Fabrication and characterization of thymol-loaded chitosan nanogels: improved antibacterial and anti-biofilm activities with negligible cytotoxicity

Antibacterial Effect of Euryale ferox Seed Shell Polyphenol Extract on Salmonella Typhimurium

This study aimed to evaluate the effects of Euryale ferox Seed Shell Polyphenol Extract (EFSSPE) on a foodborne pathogenic bacterium. EFSSPE showed antimicrobial activity toward Salmonella Typhimurium CICC 22956; the minimum inhibitory concentration of EFSSPE was 1.25 mg/mL, the inhibition curve also reflected the inhibitory effect of EFSSPE on the growth of S. Typhimurium. Detection of alkaline phosphatase outside the cell revealed that EFSSPE treatment damaged the cell wall integrity of S. Typhimurium. EFSSPE also altered the membrane integrity, thereby causing leaching of 260-nm-absorbing material (bacterial proteins and DNA). Moreover, the activities of succinate dehydrogenase and malate dehydrogenase were inhibited by EFSSPE. The hydrophobicity and clustering ability of cells were affected by EFSSPE. Scanning electron microscopy showed that EFSSPE treatment damaged the morphology of the tested bacteria. These results indicate that EFSSPE can destroy the cell wall integrity and alter the permeability of the cell membrane of S. Typhimurium.

Anti-Helicobacter pylori Effects of Thymus caramanicus Jalas Essential Oils: A New Antimicrobial Approach

Background

Helicobacter pylori are the principal causative factor in the etiological factors of chronic, active, or type B gastritis; peptic and duodenal ulcers; stomach carcinoma; and epithelial tissue lymphoid malignancies. It infects more than half of the population worldwide. To reduce H. pylori production, pharmacological therapy of H. pylori diseases typically involves using threefold treatment methods. However, as a result of such therapy, antimicrobial resistance is commonly developed. Alternative therapeutics for H. pylori diseases are thus of particular interest.

Methods

Thyme essential oils (EOs) obtained from T. caramanicus Jalas plants in Iran were tested for antibacterial activity against H. pylori obtained from 320 poultry specimens in this investigation. Antibacterial activity was measured using inhibition zones, minimum inhibitory concentrations (MICs), and minimum bactericidal concentrations (MBCs). The impact of T. caramanicus Jalas essential oils on H. pylori isolate cagA, vacA, and babA2 gene expression was evaluated using a quantitative real-time PCR method (p < 0.05).

Results

The chemical content of these EOs varied significantly according to chromatographic examination. Thymol, carvacrol, and terpinene-4-ol are the most abundant components in these EOs. H. pylori was recognized as a Helicobacter species with a 175-bp PCR product of 16S rRNA in 20/20 (100%). According to PCR results, all 20 (100%) isolates belonged to H. pylori. The EOs inhibited H. pylori in a dose-dependent manner, with T. caramanicus Jalas being the most effective, followed by pterygium EOs in decreasing order. At 8 mg/mL of T. caramanicus Jalas EOs, IZs against H. pylori were 27.4 ± 0.42 mm, and at 8 mg/mL of pterygium, IZs against H. pylori were 1 ± 0.02. T. caramanicus Jalas essential oils were used to treat all bacteria, and the findings showed that T. caramanicus Jalas had a substantial inhibitory impact on the expression of cagA, vacA, and babA2 virulence-related genes (p < 0.05).

Conclusions

In a dose-dependent manner, the EOs of T. caramanicus Jalas EO demonstrated a high degree of antimicrobial property against H. pylori bacteria. The most efficient EOs were those from T. caramanicus Jalas with relative concentrations of thymol and carvacrol, followed by the coumarin-dominated pterygium EO with reduced antibacterial activity.

Novel Niosome-Encapsulated 2,5-Diketopiperazine (BHPPD): Synthesis, Formulation, and Anti-breast Cancer Activity

In the course of this investigation, a brand-new noisome-encapsulated 2,5-diketopiperazine (BHPPD) was developed, synthesized, and assessed. Utilizing CCK-8, invasion screens, MTT test, flow cytometry, and cell cycle analysis, we evaluated the anti-breast cancer properties of niosome-encapsulated BHPPD. Apoptosis-related gene expression and cytotoxicity was measured using quantitative real-time PCR and MTT assays. This meta-analysis showed a significant drug-binding affinity for intestinal protease. The spherical mean diameters of the free BHPPD, the F1 niosomal-BHPPD, and the F2 niosomal-BHPPD were all determined to be108.91 ± 4.2, 129.13 ± 7.2 nm, and 149.43 ± 3.2 nm, respectively. Also, it was found that the entrapment efficiency (EE%) of the F1 formulations of BHPPD that was niosome-encapsulated was 81.01 0.09% and that it was 70.22 0.13%, respectively. Early, late, necrotic, and viable MCF-7 cells were present in the cells with F1 formulation in proportions of 38.24%, 34.34%, 4.02%, and 23.40%, respectively. Compared to the control group, the treatment group's expression of the genes P57, Prkca, MDM4, Map2k6, and FADD was considerably greater (P < 0.001). Furthermore, compared to control cells, cells in the treatment group expressed less BCL2 and survival genes (P < 0.001). Moreover, formulations of BHPPD encapsulated in niosomes showed a biocompatible nanoscale delivery method and exhibited little cytotoxicity against the HEK-293 standard cell line. According to the findings, formulations of BHPPD with niosome-encapsulation might be viable for boosting anticancer activity.

