Antibacterial Properties Research Articles

Formulation and characterization of surfactants with antibacterial and corrosion-inhibiting properties for enhancing shale gas drainage and production

A Gemini cationic surfactant was synthesized through an aldehyde-amine condensation reaction to address challenges related to bacterial corrosion and foaming during shale gas extraction. This treatment agent exhibits sterilization, corrosion mitigation, and foaming properties. The mechanism of action was characterized through tests measuring surface tension, particle size, sterilization efficacy, corrosion mitigation efficiency, and foaming behavior. Results from the surface tension test indicate that at 60 °C, surfactants with a low carbon chain structure achieve the lowest surface tension of 32.61 mN/m at the critical micelle concentration. Particle size distribution (PSD) tests reveal that within the 1–10 critical micelle concentration range, three types of surfactants can form aggregates through self-assembly, with a PSD range of 100–400 nm. Antibacterial performance tests demonstrate that a concentration of 0.12 mmol/L at 20–60 °C achieves a bactericidal rate exceeding 99%, maintained even after 24 h of contact. The bactericidal effect is enhanced under acidic and alkaline conditions. Corrosion mitigation tests show that at 50 °C, the corrosion mitigation rate reaches an optimal value of over 70%. Bubble performance evaluation results suggest that the optimal surfactant concentration is 1 mmol/L at 60 °C, exhibiting resistance to mineralization up to 200 g/L. The development of this surfactant establishes a foundation for effectively addressing issues related to bacterial corrosion and wellbore fluid encountered in shale gas wells.

Enhancing elemental release and antibacterial properties of resin-based dental sealants with calcium phosphate, bioactive glass, and polylysine

BackgroundThis study aimed to develop ion-releasing and antibacterial resin-based dental sealants comprising 3 to 6 wt% monocalcium phosphate monohydrate (MCPM, M), 3 to 6 wt% bioactive glass (BAG, B), and 3 to 6 wt% polylysine (PLS, P). The physical properties, mechanical performance, cytotoxicity, and inhibition of S. mutans biofilm by these materials were subsequently evaluated.MethodsFive experimental dental sealants were formulated as follows: F1 (M6B6P6), F2 (M6B6P3), F3 (M3B3P6), F4 (M3B3P3), and F5 (M0B0P0, serving as the control). ClinproXT (CP, 3 M, Saint Paul, MN, USA) was used for commercial comparison. The degree of monomer conversion (DC) was determined using attenuated total reflectance-Fourier transform infrared spectroscopy (n = 5). The biaxial flexural strength (n = 6) and Vickers surface microhardness (n = 5) of the materials were evaluated after a 24-hour immersion in water. The element release over 4 weeks was measured using inductively coupled plasma-optical emission spectrometry (ICP-OES) (n = 3). The cell viability of mouse fibrosarcoma cells exposed to the extract was assessed via an MTT assay (n = 3). Additionally, the inhibition of S. mutans biofilm was tested (n = 3). Statistical analysis was conducted using one-way ANOVA and the Tukey HSD test.ResultsThe lowest DC among experimental sealants was obtained from F1 (66 ± 4%), which was significantly higher than CP (54 ± 2%, p < 0.001). The lowest biaxial flexural strength was obtained from F3 (131 ± 47 MPa). This was comparable to that of CP (140 ± 58 MPa, p = 0.992). The lowest surface microhardness among experimental materials was detected with F2 (19 ± 2 Vickers hardness number), which was higher than that of CP (12 ± 1 Vickers hardness number, p = 0.003). Furthermore, high cell viability of > 90% after exposure to extracts from the experimental materials was detected, which was similar to that observed with CP. Additionally, the experimental materials exhibited higher Ca and P release compared to CP and showed a potential trend for reducing S. mutans biofilm formation. Increasing additive concentrations exhibited minimal effects on material properties, except for enhanced elemental release and a slight reduction in BFM with higher PLS content.ConclusionThe experimental sealants provided sufficient physical and mechanical strength and maintained cell viability and bacterial inhibition with higher elemental release than the commercial product.

Nanocapsuled Neutrophil Extracellular Trap Scavenger Combating Chronic Infectious Bone Destruction Diseases.

