Cartilage repair using hydrogels: a critical review of in vivo experimental designs

Prova tipográfica This review analyzes the outcomes and technical aspects of in vivo studies published in the past decade using gels and hydrogels for cartilage repair. Using PubMed search engine, original research publications during the period of 2002/01/01 to 2015/04/30 identifi ed 115 published papers. Of these, 3 studies failed to fi nd a statistically significant improvement of treatment group as compared to control and 18 studies did not clearly identify hyaline-like cartilage formation in the treated groups. The most frequent repaired lesion was the rabbit acute full thickness trochlear defect, using a scaff old combining a gel or hydrogel and other material. One third of the scaff olds were cell-free (35%) and the majority of the studies did not use growth factors (71%). The present review may constitute a useful tool in design of future studies, as limitations of study designs are pointed and results in terms of translation to human application is discussed.ARTICULATE project 623 (QREN-13/SI/2011-23189

Amniotic fluid-derived stem cells for cardiovascular tissue engineering applications

Recent research has demonstrated that a population of stem cells can be isolated from amniotic fluid removed by amniocentesis that are broadly multipotent and non-tumorogenic. These amniotic fluid-derived stem cells (AFSC) could potentially provide an autologous cell source for treatment of congenital defects identified during gestation, particularly cardiovascular defects. In this review, the various methods of isolating, sorting and culturing AFSC are compared, along with techniques for inducing differentiation into cardiac myocytes and endothelial cells. Though research has not demonstrated complete and high yield cardiac differentiation, AFSC have been shown to effectively differentiate into endothelial cells and can effectively support cardiac tissue. Additionally, several tissue engineering and regenerative therapeutic approaches for the use of these cells in heart patches, injection after myocardial infarction, heart valves, vascularized scaffolds and blood vessels are summarized. These applications show great promise in the treatment of congenital cardiovascular defects, and further studies of isolation, culture, and differentiation of AFSC will help to develop their use for tissue engineering, regenerative medicine, and cardiovascular therapies

Soybean genotypic differences in sensitivity of symbiotic nitrogen fixation to soil dehydration

Soybean genotypic differences in sensitivity of symbiotic nitrogen fixation were monitored on the following varieties: Impala (South African Republic), Maverick (USA), Rankoshi No.1h (Japan) and their reactions to the water supply at the beginning of the growth stage R1 and R2 – blooming in an interaction with the Nitrazon inoculation of the seeds before a sowing. Seeding of the particular soybean genotypes was made into the containers whilst 50% of seed corn from each genotype was before the sowing inoculated by the usage of Nitrazon inoculant. Water stress was secured by an irrigation interruption for a 7-day period in the mentioned growth stage. This stress had a negative impact on the relative water content (%RWC) plants, proline content (μmol.g-1Fresh Weight), osmotic potential (MPa), stress index as well as an amount of nodules on the roots by the all monitored varieties. According to an evaluation of the mentioned indicators more significant proline accumulation was confirmed by the genotype Maverick especially by the variant exposed to water deficit (3,25 μmol.g-1FW according to the calculations on 100% RWC) without the inoculant Nitrazon use and inoculating variant 2,99 μmol.g-1Fresh Weight according to calculations on 100% RWC. Genotype Maverick had got the best reaction to water stress and even more noticeable resistance to the stress was monitored in the variant with Nitrazon application in the foregoing seed treatment of soybean seeds. The opposite response to the inoculation was monitored by Impala genotype

Comparison of follicular fluid and serum levels of Inhibin A and Inhibin B with calculated indices used as predictive markers of ovarian hyperstimulation syndrome in IVF patients

