Uticaj različitih 3D biomaterijala na osteoblastnu diferencijaciju mezenhimalnih ćelija zubne pulpe

Millions of patients worldwide suffer from bone disease or bone defects such as osteosarcoma, osteoporosis and bone fractures. In order to solve the problem of lost bone tissue, bone tissue engineering major emphasis is on tissue regeneration rather than tissue replacement, which is why it became the subject of growing interest. Stem cells and scaffolds have an essential role in the production of new tissue by tissue engineering. Cellular component is necessary for the generation and establishment of the extracellular matrix in new tissue, while scaffold is responsible for providing mechanical stability and the foundation of a new three-dimensional tissue organization. The main objective of the dissertation was to examine the differential capacity of isolated dental pulp mesenchymal cells in relation to 4 different cell carriers - scaffolds: porous hydroxyapatite (pHAP) and porous hydroxyapatite combined with 3 polymers: poly lactic-co-glycolic acid (PLGA), alginate and ethylene vinyl acetate / ethylene vinyl versatate (EVA / EVV). The research involved the isolation of dental pulp mesenchymal cells from human exfoliated deciduous teeth shift by "outgrowth" method and their characterization by flow cytometry. Characterization of synthesized biomaterials was performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and methods of the specific surface area of hydroxyapatite powder (BET method). Cytotoxicity of biomaterials in the presence of mesenchymal cells was tested by an indirect method using the MTT test and by a direct method using the LDH test. Evaluation of osteogenic differentiation of isolated mesenchymal cells on 3D biomaterials samples was performed by alizarin red staining, alkaline phosphatase activity measurements and scanning electron microscopy. The differentiation of isolated dental pulp cells in 3 different cell types - adipocytes, chondrocytes and osteoblasts, and characterization of these cells by CD29, CD73, CD90 and CD34 antibodies, showed the isolated cells were mesenchymal stem cells...Milioni pacijenata širom sveta pate od oboljenja kostiju ili koštanih defekata kao što su osteosarkom, osteoporoza i frakture kostiju. U cilju rešavanja problema izgubljenog koštanog tkiva, inženjerstvo koštanog tkiva glavni akcenat stavlja na tkivnu regeneraciju a ne na zamenu tkiva, zbog čega postaje predmet sve većeg interesovanja. Matične ćelije i skafoldi imaju esencijalnu ulogu u stvaranju novog tkiva putem tkivnog inženjerstva. Ćelijska komponenta je neophodna zbog stvaranja i uspostavljanja ekstracelularnog matriksa u novom tkivu, dok su skafoldi zaduženi za obezbeđivanje mehaničke stabilnosti i temelja trodimenzionalne organizacije novog tkiva. Osnovni cilj doktorske disertacije bio je ispitati diferencijalni kapacitet izolovanih mezenhimalnih ćelija zubne pulpe u odnosu na 4 različita ćelijska nosača – skafolda: poroznog hidroksiapatita (pHAP) i poroznog hidroksiapatita u kombinaciji sa 3 polimera: polilaktid-koglikolnom kiselina (PLGA), alginatom i polimerom etilen vinil acetat/versatatom (EVA/EVV). Istraživanje je podrazumevalo izolovanje mezenhimalnih ćelija zubne pulpe poreklom iz mlečnih zuba u fiziološkoj smeni “outgrowth” metodom i njihovu karakterizaciju metodom protočne citometrije. Sintetisani biomaterijali su okarakterisani uz pomoć Fourier transform infracrvene spektroskopije (FTIR), rentgen difrakcije (XRD), mikroskopije atomskih sila (AFM), skening elektronske mikroskopije (SEM) i metode analize specifične površine čestice praha hidroksiapatita (BET metoda). Citotksičnost biomaterijala u prisustvu mezenhimalnih ćelija je ispitivana indirektnom metodom pomoću MTT testa i direktnom metodom pomoću LDH testa. Osteogena diferencijacija izolovanih mezenhimalnih ćelija u prisustvu različitih 3D biomaterijala praćena je bojenjem uzoraka alizarin crvenim, merenjem aktivnosti alkalne fosfataze i skening elektronskom mikroskopijom. Diferencijacijom ćelija u 3 različite vrste ćelija – adipocite, hondrocite i osteoblaste, i karakterizacijom CD29, CD73, CD90 i CD34 antitelima, pokazano je da su izolovane ćelije iz zubne pulpe mezenhimalne matične ćelije. Takođe, rezultati istraživanja pokazuju da su ispitivani skafoldi bili adekvatno dizajnirani i da su imali odgovarajuću morfologiju površine koja je neophodna za ćelijske nosače..

