Long-term Antibacterial Properties Research Articles

Improved anti-organic fouling and antibacterial properties of PVDF ultrafiltration membrane by one-step grafting imidazole-functionalized graphene oxide

At present, membrane fouling is a thorny issue that limits the development of polyvinylidene fluoride (PVDF) composite membrane, which seriously affects its separation performance and service lifespan. Herein, an imidazole-functionalized graphene oxide (Im-GO) with hydrophilicity and antibacterial performance was synthesized, and it was used as a modifier to improve the anti-organic fouling and antibacterial properties of PVDF membrane. The anti-organic fouling test showed that the maximum flux recovery ratios against bovine serum albumin and humic acid were 88.9% and 94.5%, respectively. Conspicuously, the grafted imidazole groups could effectively prevent the bacteria from growing on the membrane surface. It was gratifying that the antibacterial modifier Im-GO was almost not lost from the hybrid membranes even by the ultrasonic treatment, which was different from the conventional release-killing antibacterial agents. Owing to the long-term anti-organic fouling and antibacterial properties, Im-GO/PVDF hybrid membranes exhibit a great application potential in the fields of rough separation and concentration of biomedical products.

Poly(ionic liquid)-Based Efficient and Robust Antiseptic Spray.

Exploring efficient and robust antibacterial materials is crucially important for human health and ecological security. Compared with intrinsically antibacterial materials, materials modified with antibacterial agents either by chemical or physical modification can simultaneously maintain basic functions and antibacterial properties. In particular, physical modification with antiseptic sprays is quite suitable for large-size objects in our daily life but restricted by high volatility of the antibacterial agents or poor adhesion strength between the antibacterial agents and the targeted objects. In this paper, we report a poly(ionic liquid) (PIL-Cn)-based efficient and robust antiseptic spray that exhibits long-term antibacterial properties against both Gram-positive and Gram-negative bacteria on diverse substrates, including glass, PE, and cotton. It is believed that this work will provide an alternative for current antiseptic sprays for usage in our daily life and hospitals.

Engineering of Ag-nanoparticle-encapsulated intermediate layer by tannic acid-inspired chemistry towards thin film nanocomposite membranes of superior antibiofouling property

Biofouling severely limits the application of reverse osmosis (RO) for water treatment. In this work, a green surface in-situ reduction method based on the tannic acid-inspired chemistry was used to introduce silver nanoparticles (AgNPs) into the intermediate layer of a thin film nanocomposite (TFN) membrane, as effectively improved the anti-biofouling performance of the membrane without sacrificing its desalination performance. SEM, EDX, AFM, XPS, DSA, ATR-FTIR and zeta potential were used to characterize the membranes. The plate counting method and confocal laser scanning microscopy (CLSM) were used to evaluate the anti-biofouling performance. And the long-term Ag+ release rate was measured using ICP-MS. Compared with unmodified thin film composite (TFC) membranes, the permeation flux of TFN membrane is improved while retaining the salt rejection. By optimizing the soaking time of FeCl3 and AgNO3 on the PSF membrane surface during the preparation of the intermediate layer and the M-phenylenediamine (MPD) and trimesoyl chloride (TMC) concentration for the interfacial polymerization. A water flux of 34.5 ± 1.2 L/m2 h and a salt retention of 98.0 ± 0.3% were achieved under the operating pressure of 1.55 MPa and 25 °C, for a 2000 ppm NaCl solution. The killing rates of the membrane to E. coli and S. aureus are almost 100% for a 24 h and 48 h contacting time. The number of bacteria attached to the membrane surface is far less than that of the unmodified membrane. More importantly, the Ag+ release rate was stable and controllable, allowing for long-term antibacterial properties.

The Efficacy of Silver-Based Electrospun Antimicrobial Dressing in Accelerating the Regeneration of Partial Thickness Burn Wounds Using a Porcine Model.

