L929 Cell Cultures Research Articles

Deposition of HA-GO on ASO modified Ti surface by EPD method and characterization of surface and biological properties of the coating

In this study, the surfaces of titanium (grade 2) substrates were modified by different methods and then coated with a hydroxyapatite-graphene oxide (HA-GO) composite by electrophoretic deposition (EPD). The aim of the study is to improve the surface properties and increase the hydrophilicity of the surface of titanium by different surface treatments. The surface modification processes are as follows: sandblasting (S), acid etching (E), and finally anodic spark oxidation (ASO) on the etched surface. After the surface modification processes, the surface of titanium was coated with HA-GO suspensions (0, 2, 4, and 6 wt% GO) with a voltage value of 20 for 5 minutes by the EPD method. The surface morphology, elemental analysis, contact angle, phase composition, adhesion, biocompatibility, and bioactivity of the produced coatings were examined. Bioactivity analysis was performed in simulated body fluid (SBF) for 14 days. The MTT experiment was conducted with L929 (mouse fibroblast) cell cultures in accordance with the 70% cell viability criterion. As a result of contact angle measurements, it was observed that all samples showed hydrophilic behavior due to the increased surface area after ASO treatment. The contact angle of the sanded surface was 71.03°, whereas the contact angles of the ASO treatment and HA-GO coatings after the coating process were measured below 5 degrees. The bioactivity test results indicated that the surface modified with HA-GO (4 wt%) exhibited the best apatite nucleation outcome. As a result of the analysis with L929 cells, HA, HA-GO (2 wt%), HA-GO (4 wt%) composite coatings showed biocompatible behaviour with 102.17, 76.52, and 80.43% cell viability, respectively. The best result in the adhesion test was reported for HA-GO (4 wt.%) coating with class 5B.

Study of the influence of the extract of pipsissewa on cell cultures

The development of new diuretics of plant origin is an actual direction. Chimaphila umbellata (L.) is a perennial herb with diuretic, astringent, analgesic and other effects; and it can treat various conditions such as edema, dropsy, etc. Pipsissewa herb helps the removal of nitrogenous and chloride salts from the body due to the content of arbutin glycoside, tannins (up to 5 %). The aim. Evaluation of the effect of pipsissewa extract on L929 cell culture. Materials and methods. Cell line L929 (fibroblasts of mouse adipose tissue) was obtained in the low-temperature bank of the Institute of Problems of Cryobiology and Cryomedicine of the National Academy of Sciences of Ukraine. Cells were cultured in DMEM medium (Bio West, France) enriched with 10 % FBS (Lonza, Germany) with 1 % antibiotic-antimycotic (Bio West, France), in a CO2 incubator (Thermo Fisher Scientific, USA) at 37 ºС in an atmosphere with 5 % CO2. Determination of the minimum toxic concentration at which the cells remained alive was evaluated by morphological features (shape, monolayer integrity, adhesion to plastic). The study of the effect of pipsissewa extract on various cell functions was determined by the following methods: the ability to preserve morphological integrity - by the phase-contrast microscopy method, energy exchange - by the MTT test method, pinocytotic function - by the neutral red absorption method, migratory function - by the scratch test method, proliferative activity - by the doubling calculation method population Results. It is proposed to use concentrations of 0.05, 0.02, 0.01, 0.005 % of pipsissewa extract for further research. After carrying out the MTT reaction, the transition of MTT to formazan was confirmed microscopically in the negative control (native cells), at PE concentrations of 0.01 % and below, and the absence of a reaction in the positive control (cells killed by ethanol) at PE concentrations above 0.02 %. When recording the parameters of the NP absorption reaction, it was determined that PE at a concentration of 0.02 % and higher sharply suppresses pinocytotic activity, despite the partial preservation of cell adhesion, reducing the concentration by two times no longer affects mitochondria. A concentration of 0.01 % reduces proliferative activity, and at a concentration of 0.005 %, no difference with the control values ​​was found. Conclusions. When studying the assessment of the effect of pipsisewa extract on L929 cell culture, a toxic effect on these cells was established when added to the culture medium at a concentration above 0.01 %. The toxic effect had a threshold effect. Migratory and proliferative functions were the most sensitive, energy, pinocytosis and preservation of morphological integrity of cells were less sensitive

Exploring the application of poly(1,2-ethanediol citrate)/polylactide nonwovens in cell culturing.

