Physiological Solution Research Articles

Synthesis and Characterization of Alginate Gel Beads with Embedded Zeolite Structures as Carriers of Hydrophobic Curcumin.

Alginate-based beads containing a porous zeolite filler were developed as carriers of bioactive compounds with a hydrophobic nature, such as curcumin (Cur). Curcumin, a natural pigment extracted from the turmeric (Curcuma longa) plant, exhibits antioxidant, anti-inflammatory, anticarcinogenic, and antiviral properties. To enhance the bioavailability of the drug, curcumin needs to be encapsulated in a suitable carrier that improves its dispersibility and solubility. Commercial A-type zeolites (Z5A) were used as curcumin-binding agents and they were immobilized within the alginate gel beads by cross-linking in calcium chloride solution during an extrusion dripping process. The process parameters (alginate and CaCl2 concentrations, needle gauge, collecting distance) were optimized to fabricate beads with good sphericity factor and 1.5-1.7 mm diameter in their hydrated state. The chemical structure of the gel beads was assessed using FTIR spectroscopy, while their thermal stability was evaluated through differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Due to the alginate matrix, the composite Alg/ZA5-Cur beads possess pH-responsive properties. In addition, the gel beads were modified by chitosan (CS) to enhance the stability and control the degradation behavior of the gel matrix. The swelling behavior and the degradation of the beads were analyzed in physiological solutions with different pH values. Results demonstrate the stabilizing and protective effect of the chitosan coating, as well as the reinforcing effect of the zeolite filler. This makes the pH-responsive alginate gel beads good candidates for the delivery of lipophilic drugs to specific inflammatory sites.

Effect of Mo content on the passivation and localized corrosion behavior of laser engineered net shaped (LENS) Co-Cr-Mo alloys in a simulated physiological solution

Effect of Mo content on the passivation and localized corrosion behavior of laser engineered net shaped (LENS) Co-Cr-Mo alloys in a simulated physiological solution

Anticancer Effects of Plasma-Treated Water Solutions from Clinically Approved Infusion Liquids Supplemented with Organic Molecules.

Water solutions treated by cold atmospheric plasmas (CAPs) currently stand out in the field of cancer treatment as sources of exogenous blends of reactive oxygen and nitrogen species (RONS). It is well known that the balance of RONS inside both eukaryotic and prokaryotic cells is directly involved in physiological as well as pathological pathways. Also, organic molecules including phenols could exert promising anticancer effects, mostly attributed to their pro-oxidant ability in vitro and in vivo to generate RONS like O2-, H2O2, and a mixture of potentially cytotoxic compounds. By our vision of combining the efficacy of plasma-produced RONS and the use of organic molecules, we could synergistically attack cancer cells; yet, so far, this combination, to the best of our knowledge, has been completely unexplored. In this study, l-tyrosine, an amino acid with a phenolic side chain, is added to a physiological solution, often used in clinical practice (SIII) to be exposed to plasma. The efficacy of the gas plasma-oxidized SIII solution, containing tyrosine, was evaluated on four cancer cell lines selected from among tumors with poor prognosis (SHSY-5Y, MCF-7, HT-29, and SW-480). The aim was to induce tumor toxicity and trigger apoptosis pathways. The results clearly indicate that the plasma-treated water solution (PTWS) reduced cell viability and oxygen uptake due to an increase in intracellular ROS levels and activation of apoptosis pathways in all investigated cancer cells, which may be related to the activation of the mitochondrial-mediated and p-JNK/caspase-3 signaling pathways. This research offers improved knowledge about the physiological mechanisms underlying cancer treatment and a valid method to set up a prompt, adequate, and effective cancer treatment in the clinic.