(1) Background: Wounds with damages to the subcutaneous are difficult to regenerate because of the tissue damages and complications such as bacterial infection. (2) Methods: In this study, we created burn wounds on pigs and investigated the efficacy of three biomaterials: polycaprolactone-gelatin-silver membrane (PCLGelAg) and two commercial burn dressings, Aquacel® Ag and UrgoTulTM silver sulfadiazine. In vitro long-term antibacterial property and in vivo wound healing performance were investigated. Agar diffusion assays were employed to evaluate bacterial inhibition at different time intervals. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC) and time-kill assays were used to compare antibacterial strength among samples. Second-degree burn wounds in the pig model were designed to evaluate the efficiency of all dressings in supporting the wound healing process. (3) Results: The results showed that PCLGelAg membrane was the most effective in killing both Gram-positive and Gram-negative bacteria bacteria with the lowest MBC value. All three dressings (PCLGelAg, Aquacel, and UrgoTul) exhibited bactericidal effect during the first 24 h, supported wound healing as well as prevented infection and inflammation. (4) Conclusions: The results suggest that the PCLGelAg membrane is a practical solution for the treatment of severe burn injury and other infection-related skin complications.

In situ growth zeolite imidazole framework materials on chitosan for greatly enhanced antibacterial effect

Zeolite imidazole framework materials (ZIFs) are a new type of antibacterial material with high chemical and thermal stability, and good antibacterial effect. However, powder ZIFs materials have the disadvantages of difficult separation and easy aggregation, which limit their application. In this work, ZIFs and chitosan (CS) were compounded by in-situ growth method to prepare a new antibacterial agent. The synergism of CS and ZIFs can effectively promote antibacterial effect compared with CS and pristine ZIFs, and CS/ZIF-67(1:6) has the best antibacterial activity, and its inhibitory rate (in 15 h) of E. coli is 96.75%, and the inhibitory rate of S. aureus reaches as high as 100%. This composites can effectively cause bacterial cell membrane rupture and leakage of internal nucleic acid and protein, leads to achieve antibacterial effect, and also exhibit excellent long-term (at least 5 days) antibacterial properties, the leaching of cobalt is below than 0.5 mg·L−1, and this composites are with excellent bio-compatibility.

Investigation of the Long-Term Antibacterial Properties of Titanium by Two-Step Micro-Arc Oxidation Treatment

Recently, biofilm formation caused by bacterial adhesion and colonization has been recognized as the major cause of failure in orthopedic and dental implant surgeries. In this study, a customized micro-arc oxidation (MAO) treatment technique was developed to obtain desirable antibacterial properties on Ti surfaces. The two-step MAO treatment was applied in the fabrication of specimens with Ag and with/without Zn in their surface oxide layer. In order to simulate practical usage, surface analyses and immersion tests were performed to evaluate the incorporation of Ag and Zn into the resulting oxide layer and ion release behavior, respectively. Additionally, the antibacterial properties of the specimens after long-term immersion in physiological saline were evaluated using Gram-negative facultative anaerobic bacteria. The MAO-treated specimens containing Ag and Zn exhibited excellent antibacterial properties against Escherichia coli, which were sustained even after 6 months of immersion in physiological saline to simulate practical usage. Moreover, the Ag ions released from the surface oxide indicate the antibacterial properties of the specimen in the early stage, while the release of the corrosion products of Zn demonstrates its antibacterial properties in the later stage.

One-Step Preparation of Green Fabric for Continuous Antibacterial Applications

Abstract Polypropylene (PP) scaffolds are the most commonly used biomedical scaffolds despite their disadvantages, which include problems with adhesion, infection, and inflammatory responses. Here, we report on the successful development of a facile one-step method to fabricate a series of novel triclosan polydopamine polypropylene (TPP) composite scaffolds and thereby effectively improve the biocompatibility and long-term antibacterial properties of PP scaffolds. The antibacterial triclosan can effectively interact with dopamine during biocompatible polydopamine formation on the PP scaffold by one-step green fabrication. Thanks to the sustained release of triclosan from the biocompatible polydopamine coating, a 5 mm × 5 mm sample of TPP-coated scaffold made with a triclosan concentration of 8 mg·mL−1 (referred to herein as TPP-8) exhibited a continuous antibacterial effect against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) for more than 15 d, at maximum antibacterial volumes of 2 and 5 mL, respectively. Our study establishes a new direction for facile long-term antibacterial studies for medical applications.

Modified Nanofibrous Filters with Durable Antibacterial Properties.

