Fig 6 - uploaded by Mandana Dilamian
Content may be subject to copyright.
Bacterial growth inhibition by modified Kirby-Bauer disc method. Scaffold were incubated at 37 ◦ C for 24 h on agar plates cultured with Staphylococcus aureus (left panel) and E. coli (right panel). chitosan/PEO nanofiber (weight ratio of 75:25) (a) control sample without, (b) 0.5 mM PHMB and (c) with 1 mM PHMB.
Contexts in source publication
Context 1
... disks absorb water from the agar medium and the release of the antimicrobial is initiated and PHMB migrates through the adjacent agar medium. As a result, a gradually changing gradient of the antibacterial concentration develops in the agar surrounding the disk. No clear zone was observed between the control sample and the bacterial colonies (Fig. 6(a)). Zone of inhibition for the sample contained 0.5 mM PHMB were 13.8 mm and 12 mm for S. aureus and E. coli, respectively (Fig. 6(b)). By increasing the PHMB content to 1 mM, the growth inhibition zone diameter increased to 22 mm and 21.1 mm for S. aureus and E. coli, respectively (Fig. 6(c)). Thus, the novel chitosan/PEO/PHMB ...
Context 2
... agar medium. As a result, a gradually changing gradient of the antibacterial concentration develops in the agar surrounding the disk. No clear zone was observed between the control sample and the bacterial colonies (Fig. 6(a)). Zone of inhibition for the sample contained 0.5 mM PHMB were 13.8 mm and 12 mm for S. aureus and E. coli, respectively (Fig. 6(b)). By increasing the PHMB content to 1 mM, the growth inhibition zone diameter increased to 22 mm and 21.1 mm for S. aureus and E. coli, respectively (Fig. 6(c)). Thus, the novel chitosan/PEO/PHMB nanocomposite exhibited an excellent antibacterial ...
Context 3
... between the control sample and the bacterial colonies (Fig. 6(a)). Zone of inhibition for the sample contained 0.5 mM PHMB were 13.8 mm and 12 mm for S. aureus and E. coli, respectively (Fig. 6(b)). By increasing the PHMB content to 1 mM, the growth inhibition zone diameter increased to 22 mm and 21.1 mm for S. aureus and E. coli, respectively (Fig. 6(c)). Thus, the novel chitosan/PEO/PHMB nanocomposite exhibited an excellent antibacterial ...
Citations
... Chitosan has been recognized as an antimicrobial agent, however its ability to act in this way is not completely elucidated as several different mechanisms have been attributed to this nature of chitosan (26,27) . One theory suggests that when exposed to bacterial cell wall, chitosan promotes displacement of Ca++ of an ionic site of the membrane, resulting in cellular destruction (28) . ...
... Antibacterial properties of the membrane were conducted using gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Esteriscia coli) (Supplied by Microbiology laboratory, UM) according to agar disk diffusion methods [48]. The samples were sliced into small circular pieces measuring 5 mm in diameter. ...
Bacterial cellulose (BC) is a natural substance produced by microorganisms and offers numerous benefits. It can be produced by utilizing biomass waste which is abundantly available through fermentation process. This study investigates the utilization of pineapple peel waste for BC synthesis and observes their properties as nanocomposite membranes after the addition of ZnO nanoparticles (ZnO-NPs) as candidate biomaterials for water filtration membranes. The experimental methods were conducted by synthesizing BC using pineapple peel extract using fermentation process. Subsequently, BNC was produced using a high-pressure homogenizer, and ZnO-NPs nanoparticles were added as reinforcement at concentrations of 2.5 wt%, 5.0 wt%, and 7.5wt.%. The mixture was sonicated and subsequently dried in an oven at 60°C for 20 h. BNC/ZnO-NPs membranes were characterized using XRD, FTIR, tensile test, BET, antibacterial test, and SEM analysis. The results indicate that the membrane structure of BNC/ZnO-NPs nanocomposite has peaks at diffraction angles of 14.4°, 15.2°, 16.9°, 22.8°, 31.6°, 34.1° and 36.8°. The addition of ZnO-NPs enhances the crystalline index of BNC by 81.37% at 2.5wt.% ZnO-NPs but reduces the membrane strength due to increasing pore diameter and rougher surface morphology of membrane. Incorporation of ZnO-NPs results in membrane chemical bonding, proved by raising a new peak at wavenumber of 715 cm− 1 and reduces the transmittance of hydroxyl group. This showed antibacterial activity against gram-positive bacteria like S.aureus, but they have no effect on gram-negative bacteria like E. coli. This antibacterial activity is good for resisting biofouling and the membrane can be further developed to meet the requirements for field water filtration applications like desalination.