USE OF PROBIOTICS IN ALLERGIC RHINITS: A PILOT STUDY

Allergic rhinitis (AR) is a nasal inflammatory disease. It manifests itself with nasal obstruction/blockage, rhinorrhea, itching and sneezing in response to contact with allergens. Its diagnosis is clinical and confirmed with allergy tests. Its treatment may involve antihistamines, topical corticosteroids, as well as immunotherapy, which is considered the only treatment capable of altering the clinical history of the disease. To evaluate the use of probiotics to control allergic rhinitis symptoms. This is a comparative experimental pilot study in which 11 adult employees were evaluated in 4 weeks and, of these, 9 were also evaluated in 8 weeks. Everyone used 0.9% physiological solution, budesonide 200 mcg/day nasally and desloratadine, when necessary. Among the volunteers, 7 also used the combination of probiotics, Lactobacillus helveticus R0052 and Bifidobacterium longum R0175, one capsule a day. There was statistical relevance in the probiotic group for sneezing in the 4-week evaluation and for nasal obstruction in the 8-week evaluation. The results of this comparative pilot study may have been influenced by the small sample size. Even so, it was possible to find data with statistical relevance that confirmed the benefit of using probiotics, mainly to reduce sneezing and nasal obstruction. Despite being a promising form of RA treatment, more studies are needed on the use of probiotics for this purpose.

Silk Fibroin/ZnO Coated TiO2 Nanotubes for Improved Antimicrobial Effect of Ti Dental Implants.

The aim of the present research is to develop a novel hybrid coating for a Ti dental implant that combines nature-inspired biomimetic polymers and TiO2 nanostructures with an entrapped ZnO antimicrobial agent. ZnO was used in other studies to cover the surface of Ti or Ti-Zr to reduce the need of clinical antibiotics, prevent the onset of peri-implantitis, and increase the success rate of oral clinical implantation. We developed an original coating that represents a promising approach in clinical dentistry. The titanium surface was first anodized to obtain TiO2 nanotubes (NT). Subsequently, on the NT surface, silk fibroin isolated from Bombyx mori cocoons was deposited as nanofibers using the electrospun technique. For an improved antibacterial effect, ZnO nanoparticles were incorporated in this biopolymer using three different methods. The surface properties of the newly created coatings were assessed to establish how they are influenced by the most important features: morphology, wettability, topography. The evaluation of stability by electrochemical methods in simulated physiological solutions was discussed more in detail, considering that it could bring necessary information related to the behavior of the implant material. All samples had improved roughness and hydrophilicity, as well as corrosion stability (with protection efficiency over 80%). The antibacterial test shows that the functional hybrid coating has good antibacterial activity because it can inhibit the proliferation of Staphylococcus aureus up to 53% and Enterococcus faecalis up to 55%. All Ti samples with the modified surface have proven superior properties compared with unmodified TiNT, which proved that they have the potential to be used as implant material in dentistry.

Tocolytic Effect of White Pepper (Piper nigrum Linn.) on Isolated Rat Uterine Contraction in vitro

Piper nigrum Linn. (Pepper) is a very well-known spice used for different purposes such as human dietaries, medicine and preservative. In Thai traditional medicine, white pepper is a component of herbal formulas used to treat many disorders including symptoms of dysmenorrhea. It is of interest to investigate the effect of methanolic extract of white pepper (MEWP) on the isolated rat uterus contractions induced by various uterine stimulants and the possible mechanism(s) involved. Strips of uterus were prepared from estrogen-primed female Wistar rats, fixed in the organ bath filled with an appropriate physiological solution with carbogen bubbled continuously at 37 °C. The measurement of isometric tension was then performed using force transducer attached to a polygraph. MEWP was tested its effect on the uterine contraction and found the inhibitory effects on the contraction induced by oxytocin, PGF2α and depolarizing solution. TEA inhibited the uterine relaxing effect of MEWP while glibenclamide had no effects when the uterus was induced to contract with oxytocin. Propranolol abolished the uterine relaxing effect of isoproterenol while it had no effects on the relaxing effect of MEWP. The results suggested that MEWP is likely to be a general uterine relaxant. The effects may be due to the interference on Ca2+ influx into the uterine muscle cells which may involve the opening of KCa channel. The effect was unlikely to occur via the KATP-channel and may not involve the interaction of MEWP on b-adrenergic receptor on the uterine muscle cells. HIGHLIGHTS Methanolic extract of white pepper (MEWP) is likely to be a general uterine relaxant. The uterine relaxing effect of MEWP may involve an inhibition of a rise in intracellular Ca2+ from both Ca2+ influx via plasma membrane of the uterine smooth muscle cell and probably Ca2+ release from internal storage. The effect of MEWP may be mediated mainly through a reduction in Ca2+ influx, possibly through voltage dependent Ca2+ The effect of MEWP may involve with the opening of KCa channel, which may arise from direct action of MEWP on the calcium channel or be a consequence of an increase in [Ca2+]i. The uterine relaxing effect of MEWP is unlikely to be mediated by an activation of β2 –adrenergic receptor. GRAPHICAL ABSTRACT