The main aims of the research were to produce efficient nanofibrous filters with long-term antibacterial properties and to confirm the functionality of samples under real filtration conditions. A polyurethane solution was modified by micro- or nanoparticles of copper oxide in order to juxtapose the aggregation tendency of particles depending on their size. Modified solutions were electrospun by the Nanospider technique. The roller spinning electrode with a needle surface and static wire electrode were used for the production of functionalized nanofibers. The antibacterial properties of the modified nanofibrous layers were studied under simulated conditions of water and air filtration. Particular attention was paid to the fixation mechanism of modifiers in the structure of filters. It was determined that the rotating electrode with the needle surface is more efficient for the spinning of composite solutions due to the continuous mixing and the avoidance of particle precipitation at the bottom of the bath with modified polyurethane. Moreover, it was possible to state that microparticles of copper oxide are more appropriate antimicrobial additives due to their weaker aggregation tendency but stronger fixation in the fibrous structure than nanoparticles. From the results, it is possible to conclude that nanofibers with well-studied durable antibacterial properties may be recommended as excellent materials for water and air filtration applications.

Direct synthesis of silver nanoparticles modified spherical mesoporous silica as efficient antibacterial materials

The development of new antimicrobial agents that can overcome antibiotic-resistance and possess improved antibacterial activity is of important global need. A one-step process is demonstrated to prepare silver nanoparticle decorated MCM–41 type mesoporous silica nanoparticles (AgMSN, average diameter ~ 200–500 nm) using a novel cationic surfactant that does not lead to precipitation of AgBr. The resulting nanostructure was characterized using powder X-ray diffraction, nitrogen physisorption and chemisorption analyses, electron microscopy techniques, and UV–vis spectroscopy. Together, these data demonstrated the silver nanoparticles were uniformly dispersed on the MSN. Gram-negative E. coli K12 and Gram-positive B. subtilis were used to study the antibacterial properties of these nanocomposites by both the plate count method and optical density measurements. In the antibacterial tests for E. coli K12 and B. subtilis , the AgMSN exhibited low minimum inhibitory concentrations of 85 μg mL −1 AgMSN (Ag content 6.1 μg mL −1 ) and 90 μg mL −1 (Ag content is 6.4 μg mL −1 ), respectively, revealing the high antibacterial activity. Additionally, >95% growth reduction in continuous re-culturing tests (6 cycles, 25 days) at minimum bactericidal concentration demonstrate excellent long-term antibacterial activity of AgMSN. The nanocomposites showed excellent antibacterial activity against both. These results demonstrate that AgMSN composites possess great potential as an antibacterial material. Silver nanoparticle decorated MCM–41 type mesoporous silica nanoparticles (AgMSN) have been synthesized by a one-step process which exhibits excellent long-term antibacterial activity against E. coli K12 and B. subtilis . • Silver nanoparticle decorated MCM–41 type mesoporous silica nanoparticles. • A one-step process of synthesis without using any reducing agent. • Excellent antibacterial activity against both Gram-positive and Gram-negative bacteria. • Re-culturing test to prove long-term antibacterial property. • Study of antibacterial mechanism.

Antifouling and antibacterial behavior of membranes containing quaternary ammonium and zwitterionic polymers

To overcome the organic-/bio- fouling of the membrane, a dual-functional ultrafiltration membrane containing quaternary ammonium and zwitterionic polymers via quaternization and surface radical polymerization was designed, and its antifouling and antibacterial behavior was studied. In this work, poly(vinylidene fluoride)/poly(methyl methacrylate-co-dimethylamino-2-ethyl methacrylate) (PVDF/P(MMA-co-DMAEMA)) blend membrane was quaternized by p-chloromethyl styrene (p-CMS), and the double bonds were introduced onto the membrane surface, which further participated in the polymerization of zwitterionic monomers on the membrane surface. The results indicated that the resultant membrane exhibited obviously improved hydrophilicity and weak positive charge (isoelectric point, 7.49). The membrane presented higher flux recovery ratio and lower protein adhesion compared with the pure PVDF membrane. Meanwhile, the membrane showed high-efficiency broad-spectrum antibacterial performance, that is, the bacteria killing efficiency of S. aureus and E. coli reached 98.2% and 97.0%, respectively. Moreover, the membrane effectively inhibited bacterial adhesion, which is important for the long-term antibacterial properties of membrane. This antifouling and antibacterial PVDF membrane may have potential in the long-term filtration process, especially when dealing with microbiologically contaminated water.

