Dual-functional poly(2-methyl-2-oxazoline)/poly(2-(dimethylamine)ethyl methacrylate)mixed brushes with switchable protein adsorption and antibacterial properties

Herein,binary mixed brushes consisting of poly(2-methyl-2-oxazoline)(PMOXA)and poly(2-(dimethylamine)ethyl methacrylate)(PDMAEMA)with different chain lengths were fabricated by successive grafting of NH_(2)-terminated PMOXA and SH-terminated PDMAEMA onto polydopamine-anchored substrates.The mixed-brush coating was characterized by variable-angle spectroscopic ellipsometry,X-ray photoelectron spectroscopy,Fourier transform infrared spectroscopy,zeta potential measurements,water contact angle,and atomic force microscopy.The mixed brushes showed tunable surface charge,wettability,and surface roughness,depending on the degree of PDMAEMA swelling under varying pH and ionic strength(Ⅰ).Then the adsorption behaviors of pepsin,bovine serum albumin(BSA),γ-globulin,and lysozyme,four very different proteins with regard to isoelectric point,on the mixed brushes coating were studied by using fluorescence microscopy and surface plasmon resonance.When the chain length of PDMAEMA was about twice as long as PMOXA,the mixed brushes not only had high adsorption capacity for pepsin,BSA,and y-globulin but also had a desorption efficiency of 86.9%,87.1%,and 93.5%,respectively.It is explained that electrostatic attraction between the protonated PDMAEMA and positively charged acidic proteins(pepsin and BSA,whose isoelectric points were below the pK_(a) of PDMAEMA)would drive the intensive adsorption(at pH 3,I=10^(-3)mol·L^(-1)for pepsin,and pH 5,I=10^(-5)mol·L^(-1)for BSA),while desorption was dominated by the hydrophilic PMOXA when PDMAEMA was shrinking(at pH 7,I=10^(-1)mol·L^(-1)for pepsin,and pH 9,I=10^(-1)mol·L^(-1)for BSA).Furthermore,the isoelectric precipitation led to the adsorption of neutral protein(γ-globulin,whose isoelectric point was near the pK_a of PDMAEMA)at pH 7,I=10^(-5)mol·L^(-1),while electrostatic repulsion and antifouling PMOXA triggered the desorption of y-globulin at pH 3,I-10^(-1)mol·L^(-1).However,alkaline protein(lysozyme,whose isoelectric point was higher than the pK_(a) of PDMAEMA)exhibited slight adsorption on PMOXA/PDMAEMA mixed brushes under test conditions,regardless of whether PMOXA or PDMAEMA occupied the outermost layer.The antibacterial property of the mixed brushes against Escherichia coli was investigated.PMOXA/PDMAEMA mixed brushes showed significant bactericidal activity at pH 3,I=10^(-3)mol·L^(-1),while the rinse of pH 9,I=10^(-1)mol·L^(-1)solution could remove most of the residual bacteria.This work not only enables controlled adsorption of proteins with different isoelectric points but also ensures that the surface of the coating is minimized from bacterial contamination.

Factors resisting protein adsorption on hydrophilic/hydrophobic self-assembled monolayers terminated with hydrophilic hydroxyl groups