Triple-layered scaffold containing cisplatin and curcumin applied for cancerous bone regeneration.

Novel drug delivery system was prepared and evaluated as for application in cancerous bone treatment. It had three stacked layers, including a drug-free layer, a cisplatin-loaded layer, and a curcumin-containing layer. Our previously characterized biomaterials, namely Zr-hydroxyapatite (Zr-HA) and alkaline-treated polycaprolactone (modified-PCL), were used as major components of the drug carrier. Polar-polar interactions between cisplatin and Zr-HA were modulated by the modified-PCL included, leading to increase of cisplatin release. Using β-cyclodextrin (β-CD) to entrap curcumin caused improvement of curcumin solubility and release. The 3D-construct was porous with internal interconnected pores according to SEM micrographs. Large amount of apatite was formed and proteins adsorbed on the scaffolds after immersed in physiologic buffer solution and in medium containing fetal bovine serum, respectively. Optimal concentrations of ascorbic acid and triamcinolone were used for induction of bone marrow stromal cells to become osteoblasts by expressing an enzyme marker, e.g., alkaline phosphatase. The prepared scaffolds were considered osteo-conductive and osteo-inductive. The concentrations of cisplatin and curcumin reached the IC50 of SK-ES-1 cells of osteosarcoma and MCF-7 cells of breast adenocarcinoma after 24h and 3days of release, respectively. These cancer cells were more sensitive to the combined cisplatin and curcumin than each of the drugs. Regeneration of new bone and execution of residential cancer cells in defected bone were proposed after replacing the lost bone by this established drug carrier. The assumption needs to be verified in the future using animal models.

Realization of malignant potential of human glioblastoma mitochondria in immunodeficient animals

Purpose. Obtaining extracranial diffuse tumor foci of glioblastoma in Balb/c Nude mice by implantation of mitochondria isolated from human glioblastoma.Material and methods. Human glioblastoma mitochondria were isolated using differential centrifugation in a high speed refrigerated centrifuge. Mitochondrial samples were diluted with 0.9 % NaCl solution to a protein concentration of 3 mg of protein in 0.4 ml of saline. Balb/c Nude mice (N = 6) were intraperitoneally transplanted with freshly isolated glioblastoma mitochondria at the rate of 3 mg of protein per 1 animal in 0.4 ml of physiological solution. Male mice of Balb/c Nude line (N = 4), which were injected once intraperitoneally with 0.4 ml of physiological solution, served as control. All animals were euthanized by guillotine decapitation 17-21 days aſter parenteral implantation of mitochondria isolated from glioblastoma.Results. Specific changes in the spleen structure were revealed (N = 4): the formation of strands of cells resembling glioblastoma multi-forme was observed in multiple fields of vision. The initiation of diffuse growth of glioblastoma cells in the stromal part of the red pulp of the spleen was evidenced by the expression of GFAP and ki-67, which were also recorded in the tumor preparation of the patient with glioblastoma. Morphological examination of the mesentery and lymph nodes revealed multiple areas with atypical cells resembling glioblastoma multiforme, localized in fibrous septa and sinuses. Stained granules with the corresponding immunohistochemical profile, GFAP and ki-6, were clearly defined in the mesentery and lymph node of a Balb/c Nude mouse (N = 6) aſter transplantation of human glioblastoma mitochondria. An additional study of the immunophenotype of cells in the spleen, mesentery, and lymph nodes of Balb/c Nude mice by the generally accepted marker S100 leſt no doubt about the induction of malignant growth aſter transplantation of mitochondria isolated from human glioblastoma.Conclusions. Parenteral implantation of mitochondria isolated from human glioblastoma in male Balb/c Nude mice Might cause the growth and development of extracranial foci of glioblastoma in animals.