Biomaterials containing citric acid as a building unit show potential for use as blood vessel and skin tissue substitutes. The success in commercializing implants containing a polymer matrix of poly(1,8-octanediol citrate) provides a rationale for exploring polycitrates based on other diols. Changing the aliphatic chain length of the diol allows functional design strategies to control the implant's mechanical properties, degradation profile and surface energy. In the present work, poly(1,2-ethanediol citrate) was synthesized and used as an additive to polylactide in the electrospinning process. It was established that the content of polycitrate greatly influences the nonwovens' properties: an equal mass ratio of polymers resulted in the best morphology. The obtained nonwovens were characterized by surface hydrophilicity, tensile strength, and thermal properties. L929 cell cultures were carried out on their surface. The materials were found to be non-cytotoxic and the degree of porosity was suitable for cell colonization. On the basis of the most important parameters for assessing the condition of cultured cells (cell density and viability, cell metabolic activity and lactate dehydrogenase activity), the potential of PLLA + PECit nonwovens for application in tissue engineering was established.

Synthesis and characterization of amino-functional polyesters composed of lactic acids and serine amino acids

Functional polyesters with good biocompatibility are always important biomaterials. In this study, poly (latide-co-N-trityl serine ester)s (P (LA-co-TSL)s) were synthesized through the copolymerization of lactide (LA) and N-trityl serine lactone (TSL) in toluene under 90 °C with the catalysis of diethylzinc. The molecular weight (Mn) of P (LA-co-TSL) with different TSL molar ratios (4.5%, 8.8%, 25.2%, 41.7% and 100 mol%) ranged from 3.7 kDa to 7.2 kDa with the polydipersity index (PDI) from 1.40 to 1.57. The chemical structure of poly (LA-co-TSL)s was characterized by FTIR, 1H NMR and 13C NMR spectroscopy. As the proportion of TSL in P (LA-co-TSL) increased, the glass transition temperature (Tg) of P (LA-co-TSL) increased gradually, from 56 °C of PLA to 161 °C of Poly (TSL). The initial weitht loss temperature of P (LA-co-TSL) increased as the ratio of TSL increased, from 172 °C of PLA to 230 °C of Poly (TSL). Upon removal of the N-trityl protecting group, amino functional poly (latide-co-serine ester) (P (LA-co-SL)) was realized and confirmd by FTIR and 1H NMR spectra. GPC displayed approximately 19.5% polyester backbone degradation during deprotection with trifluoroacetic acid. DSC analysis illustrated better crystallization properties of the copolyester after amino group deprotection. Using mPEG as an initiator, a new type of block copolymer, mPEG-b-poly (latide-co-N-trityl serine ester)s (mPEG-b-P (LA-co-TSL)s), was obtained. After N-trityl removal, mPEG-b-P (LA-co-TSL) displayed excellent cytocompatibility in L929 cell culture experiments.

The three-dimensional culture of L929 and C2C12 cells based on SPI-SA interpenetrating network hydrogel scaffold with excellent mechanical properties.

