International Journal of Biomaterials最新文献

Objective: In recent years, dental composite resins such as tooth-colored restoration are frequently used to restore dental cavities, coronal fractures, and congenital defects. This study aimed to evaluate the microleakage of two methacrylate-based composites (GC Kalore and Luna SDI) in class II restorations.

Materials and methods: In this experimental study, a total of 18 intact human premolars previously extracted for periodontal and orthodontic reasons were randomly divided into two groups. Similar class II cavities (box only) were prepared on all teeth and restored with two different composites. In group 1, a bonding agent (Single Bond 2-SB2; 3M ESPE) and Luna SDI composite in mesial cavities and GC Kalore composite in distal cavities were used. In group 2, Single Bond 2 and GC Kalore composite in mesial cavities and Luna SDI composite in distal cavities were applied. They were then subjected to 2000 thermal cycles in a water bath between 5-55°C (dwell time: 30 seconds in every bath and transfer time: 10 seconds). Then, they were immersed in a 2% basic fuchsin dye solution for 24 hours. After rinsing with water, they were sectioned mesiodistally and evaluated for microleakage using a stereomicroscope.

Results: Independent t-test (Mann-Whitney test) showed no statistically significant difference for microleakage in mesial and distal class II restorations between GC Kalore composite and Luna SDI composite (p = 1.000) (p= 0.852). A total of 83.4% of the Luna SDI composite samples and 66.6% of the GC Kalore composite had a microleakage score of ≤3 in class II cavities.

Conclusion: In the present study, marginal microleakage was found mainly at the gingival floor extending to 1/3 of the axial wall for the Luna SDI composite and GC Kalore composite. Furthermore, no statistically significant difference was found between the microleakage of the Class II cavities restored with Luna SDI composite and GC Kalore composite.

The COVID-19 pandemic has once again prompted people to resort to the remedies of folk and alternative medicine. Medicinal plants, because of their chemical composition, pharmacological properties, and the action of biologically active substances, can stop and relieve the symptoms of the disease. The purpose of the work is a comparative flora analysis of medicinal plants to identify the most prospective plant and further production of a remedy for the avoidance, treatment, and rehabilitation of COVID-19. The search for prospective medicinal plants was performed by analyzing the literature in online databases: Web of Science, Scopus, Google Scholar, and PubMed, including official WHO media sites. According to recent studies related to COVID-19, a significant number of medicinal plants with anti-inflammatory, antiviral, and immunostimulatory effects have been identified. A comparative study of nine medicinal plants was conducted to determine the most suitable medicinal plant to treat coronavirus infection. According to the results of the comparative analysis, Chamaenerion angustifolium Seg. showed itself as the most prospective medicinal plant with the greatest pharmacological effect compared with other types of medicinal plants. Its therapeutic properties allow physiological relief of 18 symptoms of coronavirus infection. It is advisable to conduct further clinical trials for the treatment and rehabilitation of COVID-19 using preparations from this plant.

Introduction: Without appropriate treatment, nerve injuries may result in permanent loss of function. Platelet-rich plasma (PRP) injection is found to help in nerve regeneration. PRP is a concentrated platelet derived from autologous blood with the potential to release various growth factors (GF) to promote nerve regeneration. This study aims to know the best time for PRP injection to promote nerve regeneration.

Methods: This is an experimental in vivo research using male New Zealand white rabbits in the randomized control group posttest only design. Samples were divided into 5 groups (1 control group and 4 treatment groups). The control group without PRP injection and treated groups injected immediately after nerve injury, 3 days, 7 days, and 14 days afterward. Nerve regeneration was evaluated by the histology specimen sacrificed on day 21. Inflammation cells and endoneurium vacuoles were counted as mean percentage of five nerve fragments in each injured nerve sample specimen.

Result: Inflammation cells and vacuole cells increased significantly when PRP was administered 3 days after injury (group 2) (respectively, 14 ± 6.7 and 56.6 ± 11.6) compared to all treatment groups (p < 0.005) (control group, respectively, 6 ± 2.6 and 15.7 ± 9.5). On the other hand, significantly lower endoneurium vacuoles and inflammation cells were found on "the day 14" sample group (respectively, 5 ± 1.3 and 5.2 ± 1.6) compared to all other groups (p < 0.005).

Conclusion: This study found that the best time for injecting PRP for nerve regeneration is 14 days after injury.

The influence of the surface finishing of breast implants on physicochemical and mechanical properties, before and after extreme degradation experiments, was investigated in this study. Removal of superficial layers after degradation was verified for both smooth and rough membranes, in which local erosion was verified. FTIR results demonstrated the generation of low-molecular-weight structures in all samples due to exposure to acidic and basic environments. Furthermore, smooth samples presented higher degrees of crosslinking than rough samples. Considering the mechanical properties, no difference was verified between smooth and rough samples as received and after degradation studies. However, the pH of the degradation solution had an influence on mechanical properties of the material and a basic environment caused greater deterioration of the mechanical properties compared to acidic conditions.