A Comparison between Intravenous Ketamine and Magnesium Sulphate for Prevention of Intraoperative Shivering in Patients Undergoing Spinal Anesthesia

Abstract Background Post-anesthetic shivering is a frequent complication of spinal and epidural anesthesia causing many complications intra and post operatively. This randomized controlled study aimed to compare Ketamine versus Magnesium sulphate in prevention of intraoperative shivering after spinal anesthesia. Aim of Work To compare the efficacy and safety of low doses of ketamine versus magnesium sulphate as preventive agents of shivering in patients undergoing spinal anesthesia for surgery. Patients and Methods The current randomized double-blinded clinical trial was conducted in Ain Shams university hospitals. It included 75 patients who underwent diabetic foot debridement surgeries under spinal anesthesia and met the selection criteria. After intrathecal injection, the patients were classified into three groups: Group K who received ketamine 0,5 mg/kg. diluted in a 100 ml of normal saline and given over 15 minutes, prophylactically. Group M received Magnesium sulphate 30 mg/kg. diluted in a 100 ml of normal saline and given over 15 minutes prophylactically. Group P received a 100 ml bolus of physiological solution given over 15 minutes. Results Both Ketamine and Magnesium sulphate showed better results in the control of shivering than the control group (p = 0.035), reduced requirement of pethidine (p = 0.022) and both showed significant effect in delaying the onset of shivering (p = 0.001). The ketamine group had less incidence of shivering, more delayed onset and lesser dose of pethidine required than the Magnesium group but not enough to be statistically significant. Ketamine also showed less incidence of hypotension following spinal anesthesia (p = 0.03) but much more incidence of heavy sedation and hallucinations (p = 0.000) Conclusion Both ketamine and Magnesium sulphate are effective agents in controlling shivering after spinal anesthesia. They reduce the incidence of shivering, delay the onset of shivering if it occurs and reduces the required dose of pethidine to resolve shivering with minimal side effects. Ketamine has a probable protective effect against hypotension after spinal anesthesia.

Treatment of animals with fatty liver disease using a drug based on the seeds of Silybum marianum

Medicinal plants are a source of various therapeutic preparations. Therefore, the aim of our work was to prepare a liposomal drug from extract from the seeds of Silybum marianum (L.) Gaertn., adding tocopherol acetate, lecithin, squalene, and Tween 80. The drug was used on the laboratory animals (rats) intramuscularly to measure the efficacy of treatment of experimentally modeled toxic fatty liver disease. The fatty infiltration of the liver in the rats was caused by tetrachloromethane (ССl4). The efficacy of the liposomal drug based on the extract from S. marianum seeds was studied on 25 animals in which the liver pathology had been caused by 50% oil solution of ССl4, administered in the dose of 5 mL per kg of body weight. The diseased rats were divided into five groups, each consisting five animals. Animals of the four experimental groups – first, second, third, and fourth - received the drug intramuscularly in the doses of 0.05, 0.25, 0.50, and 1.50 mL/kg of body weight three times every two days, respectively. At the same time, the control rats received three-time intramuscular injection of physiological solution in the dose of 0.5 mL/kg of body weight. Treatment of the animals with fatty liver disease by injections of the drug based on the extract from S. marianum seeds normalized the general condition, significantly improved the functions and structure of the liver. Biochemical studies of blood serum of the sick animals after the treatment revealed increase in albumin content, which may suggest reduction of the protein-synthesizing function of the liver. The normalization of the bile-forming and bile-excreting functions of the liver, and also elimination of cholestasis were evidenced by reduced contents of bile acids and total bilirubin and increased total cholesterol in the blood serum of the rats. After treating the animals with the created drug, we saw decrease in the activity of the liver-indicator enzymes (aspartate aminotransferase, alanine aminotransferase, gamma-glutamyltransferase, and glutamate dehydrogenase) in the blood serum, which is a sign of recovery of the structure of hepatocytes and elimination of cytolysis. Histological studies of the liver of the treated rats confirmed the positive effect of the liposomal drug on the organ’s structure. In the future studies, we plan to test this combination of agents in treatment of agricultural and domestic animals with liver pathologies.

