Hemolysis Test Research Articles

Evaluation of the double-zone hemolysis (DZH) test for the detection of livestock-associated methicillin-resistant Staphylococcus aureus.

This study evaluated a simple and reliable phenotypic test that can be very useful in the clinical microbiology laboratory to detect livestock-associated (LA) methicillin-resistant Staphylococcus aureus (MRSA) isolates and S. aureus of potential animal origin. The proposed double-zone hemolysis test has shown high positive and negative predictive values, sensitivity, and specificity to detect these LA-MRSA clones and S. aureus of potential animal origin. Most LA-MRSA clones exhibit resistance to different classes of antibiotics, with unique epidemiological characteristics, and their early detection has public health relevance and patient management.

Methodological optimization for efficient degradation of Acid Violet 49 using advanced oxidation processes and varied photocatalyst combinations

This study investigates the photodegradation of Acid Violet 49 in an aqueous medium under UV, UV/H2O2, and combined with photo catalyst (UV/H2O2/TiO2, UV/H2O2/ZnO, and UV/H2O2/SnO2). The impact of all operational parameters including catalytic dosage, peroxidation (H2O2), pH and dye concentration were evaluated. The degradation efficiency of AV49 was enhanced up to 96% with the alternative photocatalyst UV/H2O2/ZnO under the circumstances of 0.6mL H2O2, 0.9 g ZnO, 50 mg/L initial dye concentration, and pH 9 after 90 min. Hemolytic test were used to check the toxicity level of products. FTIR spectroscopy of UV/ZnO/H2O2 was applied to identify the functional group of AV49 before and end product of the degradation. Moreover, the analytical technique LC-MS provided valuable information regarding the degradation products of AV 49. A proposed pathway was identified based on the findings of the degradation product.

Novel ionic chitosan derivatives based on pyridinium sulfonate: Synthesis, characterization, and studies on antimicrobial, antioxidant, and biocompatibility properties.

To improve the solubility, antimicrobial efficacy, antioxidant capacity, and biocompatibility of chitosan for broader applications, a series of novel ionic chitosan derivatives were synthesized in this study by amidating chitosan with carboxyl pyridinium sulfonate. These derivatives were characterized through various analytical techniques, including FTIR, 1H NMR, UV, TGA, and XRD. Proton NMR was particularly utilized to determine the degree of substitution. The modified chitosans showed improved water solubility. Their antimicrobial activity against gram negative E. coli and gram positive S. aureus was evaluated in vitro through inhibition rates, minimum inhibitory concentrations (MIC), and minimum bactericidal concentrations (MBC), demonstrating high effectiveness at low concentrations. Additionally, antioxidant tests indicated that these derivatives possess significantly greater antioxidant activities compared to original chitosan, particularly the 5OHNASCS derivative which showed exceptional radical scavenging and reducing capabilities. Furthermore, the CCK-8 assay was employed to assess cytotoxicity in 293T cells (human embryonic kidney cells), with all samples exhibiting no toxicity. Hemolysis tests were also conducted, revealing that the newly synthesized series of ionic chitosan derivatives showed no hemolytic activity, indicating good biocompatibility and potential for application as wound dressings. In summary, these newly developed ionic chitosan derivatives demonstrated excellent water solubility, antimicrobial activity, antioxidant capacity, and biocompatibility, suggesting their potential use in food and biomedical materials.

Rapid release of high-valent silver ions from water-soluble porphyrin complexes to enhance the direct killing of Methicillin-Resistant Staphylococcus aureus