The hydroxyl-terminated self-assembled monolayer(OH-SAM),as a surface resistant to protein adsorption,exhibits substantial potential in applications such as ship navigation and medical implants,and the appropriate strategies for designing anti-fouling surfaces are crucial.Here,we employ molecular dynamics simulations and alchemical free energy calculations to systematically analyze the factors influencing resistance to protein adsorption on the SAMs terminated with single or double OH groups at three packing densities(∑=2.0 nm^(-2),4.5 nm^(-2),and 6.5 nm^(-2)),respectively.For the first time,we observed that the compactness and order of interfacial water enhance its physical barrier effect,subsequently enhancing the resistance of SAM to protein adsorption.Notably,the spatial hindrance effect of SAM leads to the embedding of protein into SAM,resulting in a lack of resistance of SAM towards protein.Furthermore,the number of hydroxyl groups per unit area of double OH-terminated SAM at ∑=6.5 nm^(-2) is approximately 2 to 3 times that of single OH-terminated SAM at ∑=6.5 nm^(-2) and 4.5 nm^(-2),consequently yielding a weaker resistance of double OH-terminated SAM towards protein.Meanwhile,due to the structure of SAM itself,i.e.,the formation of a nearly perfect ice-like hydrogen bond structure,the SAM exhibits the weakest resistance towards protein.This study will complement and improve the mechanism of OH-SAM resistance to protein adsorption,especially the traditional barrier effect of interfacial water.

Plasma graft of poly(ethylene glycol) methyl ether methacrylate (PEGMA) on RGP lens surface for reducing protein adsorption

Poly（ethylene glycol） methyl ether methacrylate（PEGMA） was grafted on fluorosilicone acrylate rigid gas permissible contact lens surface by means of argon plasma induced polymerization to improve surface hydrophilicity and reduce protein adsorption.The surface properties were characterized by contact angle measurement,x-ray photoelectron spectroscopy（XPS） and atomic force microscopy respectively.The surface protein adsorption was evaluated by lysozyme solution immersion and XPS analysis.The results indicated that a thin layer of PEGMA was successfully grafted.The surface hydrophilicity was bettered and surface free energy increased.The lysozyme adsorption on the lens surface was reduced greatly.

Protein adsorption onto diethylaminoethyl dextran modified anion exchanger:Effect of ionic strength and column behavior

Our previous studies on bovine serum albumin （BSA） adsorption to diethylaminoethyl dextran （DEAE dextran, DexD, grafting-ligand） and DEAE （D, surface-ligand） modified Sepharose FF resins found that all the grafted resins （FF-DexD and FF-D-DexD） exhibited extremely fast uptake rate （effective diffusivity, De, De/Do 〉 1.4）, which was six times greater than the ungrafted resins （De/Do 〈 0.3）. In this work, the influence of ionic strength （IS） on 6 typical DEAE dextran-grafted resins was investigated. Bath adsorption equilibria and kinetics, breakthrough, and linear gradient elution experiments were conducted. Commercial DEAE Sepharose FF was used for comparison. It is found that protein adsorption capacities on DEAE dextran-FF resins and the commercial resin decreased with increasing IS, but DEAE dextran-FF resins exhibited much higher capacity sensitivity to salt concentration. Besides, steeper decrease of adsorption capacities could be obtained at higher graftingligand or surface-ligand density. It is worth noting that the facilitating role of surface-ligand to the ＂chain delivery＂ effect was weakened after adding salt, leading to the less improvement in uptake rate by increasing surface-ligand density at higher IS. Although the uptake rates of the DEAE dextran-FF resins increased first and then decreased with increasing fS, they kept the extremely high level of De values （De/Do 〉 1.1 ） at the their working/binding IS range. Moreover, the DEAE dextran-FF resin displayed much higher adsorption capacities and De values than commercial ungrafted resin in their working condition. Furthermore, the column results of DEAE dextran-FF resins presented higher dynamic binding capacities than and similar elution ISs with DEAE Sepharose FF to achieve similar （or even higher） recoveries suggest the excellent chromatographic column performance of the DEAE dextran-FF resins. Finally, both high recovery and purity of BSA and γ-globulin could be easily achieved using the typical DEAE dextran-FF column, FF-D60-DexD160, to separate their binary mixtures, by step gradient elution. The research has provided new insights into the practical application of the series of DEAE-dextran grafted resins in protein chromatography and proved their superiority.

