Fabrication of Scaffolds for Bone-Tissue Regeneration

The present article describes the state of the art in the rapidly developing field of bone tissue engineering, where many disciplines, such as material science, mechanical engineering, clinical medicine and genetics, are interconnected. The main objective is to restore and improve the function of bone tissue by scaffolds, providing a suitable environment for tissue regeneration and repair. Strategies and materials used in oral regenerative therapies correspond to techniques generally used in bone tissue engineering. Researchers are focusing on developing and improving new materials to imitate the native biological neighborhood as authentically as possible. The most promising is a combination of cells and matrices (scaffolds) that can be fabricated from different kinds of materials. This review summarizes currently available materials and manufacturing technologies of scaffolds for bone-tissue regeneration

Molecular modelling of fullerene C60 functionalized by nitric oxide for use in biological environment

Abstract The unique potential of fullerene C60 for various biological applications has ignited significant interest. However, its inherent non-polarity poses a critical challenge for its effective integration within biological systems. This study delves into the intricate physicochemical characteristics of the innovative [C60 + NO] complex using density functional theory and time-dependent density functional theory. The computational analyses encompass molecular charge, surface electrostatic potential, and dipole moment evaluations. Impressively, the dipole moment of the [C60 + NO] complex significantly increases to 12.92 D. Meticulous surface analysis reveals a subtle interplay between molecular structures, indicating weak interactions. The analysis of the absorption spectrum unveils a noteworthy red-shift of 200 nm subsequent to complex formation. To elucidate the electron transfer mechanisms, we explore photo-induced electron transfer through CAM-B3LYP. This exploration elucidates intricate pathways governing electron transfer, with complementary insights gleaned from Marcus theory's outputs, especially the Gibbs free energy of electron transfer. Changes in the physicochemical properties of approaching C60 and NO molecules reveal interesting results compared to separate molecules. These findings resonate profoundly in the context of potential biological and pharmaceutical utilization. With implications for the biomedical area, the outcomes linked to the [C60 + NO] complex kindle optimism for pioneering biomedical applications

Biological Evaluation of Polyvinyl Alcohol Hydrogels Enriched by Hyaluronic Acid and Hydroxyapatite

This study aimed to develop polyvinyl alcohol (PVA) -based scaffold enriched with hyaluronic acid (HA) and hydroxyapatite (HAp) using physical crosslinking by freezing–thawing method. We accomplished biological evaluation of scaffolds, swelling degree, bioactivity assessment, and hemolytic test. The results showed that all types of scaffolds should be safe for use in the human body. The culturing of human osteoblast-like cells MG-63 and their proliferation showed better adhesion of cells due to the presence of HA and confirmed better proliferation depending on the amount of HAp. This paper gives the optimal composition of the scaffold and the optimal amount of the particular components of the scaffold. Based on our results we concluded that the best PVA/HA/HAp combination is in the ratio 3:1:2

Piezoelektricke senzory a jejich vyuziti pro mereni adsorpce plynu

Presented thesis deals with the design, construction and testing of the device for measuring of adsorption properties of gases and vapours at the polymer layer. A piezoelectric sensor represents the main part of the system. It is a quartz resonator coated with the layer of adsorption material. Opening chapter deals with historical backgrounds and reasons of development of the measurements technique as a line. It describes the evolution from the first simple sensors through the period of fast developing semi-conductor technology till today. Second chapter deals with a theoretical description of adsorption on solid substances. Third chapter describes the common properties of sensors. Classification, definitions and standards are described. Subject of fourth chapter is the piezoelectric sensor itsself. Fifth chapter deals with processing of the frequency signal. The last sixth chapter deals with testing of the device. It describes the results of measuring of properties of the whole system with the piezoelectric sensorAvailable from STL Prague, CZ / NTK - National Technical LibrarySIGLECZCzech Republi