<p>Abstract</p> <p>Background</p> <p>Ovarian Hyperstimulation Syndrome (OHSS) is a severe health complication observed in some patients undergoing hormonal stimulation during IVF. Presence of OHSS is often associated with a high count of growing follicles responding to FSH hyperstimulation. However, the number of responding follicles may not be sufficient enough to predict the onset and severity of OHSS. The aim of this study was to find whether follicular fluid (FF) and serum concentrations of Inhibin A and Inhibin B in patients undergoing IVF treatment may serve as a predictor of OHSS status independent of the growing follicles count.</p> <p>Methods</p> <p>Serum and follicular fluid of fifty-three women undertaking the IVF program were separated into four groups according to their OHSS status and growing follicles count and analyzed for serum and FF concentrations of Inhibin A and Inhibin B. The resulting data were combined with clinical and demographic data to calculate indices independent of the growing follicles count.</p> <p>Results</p> <p>Serum Inhibin A and Inhibin B concentrations showed no significant difference between the severe OHSS group and the control group without OHSS. Moreover, the serum concentrations of Inhibin A and Inhibin B were strongly correlated with the growing follicles count. Their concentrations in the high responders group (>18 follicles) were significantly higher (p < 0.00001, p < 0.0001) when compared with normal and low responders (<18 follicles). To suppress the dependence on the growing follicle count, three indices were constructed and calculated. The best association with OHSS status and independence of the growing follicle count was achieved by using the Inhibin B TFF/SBM index calculated as follows: [concentration in FF] × [growing follicle count]/[concentration in serum] × [body mass]. The Inhibin B TFF/SBM index showed a clear difference (p = 0,00433) between the group with severe OHSS and the control group, while showing no apparent correlation with the growing follicle count.</p> <p>Conclusion</p> <p>These observations demonstrated that while neither serum nor FF concentrations of Inhibin A nor Inhibin B can be used as an OHSS predictor independent of the growing follicle count, calculated indices may meet the criteria.</p

FUNCTIONALIZATION OF POLYMERIC NANOFIBERS USING PLATELETS FOR MELANOCYTE CULTURE

Tissue engineering is an interdisciplinary field that uses a combination of cells, suitable biomaterials and bioactive molecules to engineer the desired tissue and restore lost function. These principles have quickly begun to spread to the therapy of multiple diseases, including depigmentation disorders. The most common depigmentation disorder is vitiligo, a disease with deep psychosocial implications. Thanks to their unique properties, electrospun polymeric nanofibers represent a material suitable for tissue engineering applications. Furthermore, they may be functionalized with platelets, cells that contain a wide spectrum of growth factors and chemokines. The aim of this paper was to evaluate the functionalization of polymeric nanofibers with platelets and their effects in melanocyte culture. The scaffolds were visualized using scanning electron microscopy, the metabolic activity and proliferation of melanocytes was determined using MTS assay and dsDNA quantification, respectively. Furthermore, the melanocytes were stained and visualized using confocal microscopy. The acquired data showed that poly-ε-caprolactone functionalized with platelets promoted the viability and proliferation of melanocytes. According to the results, such a functionalized scaffold combining nanofibers and platelets may be suitable for melanocyte culture

Vascular Smooth Muscle Cells (VSMCs) in Blood Vessel Tissue Engineering: The Use of Differentiated Cells or Stem Cells as VSMC Precursors

Vascular smooth muscle cells (VSMCs) play important roles in the physiology and pathophysiology of the blood vessels. In a healthy adult organism, VSMCs are quiescent, but after a blood vessel injury, they undergo phenotypic modulation from the contractile phenotype to the synthetic phenotype, characterized by high activity in migration, proliferation and proteosynthesis. This behavior of VSMCs can lead to stenosis or obliteration of the vascular lumen. For this reason, VSMCs have tended to be avoided in the construction of blood vessel replacements. However, VSMCs are a physiological and the most numerous component of blood vessels, so their presence in novel advanced vascular replacements is indispensable. Either differentiated VSMCs or stem cells as precursors of VSMCs can be used in the reconstruction of the tunica media in these replacements. VSMCs can be obtained from blood vessels (usually from subcutaneous veins) taken surgically from the patients and can be expanded in vitro. During in vitro cultivation, VSMCs lose their differentiation markers, at least partly. These cells should therefore be re-differentiated by seeding them on appropriate scaffolds by composing cell culture media and by mechanical stimulation in dynamic bioreactors. Similar approaches can also be applied for differentiating stem cells, particularly adipose tissue-derived stem cells, toward VSMCs for the purposes of vascular tissue engineering