Magnetic Fe₃O₄ nanoparticles were synthesized from maize leaves and plantain peels extract mediators. Particles were characterized, and the inhibitory effects were studied on HeLa cells in vitro using cyclic voltammetry (CV). Voltammograms from the CV show that Fe₃O₄ NPs interaction with HeLa cells affected their electrochemical behavior. The nanoparticles formed with higher Fe³⁺/Fe²⁺ molar ratio (2.8 : 1) resulted in smaller crystallite sizes compared to those formed with lower Fe³⁺/Fe²⁺ molar ratio (1.4 : 1). The particles with the smallest crystallite size showed higher anodic peak currents, whereas the larger crystallite sizes resulted in lower anodic peak currents. The peak currents relate to cell inhibition and are confirmed by the half-maximum inhibitory concentration (IC₅₀). The findings show that the particles have a different inhibitory mechanism on HeLa cells ion transfer and are promising to be further exploited for cancer treatment.

In recent years, the green synthesis of nanoparticles via biological processes has attracted considerable attention. Herein, we introduce a facile and green approach for the synthesis of poriferous silver nanoparticles (Ag-NPs) decorated hydroxylapatite (HAp@Ag) nanoparticles with excellent antibacterial properties. All the nanocomposites were fully characterized in the solid state via various techniques such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and energy-dispersive X-ray spectrometer (EDX), in which the synthesized Ag-NPs (24 nm in diameter) and their homogeneous incorporation on HAp have been studied by ultraviolet-visible (UV-vis) technique, transmission electron microscopy (TEM), and dynamic light scattering (DLS) analysis. The obtained results indicate that the structure and morphology of HAp have no significant changes after the incorporation of Ag-NPs on its surface. Moreover, an impressive antibacterial activity of HAp@Ag nanocomposite against Gram-positive bacterium Staphylococcus aureus and Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa has been recorded by using the agar well diffusion method. As a result, the HAp@Ag nanocomposite promises to be a great biomedical material with high antibacterial properties.

Functionalized glutathione on chitosan-genipin cross-linked beads (CS-GG) was synthesized and tested as an adsorbent for the removal of Fe(II) and Cu(II) from aqueous solution. The beads were characterized by several techniques, including Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), CNS elementary analysis, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The effect of several parameters such as the pH, the temperature, and the contact time was tested to optimize the condition for the adsorption reaction. The beads were incubated in aqueous solutions contaminated with different concentrations of Fe(II) and Cu(II) (under the range concentration from 10 to 400 mg·L^-1), and the adsorption capacity was evaluated by inductively coupled plasma optical emission spectrometry (ICP-OES). The adsorption equilibrium was reached after 120 min of incubation under optimal pH 5 for Fe(II) and after 180 min under optimal pH 6 for Cu(II). According to the Langmuir isotherm, the maximum adsorption capacities (q _max) for Fe(II) and Cu(II) were 208 mg·g^-1 and 217 mg·g^-1, respectively. Our results showed that the adsorption efficiency of both metals on CS-GG beads was correlated with the degree of temperature. In addition, the adsorption reaction was spontaneous and endothermic, indicated by the positive values of ΔG ⁰ and ΔH ⁰. Therefore, the present study demonstrated that the new synthesized CS-GG beads had a strong adsorption capacity for Fe(II) and Cu(II) and were efficient to remove these trace metals from aqueous solution.

A novel natural hydroxyapatite (HAp) bioceramic was extracted from the ostrich cortical bone by the thermal decomposition method. HAp was characterized by different analytical tools such as thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM). Removal of organic impurities from the bone powder was confirmed by TGA analysis. FTIR spectra of HAp confirmed the presence of the major functional groups such as phosphate (PO₄ ^3-), hydroxyl (OH^-), and carbonate (CO₃ ^2-) in the bioceramic. The XRD data revealed that the HAp was the crystalline phase obtained by calcination of the bone powder at 950°C, and the SEM analyses confirmed the typical plate-like texture of the nanosized HAp crystals.

Tinospora cordifolia extract contains antioxidants such as polyphenols, and thus, it has been used as a natural phytochemical antioxidant therapeutic agent. Many of these compounds are insoluble or only partially soluble in water. In this study, we produced a novel aqueous nanoparticle formulation, with an average particle size of 182.9 ± 3.8 nm, to improve the dispersion of the bioactive compounds in water and to increment its bioavailability. The nanoparticles are composed of polyphenols, alkaloids, and glycosides. We studied the effect of this nanoparticle formulation on mouse 3T3 fibroblast cell viability and New Zealand rabbit dermal irritability tests. Concentrations of 2.5, 25, and 250 µg/mL resulted in similar cell viability to cells in culture media. An intermediate concentration of 12.45 mg/ml was used for the acute dermal irritability test. There were no severe alterations that compromised animal health. These results represent a precedent for application of such nanoparticles derived from plant stems, such as Tinospora cordifolia, in biomedicine and in antiaging cosmetic treatments.