Graphical Abstract
... This may make it more challenging to load PHMB into polymeric matrices by soaking, as well as its release, in comparison to the typical drugs used. Although a few CS-based hydrogels that release PHMB aimed to be used in AMDs have been reported in the literature [45][46][47][48][49][50][51][52][53][54], PHMB-releasing, CS-based AMDs are not yet Although a few CS-based hydrogels that release PHMB aimed to be used in AMDs have been reported in the literature [45][46][47][48][49][50][51][52][53][54], PHMB-releasing, CS-based AMDs are not yet commercially available [43]. In this work, a contribution to the development of antimicrobial PHMB-based membranes made of CS, aimed at an application as AMDs, is presented. ...
... This is beneficial as it eliminates the possibility of biocompatibility issues or PHMB quantification errors caused by leaching of additional reagents. Comparable CS-based, PHMB-releasing membranes for AMDs required other polymers in addition to CS, such as PEO [45], alginate [46] or PVA [50], crosslinkers [45,54] or surfactants [46]. Some physicochemical characteristics of the resulting membranes, such as morphology, swelling capacity, wettability, water penetration, moisture vapor transmission and the PHMB release kinetics were evaluated, as well as their antimicrobial activity and in vitro blood clotting activity. ...
... This is beneficial as it eliminates the possibility of biocompatibility issues or PHMB quantification errors caused by leaching of additional reagents. Comparable CS-based, PHMB-releasing membranes for AMDs required other polymers in addition to CS, such as PEO [45], alginate [46] or PVA [50], crosslinkers [45,54] or surfactants [46]. Some physicochemical characteristics of the resulting membranes, such as morphology, swelling capacity, wettability, water penetration, moisture vapor transmission and the PHMB release kinetics were evaluated, as well as their antimicrobial activity and in vitro blood clotting activity. ...
Wound infection is a common complication of chronic wounds. It can impair healing, which may not occur without external help. Antimicrobial dressings (AMDs) are a type of external help to infected chronic wounds. In this study, highly porous membranes made of only chitosan and containing the antiseptic polyhexanide (poly(hexamethylene biguanide); PHMB) were prepared by cryogelation, aiming to be used in AMDs. These membranes exhibited a water swelling capacity of 748%, a water drop penetration time of 11 s in a dry membrane and a water vapor transmission rate of 34,400 g H2O/m2/24 h when in contact with water. The best drug loading method involved simultaneous loading by soaking in a PHMB solution and sterilization by autoclaving, resulting in sterilized, drug-loaded membranes. When these membranes and a commercial PHMB-releasing AMD were assayed under the same conditions, albeit far from the in vivo conditions, their drug release kinetics were comparable, releasing PHMB for ca. 6 and 4 h, respectively. These membranes exhibited high antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, which are bacterial species commonly found in infected wounds and blood clotting activity. The obtained results suggest that these membranes may have potential for use in the development of AMDs.
... Antibacterial properties of the membrane were conducted using gram-positive bacteria (Staphylococcus aureus) and gram-negative bacteria (Esteriscia coli) (Supplied by Microbiology laboratory, UM) according to agar disk diffusion methods [24]. The samples were sliced into small circular pieces measuring 5 mm in diameter. ...
Bacterial cellulose (BC) is a natural substance produced by microorganisms and offers numerous benefits. It can be produced by utilizing biomass waste which is abundantly available through the fermentation process. This study investigates the utilization of pineapple peel waste for bacterial cellulose synthesis and observes their properties as nanocomposites membrane after the addition of ZnO nanoparticles (ZnO-NPs). The experimental methods were conducted by synthesizing BC using pineapple peel extract using fermentation process. Subsequently, BNC was synthesized using a high-pressure homogenizer, and ZnO-NPs nanoparticles were added as reinforcement at concentrations of 2.5 wt.%, 5.0 wt.%, and 7.5wt.%. The mixture was sonicated and subsequently dried in an oven at 60°C for 20 h. BNC/ZnO-NPs membranes were characterized using XRD, FTIR, tensile test, BET, antibacterial test, and SEM analysis. The results indicate that the membrane structure of BNC/ZnO-NPs nanocomposite has peaks at diffraction angles of 14.4°, 15.2°, 16.9°, 22.8°, 31.6°, 34.1°, and 36.8°. The addition of ZnO-NPs affects the crystallite size and pore diameter of the membrane. It enhances the crystalline index of BNC by 81.37% at 2.5wt.% ZnO-NPs but reduces the membrane strength. The surface morphology of nanocomposite shows agglomeration with increasing ZnO-NPs content. Membrane BNC/ZnO-NPs show antibacterial activity against S.aureus .
