Rheological Characterization of Genipin-Based Crosslinking Pigment and O-Carboxymethyl Chitosan-Oxidized Hyaluronic Acid In Situ Formulable Hydrogels.

The aim of this study was to develop a material capable of rapidly absorbing bodily fluids and forming a resilient, adhesive, viscoelastic hydrogel in situ to prevent post-surgical adhesions. This material was formulated using O-carboxymethyl chitosan (O-CMCS), oxidized hyaluronic acid (OHA), and a crosslinking pigment derived from genipin and glutamic acid (G/GluP). Both crosslinked (O-CMCS/OHA-G/GluP) and non-crosslinked hydrogels (O-CMCS/OHA) were evaluated using a HAAKE™ MARS™ rheometer for their potential as post-surgical barriers.

Efficacy and feasibility of a novel semi-facial respirator with chitosan nanoparticles on the incidence of SARS-CoV-2 infection in healthcare professionals: randomized controlled trial.

Background: Evidence suggests that semi-facial respirators provide protection against contamination in high-risk environments, although the COVID-19 pandemic called for greater protection and viral inactivation capacity. Thus, the aim of this study was to investigate the efficacy of a novel semi-facial respirator containing chitosan nanoparticles, compared with a conventional N95 respirator on the incidence of laboratory-confirmed SARS-CoV-2 in healthcare professionals. The secondary outcomes were influenza infection, usability and comfort.

Analysis of Tissue Repair of a New Cement Based on Calcium and Strontium Aluminates: A Triple-Blinded, Randomized, Controlled Trial in an Animal Model.

Objective:  The focus of this triple-blind randomized study was to evaluate the biocompatibility of a new root canal filling sealer (RCFS) based on tristrontium aluminate and dodecacalcium hepta-aluminate in living tissue.

Material And Methods:  Forty-five Wistar rats () were divided into three groups: control (polyethylene), sealer (Bio-C Sealer, Londrina, PR, Brazil), and experimental (tristrontium aluminate and dodecacalcium hepta-aluminate). The tissues were analyzed under an optical microscope to assess different cellular events at different time intervals (7, 15, and 30 days).

A novel N95 respirator with chitosan nanoparticles: mechanical, antiviral, microbiological and cytotoxicity evaluations.

Background: It is known that some sectors of hospitals have high bacteria and virus loads that can remain as aerosols in the air and represent a significant health threat for patients and mainly professionals that work in the place daily. Therefore, the need for a respirator able to improve the filtration barrier of N95 masks and even inactivating airborne virus and bacteria becomes apparent. Such a fact motivated the creation of a new N95 respirator which employs chitosan nanoparticles on its intermediate layer (SN95 + CNP).

Physicochemical, Morphological, and Cytotoxic Properties of Brazilian Jackfruit () Starch Scaffold Loaded with Silver Nanoparticles.

Due to the physical, thermal, and biological properties of silver nanoparticles (AgNPs), as well as the biocompatibility and environmental safety of the naturally occurring polymeric component, polysaccharide-based composites containing AgNPs are a promising choice for the development of biomaterials. Starch is a low-cost, non-toxic, biocompatible, and tissue-healing natural polymer. The application of starch in various forms and its combination with metallic nanoparticles have contributed to the advancement of biomaterials.

Chitosan/Gelatin Scaffolds Loaded with Extract as Potential Skin Tissue Engineering Materials.

This work aimed to develop chitosan/gelatin scaffolds loaded with ethanolic extract of (EEJM) to evaluate the influence of its content on the properties of these structures. The scaffolds were prepared by freeze-drying, with different EEJM contents (0-10% (/)) and crosslinked with genipin (0.5% (/)).

Development of Gelatin/Misoprostol Compounds for Use in Pregnancy Failures.

Early abortion is one of the most common complications during pregnancy. However, the frequent handling of the genital region, more precisely the vagina, which causes discomfort to patients in this abortion process due to the frequency of drug insertion, as four pills are inserted every six hours, has led to the search for alternatives to alleviate the suffering caused by this practice in patients who are already in a shaken emotional state. Hence, this work aimed to develop composites of gelatin and misoprostol, using a conventional single-dose drug delivery system.

Brushite bone cement containing polyethylene glycol for bone regeneration.

Background: Bone cements aid in bone regeneration; however, if the handling time is not well established for the material to harden, complications may arise.