The emergence of multidrug-resistant (MDR) bacteria represented by MRSA (Methicillin-resistant Staphylococcus aureus) poses a great challenge to current anti-infection treatment. It is critical to develop efficient MRSA anti-bacteria drugs and explore simple therapeutic strategies with low MDR risk. Herein, we synthesized high-valent (AgII/AgIII) water-soluble porphyrins (cationic AgTMPyP and anionic AgTMPPS) and investigated their direct bactericidal property for MRSA without photoactivation in vitro and in vivo. The cationic porphyrin AgTMPyP exhibits well oxidase-like activity and has 100% sterilizing rate at 8 μmol/L concentration. Besides, AgTMPyP can effectively destroy biofilms in vitro, mediate the polarization of macrophages from M1 to M2, and promote wound healing in vivo. Combined with DFT calculation, the related antibacterial mechanism is further discussed. High-valent silverporphyrins can maintain stable in water for at least 200 days. The moment they encounter MRSA, high-valent silver ions from AgTMPyP can be immediately released from the porphyrin ring and attack the MRSA with efficient sterilization. Together with the hemolysis, blood routine and blood biochemistry tests, it is proved that AgTMPyP can have great prospects in the direct treatment of bacterial infections in skin diseases in the future. Statement of significance: The emergence of multidrug-resistant (MDR) bacteria represented by MRSA poses a great challenge to current anti-infection treatment. It has become critical to develop efficient MRSA anti-bacteria drugs and explore simple therapeutic strategies with low MDR risk. We synthesized high-valent (AgII/AgIII) water-soluble silver porphyrins (AgTMPyP and AgTMPPS), which can be stable for long periods in aqueous solutions. AgTMPyP can directly and efficiently kill bacteria and destroy biofilms without photoactivation in vitro and in vivo. Combined with DFT calculation, the related antibacterial mechanism is further discussed. AgTMPyP is a superior antimicrobial agent with good biocompatibility and it can have great prospects in the direct treatment of bacterial infections and wound healing in the future.

Analysis on Evaluation Method of Mechanically-Induced Hemolysis of Medical Devices

Mechanically-induced hemolysis is an important index for evaluating the blood compatibility of medical devices. It mainly evaluates the risk of mechanical hemolysis under simulated clinical use conditions of medical devices. The existing hemolysis test standards mainly evaluate the risk of material-induced hemolysis and cannot evaluate the risk of mechanically-induced hemolysis. Although some institutions have conducted research on mechanically-induced hemolysis caused by medical devices, systematic evaluation standards have not yet been established. This study mainly summarizes the evaluation process, selection of evaluation models, and steps for assessing mechanically-induced hemolysis, providing a reference for relevant evaluations and standard establishment.

PH-sensitive zinc oxide nanoparticle-controlled sodium alginate/silica hydrogel beads: For controlled curcumin release

This study designed a pH-sensitive carrier regulated by zinc oxide nanoparticles for the delivery of the hydrophobic drug curcumin (Cur). Carboxymethyl cellulose (CMC) was used as a stabilizer and dispersant to synthesize CMC-ZnO nanoparticles via an in situ reaction. These nanoparticles were then mixed with sodium alginate (SA) and immersed in a tetraethyl silicate (TEOS) hydrolysis solution to form sodium alginate/silica-zinc oxide (Ss/CMC-ZnO) composite hydrogel beads. XRD, FTIR, SEM, and UV-vis analyses confirmed the successful synthesis and incorporation of ZnO nanoparticles into the hydrogel beads. Swelling experiments demonstrated that as the concentration of CMC-ZnO increased, when the TEOS molar concentration was 0.205 M, the maximum swelling ratio decreased from 39.83 to 14.03, with the time to reach the maximum swelling ratio extending from 4 to 6 hours. At a TEOS concentration of 0.375 M, the swelling ratio decreased from 26.77 to 12.10, with the swelling time extending from 6 to 7 hours. Hemolysis and cytotoxicity tests confirmed the hydrogel beads' good biocompatibility. Cur was incorporated using a blending method, and in vitro release experiments revealed that the Ss/CMC-ZnO hydrogel beads exhibited excellent pH sensitivity. The addition of CMC-ZnO NPs effectively prolonged the release time of curcumin, indicating potential for applications in controlled drug delivery.

Degradation of synthetic reactive Pyrazole-133 dye by using an advanced oxidation process assisted by gamma radiations

This study investigated the degradation of the reactive dye RP-133 in aqueous solution using various hydrogen peroxide concentrations and gamma radiation doses (1–20 kGy). The solution's initial dye concentration and pH were optimized for the most effective degradation efficiency. The dye was treated with H2O2 and gamma radiation separately. At an acidic pH, an absorbed dose of 20 kGy, and 0.9 mL of H2O2, a 95% decomposition rate was achieved. FTIR analysis revealed differences in the functional groups of treated and untreated dye. Intermediates formed during degradation were identified using GC-MS. Hemolytic and Ames tests assessed the cytotoxicity and mutagenicity of the dye. Gamma radiation treatment significantly reduced both mutagenicity and cytotoxicity. Cytotoxicity decreased from 15.1% to 7.6%, and mutagenicity of bacterial strains TA98 and TA100 was reduced by 81.3% and 82.3%, respectively. The formation of low-molecular-weight organic acids further oxidized to carbon dioxide and water, indicating the efficiency of the advanced oxidation process. Combining gamma radiation with H2O2 effectively degraded RP-133, reducing its cytotoxicity and mutagenicity.