The Role of Vascular Smooth Muscle Cells in the Physiology and Pathophysiology of Blood Vessels

Vascular smooth muscle cells (VSMCs) play important roles not only in the physiological functions of the blood vessels, such as vasoconstriction, vasodilatation and extracellular matrix production, but also in the pathogenesis of vascular diseases, particularly atherosclerosis and hypertension. VSMCs are mostly of mesodermal origin, although some are of neuroectodermal origin, for example, VSMCs present in the aorta and in blood vessels arising from the aortic arch. VSMCs of neuroectodermal origin are implicated in defects of cardiovascular morphogenesis, such as bicuspid aortic valve, coarctation of the aorta, patent ductus arteriosus and tetralogy of Fallot. The origin, location in the vascular tree, gender, species, strain and age influence the phenotype of VSMCs and their propensity to migration and growth. In a healthy adult organism, VSMCs have a quiescent and differentiated contractile phenotype characterized by early markers (e.g., SM α-actin, SM22-α), intermediate markers (h-caldesmon, calponin) and late markers (SM myosins, smoothelin) of VSMC differentiation. However, after blood vessel injury, surgery or explantation in vitro, VSMCs undergo a phenotypic modulation to synthetic phenotype, which endows them with high activity in migration, growth and proteosynthesis. These features can lead to stenosis or to obliteration of the vascular lumen and impaired blood supply to various tissues and organs

Nanofibrous Scaffolds as Promising Cell Carriers for Tissue Engineering

Nanofibers are promising cell carriers for tissue engineering of a variety of tissues and organs in the human organism. They have been experimentally used for reconstruction of tissues of cardiovascular, respiratory, digestive, urinary, nervous and musculoskeletal systems. Nanofibers are also promising for drug and gene delivery, construction of biosensors and biostimulators, and wound dressings. Nanofibers can be created from a wide range of natural polymers or synthetic biostable and biodegradable polymers. For hard tissue engineering, polymeric nanofibers can be reinforced with various ceramic, metal-based or carbon-based nanoparticles, or created directly from hard materials. The nanofibrous scaffolds can be loaded with various bioactive molecules, such as growth, differentiation and angiogenic factors, or funcionalized with ligands for the cell adhesion receptors. This review also includes our experience in skin tissue engineering using nanofibers fabricated from polycaprolactone and its copolymer with polylactide, cellulose acetate, and particularly from polylactide nanofibers modified by plasma activation and fibrin coating. In addition, we studied the interaction of human bone-derived cells with nanofibrous scaffolds loaded with hydroxyapatite or diamond nanoparticles. We also created novel nanofibers based on diamond deposition on a SiO2 template, and tested their effects on the adhesion, viability and growth of human vascular endothelial cells

Moss biomonitoring of air pollution and assessment of the effects on archeological objects in Stobi, North Macedonia

The contents of 33 elements (Ag, Al, As, B, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Ge, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, Pd, S, Sb, Se, Sn, Sr, Ti, V, and Zn) were determined in moss samples collected from 20 different locations in the ancient town of Stobi, North Macedonia. Determination was performed by the application of inductively coupled plasma with mass spectrometry (ICP-MS) after microwave digestion. It was found that the median values for the content of macroelements (Al, Ca, Fe, K, Mg) and for some specific trace elements (Co, Cr, Cu, Ni, Pb, and Zn) in moss samples from the Stobi site are higher to those obtained for the moss samples collected from the whole territory of North Macedonia. This significant increase in the contents of these elements is especially noticeable in the samples of moss taken from the monuments in Stobi, whose substrate is the mortar between lime and sandstones or sandstone, and in some cases when the substrate is a marble. Similar behavior has been observed also from the data for the median and the range of the content of these elements in the six moss samples collected from the wider vicinity of Stobi which have a noticeable increase in the median values of Ca, Co, Cr, Fe, Ni, Sr, and Zn compared to the median for the samples taken from the entire territory of North Macedonia. It was concluded that the contamination of the moss samples from Stobi, apart from the substrate from which they were taken, is also affected by the distribution of dust from the surrounding soils, in which the content of elements with increased contents is significantly higher than the average for soils from the entire territory of North Macedonia