Synthesis of novel chitosan-Schiff bases nanoparticles for high efficiency Helicobacter pylori inhibition.

Two chitosan Schiff bases were synthesized by condensation of chitosan with 2-(4-formylphenoxy)-N-phenylacetamide and N-(4-bromophenyl)-2-(4-formylphenoxy) acetamide denoted as Cs-SBA and Cs-SBBr, respectively. The molecular structures of the resulting chitosan derivatives were characterized using FTIR and 1HNMR and their thermal properties were investigated by TGA. These derivatives were treated with sodium tripolyphosphate (TPP) to produce Cs Schiff base nanoparticles. The nanoparticles physicochemical properties were determined by FTIR, XRD, TEM, and zeta potential analysis. The antimicrobial action against Helicobacter pylori (H. pylori) was evaluated and the results indicated that the anti-H. pylori activity had minimal inhibitory concentration MIC values of 15.62 ± 0.05 and 3.9 ± 0.03 µg/mL for Cs-SBA and Cs-SBBr nanoparticles (Cs-SBA NPs and Cs-SBBr NPs), respectively. The better biologically active nanoparticles, Cs-SBBr NPs, were tested for their cyclooxygenases (COX-1 and COX-2) inhibitory potential. Cs-SBBr NPs demonstrated COX enzyme inhibition activity against COX-2 (IC50 4.5 ± 0.165 µg/mL) higher than the conventional Indomethacin (IC50 0.08 ± 0.003 µg/mL), and Celecoxib (IC50 0.79 ± 0.029 µg/mL). Additionally, the cytotoxicity test of Cs-SBBr NPs showed cytotoxic effect on Vero cells (CCL-81) with IC50 = 17.95 ± 0.12 µg/mL which is regarded as a safe compound. Therefore, Cs-SBBr NPs may become an alternative to cure H. pylori and prevent gastric cancer.

Synthesis and biological evaluation against H. pylori of chitosan menthone Schiff base hybrid with different types of inorganic nanoparticles.

The production of novel natural medicines for the treatment of Helicobacter pylori (H. pylori) has lately attracted a lot of interest. Some bacterial infections have traditionally been alleviated by terpenes. The present work intended to examine the impact of several chitosan menthone Schiff base nanocomposites on the treatment of H. pylori infection as well as on its anti-inflammatory capacity. Chitosan (Cs) was condensed with menthone with different molar ratios of Cs:menthone (1:0.5, 1:1, and 1:2) to produce chitosan Schiff bases namely; Cs-SB1, Cs-SB2, and Cs-SB3, respectively. Cs-SB3 Schiff base nanocomposites were prepared individually by adding 2%Ag, 2%Se, (1%Ag + 1%Se), and 2%Fe2O3 nanoparticles to produce compounds denoted as Cs-SB-Ag, Cs-SB-Se, Cs-SB-Ag/ Se, and Cs-SB-Fe, respectively. The anti-H. pylori activity of Cs-SB-Se was detected at a minimal inhibitory concentration MIC of 1.9 µg/mL making it the most biologically active compound in our study. Cs-SB-Se nanocomposite was tested for its cyclooxygenases (COX-1 and COX-2) inhibitory potential which demonstrated inhibitory efficacy towards COX enzymes with inhibition value against COX-1 (IC50 = 49.86 ± 1.784 µg/mL) and COX-2 (IC50 = 12.64 ± 0.463 µg/mL) which were less than the well-known Celecoxib (22.65 ± 0.081 and 0.789 ± 0.029 µg/mL) and Indomethacin (0.035 ± 0.001 and 0.08 ± 0.003 µg/mL) inhibitors. The selectivity index SI = 3.94 for tested nanocomposites indicated higher selectivity for COX-1. The cytotoxicity of the Cs-SB-Se nanocomposite was evaluated in Vero cells (CCL-81) and it showed that at a concentration of 62.5 µg/mL, cell viability was 85.43 %.

Chitosan Schiff bases-based polyelectrolyte complexes with graphene quantum dots and their prospective biomedical applications.