Two silver-based coordination polymers constructed from organic carboxylate acids and 4, 4′-bipyridine-like bidentate ligands: Synthesis, structure, and antimicrobial performances

Two silver-based coordination polymers, [Ag2(O-IPA)(H2O)]·(H3O) (CP1) and [Ag2(bpe)2(Cl)2] (CP2), were facilely synthesized from AgNO3 and 5-hydroxyisophthalic acid (HO-H2IPA)/1,1′-(1,4-phenylene-bis(methylene))-bis(pyridine-3-carboxylic acid) (1pbb3ca) and 1,2-di(4-pyridyl)ethylene (bpe) by the slow evaporation method at room temperature. These two coordination polymers exhibited excellent and long-term antibacterial properties toward Gram-negative bacteria named Escherichia coli (E. coli), in which CP1 achieved the lowest minimum inhibitory concentration (MIC) of 5 ppm and largest inhibition zone of 11.12 mm due to its fastest Ag+ release rate and highest equilibrium concentration. These coordination polymers could destroy the membrane of the bacteria, leading to the death of cells. The stable and slow release of Ag+ ions in aqueous solutions for 5 d ensure the potentially further application in the purification of polluted water or medical purpose.

Physicochemical properties and antibacterial mechanism of TP microcapsules/LZM-PVA gradual sustained-release composite coatings

Tea polyphenol (TP) has excellent preservation effect on the aquatic product, however, its long-term antibacterial and preservation property is poor due to its volatilization. Therefore, a novel sustained –release formulation of TP should be developed for improving the applicability. In this study, the TP microcapsules/LZM-PVA composite coatings with gradual slow release properties were prepared by tape-casting method. Its micro-morphology was characterized and its physicochemical properties were determined. Meanwhile, the antibacterial properties and mechanism of the composite coatings were studied with Pseudomonas fluorescens and Shewanella putrefaciens, the dominant spoilage bacteria in aquatic products, as the objects. The results show that the addition of TP and other substances affects the structure of PVA coatings, and changes the intermolecular force of PVA, the coatings is wrinkled and denser, which effectively improve the mechanical properties of the PVA coatings, and finally lead to the decrease of air permeability. Among them, the TP microcapsules/LZM-PVA composite coating has the best mechanical properties, the least amount of CO2 and water vapor penetration. The results of antibacterial experiments show that the PVA coating without preservatives has no antibacterial property. Compared with the bacterial cells treated by the corresponding composite coatings without LZM, the integrity of the cell membrane is poor and the permeability is higher after treated by the composite coating with LZM, which is due to the synergistic antibacterial effect of TP and LZM. More importantly, when TP is replaced by TP microcapsules, the antibacterial ability of the composite coatings is poor at the initial stage. However, TP is embedded in the space network structure formed by CS-sodium tripolyphosphate. TP in the coatings can be released slowly from microcapsules to coatings, and then from coatings to the culture medium, which prolong the antibacterial effect time and cause continuous damage to the bacteria. Moreover, the chitosan which is the wall material of TP microcapsules also has a certain antibacterial effect. So the TP microcapsules/LZM-PVA coating could be an ideal choice in the food preserving.

Investigation of antibacterial effect of copper introduced titanium surface by electrochemical treatment against facultative anaerobic bacteria.

This study investigated the efficacy of copper (Cu) as an antibacterial element incorporated on titanium (Ti) surface by electrochemical treatment. Cu was incorporated onto Ti surface by micro-arc oxidation (MAO). A small amount of Cu was incorporated into the oxide layer and was found to be in oxidized states. Cu-incorporated samples exhibited no-harmful effect on the proliferation of osteoblastlike cells. Moreover, the difference in antibacterial property between fresh and incubated samples was evaluated using gram-positive and gram-negative facultative anaerobic bacteria. The specific antibacterial property of Cu incorporated into the Ti surface were confirmed. The antibacterial property prolonged upon immersion in physiological saline for 28 days. In other words, MAO-treated Ti containing Cu in this study is expected to achieve long-term antibacterial property in practical usage.

Biological and antibacterial properties of TiO2 coatings containing Ca/P/Ag by one-step and two-step methods.

The porous TiO2 coatings containing Ca/P/Ag were separately prepared on titanium (Ti) surface by one-step (micro-arc oxidation) and two-step methods (micro-arc oxidation and cathodic deposition), and then their surface morphology, composition, biological and antibacterial properties were compared. The results showed that the porous coatings containing Ca/P/Ag achieved by different methods showed similar surface morphology and elemental composition, however, by one-step method, silver existed in the coating as silver phosphate, while in the coatings prepared by two-step method, silver existed as metallic silver. Although both coatings showed excellent antibacterial property (the antimicrobial rate is over 99.9%), the surface coating prepared by one-step method had a more suitable release curve of Ag. In addition, the surface coating prepared by one-step method also presented better biological property, which was due to its enhanced surface roughness and hydrophilicity. Combining with its easy operation and long-term antibacterial property, its prospect for clinical application is more promising.

