Emoke Pall

Small versus Large Iron Oxide Magnetic Nanoparticles: Hyperthermia and Cell Uptake Properties.

Efficient use of magnetic hyperthermia in clinical cancer treatment requires biocompatible magnetic nanoparticles (MNPs), with improved heating capabilities. Small (~34 nm) and large (~270 nm) Fe3O4-MNPs were synthesized by means of a polyol method in polyethylene-glycol (PEG) and ethylene-glycol (EG), respectively. They were systematically investigated by means of X-ray diffraction, transmission electron microscopy and vibration sample magnetometry. Hyperthermia measurements showed that Specific Absorption Rate (SAR) dependence on the external alternating magnetic field amplitude (up to 65 kA/m, 355 kHz) presented a sigmoidal shape, with remarkable SAR saturation values of ~1400 W/gMNP for the small monocrystalline MNPs and only 400 W/gMNP for the large polycrystalline MNPs, in water. SAR values were slightly reduced in cell culture media, but decreased one order of magnitude in highly viscous PEG1000. Toxicity assays performed on four cell lines revealed almost no toxicity for the small MNPs and a very small level of toxicity for the large MNPs, up to a concentration of 0.2 mg/mL. Cellular uptake experiments revealed that both MNPs penetrated the cells through endocytosis, in a time dependent manner and escaped the endosomes with a faster kinetics for large MNPs. Biodegradation of large MNPs inside cells involved an all-or-nothing mechanism.

Comparative Assessment of Oral Mesenchymal Stem Cells Isolated from Healthy and Diseased Tissues

The aim of the present study was to isolate human mesenchymal stem cells (MSCs) from palatal connective and periodontal granulation tissues and to comparatively evaluate their properties. MSCs were isolated using the explant culture method. Adherence to plastic, specific antigen makeup, multipotent differentiation potential, functionality, and ultrastructural characteristics were investigated. The frequency of colony-forming unit fibroblasts for palatal-derived mesenchymal stem cells (pMSCs) was significantly higher than that of granulation tissue-derived mesenchymal stem cells (gtMSCs). A significantly higher population doubling time and lower migration potential were recorded for gtMSCs than for pMSCs. Both cell lines were positive for CD105, CD73, CD90, CD44, and CD49f, and negative for CD34, CD45, and HLA-DR, but the level of expression was different. MSCs from both sources were relatively uniform in their ultrastructure. Generally, both cell lines possessed a large, irregular-shaped euchromatic nucleus, and cytoplasm rich in mitochondria, lysosomes, and endoplasmic reticulum. The periphery of the plasma membrane displayed many small filopodia. MSCs from both cell lines were successfully differentiated into osteogenic, adiopogenic, and chondrogenic lineages. Both healthy and diseased tissues may be considered as valuable sources of MSCs for regenerative medicine owing to the high acceptance and fewer complications during harvesting.

Synthesis, crystal structure and characterization of new biologically active Cu(II) complexes with ligand derived from N-substituted sulfonamide

AbstractA new N-sulfonamide ligand (HL1 = N-(5-(4-methoxyphenyl)-[1,3,4]–thiadiazole–2-yl)-toluenesulfonamide) and two Cu(II) complexes, [Cu(L1)2(py)2] (C1) and [Cu(L2)2(py)2(H2O)] (C2) (HL2 = N-(5-(4-methylphenyl)-[1,3,4]–thiadiazole–2-yl)-benzenesulfonamide) were synthesized. The X-ray crystal structures of the complexes were determined. In the complex C1, the Cu(II) ion is four-coordinated, forming a CuN4 chromophore and in the complex C2, the Cu(II) ion is five-coordinated, forming a CuN4O chromophore. The ligand acts as monodentate, coordinating the Cu(II) ion through a single Nthiadiazole atom. The molecules from the reaction medium (pyridine and water) are also involved in the coordination of the Cu(II) ion. The complexes C1 and C2 are square-planar and a slightly distorted square pyramidal, respectively. The compounds were characterized by FT-IR, electronic, EPR spectroscopic and magnetic methods. The nuclease binding activity studies of the synthesized complexes confirm their capacity to cleave the DNA molecule. The cytotoxicity studies were carried out on melanoma cell line WM35 which confirm that both compounds inhibit the growth of these cells. They have a higher activity compared to a platinum drug, carboplatin. Graphical AbstractA new N-sulfonamide ligand (HL1= N-(5-(4-methoxyphenyl)-[1,3,4]–thiadiazole–2-yl)-toluenesulfonamide) and two Cu(II) complexes, [Cu(L1)2(py)2] and[Cu(L2)2(py)2(H2O)] (HL2= N-(5-(4-methylphenyl)-[1,3,4]–thiadiazole–2-yl)-benzenesulfonamide) were synthesized.The X-ray crystal structures of the complexes have been determined. Interaction of complexes with the DNA molecule and cytotoxicity studies were carried out.