Chitosan (Cs) bis-aldehyde Schiff base derivatives were synthesized by condensation of Cs with three bis-aldehydes namely; butane-1,4-diyl bis(4-formylbenzoate), N,N'-(butane-1,4-diyl)bis(2-(4-formylphenoxy)acetamide) and 4,4'-(butane-1,4-diylbis(oxy))dibenzaldehyde. The prepared Cs derivatives were blended with carboxymethyl chitosan(CMC) and graphene quantum dots (GQDs) to produce semi-IPNs polyelectrolyte complexes (PECs). and characterized with respect to their molecular structure and physio-chemical properties. The antibacterial activity against H. pylori (and in vitro Inosine 5'-monophosphate dehydrogenase IMPDH inhibitory assay) was evaluated. Additionally, a preliminary in vitro assessment for wound healing was performed against PECs in which wound closure percentages, and rates were investigated indicating an accelerated wound healing compared with untreated cells. The PEC based on Schiff base PEC containing amide linkage showed the highest wound healing ability. A minimal inhibitory concentration (MIC) was obtained for the PEC sample containing Cs Schiff base derived from 4,4'-(butane-1, 4-diylbis(oxy))dibenzaldehyde at a dose of 0.98 µg/ml inhibiting H. pylori growth by 100%. Additionally, the selected above-mentioned compound was selected to test its inhibitory activity against the HpIMPDH enzyme in addition to its selectivity towards the hIMPDH2 enzyme and was found to have promising activity against the HpIMPDH enzyme with IC50 value of 0.65 µM, and to be safer and less active against the hIMPDH2 enzyme with IC50 > 10 µM, reflecting its selectivity.

Vanillin attenuates thioacetamide-induced renal assault by direct and indirect mediation of the TGFß, ERK and Smad signalling pathways in rats.

Inflammation and fibrosis are two pathological features of chronic kidney disease (CKD). Renal fibrosis is considered to be one of the most important conditions, as it may be the result of excessive extracellular matrix protein production and deposition, or prolonged exposure to nephrotoxic substances or drugs. Unfortunately, no suitable therapies or medications are currently available to prevent renal fibrosis. We conducted this study for the evaluation of the protective potential of vanillin by reversing TAA (250 mg/kg TAA for 6 weeks) induced renal injury in rats. The concentrations of the proteins tumour necrosis factor alpha (TNFα), interleukin-6 (IL-6), extracellular signal regulated kinase 1/2 (Erk1/2), and transforming growth factor beta-1 (TGF-ß1) in kidney tissues were assessed using ELISA. Kidney Injury Molecule-1 (KIM-1) and mothers against decapentaplegic homologue 2, 3 (SMAD 2, 3) expressions were evaluated using real time PCR. We also estimated the expression of α-smooth muscle actin (α-SMA) using immunohistochemistry. Treatment with vanillin (100 mg/kg) significantly ameliorated kidney Injury and improved the kidney function. Vanillin treatment also significantly decreased the malondialdehyde (MDA) content, and elevated glutathione peroxidase (GPx) and catalase (CAT) activities in kidney tissues. Vanillin also reduced α-SMA renal expression and TNFα, IL-6, TGF-ß1, and Erk1/2 renal levels. Vanillin significantly decreased the expression of the genes encoding KIM-1 and SMAD 2, 3 and ameliorated histological abnormalities in kidney architecture. Our molecular docking findings showed that vanillin has a good binding mode inside TGF-ß type I receptors (ALK5) biding site.

Chitosan-based delivery systems for plants: A brief overview of recent advances and future directions.

Chitosan has been termed as the most well-known among biopolymers, receiving widespread attention from researchers in various fields mainly, agriculture, food, and health. Chitosan is a deacetylated derivative of chitin, mainly isolated from waste shells of the phylum Arthropoda after their consumption as food. Chitosan molecules can be easily modified for adsorption and slow release of plant growth regulators, herbicides, pesticides, and fertilizers, etc. Chitosan as a carrier and control release matrix that offers many benefits including; protection of biomolecules from harsh environmental conditions such as pH, light, temperatures and prolonged release of active ingredients from its matrix consequently protecting the plant's cells from the hazardous effects of burst release. In the current review, tends to discuss the recent advances in the area of chitosan application as a control release system. Also, future recommendations will be made in light of current advancements and major gaps.

Synthesis, characterization and antimicrobial activity of a novel chitosan Schiff bases based on heterocyclic moieties.