Chronic infectious bone destruction diseases, such as periodontitis, pose a significant global health challenge. Repairing the bone loss caused by these chronic infections remains challenging. In addition to pathogen removal, regulating host immunity is imperative. The retention of neutrophil extracellular traps (NETs) in chronic infectious niches is found to be a barrier to inflammation resolution. However, whether ruining the existing NETs within the local infectious bone lesions can contribute to inflammation resolve and bone repair remains understudied. Herein, a nanocapsuled delivery system that scavenges NETs dual-responsively to near-infrared light as a switch and to NETs themselves as a microenvironment sensor is designed. Besides, the photothermal and photodynamic effects endow the nanocapsules with antibacterial properties. Together with the ability to clear NETs, these features facilitate the restoration of the normal host response. The immunocorrective properties and inherent pro-osteogenic effects finally promote local bone repair. Together, the NET scavenging nanocapsules address the challenge of impaired bone repair in chronic infections due to biased host response caused by excessive NETs. This study provides new concepts and strategies for repairing bone destruction attributable to chronic infections via correcting biased host responses in chronic infectious diseases.

In vitro evaluation of the immunomodulatory and antibacterial activities of calcitriol (1,25-dihydroxy-vitamin D3) as a potential application for aerobic vaginitis treatment - preliminary study results

BackgroundAerobic vaginitis (AV) is a state of abnormal vaginal microbiota, which is associated with increased numbers of aerobic, enteric bacteria and inflammation of the vaginal epithelium. Anti-microbial treatment combined with anti-inflammatory therapy could be useful in the treatment of this condition. It is known that calcitriol, the active form of vitamin D, plays an important role in modulating the immune response in several inflammatory diseases. The aim of this preliminary study was to evaluate in vitro the influence of calcitriol on the immune response of human vaginal epithelial cells to bacterial infection. Moreover, we assessed the anti-bacterial properties of calcitriol, as well as its synergistic activity with antibiotics that are used for the treatment of AV.ResultsHuman vaginal A431 epithelial cells were treated with calcitriol (100 nM) and then stimulated with thermally inactivated strains of AV-associated bacteria (Escherichia coli, Enterococcus faecalis, Streptococcus agalactiae), or first stimulated with heat-treated bacteria and then incubated with calcitriol (30 nM). After 24 h, 48 h, and 72 h post-infection, culture supernatants were collected, and levels of pro-inflammatory cytokines IL-6 and IL-1β were analyzed using enzyme-linked immunosorbent assays (ELISA). As it turned out, calcitriol treatment pre- or post-bacterial stimulation of vaginal epithelial cells significantly decreased the levels of IL-6 and IL-1β compared to cells stimulated only with bacteria. Downregulation of pro-inflammatory cytokines was more frequently significant when cells were pre-treated with calcitriol. Additionally, this study evaluated the anti-bacterial properties and synergistic activity of calcitriol with antibiotics by determining the Minimal Inhibitory Concentration (MIC) using colorimetric, Resazurin-based microdilution method detecting the active metabolism of bacteria. As a result, calcitriol by itself did not exhibit clinically relevant anti-bacterial activity; however, when combined with antibiotics, calcitriol significantly reduced the MIC values.ConclusionsThe results of this preliminary study confirm that calcitriol treatment influences cytokine-mediated immune response during infection and indicate that it can be effective in enhancing antibiotic activity. Such properties could be very useful in the treatment of inflammatory diseases. However, conclusions regarding the potential use of calcitriol in the treatment of AV require further confirmation in in vivo studies as well as in well-designed clinical trials.

Single-atom nanozymes with intelligent response to pathological microenvironments for bacterially infected wound healing.

Wound healing is a complex and dynamic process often accompanied by bacterial infection, inflammation, and excessive oxidative stress. Single-atom nanozymes with multi-enzymatic activities show significant potential for promoting the healing of infected wounds by modulating their antibacterial and anti-inflammatory properties in response to the wound's physiological environment. In this study, we synthesized MN4 single-atom nanozymes with multi-enzymatic activities that intelligently respond to pH value changes in the wound healing process. In vitro experiments confirm their effectiveness against Gram-negative bacteria, attributed to elevated reactive oxygen species (ROS) accumulation within the bacterial cells. Moreover, a full-thickness skin wound-infected model demonstrates that MN4 single-atom nanozymes accelerate wound repair and skin regeneration by suppressing the expression of tumor necrosis factor-alpha (TNF-α), promoting angiogenesis, and enhancing collagen deposition. In vivo biocompatibility experiments further demonstrate the favorable biocompatibility of these nanozymes, highlighting their potential for clinical applications in infected wound healing. These nanozymes respond intelligently to different microenvironments and may be suitable for addressing further complex and variable diseases.