Protein adsorption, cell viability and corrosion properties of Ti6Al4V alloy treated by plasma oxidation and anodic oxidation

The hardness,wettability,and electrochemical properties of Ti6Al4V alloy surfaces treated with anodic oxidation and plasma oxidation as well as the viabilities of the different cell lines on the obtained surfaces were investigated.The anodic oxidation was performed for 10 min under 100 V potential,and it resulted in a 0.95μm thick nanoporous anatase-TiO2 structure.On the other hand,plasma oxidation was carried out at 650℃ for 1 h and resulted in a dense rutile-TiO2 structure with a thickness of 1.2μm.While a hardness of HV0.025823 and roughness of^220 nm were obtained by plasma oxidation,those obtained by anodic oxidation were HV0.025512 and^130 nm,respectively.The anodic oxidation process created a more hydrophilic surface with a contact angle of 87.2°.Both oxidation processes produced similar properties in terms of corrosion behavior and showed better resistance than the as-received state in a certain range of potential.Moreover,the surface treatments led to no significant change in the protein adsorption levels,which indicates that the difference in viability between the osteoblast and fibroblast cells was not due to the difference in surface protein adsorption.Given all the factors,the surfaces obtained by anodic oxidation treatment revealed higher cell viability than those obtained by plasma oxidation(p=0.05).

Cellulose-based Polymeric Liquid Crystals as a Biomimetic Modifier for Suppressing Protein Adsorption

A novel biomimetic protein-resistant modifier based on cellulose-based polymeric liquid crystals was described（PLCs）. Two types of PLCs of propyl hydroxypropyl cellulose ester（PPC） and octyl hydroxypropyl cellulose ester（OPC） were prepared by esterification from hydroxypropyl cellulose, and then were mixed with polyvinyl chloride and polyurethane to obtain composite films by solution casting, respectively. The surface morphology of PLCs and their composite films were characterized by polarized optical microscopy（POM） and scanning electron microscopy（SEM）, suggesting the existence of microdomain separation with fingerprint texture in PLC composite films. Water contact angle measurement results indicated that hydrophilicity of PLC/polymer composite films was dependent on the type and content of PLC as well as the type of matrix due to their interaction. Using bovine serum albumin（BSA） as a model protein, protein adsorption results revealed that PLCs with protein-resistant property can obviously suppress protein adsorption on their composite films, probably due to their flexible LC state. Moreover, all PLCs and their composites exhibited non-toxicity by MTT assay, suggesting their safety for biomedical applications.

SURFACE MODIFICATION OF TITANIUM FILMS WITH SODIUM ION IMPLANTATION:SURFACE PROPERTIES AND PROTEIN ADSORPTION

Sodium implanted titanium films with different ion doses were characterized to correlate their ion implantation parameters. Native titanium films and ion implanted titanium films were characterized with combined techniques of X-ray photoelectron spectroscopy （XPS）, atomic force microscopy （AFM）, and light microscopy （LM）. The surface presented increased sodium concentration on treated titanium films with ion dose increasing, except for the group with the highest ion dose of 4×10^17ions/cm^2. XPS depth profiling displayed that sodium entered titanium film around 25-50nm depth depending on its implantation ion dose. AFM characterization showed that sodium ion implantation treatment changed the surface morphology from a relatively smooth titanium film to rough surfaces corresponding to different implantation doses. After sodium implantation, implanted titanium films presented big particles with island structure morphology. The surface morphology and particle growth displayed the corresponding trend. Fibrinogen adsorption on these titanium films was performed to correlate with the surface properties of treated titanium films. The results show that protein adsorption on ion-implanted samples with dose of 2×10^17 and 4×10^17 are statistically higher （p 〈0.01） than samples treated with dose of 5×10^16 and 1×10^17, as well as the control samples.