Saline bolus for negative contrast perfusion imaging in magnetic particle imaging.

Objective.Magnetic particle imaging (MPI) is capable of high temporal resolution measurements of the spatial distribution of magnetic nanoparticles and therefore well suited for perfusion imaging, which is an important tool in medical diagnosis. Perfusion imaging in MPI usually requires a fresh bolus of tracer material to capture the key signal dynamics. Here, we propose a method to decouple the imaging sequence from the injection of additional tracer material, without further increasing the administered iron dose in the body with each image.Approach.A bolus of physiological saline solution without any particles (negative contrast) diminishes the steady-state concentration of a long-circulating tracer during passage. This depression in the measured concentration contributes to the required contrast dynamics. The presence of a long-circulating tracer is therefore a prerequisite to obtain the negative contrast. As a quantitative tracer based imaging method, the signal is linear in the tracer concentration for any location that contains nanoparticles and zero in the surrounding tissue which does not provide any intrinsic signal. After tracer injection, the concentration over time (positive contrast) can be utilized to calculate dynamic diagnostic parameters like perfusion parameters in vessels and organs. Every acquired perfusion image thus requires a new bolus of tracer with a sufficiently large iron dose to be visible above the background.Main results.Perfusion parameters are calculated based on the time response of the proposed negative bolus and compared to a positive bolus. Results from phantom experiments show that normalized signals from positive and negative boli are concurrent and deviations of calculated perfusion maps are low.Significance.Our method opens up the possibility to increase the total monitoring time of a future patient by utilizing a positive-negative contrast sequence, while minimizing the iron dose per acquired image.

Sodium alendronate is an effective adjunctive therapy for treating periodontitis in male rats treated with anticancer chemotherapy

ObjectivesTo assess sodium alendronate as a local adjunctive therapy for treating experimental periodontitis in male rats treated with chemotherapy. DesignOne-hundred-eighty male rats were randomly divided into two groups (n = 90) based on the systemic treatments: PSS, physiological saline solution; and 5-Fluorouracil, and then, subdivided into three subgroups (n = 30): NT, no treatment; scaling and root planing; and sodium alendronate. Treatments were performed 7 days after induction of experimental periodontitis. Specimens were collected at 14, 22, and 37 days after induction. Alveolar bone level, percentage of bone in the furcation, percentage of non-vital bone in the furcation, histopathologic features, and immunolabeling pattern for tartrate-resistant acid phosphatase (TRAP) and osteocalcin (OCN) were evaluated. ResultsThe lowest amount of alveolar bone and highest amount of non-vital bone was found in group 5-Fluorouracil when no treatment was performed. In animals receiving 5-Flurouracil and subjected to periodontal treatment, adjunctive sodium alendronate resulted in higher percentage of bone in the furcation and higher alveolar bone loss, when compared with scaling and root planing alone. Better structural and cellularity patterns were found in the periodontal tissues when sodium alendronate was used, regardless of systemic treatment. Higher TRAP-expression was found when no treatment was performed. Sodium alendronate didn’t affect the immunolabeling pattern of osteocalcin in the presence of 5-Fluorouracil. ConclusionAdjunctive therapy with local sodium alendronate prevented alveolar bone loss and improved the histopathological features of the periodontal tissues following scaling and root planing in male rats with experimental periodontitis receiving anticancer chemotherapy with 5-Fluorouracil.

Neural targets of the enteric dopaminergic system in regulating motility of rat proximal colon.

