Dissipative Particle Dynamics Simulations Research Articles

Formation and snake-eating like solubilization mechanisms of rhamnolipid vesicles for oil components and amino acids

Rhamnolipid vesicles hold significant potential across a wide range of applications, yet their formation mechanisms and selective solubilization of organic molecules remain elusive. Employing dissipative particle dynamics (DPD) simulations, this study delves deeply into these aspects, uncovering a stepwise formation pathway from dispersed monomers to complex multi-layer vesicle structures. The fusion and growth of three-layer structures were identified as crucial steps in the development of stacked vesicles. Notably, double-chain rhamnolipids (Rh-C10-C10) exhibited enhanced stability in self-assembled structures compared to their single-chain counterparts (Rh-C10). Through a detailed analysis of parameters such as relative concentration distribution, radial distribution function, and density fields, the solubilization process of rhamnolipid vesicles was found to resemble a “snake-eating” mechanism. We also analyzed the solubilization sites, amounts, and vesicle sizes, elucidating the selective solubilization mechanisms of rhamnolipids for representative polar and non-polar compounds in crude oil, anisole and 1-hexene. The selectivity of rhamnolipid vesicles in solubilizing organic molecules was primarily influenced by polar attraction and steric hindrance, which together determined their solubilization sites within the vesicles. Additionally, the solubilization behavior and properties of five types of amino acids within rhamnolipid vesicles were explored, demonstrating analogous solubilization patterns that correlated with amino acid polarity. These results provide a foundation for optimizing the application of rhamnolipid vesicles, paving the way for potential advancements in drug delivery, environmental remediation, and oil recovery processes.

Interactions of hydrophobically associating polymers with anionic surfactant sodium dodecylbenzene sulfonate: Experiments and simulations

Herein, the interaction of the hydrophobically associating polymer HP-1 with the anionic surfactant sodium dodecylbenzene sulfonate (SDS) was investigated using solution viscosity by Brookfield viscometer, rheology including steady shear rheology and dynamic frequency sweep rheology, ambient scanning electron microscopy, and fluorescence measurements and then simulated and analyzed using dissipative particle dynamics simulations (DPD). The results showed that as SDS concentration increased, the solution viscosity of the HP-1/SDS system first declined, then increased, reached a peak, and then decreased again before gradually leveling off. The rheology and microscopic morphology of the system exhibited similar patterns of change. The system’s solution shear rheology and viscoelasticity decreased with increasing SDS concentration, then increased and ultimately decreased, and the system’s reticulation structure changed from loose to tight and then again to loose, according to the law of composite viscosity. Moreover, the ratio of the emission peak intensities of the monomer fluorescence spectra of pyrene molecules in solution at 372 and 383 nm (I3/I1) first decreased, then increased, and finally stabilized. This implies that the above phenomenon is associated with the change in the number of HP-1’s hydrophobic interaction. Thus, SDS affects both the binding efficiency and number of binding groups of HP-1, resulting in a change in the properties of the solution. Finally, DPD simulations were performed to study the interaction between SDS and HP-1, confirming the experimental data-derived supposition. Upon the addition of SDS, it began to interact with HP-1 hydrophobic groups until all of the hydrophobic groups were coated with SDS, resulting in coiling of the HP-1 polymer chains. Meanwhile, SDS molecules adsorbed onto the polymer chain and aggregated with each other to form micelles, altering the properties of the solution.