Fabrication and characterization of hierarchical porous Ni2+doped hydroxyapatite microspheres and their enhanced protein adsorption capacity

Hydroxyapatite(HAP)is a common bio-adsorbent,which performance depends heavily upon its morphology and microporous structure.In this study,a novel synthesis strategy was proposed for hierarchical porous HAP microspheres by a simple"one-pot"hydrothermal reaction.In the strategy,L-glutamic acid serves as soft template to modulate the morphology and inner crystalline of HAP.To evaluate the application potential,doping Ni^(2+) on hierarchical porous HAP microspheres gives metal chelated affinity adsorbents.The prepared adsorbents show a perfect spherical shape,particles size of 96.6μm,relatively specific surface area of 48.5 m^(2)·g^(-1) and hierarchical pores(mesopores:4 nm and macropores:53 nm).By the adsorption evaluation,it reveals that the Ni^(2+)-HAP adsorbents have high adsorption capacities of275.11 and 97.55 m^(2)·g^(-1) for hemoglobin and bovine serum albumin,respectively,which is comparable to other similar adsorbent.Therefore,this work provides a promising method for high-efficiency hydroxyapatite microspheres for proteins purification.

The Effect of Topologies and Refilling Short-chain PEG on Protein Adsorption

PEGylation is the gold standard for constructing protein resistance surfaces.Herein,grafting mPEG-SH and SH-PEG-SH with varied molecular weights(Mw=5K,10K,and 20K)on a gold chip,and the subsequent lysozyme adsorptions of the PEG layers are evaluated using quartzcrystal microbalance based on dissipation(QCM-D).The lysozyme resistance depends on the features of grafting density and chain conformation,i.e.,linear and looped conformation.However,long-chain PEG(Mw≥10K)is insufficient to form a dense layer to resist protein due to large steric hindrances.Short-chain PEG(Mw=1K)with linear and looped structures is used to refill onto the long-chain PEG layer to increase the grafting density of PEGs and improve protein resistance.The refilling process and the subsequent protein adsorption depend on conformation rather than the density of the long-chain PEG substrate.Notably,the long-chain PEG looped substrates significantly improve protein resistance,attributing to the high viscoelasticity of the looped substrate and an increase in grafting density after refilling.Thus,refilling short-chain PEG improves protein resistance and the substrate conformation-dependence gives insight into the impact of topology,providing new ideas for how to increase chain density and select suitable topology to resist protein adsorption and demonstrating a potential application in biomedical fields.

Effect of Pore-size of Mesoporous SBA-15 on Adsorption of Bovine Serum Albumin and Lysozyme Protein

In this paper,the effects of pore-size of SBA-15 on the adsorption kinetics and equilibrium of large protein molecules Bovine serum albumin(BSA)and lysozyme(LYS)have been investigated.The mesoporous molecular sieve SBA-15 with six different pore sizes were synthesized with P123 triblock copolymer as the template agent,and 1,3,5-trimethylbenzene(TMB)and isopropyl alcohol as the pore-expanding agent.The samples were characterized by N2 adsorption/desorption,Scanning Electron Microscopy(SEM),Transmission Electron Microscopy(TEM)and X-Ray Diffraction(XRD).It is found that BSA and LYS were adsorbed rapidly on SBA-15 materials with large pores.The BSA adsorption capacity of sieve with the pore diameter of 21.4 nm reached 500 mg·g-1 within 25 minutes.However,if the pore diameter was smaller than 14 nm,the BSA adsorption capacity of the sieve was only about 220 mg·g-1.The adsorption equilibrium data fits in the Langmuir model,where the coefficient of effective use of specific area of mesoporous molecular sieve was found to be 0.03,0.18,0.37 and 0.48,corresponding to the pore diameter of 10.1 nm,13.2 nm,15.4 nm and 21.4 nm,respectively.The equilibrium loading amount of LYS on SBA-15 materials with pore size of 15.4 nm could be up to 1000 mg·g-1.The coefficient of effective use of surface area of mesoporous molecular sieve with diameter of 3.9 nm,7.4 nm,10.1 nm,13.2 nm and 15.4 nm was 0.10,0.47,0.56,0.71 and 0.79,respectively.It is also noted that greater pore size of mesoporous molecular sieve would lead to a higher coefficient of effective use of surface area.

