Search results for "CARTILAGE"

Association between radiography-based subchondral bone structure and MRI-based cartilage composition in postmenopausal women with mild osteoarthritis

2016

Summary Objective Our aim was to investigate the relation between radiograph-based subchondral bone structure and cartilage composition assessed with delayed gadolinium enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T 2 relaxation time. Design Ninety-three postmenopausal women (Kellgren–Lawrence grade 0: n  = 13, 1: n  = 26, 2: n  = 54) were included. Radiograph-based bone structure was assessed using entropy of the Laplacian-based image ( E Lap ) and local binary patterns ( E LBP ), homogeneity indices of the local angles (HI Angles,mean , HI Angles,Perp , HI Angles,Paral ), and horizontal (FD Hor ) and vertical fractal dimensions (FD Ver ). Mean dGEMRIC index and T 2 relax…

Going beyond histology. Synchrotron micro-computed tomography as a methodology for biological tissue characterization: from tissue morphology to indi…

2009

Current light microscopic methods such as serial sectioning, confocal microscopy or multiphoton microscopy are severely limited in their ability to analyse rather opaque biological structures in three dimensions, while electron optical methods offer either a good three-dimensional topographic visualization (scanning electron microscopy) or high-resolution imaging of very thin samples (transmission electron microscopy). However, sample preparation commonly results in a significant alteration and the destruction of the three-dimensional integrity of the specimen. Depending on the selected photon energy, the interaction between X-rays and biological matter provides semi-transparency of the spe…

2020

Cilia are cellular organelles that project from the cell. They occur in nearly all non-hematopoietic tissues and have different functions in different tissues. In mesenchymal tissues primary cilia play a crucial role in the adequate morphogenesis during embryological development. In mature articular cartilage, primary cilia fulfil chemo- and mechanosensitive functions to adapt the cellular mechanisms on extracellular changes and thus, maintain tissue homeostasis and morphometry. Ciliary abnormalities in osteoarthritic cartilage could represent pathophysiological relationships between ciliary dysfunction and tissue deformation. Nevertheless, the molecular and pathophysiological relationships…

Enzymatically Synthesized Inorganic Polymers as Morphogenetically Active Bone Scaffolds

2014

In recent years a paradigm shift in understanding of human bone formation has occurred that starts to change current concepts in tissue engineering of bone and cartilage. New discoveries revealed that fundamental steps in biomineralization are enzyme driven, not only during hydroxyapatite deposition, but also during initial bioseed formation, involving the transient deposition and subsequent transformation of calcium carbonate to calcium phosphate mineral. The principal enzymes mediating these reactions, carbonic anhydrase and alkaline phosphatase, open novel targets for pharmacological intervention of bone diseases like osteoporosis, by applying compounds acting as potential activators of …

κ-Carrageenan and PVA blends as bioinks to 3D print scaffolds for cartilage reconstruction.

2022

3D printing of polymeric scaffolds and autologous stem cells is a promising tool for damaged facial cartilage reconstruction surgeries. To this end, suitable bioinks are needed to generate scaffolds with the required morphological and functional features. We formulated hydrogel bioinks using k-Carrageen (kC) and poly(vinyl alcohol) (PVA) in three different weight ratios. The kC gives the systems the ability to undergo rapid sol-to-gel transitions upon cooling from 60 °C and above to body temperature, while the PVA is used as rheology modifier and porogen. The latter is crosslinked after molding or printing by freeze-thaw cycling for 1 day (FT1) or 5 days (FT5). To select the most suitable f…

Implantation of a polycaprolactone scaffold with subchondral bone anchoring ameliorates nodules formation and other tissue alterations

2015

Purpose: Articular cartilage has limited repair capacity. Two different implant devices for articular cartilage regeneration were tested in vivo in a sheep model to evaluate the effect of subchondral bone anchoring for tissue repair. Methods: The implants were placed with press-fit technique in a cartilage defect after microfracture surgery in the femoral condyle of the knee joint of the sheep and histologic and mechanical evaluation was done 4.5 months later. The first group consisted of a biodegradable polycaprolactone (PCL) scaffold with double porosity. The second test group consisted of a PCL scaffold attached to a poly(L-lactic acid) (PLLA) pin anchored to the subchondral bone. Result…

Profilin 1 is required for abscission during late cytokinesis of chondrocytes

2009

Profilins are key factors for dynamic rearrangements of the actin cytoskeleton. However, the functions of profilins in differentiated mammalian cells are uncertain because profilin deficiency is early embryonic lethal for higher eukaryotes. To examine profilin function in chondrocytes, we disrupted the profilin 1 gene in cartilage (Col2pfn1). Homozygous Col2pfn1 mice develop progressive chondrodysplasia caused by disorganization of the growth plate and defective chondrocyte cytokinesis, indicated by the appearance of binucleated cells. Surprisingly, Col2pfn1 chondrocytes assemble and contract actomyosin rings normally during cell division; however, they display defects during late cytokines…

Wharton’s Jelly Mesenchymal Stem Cells for the Treatment of Type 1 Diabetes

2014

Type 1 diabetes is an autoimmune disease caused by the destruction of endocrine pancreas β cells by T lymphocytes, for which genetic and environmental risk factors have been proposed. Patients require daily infusions of recombinant insulin to overcome the reduced production by their own cells, but there is an increasing demand for a permanent and efficient supplementation which could better modulate the need for the hormone during the normal activities. For this reason, transplant-based therapeutic models have been proposed such as whole organ transplantation and Langerhans islets transplantation. These techniques are limited by many factors such as the lack of donors, the risks linked to t…

The expression of CD68 in human umbilical cord mesenchymal stem cells: new evidences of presence in non-myeloid cell types.

2009

Since their first identification in bone marrow [2],MSC have attracted much attention for thei r potential todifferentiate towards several mature tissues. The efforts ofthe researchers aimed in finding new tissues, whichshould provide adequate cell numbers for regenerativemedicine applications (and between them, extraembryonicsources as umbilical cord and amniotic membrane, arebeing viewed with extreme interest).

Umbilical cord versus bone marrow-derived mesenchymal stromal cells.

2012

incetheplacentaisapostnatal tissue and discarded asmedical waste, harvesting stem cells from this organrepresents a noninvasive and ethically conductive proce-dure. Perinatal stem cells isolated from amnion, chorion,umbilical cord, and cord blood are increasingly viewedas reliable sources of mesenchymal stromal cells (MSCs)alternative to bone marrow-derived ones (BM-MSCs),which are currently the most commonly used in clinicalapplications [1–5].Perinatal stem cells are a bridge between embryonic stemcells (ESCs) and adult stem cells (such as BM-MSCs). Theyshare many characteristics of both cells [1,6]. Considering thestructural complexity of the term ‘‘placenta,’’ we have fo-cused our attent…