ABSTRACT
The aim of this study was to evaluate the effects of sodium hyaluronate (HY), single-walled carbon nanotubes (SWCNTs) and HY-functionalized SWCNTs (HY-SWCNTs) on the behavior of primary osteoblasts, as well as to investigate the deposition of inorganic crystals on titanium surfaces coated with these biocomposites. Primary osteoblasts were obtained from the calvarial bones of male newborn Wistar rats (5 rats for each cell extraction). We assessed cell viability using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay and by double-staining with propidium iodide and Hoechst. We also assessed the formation of mineralized bone nodules by von Kossa staining, the mRNA expression of bone repair proteins, and the deposition of inorganic crystals on titanium surfaces coated with HY, SWCNTs, or HY-SWCNTs. The results showed that treatment with these biocomposites did not alter the viability of primary osteoblasts. Furthermore, deposition of mineralized bone nodules was significantly increased by cells treated with HY and HY-SWCNTs. This can be partly explained by an increase in the mRNA expression of type I and III collagen, osteocalcin, and bone morphogenetic proteins 2 and 4. Additionally, the titanium surface treated with HY-SWCNTs showed a significant increase in the deposition of inorganic crystals. Thus, our data indicate that HY, SWCNTs, and HY-SWCNTs are potentially useful for the development of new strategies for bone tissue engineering.
Subject(s)
Animals , Male , Calcification, Physiologic/drug effects , Hyaluronic Acid/pharmacology , Nanotubes, Carbon , Osteoblasts/drug effects , Titanium/metabolism , Apoptosis/drug effects , /metabolism , /metabolism , Cell Survival , Coated Materials, Biocompatible/pharmacology , Collagen Type I/metabolism , Collagen Type III/metabolism , Microscopy, Electron, Scanning , Nanotubes, Carbon/chemistry , Organometallic Compounds/pharmacology , Primary Cell Culture , Rats, Wistar , RNA, Messenger/analysis , RNA, Messenger/metabolism , Spectrometry, X-Ray Emission , Staining and Labeling/methods , Tissue Engineering/methods , Titanium/chemistryABSTRACT
In the present study, we investigated types of pancreatic endocrine cells and its respective peptides in the Brazilian sparrow species using immunocytochemistry. The use of polyclonal specific antisera for somatostatin, glucagon, avian pancreatic polypeptide (APP), YY polypeptide (PYY) and insulin, revealed a diversified distribution in the pancreas. All these types of immunoreactive cells were observed in the pancreas with different amounts. Insulin- Immunoreactive cells to (B cells) were most numerous, preferably occupying the central place in the pancreatic islets. Somatostatin, PPA, PYY and glucagon immunoreactive cells occurred in a lower frequency in the periphery of pancreatic islets.
Os tipos de células endócrinas e seus respectivos peptídeos reguladores foram estudados imunocitoquimicamente no pâncreas do tico-tico, espécie Zonotrichia capensis subtorquata, empregando-se o método imunocitoquímico ABC - Peroxidase (Complexo Avidina - Biotina - Peroxidase) e anti-soros específicos para somatostatina, ao glucagon, ao polipeptídeo pancreático aviário (PPA), ao polipeptídeo YY (PYY) e à insulina. Todos estes tipos de células imunorreativas foram observadas no pâncreas em quantidades diferentes. As células imunorreativas à insulina (células B) foram as mais numerosas, ocupando preferencialmente, a região central das ilhotas pancreáticas. As células endócrinas imunorreativas à somatostatina, PPA, PYY e glucagon localizaram-se predominantemente na periferia das ilhotas.