POLY(N-VINYLPYRROLIDONE)-MODIFIED SURFACES REPEL PLASMA PROTEIN ADSORPTION

The present work aimed to study the interaction between plasma proteins and PVP-modified surfaces under more complex protein conditions. In the competitive adsorption of fibrinogen （Fg） and human serum albumin （HSA）, the modified surfaces showed preferential adsorption of HSA. In 100% plasma, the amount of Fg adsorbed onto PVP-modified surfaces was as low as 10 ng/cm2, suggesting the excellent protein resistance properties of the modified surfaces. In addition, immunoblots of proteins eluted from the modified surfaces after plasma contact confirmed that PVP-modified surfaces can repel most plasma proteins, especially proteins that lalav important roles in the nrocess of blood coagulation.

Advanced protein adsorption properties of a novel silicate-based bioceramic: A proteomic analysis

Silicate bioceramics have been shown to possess excellent cytocompatibility and osteogenic activity,but the exact mechanism is still unclear.Protein adsorption is the first event taking place at the biomaterial-tissue interface,which is vital to the subsequent cellular behavior and further influence the biomaterial-tissue interaction.In this work,the protein adsorption behavior of a novel CPS bioceramic was evaluated using the proteomics technology.The results showed that CPS adsorbed more amount and types of serum proteins than HA.FN1 and IGF1 proteins selected from proteomics results were validated by Western-blot experiment.Pathway analysis also revealed mechanistic insights how these absorbed proteins by CPS help mediate cell adhesion and promotes osteogenic activity.Firstly,the dramatically enhanced adsorption of FN1 could greatly promote cell adhesion and growth.Secondly,IGF1 was uniquely adsorbed on CPS bioceramic and IGF1 could activate Rap1 signaling pathway to promote cell adhesion.Thirdly,the increased adsorption of FN1,IGF1 and COL1A2 proteins on CPS explains its better ability on bone regeneration than HA.Fourthly,the increased adsorption of IGF1,CHAD,COL2A1 and THBS4 proteins on CPS explains its ability on cartilage formation.Lastly,the increased adsorption of immunological related proteins on CPS may also play a positive role in bone regeneration.In addition,CPS had a much better cell adhesion ability than HA,proving that more adsorbed proteins really had a positive effect on cell behavior.The more adsorbed proteins on CPS than HA might indicated a better bone regeneration rate at early stage of implantation.

Immunocamouflage of latex surfaces by grafted methoxypoly(ethylene glycol)(mPEG):Proteomic analysis of plasma protein adsorption

Grafting of methoxypoly(ethylene glycol)(mPEG) to cells and biomaterials is a promising non-pharmacological immunomodulation technology.However,due to the labile nature of cells,surface-plasma interactions are poorly understood;hence,a latex bead model was studied.PEGylation of beads resulted in a density and molecular weight dependent decrease in total adsorbed protein with a net reduction from(159.9±6.4) ng cm-2 on bare latex to(18.4±0.8) and(52.3±5.3) ng cm-2 on PEGylated beads(1 mmol L-1 of 2 or 20 kD SCmPEG,respectively).SDS-PAGE and iTRAQ-MS analysis revealed differential compositions of the adsorbed protein layer on the PEGylated latex with a significant reduction in the compositional abundance of proteins involved in immune system activation.Thus,the biological efficacy of immunocamouflaged cells and materials is mediated by both biophysical obfuscation of antigens and reduced surface-macromolecule interactions.