Coupling simulation and experimental study of drug loading and releasing behaviors in phytol-based micelles

Phytol, as a potential drug-carrier, can regulate the cellular reactive oxygen species (ROS) levels in a dose-dependent manner, decreasing them at lower doses and increasing them at higher doses. In this study, we developed phytol-based micelles composed of phytol, PEG, and OE, which can clearly enhance drug delivery efficacy and simultaneously protect normal cells. Drug-loading and -releasing mechanisms of phytol-based micelles were investigated combined with dissipative particle dynamics (DPD) simulations and experimental. The simulation results indicate that Ph4EO22Ph4 exhibits the most desirable properties for forming phytol-based micelles compared with other phytol-based polymers we designed. We found that co-loading (purpurin 18 a) P18 and paclitaxel (PTX) within the Ph4EO22Ph4 micelle not only enhances the encapsulation efficiency (EE) of P18 (P18’s EE rised from 85.16 % to 91.17 %) but also optimizes the overall micellar structure, exhibiting excellent DL capability along with sustained release (75.2 % PTX releasing after 72 h) performance under acidic conditions. The release mechanism varies with the loaded drugs, in which PTX is released in its molecular form while P18 is released through P18/Ph4 particles. In the latter case, Ph4 within the particles significantly facilitates cellular uptake of P18 drugs by 4T1 cells, thereby enhancing therapeutic efficacy. Interestingly, Ph4EO22Ph4 exhibited significantly higher cytotoxicity towards 4T1 cells compared to HC11. Therefore, the phytol-based micelles incorporating a concentration-dependent hydrophobic block and a steric effect-driven hydrophilic block composed of PEG demonstrated enhanced efficacy and reduced toxicity. The present study presents a novel phytol-based micelle system incorporating DPD simulation and experimental validation, which effectively addresses the challenges encountered by P18 and PTX. Moreover, it comprehensively investigates drug loading and releasing behaviors in phytol-based micelles from various perspectives, thereby offering valuable insights for the design of alternative drug delivery systems.

Mineralized Nanofiber Substrates Enabling High-Performance Dually Charged Nanofiltration Membranes with Enhanced Permeability.

Nanofiltration membranes (NFMs) with superior permeability and high rejection of both divalent anions and cations are highly desirable to meet the increasing separation demands of complex systems. Herein, we propose a three-in-one strategy to develop a state-of-the-art dually charged thin-film composite (TFC) nanofiltration membrane consisting of a positively charged electrospun nanofiber substrate (NFS) with surface mineralization and a negatively charged polyamide (PA) selective layer prepared by interfacial polymerization (IP). The highly hydrophilic mineralized nanofiber substrate not only effectively reduces the thickness of the PA selective layer but also crumples its structures by the abundant zirconia nanoparticles on the substrate surface, resulting in excellent water flux (15.0 L m-2 h-1 bar-1) for the TFC NFMs. The relationship between the thickness of the selective layer and substrate is further investigated using dissipative particle dynamics (DPD) simulations. Meanwhile, the dually charged NFM exhibits relatively high rejection for both anions (97.1% for Na2SO4 and 97.9% for MgSO4) and cations (87.9% for MgCl2) in aqueous solutions compared with single-charged membranes, which is attributed to the dual-repulsion effect of the selective layer and the substrate surface bearing opposite charges. Moreover, the prepared NFMs exhibit good stability and excellent antifouling performance. This work may pave the way for the development of highly efficient nanofiltration membranes for the practical separation of comprehensively charged solutes.

Self-Assembly of Colloidal Dumbbell Isomers and Plasmonic Properties for Optical Metamaterials.

In this study, we explore the self-assembly of various colloidal symmetric dumbbell (DB) isomers, including dipole Janus, cis-Janus, trans-Janus, apolar-inward and polar-inward perpendicular Janus, and alternating perpendicular Janus DBs. Using dissipative particle dynamics (DPD) simulations under conditions mimicking experimental setups, we investigate cluster formation driven by emulsion droplet evaporation. Our findings reveal a diverse set of cluster structures, which are in good agreement with experimental and simulation results reported in the literature while also predicting the formation of novel cluster configurations. These structures, characterized by well-defined and predictable patterns, are potentially applicable to creating colloidal molecules and crystals. Furthermore, we examine the dynamics of cluster formation to gain insight into the mechanisms guiding the self-assembly of these diverse colloidal DBs. The study highlights the impact of particle isomerism on the resulting assembly structures. We further select a set of typical nanoclusters obtained, including a tetrahedral cluster, which is the simplest, to study its plasmonic properties. Our findings indicate that increasing the nanoparticle (NP) radius or decreasing the gap between NPs leads to a red shift in the plasmonic resonance wavelength and enhances the resonance strength. We identify critical parameter regions where the electric-dipole and magnetic-dipole resonances can be engineered to achieve negative dielectric permittivity and magnetic permeability, which are essential for developing negative-index metamaterials.