Effect of Graphene Oxide on the Antibacterial, Antioxidant, and Optical Properties of Bismuth Oxide and PVA-Based Hydrogel for the Biomedical Sector

Effect of Graphene Oxide on the Antibacterial, Antioxidant, and Optical Properties of Bismuth Oxide and PVA-Based Hydrogel for the Biomedical Sector

Construction of Escherichia coli cell factory for efficient synthesis of indigo.

Indigo is widely used in dyes, medicines and semiconductors materials due to its excellent dyeing efficiency, antibacterial, antiviral, anticancer, anti-corrosion, and thermostability properties. Here, a biosynthetic pathway for indigo was designed, integrating two enzymes (EcTnaA, MaFMO) into a higher L-tryptophan-producing the strain Escherichia coli TRP. However, the lower catalytic activity of MaFMO was a bottleneck for increasing indigo titers. To overcome this limitation, the enzyme activity of MaFMO was enhanced through mechanism-guided rational design. The optimal mutant obtained in this study, MaFMOD197E, whose kcat/Km was 1.34 times that of the wild type, and its specific activity was 2.36 times that of the wild type. In addition, the expression levels of EcTnaA and MaFMOD197E were regulated by optimizing the promoters and increasing the copy number to generate the strain E. coli IND-13. Finally, in the optimal fermentation conditions (220 rpm, 0.05% Tween-80), the strain E. coli IND-13 achieved the indigo titer of 568.52 mg/L in a 5-L bioreactor, with the yield and productivity of 2.62 mg/g and 12.96 mg/L/h (the highest to date), respectively. The results presented here can lay a foundation for further construction of cell factories for indigo and its derivatives with industrial application potential.

Biomimetic Silicone Surfaces for Antibacterial Applications

Biomimetic patterning emerges as a promising antibiotic-free approach to protect medical devices from bacterial adhesion and biofilm formation. The main advantage of this approach lies in its simplicity and scalability for industrial applications. In this study, we employ it to produce antibacterial coatings based on silicone materials, widely used in the healthcare industry. In doing so, we patterned silicone substrates with a topography of various flower petals (rose, chamomile, pansy, and magnolia) and studied the relationship between the antibacterial properties of the obtained biomimetic substrates and their surface topography. To study the surface topography of biomimetic surfaces, we used the fractal analysis of their SEM images. In particular, as a measure of surface complexity and heterogeneity, we used the values of the developed interfacial area ratio (Sdr) and lacunarity coefficient (β). In the result, we found that the bacterial area coverage of biomimetic substrates decreased exponentially with the increase in their surface complexity and heterogeneity, and prominent antibacterial properties were observed at β &gt; 1.6 and Sdr &gt; 50. The results of this study can be used to identify biomimetic materials with superior antibacterial properties and produce efficient antibacterial silicone coatings for biomedical and healthcare applications.

Phytochemical Screening, Antioxidant Test and Antimicrobial Test of Streptococcus Mutans and Candida Albicans from Extracts of Ultrasound Assisted Extraction of Red Betel Leaves (Piper Ornatum N. E. Br)

