Synthesis of HAP coating on galvanostatically treated stainless steel substrates by sol–gel method

Producing bioactive hydroxyapatite coatings on metallic implant materials combines the mechanical advantages of implant materials and biological affinity of the hydroxyapatite surface to the natural tissue. In this work, hydroxyapatite was synthesized on 316L stainless steel substrates via sol–gel method by using Ca(NO₃)₂·4H₂O and C₆H₁₅O₃P. In order to improve adherence of the coatings produced, the surface of the substrate was initially modified by electrodepositing nucleus of calcium phosphate compounds. Effect of aging time for preparation of the sol solution and coating characteristics were investigated. The phase compositions and structures of the coatings were characterized by X-ray diffractometry, and scanning electron microscopy was used to determine morphological characteristics of the coatings. Adhesion between the hydroxyapatite coating and the substrate was investigated by using scanning scratch tester. The coating produced on the modified surface by the sol solution aged for 24 h was found to prove better morphological and adhesion properties.     

Adhesion of electron-beam cured coatings to steel sheets—Effects of formulations and primers

Factors affecting adhesion properties of electron-beam cured coatings were investigated using acrylic oligomers prepared via cationic copolymerization and galvannealed or primer-coated steel sheets. An oligomer-monomer mixture with a polar component gave coatings with better adhesion to the galvannealed steel sheet, while a mixture without any polar component showed better adhesion to the other substrate. In the latter case, the adhesion depended convexly downwards on glass transition temperatures (T_g) of the primers, which indicated chemical bonding between two coatings at higher T_g. The addition of a EB-curable resin containing hydroxy moieties to primer coatings increased the adhesion.     

Adhesion strength of filled polyaluminosilicates on aluminum surface

Study of the adhesion of coatings based on polyaluminosilicates of dendrimer structure, deposited on an aluminum surface of complex morphology with roughnesses R _a = 0.05–11.30 μm, demonstrated that the adhesion strength of the sample with R _a = 11.30 μm is 16 times that of a samples with a polished surface (R _a = 0.05 μm) and 2.3 times that of the coating deposited on the surface produced by microarc oxidation. It was demonstrated that the values obtained for the work of adhesion are well correlated with the parameters of profilograms, which is particularly important for choosing the composition of coatings and prognosticating their adhesion under working conditions.     

An innovative, easily fabricated, silver nanoparticle-based titanium implant coating: development and analytical characterization

Microbial colonization and biofilm formation on implanted devices represent an important complication in orthopaedic and dental surgery and may result in implant failure. Controlled release of antibacterial agents directly at the implant site may represent an effective approach to treat these chronic complications. Resistance to conventional antibiotics by pathogenic bacteria has emerged in recent years as a major problem of public health. In order to overcome this problem, non-conventional antimicrobial agents have been under investigation. In this study, polyacrylate-based hydrogel thin coatings have been electrosynthesised on titanium substrates starting from poly(ethylene glycol diacrylate)–co–acrylic acid. Silver nanoparticles (AgNPs) with a narrow size distribution have been synthesized using a “green” procedure and immobilized on Ti implant surfaces exploiting hydrogel coatings’ swelling capabilities. The coatings have been characterized by XPS and SEM/EDX, while their silver release performances have been monitored by ICP–MS. The antibacterial activity of these AgNP-modified hydrogel coatings was tested evaluating in vitro inhibition growth of Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli, among the most common pathogens in orthopaedic infections. Moreover, a preliminary investigation of the biocompatibility of silver-loaded coatings versus MG63 human osteoblast-like cells has been performed. An important point of strength of this paper, in fact, is the concern about the effect of silver species on the surrounding cell system in implanted medical devices. Silver ion release has been properly tuned in order to assure antibacterial activity while preserving osteoblasts’ response at the implant interface.