In isolated segments of the rat proximal colon, the dopamine reuptake inhibitor GBR 12909 (GBR) causes a dilatation, while the D1-like receptor antagonist SCH 23390 (SCH) induces a tonic constriction, suggesting that neurally released dopamine tonically stimulates enteric inhibitory efferent neurons. Here, the targets of the enteric dopaminergic neurons were investigated. Cannulated segments of rat proximal colon were bathed in physiological salt solution and luminally perfused with 0.9% saline, while all drugs were applied to the bath. Spatio-temporal maps of colonic motility were constructed from video recordings of peristaltic contractions, and the maximum diameter was measured as an index of colonic contractility. GBR (1μM)-induced dilatations of colonic segments were prevented by SCH (5μM), L-nitro arginine (L-NA; 100μM), a nitric oxide synthase inhibitor, or tetrodotoxin (0.6μM). In contrast, constrictions induced by a higher concentration of SCH (20μM) were unaffected by either L-NA or tetrodotoxin. The vasoactive intestinal peptide (VIP) receptor antagonist VIP10-28 (3μM) or P2Y1 receptor antagonist MRS 2500 (1μM) had no effect on either the GBR-induced dilatation or the SCH-induced constriction. In colonic segments that had been pretreated with 6-hydroxydopamine (100μM, 3h) to deplete enteric dopamine, GBR failed to increase the colonic diameter, while SCH was still capable of constricting colonic segments. Enteric dopaminergic neurons appear to project to nitrergic neurons to dilate the proximal colon by activating neuronal D1-like receptors. In addition, constitutively activated D1-like receptors expressed in cells yet to be determined may provide a tonic inhibition on colonic constrictions.

Variation in the Drought Tolerance of Tropical Understory Plant Communities across an Extreme Elevation and Precipitation Gradient.

Little is known about how differences in water availability within the "super humid" tropics can influence the physiology of understory plant species and the composition of understory plant communities. We investigated the variation in the physiological drought tolerances of hundreds of understory plants in dozens of plant communities across an extreme elevation and precipitation gradient. Specifically, we established 58 understory plots along a gradient of 400-3600 m asl elevation and 1000-6000 mm yr-1 rainfall in and around Manu National Park in southeastern Peru. Within the plots, we sampled all understory woody plants and measured three metrics of physiological leaf drought tolerance-turgor loss point (TLP), cuticular conductance (Gmin), and solute leakage (SL)-and assessed how the community-level means of these three traits related to the mean annual precipitation (MAP) and elevation (along the study gradient, the temperature decreases linearly, and the vapor pressure deficit increases monotonically with elevation). We did not find any correlations between the three metrics of leaf drought tolerance, suggesting that they represent independent strategies for coping with a low water availability. Despite being widely used metrics of leaf drought tolerance, neither the TLP nor Gmin showed any significant relationships with elevation or the MAP. In contrast, SL, which has only recently been developed for use in ecological field studies, increased significantly at higher precipitations and at lower elevations (i.e., plants in colder and drier habitats have a lower average SL, indicating greater drought tolerances). Our results illustrate that differences in water availability may affect the physiology of tropical montane plants and thus play a strong role in structuring plant communities even in the super humid tropics. Our results also highlight the potential for SL assays to be efficient and effective tools for measuring drought tolerances in the field.

An extreme value statistics model of heterogeneous ice nucleation for quantifying the stability of supercooled aqueous systems.