Cell-cultured meat, which is obtained by adsorbing cells on the three-dimensional scaffold, is considered a potential solution to animal welfare issues. Edible and safe cell-cultured meat scaffolds are a key part of its research. Soy protein isolate (SPI) hydrogel has a three-dimensional network structure and has been studied for L929 cell culture because of its non-toxicity and biocompatibility. However, the toughness and mechanical properties of SPI hydrogel are not enough to bear the requirements of cell cultivation. In this paper, sodium alginate (SA) was added to SPI hydrogel, and the interpenetrating network (IPN) technology was used to construct SPI-SA IPN hydrogel by transglutaminase and Ca2+ double crosslinking method. SPI-SA IPN hydrogel has excellent mechanical properties, structural stability and biodegradable performance than SPI hydrogel. The bio-compatibility and degradability of L929 and C2C12 cells on SPI-SA IPN hydrogel were studied by cytotoxicity, trypan blue and living/dead cell staining, and the growth law of the hydrogel as a scaffold for cell culture was analyzed. The results showed that L929/C2C12 cells can proliferate normally and adhere in hydrogel and have good bio-compatibility. L929 cells with size about 20-50µm have better adhesion and growth abilities on SPI-SA IPN hydrogel than C2C12 cells with 100-300µm. Therefore, the SPI-SA IPN hydrogel is non-toxic and supports the growth of cells in the pores of the material. This study provides a reference for the application of SPI-SA IPN hydrogels in vitro cell growth.

Antiviral Activity of Double-Stranded Ribonucleic Acid and Interferon Alpha Composition in the Model of Experimental Influenza Infection of Mice

High variability of influenza viruses requires the development of agents for nonspecific resistance stimulation, along with the development of new drugs for prevention and treatment. Among the antiviral drugs, interferons and their inducers are known to exhibit a universally wide spectrum of action. The Institute of Medical Biotechnology, a branch of SRC VB «Vector», Rospotrebnadzor, has developed the technology and obtained pharmaceutical compositions containing an interferon inducer — double stranded ribonucleic acid (dsRNA) from the killer strain of Saccharomyces cerevisiae yeast and recombinant human interferon-alpha-2b (IFN- alpha-2b). The specific antiviral activity of the preparations and synergistic effect of the components within the compositions were shown in L-68 and L-929 cell cultures. The aim of this work was to study antiviral activity of intranasal forms of the pharmaceutical compositions containing yeast dsRNA and recombinant human interferon-alpha-2b in a model of lethal influenza infection in mice. The outbred ICR/CD1 mice were intranasally infected with influenza A/Aichi/2/68 (H3N2) virus. The study compositions were intranasally administered 3 hours before infection with influenza virus, as well as 1 and 3 days post infection. The doses of active components in the administered compositions were as follows: for dsRNA — 2.5 mg/kg, for IFN-alpha-2b — 500 IU/kg, 2500 IU/kg, or 5000 IU/kg. The antiviral activity of the drugs was assessed based on the mortality rate and the average life expectancy of mice. It was shown that a three-time intranasal administration of the composition of dsRNA (2.5 mg/kg) and IFN-alpha-2b (2500 IU) into the infected mice according to therapeutic-prophylactic regimen led to an increase in the rates of survival and average life expectancy of animals, which were comparable to the effect of Tamiflu. The comparison preparations — dsRNA and IFN-alpha-2b — administered intranasally at the same doses and regimen exerted no antiviral effect in this mouse model of viral infection. The data obtained confirm the prospects for further development of new dosage forms of dsRNA and interferons for intranasal application as agents for prevention and treatment of influenza.

A Novel Composite Nano-scaffold with Potential Usage as Skin Dermo-epidermal Grafts for Chronic Wound Treatment

Background: Nano-scaffolds loaded with bioactive compounds such as ZnO nanoparticles (ZnO-NPs), as tissue-engineered artificial skin grafts, can be a suitable substitute for extracellular matrix and greatly contribute to accelerating chronic wound treatment by decreasing the chance of bacterial infection. Methods: Silk fibroin nanofiber was fabricated by using electrospinning and three-dimensional porous hybrids (3DPH) nano-scaffold with composite of sodium alginate/ZnO-NPs solution and silk fibroin electrospun nanofibers by adopting freeze-drying method. Successful configuration of nanofibers and porous nano-scaffolds were confirmed using field emission scanning electron microscopy (FE-SEM). Antimicrobial activity, cell attachment, and cytotoxicity evaluation of scaffolds were performed by employing disk diffusion method, L929 cell culture, and MTT assay, respectively. Results: Antibacterial analysis of 3DPH nano-scaffolds revealed their appropriate antibacterial activity against the Staphylococcus aureus and the Escherichia coli bacteria. Furthermore, the results from cytotoxicity and cell adhesion analyses indicated the appropriate cell attachment, viability, and proliferation on the silk fibroin nanofibers and 3DPH nano-scaffold, which are fundamental for wound healing and skin dermo-epidermal grafts. Conclusions: In sum, silk fibroin nanofiber as an epidermal graft and 3DPH nano-scaffold loaded with ZnO-NPs as a dermal graft were fabricated. Moreover, 1.5% (w/v) concentrations of ZnO-NPs were selected and incorporated into the 3DPH nano-scaffold. Considering the promising results of biological analyses, the nanofibrous and 3DPH nano-scaffolds composite may have been suitable for skin dermo-epidermal grafts and skin regeneration.