In Situ Hydroxyapatite Synthesis Enhances Biocompatibility of PVA/HA Hydrogels

Bone tissue engineering tries to simulate natural behavior of hard tissues. This study aimed to produce scaffolds based on polyvinyl alcohol (PVA) and hyaluronic acid (HA) with hydroxyapatite (HAp) incorporated in two different ways, by in situ synthesis and physical mixing of pre-prepared HAp. In situ synthesis resulted in calcium deficient form of HAp with lower crystallinity. The proliferation of human osteoblast-like cells MG-63 proved to be better in the scaffolds with in situ synthesized HAp compared to those with physically mixed pre-prepared HAp. For scaffolds with PVA/HA/HAp ratio 3:1:2, there was significantly higher initial adhesion (p = 0.0440), as well as the proliferation in the following days (p < 0.001). It seemed to be advantageous improve the properties of the scaffold by in situ synthesizing of HAp directly in the organic matrix

Effect of Folic Acid, Betaine, Vitamin B6, and Vitamin B12 on Homocysteine and Dimethylglycine Levels in Middle-Aged Men Drinking White Wine

Moderate regular consumption of alcoholic beverages is believed to protect against atherosclerosis but can also increase homocysteine or dimethylglycine, which are putative risk factors for atherosclerosis. We aimed (1) to investigate the effect of alcohol consumption on vitamins and several metabolites involved in one-carbon metabolism; and (2) to find the most effective way of decreasing homocysteine during moderate alcohol consumption. Methods: Male volunteers (n = 117) were randomly divided into five groups: the wine-only group (control, 375 mL of white wine daily for one month) and four groups combining wine consumption with one of the supplemented substances (folic acid, betaine, and vitamins B12 or B6). Significant lowering of homocysteine concentration after the drinking period was found in subjects with concurrent folate and betaine supplementation. Vitamin B12 and vitamin B6 supplementation did not lead to a statistically significant change in homocysteine. According to a multiple linear regression model, the homocysteine change in the wine-only group was mainly determined by the interaction between the higher baseline homocysteine concentration and the change in dimethylglycine levels. Folate and betaine can attenuate possible adverse effects of moderate alcohol consumption. Dimethylglycine should be interpreted together with data on alcohol consumption and homocysteine concentration

Repeated Exposure of Nanostructured Titanium to Osteoblasts with Respect to Peri-Implantitis

Titanium offers excellent biocompatibility and extraordinary mechanical properties. As a result, it is used as a material for dental implants. Implants infected by peri-implantitis can be cleaned for successful re-osseointegration. Optimal surface properties, such as roughness and wettability, have a significant impact on cell adhesion. The aim of this study was to evaluate the adhesion and proliferation of osteoblasts on the surface of repeatedly cleaned nanostructured titanium samples. Human osteoblast-like cells MG-63 were seeded on nanostructured titanium specimens manufactured from rods produced by the equal channel angular pressing. For surface characterization, roughness and wettability were measured. Cell adhesion after 2 h as well as cell proliferation after 48 h from plating was assessed. We have found that this repeated cleaning of titanium surface reduced cell adhesion as well as proliferation. These events depend on interplay of surface properties, such as wettability, roughness and topography. It is difficult to distinguish which factors are responsible for these events and further investigations will be required. However, even after the several rounds of repeated cleaning, there was a certain rate of adhesion and proliferation recorded. Therefore the attempts to save failing implants by using in situ cleaning are promising

Proliferation of Osteoblasts on Laser-Modified Nanostructured Titanium Surfaces

Nanostructured titanium has become a useful material for biomedical applications such as dental implants. Certain surface properties (grain size, roughness, wettability) are highly expected to promote cell adhesion and osseointegration. The aim of this study was to compare the biocompatibilities of several titanium materials using human osteoblast cell line hFOB 1.19. Eight different types of specimens were examined: machined commercially pure grade 2 (cpTi2) and 4 (cpTi4) titanium, nanostructured titanium of the same grades (nTi2, nTi4), and corresponding specimens with laser-treated surfaces (cpTi2L, cpTi4L, nTi2L, nTi4L). Their surface topography was evaluated by means of scanning electron microscopy. Surface roughness was measured using a mechanical contact profilometer. Specimens with laser-treated surfaces had significantly higher surface roughness. Wettability was measured by the drop contact angle method. Nanostructured samples had significantly higher wettability. Cell proliferation after 48 hours from plating was assessed by viability and proliferation assay. The highest proliferation of osteoblasts was found in nTi4 specimens. The analysis of cell proliferation revealed a difference between machined and laser-treated specimens. The mean proliferation was lower on the laser-treated titanium materials. Although plain laser treatment increases surface roughness and wettability, it does not seem to lead to improved biocompatibility