Red betel (Piper ornatum) is an ornamental plant with potential antibacterial and antioxidant properties due to its bioactive compounds, including alkaloids, flavonoids, steroids, triterpenoids, saponins, and tannins. This study aimed to determine the relationship between flavonoid content, antioxidant activity, and antimicrobial activity in red betel leaves. Ultrasound-Assisted Extraction (UAE) was employed using three solvents of varying polarity: n-hexane (non-polar), ethyl acetate (semi-polar), and ethanol (polar). Total flavonoid content was determined spectrophotometrically based on flavonoids' ability to form complexes with AlCl3. Antioxidant activity was assessed using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Antibacterial and antifungal properties were evaluated through Minimum Inhibitory Concentration (MIC) and Zone of Inhibition (ZOI) tests. MIC was determined using the agar dilution method, while ZOI was measured using the disc diffusion method. Results showed that the 96% ethanol extract yielded the highest flavonoid content (4.748%) and the strongest antioxidant activity (IC50 = 47.185 ppm, classified as very strong). The n-hexane extract at 25% concentration exhibited the best antibacterial activity against Streptococcus mutans (ZOI = 17.43 mm), while the 96% ethanol extract at 25% concentration demonstrated the highest antifungal activity against Candida albicans (ZOI = 17.02 mm). In conclusion, red betel leaf extracts show promising potential as strong antioxidants and antimicrobial agents against C. albicans and S. mutans.

Probing the Active Nitrogen Species in Nitrogen-Doped Carbon Nanozymes for Enhanced Oxidase-Like Activity.

Nitrogen doping emerges as a potent approach to enhance the oxidase-like activity of carbon nanozymes. However, the unclear knowledge of the active nitrogen species within nitrogen-doped carbon nanozymes hinders the advancement of high-performance carbon nanozymes. Herein, a group of nitrogen-doped carbon (N/C) nanozymes with controllable nitrogen dopants are successfully synthesized via a dicyandiamide-assisted pyrolysis method. The intrinsic connection between different nitrogen configurations (pyridinic N, pyrrolic N, and graphitic N) in N/C nanozymes and the oxidase-like performance are experimentally investigated. The results confirm pyridinic N is the active nitrogen species in N/C nanozymes for enhanced oxidase-like activity. Theoretical calculations further reveal the potential regulatory mechanism is pyridinic N can increase the local charge density of neighboring carbon atoms and accelerate the adsorption and activation of molecular oxygen. Notably, the optimized N/C nanozyme with the highest pyridinic N ratio presents impressive oxidase-like performance, surpassing most of the previously reported oxidase-like materials. Moreover, the optimized N/C nanozyme exhibits excellent antibacterial properties and can be easily incorporated into common medical and hygiene products to give them spontaneous antibacterial properties. The work will facilitate the rational design of carbon nanozymes with high-performance oxidase-like activity for applications in the antibacterial field.

Zinc-doped hydroxyapatite loaded chitosan gelatin nanocomposite scaffolds as a promising platform for bone regeneration

The advancement in the arena of bone tissue engineering persuades us to develop novel nanocomposite scaffolds in order to improve antibacterial, osteogenic, and angiogenic properties that show resemblance to natural bone extracellular matrix. Here, we focused on the development of novel zinc-doped hydroxyapatite (ZnHAP) nanoparticles (1, 2 and 3 wt%; size: 50-60 nm) incorporated chitosan-gelatin (CG) nanocomposite scaffold, with an interconnected porous structure. The addition of ZnHAP nanoparticles decreases the pore size (∼30 µm) of the CG scaffolds. It was observed that with the increase in the concentration of ZnHAP nanoparticles (3 wt%) in CG scaffolds, the swelling ratio (1760% ± 2.0%), porosity (71% ± 0.98%) and degradation rate (35%) decreased, whereas mechanical property (1 MPa) increased, which was better as compared to control (CG) samples. Similarly, the high deposition of apatite crystals especially CG-ZnHAP3nanocomposite scaffold revealed the excellent osteoconductive potential among all other scaffolds. MC3T3-E1 osteoblastic cells seeded with CG-ZnHAP nanocomposite scaffolds depicted better cell adhesion, proliferation and differentiation to osteogenic lineages. Finally, the chorioallantoic membrane (CAM) assay revealed better angiogenesis of ZnHAP nanoparticles (3 wt%) loaded CG scaffolds supporting vascularization after 7th day incubation in the CAM area. Overall, the results showed that the CG-ZnHAP3nanocomposite scaffold could be a potential candidate for bone defect repair.