Influence of the Photodegradation of Azathioprine on DNA and Cells.

Azathioprine (AZA) is a pharmacologic immunosuppressive agent administrated in various conditions such as autoimmune disease or to prevent the rejection of organ transplantation. The mechanism of action is based on its biologically active metabolite 6-mercaptopurine (6-MP), which is converted, among others, into thioguanine nucleotides capable of incorporating into replicating DNA, which may act as a strong UV chromophore and trigger DNA oxidation. The interaction between azathioprine and DNA, before and after exposure to solar simulator radiation, was investigated using UV-vis spectrometry and differential pulse voltammetry at a glassy carbon electrode. The results indicated that the interaction of AZA with UV radiation was pH-dependent and occurred with the formation of several metabolites, which induced oxidative damage in DNA, and the formation of DNA-metabolite adducts. Moreover, the viability assays obtained for the L929 cell culture showed that both azathioprine and degraded azathioprine induced a decrease in cell proliferation.

Electrodeposition of graphene oxide-hydroxyapatite composite coating on titanium substrate

In this work, graphene oxide (GO)/hydroxyapatite (HA) composite coatings were successfully prepared on titanium substrate by electrophoretic deposition technology. Subsequently, microstructure, phase composition, adhesion strength, hydrophilicity, corrosion resistance, bioactivity, antibacterial activity and biocompatibility of the coating were evaluated. The adhesion strength of coating increased by 76% from 6.46 MPa to 17.81 MPa with 0 wt% GO to 12 wt% GO and the corrosion rate of coating with 8 wt% GO was achieved at the minima of (1.493 × 10-3mm/a). Biomineralization experiment indicated the excellent bioactivity of GO/HA composite coatings. The water contact angle of the composite coatings increased from 20.6°(0 wt% GO) to 38.1°(12 wt%GO). The antibacterial rates of coating with 5 wt% GO was 96.7%, while declined to 25% after thermal treatment. In-vitro L929 cell culture experiments indicated the composite coatings with 5 wt% GO exhibited good biocompatibility.

Immobilization of Gelatin on Fibers for Tissue Engineering Applications: A Comparative Study of Three Aliphatic Polyesters.

Immobilization of cell adhesive proteins on the scaffold surface has become a widely reported method that can improve the interaction between scaffold and cells. In this study, three nanofibrous scaffolds obtained by electrospinning of poly(caprolactone) (PCL), poly(L-lactide-co-caprolactone) (PLCL) 70:30, or poly(L-lactide) (PLLA) were subjected to chemical immobilization of gelatin based on aminolysis and glutaraldehyde cross-linking, as well as physisorption of gelatin. Two sets of aminolysis conditions were applied to evaluate the impact of amine group content. Based on the results of the colorimetric bicinchoninic acid (BCA) assay, it was shown that the concentration of gelatin on the surface is higher for the chemical modification and increases with the concentration of free NH2 groups. XPS (X-ray photoelectron spectroscopy) analysis confirmed this outcome. On the basis of XPS results, the thickness of the gelatin layer was estimated to be less than 10 nm. Initially, hydrophobic scaffolds are completely wettable after coating with gelatin, and the time of waterdrop absorption was correlated with the surface concentration of gelatin. In the case of all physically and mildly chemically modified samples, the decrease in stress and strain at break was relatively low, contrary to strongly aminolyzed PLCL and PLLA samples. Incubation testing performed on the PCL samples showed that a chemically immobilized gelatin layer is more stable than a physisorbed one; however, even after 90 days, more than 60% of the initial gelatin concentration was still present on the surface of physically modified samples. Mouse fibroblast L929 cell culture on modified samples indicates a positive effect of both physical and chemical modification on cell morphology. In the case of PCL and PLCL, the best morphology, characterized by stretched filopodia, was observed after stronger chemical modification, while for PLLA, there was no significant difference between modified samples. Results of metabolic activity indicate the better effect of chemical immobilization than of physisorption of gelatin.

