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A new bicomponent hybrid material was obtained by encapsulating quercetin in PLGA using solvent evaporation method. The morphological aspects of the samples were established by scanning electron microscopy (SEM). Particle size distribution was determined by dynamic light scattering (DLS), numerical distribution showing that the particles are micrometric, with two granulometric intervals: [385-479] nm and [662-918] nm. Morphology was typical for PLGA, spherical one; the obtained particles are porous with micrometric pores. Zeta potential (ZP, -4.84mV) showed that the particles have electronegative surface charge. The loading efficiency was determined spectrophotometric and it was 18.3% in the mentioned synthesis conditions.

This study aimed to compare the impact of thermal cycling on the flexural strength (σfs) of 3-dimensional (3D) printer resins and polymethyl methacrylate (PMMA). It also aimed to evaluate different surface treatment protocols and surface sealant applications on the surface roughness (Ra) and surface hardness (VHN) of the resins used. Rectangular (25×2×2 mm) and disc (Ø10×2-mm) specimens were fabricated from auto-polymerized PMMA, and 3D-printed resins were tested for mechanical properties (ISO 10477) using thermal cycling (n=10). Disc specimens were separated into three groups (n=10) based on the surface treatments: conventional sanding (C), disk polishing (P), and surface sealant coating (O). Ra and VHN values were statistically analyzed with the Kolmogorov Smirnov, Shapiro Wilk, Independent Samples t-test, Mann-Whitney test, one-way ANOVA test and Kruskal Wallis test (α =.05). A significant main effect was found on the flexural strength analysis for each of the two factors: thermal cycling procedure (p[0.001) and materials (p 0.001). A significant main effect was found on the surface roughness and hardness analysis for each of the two factors: surface treatment protocols (p[0.001) and materials (p[0.001). Based on the results; interim materials produced with 3D-printed resins have better mechanical properties than conventionally polymerized materials. Coated materials had lower surface roughness values than polished ones, and adding a surface sealant agent increased their hardness significantly.

The study investigates the effects of aggressive factors environments commonly found in industrial environments on the elastomeric material TPU 95 A, which is integrated into a multitude of soft robotics applications. Specimens made of TPU 95 A were subjected to aggressive liquid media - cooling oil, distilled water, and ultraviolet radiation (UV-C) to evaluate changes in their mechanical and elastic properties following uniaxial tensile tests. The research, carried out using additive manufacturing technology, highlights the importance of monitoring how the external factors impact elastic and mechanical characteristics of TPU 95 A material. The results obtained after the experimental tests proves to us that the aggressive media analyzed had a greater or lesser influence on the material. By uniaxial tensile tests, it was found that the liquid absorption had a very important impact on the tensile strength of the material. For example, at 1.02% absorption in distilled water, the maximum value of the ultimate strain decreased by 0.257 mm/mm, and at 3.06% absorption in cooling oil, the maximum value of the strain decreased by 0.672 mm/mm.

Using propylene-ethylene block copolymer (PPB) and metallocene polypropylene random (mPPR) as matrix, olefin block copolymer (OBC) and metallocene polyethylene (mPE) as reinforcement, trimethylolpropane trimethacrylate as sensitizer, antioxidant 1010 and dioctadecyl 3,3-Thio-dipropionate as antioxidant, the radiation-crosslinked polypropylene with excellent high-temperature performance was prepared by one-step process and it was used to produce the heat shrinkable tape with three layers structure further. The effect of the formula, the orientation, the crosslinking, the heat treatment and shrink on the crosslinked-polypropylene were studied. The results show that the crosslinked-polypropylene has optimum overall property when the amounts of PPB, mPPR, OBC, and mPE were 50, 10, 15, and 15 phr, respectively. After the orientation in one-step process and the radiation crosslinking with the irradiation dose of 6 Mrad, the tensile strength, the elongation at break, the shrinkage ration, the gel content of the crosslinked-polypropylene reached 33 MPa, 390%, 30%, 51%, respectively. After heat treatment, its mechanical properties further improved and the decrease of its tensile strength and elongation at break did not exceed 15% after thermal ageing at 130 oC for 100 days. Moreover, the corresponding heat shrinkable tapes show outstanding peel strength, impact strength and cathodic disbondment properties in various conditions.