Effects of various 3D biomaterials on osteoblastic differentiation of dental pulp mesenchymal cells

Milioni pacijenata širom sveta pate od oboljenja kostiju ili koštanih defekata kao što su osteosarkom, osteoporoza i frakture kostiju. U cilju rešavanja problema izgubljenog koštanog tkiva, inženjerstvo koštanog tkiva glavni akcenat stavlja na tkivnu regeneraciju a ne na zamenu tkiva, zbog čega postaje predmet sve većeg interesovanja. Matične ćelije i skafoldi imaju esencijalnu ulogu u stvaranju novog tkiva putem tkivnog inženjerstva. Ćelijska komponenta je neophodna zbog stvaranja i uspostavljanja ekstracelularnog matriksa u novom tkivu, dok su skafoldi zaduženi za obezbeđivanje mehaničke stabilnosti i temelja trodimenzionalne organizacije novog tkiva. Osnovni cilj doktorske disertacije bio je ispitati diferencijalni kapacitet izolovanih mezenhimalnih ćelija zubne pulpe u odnosu na 4 različita ćelijska nosača – skafolda: poroznog hidroksiapatita (pHAP) i poroznog hidroksiapatita u kombinaciji sa 3 polimera: polilaktid-koglikolnom kiselina (PLGA), alginatom i polimerom etilen vinil acetat/versatatom (EVA/EVV). Istraživanje je podrazumevalo izolovanje mezenhimalnih ćelija zubne pulpe poreklom iz mlečnih zuba u fiziološkoj smeni “outgrowth” metodom i njihovu karakterizaciju metodom protočne citometrije. Sintetisani biomaterijali su okarakterisani uz pomoć Fourier transform infracrvene spektroskopije (FTIR), rentgen difrakcije (XRD), mikroskopije atomskih sila (AFM), skening elektronske mikroskopije (SEM) i metode analize specifične površine čestice praha hidroksiapatita (BET metoda). Citotksičnost biomaterijala u prisustvu mezenhimalnih ćelija je ispitivana indirektnom metodom pomoću MTT testa i direktnom metodom pomoću LDH testa. Osteogena diferencijacija izolovanih mezenhimalnih ćelija u prisustvu različitih 3D biomaterijala praćena je bojenjem uzoraka alizarin crvenim, merenjem aktivnosti alkalne fosfataze i skening elektronskom mikroskopijom. Diferencijacijom ćelija u 3 različite vrste ćelija – adipocite, hondrocite i osteoblaste, i karakterizacijom CD29, CD73, CD90 i CD34 antitelima, pokazano je da su izolovane ćelije iz zubne pulpe mezenhimalne matične ćelije. Takođe, rezultati istraživanja pokazuju da su ispitivani skafoldi bili adekvatno dizajnirani i da su imali odgovarajuću morfologiju površine koja je neophodna za ćelijske nosače...Millions of patients worldwide suffer from bone disease or bone defects such as osteosarcoma, osteoporosis and bone fractures. In order to solve the problem of lost bone tissue, bone tissue engineering major emphasis is on tissue regeneration rather than tissue replacement, which is why it became the subject of growing interest. Stem cells and scaffolds have an essential role in the production of new tissue by tissue engineering. Cellular component is necessary for the generation and establishment of the extracellular matrix in new tissue, while scaffold is responsible for providing mechanical stability and the foundation of a new three-dimensional tissue organization. The main objective of the dissertation was to examine the differential capacity of isolated dental pulp mesenchymal cells in relation to 4 different cell carriers - scaffolds: porous hydroxyapatite (pHAP) and porous hydroxyapatite combined with 3 polymers: poly lactic-co-glycolic acid (PLGA), alginate and ethylene vinyl acetate / ethylene vinyl versatate (EVA / EVV). The research involved the isolation of dental pulp mesenchymal cells from human exfoliated deciduous teeth shift by "outgrowth" method and their characterization by flow cytometry. Characterization of synthesized biomaterials was performed by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and methods of the specific surface area of hydroxyapatite powder (BET method). Cytotoxicity of biomaterials in the presence of mesenchymal cells was tested by an indirect method using the MTT test and by a direct method using the LDH test. Evaluation of osteogenic differentiation of isolated mesenchymal cells on 3D biomaterials samples was performed by alizarin red staining, alkaline phosphatase activity measurements and scanning electron microscopy. The differentiation of isolated dental pulp cells in 3 different cell types - adipocytes, chondrocytes and osteoblasts, and characterization of these cells by CD29, CD73, CD90 and CD34 antibodies, showed the isolated cells were mesenchymal stem cells..