Study of Titanium–Silver Monolayer and Multilayer Films for Protective Applications in Biomedical Devices

The search for coatings that extend the useful life of biomedical devices has been of great interest, and titanium has been of great relevance due to its innocuousness and low reactivity. This study contributes to the investigation of Ti/Ag films in different configurations (monolayer and multilayer) deposited by magnetron sputtering. The sessile droplet technique was applied to study wettability; greater film penetrability was obtained when Ag is the external layer, conferring high efficiency in cell adhesion. The morphological properties were characterized by SEM, which showed porous nuclei on the surface in the Ag coating and crystals embedded in the Ti film. The structural properties were studied by XRD, revealing the presence of TiO₂ in the anatase crystalline phase in a proportion of 49.9% and the formation of a silver cubic network centered on the faces. Tafel polarization curves demonstrated improvements in the corrosion current densities of Ag/Ti/Ag/Ti/Ag/Ti/Ag/Ti and Ti/Ag compared to the Ag coating, with values of 0.1749, 0.4802, and 2.044 nA.m⁻², respectively. Antimicrobial activity was evaluated against the bacteria Pseudomonas aeruginosa and Bacillus subtilis and the yeasts Candida krusei and Candida albicans, revealing that the Ti/Ag and Ag/Ti/Ag/Ti/Ag/Ti/Ag/Ti coatings exhibit promise in biomedical material applications.     

Influence of process parameters on the sol–gel synthesis of nano hydroxyapatite using various phosphorus precursors

Hydroxyapatite Ca₁₀(PO₄)₆(OH)₂ has attracted widespread interest from both orthopedic and dental fields due to its excellent biocompatibility and tissue bioactivity properties. Since nanophase materials can mimic the dimensions of constituent components of natural tissues, the implants developed from nanophase material could serve as a successful alternative. However, the defects of hydroxyapatite ceramics, mainly brittleness and low fracture toughness, have been overcome by the use of nanophase hydroxyapatite coatings on the implant surfaces that integrate the good mechanical properties of metals and the bioactivity of hydroxyapatite. In the present investigation, Sol?Cgel hydroxyapatite was prepared from two different phosphorus precursors such as triethyl phosphate and phosphorus pentoxide respectively with calcium nitrate tetrahydrate as a calcium precursor. The effects of pH and liquid P³¹ Nuclear Magnetic Resonance spectroscopy for the solution aged at different periods were investigated and the synthesized hydroxyapatite powder was characterized by Transmission electron microscopy, X-ray Powder Diffraction, Fourier transform infrared spectroscopy and thermal analysis respectively. In order to fully understand the bioactivity of the synthesized materials, they were coated on 316L Stainless Steel implant surface by spin coating method at the spin speed of 2,000 Revolutions per minute. The effect of nanoparticles on the surface of 316L Stainless Steel implant was studied by adhesive strength measurements. The corrosion resistance property of the hydroxyapatite coatings was evaluated by electrochemical impedance analysis. From the results, it was observed that the hydroxyapatite coatings obtained from different precursors have very high resistance to corrosion with higher adhesive strength.     

XPS Analysis and Antibacterial Assay of Novobiocin Coating

Infection disease after biomedical implant surgery is often caused by unintentional contamination of micro-organism. Novobiocin is one of the most attractive antibiotic due to its high activity against gram positive bacteria and its relatively compatible to fibroblast cell line. Based on the molecular structure of novobiocin, it may be conjugated or coated onto material surfaces. The coating steps were plasma polymerisation, polymer grafting, and novobiocin conjugation. XPS analysis showed that the elements and high resolution of C 1s confirmed that the surface chemical had changed. Novobiocin, after conjugation, became more dominant in covering the surface. Antibacterial Assay to Staphylococcus epidermidis by using dead and live kit indicated the reduction of bacteria reached up to 97.27% and only 0.07% of live bacteria left. This result led to a conclusion that immobilised novobiocin may be considered as novel antibacterial coating that can prevent nosocomial infection.     

Decontamination-Induced Modification of Bioactivity in Essential Oil-Based Plasma Polymer Coatings