New insights into the cellular makeup and progenitor potential of palatal connective tissues

The present study investigated the regenerative potential of connective tissues harvested from two palatal areas widely used as donor sites for muco‐gingival surgical approaches. Connective tissue grafts (CTGs) were obtained by de‐epithelialisation of a free gingival graft (deCTG) and by a split flap approach from a previous donor site (reCTG). Two types of mesenchymal stem cell (MSCs) were isolated and were named de‐epithelialised MSCs (deMSCs) and re‐entry MSCs (reMSCs). The cells were characterised and cellular functionality was investigated. CTGs were evaluated using immunohistochemical and ultrastructural approaches. No significant differences were observed regarding the frequency of colony‐forming unit‐ fibroblasts, migration potential, and population doubling time between the two cell lines (p > 0.05). Both cell lines showed positivity for CD105, CD73, CD90, and CD44 and negative expression for CD34/45, CD14, CD79a, and HLA‐DR. MSCs from both cell lines successfully differentiated into osteogenic, adipogenic, and chondrogenic lineages. Cells expressing antigens characteristic of CD34+ stromal cells (CD34+, αSMA−, CD31−) were traced in both CTGs. Ultrastructural analysis highlighted the presence of putative progenitors, namely fibroblasts,—in the pericapillary regions and in remote regions of the lamina propria‐ and pericytes—surrounding the capillaries. This study provides supplementary arguments for the use of CTG grafts in clinical practice due to the presence of putative progenitor cell. However, results were inconclusive regarding clinical decision‐making to determine optimal harvesting area. Prior harvesting in the donor area did not appear to alter the regenerative capabilities of the connective tissue.

Equine Embryo Sexing and Ultrasonographic Foetal Sexing - Interests and Applicability.

The ability to choose the sex of the offspring is of upmost economic importance for horse breeders. Unlike other species, horses present several reproductive peculiarities that interfere with assisted reproductive technologies used in other large animals (such as bovine) and make them difficult to apply. Thus, there is a great interest to determine the sex of the offspring as soon as possible. This has led to the development of several technologies to serve this purpose, which can be classified into two categories. One is equine embryo sexing by either non‐invasive biotechnological methods, such as monitoring of X‐linked enzymes before X chromosome inactivation and detection of sex‐specific antigen, or by invasive biotechnological methods, such as cytogenetic analysis and polymerase chain reaction (PCR). The other one is equine foetus sexing using ultrasound scanning in different stages of its development (early, mid or late), by different approaches (transrectally or transabdominally). This can be performed with classic B‐mode ultrasound machines or using 3D‐mode and Doppler‐mode scanners. This review article offers a comprehensive overview of the current status of these procedures as well as an assessment of their interests and applicability.

Canine Amniotic Membrane Derived Mesenchymal Stem Cells- Potential Sources for Regenerative Medicine

Abstract Canine mesenchymal stem cells (MSCs) can be defined with self renew potential and specific differentiation capacity. Amiotic membrane represent an important source of MSCs, which can be harvested by minimally invasive methods. The aim of our study was to evaluate the growth characteristics of canine amniotic membrane derived mesenchymal stem cells. The placenta samples were collected after cesarean section from healthy mixed breed dogs. MSCs isolation was performed using enzymatic method. Isolated cells were cultured in propagation medium: Dulbecco’s Modified Eagle’s Medium/F12 (DMEM/F12, Gibco) supplemented with 10% fetal bovine serum (FBS, Gibco) and 1% antibiotic-antimycotic (Sigma-Aldrich). The medium was changed after 4 days. The cell doubling number, cell proliferation capacity, cell doubling time, daily duplication rate and clonogenic efficacy were evaluated. Our study demonstrate the self renew potential of canine amniotic membrane derived mesenchymal stem cells, and can represent a potential source of stem cells for canine regenerative medicine.

Carcass Characteristics of Purebred Tsurcana Lambs and F1 Crossbreds (Tsurcana X Vendeen)

The data presented in this article is included in a larger research regarding the improvement of the Romanian lamb towards the meat production. The study has been carried out from 2015 to 2016. The lambs included in this study were obtained following a protocol of estrus synchronization in Tsurcana ewes and the grouped lambing. The research is a pilot study conducted on a representative sample for the selected groups of animals and further research is needed to complete the research. The research aims to compare carcass characteristics of purebred Tsurcana lambs and Tsurcana crossed with Vendeen lambs. The criteria assessed were: the chemical composition of purebred and crossbred meat, the live body weight, the slaughtering performance and the weight of different carcass cuts. For almost all criteria chosen the crossbred individuals recorded better results.

