Papers by Keyword: In Vitro

Abstract: Osteogenesis and degradability of bioresorbable biphasic gypsum-carbonated apatite granules (BPG) were investigated. Three different sizes of gypsum, 300-600 μm (small), 600-1000 μm (medium) and 1000-2000 μm (large), denoted as S, M and L respectively, were developed through the crushing and sieving method. Exposure of gypsum granules in carbonate and phosphate sources formed BPG through dissolution and precipitation mechanism. BPG was firstly examined by X-ray Diffractometer (XRD) and Fourier Transform Infrared Spectrometer (FTIR) to confirm its phase and chemical composition respectively. In-vitro cell proliferation, alkaline phosphatase (ALP) activity and adhesion of human osteoblast (hFOB) were investigated for osteogenesis evaluation. Degradability in phosphate buffer saline (PBS) was characterized by weight loss whereas apatite mineralization on the BPG surface was examined using Scanning Electron Microscope (SEM). BPG with 300-600 μm and 600-1000 μm enhanced osteogenic differentiation of hFOB and accelerated differentiation process better than 1000-2000 μm as indicated by cell proliferation and ALP activity. Good hFOB adhesion was observed on all BPG surfaces. The weight loss of L and M was 68% and 59%, respectively, which are higher than S at only 32%, indicating faster degradation of large BPG compared to smaller granules upon immersion for 35 days. This in turn, suggested the ionic dissolution of BPG which has contributed to the apatite formation on its surface. The results suggest, the BPG mimicked the bone matrix, exhibited good osteogenesis and degradability, which might be used as a potential candidate for bone tissue engineering.

Abstract: The present work focuses on the development of biodegradable PLGA nanoparticles (NPs) for controlled release of a breast cancer drug, letrozole. NPs of different drug-polymer ratio formulations (F1, F2, F3, F4) were fabricated using solvent evaporation technique. Physico-chemical characteristics of these NPs were assessed using dynamic light scattering (DLS) spectrophotometer. In-vitro drug release study was carried out over an extended period of 30 days at 37 °C in simulated physiological fluid. To evaluate the release kinetics, data was fitted to different models. NPs with various sizes and size distributions were obtained by altering the drug-polymer ratio. Zeta potential of PLGA and drug loaded NPs were found to be-29.4± 1.3 mV and-21.0±0.6 mV, respectively. The release kinetics of the drug from NPs was in good agreement with Korsmeyer-Peppas model, ensuring controlled release of the drug from the NPs. In-vitro release studies showed high correlation coefficient (R² = 0.90) for formulation F2 and F3 up to 30 days. It is concluded that NPs with F2 and F3 formulations provide a controlled release of the incorporated drug and, therefore, hold promise to be investigated further in detail.

Abstract: The global need of biomaterial products especially in bone clinical application increases every year. The gold methods like autograft and allograft have some limitations in the application such as the availability of donor sites, antigenicity issues, the high cost, etc. To solve the problems, many researches and activities in the field of biomaterial have been conducted continuously in the past decades to develop the proper synthetic materials for bone substitutes which have properties similar to bone tissue. In this research, the synthesis of biocomposite for bone scaffold application prepared by freeze drying method has been done successfully. The materials used are biopolymer (alginate and chitosan) and bioceramics (carbonate apatite) with certain mixing variations. SEM result showed that the pores obtained by freeze drying method can mimic the pores of actual bone thus they will be able to resemble cells microenvironment, enhance interface interaction, and support cell proliferation. The existence of carbonate apatite on the scaffold’s surface can be observed with particle size of 0.05 – 1 μm and has been dispersed evenly. These results are in good agreement with FT-IR analysis that indicates the presence of PO₄^3– functional group on the scaffold at wave numbers 569 and 1041.56 cm^–1 and CO₃^2– functional group at wave number 1411.89 cm^–1. The in vitro biological evaluation of HeLa cells which exposed to extract solution of scaffold (in some variations of concentration) indicated that the scaffold obtained was not cytotoxic to the HeLa cells.

Abstract: Research and development on the biomaterials are increasing due to the demand for materials that can bond to the living bones and by any chance can avoid second surgery procedure. Good bonding between bones and biomaterials or artificial implant can avoid loosening that due to the friction and wear. Currently, magnesium alloys are being actively researched because of their ability to serve as structural support in short term and can be absorbed in the body after healing process is completed. The addition of bioactive components such as hydroxyapatite and bioglass into magnesium is made to improve the bioactivity behavior of magnesium alloys. This paper summarizes the past and current studies of magnesium alloys in regards of in vitro bioactivity behavior, biomineralization and apatite formation mechanism.