Biological aspects of application of nanomaterials in tissue engineering

Millions of patients worldwide need surgery to repair or replace tissue that has been damaged through trauma or disease. To solve the problem of lost tissue, a major emphasis of tissue engineering (TE) is on tissue regeneration. Stem cells and highly porous biomaterials used as cell carriers (scaffolds) have an essential role in the production of new tissue by TE. The cellular component is important for the generation and establishment of the extracellular matrix, while a scaffold is necessary to determine the shape of the newly formed tissue and facilitate migration of cells into the desired location, as well as their growth and differentiation. This review describes the types, characteristics and classification of stem cells. Furthermore, it includes functional features of cell carriers - biocompatibility, biodegradability and mechanical properties of biomaterials used in developing state-of-the-an scaffolds for TE applications, as well as suitability for different tissues. Moreover, it explains the importance of nanotechnology and defines the challenges and the purpose of future research in this rapidly advancing field

Polinezasićene masne kiseline u zdravlju i bolesti

Polyunsaturated fatty acids (PUFAs) are necessary for overall health. Two PUFAs families, n-6 and n-3 fatty acids, are physiologically and metabolically distinct. The proportion of PUFAs in serum and erythrocyte phospholipids, which depends on endogenous metabolism controlled by genetic polymorphisms and dietary intake, is an important determinant of both health and disease. Both n-3 and n-6 PUFAs are processed to powerful promoters of eicosanoids synthesis at the cyclooxygenase and lipoxygenase level. Evidence from observational and intervention studies suggest that n-3 PUFAs are cardio-protective, perhaps through their anti-inflammatory, anti-arrhythmic, lipid-low­ering and antihypertensive effects. In contrast, dietary n-6 PUFAs have pro-inflammatory effects. Low n-3 and elevated n-6 PUFAs levels were found in patients with cancer on different sites. The present review focuses on current knowledge related to PUFAs intake and status in health and disease, with reference to the Serbian population.Polinezasićene masne kiseline (PMK) su neophodne za normalno funkcionisanje organizma. Dve PMK familije, n-6 i n-3 masne kiseline se fiziološki i metabolički razlikuju. Udeo PMK u fosfolipidima seruma i eritrocita je važan pokazatelj zdravlja i bolesti, i zavisi od endogenog metabolizma, koji je kontrolisan genetskim polimorfizmom, i unosa hrane. I n-6 i n-3 PMK su prekursori za sintezu eikozanoida na ciklooksigenaznom i lipooksigenaznom nivou. Opservacione i interventne studije ukazuju da n-3 PMK imaju kardioprotektivni efekat, delujući anti-inflamatorno, anti-aritmogeno, hipolipidemično i antihipertenzivno. Nasuprot tome, smatra se da n-6 PMK imaju pro-inflamatorno dejstvo. Nizak nivo n-3 i povišen udeo n-6 PMK je pokazan kod pacijenata sa različitim tipovima maligniteta. U okviru ovog rada dat je pregled najnovijih saznanja o dijetarnom unosu i biomarkerima statusa PMK u promociji zdravlja i prevenciji bolesti, sa posebnim osvrtom na rezultate u našoj populaciji

Potential preservation of dental pulp stem cells

Dental pulp stem cells (DPSCs) as postnatal stem cells have recently been described. They are clonogenic cells, capable for self-renewal with high proliferative potential. Their multilineage potential and plasticity enables their differentiation into different kind of cells, such as osteoblasts, chondrocytes, adipocytes, muscle cells, neural cells, odontoblasts, cementoblasts and ameloblasts. DPSCs are an important human stem cells source, especially in patients who lost their chance for umbilical cord blood isolation and preservation. As these cells became useful for tissue engineering and cell therapy, proper mode of their preservation also became important. The most important points in the cryopreservation and recovery procedure are: growth phase of harvested cells, number of cells, the proper cryopreservative concentration and serum concentration. The cryopreservation process includes the following general components: harvesting of the cells, addition of cryopreservative, the freezing procedure, the thawing procedure and assessment of the viability prior to transplantation. There is no single and perfect cryopreservation method. Further investigations should be regarding capability of DPSCs and their differentiated cells to recover and restart proliferation, differentiation and new tissue production for therapeutic use after cryopreservation

The effect of meteorological and chemical parameters on summer phytoplankton assemblages in an urban recreational lake