Plasma polymer coatings fabricated from Melaleuca alternifolia essential oil and its derivatives have been previously shown to reduce the extent of microbial adhesion on titanium, polymers, and other implantable materials used in dentistry. Previous studies have shown these coatings to maintain their performance under standard operating conditions; however, when used in e.g., a dental implant, these coatings may inadvertently become subject to in situ cleaning treatments, such as those using an atmospheric pressure plasma jet, a promising tool for the effective in situ removal of biofilms from tissues and implant surfaces. Here, we investigated the effect of such an exposure on the antimicrobial performance of the Melaleuca alternifolia polymer coating. It was found that direct exposure of the polymer coating surface to the jet for periods less than 60 s was sufficient to induce changes in its surface chemistry and topography, affecting its ability to retard subsequent microbial attachment. The exact effect of the jet exposure depended on the chemistry of the polymer coating, the length of plasma treatment, cell type, and incubation conditions. The change in the antimicrobial activity for polymer coatings fabricated at powers of 20–30 W was not statistically significant due to their limited baseline bioactivity. Interestingly, the bioactivity of polymer coatings fabricated at 10 and 15 W against Staphylococcus aureus cells was temporarily improved after the treatment, which could be attributed to the generation of loosely attached bioactive fragments on the treated surface, resulting in an increase in the dose of the bioactive agents being eluted by the surface. Attachment and proliferation of Pseudomonas aeruginosa cells and mixed cultures were less affected by changes in the bioactivity profile of the surface. The sensitivity of the cells to the change imparted by the jet treatment was also found to be dependent on their origin culture, with mature biofilm-derived P. aeruginosa bacterial cells showing a greater ability to colonize the surface when compared to its planktonic broth-grown counterpart. The presence of plasma-generated reactive oxygen and nitrogen species in the culture media was also found to enhance the bioactivity of polymer coatings fabricated at power levels of 10 and 15 W, due to a synergistic effect arising from simultaneous exposure of cells to reactive oxygen and nitrogen species (RONS) and eluted bioactive fragments. These results suggest that it is important to consider the possible implications of inadvertent changes in the properties and performance of plasma polymer coatings as a result of exposure to in situ decontamination, to both prevent suboptimal performance and to exploit possible synergies that may arise for some polymer coating-surface treatment combinations.     

Experimental investigation of the adhesion force of single and double-layer coatings on MEMS surfaces

Adhesion force is one of the most important factors in microelectromechanical systems (MEMS), especially for microassembly. It depends on operating conditions and is affected by the contact area. In this study, the adhesion force between MEMS materials and AFM tips was analysed using AFM's point-mode spectroscopy. The aim was to study the effectiveness of various coatings in MEMS adhesion surfaces. For this purpose, five silicon surfaces were used, four of which were coated, and one was noncoated. Two of them were deposited by single-layer coating (Au and Ag). The other two were deposited by double-layer coating (TiO₂/Au, TiO₂/Ag) on a Si (1 0 0) substrate. The depositing was accomplished by the thermal evaporation method. Composite materials and analysis were reviewed by observing the SEM image. The experimental results showed that the method of deposition helped to decrease the adhesion force between the probe tip and the surface of the specimens, and double-layer coating had stronger effect on decreasing the adhesion force than the single-layer coating.     

Improved UV stability of antibacterial coatings with N-halamine/TiO2

The outstanding advantages of N-halamine materials over other antimicrobial materials are their durable and rechargeable antimicrobial properties, as well as their efficacies in inactivating a broad spectrum of pathogens. Theoretically, the oxidative chlorine of antimicrobial cotton coated with N-halamine hydantoin diol can be restored upon loss of its biocidal efficacy after exposure to ultraviolet light. In this work nano-titania particles were added into the coating solutions containing N-halamine diol and 1,2,3,4-butanetetracarboxylic acid (BTCA), and the coatings were applied to produce antimicrobial cellulose with improved UV stability. The treated cotton fabrics were characterized by FT-IR, SEM, XRD, and XPS. The effects of the coatings on tensile strength and wrinkle recovery angle were investigated. Biocidal efficacies of fabrics coated with hydantoin diol and diol/TiO₂ against Staphylococcus aureus (ATCC 6538) and Escherichia coli O157:H7 (ATCC 43895) were determined using a modified AATCC 100-1999 method and showed excellent antimicrobial properties against these two bacterial species within a brief contact times. It was found that the addition of Nano-TiO₂ in the antimicrobial coatings, especially rutile titanium dioxide, could improve the UV light stability of the chlorinated fabrics coated with hydantoin diol significantly. The UV light stability of N-halamine coatings were enhanced with increasing amounts of rutile TiO₂.     

Biological responses to silicon and nitrogen-rich PVD silicon nitride coatings

Most structural bioceramics are comprised of metallic oxides such as alumina and zirconia. They are generally considered to be completely bioinert, but a non-oxide ceramic, silicon nitride, achieves equivalent levels of mechanical reliability while being bioactive. Silicon nitride can not only stimulate cellular proliferation but it is also antipathogenic with demonstrated efficacy against Gram-positive and Gram-negative bacteria, fungi, and viruses. In this work, three physical vapor deposition coatings with different Si:N ratios (silicon-rich, stoichiometric, and nitrogen-rich) were deposited on mirror-polished silica glass substrates. The coatings were characterized by spectroscopic and microscopic techniques and tested in vitro against E. coli and KUSA-A1 mesenchymal cells. Results showed that nitrogen-enriched Si_xN_y has a strong antibacterial effect against E. coli and contributes to cellular proliferation while silicon-enriched Si_xN_y stimulates the production of bone tissue, with higher indexes for mineralization and quality. These results suggest that Si_xN_y's biological properties can be optimized for specific applications by carefully tuning its surface chemistry.     