Enhancing the Encapsulation Performances of Liposomes for Amphiphilic Copolymers by Computer Simulations.

Liposomes, which encapsulate drugs into an inner aqueous core and demonstrate high drug-loading capacity, have attracted considerable interest in the field of drug delivery. Herein, the encapsulation processes for amphiphilic copolymers within liposomes have been investigated systematically to enhance the encapsulation capacity and optimize the structures using dissipative particle dynamics simulations. The results indicate that the physicochemical properties of lipids, receptors, and amphiphilic copolymers collectively determine the encapsulation behaviors of liposomes. Adjusting the hydrophobic interaction between hydrophobic tails of lipids (receptors) and hydrophobic blocks of copolymers, along with modulating the specific interaction between ligands and the functional head groups of receptors, can lead to various encapsulation capacities. Significantly, a medium hydrophobic interaction strength or a strong specific interaction is conducive to achieving a higher degree of encapsulation for amphiphilic copolymers. Furthermore, varying the key parameters, such as the hydrophobic interaction, the specific interaction, as well as the concentrations of lipids and receptors, can induce seven typical aggregate structures: heterogeneous, fully encapsulated, partially encapsulated, saturated-encapsulated, unsaturated-encapsulated, multilamellar, and column-like structures. The final phase diagrams are also constructed to provide a guideline for designing various structures of liposomes encapsulated with amphiphilic copolymers. These results significantly contribute to the illumination of strategies for the rational construction of the self-assembly system that facilitates the efficient encapsulation of amphiphilic copolymers within the inner aqueous core of liposomes, thereby providing valuable insights into the optimal design of liposome carriers for future biomedical applications.

Dissipative Particle Dynamics Using Conductor-Like Screening Model for Real Solvents-Based Interaction Parameters for Classical Simulations of Dibenzothiophene Adsorption on Molybdenum Disulfide Nanoparticles.

The previous step before the catalytic activity of MoS2 nanoparticles for the hydrodesulfurization of dibenzothiophene (DBT), i.e., the DBT adsorption, is studied through dissipative-particle-dynamics (DPD) simulations. Density-functional-theory (DFT) calculations reveal that although DBT is chemisorbed, and, therefore, there is an intermolecular electronic exchange leading to the weakening of the DBT's C-S bonds, the formed individual linking bonds among DBT and MoS2 are noncovalent, fact that allows the application of DPD in order to at least qualitatively estimate the fraction of the content of DBT molecules within an oleic solvent that can be adsorbed by the MoS2 nanoparticles. With the sake of getting realistic insights, we calculated the classical-DPD interaction parameters through the quantum-statistical approach conductor-like screening model for real solvents. A comparison between DFT calculations and the DPD simulations reveals that the quantum spontaneous attraction of DBT by MoS2 nanoparticles begins at the distance where the DBT's volumetric density in the neighborhood of a MoS2 nanoparticle is maximum, as well as that the alkylic chain of the oleic solvent has an important influence on the performance of the catalyst since the chain length increases the probability that DBT will find MoS2. These results suggest the combined DFT and DPD study can be useful for the design of HDS catalysts.