Infrared Ultralow‐Emissivity Polymeric Metafabric Conductors Enabling Remarkable Electromagnetic and Thermal Management

AbstractInfrared ultralow‐emissivity fabric has garnered significant interest for applications in infrared stealth and personal thermal management. However, reconciling the competing demands of low emissivity, breathability, and mechanical strength poses a formidable challenge. Here, an air‐permeable polymeric metafabric distinguished by a unique non‐through‐hole structure is presented. This design is achieved through the electroless plating of silver nanoparticles onto commercially available nylon fabric, supplemented by an intermediate layer of hot‐processed nylon porous mesh. This metafabric demonstrates an ultralow emissivity of 0.044, an exceptional electrical conductivity of 51 315 S m−1, an impressive electromagnetic interference shielding efficiency of 78 dB, and a high tensile strength of 110 MPa. The emissivity, conductivity, and strength of the metafabric are among the highest values reported for infrared low‐emissivity fabrics. The metafabric also exhibits an air permeability that conforms to Grade 2 of international standards. The metafabric facilitates personal precision heating across diverse environments through its integrated capabilities of passive radiative and active solar/Joule heating. Additionally, the metafabric displays antibacterial properties, flame retardancy, sweat absorption, quick‐drying, and washability performance, thereby significantly enhancing its wearability. This high‐performance, multifunctional, infrared ultralow‐emissivity polymeric metafabric holds great promise for applications in infrared camouflage, electromagnetic protection, and personal thermal management.

Phytic Acid-Induced Gradient Hydrogels for Highly Sensitive and Broad Range Pressure Sensing.

Ionic conductive hydrogels have emerged as an excellent option for constructing dielectric layers of interfacial iontronic sensors. Among these, gradient ionic hydrogels, due to the intrinsic gradient elastic modulus, can achieve a wide range of pressure responses. However, the fabrication of gradient hydrogels with optimal mechanical and sensing properties remains a challenge. In this study, it is discovered first that phytic acid (PA) interacts in remarkably distinct manners (i.e., plasticizing effects and phase separation) with different polymers (i.e., polyacrylamide and polyacrylic acid). This distinctive PA-polymer interacting mechanism is innovatively utilized to construct a modulus gradient ionic hydrogel through a simple precursor solution infiltration approach. The gradient hydrogel-based flexible pressure sensor not only achieves a high sensitivity (9.00kPa-1, <15kPa) and a broad sensing range (from ≈3.7Pa to 1.2MPa) simultaneously, but also exhibits superior low pressure sensing performance. It successfully recognizes the subtle pressure due to acoustic waves and airflow, as well as the moderate pressure due to speaking and finger pressing and the high magnitude of plantar pressure. In addition, the gradient hydrogel demonstrates remarkable antibacterial properties and biocompatibility. This functional hydrogel with excellent sensing performance and bioactivity exhibits exceptional potential for wearable sensing applications.

Exploring Antibacterial Properties of Marine Sponge-Derived Natural Compounds: A Systematic Review

The rise in multidrug-resistant (MDR) bacteria has prompted extensive research into antibacterial compounds, as these resistant strains compromise current treatments. This resistance leads to prolonged hospitalization, increased mortality rates, and higher healthcare costs. To address this challenge, the pharmaceutical industry is increasingly exploring natural products, particularly those of marine origin, as promising candidates for antimicrobial drugs. Marine sponges, in particular, are of interest because of their production of secondary metabolites (SM), which serve as chemical defenses against predators and pathogens. These metabolites exhibit a wide range of therapeutic properties, including antibacterial activity. This systematic review examines recent advancements in identifying new sponge-derived compounds with antimicrobial activity, specifically targeting Pseudomonas aeruginosa, a prevalent Gram-negative pathogen with the highest incidence rates in clinical settings. The selection criteria focused on antimicrobial compounds with reported Minimum Inhibitory Concentration (MIC) values. The identified SM include alkaloids, sesterterpenoids, nitrogenous diterpene, and bromotyrosine-derived derivatives. The structural features of the active compounds selected in this review may provide a foundational framework for developing new, highly bioactive antimicrobial agents.

Ordered Interfacial Water Generated at Poly(ionic liquid) Membrane Surface Imparts Ultrafast Water Transport and Superoleophobicity.