Insights into an indolicidin-derived low-toxic anti-microbial peptide's efficacy against bacterial cells while preserving eukaryotic cell viability.

Antimicrobial peptides (AMPs) are a current solution to combat antibiotic resistance, but they have limitations, including their expensive production process and the induction of cytotoxic effects. We have developed novel AMP candidate (peptide 3.1) based on indolicidin, among the shortest naturally occurring AMP. The antimicrobial activity of this peptide is demonstrated by the minimum inhibitory concentration, while the hemolysis tests and MTT assay indicate its low cytotoxicity. In optical diffraction tomography, red blood cells treated with peptide 3.1 showed no discernible effects, in contrast to indolicidin. However, peptide 3.1 did induce cell lysis in E. coli, leading to a reduced potential for the development of antibiotic resistance. To investigate the mechanism underlying membrane selectivity, the structure of peptide 3.1 was analyzed using nuclear magnetic resonance spectroscopy and molecular dynamics simulations. Peptide 3.1 is structured with an increased distinction between hydrophobic and charged residues and remained in close proximity to the eukaryotic membrane. On the other hand, peptide 3.1 exhibited a disordered conformation when approaching the prokaryotic membrane, similar to indolicidin, leading to its penetration into the membrane. Consequently, it appears that the amphipathicity and structural rigidity of peptide 3.1 contribute to its membrane selectivity. In conclusion, this study may lead to the development of Peptide 3.1, a promising commercial candidate based on its low cost to produce and low cytotoxicity. We have also shed light on the mechanism of action of AMP, which exhibits selective toxicity to bacteria while not damaging eukaryotic cells.

Future-Oriented Nanosystems Composed of Polyamidoamine Dendrimer and Biodegradable Polymers as an Anticancer Drug Carrier for Potential Targeted Treatment.

Background/Objectives: Camptothecin (CPT) is a well-known chemical compound recognized for its significant anticancer properties. However, its clinical application remains limited due to challenges related to CPT's high hydrophobicity and the instability of its active form. To address these difficulties, our research focused on the development of four novel nanoparticulate systems intended for either oral or intravenous administration. Methods: These nanosystems were based on a poly(amidoamine) (PAMAM) dendrimer/CPT complex, which had been coated with biodegradable homo- and copolymers, designed with appropriate physicochemical properties and chain microstructures. Results: The resulting nanomaterials, with diameters ranging from 110 to 406 nm and dispersity values between 0.10 and 0.67, exhibited a positive surface charge and were synthesized using biodegradable poly(L-lactide) (PLLA), poly(L-lactide-co-ε-caprolactone) (PLACL), and poly(glycolide-co-ε-caprolactone) (PGACL). Biological assessments, including cell viability and hemolysis tests, indicated that all polymers demonstrated less than 5% hemolysis, confirming their hemocompatibility for potential intravenous use. Furthermore, fibroblasts exposed to these matrices showed concentration-dependent viability. The entrapment efficiency (EE) of CPT reached up to 27%, with drug loading (DL) values as high as 17%. The in vitro drug release studies lasted over 400 h with the use of phosphate buffer solutions at two different pH levels, demonstrating that time-dependent processes allowed for a gradual and controlled release of CPT from the developed nanosystems. The release kinetics of the active compound at pH 7.4 ± 0.05 and 6.5 ± 0.05 followed near-first-order or first-order models, with diffusion and Fickian/non-Fickian transport mechanisms. Importantly, the nanoparticulate systems enabled the stabilization of the pharmacologically active form of CPT, while providing protection against hydrolysis, even in physiological environments. Conclusions: In our opinion, these results underscore the promising future of biodegradable nanosystems as effective drug delivery systems (DDSs) for targeted cancer treatment, offering stability and efficacy over short, medium, and long-term applications.