The propensity of water to remain in a metastable liquid state at temperatures below its equilibrium melting point holds significant potential for cryopreserving biological material such as tissues and organs. The benefits conferred are a direct result of progressively reducing metabolic expenditure due to colder temperatures while simultaneously avoiding the irreversible damage caused by the crystallization of ice. Unfortunately, the freezing of water in bulk systems of clinical relevance is dominated by random heterogeneous nucleation initiated by uncharacterized trace impurities, and the marked unpredictability of this behavior has prevented the implementation of supercooling outside of controlled laboratory settings and in volumes larger than a few milliliters. Here, we develop a statistical model that jointly captures both the inherent stochastic nature of nucleation using conventional Poisson statistics as well as the random variability of heterogeneous nucleation catalysis through bivariate extreme value statistics. Individually, these two classes of models cannot account for both the time-dependent nature of nucleation and the sample-to-sample variability associated with heterogeneous catalysis, and traditional extreme value models have only considered variations of the characteristic nucleation temperature. We conduct a series of constant cooling rate and isothermal nucleation experiments with physiological saline solutions and leverage the statistical model to evaluate the natural variability of kinetic and thermodynamic nucleation parameters. By quantifying freezing probability as a function of temperature, supercooled duration, and system volume while accounting for nucleation site variability, this study also provides a basis for the rational design of stable supercooled biopreservation protocols.

The Effect of Hypertonic Mineral Solutions on Reparative-Regenerative Processes in a Skin Wound Defect in an Experiment

Background. Skin wound healing is a serious medical problem that is complicated by bacterial infections and requires appropriate care and treatment.
 Objective: to study the effect of a highly mineralized spray solution on the regenerative processes of the skin in a wound defect in an experiment.
 Materials and Methods. The study was conducted under laboratory conditions on 5 adult Chinchilla rabbits (weight 3.2-3.8 kg). A 10x10 cm area of skin on the back was shaved, and skin fragments measuring 2x2.5 cm were symmetrically excised on both sides of the spine at the level of X-XII ribs. A 0.5 ml solution of Staphylococcus aureus culture concentrate prepared in the laboratory of microbiology of the SI “Institute of Traumatology and Orthopedics of NAMS of Ukraine” was applied to the wounds. On the second and subsequent days of the experiment, a highly mineralized spray solution was applied to the experimental wound, while a physiological saline solution was applied to the control wound. On the 3rd and 7th days, a microbiological culture was taken from the wounds. After 7 days, the skin wound defect was taken for histological examination.
 Results. Macroscopically, there was a significant reduction in the area of the wound defect during the first three days of the experiment due to contraction, with a tendency to accelerate in the experimental defects. However, complete closure of the wound did not occur on the 7th day. The results of the cultures confirmed the growth of microbial colonies of Staphylococcus aureus, which visually (growth dynamics, number and size of colonies) did not differ from the biological samples obtained from control and experimental skin defects. Despite the contamination, purulent discharge from the wound was not observed.
 Conclusions. The experiment showed that the use of a highmineralized solution-based agent potentially contributes to regenerative processes in the skin, including angiogenesis and dermal restoration, but other effects, such as antiinflammatory and antibacterial, require further research.

Synthesis of TiO2/rGO composite coatings on titanium alloys with enhanced anticorrosion performance in palmitic acid-incorporated physiological solutions

During plasma electrolytic oxidation (PEO) process, molten oxide is rapidly solidified through arc discharges in order to create in-situ ceramic TiO2 coatings on titanium alloy substrates. PEO coatings made on biomedical titanium alloys may have limited protection efficiency in organic acid-containing biological solutions due to their inherent porosity. In order to elevate the anticorrosion performance of these coatings, a second layer can be applied to the top surface of the PEO coatings to seal the cracks and pores by other surface engineering methods. In current work, the reduced graphene oxide (rGO) nanosheets were electrophoretically deposited on the Ti–6Al–4V substrate involving an intermediate TiO2 oxide layer applied PEO process. Electrochemical measurements in palmitic acid-containing biological media showed that the duplex TiO2/rGO coating has higher compactness and better corrosion performance than simple TiO2 coating. Indeed, the synthesis of the TiO2/rGO coating on the Ti alloy results in a decrease in the corrosion current density (2.19 μA‧cm−2) in comparison with the simple TiO2 coating (9.85 μA‧cm−2) in an acidic media.