Fabrication and antimicrobial properties of novel meropenem-honey encapsulated chitosan nanoparticles against multiresistant and biofilm-forming Staphylococcus aureus as a new antimicrobial agent

BACKGROUND

Honey exhibits a broad spectrum of antibacterial activity against Gram-positive and Gram-negative bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) ones. Chitosan (Cs) is a mucoadhesive polymer that also has antibacterial properties. Special attention has been paid to the design of polymeric nanoparticles (NPs) as new nano drug delivery systems to overcome bacterial resistance and its problems.

OBJECTIVES

The aim of the present study is to synthesize Cs-meropenem NPs with/without honey as an antibiofilm and antibacterial agent to inhibit Staphylococcus aureus.

METHODS

This study synthesized meropenem and honey-loaded Cs nanogels and subsequently characterized them by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), and DLS-zeta potential. Using the broth microdilution and crystal violet assays, the antibacterial and antibiofilm activity of meropenem and honey-loaded Cs nanogel, free meropenem, free honey, and free Cs NPs were investigated in vitro against MRSA strains. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) was also used to test the cytotoxicity of several Cs-NPs compound against the HEK-293 regular cell line.

RESULTS

The average size of meropenem and honey-Cs-NPs was reported to be 119.885 nm, and encapsulation efficiency was 88.33 ± 0.97 with stability up to 60 days at 4°C. The NPs showed enhanced antibiofilm efficacy against S. aureus at sub-minimum inhibitory concentrations. Additionally, the cytotoxicity of meropenem and honey-encapsulated Cs against the HEK-293 normal cell line was insignificant.

CONCLUSIONS

Our findings suggested that meropenem and honey-Cs-NPs might be potential antibacterial and antibiofilm materials.

Development and characterization of a topical gel, containing lavender (Lavandula angustifolia) oil loaded solid lipid nanoparticles

Gels loaded with nanocarriers offer interesting ways to create novel therapeutic approaches by fusing the benefits of gel and nanotechnology. Clinical studies indicate that lavender oil (Lav-O) has a positive impact on accelerating wound healing properly based on its antimicrobial and anti-inflammatory effects. Initially Lav-O loaded Solid Lipid Nanoparticles (Lav-SLN) were prepared incorporating cholesterol and lecithin natural lipids and prepared SLNs were characterized. Next, a 3% SLN containing topical gel (Lav-SLN-G) was formulated using Carbopol 940. Both Lav-SLN and Lav-SLN-G were assessed in terms antibacterial effects against S. aureus. Lav-SLNs revealed a particle size of 19.24 nm, zeta potential of -21.6 mv and EE% of 75.46%. Formulated topical gel presented an acceptable pH and texture properties. Minimum Inhibitory/Bactericidal Concentration (MIC/MBC) against S. aureus for LAv-O, Lav-SLN and Lav-SLN-G were 0.12 and 0.24 mgml- 1, 0.05 and 0.19 mgml- 1 and 0.045, 0.09 mgml- 1, respectively. Therefore, SLN can be considered as an antimicrobial potentiating nano-carrier for delivery of Lav-O as an antimicrobial and anti-inflammatory agent in topical gel.

Inhibitory effect of natural compounds on quorum sensing system in Pseudomonas aeruginosa: a helpful promise for managing biofilm community

Pseudomonas aeruginosa biofilm is a community of bacteria that adhere to live or non-living surfaces and are encapsulated by an extracellular polymeric substance. Unlike individual planktonic cells, biofilms possess a notable inherent resistance to sanitizers and antibiotics. Overcoming this resistance is a substantial barrier in the medical and food industries. Hence, while antibiotics are ineffective in eradicating P. aeruginosa biofilm, scientists have explored alternate strategies, including the utilization of natural compounds as a novel treatment option. To this end, curcumin, carvacrol, thymol, eugenol, cinnamaldehyde, coumarin, catechin, terpinene-4-ol, linalool, pinene, linoleic acid, saponin, and geraniol are the major natural compounds extensively utilized for the management of the P. aeruginosa biofilm community. Noteworthy, the exact interaction of natural compounds and the biofilm of this bacterium is not elucidated yet; however, the interference with the quorum sensing system and the inhibition of autoinducer production in P. aeruginosa are the main possible mechanisms. Noteworthy, the use of different drug platforms can overcome some drawbacks of natural compounds, such as insolubility in water, limited oral bioavailability, fast metabolism, and degradation. Additionally, drug platforms can deliver different antibiofilm agents simultaneously, which enhances the antibiofilm potential of natural compounds. This article explores many facets of utilizing natural compounds to inhibit and eradicate P. aeruginosa biofilms. It also examines the techniques and protocols employed to enhance the effectiveness of these compounds.

Chitosan-LeoA-DNA Nanoparticles Promoted the Efficacy of Novel LeoA-DNA Vaccination on Mice Against Helicobacter pylori