Advanced Techniques of Bovine Semen Analysis

The aim of the study was to assess bull semen fertility parameters using the classical techniques of sperm quality evaluation (density, motility, viability, and morphology, evaluated by light microscopy, in addition to concentration, evaluated via the hemocytometer and microspermatocrit), as well as advanced techniques, like computer assisted sperm analysis (CASA) and flow cytometry. Results obtained for classical techniques were comparable to those obtained by automated methods, without significant differences between parameters. The classical methods were inexpensive but required more time and attention, while the operator’s experience was a key element for accurate assessment of sperm parameters. The advanced techniques were fast and objective, but required expensive equipment and dedicated personnel, with proper training in the field. Therefore, classical techniques are suitable for clinics where occasional evaluation of bulls’ fertility parameters is performed, while the advanced methods should be implemented in semen companies, as well as in fertility clinics and research laboratories.

Applications of inflammation-derived gingival stem cells for testing the biocompatibility of dental restorative biomaterials

BACKGROUND Normal or inflamed gingival tissues are regarded as a source of mesenchymal stem cells (MSCs) abundant and easily accessible through minimally invasive dental procedures. Due to the proximity of dental resin composites to gingival tissues and to the possible local cytotoxic effect of the eluted components, gingiva-derived MSCs could be used to investigate the biocompatibility of dental biomaterials. PURPOSE The present research aimed to isolate (MSCs) from inflamed and normal gingiva, to fully characterize them and to observe their behavior in relation with some commercial resin composite materials and one experimental material. MATERIAL AND METHODS Following their isolation, putative MSCs from both gingival sources were grown under the same culture conditions and characterized by immunophenotyping of cell surface antigens by flow-cytometry and transcription factors by immunocytochemical staining. Moreover, stemness gene expression was evaluated by RT-PCR analysis. Multipotent mesenchymal differentiation potential was investigated. Osteogenic and neurogenic differentiated cells were highlighted by immunocytochemical staining, chondrogenic cells by cytochemical staining, and adipocytes by cytochemical staining and spectrophotometry, respectively. Resin composite cytotoxicity was evaluated by cell membrane fluorescent labeling with PKH 26 and MTT assay. The results of PKH labeling were statistically analysed using two-way RM ANOVA with Bonferroni post-tests. For MTT assay, two-way RM ANOVA with Bonferroni post-tests and unpaired t test with Welchs correction were used. RESULTS A similar expression pattern of surface markers was observed. The cells were positive for CD105, CD73, CD90, CD49e, CD29, CD44 and CD166 and negative for CD45, CD34, CD14, CD79, HLA-DR and CD117 indicating a mesenchymal stem cell phenotype. The qRT-PCR analysis revealed a low gene expression for NOG, BMP4 and Oct3/4 and an increased expression for Nanog in both cells lines. Immunocytochemical analysis highlighted a more intense protein expression for Nanog, Oct3/4 and Sox-2 in MSCs derived from normal gingiva than from inflamed gingiva. Multipotent differentiation capacity of MSCs isolated from both sources was highlighted. The tested materials had no hazardous effect on MSCs as the two cell lines developed well onto resin composite substrates. Cell counting revealed some significant differences in the number of PKH-labeled MSCs at some experimental moments. Also, some differences in cell viability were recorded indicating better developmental conditions offered by some of the tested biomaterials. CONCLUSIONS The experimental resin composite behaved like the most biocompatible commercial material. Inflamed gingiva-derived MSCs retain their stem cell properties and could be used as a valuable cell line for testing dental biomaterials.

Cytotoxicity of Experimental Resin Composites on Mesenchymal Stem Cells Isolated from Two Oral Sources.

Resin composite materials that are used to restore tooth cervical lesions associated with gingival recessions can hamper healing after root coverage surgeries. This study evaluates the in vitro cytotoxic effect of five resin composites (two commercial and three experimental) on oral mesenchymal stem cells (MSCs) and the persistence of stemness properties in high passage MSCs. Sorption and solubility tests were made for all materials. MSCs were isolated from re-entry palatal and periodontal granulation tissues and were characterized and cultured on composite discs. Cytotoxicity of the materials was evaluated by the Alamar Blue viability test, by Paul Karl Horan (PKH) labeling, and by immunocytochemical staining for actin. Water and saliva sorption and solubility data revealed that two of the experimental materials behaved comparable with the marketed resin composites. The Alamar Blue viability test shows that both cell lines grew well on composite discs that seemed to induce no apparent toxic effects. No signs of disruption of cytoskeleton organization was seen. Experimental resin composites can be recommended for further investigation for obtaining approval for use. The standard minimal criteria were fulfilled for high passage MSCs. Palatal tissue regains its regenerative properties in terms of MSC presence in the re-entry area after 6 months of healing.