The effect of nisin on the biofilm production, antimicrobial susceptibility and biofilm formation of Staphylococcus aureus and Pseudomonas aeruginosa

ObjectivesStaphylococcus aureus and Pseudomonas aeruginosa were the most common bacteria in nosocomial infections. Different bacteriocins are currently being studied as antibiotics or in conjunction with antibiotics as potential strategies to treat resistant infectious agents. The study aimed to determine nisin's effect on the biofilm production, antimicrobial susceptibility, and biofilm formation of S. aureus and P. aeruginosa.Materials and methodsThe experimental research tested two antibiotic-resistant isolates of S. aureus and P. aeruginosa strains. The experimental study tested two antibiotic-resistant isolates of S. aureus and P. aeruginosa strains. The MIC of bacteriocin nisin was determined using the micro broth dilution method, and crystal violet was used to assess the effect of bacteriocin on the biofilm. In addition, L929 cell culture was used to determine the effectiveness of bacteriocin on the isolate under similar cell conditions. Moreover, the MTT assay was used to and evaluate bacteriocin toxicity. In this study, the software Prism version 9 and Graph pad software were utilized.ResultsThe results of this study reveal that the nisin has different activities at different doses and is considered dose-dependent. At various times and doses, nisin inhibits biofilm formation in S. aureus, and P. aeruginosa isolates. Nisin also showed a decreasing survival of the isolates. Antibiotic-resistant bacteria can be made more vulnerable by nisin. Furthermore, nisin treatment affected the production of virulence factors such as hemolysins in S. aureus and had little or a negative effect on P. aeruginosa virulence factors. This medication stops S. aureus and P. aeruginosa from growing and causes bacterial cell damage.ConclusionsAntibacterial properties of nicin against S. aureus and P. aeruginosa were successfully studied. This bacteriocin stops S. aureus and P. aeruginosa from growing and causes bacterial cell damage or death. Damage to the membrane among the fundamental causes is reduced membrane potential and enzyme inactivation.

Effect of Nanobubble Presence on Murine Fibroblasts and Human Leukemia Cell Cultures.

Nanobubbles can enhance both the proliferation and metabolic activity of microorganisms (mainly bacteria) and the growth of the whole higher organisms such as mice, fish, or plants. The critical fact is that nanobubbles of different gases can affect given cells differently. As animal cell cultures are used in industry and research studies, investigations of their interactions with nanobubbles should be carried out. This study aims to uncover whether the presence of nanobubbles improves the proliferation rate and metabolic activity of L929 fibroblasts and HL60 leukemia cells as exemplary animal cell lines of adherent and non-adherent cells, respectively. The long-term (8-day) cultures of both L929 and HL-60 cells with nanobubble addition to the appropriate medium were carried out. The medium was not exchanged for the whole duration of the culture. Nanobubbles of two gases – oxygen and nitrogen – were dispersed in the appropriate media and then used to culture cells. The density and viability of cells were assessed microscopically while their metabolic activity was determined using PrestoBlue or XTT assays. Additionally, we have performed the analysis of substrate consumption rate during the growth and activity of lactate dehydrogenase. We have shown that nanodispersion of both gases enhances the proliferation rate and metabolic activity of L929. For HL-60 cultures, reference cultures exhibited better viability, cell density, and metabolic activity than those with either oxygen or nitrogen nanobubbles. Obtained results clearly show that nanobubble dispersions of both oxygen and nitrogen positively affect the cultures of L929 while inhibiting the growth of HL-60 cells. We suspect that a similar positive effect would be visible for other adherent cells, similar to L929. Such results are promising for intensifying the growth of animal or human cells in routine cell cultures.