Bone substitutes are found in natural or synthetic form. Different types of bone substitutes are used, including alloplasts or xenografts. These materials should be biocompatible, and have adequate mechanical properties. Bone substitute materials have become a clinical procedure in the treatment of periodontitis. In current practice, various bone substitutes are used, including alloplasts (β-tricalcium phosphate) and xenografts with good results. The aim of this study was to evaluate the efficacy of alloplasts (β-tricalcium phosphate) and xenografts in the preprosthodontic periodontal therapy of intrabony defects. The study was carried out on a group of patients with severe periodontitis treated by periodontal surgery, in which these materials were used as bone substitutes. Patients presented or not performed fixed prosthetic restorations. These biomaterials function as osteoconductive scaffolds. Both materials ensure the filling of bone defects in periodontal intrabony defects through their own capabilities. Alloplasts (β-tricalcium phosphate) and xenografts are effective in periodontal regeneration. The evaluation of periodontal parameters after the surgical interventions with bone substitutes indicates the favorable prognosis over time of the two types of materials used.

The study aims to present the results obtained following the burned patients micrografting, from the perspective of analyzing the physical and chemical properties of polyamide as a support for skin micrografts. To carry out the project, the data was obtained from the use of 100 micrografting kits with polyamide support which were analyzed and the results were interpreted in order to obtain relevant information regarding the effect of polyamide in accelerating the healing process, the rate of postoperative complications, as well as the acceleration in integration of the skin grafts.The comparative analysis was performed with a control group consisting of 108 free split skin grafts covered with classic cotton tulle. The conclusions of the study show that the use of polyamide in the therapeutic protocol of micrografting accelerates the process of grafts integration, while reducing the rate of postoperative complications, as well as decreasing the lenght of hospitalization.

The shell, as the main structure of 3D printed fused filament fabrication (FFF) models, plays a key role in the tensile strength of FFF models. In order to optimise the structural parameters of the shell and improve the tensile strength of FFF models, especially those printed with low-density infill. In this paper, polylactic acid (PLA) filament was selected as the printing material, and the influence of shell structural parameters (shell texture angle, shell layer height, and shell thickness) on the tensile strength of FFF models was investigated by one-way and orthogonal tests. The results of the one-way test show that the tensile strength of the FFF models increases as the shell texture angle decreases, the shell layer height decreases, and the shell thickness increases. Orthogonal test results show that the shell structure parameters affect the tensile strength of the FFF models in the following degree: shell thickness ] shell texture angle ] shell layer height. The optimised shell structure parameters are: shell texture angle of 0°, shell layer height of 0.1 mm, shell thickness of 2.0 mm, and the tensile strength of the FFF models is the largest with this optimised parameter, which is 19.68 MPa.

As the amount of agricultural waste produced annually worldwide is very high, numerous studies have been conducted with the aim of using them in the structure of composite materials that have a minimal impact on the environment, reduced costs, and can be used in various fields of activity. In this research, four types of composite materials were cast, with a reinforcement of chopped corn cobs and with a matrix of acrylic resin, respectively, of three hybrid resins having various mass proportions, where Dammar natural resin prevailed. The chemical structure of the composites with hybrid matrix was determined using molecular spectroscopic microanalysis, and some mechanical properties of all the composites were investigated. It was found that the values of the obtained mechanical characteristics were limited.

The paper presents the results of experimental research conducted in the laboratory with the aim of obtaining new composite materials used for automotive brake pads. The friction material consists of seven components; five of them were kept in a constant proportion (60%wt), and two (40%wt) were varied in fraction volume, namely phenolic resin and hemp fiber. For each recipe, the effect of phenolic resin on density, porosity, hardness, thermal stability, and friction-wear characteristics was analyzed. The study indicates that finding the optimal balance between phenolic resin and hemp fiber constitutes an efficient approach in improving friction performance. Additionally, the study demonstrates the viability of organic composite materials in braking applications, as they are capable of meeting the performance levels established by traditional materials.

The monoclonal antibody bevacizumab, which neutralizes vascular endothelial growth factor, significantly affects the migration, survival, and proliferation of cells - all of which are critical for the growth and spread of tumors. The current study`s objective was to create polyurethane structures that are more soluble in water so they may be employed as this active agent`s transmembrane carrier. A polymer drug delivery system was created using an aliphatic isocyanate and a combination of ether and ester polyols, resulting in a suitable release profile and membrane penetrability. The solubility, pH, and refractivity index measurements, the size distribution and surface charge, the encapsulation efficacy and release profile, the proliferation of cells, and skin irritation tests on mice were used to describe the two samples. Our findings reveal that nearly neutral acido-basic polymer structures were achieved, ranging in size from 187 to 423 nm. Zeta potential values suggest a minor alteration in the propensity to form clusters in the sample with increased solubility, and UV-Vis analyses demonstrate an approximately 63±2% encapsulation efficacy. In terms of the samples` biosafety profile, the tests conducted on mouse skin and cell cultures did not result in significant adverse effects at the concentrations that were examined. The results of this preclinical investigation indicate that adding polar groups to polyurethane macromolecular chains improves aqueous solubility without changing the polymer carrier`s other properties.