More than half of the world's population is infected with Helicobacter pylori (H. pylori), which may lead to chronic gastritis, peptic ulcers, and stomach cancer. LeoA, a conserved antigen of H. pylori, aids in preventing this infection by triggering specific CD3+ T-cell responses. In this study, recombinant plasmids containing the LeoA gene of H. pylori are created and conjugated with chitosan nanoparticle (CSNP) to immunize BALB/c mice against the H. pylori infection. We used the online Vaxign tool to analyze the genomes of five distinct strains of H. pylori, and we chose the outer membrane as a prospective vaccine candidate. Afterward, the proteins' immunogenicity was evaluated. The DNA vaccine was constructed and then encapsulated in CSNPs. The effectiveness of the vaccine's immunoprotective effects was evaluated in BALB/c mice. Purified activated splenic CD3+ T cells are used to test the anticancer effects in vitro. Nanovaccines had apparent spherical forms, were small (mean size, 150-250 nm), and positively charged (41.3 ± 3.11 mV). A consistently delayed release pattern and an entrapment efficiency (73.35 ± 3.48%) could be established. Compared to the non-encapsulated DNA vaccine, vaccinated BALB/c mice produced higher amounts of LeoA-specific IgG in plasma and TNF-α in splenocyte lysate. Moreover, BALB/c mice inoculated with nanovaccine demonstrated considerable immunity (87.5%) against the H. pylori challenge and reduced stomach injury and bacterial burdens in the stomach. The immunological state in individuals with GC with chronic infection with H. pylori is mimicked by the H. pylori DNA nanovaccines by inducing a shift from Th1 to Th2 in the response. In vitro human GC cell development is inhibited by activated CD3+ T lymphocytes. According to our findings, the H. pylori vaccine-activated CD3+ has potential immunotherapeutic benefits.

Antimicrobial and antibiofilm activity of highly soluble polypyrrole against methicillin-resistant Staphylococcus aureus

AIMS

The purpose was to evaluate the antimicrobial activity of highly soluble polypyrrole (Hs-PPy), alone or combined with oxacillin, as well as its antibiofilm potential against methicillin-resistant Staphylococcus aureus strains. Furthermore, the in silico inhibitory mechanism in efflux pumps was also investigated.

METHODS AND RESULTS

Ten clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and two reference strains were used. Antimicrobial activity was determined by broth microdilution, and the combination effect with oxacillin was evaluated by the checkerboard assay. The biofilm formation capacity of MRSA and the interference of Hs-PPy were evaluated. The inhibitory action of Hs-PPy on the efflux pump was evaluated in silico through molecular docking. Hs-PPy showed activity against the isolates, with inhibitory action between 62.5 and 125 µg ml-1 and bactericidal action at 62.5 µg ml-1, as well as synergism in association with oxacillin. The isolates ranged from moderate to strong biofilm producers, and Hs-PPy interfered with the formation of this structure, but not with mature biofilm. There was no in silico interaction with the efflux protein EmrD, the closest homolog to NorA.

CONCLUSIONS

Hs-PPy interferes with biofilm formation by MRSA, has synergistic potential, and is an efflux pump inhibitor.

Preparation of the Myricetin-Loaded PEGylated Niosomes and Evaluation of their in vitro Anti-Cancer Potentials

Several edible plants contain flavonoids, including myricetin (Myr), which perform a wide range of biological activities. Myr has antitumor properties against various tumor cells. In this study Myr-loaded PEGylated niosomes (Myr-PN) were prepared and their anti-cancer activities were evaluated in vitro. Myr-PNs were prepared as a tool for drug delivery to the tumor site. Myr-PN was characterized in terms of size, zeta potential, and functional groups using dynamic light scattering (DLS), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (SEM). The Myr-PN size was 241 nm with a polydispersity index (PDI) of 0.20, and zeta potential -32.7±6.6 mV. Apoptotic properties of Myr-PN against normal and cancer cell lines were determined by flow cytometry and real-time quantitative PCR. Cancer cells showed higher cytotoxicity when treated with Myr-PN compared with normal cells, indicating that the synthesized nanoparticles pose no adverse effects. Apoptosis was induced in cells treated with 250 μg/mL of Myr-PN, in which 45.2 % of cells were arrested in subG1, suggesting that Myr-PN can induce apoptosis. In vitro, the synthesized Myr-PN demonstrated potent anticancer properties. Furthermore, more research should be conducted in vitro and in vivo to study the more details of Myr-PN anti-cancer effects.

Regulation and mechanism of organic selenium on quorum sensing, biofilm, and antioxidant effects of Lactobacillus paracasei

Different organic compounds can have varying degrees of impact on the activity of Lactobacillus paracasei. The study focused on the impact and action mechanism of different organic selenium products on the bioactivity of two strains of L. paracasei. The growth, antioxidant activity, extracellular polysaccharide secretion, quorum sensing (QS), and biofilm formation of the strains before and after the addition of organic selenium crude products and three organic selenium standard were evaluated. The results showed that the addition of crude organic selenium promoted the various activities of the strain. l-selenocysteine had the strongest regulatory effect, with maximum GIM1.80 biofilm formation when it reached a critical concentration of 0.4 μg/mL; l-selenomethionine resulted in the highest activity of the signal molecule Auto inducer-2 of GDMCC1.155, when it reached a critical concentration of 0.4 μg/mL. The results of scanning electron microscopy demonstrated that the addition of organic selenium effectively improved the morphological structure of the two bacterial cells. Molecular docking revealed that the mechanism by which organic selenium regulates QS in Lactobacillus was achieved by binding two crucial receptor proteins (histidine protein kinase HKP and periplasmic binding protein LuxP) from specific sites. Furthermore, organic selenium products have a beneficial regulatory effect on the biological activity of L. paracasei. Overall, these findings provide a new alternative (organic selenium) for regulating the viability and beneficial activity of L. paracasei.

