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PubMed1999

Secretion of tissue inhibitors of matrix metalloproteinases by human fetal membranes, decidua and placenta at parturition.

At parturition, breakdown of extracellular matrix in the fetal membranes may play a part in the rupture of the membranes and in the aetiology of premature rupture, in addition to having a regulatory role in the cell-cell interactions and signalling at the feto-maternal interface to stimulate myometrial contractility. The matrix metalloproteinases (MMPs) are important enzymes for the breakdown of extracellular matrix and their activity is regulated by a family of endogenous inhibitors, the tissue inhibitors of matrix metalloproteinases (TIMPs). At parturition, alteration in the balance between MMPs and TIMPs may mediate this extracellular matrix breakdown during rupture of fetal membranes. The aims of this study were to determine if the intrauterine secretion of TIMPs changes at labour, and to characterise their cellular sources. A broad range of TIMP activities (27-30 kDa, 24 kDa and 21 kDa) were detected by reverse zymography in term amniotic fluid. There was a significant (P<0.05) decrease in the amount of TIMPs in amniotic fluid and their release with the onset of labour. The TIMPs were characterised by immunoblot as TIMPs-1, -2, -3 and -4. High levels of TIMPs were secreted by explants of chorio-decidua, decidua parietalis and placenta, with less being released by amnion. Immunolocalisation studies revealed a specific distribution pattern for each of the TIMP isoforms. Trophoblast cells of chorion laeve, decidua parietalis and placental syncytiotrophoblast demonstrated specific immunoreactivity for all four isoforms. TIMPs were also found bound to selective regions of extracellular matrix. The decrease in TIMPs during labour may permit increased breakdown of extracellular matrix in the fetal membranes and decidua at parturition, thus altering cell signalling at the feto-maternal interface and facilitating membrane rupture.

Amniotic Fluid↗
PubMed1992

Cytoskeletal architecture of the matrix cell and neuroblast in the neural tube of the chick embryo.

Cytoskeletal architecture of the matrix cell and neuroblast in the wall of midbrain of 4-6 day-old chick embryos was examined by electron microscopy and immunohistochemistry. The matrix cell, the undifferentiated stem cell later producing neurons and glial cells in the central nervous system, is characterized ultrastructurally by abundant free ribosomes and a poorly developed cytomembrane system. A few microtubules running in random directions are observed in the matrix cell body. In the cell processes, microtubules are oriented longitudinally, and linked with each other by cross-bridges, presumably composed of microtubule-associated proteins (MAPs). The cell processes contain abundant cytoplasmic filaments including a large amount of actin filaments which adhere to the plasma membrane of junctional complexes located immediately below the inner surface of the neural tube. In the neuroblast which has been differentiated from the matrix cell, the cytomembranous organelles, especially rough endoplasmic reticulum are markedly better developed than in the matrix cell; microtubules are more numerous in the cell body. The cell process contains many microtubules with cross-bridges and a few intermediate filaments, which are relatively characteristic of the cytoskeleton of the neuroblast. Phalloidin-staining and immunohistochemistry showed that the neuroblast was richer in F-actin, beta-tubulin, MAP1, MAP2, tau, calspectin, and synapsin I than the matrix cell. As the matrix cell differentiates into the neuroblast, both the cytoskeletal and cytomembranous systems proved to develop features, characteristic of a neuron.

Animals↗
PubMed1975

Electron microscopic study of early formation of the tooth enameloid of a fish (Hoplognathus fasciatus). I. Odontoblasts and matrix fibers.

An electron microscope study was made on the tooth germs of Hoplognathus fasciatus in early developmental stage. Special attention was given to the odontoblasts, enameloid matrix fibers, calcification of enameloid and the hitherto controversial origin of the enameloid. 1. The ameloblasts and the odontoblasts are demarcated by a single layer of basement membrane which persists until immediately before the calcification of the enameloid matrix. 2. This histogenesis of the enameloid matrix begins with the formation of non-striated fibers 140-180 A thick. They are arranged in a direction vertical to the basement membrane and parallel to the sides of odontoblasts. Fibers with regular cross striations of 640 A periodicity later appear and the entire enameloid matrix is formed by these fibers. 3. Along with the formation of the enameloid, the odontoblasts assume a high columnar form, with a marked increase in cell organelles which show marked polarity suggesting active protein synthesis. Numerous odontoblastic processes are noted in the enameloid matrix. Granules, representing precurosors of enamleoid matrix fibers occur in the odontoblasts. Based on these findings, the enameloid matrix fibers must be of mesodermal origin. 4. Deposition of crystals of small size, needle and tube in shape, occurs in the circumference of the fiber bundles. As calcification progresses, crystals appear in the central portion of the bundles. Later, large crystals of rod and platelet shapes become intermingled. In addition to this, small crystals are fused, forming aggregates.

Ameloblasts↗
PubMed2006

Forecasting extinction risk with nonstationary matrix models.

Matrix population growth models are standard tools for forecasting population change and for managing rare species, but they are less useful for predicting extinction risk in the face of changing environmental conditions. Deterministic models provide point estimates of lambda, the finite rate of increase, as well as measures of matrix sensitivity and elasticity. Stationary matrix models can be used to estimate extinction risk in a variable environment, but they assume that the matrix elements are randomly sampled from a stationary (i.e., non-changing) distribution. Here we outline a method for using nonstationary matrix models to construct realistic forecasts of population fluctuation in changing environments. Our method requires three pieces of data: (1) field estimates of transition matrix elements, (2) experimental data on the demographic responses of populations to altered environmental conditions, and (3) forecasting data on environmental drivers. These three pieces of data are combined to generate a series of sequential transition matrices that emulate a pattern of long-term change in environmental drivers. Realistic estimates of population persistence and extinction risk can be derived from stochastic permutations of such a model. We illustrate the steps of this analysis with data from two populations of Sarracenia purpurea growing in northern New England. Sarracenia purpurea is a perennial carnivorous plant that is potentially at risk of local extinction because of increased nitrogen deposition. Long-term monitoring records or models of environmental change can be used to generate time series of driver variables under different scenarios of changing environments. Both manipulative and natural experiments can be used to construct a linking function that describes how matrix parameters change as a function of the environmental driver. This synthetic modeling approach provides quantitative estimates of extinction probability that have an explicit mechanistic basis.