Objective: This work investigates the effect of using polyethylene glycol (PEG) and characterize it in brushite bone cement in order to obtain desirable handling times as well as its regeneration in vivo to analyse if addition of this polymer may significantly modify its properties.

Methods: PEG 4000 was synthesised with wollastonite by phosphorization reaction in order to form brushite which was further cured by oven drying.

Surface Bioactivation of Polyether Ether Ketone (PEEK) by Sulfuric Acid and Piranha Solution: Influence of the Modification Route in Capacity for Inducing Cell Growth.

The aim of this study was to promote bioactivity of the PEEK surface using sulfuric acid and piranha solution. PEEK was functionalized by a sulfuric acid treatment for 90 s and by piranha solution for 60 and 90 s. Chemical modification of the PEEK surface was evaluated by infrared spectroscopy, contact angle analysis, cytotoxicity, cell adhesion and proliferation.

Biocompatible Sulphonated PEEK Spheres: Influence of Processing Conditions on Morphology and Swelling Behavior.

This work aimed to develop and evaluate the influence of processing variables on the morphology and swelling of sulfonated poly(ether ether ketone) (SPEEK) spheres for possible applications as a biomaterial. We used the drip method to obtain spheres with the polymer starting solutions SPEEK-6 (/: 6%) and SPEEK-10 (/: 10%), drip rates (20 and 30 mL/h), and drip heights (5 and 10 cm) in experimental planning. The samples were characterized by Fourier-transform infrared spectroscopy (FTIR), optical microscopy (OM), the absorption capacity of phosphate-buffered saline (PBS) by swelling (%), and statistical analysis of data through Design of Experiments (DOE).

In vivo Hemostatic Activity of Jatropha mollissima: A Triple-Blinded, Randomized, Controlled Trial in an Animal Model.

Objective: The objective of this study was to evaluate the hemostatic activity of the sap from (Pohl) Baill. in rats.

Materials And Methods: Twenty-four Wistar rats were randomized into four groups ( = 6): the JM25 and JM40 groups were treated with ethanolic extract from the sap of , in a concentration of 25 and 40 mg·mL, respectively; the MO group was treated with Monsel's solution and the control group SC with a 0.

Chitosan Woven Meshes: Influence of Threads Configuration on Mechanical, Morphological, and Physiological Properties.

This study aimed to develop meshes from the weaving of mono- and multifilament wet-spun chitosan (CS), for possible biomedical applications. In the wet-spinning process, CS solution (4% /) was extruded in a coagulation bath containing 70% sodium hydroxide solution (0.5 M), and 30% methanol was used.

Progress in the Development of Chitosan Based Insulin Delivery Systems: A Systematic Literature Review.

Diabetes mellitus is a chronic disease that is considered a worldwide epidemic, and its control is a constant challenge for health systems. Since insulin had its first successful use, scientists have researched to improve the desired effects and reduce side-effects. Over the years, the challenge has been to increase adherence to treatment and improve the quality of life for diabetics by developing an insulin delivery system.

Chemodiversity and Antibacterial Activity of the Essential Oil of Leaves of Croton argyrophyllus.

The Croton argyrophyllus leaf essential oil has anti-inflammatory, antioxidant, cytotoxic among other activities. However, there are chemical composition variations in the literature. This work reports the first study of the intraspecific chemical variation of C.

Injectable bone substitute based on chitosan with polyethylene glycol polymeric solution and biphasic calcium phosphate microspheres.

We described a method to produce an injectable bone substitute consisting of a solid and liquid phase, this solid was formed using the coacervation method consisting of a mixture of Hydroxyapatite (HAp) and beta-Tricalcium Phosphate (β-TCP) which the sodium alginate - precursor - was removed during sinterization. The biphasic calcium phosphate microspheres had varying size distributions depending on the flow rate and these microspheres were mixed with a polymeric solution, chitosan and polyethylene glycol, and depending on the ratio of these phases, the injectability results varied. Nonetheless, the force required for complete removal will not disrupt the accuracy of injection into the bone defect while the biomaterial exhibited no cytotoxicity with promising results from in vivo using tibia bone defect in rabbits at 30 and 60 days whereas bone repair was more intense and accentuated with the usage of the biomaterial, and was gradually absorbed during the evaluated periods.

Effect of chitosan and Dysphania ambrosioides on the bone regeneration process: A randomized controlled trial in an animal model.