... This may make it more challenging to load PHMB into polymeric matrices by soaking, as well as its release, in comparison to the typical drugs used. Although a few CS-based hydrogels that release PHMB aimed to be used in AMDs have been reported in the literature [44][45][46][47][48][49][50][51][52], PHMB-releasing, CS-based AMDs are not yet commercially available [42]. ...
Wound infection is a common complication of chronic wounds. It can impair healing, which may not occur without external help. Antimicrobial dressings (AMDs) are a type of external help to infected chronic wounds. In this study, highly porous membranes made of only chitosan and containing the antiseptic polyhexanide (poly(hexamethylene biguanide); PHMB) were prepared by cryogelation, aiming to be used in AMDs. These membranes exhibited high water swelling capacity, fast water absorption and high water vapor transmission. The best drug loading method involved simultaneous loading by soaking in a PHMB solution and sterilization by autoclaving, resulting in sterilized, drug-loaded membranes. The drug release kinetics was comparable to that of a commercial PHMB-releasing AMD assayed under the same conditions. These membranes exhibited high antibacterial activity against Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa, which are bacterial species commonly found in infected wounds, and blood clotting activity. The obtained results suggest that these membranes may be suitable for use in the development of AMDs.
... To enhance compatibility and its properties, these reactive groups can be easily chemically derivatized under benign circumstances. Quaternized chitosan, for example, has the potential to be a mucoadhesive and permeability-enhancing absorption enhancer across the intestinal epithelium [35,36]. Cyclodextrin-linked chitosan sounds promising from the perspective of pharmaceutics, which covers drug delivery, aesthetics, and analytical chemistry [33]. ...
... The antibacterial and anti-biofilm actions of chitosan, as well as its solubility and viscosity, are significantly influenced by the above-mentioned factors. [34][35][36]. One idea holds that it destroys cells by pushing Ca++ out of the anionic sites in the membrane [37]. ...
... The active groups in chitosan's chemical structure are amino groups and hydroxyl groups at the C 3 and C 6 locations. Because of the free rotation, the NH 2 -amino group is typically more reactive than the C 6 -OH main hydroxyl group, with the secondary C 3 -OH hydroxyl group being less reactive than the primary hydroxyl group [36][37][38][39][40]. Chitosan can be chemically modified on the amino, hydroxyl, or both amino and hydroxyl groups to create derivatives that are N-, O-, or N, O-modified. ...
Biopolymers are organic polymers that can be treated into intricate designs with porous characteristics that mimic essential biologic components. Due to their superior biosafety, biodegradability, biocompatibility, etc., they have been utilized immensely in biomedical engineering, regeneration, and drug delivery. To obtain the greatest number of results, a literature search was undertaken in scientific search engines utilizing keywords. Chitosan is used in a variety of medical sectors, with the goal of emphasizing its applications and benefits in the clinical dental industry. Chitosan can be dissolved in liquid form and combined with other substances to create a variety of products, including fibers, hydrogels, membranes, microspheres, resins, sponges, pastes, tablets, and micro granules. Chitosan has been studied in a variety of dental applications. Chitosan is used in the prevention of caries and wear, in pulpotomy to accelerate osteogenesis in guided tissue regeneration due to its hemostatic property, and primarily to benefit from its antimicrobial activity by adding it to materials, such as glass ionomer cement, calcium hydroxide, and adhesive systems. With its antibacterial activity and biocompatibility, chitosan is leading the pack as a promising ingredient in the production of dental materials. The current review provides an update on the background, fundamentals, and wide range of uses of chitosan and its gels in dental science.
... The characteristic peaks of PEO overlapped with those in CS and disappeared. 29,30 The peak around 1607 cm −1 is assigned to the N-H deformation of amine groups represented in the CS powder spectrum. This peak is related to the Glucosamine functional group that might have overlapped with the peak near 1660-1610 cm −1 , which belongs to C=O is stretching of amide (I) in N-acetylglucosamine structure. ...
This study aims to evaluate the Vancomycin (VCM) combination with Chitosan (CS)/ Polyethylene oxide (PEO) nanofibers’ intrinsic antibacterial properties causing a synergistic effect against possible serious bacterial infections (PSBI). VCM/CS nanofiber scaffold was fabricated using the electrospinning method. Characterizations are performed by Fourier transform infrared (FT-IR) to examine the functional groups of each compound, scanning electron microscopy (SEM), and transient electron microscopy (TEM) to evaluate nanofiber diameter and structure. Antibacterial activities of the nanofibrous scaffold were assessed against bacterial strains, including standard Staphylococcus aureus ( S. aureus), VCM-sensitive Enterococcus (VSE), methicillin-resistant S. aureus (MRSA), VCM-resistant Enterococcus (VRE), and Streptococcus group A by microdilution broth methods. The FT-IR, SEM, and TEM examination results confirm the CS/PEO nanofiber scaffold fabrication. The antibacterial examination results showed no significant difference between the minimum inhibitory concentration (MIC) values of VCM and with MIC of VCM/CS nanofibers. Still, there were significant differences between the MIC of CS and VCM/CS nanofibers in S. aureus, but this is not more significant than VCM. This study illustrated that VCM coupled to CS nanofibers had acceptable antibacterial activity against the Gram-positive bacterium. This work motivated researchers’ insight into nanostructures’ potential accompanied by antibacterial polymer and antibiotics synergistic effects against PSBI.