Layer-by-layer immobilizing of polydopamine-assisted ε-polylysine and gum Arabic on titanium: Tailoring of antibacterial and osteogenic properties.

Bacterial infection has become a crucial reason that give rise to failure of medical implants in clinical applications. In this regard, various antibacterial surface modifications of implants have been developed in recent years. However, it remains a challenge to enable the implant surfaces with both suitable antibacterial and osteogenic properties. In this work, ε-polylysine and gum Arabic multilayer composite films were immobilized layer by layer (LBL) on anodized titanium with the assistance of polydopamine for the first time. In vitro antibacterial results showed that the bacteria numbers decreased with an increase in the loading amount of ε-polylysine. Furthermore, long-term antibacterial property up to 3weeks against both gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) was obtained combined with the merits of covalent binding and LBL methods. Meanwhile, the cell proliferation and osteogenic differentiation of BMSCs on titanium dioxide nanotubes (TNTs) modified with composite films was significantly improved. Remarkably, a facile method to optimize anti-infective and osteogenic properties of medical titanium has been developed, and it was demonstrated that the ε-polylysine and gum Arabic multilayer composite films with assistance of polydopamine were able to endow the orthopedic implant materials both improved antibacterial property and excellent biocompatibility, which is of profound significance for practical application of titanium-based implants.

Zinc-/copper-substituted dicalcium silicate cement: advanced biomaterials with enhanced osteogenesis and long-term antibacterial properties.

The development of bioactive Ca-silicate-based cements which may simultaneously suppress infection is promising for periapical therapy or alveolar bone defect repair. While these treatments are usually effective in the short term, many of these cements have not been designed to have an affinity with dental tissue in a prolonged anti-infectious manner and are only high alkaline in the early stages. This can lead to less favorable long-term outcomes, such as in bone repair or secondary therapy. Inspired by the strong antibacterial activity of zinc and copper ions, we developed a nonstoichiometric dicalcium silicate (C2S) substituted by 5% or 10% Zn or Cu to endow it with appropriate multifunctions. It was found that the foreign ion substitution could inhibit free CaO content and increase the pH value in the initial ∼6 h. The C2S cement only showed antibacterial activity in the early stage (6-72 h), but the C2S displayed appreciable long-term antibacterial potential against P. aeruginosa, E. faecalis and E. coli (>6 h) and S. aureus (>72 h). Moreover, the enhanced new bone regeneration by Zn substitution in C2S was confirmed in a maxillofacial bone defect model in rabbits. The increases in new bone formation adjacent to C2S-10Zn and C2S after 16 weeks of implantation were 32% and 20%, respectively. And the Tb.N values in the C2S-10Zn and C2S-10Cu groups (∼5.7 and 4.9 mm-1) were over two-fold higher than in the C2S group (∼2.0 mm-1). It is considered that Zn- or Cu-substitution in C2S is promising for applications to infectious bone repair.

The preparation of a difunctional porous β-tricalcium phosphate scaffold with excellent compressive strength and antibacterial properties.

Porous β-tricalcium phosphate (β-Ca3(PO4)2, β-TCP) scaffolds are widely applied in the field of bone tissue engineering due to their nontoxicity, degradability, biocompatibility, and osteoinductivity. However, poor compressive strength and a lack of antibacterial properties have hindered their clinical application. In order to address these disadvantages, graphene (G) and silver nanoparticles were introduced into β-TCP through a two-step method. In the synthesis process, G-β-TCP was prepared via an in situ synthesis method, and then silver nanoparticles and HAp particles were coated on the surface of the G-β-TCP scaffold in an orderly fashion using dopamine as a binder. From the results of characterization, when the content of graphene was 1 wt% of β-TCP, the G-β-TCP scaffold had the highest compression strength (127.25 MPa). And core–shell G-β-TCP-Ag-HAp not only had reduced cytotoxicity via the continuous release of Ag+, but it also achieved long-term antibacterial properties. Besides, the material still showed good cell activity and proliferation.