Abstract: In this study, radical scavenging properties and anti-fatigue activities of Angelica sinensis polysaccharides (ASP) were evaluated in vitro and in vivo, respectively. Forced swimming test of mice were carried out after 30 days of ASP administration (60, 120, 240 mg/kg·d), and the blood glucose, blood lactate, hemoglobin, liver glycogen and muscle glycogen were determined. The in vitro study showed that ASP had antioxidant activities, which exhibited scavenging effects on 2,2-Diphenyl-1-picrylhydrazyl (DPPH), hydroxyl and superoxide anions radicals. The in vitro study showed that ASP had anti-fatigue activities, which could extend the exhaustive swimming time, increase levels of blood glucose, hemoglobin, liver glycogen and muscle glycogen activities, and decrease blood lactate levels of mice.

Abstract: The stages of getting the planting material for laying plantations of the triploid aspen (Populus tremula L.) are illustrated in this work. The source material selected from the genetic fund “The gigantic aspens” is characterized. The peculiarities of using the method of clonal micropropagation when getting the planting material, the usage of a rootstock as a source of donor explants for the introduction into the culture in vitro, the influence of a kind of nutrient media and growth regulators NAA and BAP on the growth and the development of microsprouts. The distinctions in the speed of the growth of the culture in vitro of diploid and triploid clones have been analyzed. The adaptation of the plants-regenerants to the soil-conditions.

Abstract: Magnesium (Mg) is an attractive biomaterial due to its desirable biodegradable and mechanical properties. In this study, we compared the degradation behavior of Mg and a new Mg alloy incubated in both whole blood and platelet rich plasma (PRP) for two hours under standard cell culture conditions. To avoid settling of red blood cells, tubes with whole blood were under constant rotation during the incubation. Post-incubation solutions were collected, centrifuged, and analyzed for pH and Mg ion concentration. Mg and Mg alloy samples were fixed with a 3% glutaraldehyde solution, dehydrated using an ethanol series, critical point dried, sputter coated, and imaged with a field emission scanning electron microscope. Analysis of the post-incubation solutions showed PRP had greater concentrations of Mg ions and higher pH values when compared with whole blood. This indicated that the Mg and Mg alloy degraded faster when incubated in PRP than in whole blood. When comparing the surface of the materials after incubation with whole blood and PRP, the surfaces of Mg and Mg alloy that was incubated in PRP had larger cracks and grain boundaries than the samples incubated in whole blood. Additionally, more particulate microstructures were observed on the samples incubated in PRP as opposed to whole blood. Further studies are still needed to elucidate the differences in degradation of Mg alloys in whole blood and PRP.

Abstract: In the present study, the in vitro bioactivity of silver-doped hydroxyapatite (HAp/Ag) scaffolds was investigated. HAp/Ag was prepared using two different modified wet precipitation methods. The X-ray powder diffraction (XRD) results showed, that sintered HAp/Ag samples prepared using method (I) contain two phases HAp and Ag, but samples prepared by method (II) contain three different phases - HAp, Ag and AgO. After 2 month incubation period in simulated body fluid (SBF), surface of HAp/Ag scaffolds was coated with bone-like apatite. Thickness of bone-like apatite layer increased from 2 μm up to 32 μm, increasing the incubation period.

Abstract: The solution blow spinning is presented as a method of obtaining tissue engineering scaffolds. The different forming modes were used and the optimum experimental conditions were found. It is shown that nonwoven polylactide scaffolds with required surface morphology can be obtained. These samples were studied in case of biodegradation in simulation body fluid. It was found that during scaffold dissolution the pH of the solution changes insignificantly (6.85) despite the exponential increase of the monomers of lactic acid. The calcium and phosphorus ion exchange between the scaffold and solution was observed in the surface and bulk of the material what makes possible to use scaffolds for regenerative medicine.

Abstract: The aim of this study is to induce bone from immature muscular tissue in vitro using recombinant human BMP (rhBMP)-2 and expanded polytetrafluoroethylene (ePTFE) as a scaffold. Commercially available rhBMP-2 was used in this experiment. IMTs were harvested from the forelimbs of 20th Sprague-Dawley embryonic rats and placed into a homogenizer with 10ng/μl of rhBMP-2 and then homogenized. The homogenized IMT was placed on ePTFE and cultured for 2 weeks. The analyses of histological observation, electron probe micro analyzer (EPMA), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were carried out following culture. The bone-like tissue, which was made up of osteoblast-like cells and osteoids, was partially observed by H-E staining. Moreover, strong mineral deposition was observed in the extracellular matrix by von Kossa staining. Ca, P and O were detected in the extracellular matrix by EPMA and were confirmed to be at almost the same position based on the findings of synchronized images. XRD patterns and FTIR spectra of specimen were found to have typical hydroxyapatite crystal peaks and spectra, respectively. These results suggest that rhBMP-2 induced IMT differentiation into bone-like tissue in vitro.