Quality and Purity of L929 Cell Cultures: Isoenzyme Profiles As a Sensitive Marker of Cross-Contamination.

Objective: Inappropriate handling of cells can generate modifications in the genomic DNA. The additional risk is cross-contamination. Isoenzyme analysis with gel agarose electrophoresis is a known, fast, and cheap technique for detection of species-specific isoforms of intracellular enzymes. The aim of the experimental work was to check if variations in the cell growth conditions can affect morphology and/or nuclear anomalies including micronuclei (MN) in the L929 cells; and to define how sensitive and selective is the classic gel agarose electrophoresis for analysis of isoforms of the selected enzymes to detect cross-contamination of L929 cultures with HeLa cells or with the related species, such as CHO-K1 cells, in the case of unavailability of the commercial kits. Methods: The experiments were done with use of the National Collection of Type Cultures clone 929 (L929)-mouse fibroblasts from subcutaneous connective tissue; HeLa-human cervix adenocarcinoma; and CHO-K1-epithelial-like hamster ovary cells. Cell morphology was evaluated with a light/fluorescence microscope. MN were determined with the cytokinesis-block micronucleus assay, and the isoenzyme analysis was performed using gel agarose electrophoresis. Results: As shown, the overgrown cultures result in a significant increase of the MN in the L929 cells. The band patterns for lactate dehydrogenate, glucose-6-phosphate dehydrogenase, or malate dehydrogenase allow identification of the single L929, HeLa, or CHO-K1 cell line and to detect the cross-contamination, even up to 0.4%. Conclusions: There can be no exceptions from the recommended cell culture conditions in the passage scheme. The sensitivity of the gel agarose separation depends on the cells and on the type of enzyme tested and seems to be sufficient in a quick screening of the CHO-K1, L929, or HeLa cell cultures through the possible mutual contamination.

Production and characterization of a coconut oil incorporated gelatin-based film and its potential biomedical application

The influence of coconut oil (CO) on a gelatin-based film was investigated when used as a potential wound dressing material. There is limited study on CO in protein-based wound dressing materials. Therefore, in this study a self-supporting, continuous and homogenous CO incorporated gelatin-based film was formulated and obtained by solution casting method. The influence of CO on physicochemical and thermal properties of gelatin-based film was also determined. Moreover, the effect CO in gelatin films on cell viability and cell migration was analysed with a preliminary cell culture study. Homogenous dispersion of 10% (w/w) CO was obtained in films when 3% (v/w) Tween 80, a surfactant, was incorporated to 20% (w/w) plasticized gelatin film forming solution. Effect of CO on gelatin-based film was observed via phase separation by scanning electron microscopy analysis. Water uptake of gelatin film with no CO, GE film; and 10% (w/w) CO incorporated GE film, GE-CO, were 320% and 210%, respectively, after 3 h in water. Fourier transform infrared spectroscopy analysis showed triglyceride component of CO and increased hydrogen bonding between NH groups of gelatin in GE-CO films. Differential scanning calorimetry results suggested a more ordered structure of GE-CO film due to an increase in melt-like transition temperature and melting enthalpy of GE-CO film. CO content also increased cell viability, assessed by XTT assay since cell viability was approximately 100% when L929 cell culture was incubated with GE-CO of 5–100 μg ml−1. Moreover, GE-CO samples within 5–25 μg ml−1 concentration range, increased proliferation of L929 cells since cell viability was significantly higher than the 100% viable cell culture control (P < 0.05) which is also an indication of efficient healing. However, GE decreased viability of L929 cells significantly at 100–10 μg ml−1 concentration range (P < 0.05) and were toxic at concentrations of 100, 75 and 50 μg ml−1 which decreased ∼50% of the viability of the cells. Scratch Assay to assess in vitro wound healing showed cell migration towards scratch after 24 h as an indication of wound healing only in GE-CO samples. This study showed that, CO could efficiently be added to gelatin-based films for preparation of a primary wound dressing biomaterial which is also demonstrated to have a promising wound healing effect for minor wounds.