Three heteroaryl pyrazole derivatives; namely 1-phenyl-3-(thiophene-2-yl)-1H-pyrazole-4-carbaldehyde, 1-phenyl-3-(furan-2-yl)-1H-pyrazole-4-carbaldehyde and 1-phenyl-3-(pyridine-3-yl)-1H-pyrazole-4-carbaldehyde were synthesized and reacted with chitosan to form Schiff bases of chitosan. All newly synthesized compounds have been characterized by solubility tests, elemental analysis, spectral (FTIR, 1H NMR) analyses, thermogravimetric analysis and X-ray diffraction (XRD). The Schiff bases were screened for their biological activity against gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), gram-positive bacteria (Staphylococcus aureus and Streptococcus mutans) and fungi (Asperagillus fumigatus and Candida albican). The results indicated that the antimicrobial activity was dependent on the type of the Schiff base moiety. Cytotoxicity of the prepared chitosan derivatives was evaluated by MTT assay and the results indicated the absence of cytotoxic activity.

Trauma video review utilization: A survey of practice in the United States.

INTRODUCTION: Trauma video review (TVR) for quality improvement and education in the United States has been described for nearly three decades. The most recent information on this practice indicated a declining prevalence. We hypothesized that TVR utilization has increased since most recent estimates. METHODS: We conducted a survey of TVR practices at level I and level II US trauma centers. We distributed an electronic survey covering past, current, and future TVR utilization to the Eastern Association for the Surgery of Trauma membership. RESULTS: 45.0% of US level I and level II trauma centers completed surveys. 71/249 centers (28.5%) had active TVR programs. The use of TVR did not differ between level I and level II centers (28.8% vs. 27.8%, p = 0.87). Respondents using TVR were overwhelmingly positive about its perception (median score 8, [IQR 6-9]; 10 = 'best') at their institutions. CONCLUSIONS: TVR use at Level I centers has increased over the past decade. Increased TVR utilization may form the basis for multicenter studies comparing processes of care during trauma resuscitation.

Current advancements in chitosan-based film production for food technology; A review.

Chitosan is obtained from chitin, which could be considered to be the most abundant polymer after cellulose. Owing to these properties, chitosan alone or chitosan-based composite film production is attaining huge attention in terms of applications from researchers and industrialists coming from divergent fields. To enhance the biological (mainly antimicrobial and antioxidant) and physiological (mainly mechanical, thermal and barrier) attributes of the chitosan-based films, a vast medley of plant extracts and supporting polymers has been blended into chitosan films. Considering the up to date literature reports based on chitosan film production and applications, it can be stated that still, the research ratio is low in this field. Chitosan blend/composite films with specific properties (superhydrophobicity, excellent mechanical strength, acceptable barrier properties) can be produced only for specific applications in food technology. In the current review, we tried to summarize the advancements made in the last 5-7 years in the field of chitosan film technology for its application in the food industry.

Topical blood stopper agents during adenoid surgery in young children; a prospective randomized controlled trial.

OBJECTIVE: To investigate the safety and efficacy of two topical blood stopper modulators; Ankaferd blood stopper (ABS) and feracrylum 1% solution (FS) during adenoid surgery. STUDY DESIGN: Prospective randomized trial. METHODS: Two hundred and twenty five consecutive pediatric adenoid patients aged from 9 months to 2 years old were studied. Patients were randomly allocated into two haemostatic groups; (ABS, FS) and normal saline (control group). RESULTS: ABS and FS groups showed a significantly less intra operative blood loss (16.4 ± 2.6/22 ± 6.2), operative time (9.31 ± 1.9/11.2 ± 1.6 min), use of cautery (10.6/25.3%), postoperative analgesics (3 ± 1.1/3.8 ± 1.2), duration to return normal diet (2.4 ± 1.2/3.9 ± 0.9) and operating theatre cost (233 ± 48$ and 279 ± 40$) than the control group. CONCLUSION: AFS and FS are easy, safe, and reliable topical haemostatic modulators that could be used in adenoid surgery.

Synthesis and characterization of some acyl thiourea derivatives of chitosan and their biocidal activities.