Rheological and antimicrobial properties of epoxy-based hybrid nanocoatings

The modification of nanocomposite coatings with fillers having unique characteristics in the polymeric matrix is a promising strategy to enhance the durability as well as to prevent the growth of microorganisms that decrease the stability of the materials. This study was conducted to evaluate the rheological and antimicrobial behavior of epoxy-based nanocomposite coatings filled with nanosilica, titanium oxide (TiO₂) and zinc oxide (ZnO) against Staphylococcus aureus and Escherichia coli. A rheometer was used for characterizing the rheological properties of the various fillers embedded epoxy nanocomposite coatings. All of the composites inhibited the growth of Staphylococcus aureus and Escherichia coli on modified Kirby Bauer antimicrobial testing, only when they are in contact with samples. Upon quantitative analysis, bioactive constituent dependent antimicrobial activity was observed which increased with the exposure of contact times. The epoxy/silica/TiO₂/ZnO (ESTZ) coating showed the highest bacterial reduction of more than 95% for 4 h of treatment. The bioactivity was decreased for the case of epoxy/silica/ZnO (ESZ) or epoxy/silica/TiO₂ (EST). The combined effect of the nanosilica, TiO₂, and ZnO shows the highest performance in terms of stress, viscosity and torque compared to the individual effect of these three fillers onto the epoxy. Results showed that the shear stress of ESZ, EST, epoxy/silica (ES), and ESTZ coating was increased by 4.4%, 7.7%, 32.2%, and 42%, respectively, compared to the neat epoxy (NE) coating. The torque versus strain curve also showed that the torque of ESTZ composites was the highest (0.52 mN m) compare to NE (0.36 mN m), ESZ (0.38 mN m), EST (0.40 mN m), and ES (0.45 mN m). The studies indicate that the epoxy-based thermoset nanocomposite coatings can be utilized as bactericidal surfaces for the industrial and medical purpose to reduce microbial growth.     

Microfibrillated cellulose (MFC): pullulan bionanocomposite films

The aim of this work was to develop and characterize microfibrillated cellulose (MFC)/pullulan bionanocomposites. Fourier transform infrared spectroscopy suggested that the affinity between the two polymers resulted in new hydrogen bonding of the nanocomposite materials compared to pristine pullulan. At the same time, an increase in crystallinity was observed proportional to the amount of MFC used, as shown by the X-ray analyses. Accordingly, final films showed improved mechanical properties proportionally to the filler loading, with impressive elastic modulus and tensile strength of ~4.50 GPa and ~60 MPa, respectively, for the sample containing 10 % MFC. However, as demonstrated by the moisture sorption isotherms, the addition of MFC did not help reduce the amount of water adsorbed by the samples. In addition, the oxygen and water vapor permeability data clearly showed that final films still suffered high relative humidity values, whereas their barrier performance toward oxygen was excellent under dry conditions, with O₂ permeability coefficients (P′O ₂) comparable with those of common high barrier films/coatings. Finally, while the nanocomposites in the form of films had high haze values (from 23 to 40 %), the same nanocomposites in the form of coatings were decidedly more transparent, which suggests that their use as thin layers could be more suitable when the “see-through” capability must be preserved, for example in food packaging applications.     

CO<Subscript>2</Subscript> Biofixation of <Emphasis Type="Italic">Actinobacillus succinogenes</Emphasis> Through Novel Amine-Functionalized Polystyrene Microsphere Materials

CO₂-derived succinate production was enhanced by Actinobacillus succinogenes through polystyrene (PSt) microsphere materials for CO₂ adsorption in bioreactor, and the adhesion forces between A. succinogenes bacteria and PSt materials were characterized. Synthesized uniformly sized and highly cross-linked PSt microspheres had high specific surface areas. After modification with amine functional groups, the novel amine-functionalized PSt microspheres exhibited a high adsorption capacity of 25.3 mg CO₂/g materials. After addition with the functionalized microspheres into the culture broth, CO₂ supply to the cells increased. Succinate production by A. succinogenes can be enhanced from 29.6 to 48.1 g L^?1. Moreover, the characterization of interaction forces between A. succinogenes cells and the microspheres indicated that the maximal adhesive force was about 250 pN. The amine-functionalized PSt microspheres can adsorb a large amount of CO₂ and be employed for A. succinogenes anaerobic cultivation in bioreactor for high-efficiency production of CO₂-derived succinate.     