Recent advances towards single biomolecule level understanding of protein adsorption phenomena unique to nanoscale polymer surfaces with chemical variations

Protein adsorption onto polymer surfaces is a very complex and ubiquitous phenomenon whose integrated process impacts essential applications in our daily lives such as food packaging materials,health devices,diagnostic tools,and medical products.Increasingly,novel polymer materials with greater chemical intricacy and reduced dimensionality are used for various applications involving adsorbed proteins on their surfaces.Hence,the nature of protein-surface interactions to consider is becoming much more complicated than before.A large body of literature exists for protein adsorption.However,most of these investigations have focused on collectively measured,ensemble-averaged protein behaviors that occur on macroscale and chemically unvarying polymer surfaces instead of direct measurements at the single protein or sub-protein level.In addition,interrogations of protein-polymer adsorption boundaries in these studies were typically carried out by indirect methods,whose insights may not be suitably applied for explaining individual protein adsorption processes occurring onto nanostructured,chemically varying polymer surfaces.Therefore,an important gap in our knowledge still exists that needs to be systematically addressed via direct measurement means at the single protein and sub-protein level.Such efforts will require multifaceted experimental and theoretical approaches that can probe multilength scales of protein adsorption,while encompassing both single proteins and their collective ensemble behaviors at the length scale spanning from the nanoscopic all the way to the macroscopic scale.In this review,key research achievements in nanoscale protein adsorption to date will be summarized.Specifically,protein adsorption studies involving polymer surfaces with their defining feature dimensions and associated chemical partitions comparable to the size of individual proteins will be discussed in detail.In this regard,recent works bridging the crucial knowledge gap in protein adsorption will be highlighted.New findings of intriguing protein surface assembly behaviors and adsorption kinetics unique to nanoscale polymer templates will be covered.Single protein and sub-protein level approaches to reveal unique nanoscale protein-polymer surface interactions and protein surface assembly characteristics will be also emphasized.Potential advantages of these research endeavors in laying out fundamentally guided design principles for practical product development will then be discussed.Lastly,important research areas still needed to further narrow the knowledge gap in nanoscale protein adsorption will be identified.

Controllable Protein Adsorption and Bacterial Adhesion on Polypyrrole Nanocone Arrays

In this research, polypyrrole nanocone arrays doped with β-Naphthalene sulphonic acid （PPy-NSA） were built. This film was expected to control protein adsorption and bacterial adhesion by potential-induced reversibly redox. The scanning Kelvin probe microscopy （SKPM） and surface contact angles （SCA） tests suggested that the surface potential and wettability of PPy-NSA nanocone arrays could be controlled by simply controlling its redox property via applying potential. The controllable surface potential and wettability in return controlled the adsorption of protein and adhesion of bacteria. The proposed material might find application in the preparation of smart biomaterial surfaces that can regulate proteins and bacterial adhesion by a simple potential switching.

Construction of Nanophase Novel Coatings-Based Titanium for the Enhancement of Protein Adsorption

In the recent years,biological nanostructures coatings have been incorporated into orthopedic and dental implants in order to accelerate osseointegration and reducing surgical restrictions.In the present work,chemical etching,anodization and metal doping surface modification methods were integrated in one strategy to fabricate innovative titanium surfaces denominated by titanium nanoporous,anodized titanium nanoporous,silver-anodized titanium nanoporous and gold-anodized titanium nanoporous.The stability properties of nanostructures-coated surfaces were elucidated using electrochemical impedance spectroscopy（EIS） after 7 days of immersion in simulated biological fluids.Morphology and chemical compositions of new surfaces were characterized by scanning electron microscope and energy-dispersive X-ray analysis.The EIS results and data fitting to the electrical equivalent circuit model demonstrated the influence of adsorption of bovine serum albumin on new surfaces as a function of protein concentration.Adsorption process was described by the very well-known model of the Langmuir adsorption isotherm.The thermodynamic parameter DGADS（-50 to 59 kJ mol^（-1）） is calculated,which supports the instantaneous adsorption of protein from biological fluids to new surfaces and refers to their good biocompatibility.Ultimately,this study explores new surface strategy to gain new implants as a means of improving clinical outcomes of patients undergoing orthopedic surgery.