Solubilization of thymol based on alkyl polyglucoside microemulsions

Thymol, a widely utilized essential oil compound, boasts diverse applications as a flavoring agent, antibacterial agent, and preservative due to its potent antibacterial, antiviral, and preservative properties. However, its solid crystal form and limited water solubility pose significant obstacles to practical implementation. So, this study aimed to enhance thymol’s water solubility and broaden its applications by formulating an oil-in-water (O/W) microemulsion using the green surfactant alkyl polyglycoside (APG). To assess the solubilization capacity of different formulations, a pseudoternary phase diagram was constructed, comparing the area ratio of the single-phase region, and the optimal formulation ratios were determined: a 1:2 mass ratio of thymol to oleic acid for the mixed oil phase and a 3:1 mass ratio of APG0810 to ethanol for the surfactant phase. Achieving a 1:9 mass ratio of oil phase to surfactant phase, with a water content exceeding 70 %, yielded an infinitely dilutable O/W microemulsion. Particle size measurements confirmed the microemulsion’s long-term stability across various temperatures. Investigation of thymol’s solubilization within the microemulsion utilized fluorescence spectroscopy and 1H NMR spectroscopy, revealing preferential dissolution within the palisade layer composed of APG carbon chains. Molecular dynamics simulations and dissipative particle dynamics simulations were employed to calculate the interfacial formation energy of different APG in the ternary system, providing insights into the relationship between molecular structure and interfacial activity. In conclusion, this study presents an APG-based O/W microemulsion with excellent stability as a means to enhance thymol’s solubility, enabling its wider application in various fields.

Capturing the mechanosensitivity of cell proliferation in models of epithelium

Despite the primary role of cell proliferation in tissue development and homeostatic maintenance, the interplay between cell density, cell mechanoresponse, and cell growth and division is not yet understood. In this article, we address this issue by reporting on an experimental investigation of cell proliferation on all time- and length-scales of the development of a model tissue, grown on collagen-coated glass or deformable substrates. Through extensive data analysis, we demonstrate the relation between mechanoresponse and probability for cell division, as a function of the local cell density. Motivated by these results, we construct a minimal model of cell division in tissue environment that can recover the data. By parameterizing the growth and the dividing phases of the cell cycle, and introducing such a proliferation model in dissipative particle dynamics simulations, we recover the mechanoresponsive, time-dependent density profiles in 2D tissues growing to macroscopic scales. The importance of separating the cell population into growing and dividing cells, each characterized by a particular time scale, is further emphasized by calculations of density profiles based on adapted Fisher-Kolmogorov equations. Together, these results show that the mechanoresponse on the level of a constitutive cell and its proliferation results in a matrix-sensitive active pressure. The latter evokes massive cooperative displacement of cells in the invading tissue and is a key factor for developing large-scale structures in the steady state.

Simulation and experimental investigation of electret polypropylene fiber preparation via centrifugal melt electrospinning for enhanced air filtration

Rapid urbanization and industrialization have led to severe air pollution, enabling bacteria and viruses to become suspended in aerosol particles, which can be inhaled and pose a significant threat to human health. Electrostatic filtration offers a solution to enhance filtration efficiency without increasing resistance. However, traditional electret methods involve the usage of toxic solvent evaporation, and electret filter materials like polypropylene (PP) often suffer from rapid charge dissipation. In this study, we combined centrifugal melt electrospinning with Dissipative Particle Dynamics simulations to achieve continuous electret production and investigate the influence of experimental conditions and polymer additives on the charge-trapping capability of PP fibers. The results show that centrifugal melt electrospinning significantly enhances the charge storage capacity of PP fibers. The α crystal form of PP enhances electret performance by generating more effective charge traps, and experimental parameters influence electret performance by altering crystal forms. Additives effectively promote charge stability, resulting in stable voltages up to 11.09 kV with 1.5 wt% electret additive. Moreover, our study elucidates the correlation between crystal structure and electret performance, providing valuable data for regulating electret PP fibers.