造孔剂对电泳沉积制备多孔HA涂层及其生物活性的影响

采用水热法制得的羟基磷灰石(HA)纳米粉体,分别与造孔剂葡萄糖(Glu)、壳聚糖(CS)、炭粉(C)3种微粒(＜38.5 μm)配置成质量比1∶1的悬浮液,电泳沉积 烧结制备钛基多孔HA涂层,并对制得的3种多孔HA涂层在模拟体液浸泡前后的表面形貌、化学组成及物相变化进行表征。 结果表明,经700 ℃烧结处理后制得的3种多孔HA涂层在1.5倍人体模拟体液中浸泡5 d后,多孔HA涂层表面均被层状生长的碳磷灰石颗粒完全覆盖,颗粒直径在5~25 μm,说明这些多孔HA涂层均具有良好的生物活性。 其中以CS为造孔剂制得的多孔HA涂层结合强度最高,达19.5 MPa,有望开发成为新型的人骨植入生物陶瓷材料。     

Strontium-doped hardystonite plasma sprayed coatings with robust antimicrobial activity

A strontium-doped hardystonite (Sr-HT) bioceramic, in bulk form, demonstrates excellent bioactivity for bone regeneration with high fracture toughness and compressive strength. This work examines the antibacterial and mechanical properties of Sr-HT coatings on an alpha-beta titanium alloy with a high specific strength and excellent corrosion resistance (Ti-6Al-4V) produced by atmospheric plasma spray (APS) as the deposition coating technique. A hydroxyapatite (HAp) APS coating, a commercial bioceramic coating, is chosen as the control. The in-situ observation showed that Sr-HT powders experience temperatures during plasma processing that exceeded their melting point to form a coating well adhered to the substrate. It was demonstrated that the Sr-HT coating possessed superior antibacterial properties against Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative Pseudomonas aeruginosa. In addition, the Sr-HT coating exhibits a uniform distribution of hardness and elastic moduli, higher nanohardness and elastic moduli compared to the equivalent properties of the HAp coating. Moreover, the Sr-HT coating outperforms the HAp coating regarding scratch and wear resistance. The bonding and shear strength of the Sr-HT coating are higher than the values required for orthopedic implant coatings. The Sr-HT coating also allows efficient zinc, silicon and strontium ions release when immersed in cell culture media. In summary, the antibacterial capabilities and the mechanical properties of the Sr-HT APS coating exceed those of the commercial HAp APS coating. Therefore, Sr-HT APS coatings are candidates for bioceramic coating applications in orthopedic implants.     

In vitro and in vivo evaluation of the antibacterial properties of a nisin-grafted hydrated mucin multilayer film

Microbial infection is one of the most serious problems in the field of medical devices, particularly in implants. Herein, we have designed and constructed a (mucin/poly(ethyleneimine))_n ((mucin/PEI)_n) multilayer film using a layer-by-layer self-assembly method and the grafting of antimicrobial peptides to enhance the bactericidal efficacy. Water contact angle measurements and atomic force microscopy images revealed that the hydrated multilayer film created a highly hydrophilic surface with a low roughness. The functionalized polydimethylsiloxane (PDMS) surfaces were shown to be effective in preventing bovine serum albumin (BSA) adsorption and in reducing bacterial adhesion. Bactericidal activity of the (mucin/PEI)_n-nisin coatings, measured by scanning electron microscopy and a LIVE/DEAD bacterial viability kit, was remarkably effective against S. aureus owing to the grafting of nisin. In vivo subcutaneous incisions were made in New Zealand white rabbits and were implanted with multilayer-film-modified and uncoated PDMS. Both the evaluation of the appearance of the wound and the histopathology analysis demonstrated that implantation of the antibacterial-coating-modified PDMS promoted wound healing and showed an anti-inflammatory effect. The multilayer film proved to be nontoxic towards human lens epithelial cells, which can potentially be widely used to modify biomedical implants.     