Three acyl derivatives of chitosan (CS) with different side chains were synthesized and their structures were characterized. Their swelling behavior was investigated. The antifungal behavior of these chitosan derivatives was investigated in vitro on the mycelial growth, sporulation and germination of conidia or sclerotia of the sugar-beet pathogens, Rhizoctonia solani K"uhn (AG2-2) and Sclerotium rolfsii Sacc. All the prepared derivatives had a significant inhibiting effect on the different stages of development on the germination of conidia or sclerotia of all the investigated fungi. In the absence of chitosan and its derivative, R. solani exhibited the fastest growth of the fungi studied.

Chitosan based edible films and coatings: a review.

Chitosan is a biodegradable biocompatible polymer derived from natural renewable resources with numerous applications in various fields, and one of which is the area of edible films and coatings. Chitosan has antibacterial and antifungal properties which qualify it for food protection, however, its weak mechanical properties, gas and water vapor permeability limit its uses. This review discusses the application of chitosan and its blends with other natural polymers such as starch and other ingredients for example essential oils, and clay in the field of edible films for food protection. The mechanical behavior and the gas and water vapor permeability of the films are also discussed. References dealing with the antimicrobial behavior of these films and their impact on food protection are explored.

Preincisional infiltration and intraperitoneal instillation of levobupivacaine 0.25% for management of early postoperative pain following laparoscopic ovarian drilling.

AIM: To assess the effectiveness of combined preincisional local infiltration (at trocar sites) and intraperitoneal instillation of levobupivacaine 0.25% for the management of early postoperative pain following laparoscopic ovarian drilling. MATERIALS AND METHODS: This is a prospective randomized controlled observer-blinded study. The study included 106 infertile patients with the diagnosis of polycystic ovary syndrome (PCOS) who were scheduled to undergo diagnostic laparoscopy and laparoscopic ovarian drilling (LOD) during the period from November 2009 to February 2012 at TAIBA Hospital in Kuwait. Patients were randomly allocated to two groups of 53 patients each. Group I comprised patients who received preincisional local infiltration and intraperitoneal instillation levobupivacaine 0.25%. Patients in group II received equal volumes of normal saline 0.9% (NS) at the same sites. The primary outcome measures were visual analog scale pain scores and postoperative analgesic consumption. RESULTS: Postoperative average VAS pain scores, i.m. pethidine consumption and i.v. paracetamol consumption during the first 24 h were highly significantly lower in the levobupivacaine group compared to the NS group (P<0.01). This technique was also associated with significantly higher overall patient satisfaction, shorter hospital stay and more rapid resumption of normal activity (P<0.01) without any significant adverse events. CONCLUSION: The combination of preincisional local infiltration and intraperitoneal instillation of levobupivacaine 0.25% was found to substantially reduce postoperative pain and the consumption of postoperative analgesics during the first 24 h; and shorten hospital stay and time to resume normal activities after LOD. It was also associated with a very high overall patient satisfaction without any significant adverse events.

Neuraxial analgesia versus intravenous remifentanil for pain relief in early labor in nulliparous women.

OBJECTIVE: To assess if there is a difference in duration of labor, the mode of delivery, average Visual Analog Scale (VAS) pain scores, maternal overall satisfaction with analgesia, side effects and neonatal outcomes in nulliparous women who received early labor analgesia with either epidural, patient-controlled IV analgesia (PCIA) with remifentanil or combined spinal-epidural (CSE) techniques. STUDY DESIGN: This is a prospective randomized interventional study. SUBJECTS AND METHODS: The study included 1,140 healthy nulliparous women (with term, singleton pregnancies) early in labor, requesting labor analgesia, during the period from September 2009 to August 2011 at TAIBA Hospital in Kuwait. The participants were randomized to receive either epidural analgesia (Group I), or PCIA with remifentanil (Group II) or CSE analgesia (Group III). The primary outcome was the rate of cesarean delivery. RESULTS: CSE analgesia was associated with a statistically highly significant decrease in labor duration (from analgesia to vaginal delivery), duration of latent and active phases of the first stage, and duration of the second stage of labor, average VAS pain scores, and a highest maternal overall satisfaction score with analgesia (P<0.01) as compared to epidural analgesia or PCIA with remifentanil. CONCLUSION: In terms of labor duration, average VAS pain scores, and maternal overall satisfaction score with analgesia, CSE analgesia is superior to that provided by epidural analgesia or PCIA with remifentanil for pain relief in early labor in nulliparous women. However, there were no differences in the mode of delivery, side effects or neonatal outcomes between the three techniques.