In Situ Crosslinked Biodegradable Hydrogels Based on Poly(Ethylene Glycol) and Poly(ε-Lysine) for Medical Application.

Hydrogels have emerged as promising biomaterials due to their excellent performance; however, their biocompatibility, biodegradability, and absorbability still require improvement to support a broader range of medical applications. This paper presents a new biofunctionalized hydrogel based on in situ crosslinking between maleimide-terminated four-arm-poly(ethylene glycol) (4-arm-PEG-Mal) and poly(ε-lysine) (ε-PL). The PEG/ε-PL hydrogels, named LG-n, were rapidly formed via amine/maleimide reaction by mixing 4-arm-PEG-Mal and ε-PL under physiological conditions. The corresponding dry gels (DLG-n) were obtained through a freeze-drying technique. 1H NMR, FT-IR, and SEM were utilized to confirm the structures of 4-arm-PEG-Mal and LG-n (or DLG-n), and the effects of solid content on the physicochemical properties of the hydrogels were investigated. Although high solid content could increase the swelling ratio, all LG-n samples exhibited a low equilibrium swelling ratio of less than 30%. LG-7, which contained moderate solid content, exhibited optimal compression properties characterized by a compressive fracture strength of 45.2 kPa and a deformation of 69.5%. Compression cycle tests revealed that LG-n demonstrated good anti-fatigue performance. In vitro degradation studies confirmed the biodegradability of LG-n, with the degradation rate primarily governing the drug (ceftibuten) release efficiency, leading to a sustained release duration of four weeks. Cytotoxicity tests, cell survival morphology observation, live/dead assays, and hemolysis tests indicated that LG-n exhibited excellent cytocompatibility and low hemolysis rates (<5%). Furthermore, the broad-spectrum antibacterial activity of LG-n was verified by an inhibition zone method. In conclusion, the developed LG-n hydrogels hold promising applications in the medical field, particularly as drug sustained-release carriers and wound dressings.

Preparation of Glutathione-Regulated Sorafenib Targeted Nanodrug Delivery System and Its Antihepatocellular Carcinoma Activity.

To enhance the therapeutic effect of sorafenib (SOR) on liver cancer, we have developed a targeted nanodrug delivery system with glutathione (GSH) downregulation functionality. The preparation process comprises the synthesis of amino-functionalized mesoporous silica nanoparticles (MSN-NH2), surface modification with ethacrynic acid (EA), loading of SOR into the pores, and final surface coating with hyaluronic acid (HA) to obtain SOR@MSN-EA@HA (SMEH) nanoparticles. SMEH nanoparticles specifically enter tumor cells via CD44 receptor-mediated endocytosis. EA binds to GSH to consume it, while SOR is slowly released from the pores to exert antitumor effects while inhibiting GSH production. This results in sustained oxidative stress in the cells, thus enhancing the antitumor efficacy. Both in vitro and in vivo antitumor experiments as well as hemolysis tests have demonstrated that SMEH nanoparticles can accurately target liver cancer cells, effectively downregulate GSH concentration, exhibit good antitumor effects, and possess excellent safety, showing great potential in tumor treatment.

Preparation and performance study of heparinized multi‐walled carbon nanotube/cellulose acetate hemodialysis membrane

AbstractCurrently, the incidence of kidney failure is increasing worldwide. Hemodialysis is the main method for the treatment of kidney diseases, and the continuous development of new hemodialysis membranes is the key to improve the treatment effect and the quality of life of patients. In this study, heparinized multi‐walled carbon nanotube/cellulose acetate (Hep/MWCNTs@CA) membranes were prepared by non‐solvent induced phase separation (NIPS). The morphology and pore structure of Hep/MWCNTs@CA membranes were characterized by scanning electron microscopy (SEM). The elongation at break and tensile strength of the membranes were characterized by a mechanical property universal tester. The results showed that mechanical properties of 0.1 wt% MWCNTs enhanced the membrane is best. The water contact angle test confirmed that MWCNTs can improve the membrane hydrophilicity, and combined with the adsorption test results for proteins, it was found that the hydrophilicity can reduce the adsorption of proteins to the composite membrane and improve the blood compatibility of the material. The dialysis performance of urea and lysozyme was tested by a self‐made simulated hemodialysis device, and the clearance rates of urea and lysozyme were 84% and 47.2%, respectively, which showed that the interfacial gap between MWCNTs and CA matrix can make the composite membrane retain a high retention rate of macromolecular proteins (92.3%) and further improved the clearance rate of small and medium molecular toxins. In addition, the good blood compatibility and biocompatible properties of the materials were confirmed by hemolysis, recalcification and cytotoxicity tests on Hep/MWCNTs@CA membranes. In conclusion, the prepared Hep/MWCNTs@CA holds great potential for application in the field of hemodialysis.