About 4-Day Rhythm of Proliferative Activity of L-929 Cells in Culture Correlates with the Intensity of Secondary Cosmic Radiation Fluctuations.

The dynamics of proliferative activity of the L-929 cell culture of mouse fibroblast-like cells in the phase of logarithmic growth was compared with some heliogeophysical parameters (Ap and ULF indexes of geomagnetic activity, vertical component of the interplanetary magnetic field, and intensity of fluctuations of secondary cosmic radiation estimated by the neutron monitoring near the Earth's surface). Among the considered heliogeophysical parameters, only the magnitude of fluctuations of minute-to-minute changes in the neutron monitor indicator reliably and negatively correlates with the rate of cell culture reproduction. Considering that the amplitude of secondary cosmic fluctuations is about 5%, which is 0.1% of the total ray flux, and proliferative activity varies in the range of 30-50%, the probability of a direct biotrophic effect of this physical factor is extremely low. It seems likely that proliferative activity of L-929 cell culture is directly affected by another environmental factor, the marker of which is the intensity of neutron counting rate fluctuations.

Antibiotic resistance alters through iron-regulating Sigma factors during the interaction of Staphylococcus aureus and Pseudomonas aeruginosa

Iron is a limiting factor in such a condition that usually is sequestered by the host during polymicrobial infections of Pseudomonas aeruginosa and Staphylococcus aureus. This study aimed to investigate the interaction of S. aureus and P. aeruginosa, which alters iron-related sigma factors regulation and antibiotic resistance. The antibiotic resistance of P. aeruginosa and S. aureus was investigated in a L929 cell culture model. The expression level of pvdS, hasI (P. aeruginosa sigma factors), and sigS (S. aureus sigma factor) genes was determined using Quantitative Real-Time PCR. pvdS and hasI were downregulated during co-culture with S. aureus, while the susceptibility to carbapenems increased (p-value < 0.0001). Also, there was a direct significant relationship between resistance to vancomycin with sigS. Regarding the findings of the current study, iron-related sigma factors of P. aeruginosa and S. aureus play a role in induction susceptibility to various antibiotics, including carbapenems and vancomycin.

Characterization of undegraded and degraded silk fibroin and its significant impact on the properties of the resulting silk biomaterials

The silk fibroin (SF) regeneration process significantly affects the resulting biomaterials, unfortunately, there has been insufficient study regarding the most suitable regeneration method for SF. In this study, we prepared undegraded SF (uSF) and degraded SF (dSF) by common regeneration methods and studied their difference in detail. The results demonstrated that the degradation degree of SF peptide chain had little influence on the secondary structure and thermal stability of SF materials. While, uSF solution showed higher viscosity and surface tension than dSF solution. The uSF membrane (uSFM) could be elongated approximately 134%, 1.6 times the degraded SF membrane (dSFM). SEM implied that both uSF and dSF existed in aqueous solution as micelles with a diameter of approximately 30 nm. dSF could directly form SF nanoparticles (dSFNPs) when poured into acetone while uSF could only form nanoparticles (uSFNP) with the addition of SDS. Glucose oxidase embedded into dSFM and dSFNP showed high catalytic activities, but uSFNP demonstrated nearly no activity. In addition, the dSFM was more appropriate for L929 cell culture. Considering the obvious difference between the two SF proteins, our results are significant in guiding the application of appropriate SF proteins in tissue engineering materials, bioactive materials, bioink, etc.

The Inhibitory Effect of Capparis Ovata Polysaccharides on Cultured Pterygium Fibroblasts.