Achieving ultrahigh permeance and superoleophobicity is crucial for membrane application. Here, we demonstrated that a poly(ionic liquid)/PES hydrogel membrane can achieve dual goals. The high polarity of the ionic liquids induces the water molecules on the membrane surface to be arranged more ordered, as verified by molecular dynamics (MD) simulation and advanced femtosecond sum frequency generation (SFG) vibrational spectroscopy. Meanwhile, a large amount of water exists in membrane pores, demonstrated by water absorption, low-field nuclear magnetic resonance, and SFG spectroscopy. The interfacial water layer endows the membrane with superior anti-oil-fouling properties, and the large amount of water in membrane pores imparts membrane with ultrahigh permeability. The positive charge on the channel surface and moderate channel size confer a high rejection of metal ions. The optimal membrane exhibited a permeance of 35.1 L m-2 h-1 bar-1, 5-10 times that of conventional hydrogel membranes with similar rejection. Moreover, the membrane exhibited excellent antibacterial properties. It can be expected that highly polar poly(ionic liquid) membranes will find promising applications in the water treatment field.

Indicators of the Microbial Corrosion of Steel Induced by Sulfate-Reducing Bacteria Under the Influence of Certain Drugs

Microorganisms cause microbiologically influenced corrosion, for the prevention of which bactericide inhibitors are used. The aim of the work was to study in vitro the sensitivity of SRB Desulfovibrio oryzae NUChC SRB1 to different concentrations of dimethyl sulfoxide (DMSO), and evaluate the indicators of the microbial corrosion of steel induced by this bacterium in the presence of the pharmaceutical drugs DMSO and paracetamol. The sensitivity of SRB D. oryzae to 1–100% DMSO (v/v) was studied via the dilution method in Postgate’s “C” liquid medium. The corrosion activity of D. oryzae against steel 3 was investigated under DMSO and paracetamol treatment at a final concentration of 45% (v/v) and 0.2% (w/v), respectively, according to the ability of bacteria to form a biofilm on the surface of the steel samples (via the crystal violet method) and the effect on the corrosion rate (via the gravimetric method). It was revealed that DMSO affected D. oryzae NUChC SRB1 and exhibited bactericidal properties (at a concentration range of 10–100%, v/v) and antibiofilm properties (at a concentration of 45%, v/v). Despite its antibiofilm properties confirmed by the reduction in bacterial biofilm mass, anticorrosion features were not observed in the model 35-day conditions of the microbial corrosion of steel in an anaerobic environment with bacterial sulfate reduction. Paracetamol (0.2%, w/v) did not affect biofilm formation by SRB under these conditions, and significantly contributed to an increase in the rate of the microbial corrosion of steel. The prospect of further research is to assess the effect of DMSO and paracetamol on the indicators of microbial corrosion induced by SRB under the influence of the concentrations of these compounds found in wastewater, to clarify the possible additional causes of damage to the equipment of treatment plants. Further research should also be directed at investigating the antimicrobial properties of complexes of compounds with DMSO, which should be considered as an ecological solution to the problem of microbiologically influenced corrosion prevention.

Syzygium aromaticum extract mediated, sustainable silver nanoparticle synergetic with heterocyclic antibiotic clarithromycin and their antimicrobial activities

Microorganisms are becoming resistant to drugs and antimicrobials, making it a significantly critical global issue. Nosocomial infections are resulting in alarmingly increasing rates of morbidity and mortality. Plant derived compounds hold numerous antimicrobial properties, making them a very capable source to counteract resistant microbial strains. Syzygium aromaticum (Clove) extract has been proven by studies to contain active ingredients that demonstrate antibacterial, antifungal, antioxidant, and insecticidal properties. It has also been used historically for its pain relief especially for tooth ache. Clove extract derived nanoparticle synthesis is a promising method of combining therapeutics with metals at nanoscale. Such nanostructured systems in combination with the heterocyclic antibiotic clarithromycin could potentiate the action of plant extracts, decrease drug side effects and improve antimicrobial activity. In this study, clove extract (C) was successfully used to synthesize silver nanoparticles (AgNP) to create AgNPC and AgNPCA (A = clarithromycin). The two compounds underwent different analytical methods consisting of SEM, EDS, DLS, UV-vis, FTIR and XRD. These nanoparticles were used against a variety of 10 pathogens and exhibited very good to intermediate antibacterial properties. AgNPC resulted in better antibacterial properties and smaller nanoparticle size. This study demonstrates the potential of clove extract mediated AgNP synthesis in combination with and without the antibiotic clarithromycin.