Screening of bile salt hydrolase-producing lactic acid bacteria and evaluation of cholesterol-lowering activity in vitro

Hypercholesterolemia is a great threat to humans. Bile salt hydrolase (BSH)-producing lactic acid bacteria (LAB) may alleviate it, but current screening methods are inadequate. This study aimed to establish a more comprehensive in vitro method to screen BSH-producing LAB with greater potential for anti-hypercholesterolemia. Forty-one LAB were initially isolated from infant feces and 37 strains could produce BSH. Strains with BSH over 2 U/mg for sodium glycodeoxycholate and sodium taurodeoxycholate were used to analyse cholesterol degradation rate, hydrophobicity, self-aggregation, gastric fluid tolerance, and intestinal fluid tolerance. Based on the results of these indicators, Lactococcus lactis Y17, L. rhamnosus Q2, and L. fermentum Q11 with the top scores were considered anti-hypercholesterolemia candidates using a principal component analysis evaluation. Antioxidant and Caco-2 adhesion assays showed that these three strains exhibited excellent antioxidant ability and Caco-2 adhesion ability. Their total antioxidant capacity was above 0.99 μmol/L, while the Caco-2 adhesion rate was higher than 8.22%. Safety assessments, via antibiotic susceptibility and hemolysis tests, confirmed their safety. In the HepG2 cells assay, the total cholesterol content of the Y17, Q2, and Q11 groups was reduced by 0.525 mmol/L, 0.426 mmol/L, and 0.581 mmol/L, which verified the potential of the three LAB in anti-hypercholesterolemia. In addition, they could enhance cholesterol uptake and bile acid synthesis in HepG2 cells by upregulating the mRNA expression of bile acid synthase (CYP7A1 and CYP8B1) and cholesterol uptake receptors (NPC1L1 and LDLR). The results showed that the three LAB could be developed into anti-hypercholesterolemia foods with beneficial properties.

Durable and biocompatible low adhesion wound dressing material based on interfacial behaviors for wound management

Wound-dressing adhesion is a problem that has not been effectively addressed in the field of wound care for bleeding or burn wounds. Design of low adhesion wound dressing materials by leveraging interfacial behaviors has been an effective solution to this problem. However, previously reported superhydrophobic low adhesion materials either had durability or biocompatibility issue. To bridge this gap, this study presents a durable and biocompatible superhydrophobic low adhesion wound dressing material, which is designed on a normal gauze substrate with biocompatible components using a hybrid coating strategy. Outstanding low adhesion properties have been verified in vivo with bleeding wound or burn wound, with a peeling force that is only 0.3 %-14.5 % of the conventional non-woven gauze. Prepared low adhesion materials can robustly retain their superhydrophobicity and blood-repelling properties against harsh tests. Moreover, their biocompatibility has been confirmed through a series of tests including cell biocompatibility, hemolysis and skin irritation tests. With these demonstrated merits, the durable and biocompatible low adhesion material developed in this study will provide an effective solution to the wound adhesion problem in the practice of wound management.

Effective combinations of silver nanoparticles and antimicrobial peptides against antibiotic-resistant bacteria

BACKGROUND: The problem of constantly growing resistance of microorganisms to the antibiotics used forces scientists to constantly search for new antimicrobial agents. AIM: To study the antimicrobial activity and toxicity of silver nanoparticles and antimicrobial peptides with a β-hairpin structure, and to characterize their combined antimicrobial action. MATERIALS AND METHODS: The antimicrobial activity of silver nanoparticles and antimicrobial peptides against antibiotic-resistant bacteria was assessed by serial dilutions in a liquid nutrient medium, and the combined antimicrobial activity – by serial dilutions according to the “checkerboard” method. The toxicity of the substances to human cells was determined using a hemolytic test. RESULTS: The studied silver nanoparticles have pronounced antimicrobial activity and low toxicity to human erythrocytes. Silver nanoparticles containing acetylcysteine are more active against gram-negative bacteria than against gram-positive ones. Synergism of the antibacterial action was detected with the combined use of silver nanoparticles stabilized with sodium oleate and protegrin-1. A synergistic antimicrobial effect was also noted for combinations of silver nanoparticles containing acetylcysteine with protegrin-1, ricaecilin and shuchin-4. CONCLUSIONS: Effective combinations of silver nanoparticles and antimicrobial peptides have been identified that act synergistically against antibiotic-resistant bacterial strains, i.e. they multiply the effect of each other. These combinations can be used as prototypes for the development of antibacterial drugs.