Secretory Phospholipase A2 in Dromedary Tears: a Host Defense Against Staphylococci and Other Gram-Positive Bacteria

The best known physiologic function of secreted phospholipase A₂ (sPLA₂) group IIA (sPLA₂-IIA) is defense against bacterial infection through hydrolytic degradation of bacterial membrane phospholipids. In fact, sPLA₂-IIA effectively kills Gram-positive bacteria and to a lesser extent Gram-negative bacteria and is considered a major component of the eye’s innate immune defense system. The antibacterial properties of sPLA₂ have been demonstrated in rabbit and human tears. In this report, we have analyzed the bactericidal activity of dromedary tears and the subsequently purified sPLA₂ on several Gram-positive bacteria. Our results showed that the sPLA₂ displays a potent bactericidal activity against all the tested bacteria particularly against the Staphylococcus strains when tested in the ionic environment of tears. There is a synergic action of the sPLA₂ with lysozyme when added to the bacteria culture prior to sPLA₂. Interestingly, lysozyme purified from dromedary tears showed a significant bactericidal activity against Listeria monocytogene and Staphylococcus epidermidis, whereas the one purified from human tears displayed no activity against these two strains. We have also demonstrated that Ca²⁺ is crucial for the activity of dromedary tear sPLA₂ and to a less extent Mg²⁺ ions. Given the presence of sPLA₂ in tears and intestinal secretions, this enzyme may play a substantial role in innate mucosal and systemic bactericidal defenses against Gram-positive bacteria.     

Nanoscale battery cathode materials induce DNA damage in bacteria

The increasing use of nanoscale lithium nickel manganese cobalt oxide (Li_xNi_yMn_zCo_1−y−zO₂, NMC) as a cathode material in lithium-ion batteries poses risk to the environment. Learning toxicity mechanisms on molecular levels is critical to promote proactive risk assessment of these complex nanomaterials and inform their sustainable development. We focused on DNA damage as a toxicity mechanism and profiled in depth chemical and biological changes linked to DNA damage in two environmentally relevant bacteria upon nano-NMC exposure. DNA damage occurred in both bacteria, characterized by double-strand breakage and increased levels of many putative chemical modifications on bacterial DNA bases related to direct oxidative stress and lipid peroxidation, measured by cutting-edge DNA adductomic techniques. Chemical probes indicated elevated intracellular reactive oxygen species and transition metal ions, in agreement with DNA adductomics and gene expression analysis. By integrating multi-dimensional datasets from chemical and biological measurements, we present rich mechanistic insights on nano-NMC-induced DNA damage in bacteria, providing targets for biomarkers in the risk assessment of reactive materials that may be extrapolated to other nano–bio interactions.

The increasing use of nanoscale lithium nickel manganese cobalt oxide (Li_xNi_yMn_zCo_1−y−zO₂, NMC) as a cathode material in lithium-ion batteries poses risk to the environment. We report DNA damage that occurs in bacteria after nano-NMC exposure with rich chemical details.     

Preparation and characterization of novel polyimide/functionalized ZnO bionanocomposite for gas separation and study of their antibacterial activity

In the present investigation novel Polyimide/functionalized ZnO (PI/ZnO) bionanocomposites containing amino acid (Methionine) and benzimidazole pendent groups with different amounts of modified ZnO nanoparticles (ZnO NPs) were successfully prepared through ultrasonic irradiation technique. Due to the high surface energy and tendency for agglomeration, the surface ZnO NPs was modified by a coupling agent as 3- methacryloxypropyl-trimethoxysilane (MPS) to form MPS-ZnO nanoparticles. The ultrasonic irradiation effectively changes the rheology and the glass transition temperature and the crystallinity of the composite polymer. PI/ZnO nanocomposites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscope (TEM). TEM analysis showed that the modified ZnO nanoparticles were homogeneously dispersed in polymer matrix. The TGA results of PI/ZnO nanocomposites showed that the thermal stability is obviously improved the presence of MPS-ZnO NPs in comparison with the pure PI and that this increase is higher when the NP content increases. The permeabilities of pure H₂, CH₄, O₂, and N₂ gases through prepared membranes were determined at room temperature (25 °C) and 20 bar feed pressure. The membranes having 20% ZnO showed higher values of H₂ permeability, and H₂/CH₄ and H₂/N₂ ideal selectivities (the ratio of pair gas permeabilities) compared with other membranes. The antibacterial activity of bionanocomposite films was tested against gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa). Further, it was observed that antibacterial activity of the resulting hybrid biofilms showed somewhat higher for gram-positive bacteria compared to gram-negative bacteria.