Objectives:Pterygium recurrence after removal surgery is an important problem. Polysaccharides obtained from Capparis species have been shown to possess various biological properties, including anti-tumor activity. This study was an investigation of the effect of Capparis ovata polysaccharides on cultured pterygium fibroblasts and a comparison with the effects of mitomycin C (MMC).Methods:Pterygium tissue samples were obtained during excision surgery from 3 patients with primary pterygium, and fibroblasts were isolated. Pterygium fibroblast cultures and L929 cell cultures were treated with different concentrations of MMC and Capparis ovata polysaccharides. Cell proliferation and migration were evaluated.Results:An MTT assay revealed that cell viability decreased with increasing concentrations of Capparis ovata polysaccharides in both cell types. MMC also inhibited the proliferation of both cell types. A scratch-wound assay indicated that both Capparis ovata polysaccharides and MMC molecules reduced proliferation and migration in the pterygium fibroblasts and L929 cells.Conclusion:The in vitro Capparis ovata polysaccharide inhibition of proliferation and migration of pterygium fibroblasts was similar to that of MMC. The results of this study suggested that Capparis ovata polysaccharides may be a valuable candidate drug to treat pterygium.

Investigation of the radiopacity and cytotoxicity of albodent - novel strontium carbonate incorporated calcium silicate based dental cement

Introduction. Calcium silicate (CS) dental cements have numerous clinical indications in dentistry including pulp capping, root end surgery, perforation repair and apexification/apexogenesis treatment. Materials and methods. Novel CS based dental cement with incorporation of SrCO3 radiopacifier named ALBO-DENT was used as an experimental cement material while Portland cement (Aalborg, Denmark) and ProRoot MTA (Tulsa Dental, USA) were used as controls. The radiopacity evaluation was performed using digital Trophy Radiographic system with an intention to precisely determine the minimum of radiopaque agent needed to confer to ISO radiopacity requirement. Thereafter, biocompatibility of material was tested in in vitro conditions in mouse fibrosarcoma L929 cell culture treated with materials? extracts. Cell morphology was observed using phase-contrast microscopy, while cell viability was measured using crystal violet (CV) and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) assays. Results. Radiopacity evaluation revealed that 30%wt addition of SrCO3 was necessary to achieve satisfactory radiopacity (3.45 mm Al). Cytotoxicity analysis using CV and MTT assays revealed that pure extracts of ALBO-DENT presented superior biocompatibility when compared to PC and MTA controls while serial dilutions of experimental cements? extracts as well as that of PC and MTA did not influence L929 cell viability. Conclusions. Novel formulation of CS cement - ALBO-DENT presented satisfactory radiopacity and adequate biocompatibility.

Promote anti-inflammatory and angiogenesis using a hyaluronic acid-based hydrogel with miRNA-laden nanoparticles for chronic diabetic wound treatment

Chronic diabetic wound causes serious threat to human health due to its long inflammatory phase and the reduced vascularization. Herein, we develop a hydrogel system for the treatment of diabetic wound, which can short the inflammatory stage (through the use of ori) and promote the angiogenesis (through the addition of siRNA-29a gene). Based on the Schiff base bonds, the Gel/Alg@ori/HA-PEI@siRNA-29a hydrogel was prepared by mixing oxidized hydroxymethyl propyl cellulose (OHMPC), adipic dihydrazide-modified hyaluronic acid (HA-ADH), oridonin (ori) loaded alginate microspheres (Alg@ori) and siRNA-29a gene-loading hyaluronic acid-polyethyleneimine complex HA-PEI@siRNA-29a (HA-PEI@siRNA-29a) under physiological conditions, which had moderate mechanical strength, appropriate swelling property, impressive stability, and slow release ability of ori and siRNA-29a. Excellent biocompatibility of the prepared hydrogel was also confirmed by in vitro mouse fibroblasts L929 cells culture study. Moreover, in vivo experiments further demonstrated that the prepared Gel/Alg@ori/HA-PEI@siRNA-29a hydrogel not only significantly accelerated the diabetic wound healing, angiogenesis factors (α-SMA and CD31) production, but also inhibited pro-inflammatory factors (IL-6 and TNF-α). In summary, we believe that the prepared hydrogels exhibit great potential for the treatment of chronic diabetic wound.