Comparative Genomics and In Vitro Experiments Provide Insight into the Adaptation and Probiotic Properties of Shouchella clausii.

Shouchella clausii (S. clausii) has been marketed as an important commercial probiotic, displaying significant therapeutic effects on antibiotic-associated diarrhea and providing benefits to humans. This study aimed to explore the distribution, adaptation, and probiotic properties of S. clausii. Based on 16S rRNA gene analysis, 43 strains of S. clausii were isolated from 317 soil samples in China. Based on the genomic index of Average Nucleotide Identity (ANI) results, 41 strains were confirmed as S. clausii, while two strains, FJAT-45399 and FJAT-45335, were identified as potential novel species distinct from S. clausii. Combined phenotypic and genomic predictions indicated that S. clausii could survive under harsh conditions. Comparative genomics revealed that these isolates possess antibiotic resistance genes, as well as capabilities for bacteriocin and folate production, while lacking toxins and hemolytic activity. Hemolysis tests indicated that strain FJAT-41761 exhibited non-pathogenic γ-hemolytic activity, while also demonstrating resistance to multiple antibiotics, consistent with probiotic characteristics. These findings suggest that strain FJAT-41761 is safe and holds potential as a future probiotic.

Bisdemethoxycurcumin, a novel potent polyphenolic compound, effectively inhibits the formation of amyloid aggregates in ALS-associated hSOD1 mutant (L38R)

Protein misfolding is a biological process that leads to protein aggregation. Anomalous misfolding and aggregation of human superoxide dismutase (hSOD1) into amyloid aggregates is a characteristic feature of amyotrophic lateral sclerosis (ALS), a neurodegenerative illness. Thus, focusing on the L38R mutant may be a wise decision to comprehend the SOD1 disease process in ALS. We suggest that Bisdemethoxycurcumin (BDMC) may be a strong anti-amyloidogenic polyphenol against L38R mutant aggregation. Protein stability, hydrophobicity, and flexibility were altered when BDMC was bound to the L38R mutant, as shown by molecular dynamic (MD) simulations and molecular docking. FTIR data shows α-Helix dominance in BDMC-containing samples, with reduced β-sheet and disordered peaks, indicating the decrease of aggregate species. ThT aggregation kinetics curves show BDMC reduces L38R mutant aggregation dose-dependently, with higher BDMC concentrations yielding greater reductions. TEM images showed various quantities of amorphous aggregates, but notably, 60 μM BDMC markedly reduced aggregate density, underscoring BDMC's inhibitory effect. Hemolysis tests revealed aggregate species in BDMC-treated samples were less toxic than in L38R mutant samples alone at the same concentrations and exposure times. Overall, BDMC has substantial potential to develop highly effective inhibitors that mitigate the risk of fatal ALS.

Composition of Sodium Alginate Films Containing Copper Oxide Nanoparticles Synthesized Using Aqueous Extract of Turnera subulata Sm and Evaluation of Their Healing Potential In Vivo