A comprehensive investigation of the medicinal efficacy of antimicrobial fusion peptides expressed in probiotic bacteria for the treatment of pan drug-resistant (PDR) infections

The present work aimed to examine the intracellular antibacterial efficacy of Recombinant Lactobacillus acidophilus/antimicrobial peptides (AMPs) Melittin and Alyteserin-1a, specifically targeting Gram-negative bacteria. The first assessment was to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Recombinant L. acidophilus/AMPs versus Gram-negative and Gram-positive bacteria. In addition, the researchers examined the in vitro viability and safety of AMPs generated by L. acidophilus. The experiments included exposing the AMPs to elevated temperatures, proteases, cationic salts at physiological levels, and specific pH settings. The safety aspect was evaluated using hemolytic analysis utilizing sheep erythrocytes; cytotoxicity assays employing cell lines, and experiments on beneficial gut lactobacilli. An experiment was done using a time-kill method to assess the intracellular antibacterial efficacy of Recombinant L. acidophilus/AMPs compared to pathogenic varieties in HEp-2 cells. Previous investigations have shown that the MBC levels of recombinant L. acidophilus/AMPs were consistently two to four times higher than the equivalent MIC values when evaluated versus Gram-negative bacteria. Furthermore, the stability of the Recombinant L. acidophilus/AMPs showed variability when exposed to elevated temperatures (70 and 90 ℃), treated with protease enzymes (proteinase K, lysozyme), exposed to higher concentrations of physiological salts (150 mM NaCl and 2 mM MgCl2), and varying pH levels (ranging from 4.0 to 9.0). The recombinant L. acidophilus/AMPs are non-hemolytic towards sheep erythrocytes, exhibit little cytotoxicity in RAW 264.7 and HEp-2 cells, and are considered safe when compared to beneficial gut lactobacilli. The research examined the intracellular bacteriostatic effects of recombinant L. acidophilus/AMPs on Gram-negative bacteria inside HEp-2 cells. Nevertheless, no notable bactericidal impact was seen on Gram-positive bacteria (P > 0.05). The research shows that recombinant L. acidophilus/AMPs, namely (L. acidophilus/melittin/Alyteserin-1a) as the focus of the investigation, effectively eliminate Gram-negative bacteria. Therefore, more investigation is necessary to elaborate on these discoveries.

Thymol as a Component of Chitosan Systems-Several New Applications in Medicine: A Comprehensive Review

Thymol, a plant-derived monoterpene phenol known for its broad biological activity, has often been incorporated into chitosan-based biomaterials to enhance therapeutic efficacy. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, we conducted a systematic literature review from 2018 to 2023, focusing on the biomedical implications of thymol-loaded chitosan systems. A review of databases, including PubMed, Scopus, and Web of Science was conducted using specific keywords and search criteria. Of the 90 articles, 12 were selected for the review. Thymol-loaded chitosan-based nanogels (TLCBS) showed improved antimicrobial properties, especially against multidrug-resistant bacterial antagonists. Innovations such as bipolymer nanocarriers and thymol impregnated with photosensitive chitosan micelles offer advanced bactericidal strategies and show potential for bone tissue regeneration and wound healing. The incorporation of thymol also improved drug delivery efficiency and biomechanical strength, especially when combined with poly(dimethylsiloxane) in chitosan-gelatin films. Thymol-chitosan combinations have also shown promising applications in oral delivery and periodontal treatment. This review highlights the synergy between thymol and chitosan in these products, which greatly enhances their therapeutic efficacy and highlights the novel use of essential oil components. It also highlights the novelty of the studies conducted, as well as their limitations and possible directions for the development of integrated substances of plant and animal origin in modern and advanced medical applications.

pH-sensitive niosomes for ATRA delivery: A promising approach to inhibit Pin1 in high-grade serous ovarian cancer

The peptidyl-prolyl cis/trans isomerase Pin1 positively regulates numerous cancer-driving pathways, and it is overexpressed in several malignancies, including high-grade serous ovarian cancer (HGSOC). The findings that all-trans retinoic acid (ATRA) induces Pin1 degradation strongly support that ATRA treatment might be a promising approach for HGSOC targeted therapy. Nevertheless, repurposing ATRA into the clinics for the treatment of solid tumors remains an unmet need mainly due to the insurgence of resistance and its ineffective delivery. In the present study, niosomes have been employed for improving ATRA delivery in HGSOC cell lines. Characterization of niosomes including hydrodynamic diameter, ζ-potential, morphology, entrapment efficiency and stability over time and in culture media was performed. Furthermore, pH-sensitiveness and ATRA release profile were investigated to demonstrate the capability of these vesicles to release ATRA in a stimuli-responsive manner. Obtained results documented a nanometric and monodispersed samples with negative ζ-potential. ATRA was efficiently entrapped, and a substantial release was observed in the presence of acidic pH (pH 5.5). Finally, unloaded niosomes showed good biocompatibility while ATRA-loaded niosomes significantly increased ATRA Pin1 inhibitory activity, which was consistent with cell growth inhibition. Taken together, ATRA-loaded niosomes might represent an appealing therapeutic strategy for HGSOC therapy.

Antibacterial and antibiofilm effects of green synthesized selenium nanoparticles on clinical Klebsiella pneumoniae isolates

Nanotechnology covers many disciplines, including the biological sciences. In this study, selenium nanoparticles (Se-NPs) were synthesized using Artemisia annua extract and investigated against clinical strains of klebsiella pneumoniae (K. pneumoniae) for their anti-biofilm effects. In this experimental study, from May 1998 to September 1998, 50 clinical samples of blood, urine, and sputum were collected, and K. pneumoniae strains were isolated using microbiological methods. Subsequently, the antibacterial effects of Se-NPs at concentrations of 12-25-50-100/5-6/3-25/125 μg/mL were studied. Finally, biofilm-producing strains were isolated, and the expression of mrkA biofilm gene was studied in real-time strains treated with Se-NPs using real-time polymerase chain reaction (PCR). Out of 50 clinical samples, 20 strains of K. pneumoniae were isolated. Minimum inhibitory concentration (MIC) results of Se-NPs showed that Se-NPs were capable of significant cell killing. Real-time PCR results also showed that mrkA gene expression was significantly reduced in strains treated with Se-NPs. According to this study, Se-NPs could reduce bacterial growth and biofilm formation, therefore, could be considered a candidate drug in the medical application for infections caused by K. pneumoniae.