Chitosan based nanofibers, review.

Chitin and chitosan are natural polymers with a huge potential in numerous fields, namely, biomedical, biological, and many industrial applications such as waste water treatment due to the fact that they can absorb and chelate many metal cations. Electrospinning is a growing field of research to produce submicron fibers with promising applications in biomedical fields like tissue engineering scaffolds and wound healing capabilities. Both chitin and chitosan polymers were found to be hard to electrospun, however, many researchers manage to produce nano-fibers using special solvents; for example, 90% acetic acid was found to reduce the surface tension making electrospinning feasible. Mixtures of organic acids were also experimented to produce homogenous and uniform fibers. Bigger attention was given to electrospinning of their soluble derivatives such as dibutyryl and carboxymethyl chitin. More derivatives of chitosan were investigated to produce nano-fibers such as hexanoyl, polyethyleneglycol, carboxymethyl, and a series of quaternized chitosan derivatives. The obtained nano-fibers were found to have much better qualities than normal chitosan fibers. Several polymer blends of chitin/chitosan with many commercial polymers were found to be amenable for electrospinning producing uniform beads free fibers. The review surveys the various approaches for successful electrospinning of chitin, chitosan, their derivatives, and blends with several other polymers.

Optimizing the surgical field in pediatric functional endoscopic sinus surgery: a new evidence-based approach.

OBJECTIVES: To conduct the first prospective randomized controlled study 1) evaluating the possibility of improving the quality of the operative field and to provide a bloodless functional endoscopic sinus surgery (FESS) in children through total intravenous anesthesia (TIVA) using remifentanil combined with propofol, and 2) testing the safety and efficacy of remifentanil in propofol-TIVA in inducing controlled hypotension in children at a target mean arterial blood pressure of 50 mm Hg. STUDY DESIGN: Randomized controlled trial. SETTING: General hospital. SUBJECTS AND METHODS: Seventy children underwent FESS under hypotensive general anesthesia with equal randomization into two groups. Group I received TIVA with remifentanil, whereas group II had balanced anesthesia (BA) with esmolol. Heart rate, blood pressure, operative time, blood loss, and quality of the surgical conditions were recorded. RESULTS: Intraoperative blood loss in the TIVA group was less than in the BA group. The quality and dryness of the surgical field in both the visual analogue scale and the six-point scale was significantly better in the TIVA group than in the BA group. Hypotension was sustained at the target mean arterial blood pressure of 50 mm Hg in the two groups, without any significant difference. CONCLUSION: Improving the quality of the surgical field and providing a bloodless FESS in children is attainable with TIVA. TIVA using a combination of remifentanil and propofol is superior to BA, even with the use of additional potent hypotensive agents such as esmolol. Both techniques are safe and effective in inducing controlled hypotension in children at a target mean arterial blood pressure of 50 mm Hg.

Surface active properties of chitosan and its derivatives.

This review discusses the definition of surface active agents and specifically natural polymeric surface active agents. Chitosan by itself was found to have weak surface activity since it has no hydrophobic segments. Chemical modifications of chitosan could improve such surface activity. This is achieved by introducing hydrophobic substituents in its glucosidic group. Several examples of chitosan derivatives with surfactant activity have been surveyed. The surface active polymers form micelles and aggregates which have enormous importance in the entrapment of water-insoluble drugs and consequently applications in the controlled drug delivery and many biomedical fields. Chitosan also interacts with several substrates by electrostatic and hydrophobic interactions with considerable biomedical applications.

Extraction and characterization of chitin and chitosan from local sources.

Chitin has been extracted from six different local sources in Egypt. The obtained chitin was converted into the more useful soluble chitosan by steeping into solutions of NaOH of various concentrations and for extended periods of time, then the alkali chitin was heated in an autoclave which dramatically reduced the time of deacetylation. Chitin from squid pens did not require steeping in sodium hydroxide solution and showed much higher reactivity towards deacetylation in the autoclave that even after 15 min of heating a degree of deacetylation of 90% was achieved. The obtained chitin and chitosan were characterized by spectral analysis, X-ray diffraction and thermo gravimetric analysis.