ABSTRACTSodium alginate is used in wound care because of its hydrogel‐forming properties and ability to protect the wound. Copper nanoparticles have properties that inhibit the growth of microorganisms and mediate the production of essential biomolecules for the healing process, making them an excellent choice for constructing nanocomposites for wound treatment. This work aimed to synthesize copper nanoparticles using an aqueous extract of Turnera subulata Sm. and incorporate them into sodium alginate to obtain films with healing potential. The proposed system was characterized by ultraviolet–visible spectroscopy (UV–vis), Fourier‐transform infrared (FTIR), dynamic light scattering (DLS), atomic force microscopy (AFM), x‐ray crystallography, and biocompatibility verified by hemolysis test. The UV–vis analysis showed that CuO NPs absorb at 280 and 404 nm. The FTIR spectra revealed stretching and folding modes of the functional groups present in the aqueous extract of T. subulata responsible for the reduction/stabilization of the copper ion, as well as signals at 780 and 618 cm−1 originating from the CuO bond. Size estimation using DLS revealed 564.5 and 394.2 nm. AFM data showed that adding copper oxide nanoparticles (CuO NPs) changed alginate roughness, and surface imaging revealed a material with a uniform appearance. The hemolysis test showed hemocompatibility of CuO NPs at all tested concentrations. Histology showed that CuONP‐loaded alginate films accelerated the healing process.

By-product distribution and cytotoxicity assessment of ZnO-assisted photocatalytic degradation of reactive blue 250 dye

This research examined the effectiveness and feasibility of utilizing ultraviolet (UV) assisted photo-catalysis to treat wastewater effluents from textile production containing reactive blue 250 (RB 250) dye. Molecular oxygen and active species like O2•−, HO2•, H2O2 and •OH play crucial roles in the degradation process. Additionally, the degradation of dyes is influenced by several factors, including dye concentration, duration of UV irradiation, pH levels, concentration of H2O2, and the catalyst. The concentration of H2O2 and catalyst dose for the decolorization was studied at 0.6 mL and 0.5 g respectively. The discoloration was higher at low dye concentration, high H2O2 concentration, acidic conditions and high catalyst concentration. The maximum degradation (97 %) of RB 250 dye was obtained in the presence of zinc oxide nanoparticles within 90 min. The extent of decolorization of the dye was determined by UV–Vis spectroscopy. Fourier transform infrared spectroscopy (FTIR) was employed to analyze the changes in functionalities after degradation. The disappearance of characteristic peaks associated with specific groups within the dye molecule confirmed the extensive degradation of RB 250 dye. LCMS analysis was conducted to examine the intermediates and a mechanistic degradation pathway was subsequently proposed. The cytotoxicity of the irradiated dye samples was evaluated through a hemolytic test both pre and post-treatment. The findings suggest that the UV/H2O2/ZnO treatment represents a promising approach for effectively degrading RB 250 dye.

Identification of pathogenic bacteria from eggshell of leatherback sea turtle (Dermochelys coriacea) in Lampuuk Beach, Aceh Besar using 16S rRNA gene

Currently, the leatherback turtle population in Indonesia tends to decline. One of the factors that cause turtles' existence is the turtle eggs that fail to hatch because bacteria contaminate them, 80% of the reasons turtle eggs fail to hatch are due to infection by microorganisms found on the eggshell. Turtle eggs have a soft structure and there are pores that function for gas exchange and water absorption. Microorganisms in sand can infect turtle eggs through the pores and cause hatching failure. This study aims to isolate and identify pathogenic bacteria found in leatherback turtle eggshell (Dermochelys coriacea) from Lampuuk Beach, Aceh Besar, based on the 16S rRNA gene analysis. Eight eggshell samples from leatherback turtle eggs that failed and hatched were cultured on Nutrient Agar (NA) medium. Then, the samples were inoculated on a blood agar medium for haemolysis test. Molecular identification of the 16S rRNA gene was also carried out to determine bacterial species. A total of five bacterial colonies from leatherback turtle eggshells were successfully isolated consisting of two Gram-negative bacteria (Penyu Belimbing Aceh (PBA) = PBA-1 and PBA-2 and three Gram-positive bacteria (PBA-3, PBA-4, and PBA-5). Based on the haemolysis test, the five bacterial isolates were unable to haemolyze blood. Bacterial DNA of PBA-1 and PBA-2 were successfully isolated and amplified using polymerase chain reaction (PCR) with a DNA target of ~1500 bp. Analysis using BLASTN and phylogenetic tree construction showed that PBA-1 isolate had 98.64% similarity with Acinetobacter baumannii, while PBA-2 isolate had 97.82% similarity with Enterobacter kobei. Both bacteria are members of the Enterobacteriaceae family. It can be concluded that, there were two pathogenic bacteria can potentially be opportunistic pathogens found in leatherback turtle eggshells that failed or succeeded in hatching, namely A. baumannii and E. Kobei