Copper-doped 3D porous coating developed on Ti-6Al-4V alloys and its in vitro long-term antibacterial ability

In this study, 3D porous anodic coatings containing 1.92 wt% copper (Cu-1.92 wt%) are developed on Ti-6Al-4V alloys via micro-arc oxidation (MAO). The in vitro long-term antibacterial activity of the MAO-treated samples is systematically evaluated. The results show that after 14 days’ immersion in Hanks’ solution, the antibacterial rate of Cu-1.92 wt% against Staphylococcus aureus (S. aureus) remains at 100%, while that against Escherichia coli (E. coli) decreases to 92% and 12% after 8 and 14 days, respectively, suggesting that Cu-1.92 wt% still exhibits good long-term antibacterial properties even after 14 days. Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) analysis and reactive oxygen species (ROS) fluorescence imaging reveal that the antibacterial efficiency of Cu-1.92 wt% is higher than those of Cu-1.92 wt%-8D, Cu-1.92 wt%-14D, and the untreated control. The enhanced antibacterial properties of the MAO samples are attributed to ROS-mediated DNA damage prompted by the presence of Cu in the coatings. In addition, Cu-1.92 wt% favors good initial cell adhesion and high cell viability. These results reveal that the fabricated biocompatible copper-doped 3D porous coatings exhibit good in vitro long-term antibacterial properties and have potential to be applied in the orthopaedics clinic in the future.

Mussel-inspired fabrication of cationic polymer modified rGO supported silver nanoparticles hybrid with robust antibacterial and catalytic reduction performance

Mussel-inspired strategy was developed to fabricate quaternized polymer modified reduced graphene oxide supported silver nanoparticles hybrid (rGO-QCP-Ag) for efficient antibacterial agent and nanocatalyst. The rGO-QCP-Ag nanohybrid had high positive charge density and decent hydrophilic properties, and the Ag nanoparticles deposited on rGO exhibited ultra-small size and dispersion stability. The as-prepared nanohybrid showed high-efficacy and long-term antibacterial properties against E. coli (G−) and S. aureus (G+), especially, it could rapidly kill E. coli within 2 h at a concentration of 16 μg/mL. The antibacterial mechanism of nanohybrid mainly involved cell membrane damage and ROS generation. In addition, the nanohybrid displayed highly efficient catalytic reduction for p-nitrophenol and methylene blue. The excellent antibacterial and catalytic properties of the nanohybrid were mainly attributed to its water dispersion stability and the uniformly dispersed small-sized Ag nanoparticles on the polymer-decorated rGO sheets. Meanwhile, combining with the synergistic effect of two-dimensional rGO sheets, the above properties enable the nanohybrid to get in contact with bacteria and reactants effectively, enhancing the antimicrobial and catalytic properties. The excellent properties of the as-designed nanohybrid are expected to solve the problem of bacterial resistance and environmental pollution that is threatening public health.

Antifouling and antibacterial behaviors of capsaicin-based pH responsive smart coatings in marine environments.

Antifouling biocides releasing restricts the longevity of antifouling coatings. Compared with the anchoring state, the releasing behavior of agents is much faster on the voyage, while the biofouling process is tougher. In this work, a series of capsaicin-based pH-triggered polyethylene glycol/capsaicin@chitosan (PEG/CAP@CS), polyvinyl alcohol (PVA)/CAP@CS and alginate (ALG)/CAP@CS multilayer films are prepared with controlling antimicrobial properties in marine environments. There are 23.70, 23.35 and 22.06 ppb CAP releasing from (PVA/CAP@CS)20, (PEG/CAP@CS)20 and (ALG/CAP@CS)20 films after immersing in pH 4 solutions for 60 days, while only 13.07, 12.95 and 11.55 ppb CAP have been found in alkaline solutions after immersing for the same time, respectively. All these three types of films exhibit extraordinary pH responsive properties. They can control the CAP release at a low level in alkaline solutions, and make the CAP release fast in acid solutions. Moreover, the antibacterial properties against P.aeruginosa are outstanding about 95.84%, 95.0% and 96.91% for (PVA/CAP@CS)20, (PEG/CAP@CS)20 and (ALG/CAP@CS)20 films, respectively. The bacteriostasis of (ALG/CAP@CS)20 film keeps 92.73% after 60 days in alkaline solution, which means it is steadily controlled in the marine environment. Although with similar antibacterial properties to those of (PEG/CAP@CS)20 film, (PVA/CAP@CS)20 film displays the maximum decrease with about 92% in acid solution after 60 days. The ALG/CAP@CS film with the best-controlled release performance and long-term antibacterial properties provides novel guidance for developing new antifouling coatings application in the marine environment.