The focus of this triple-blind study was on evaluating the effect of chitosan combined with Dysphania ambrosioides (A) extract on the bone repair process in vivo. In total, 60 male Wistar rats (Rattus norvegicus albinus) weighing between 260 and 270 g were randomly selected for this study and distributed into four groups (n = 15). Group C (chitosan), Group CA5 (chitosan + 5% of D.

Chitosan/Essential Oils Formulations for Potential Use as Wound Dressing: Physical and Antimicrobial Properties.

Film-forming emulsions and films, prepared by incorporating different concentrations of clove essential oil (CEO) and melaleuca essential oil (MEO) into chitosan (CS) were obtained and their properties were evaluated. Film-forming emulsions were characterized in terms of qualitative assessment, hydrogen potential and in vitro antibacterial activity, that was carried by the agar diffusion method, and the growth inhibition effects were tested on the Gram-positive microorganism of , Gram-negative microorganisms of , and against isolated fungi such as . In order to study the impact of the incorporation of CEO and MEO into the CS matrix, the appearance and thickness of the films were evaluated.

N-Acetyl-D-Glucosamine-Loaded Chitosan Filaments Biodegradable and Biocompatible for Use as Absorbable Surgical Suture Materials.

The aim of this study was to prepare chitosan (CS) filaments incorporated with N-acetyl-D-Glucosamine (GlcNAc), using the wet spinning method, in order to combine the GlcNAc pharmacological properties with the CS biological properties for use as absorbable suture materials. The filaments were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), uniaxial tensile testing, in vitro biodegradation, and through in vitro drug release and cytotoxicity studies. It was observed that the addition of GlcNAc did not alter the morphology of the filaments.

Optimization of Epoxy Resin: An Investigation of Eggshell as a Synergic Filler.

Epoxy resin based on bisphenol A diglycidyl ether/anhydride methyl tetrahydrophthalic/2,4,6-tris(dimethylaminomethyl)phenol (DGEBA/MTHPA/DEH 35) was produced by magnetic stirring; chicken eggshell (ES) was added as cure improver. Thermal stability, cure parameters, mechanical properties, and fracture surface were investigated by thermogravimetry (TGA), differential scanning calorimetry (DSC), tensile experiments, and scanning electron microscopy (SEM). In general, the addition of ES slightly decreased the thermal stability, being T 5% lower than that of the reference sample.

Physicomechanical and thermal analysis of bulk-fill and conventional composites.

The aim of this study was to evaluate the degree of conversion (DC) and the thermal stability of bulk-fill and conventional composite resins. Eleven composite resin samples were prepared to evaluate the DC, Vickers microhardness (VMH), mass and residue/particle loss, glass transition temperature (Tg), enthalpy, and linear coefficient of thermal expansion (CTE) using infrared spectroscopy (FTIR), microdurometer analyses, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dilatometry (DIL). The data were subjected to statistical analysis, with a significance level of 95%.

Synthesis and Preparation of Chitosan/Clay Microspheres: Effect of Process Parameters and Clay Type.

This work aimed to prepare chitosan/clay microspheres, by the precipitation method, for use in drug carrier systems. The influence of the process parameters, particularly two airflows of the drag system (2.5 and 10 L·min) on the microspheres physical dimensions and properties, such as microstructure, degree of swelling and porosity were evaluated.

Physicomechanical characterization and biological evaluation of bulk-fill composite resin.

The aim of this study was to evaluate the cytotoxic effect, degree of conversion (% DC), Vickers hardness (VH), and surface morphology of composite resins. Eleven resins, nine bulk-fill resins, and two conventional resins were evaluated. Each material was sampled to evaluate DC (using FTIR), VH, cytotoxicity (using MTT and Neutral Red - NR test), surface morphology (using SEM and AFM), and organic filler (using EDS).

Role of Surfactants in the Properties of Poly(Ethylene Terephthalate)/Purified Clay Nanocomposites.

Purified clay was modified with different amounts of alkyl ammonium and phosphonium salts and used as filler in the preparation of PET nanocomposites via melt intercalation. The effect of this type of filler on morphology and thermal and mechanical properties of PET nanocomposites was investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC), thermogravimetric analyses (TG), tensile properties, and transmission electron microscopy (TEM). The results showed that the mixture of alkyl ammonium and phosphonium salts favored the production of PET nanocomposites with intercalated and partially exfoliated morphologies with slight improvement in thermal stability.