The summer phytoplankton community was studied across both vertical and temporal scales in relation to environmental factors in the shallowrecreational Sava Lake. The sampling was conducted weekly at four depths from mid-July until mid-September 2014, in order to detect short-term changes within the assemblages. Besides physical and chemical parameters, meteorological data was also included in the investigation, as that year was characterized with extreme rainfall, which caused serious flooding in the region. The community succession was characterized by a reverse in the cyanobacteria (Codon M) and chlorococcal green algae (Coda F and J). Statistical analyses (RDA) indicated that changes in the community composition and successional pattern could have been due to the mixing regime variations in the reservoir, most likely induced by weather disturbances, especially high precipitation and wind events. These events did not permit massive cyanobacterial development, although they most likely caused resuspension of dissolved phosphorus from the sediment. When observing functional groups, three groups could be distinguished by their response to the above-mentioned parameters: the first prefers high temperature and insolation(Lm, Y, Lo, Xph, W2andM), the second is correlated with precipitation and wind (Td, C, K, MP and X2), while the third group tolerates cloudiness (H1, F, N, X1, D, J and P)

Comparison of Custodiol® and modified St. Thomas cardioplegia for myocardial protection in coronary artery bypass grafting

Background/Aim. Custodiol® is a hyperpolarizing cardioplegic solution which has been used in our national cardiac surgical practice exclusively for the heart transplant surgery. Owing to its numerous advantages over the standard depolarizing solutions, Custodiol® became cardioplegic solution of choice for all other cardiac surgical procedures in many cardio-surgical centers. This study evaluated myocardial protection by Custodiol® compared to modified St. Thomas cardioplegic solution in coronary artery bypass surgery. Methods. In a prospective four-month study, 110 consecutive adult patients who underwent primary isolated elective on-pump coronary artery bypass grafting (CABG) were randomized into the Custodiol® group (n = 54) and the St. Thomas groupa (n = 50), based on the type of administered cardioplegia; six patients were excluded. Cardiac protection was achieved as antegrade cold crystalloid cardioplegia by one of the solutions. Myocardial preservation was assessed through following outcomes: spontaneous rhythm restoration post cross-clamp, and postpoperative cardiac specific enzymes level, ejection fraction (EF) change, inotropic support, myocardial infarction (MI), atrial fibrillation (AF), and death. Results. Preoperative and intraoperative characteristics of patients in both groups were similar except for a considerably longer cross-clamp time in the Custodiol® group (49.1 ± 19.0 vs. 41.0 ± 12.9 minutes; p = 0.022). The Custodiol® group exhibited a higher rate of return to spontaneous rhythm compared to the St. Thomas group (31.5% vs. 20.0%, respectively; p = 0.267), lower rates of AF (20.4% vs. 28%, respectively; p = 0.496), MI (1.8% vs. 10.0%, respectively; p = 0.075) and inotropic support (9.0% vs. 12.0%, respectively; p = 0.651), albeit not statistically significant. There was an insignificant difference in peak value of troponin I between the Custodiol® and Thee St. Thomas group (5.0 ± 3.92 μg/L vs. 4.5 ± 3.39 μg/L, respectively; p = 0.755) and creatine kinase-MB (26.9 ± 15.4 μg/L vs. 28.5 ± 24.2 μg/L, respectively; p = 0.646) 6 hours post-surgery. EF reduction was comparable (0.81% vs. 1.26%; p = 0.891). There were no deaths in both groups. Conclusions. Custodiol® and modified St.Thomas cardioplegic solution have comparable cardioprotective effects in CABG surgery. The trends of less frequent MI, AF and ino-tropic support, despite the longer cross-clamp time in the Custodiol® group may suggest that its benefits could be ascertained in a larger study

Nanomaterials as scaffolds in bone tissue engineering in dental medicine

Traditional strategies for skeletal regeneration in the orofacial region involve the use of autogenous and allogenic bone grafts that may not always be available or safe. One alternative is to develop materials for use as scaffolds for tissue engineering. These calcium-phosphate-based materials are porous, have a large surface area to volume ratio, and can be used to deliver drugs or cells. This enables the development of scaffolds for applications in tissue engineering and bone regeneration. Nanostructured materials promote greater amounts of specific protein interactions and more efficiently stimulate new bone formation. When features of scaffolds are nanoscaled, a variety of interactions can be stimulated at the cellular level. The main requirements for bone tissue engineering scaffolds are discussed, as well as the main types and design strategies. The mechanism by which nanomaterials promote bone formation is explained and the current research status of main types of nanostructured scaffolds is reviewed