Molecular modelling of active oil droplet propulsion: Insights from dissipative particle dynamics simulation

This study employed dissipative particle dynamics (DPD) simulations to investigate the self-propelled motion of oil droplets in water–oil–surfactant systems. It is the first attempt to replicate self-propulsion models of oil droplets at the molecular level, contrasting previous simulations focused on Brownian motion and hydrodynamic behaviour of colloidal particles. The DPD model reproduced droplet propulsion and visualised internal Marangoni flow, showing that larger droplet radii and greater interfacial tension differences increase propulsion speeds. Additionally, surfactants with stronger oil–oil repulsion enhanced propulsion speed, suggesting that surfactant-induced local structures are crucial for the self-propulsion mechanism.

Dissipative Particle Dynamics Study on Interfacial Properties of Ternary H-Shaped Copolymer–Homopolymer Blends

Dissipative particle dynamics (DPD) simulations is used to study the effect of Am/2BmAm/2 and H-shaped (Am/4)2Bm(Am/4)2 block copolymers on the interfacial properties of ternary blends. Our simulations show the following: (i) The capacity of block copolymers to diminish interfacial tension is closely linked to their compositions. With identical molecular weights and concentrations, H-shaped block copolymers outperform triblock copolymers in mitigating interfacial tension. (ii) The interfacial tension within the blends correlates positively with the escalation in H-shaped block copolymer molecular weight. This correlation suggests that H-shaped block copolymers featuring a low molecular weight demonstrate superior efficacy as compatibilizers when contrasted with those possessing a high molecular weight. (iii) Enhancing the concentration of H-shaped block copolymers fosters their accumulation at the interface, leading to a reduction in correlations between immiscible homopolymers and a consequent decrease in interfacial tension. (iv) As the length of the homopolymer chains increases, there is a concurrent elevation in interfacial tension, suggesting that H-shaped block copolymers perform more effectively as compatibilizers in blends characterized by shorter homopolymer chain lengths. These findings elucidate the associations between the efficacy of H-shaped block copolymer compatibilizers and their specific molecular characteristics.

Influence of nanoparticles on cylinder-forming linear triblock copolymers

We investigated the influences of nanoparticles on the cylinder-forming triblock copolymers by dissipative particle dynamics (DPD) simulations. We focused on the various aspect ratio and concentrations of the nanoparticles (NPs) with neutral surfaces, where three cases, the nanosphere, nano-ellipsoid and nanorod, were considered. The results indicated that the NPs tend to aggregate in interfaces between the blocks at low NP concentration, but penetrate the cylinder domains when the NP concentration is increased. The shape of NPs has obvious effect on the deforming of cylinder domains, where the NPs with larger aspect ratio are easier to deform the cylinder domains and in turn, their orientations are strongly affected by the polymer chains. These observations provide a deeper understanding of potential applications for microstructures based on complex block copolymers and nanoparticle mixtures.

Segregation kinetics of miktoarm star polymers: A dissipative particle dynamics study.

We study the phase separation kinetics of miktoarm star polymer (MSP) melts/blends with diverse architectures using dissipative particle dynamics simulation. Our study focuses on symmetric and asymmetric miktoarm star polymer (SMSP/AMSP) mixtures based on arm composition and number. For a fixed MSP chain size, the characteristic microphase-separated domains initially show diffusive growth with a growth exponent ϕ∼1/3 for both melts that gradually crossover to saturation at late times. The simulation results demonstrate that the evolution morphology of SMSP melt exhibits perfect dynamic scaling with varying arm numbers; the timescale follows a power-law decay with an exponent θ≃1 as the number of arms increases. The structural constraints on AMSP melts cause the domain growth rate to decrease as the number of one type of arms increases while their length remains fixed. This increase in the number of arms for AMSP corresponds to increased off-criticality. The saturation length in AMSP follows a power-law increase with an exponent λ≃2/3 as off-criticality decreases. Additionally, macrophase separation kinetics in SMSP/AMSP blends show a transition from viscous (ϕ∼1) to inertial (ϕ∼2/3) hydrodynamic growth regimes at late times; this exhibits the same dynamical universality class as linear polymer blends, with slight deviations at early stages.