Putative novel outer membrane antigens multi-epitope DNA vaccine candidates identified by Immunoinformatic approaches to control Acinetobacter baumannii

Multi-epitope polypeptide vaccines, a fusion protein, often have a string-of-beads system composed of various specific peptide epitopes, potential adjuvants, and linkers. When choosing the sequence of various segments and linkers, many alternatives are available. These variables can influence the vaccine's effectiveness through their effects on physicochemical properties and polypeptide tertiary structure.The most conserved antigens were discovered using BLASTn. To forecast the proteins' subcellular distribution, PSORTb 3.0.2 was used. Vaxign was used for the preliminary screening and antigenicity assessment. Protein solubility was also predicted using the ccSOL omics. Using PRED-TMBB, it was anticipated that the protein would localize across membranes. The IEDB and BepiPred-2.0 databases were used to predict the immunogenicity of B cell epitopes. A multi-epitope construct was developed and analyzed to evaluate. Twenty epitopes from A. baumannii's outer membrane protein (omp) were included in the vaccination. TLR4 agonist explosibility was investigated. The physicochemical characteristics, secondary and tertiary structures, and B-cell epitopes of vaccine constructs were assessed. Additionally, docking and MD experiments were used to examine the relationship between TLR4 and its agonist.Thirteen antigens were discovered, and eight of the 13 chosen proteins were predicted to be surface proteins. The 34 kDa outer membrane protein, Omp38, Omp W, CarO, putative porin, OmpA, were chosen as having the right antigenicity (≥0.5). FhuE and CdiA were eliminated from further study because of their low antigenicity. The vaccine design was developed by combining the most effective 10 B-cell and 10 MHC-I/MHCII combined coverage epitopes. The molecular formula of the vaccine was determined to be C1718H2615N507O630S17. The vaccine form has a molecular weight of 40,996.70 Da and 47 negatively charged residues (Asp + Glu), whereas 28 positively charged residues (Arg + Lys). The estimated half-life was 7.2 hours (mammalian reticulocytes, in vitro), > 20 hours (yeast, in vivo) and > 10 hours (Escherichia coli, in vivo) for the vaccine. The multi-epitope vaccine insertion is carried via the expression vector pcDNA3.1 (+).The multi-epitope vaccine may stimulate humoral and cellular immune responses, according to our findings, and it may be a candidate for an A. baumannii vaccine.

Thymol-Functionalized Hyaluronic Acid as Promising Preservative Biomaterial for the Inhibition of Candida albicans Biofilm Formation

Hyaluronic acid (HA) is a naturally occurring biopolymer that has been employed for a plethora of medicinal applications. Nevertheless, as HA is a natural polysaccharide, it can be a substrate able to promote microbial growth and proliferation. Biopolymer-drug conjugates have gained attention over the years to overcome drawbacks of each single component. Within this context, thymol (Thy), a phenolic compound occurring in essential oils (EOs) extracted from Thymus and Origanum, has been largely studied for its antimycotic applications. However, it is characterized by a low water solubility and moderate cytotoxicity. Herein, we report an innovative HA-thymol conjugate (HA-Thy) biomaterial to circumvent the drawbacks of free thymol use by providing the polymer conjugate with the beneficial properties of both components. Preliminary biological tests evidenced the decrease of thymol cytotoxicity for the HA-Thy conjugate, paired with a promising antibiofilm formation activity against Candida albicans, similar to pure thymol, highlighting its potential application as a preservative biomaterial in formulations.

Recent Advances in Chitosan-Based Applications-A Review

Chitosan derived from chitin gas gathered much interest as a biopolymer due to its known and possible broad applications. Chitin is a nitrogen-enriched polymer abundantly present in the exoskeletons of arthropods, cell walls of fungi, green algae, and microorganisms, radulae and beaks of molluscs and cephalopods, etc. Chitosan is a promising candidate for a wide variety of applications due to its macromolecular structure and its unique biological and physiological properties, including solubility, biocompatibility, biodegradability, and reactivity. Chitosan and its derivatives have been known to be applicable in medicine, pharmaceuticals, food, cosmetics, agriculture, the textile and paper industries, the energy industry, and industrial sustainability. More specifically, their use in drug delivery, dentistry, ophthalmology, wound dressing, cell encapsulation, bioimaging, tissue engineering, food packaging, gelling and coating, food additives and preservatives, active biopolymeric nanofilms, nutraceuticals, skin and hair care, preventing abiotic stress in flora, increasing water availability in plants, controlled release fertilizers, dye-sensitised solar cells, wastewater and sludge treatment, and metal extraction. The merits and demerits associated with the use of chitosan derivatives in the above applications are elucidated, and finally, the key challenges and future perspectives are discussed in detail.

