pH and ionic strength, which were strongly associated with the molecular weights of the prepared polymers. Plasma-protein adsorption onto the polySBMA polymers from single-protein solutions and the complex medium of 100% human plasma were measured by dynamic light scattering to determine the nonfouling stability of polySBMA suspension. It was found that the nonfouling nature as well as hydration capability of polySBMA can be effectively controlled via regulated molecular weights of zwitterionic polymers. This work shows that the polySBMA polymer with an optimized molecular weight of about 135 kDa at physiologic temperature is presented high hydration capability to function the best nonfouling character of anticoagulant activity and antihemolytic activity in human blood. The excellent blood compatibility of zwitterionic polySBMA along with their stimuli-responsive phase behavior in aqueous solution suggests their potential for use in blood-contacting targeted delivery and diagnostic applications.     

溶菌酶蛋白在聚合物防污膜表面的吸附

采用分子动力学模拟方法比较了溶菌酶蛋白在两种典型聚合物防污材料聚乙二醇(PEG)和聚二甲基硅氧烷(PDMS)表面的吸附行为, 在微观上探讨了聚合物膜表面性质对蛋白质吸附的影响. 根据蛋白质与聚合物膜之间的相互作用、能量变化及表面水化层分子的动力学行为, 解释了PEG防污涂层相对于PDMS表面具有更佳防污效果的原因: (1) 相比PDMS涂层, 蛋白质与PEG涂层的结合能量较低, 使其结合更加疏松; (2) 蛋白质吸附到材料表面要克服表面水化层分子引起的能障, PEG表面与水分子之间结合紧密, 结合水难于脱附, 造成蛋白质在其表面的吸附需要克服更高的能量, 不利于蛋白质的吸附.