PROTEIN ADSORPTION AND CELL ADHESION ON RGD-FUNCTIONALIZED SILICON SUBSTRATE SURFACES

A method was developed to modify silicon surfaces with good protein resistance and specific cell attachment. A silicon surface was initially deposited using a block copolymer of N-vinylpyrrolidone （NVP） and 2-hydroxyethyl methacrylate （HEMA） （PVP-b-PHEMA） film through surface-initiated atom transfer radical polymerization and then further immobilized using a short arginine-glycine-aspartate （RGD） peptide. Our results demonstrate that the RGD-modified surfaces （Si-RGD） can suppress non-specific adsorption of proteins and induce the adhesion of L929 cells. The Si-RGD surface exhibited higher cell proliferation rates than the unmodified silicon surface. This research established a simple method for the fabrication of dual-functional silicon surface that combines antifouling and cell attachment promotion.

Analysis of statistical thermodynamic model for binary protein adsorption equilibria on cation exchange adsorbent

A study of nonlinear competitive adsorption equilibria of proteins is of fundamental importance in understanding the behavior of preparative chromatographic separation.This work describes the nonlinear binary protein adsorption equilibria on ion exchangers by the statistical thermodynamic(ST)model.The single-component and binary protein adsorption isotherms of bovine hemoglobin(Hb)and bovine serum albumin(BSA)on SP Sepharose FF were determined by batch adsorption experiments in 0.05 mol/L sodium acetate buffer at three pH values(4.5,5.0 and 5.5)and three NaCl concentrations(0.05,0.10 and 0.15 mol/L)at pH 5.0.The ST model was found to depict the effects of pH and ionic strength on the single-component equilibria well,with model parameters depending on the pH and ionic strength.Moreover,the ST model gave acceptable fitting to the binary adsorption data with the fitted single-component model parameters,leading to the estimation of the binary ST model parameter.The effects of pH and ionic strength on the model parameters are reasonably interpreted by the electrostatic and thermodynamic theories.Results demonstrate the availability of the ST model for describing nonlinear competitive protein adsorption equilibria in the presence of two proteins.

Reversible Protein Adsorption on PMOXA/PAA Based Coatings:Role of PAA

In this study we report design of stimuli-resP0nsive coating based on poly（2-methyl-2-oxazoline-random-glycidyl methacrylate） （PMOXA-r-GMA） comb copolymer and poly（acrylic acid）-block-poly（glycidyl methacrylate） （PAA-b-PGMA） block copolymers and scrutinize its ability to control protein adsorption. Firstly, PMOXA/PAA based coatings were prepared by simply spin coating the mixture of PMOXA-r-GMA and PAA-b-PGMA copolymer solutions onto silicon substrates followed by annealing at 110℃. Then coatings were rigorously characterized by X-ray photoelectron spectroscopy （XPS）, the static water contact angle （WCA） test, ellipsometry and atomic force microscopy （AFM）. After that, the relationship of switchable behavior of PMOXA/PAA based coatings with PAA content and chain length was investigated through the change of thickness and WCA upon pH and ionic strength （I） trigger, which indicated that the change in thickness and WCA was triggered when PAA contents were increased as well as by increasing chain length of PAA in PMOXA/PAA based coatings. Finally, real-time adsorption/desorption of lysozyme （Lyso） on PMOXA/PAA based coatings was monitored using quartz crystal microbalance with dissipation monitoring （QCM-D）. The results showed that the Lyso adsorption amount was increased upon increasing chain length and contents of PAA in PMOXA/PAA based coatings. The adsorbed Lyso was then efficiently desorbed by changing pH and I of medium with the maximum desorption （〉 90% desorption percentage） observed for the suitable ratio of PMOXA and PAA while chain length of PAA was kept longer than that of PMOXA. Furthermore, the prepared coatings were found to repeatedly adsorb and desorb Lyso for four successive cycles of adsorption/desorption, which confirmed the stability of prepared coatings.