In vitro corrosion behavior of the extruded Mg–4Zn–1Mn alloy in different physiological solutions for biomedical applications

The extruded Mg–4Zn–1Mn alloy was prepared and its in vitro corrosion behavior in different physiological solutions of simulated body fluid (SBF), artificial saliva (AS) and artificial urine (AU) was investigated for biomedical applications. The microstructural characterization by optical microscope (OM), X-ray diffractometer (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS) showed that the alloy with an average grain size of approximate 20 ​μm was mainly composed of α-Mg matrix phase along with some MgZn2 and α-Mn precipitates. The results of electrochemical corrosion and immersion corrosion tests revealed a distinct corrosion behavior for the alloy in different solutions with increasing immersion time. The corrosion morphologies were featured with flocculent precipitates in the SBF, flower-like clusters in the AS and columnar crystals in the AU. The alloy exhibited highest corrosion resistance and lowest corrosion rate in the AS compared with the SBF and the AU, which was attributed to the formation of a stable corrosion products layer.

Effects of polyethylene glycol-grafted phospholipid on the anionic magnetite nanoparticles-induced deformation and poration in giant lipid vesicles.

The hydrophilic polymer polyethylene glycol-grafted phospholipid has been used extensively in the study of artificial vesicles, nanomedicine, and antimicrobial peptides/proteins. In this research, the effects of 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine-N- [methoxy (polyethylene glycol)-2000] (abbreviated PEG-DOPE) on the deformation and poration of giant unilamellar vesicles (GUVs)-induced by anionic magnetite nanoparticles (NPs) have been investigated. For this, the size of the NPs used was 18 nm, and their concentration in the physiological solution was 2.00 μg/mL. GUVs were prepared using the natural swelling method comprising 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and PEG-DOPE. The mole% of PEG-DOPE in the membranes were 0, 2, and 5%. The degree of deformation of the GUVs was quantified by the parameter compactness (Com), which is 1.0 for the spherical-shaped GUVs. The value of Com increases with time during the interactions of NPs with GUVs for any concentration of PEG-DOPE, but the rate of increase is significantly influenced by the PEG-DOPE concentration in the membranes. The average compactness increases with the increase of PEG-DOPE%, and after 60 min of NPs interaction, the values of average compactness for 0, 2, and 5% PEG-DOPE were 1.19 ± 0.02, 1.26 ± 0.03 and 1.35 ± 0.05, respectively. The fraction of deformation (Frd) also increased with the increase of PEG-DOPE%, and at 60 min, the values of Frd for 0 and 5% PEG-DOPE were 0.47 ± 0.02 and 0.63 ± 0.02, respectively. The fraction of poration (Frp) increased with the increase of PEG-DOPE, and at 60 min, the values of Frp for 0 and 5% PEG-DOPE were 0.25 ± 0.02 and 0.48 ± 0.02, respectively. Hence, the presence of PEG-grafted phospholipid in the membranes greatly enhances the anionic magnetite NPs-induced deformation and poration of giant vesicles.

Structure and properties of biogenic hydroxyapatite bioceramics modified by graphene-like structures

Today bone tissue engineering is one of the most used technologies for treat bones injure. Materials containing hydroxyapatite and graphene have received much attention recently. The aim of this study was preparation of biogenic hydroxyapatite bioceramics modified by graphene-like structures investigation effect of graphene on the structure and properties of material. Biogenic hydroxyapatite bioceramics modified by graphene-like structures were successfully prepared by chemical vapor deposition (CVD) method. Subsequently, microstructure, composition, specific surface area, skeleton density, resorption rate in physiological solution and cytotoxicity were evaluated. XRD, IR spectroscopy, micro-Raman spectroscopy and SEM proved graphene oxide’s formation on biogenic hydroxyapatite as well as on silica single crystal for comparison. Although the coating of graphene-like structures on biogenic hydroxyapatite bioceramics reduces the specific surface area, it allows to 4 times increase resorption rate of biogenic hydroxyapatite bioceramics in physiological solution and does not affect the overall assessment of the cytotoxicity. MTT assay established non-cytotoxic effect and indicated a high potential of biogenic hydroxyapatite bioceramics modified by graphene-like structures using CVD method for medical application.