Targeted pH-responsive chitosan nanogels with Tanshinone IIA for enhancing the antibacterial/anti-biofilm efficacy

Persistent bacterial infection caused by biofilms is one of the most serious problems that threatened human health. The development of antibacterial agents remains a challenge to penetrate biofilm and effectively treat the underlying bacterial infection. In the current study, chitosan-based nanogels were developed for encapsulating the Tanshinone IIA (TA) to enhance the antibacterial and anti-biofilm efficacy against Streptococcus mutans (S. mutans). The as-prepared nanogels (TA@CS) displayed excellent encapsulation efficiency (91.41 ± 0.11 %), uniform particle sizes (393.97 ± 13.92 nm), and enhanced positive potential (42.27 ± 1.25 mV). After being coated with CS, the stability of TA under light and other harsh environments was greatly improved. In addition, TA@CS displayed pH responsiveness, allowing it to selectively release more TA in acidic conditions. Furthermore, the positively charged TA@CS were equipped to target negatively charged biofilm surfaces and efficiently penetrate through biofilm barriers, making it promising for remarkable anti-biofilm activity. More importantly, when TA was encapsulated into CS nanogels, the antibacterial activity of TA was enhanced at least 4-fold. Meanwhile, TA@CS inhibited 72 % of biofilm formation at 500 μg/mL. The results demonstrated that the nanogels constituted CS and TA had antibacterial/anti-biofilm properties with synergistic enhanced effects, which will benefit pharmaceutical, food, and other fields.

Distribution of Virulence Genes in Campylobacter spp. Isolated from Agaricus Mushrooms in Iran

The white button mushroom (Agaricus) is a significant nutritional and therapeutic species utilized in the human diet and could transmit various bacterial infections. Campylobacter species are the most common cause of foodborne illness across the world. The present study has been planned to determine the frequency of virulence genes and antibiotic susceptibility test in Campylobacter spp. recovered from Agaricus mushroom. In this study, 740 Agaricus mushroom samples were gathered randomly from various markets from June 2020 to December 2020. Confirmation of Campylobacter spp. using biochemical analyses and 23S rRNA-based PCR was performed. The agar dilution technique was used to determine resistance to antibiotics using gentamicin (GM10μg), ciprofloxacin (CIP5μg), nalidixic acid (NA30μg), tetracycline (TE30μg), ampicillin (AM10μg), amoxicillin+ clavulanic acid (AMC30μg), erythromycine (E15μg), azithromycin (AZM15μg), clindamycin (CC2μg), and chloramphenicol (C30μg). Multiplex PCR was utilized to determine the prevalence of the recR, dnaJ, wlaN, virBll, cdtC, cdtB, cdtA, flaA, cadF, pidA, ciaB, ceuE, and cgtB genes. Campylobacter spp. were detected in 74 out of 740 Agaricus mushroom samples (10%). According to the data, Agaricus mushroom samples included 32 (4.32%) C. jejuni, 11 (1.48%) C. coli, and 31 (4.18%) other Campylobacter spp. Antimicrobial resistance was most common in C. jejuni isolates. C. jejuni isolates also had the lowest resistance rate to gentamycin, ciprofloxacin, and nalidixic acid. C. coli isolates were reported to have the highest antimicrobial resistance to ciprofloxacin, ampicillin, and erythromycine. Resistance to gentamycin and amoxicillin+ clavulanic acid was likewise lowest among C. coli strains. The flaA and ciaB genes were found in 100% of B-lactams-susceptible C. jejuni and C. coli strains. When examining the relationship between antibiotic resistance and the existence of virulence genes, it was observed that there is a statistically significant relationship (p < 0.001) between bacterial resistance and virulence genes. Our findings indicated that changes in resistance patterns in Campylobacter strains have emerged from multiple treatment approaches in Agaricus mushrooms.

Evaluation of Apoptosis, Cell Proliferation and Cell Cycle Progression by Inactivation of the NEAT1 Long Noncoding RNA in a Renal Carcinoma Cell Line Using CRISPR/Cas9

Background

Long noncoding RNAs (lncRNAs) play an important role in cellular mechanisms including transcription, translation, and apoptosis. NEAT1 is one of the essential types of lncRNAs in humans that can bind to active genes and modify their transcription. NEAT1 upregulation in various forms of cancer such as kidney cancer has been reported. Kidney cancer accounts for approximately 3% of all cancers worldwide and occurs almost twice as often in men as in women.

Objectives

This study has been performed to knockout the NEAT1 gene using the CRISPR/Cas9 technique in the Renal Cell Carcinoma ACHN cell line and to evaluate its effects on cancer progression and apoptosis.

Material and Methods

Two specific (single guide RNA (sgRNA) sequences for the NEAT1 gene were designed by CHOPCHOP software. These sequences were then cloned into plasmid pSpcas9, and recombinant vectors PX459-sgRNA1 and PX459-sgRNA2 were generated. ACHN cells were transfected using recombinant vectors carrying sgRNA1 and sgRNA2. The expression level of apoptosis-related genes was assessed by real-time PCR. Annexin, MTT and cell scratch tests were performed to evaluate the survival, proliferation, and migration of the knocked out cells, respectively.

Results

The results have shown successful knockout of the NEAT1 gene in the cells of the treatment group. Expressions of P53, BAK, BAX and FAS genes in the cells of the treatment group (NEAT1 knockout) showed significant increases in expression compared to the cells of the control group (P <0.01). Additionally, decreased expression of BCL2 and survivin genes was observed in knockout cells compared to the control group (p <0.05). In addition, in the cells of the treatment group compared to control cells, a significant decrease in cell viability, ability to migrate and cell growth and proliferation was observed.

Conclusion

Inactivation of the NEAT1 gene in ACHN cell line using CRISPR/Cas9 technology elevated apoptosis and reduced cell survival and proliferation which makes it a novel target for kidney cancer therapeutics.

