Search results for "Type I"
showing 10 items of 966 documents
In vitro 30 nm silver nanoparticles promote chondrogenesis of human mesenchymal stem cells
2015
Silver nanoparticles (Ag NPs) are one of the most widely used products in nano-medicine due to their broad-spectrum antimicrobial activity. In tissue engineering, Ag NPs are often incorporated as antibacterial agents in scaffolds, which are subsequently loaded with human bone marrow-derived mesenchymal stem cells (hMSCs). In this study, we investigated the effect of Ag NPs on chondrogenesis of hMSCs. The synthesized Ag NPs were spherical in shape, with a mean diameter of ∼30 nm. After 24 h exposure, Ag NPs were taken up into hMSCs and mainly distributed in the cytoplasm, the nucleus and different sized vesicles. We examined the chondrogenesis through several methods, including glycosaminogl…
Haem oxygenase-1 regulates catabolic and anabolic processes in osteoarthritic chondrocytes
2007
Pro-inflammatory cytokines, matrix metalloproteinases (MMPs) and other catabolic factors participate in the pathogenesis of cartilage damage in osteoarthritis (OA). Pro-inflammatory cytokines such as interleukin-1β (IL-1β) mediate cartilage degradation and might be involved in the progression of OA. Previously, we found that haem oxygenase-1 (HO-1) is down-regulated by pro-inflammatory cytokines and up-regulated by IL-10 in OA chondrocytes. The aim of this study was to determine whether HO-1 can modify the catabolic effects of IL-1β in OA cartilage and chondrocytes. Up-regulation of HO-1 by cobalt protoporphyrin IX significantly reduced glycosaminoglycan degradation elicited by IL-1β in OA …
Haem oxygenase-1 induction reverses the actions of interleukin-1β on hypoxia-inducible transcription factors and human chondrocyte metabolism in hypo…
2013
HO-1 (haem oxygenase-1) catalyses the degradation of haem and possesses anti-inflammatory and cytoprotective properties. The role of inflammatory mediators in the pathogenesis of OA (osteoarthritis) is becoming increasingly appreciated. In the present study, we investigated the effects of HO-1 induction in OA and healthy HACs (human articular chondrocytes) in response to inflammatory cytokine IL-1 β (interleukin-1β) under hypoxic conditions. Hypoxia was investigated as it is a more physiological condition of the avascular cartilage. Hypoxic signalling is mediated by HIFs (hypoxia-inducible factors), of which there are two main isoforms, HIF-1α and HIF-2α. Normal and OA chondrocytes were sti…
Influence of age on osteoarthritis progression after anterior cruciate ligament transection in rats.
2013
Abstract The anterior cruciate ligament transection (ACLT) model of osteoarthritis (OA) in young rats is widely used to study the pathogenesis of OA and possible treatment approaches. As aging is a key factor in the progression of this condition, it is hypothesized that animals may vary in their responses to ACLT according to their age. The histopathological features of young (2 month-old) and middle-aged (12 month-old) rats in the presence or absence of ACLT were compared. The results indicated that moderate degradative changes can be detected in the knee joints of sham-operated middle-aged rats compared with young animals. After ACLT, cartilage degradation was significantly higher in midd…
Regulation of the inflammatory response by tin protoporphyrin IX in the rat anterior cruciate ligament transection model of osteoarthritis
2010
The purpose of this study was to investigate several inflammatory mediators and cartilage degradation molecules as possible biomarkers of joint lesion in the anterior cruciate ligament transection (ACLT) model of osteoarthritis in rats. We also assessed whether the treatment with the anti-inflammatory agent tin protoporphyrin IX (SnPP) reduces the progression of disease. Our results indicate that serum levels of interleukin (IL)-6 and PGE2 are significantly increased in ACLT rats 10 weeks after surgery, whereas the increases in IL-1β and tumor necrosis-α were not significant. In addition, our data suggest that IL-17 is the main pro-inflammatory cytokine in the ACLT joint. We have shown that…
PLLA scaffolds produced by thermally induced phase separation (TIPS) allow human chondrocyte growth and extracellular matrix formation dependent on p…
2016
Damage of hyaline cartilage species such as nasoseptal or joint cartilage requires proper reconstruction, which remains challenging due to the low intrinsic repair capacity of this tissue. Implantation of autologous chondrocytes in combination with a biomimetic biomaterial represents a promising strategy to support cartilage repair. The aim of this work was to assess the viability, attachment, morphology, extracellular matrix (ECM) production of human articular and nasoseptal chondrocytes cultured in vitro in porous poly(L-lactic) (PLLA) scaffolds of two selected pore sizes (100 and 200 μm). The PLLA scaffolds with 100 and 200 μm pore sizes were prepared via ternary thermally induced ph…
Highly porous novel chondro-instructive bioactive glass scaffolds tailored for cartilage tissue engineering
2021
Abstract Cartilage injuries remain challenging since the regenerative capacity of cartilage is extremely low. The aim was to design a novel type of bioactive glass (BG) scaffold with suitable topology that allows the formation of cartilage-specific extracellular matrix (ECM) after colonization with chondrogenic cells for cartilage repair. Highly porous scaffolds with interconnecting pores consisting of 100 % BG were manufactured using a melting, milling, sintering and leaching technique. Scaffolds were colonized with porcine articular chondrocytes (pAC) and undifferentiated human mesenchymal stromal cells (hMSC) for up to 35 days. Scaffolds displayed high cytocompatibility with no major pH …
Phenotypic redifferentiation and cell cluster formation of cultured human articular chondrocytes in a three-dimensional oriented gelatin scaffold in …
2013
Modern tissue engineering strategies comprise three elemental parameters: cells, scaffolds and growth factors. Articular cartilage represents a highly specialized tissue which allows frictionless gliding of corresponding articulating surfaces. As the regenerative potential of cartilage is low, tissue engineering-based strategies for cartilage regeneration represent a huge challenge. Prostaglandins function as regulators in cartilage development and metabolism, especially in growth plate chondrocytes. In this study, it was analyzed if prostaglandin E2 (PGE2) has an effect on the phenotypic differentiation of human chondrocytes cultured in a three-dimensional (3D) gelatin-based scaffold made …
Morphogenetically active scaffold for osteochondral repair (Polyphosphate/alginate/N,O-carboxymethyl chitosan)
2016
Here we describe a novel bioinspired hydrogel material that can be hardened with calcium ions to yield a scaffold material with viscoelastic properties matching those of cartilage. This material consists of a negatively charged biopolymer triplet, composed of morphogenetically active natural inorganic polyphosphate (polyP), along with the likewise biocompatible natural polymers N,O-carboxymethyl chitosan (N,O-CMC) and alginate. The porosity of the hardened scaffold material obtained after calcium exposure can be adjusted by varying the pre-processing conditions. Various compression tests were applied to determine the local (nanoindentation) and bulk mechanical properties (tensile/compressio…
Transcriptional and post-transcriptional regulation of iNOS expression in human chondrocytes
2009
Chondrocytes are important for the development and maintenance of articular cartilage. However, both in osteoarthritis (OA) and rheumatoid arthritis (RA) chondrocytes are involved in the process of cartilage degradation and synthesize important immunomodulatory mediators, including nitric oxide (NO) generated by the inducible NO synthase (iNOS). To uncover the role of iNOS in the pathomechanisms of OA and RA, we analyzed the regulation of iNOS expression using immortalized human chondrocytes as a reproducible model. In C-28/I2 chondrocytes, iNOS expression was associated with the expression of the chondrocyte phenotype. Peak induction by a cytokine cocktail occurred between 6 and 8h and dec…