Buffer Screening of Protein Formulations Using a Coarse-Grained Protocol Based on Medicinal Chemistry Interactions.

In drug and vaccine development, the designed protein formulation should be highly stable against the temperature, pH, buffer, excipients, and other environmental settings. Similarly, in a sensing unit, one needs to know how strongly two biomolecules bind to guide the design of the biorecognition unit accordingly. Typically, the community performs a series of experiments to thoroughly examine the parameter space, the so-called design-of-experiment (DoE) method, to identify the optimal formulation conditions. Unfortunately, extensive physical testing entails high costs, repeatability issues, and a lack of in-depth knowledge of the underlying mechanisms that affect the final outcome. To address these challenges, we developed a physics-based simulation protocol for buffer screening of protein formulations. We are introducing a coarse-grained molecular simulation protocol that consists of six different interactions. The so-called medicinal chemistry interactions (electrostatics, hydrophobicity, hydrogen bonding propensity, disulfide bonding, and water-water) are based on the physical nature of the protein's amino acid and the partitioning/polarity of any other chemical constituent. The protocol is applied in immunoglobulin-based monoclonal antibodies. We have analyzed the protein behavior as a function of acidity (pH) to discover the isoelectric point by solving the Poisson-Boltzmann equation in a mesoscale grid. To identify the conditions under which the protein oligomerizes in a given buffer, pH, temperature, and ionic strength, we are performing dissipative particle dynamics (DPD) simulations. The protocol allows researchers to reach the high time/space scales required to study protein formulations in their full complexity. Combined with the disruptive protein folding artificial intelligence (AI) algorithms that have been recently developed, the protocol creates a powerful digital framework for cultivating advanced pharmaceutical and biological applications.

The Formation Mechanism of Carbonized Polymer Dots: Crosslinking-Induced Nucleation and Carbonization.

Carbon dots (CDs), as a kind of zero-dimensional nanomaterials, have been widely synthesized by bottom-up methods from various precursors. However, the formation mechanism is still unclear and controversial, which also brings difficulty to the regulation of structures and properties. Only some tentative formation processes were postulated by analyzing the products obtained at different reaction times and temperatures. Here, the effect of crosslinking on the formation of carbonized polymer dots (CPDs) is explored. Crosslinking-induced nucleation and carbonization (CINC) is proposed as the driving force for the formation of CPDs. Under hydrothermal synthesis, the precursors are initiated to polymerize and crosslink. The crosslinking brings higher hydrophobicity to generate the hydrophilic/hydrophobic microphase separation, which promotes dehydration and carbonization resulting in the formation of CPDs. Based on the principle of CINC, the influence factors of size are also revealed. Moreover, the dissipative particle dynamics (DPD) simulation is employed to support this formation mechanism. This concept of CINC will bring light to the formation process of CPDs, as well as facilitate the regulation of CPDs' size and photoluminescence.

The Formation Mechanism of Carbonized Polymer Dots: Crosslinking‐Induced Nucleation and Carbonization

AbstractCarbon dots (CDs), as a kind of zero‐dimensional nanomaterials, have been widely synthesized by bottom‐up methods from various precursors. However, the formation mechanism is still unclear and controversial, which also brings difficulty to the regulation of structures and properties. Only some tentative formation processes were postulated by analyzing the products obtained at different reaction times and temperatures. Here, the effect of crosslinking on the formation of carbonized polymer dots (CPDs) is explored. Crosslinking‐induced nucleation and carbonization (CINC) is proposed as the driving force for the formation of CPDs. Under hydrothermal synthesis, the precursors are initiated to polymerize and crosslink. The crosslinking brings higher hydrophobicity to generate the hydrophilic/hydrophobic microphase separation, which promotes dehydration and carbonization resulting in the formation of CPDs. Based on the principle of CINC, the influence factors of size are also revealed. Moreover, the dissipative particle dynamics (DPD) simulation is employed to support this formation mechanism. This concept of CINC will bring light to the formation process of CPDs, as well as facilitate the regulation of CPDs’ size and photoluminescence.