Fabrication and characterization of 3D-printed polymeric-based scaffold coated with bioceramic and naringin for a potential use in dental pulp regeneration (in vitro study).

3D-printed scaffolds loaded with healing directed agents could be employed for better treatment outcome in regenerative dentistry. The aim of this study was to fabricate and characterize simple 3D-printed poly lactic acid (PLA) scaffolds coated with nanoHydroxyapatite (nHA), Naringin (NAR), or their combination, and testing their morphological, chemical, mechanical, antibacterial, biocompatible and bioactive properties. Two variants pore sizes, 300 and 700 μm, of 3D-printed PLA disc scaffolds measuring (10 × 1 mm) were fabricated. These scaffolds were dip-coated with nHA, NAR, or both (nHA/NAR). Field emission scanning electron microscopy (FeSEM), energy-dispersive X-ray spectroscopy (EDX), Fourier transforms infrared (FTIR), compressive and flexural strength testing was employed for optimizing pore size. Then, antibacterial activity against isolated Streptococcus mutans and Enterococcus faecalis, and cytotoxicity against normal human fibroblast were assessed. Additionally, appetite formation on scaffold surfaces was assessed after storage in simulated body fluid (SBF) for 14 days by further using FeSEM, EDX and XRD. FeSEM showed uniform structure for 3D-printed scaffolds in both pore size designs, and a consistent surface coating with nHA and NAR, which were further confirmed by EDX and FTIR. However, mechanical testing revealed statistical significant higher compressive and flexural strengths (p < .000) for 300 μm pore size scaffolds. Statistical significant antibacterial activities (p < .05) were also found with PLA/NAR, and PLA/nHA /NAR scaffolds in comparison with neat. The MTT assay revealed biocompatibility of PLA, nHA and NAR, with the combinations of the latter two working synergistically. Lastly, the formation of a calcium-phosphate appetite layer was recognized on the surface of PLA/nHA, PLA/nHA/NAR scaffold after being stored in SBF. 3D-printed, 300 μm pore size, PLA scaffold coated with a combination of nHA and NAR showed the best surface characteristics and improved mechanical, antibacterial and biocompatible properties for further investigation in regenerative studies.

DETERMINATION OF TANNIN CONTENT AND ANTIBACTERIAL ACTIVITY OF CHROMOLAENA ODORATA L.

Aims and objectives: To ascertain the antibacterial capability using TLC-bioautography and the tannin content using the UV-Vis spectrophotometric method in the ethanol extract of kopasanda (Chromolaena odorata L.) leaves. Methods: Tannins quantitatively utilizing the UV-Vis spectrophotometric technique using the folin ciocalteu reagent at a wavelength of up to 687 nm. Antibacterial potential against gastrointestinal infection-causing bacteria (Salmonella typhi, Vibrio cholerae, Escherichia coli, and Shigella dysentriae) is assessed using TLC-bioautography technique. Results: The tannin content of the ethanol extract of kopasanda leaves (Chromolaena odorata L.) is 41.9064±0.26 mgTAE/g extract. Escherichia coli, Shigella dysentriae, Salmonella typhi, and Vibrio cholerae, respectively, create inhibitory zones in the antibacterial potential test that yields 7, 8, 8, and 7 stains. Tannins, flavonoids, alkaloids, and saponins are believed to be among the chemicals found in the TLC results obtained with stain spraying reagents 1, 3, 5, and 4, respectively. Conclusions: The average tannin concentration of the ethanol extract of kopasanda leaves (Chromolaena odorata L.) is 41.9064±0.26 mgTAE/g extract, and it has antibacterial properties against germs that cause gastrointestinal illnesses. Peer Review History: Received 22 September 2024; Reviewed 3 November; Accepted 15 December; Available online 15 January 2025 Academic Editor: Dr. Amany Mohamed Alboghdadly, Ibn Sina National College for Medical Studies in Jeddah, Saudi Arabia, amanyalboghdadly@gmail.com Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10

Acetylated cashew gum polysaccharide nanoparticles as a promising green label nanomaterial for encapsulation of D-limonene: physicochemical, structural and antibacterial properties

Acetylated cashew gum polysaccharide nanoparticles as a promising green label nanomaterial for encapsulation of D-limonene: physicochemical, structural and antibacterial properties