Niosomes-loaded selenium nanoparticles as a new approach for enhanced antibacterial, anti-biofilm, and anticancer activities

Targeted drug delivery and increasing the biological activity of drugs is one of the recent challenges of pharmaceutical researchers. Niosomes are one of the new targeted drug delivery systems that enhances the biological properties of drugs. In this study, for the first time, the green synthesis of selenium nanoparticles (SeNPs), and its loading into niosome was carried out to increase the anti-bacterial and anti-cancer activity of SeNPs. Different formulations of noisome-loaded SeNPs were prepared, and the physical and chemical characteristics of the prepared niosomes were investigated. The antibacterial and anti-biofilm effects of synthesized niosomes loaded SeNPs and free SeNPs against standard pathogenic bacterial strains were studied, and also its anticancer activity was investigated against breast cancer cell lines. The expression level of apoptotic genes in breast cancer cell lines treated with niosome-loaded SeNPs and free SeNPs was measured. Also, to evaluate the biocompatibility of the synthesized niosomes, their cytotoxicity effects against the human foreskin fibroblasts normal cell line (HFF) were studied using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. The results illustrated that the optimal formulation had an average size of 177.9 nm, a spherical shape, and an encapsulation efficiency of 37.58%. Also, the results revealed that the release rate of SeNPs from niosome-loaded SeNPs and free SeNPs was 61.26% and 100%, respectively, in 72 h. Also, our findings demonstrated that the niosome-loaded SeNPs have significant antibacterial, anti-biofilm, and anticancer effects compared to the free SeNPs. In addition, niosome-loaded SeNPs can upregulate the expression level of Bax, cas3, and cas9 apoptosis genes while the expression of the Bcl2 gene is down-regulated in all studied cell lines, significantly. Also, the results of the MTT test indicated that the free niosome has no significant cytotoxic effects against the HFF cell line which represents the biocompatibility of the synthesized niosomes. In general, based on the results of this study, it can be concluded that niosomes-loaded SeNPs have significant anti-microbial, anti-biofilm, and anti-cancer effects, which can be used as a suitable drug delivery system.

Targeting the MALAT1 gene with the CRISPR/Cas9 technique in prostate cancer

Background

The MALAT1 lncRNA acts as an oncogene in Prostate cancer (PC); thus, it can be severe as a cancer biomarker.

Methods

Using bioinformatics datasets including (HTSeq-Counts, GDC, and TCGA) 5501 gene expression profiling specimens were gathered. Then, expression profiles and sample survival of lncRNA were investigated using COX regression analyses, ROC curve analysis. The Database for Annotation, Visualization, and Integrated Discovery was used to conduct GO and KEGG studies on the lncRNA-related PCGs. After MALAT1 Knockout via CRISPR/Cas9 technique, the MALAT1 expression was assessed in DU-145 cells. The deletion of the target fragment was examined by polymerase chain reaction (PCR). Also, the expression of apoptosis genes was investigated by qRT-PCR. The viability and cell proliferation were measured using the MTT assay. Cell migration capability was determined using the cell scratch assay. The results of qRT-PCR were assessed by the ΔΔCt method, and finally, statistical analysis was performed in SPSS software.

Results

A maximum of 451 lncRNAs were discovered to reflect different expressions between PC and non-carcinoma tissue samples, with 307 being upregulated and 144 being down-regulated. Thirty-six lncRNAs related to OS were carefully selected, which were then subjected to stepwise multivariate Cox regression analysis, with 2 lncRNAs (MALAT1, HOXB-AS3). MALAT1 is highly expressed in PC cells. MALAT1 Knockout in DU-145 cells increases apoptosis and prevents proliferation and migration, and DU-145 transfected cells were unable to migrate based on the scratch recovery test. Overall, data suggest that MALAT1 overexpression in PC helps metastasis and tumorigenesis. Also, MALAT1 knockout can be considered a therapeutic and diagnostic target in PC.

Conclusion

Targeting MALAT1 by CRISPR/Cas9 technique inhibit the cell proliferation and migration, and in addition induce apoptosis. Thus, MALAT1 can act as a tumor biomarker and therapeutic target.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41021-022-00252-3.

CRISPR/Cas9-mediated LINC00511 knockout strategies, increased apoptosis of breast cancer cells via suppressing antiapoptotic genes

Background

The growing detection of long noncoding RNAs (lncRNAs) required the application of functional approaches in order to provide absolutely precise, conducive, and reliable processed information along with effective consequences. We utilized genetic knockout (KO) techniques to ablate the Long Intergenic Noncoding RNA 00,511 gene in several humans who suffered from breast cancer cells and at the end we analyzed and examined the results.

Results

The predictive relevance of LINC00511 expression pattern was measured by using a pooled hazard ratio (HR) with a 95% confidence interval (CI). The link among LINC00511 expression profiles and cancer metastasis was measured by using a pooled odds ratio (OR) with a 95% confidence interval. This meta- analysis was composed of fifteen studies which contained a total of 1040 tumor patients. We used three distinct CRISPR/Cas9-mediated knockdown techniques to prevent the LINC00511 lncRNA from being transcribed. RT-PCR was used to measure lncRNA and RNA expression. We used CCK-8, colony formation tests, and the invasion transwell test to measure cell proliferation and invasion. The stemness was measured by using a sphere-formation test. To validate molecular attachment, luciferase reporter assays were performed. The functional impacts of LINC00511 gene deletion in knockdown breast cancer cell lines were confirmed by using RT-qPCR, MTT, and a colony formation test. This meta-analysis was composed of 15 trials which contained a total of 1040 malignant tumors. Greater LINC00511 expression was ascribed to a lower overall survival (HR = 1.93, 95% CI 1.49–2.49, < P 0.001) and to an increased proportion of lymph node metastasis (OR = 3.07, 95% CI 2.23–4.23, P < 0.001) in the meta‐analysis. It was found that the role of LINC00511 was overexpressed in breast cancer samples, and this overexpression was ascribed to a poor prognosis. The gain and loss-of-function tests demonstrated findings such as LINC00511 increased breast cancer cell proliferation, sphere-forming ability, and tumor growth. Additionally, the transcription factor E2F1 binds to the Nanog gene's promoter site to induce transcription. P57, P21, Prkca, MDM4, Map2k6, and FADD gene expression in the treatment group (LINC00511 deletion) was significantly higher than in the control group (P < 0.01). In addition, knockout cells had lower expression of BCL2 and surviving genes than control cells P < 0.001). In each of the two target alleles, the du-HITI approach introduced a reporter and a transcription termination signal. This strategy's donor vector preparation was significantly easier than "CRISPR HDR," and cell selection was likewise much easier than "CRISPR excision." Furthermore, when this approach was used in the initial transfection attempt, single-cell knockouts for both alleles were generated.