Dissipative Particle Dynamics of Nano-Alumina Agglomeration in UV-Curable Inks.

Ultraviolet (UV) ink is a primary type of ink used in additive manufacturing with 3D inkjet printing. However, ink aggregation presents a challenge in nano-inkjet printing, affecting the stability and quality of the printing fluid and potentially leading to the clogging of nanometer-sized nozzles. This paper utilizes a Dissipative Particle Dynamics (DPD) simulation to investigate the aggregation behavior of alumina in a blend of 1,6-Hexanediol diacrylate (HDDA) and Trimethylolpropane triacrylate (TMPTA). By analyzing the effects of solid content, polymer component ratios, and dispersant concentration on alumina aggregation, the optimal ink formulation was identified. Compared to traditional experimental methods, DPD simulations not only reduce experimental costs and time but also reveal particle aggregation mechanisms that are difficult to explore through experimental methods, providing a crucial theoretical basis for optimizing ink formulations. This study demonstrates that alumina ceramic ink achieves optimal performance with a solid content of 20%, an HDDA-to-TMPTA ratio of 4:1, and 9% oleic acid as a dispersant.

Learning macroscopic equations of motion from dissipative particle dynamics simulations of fluids

Macroscopic descriptions of both natural and engineered materials usually include a number of phenomenological parameters that have to be estimated from experiments or large-scale microscopic simulations. When dealing with advanced complex materials, these descriptions are sometimes not a priori available or not even known. Using sparsity-promoting techniques one can extract macroscopic dynamic models directly from particle-based simulations. In this work, we showcase such an approach on a simple fluid and test its robustness. We introduce a novel measure for automatic macroscopic model selection that combines stability and accuracy of a model. Using this measure and employing only a few physics-based assumptions, we are able to infer both the mass continuity equation and an equation for the conservation of linear momentum. Moreover, the extracted phenomenological and non-phenomenological parameters agree well with their numerically measured values and the well-known semi-empirical estimates. The presented model selection framework can be applied to simulations or experimental data of more complex systems, described in general by a rich set of coupled nonlinear macroscopic equations.

Photo-responsive anti-fouling polyzwitterionic brushes: a mesoscopic simulation.

The antifouling effects of a toothbrush-shaped photo-responsive polyzwitterionic membrane were studied via dissipative particle dynamics simulations in this work. The results reveal that the membrane modified by spiropyran methacrylate brushes displays photo-switchable and antifouling capability due to the photo-induced ring-opening reaction. Namely, surface morphology and hydrophilicity change in response to visible or UV light irradiation, which can be observed visually by protein adsorption and desorption. Further study indicates that: (1) brush-modification density can influence the structure and properties of the membrane. With low modification density, systems cannot establish an intact selective layer, which hinders the antifouling ability; as the modification density increases, the intact selective layer can be formed, which is conducive to the expression of photo-responsiveness and antifouling capability. (2) Factors of toothbrush-hair length and grafting ratio can influence the establishment of a light-responsive surface: as the grafting ratio and toothbrush-hair length increase, the light-responsive surface is gradually formed, meanwhile, the antifouling ability can be continuously reinforced under UV light irradiation. (3) As the brushes switch into a zwitterionic merocyanine state under UV exposure, the selective layer swelling becomes stronger than that with a hydrophobic spiropyran state under visible exposure. This is owing to the enhanced interaction between zwitterionic brushes and water, which is the root of the antifouling effect. The present work is expected to provide some guidelines for the design and development of novel antifouling membrane surfaces.