... It is hypothesized that chitosan increases the movement of Ca++ from anionic sites of the bacterial cell membranes, which causes cell damage. It also prevents plaque against Porphyromonomas gingivalis, Prevotella intermedia, and Actinobacillus actinomycetemcomitans [137,138]. While generally harmless to mammals, chitosan possesses a broad spectrum of action against gram-negative and gram-positive bacteria. ...
Chitin, which may be the second-most common polymer after cellulose, is the raw material of chitosan. Chitosan has been infused with various plant extracts and subsidiary polymers to improve its biological and physiological properties. Chitosan's physicochemical properties are enhanced by blending, making them potential candidates that can be utilized in multifunctional areas, including food processing, nutraceuticals, food quality monitoring, food packaging, and storage. Chitosan-based biomaterials are biocompatible, biodegradable, low toxic, mucoadhesive, and regulate chemical release. Therefore, they are used in the biomedical field. The present manuscript highlights the application of chitosan-based composites in the food and biomedical industries.
... Among them, Vega-Lugo et al. [15] reported that the viscosity of the electrospinning solution was increased when PEO was added to whey protein isolate, and bead-free NFs were obtained from the higher viscosity and lower surface tension under acidic conditions. Moreover, Dilamian et al. [21] prepared chitosan/ PEO NFs in combination with poly (hexamethylene biguanide) hydrochloride (PHMB), and promising antibacterial activities of the composite NFs against Escherichia coli (E.coli) and Staphylococcus aureus (S. aureus) were observed, suggesting the potential application of PEO with other antimicrobial substances in the fabrication of biomaterials. ...
Electrospinning nanofibers (NFs) made from natural proteins have drawn increasing attention recently. Rapeseed meal is a by-product that rich in protein but not fully utilized due to poor properties. Therefore, modification of rapeseed protein isolates (RPI) is necessary to expand applications. In this study, pH shift alone or ultrasonic-assisted pH shift treatment was adopted, the solubility of RPI, along with the conductivity and viscosity of the electrospinning solution were detected. Moreover, the microstructure and functional characteristics of the electrospinning NFs, as well as the antibacterial activity of clove essential oil loaded-NFs were investigated. The tested parameters were remarkably improved after different treatments compared with the control, and synergistic effects were observed, especially under alkaline conditions. Hence, pH12.5 + US showed the maximum value of solubility, conductivity, and viscosity, which was more than 7-fold, 3-fold, and almost 1-fold higher than the control respectively. Additionally, SEM and AFM images showed a finer and smoother surface of NFs after treatments, and the finest diameter of 216.7 nm was obtained after pH12.5 + US treatment in comparison with 450.0 nm in control. FTIR spectroscopy of NFs demonstrated spatial structure changes of RPI, and improved thermal stability and mechanical strength of NFs were achieved after different treatments. Furthermore, an inhibition zone with a diameter of 22.8 mm was observed from the composite NFs. This study indicated the effectiveness of ultrasonic-assisted pH shift treatment on the physicochemical properties improvement and functional enhancement of NFs made from RPI, as well as the potential antibacterial application of the composite NFs in the future.
... Owing to the low stability and high viscosity of chitosan solutions, it is also common to employ blending polymers to improve the processability of electrospun nanofibers. The compatibly used blending polymers could be polyurethane (PU), polyvinyl alcohol (PVA), and polyethylene (PEO), etc. [97]. For example, Wang et al. [98] used PVA to blend with quaternized chitosan for the development of composite electrospun nanofiber (in Figure 5d). ...
Aerosol particles, such as the widespread COVID-19 recently, have posed a great threat to humans. Combat experience has proven that masks can protect against viruses; however, the epidemic in recent years has caused serious environmental pollution from plastic medical supplies, especially masks. Degradable filters are promising candidates to alleviate this problem. Degradable nanofiber filters, which are developed by the electrospinning technique, can achieve superior filtration performance. This review focuses on the basic introduction to air filtration, the general aspects of face masks, and nanofibers. Furthermore, the progress of the state of art degradable electrospun nanofiber filters have been summarized, such as silk fibroin (SF), polylactic acid (PLA), chitosan, cellulose, and zein. Finally, the challenges and future development are highlighted.