Conclusions

The methods employed and described in this work could be extended to the production of LINC00511 knockout cell lines and, in theory, to the deletion of other lncRNAs to study their function.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12575-022-00171-1.

Identification of Antigenic Properties of Acinetobacter baumannii Proteins as Novel Putative Vaccine Candidates Using Reverse Vaccinology Approach

Multidrug-resistant Acinetobacter baumannii (A. baumannii) infections are becoming more prevalent all over the world. As a cost-effective and preventative method, vaccination seems to be required against this bacterium. In the present study, subtractive proteomics along with reverse vaccinology approaches was used to predict suitable therapeutics against A. baumannii. Using the Vaxign online tool, we studied over 35 genomes of A. baumannii strains and chose outer membrane and secreted proteins of A. baumannii 1656-2 as possible vaccine candidates. Then, investigations were performed on the immunogenicity, antigenic characteristics, physicochemical properties, B-cell and MHC class I, and MHC class II molecules epitope densities of proteins. After optimizing the codon of the proteins, the pcDNA3.1( +) expression construct was designed and the immunogenicity, allergenicity, and physicochemical properties of the vaccine construct were predicted. Hcp and OmpC proteins were predicted as extracellular and outer membrane proteins, respectively. These proteins interact with 10 other proteins to form a network of protein interactions with virulence properties. Immunoassays of Hcp and OmpC proteins showed antigenicity of 0.88 and 0.79, respectively. These proteins have 5 structural cell epitope points and 5 linear B epitope points. They are also able to bind to different HLA alleles of MCH class I/class II as selected immunogenic proteins and designed non-allergenic structures with solubility of 0.650 and immunogenicity score of 0.91. The results of this "in silico" study indicate high specificity and the development of a significant humoral and cellular immune response. It can be concluded that the Hcp and OmpC dual vaccine construct is one of the promising candidates against A. baumannii. The findings of this "in silico" study show excellent specificity and the emergence of a substantial humoral and cellular immune response. This is a computer-based study that needs to be tested in vitro and in vivo to corroborate the conclusions of the vaccine design procedures.

Recent Advances in Antimicrobial Nano-Drug Delivery Systems

Infectious diseases are among the major health issues of the 21st century. The substantial use of antibiotics over the years has contributed to the dissemination of multidrug resistant bacteria. According to a recent report by the World Health Organization, antibacterial (ATB) drug resistance has been one of the biggest challenges, as well as the development of effective long-term ATBs. Since pathogens quickly adapt and evolve through several strategies, regular ATBs usually may result in temporary or noneffective treatments. Therefore, the demand for new therapies methods, such as nano-drug delivery systems (NDDS), has aroused huge interest due to its potentialities to improve the drug bioavailability and targeting efficiency, including liposomes, nanoemulsions, solid lipid nanoparticles, polymeric nanoparticles, metal nanoparticles, and others. Given the relevance of this subject, this review aims to summarize the progress of recent research in antibacterial therapeutic drugs supported by nanobiotechnological tools.

Effects of Imipenem-containing Niosome nanoparticles against high prevalence methicillin-resistant Staphylococcus Epidermidis biofilm formed

We aim to assess the antibacterial and anti-biofilm properties of Niosome-encapsulated Imipenem. After isolating Staphylococcus epidermidis isolates and determining their microbial sensitivity, their ability to form biofilms was examined using plate microtiter assay. Various formulations of Niosome-encapsulated Imipenem were prepared using the thin-film hydration method, Minimum Biofilm Inhibitory Concentration (MBIC) and Minimum Inhibitory Concentration (MIC) were determined, and biofilm genes expression was examined. Drug formulations’ toxicity effect on HDF cells were determined using MTT assay. Out of the 162 separated S. epidermidis, 106 were resistant to methicillin. 87 MRSE isolates were vancomycin-resistant, all of which could form biofilms. The F1 formulation of niosomal Imipenem with a size of 192.3 ± 5.84 and an encapsulation index of 79.36 ± 1.14 was detected, which prevented biofilm growth with a BGI index of 69% and reduced icaD, FnbA, EbpS biofilms’ expression with P ≤ 0.001 in addition to reducing MBIC and MIC by 4–6 times. Interestingly, F1 formulation of niosomal Imipenem indicated cell viability over 90% at all tested concentrations. The results of the present study indicate that Niosome-encapsulated Imipenem reduces the resistance of MRSE to antibiotics in addition to increasing its anti-biofilm and antibiotic activity, and could prove useful as a new strategy for drug delivery.