Adaptation, Physiological↗
PubMed2003

The effect of enamel matrix proteins on periodontal regeneration as determined by histological analyses.

BACKGROUND: Therapeutic approaches to periodontal regeneration in the past have utilized bone replacement grafts, growth factors, barrier membranes, or combinations of these approaches. More recently, enamel extracellular matrix proteins have been introduced to stimulate periodontal regeneration. One factor thought to have an impact on the outcome of the regenerative process is the initial size of the periodontal defect. This is particularly the case when using proteins to stimulate regeneration, because the concepts of guided tissue regeneration emphasize the need for space maintenance to allow for selected cell repopulation. The goal of this study was to evaluate periodontal regeneration in intrabony defects of various sizes treated with enamel matrix proteins. METHODS: Periodontal defects ranging in size from 1 to 6 mm were created bilaterally around 3 teeth in the mandibles of baboons. Plaque was allowed to accumulate around ligatures placed into the defects. After 2 months, the ligatures were removed, the teeth were scaled and root planed, and a notch was placed at the base of the defect. On one side of the mandible, neutral ethylene diamine tetracetic acid and enamel matrix proteins were used to treat the defects. The other side served as a control, with neutral ethylene diamine tetracetic acid treatment alone after scaling and root planing. Flaps were sutured and the animals were allowed to heal without oral hygiene procedures. After 5 months, the animals were sacrificed and the teeth were processed for histological evaluation. RESULTS: Periodontal regeneration occurred in all sizes of the periodontal defects. Qualitatively, new cementum, periodontal ligament with Sharpey's fibers, and new bone tissue were observed. In general, enamel matrix protein treatment resulted in greater tissue formation than controls. In many instances, dramatic tissue formation occurred far coronal to the base of the defects. In addition, horizontal bone fill occurred in defects that were initially 4 or 6 mm wide. The resultant width of the periodontal ligament was similar in all defects regardless of the original defect width. The cementum width was slightly greater in the wider (4 and 6 mm) defects compared to the more narrow (1 and 2 mm) defects. When evaluating the combined 1 and 2 mm defects, the height of new cementum with enamel matrix protein treatment was 45% greater than the control, with 31% greater new bone height versus the control. In the combined wider defects (4 and 6 mm), new tissue height was more similar between enamel matrix protein-treated defects and control defects. The results from the wider defects must be interpreted cautiously, because the interproximal bone heights were resorbed more adjacent to the wider defects during the plaque accumulation period and likely limited the potential for regeneration. CONCLUSIONS: The treatment of various sized periodontal defects with enamel matrix proteins stimulated substantial periodontal regeneration. In many cases, dramatic amounts of new cementum, Sharpey's fibers, periodontal ligament, and bone tissue were formed far coronal to the notch at the base of the defect, especially considering the width of the original defects. This periodontal regeneration occurred in the absence of exogenous growth factors, bone replacement grafts, barrier membranes, or their combination.

Alveolar Bone Loss↗
PubMed2005

Healing of a critical-sized defect in the rat femur with use of a vascularized periosteal flap, a biodegradable matrix, and bone morphogenetic protein.

BACKGROUND: The purpose of this study was to evaluate the osseous healing of a critical-sized femoral defect in a rat model with use of recombinant human bone morphogenetic protein-2 (rhBMP-2), a matrix fabricated of D,D-L,L-polylactic and hyaluronan acid (OPLA-HY), and a vascularized periosteal flap. METHODS: The carrier matrix OPLA-HY with or without rhBMP-2 was implanted in a 1-cm-long femoral defect and secured with a plate and screws. In some groups, a vascularized periosteal flap was harvested from the medial surface of the tibia. In group 1, the femoral defects in the animals were filled with the OPLA-HY matrix alone; in group 2, the OPLA-HY matrix was covered by the vascularized periosteal flap; in group 3, 20 mug of rhBMP-2 was added to the OPLA-HY matrix; and in group 4, the femoral defect containing the OPLA-HY matrix and 20 mug of rhBMP-2 was wrapped circumferentially by the vascularized periosteal flap. The presence and density of new bone formation in the femoral defect were evaluated radiographically, histologically, and with histomorphometry at four and eight weeks postoperatively. RESULTS: Groups 1 and 2, which were not treated with rhBMP-2, showed no radiographic or histologic evidence of mature bone formation at four or eight weeks. Both groups 3 and 4, which were treated with rhBMP-2, demonstrated excellent bone formation. However, with the periosteal flap, group 4 demonstrated more bone formation on histomorphometric analysis at eight weeks (43.1%) than did group 3 (28.3%) (p < 0.01). Additionally, heterotopic bone formed outside the boundaries of the defect in eight of the fifteen animals in group 3, which had no periosteal flap. CONCLUSIONS: Bone-tissue engineering with use of the OPLA-HY matrix and rhBMP-2 produced good bone formation in the rat femoral defect model. However, the addition of a vascularized periosteal flap significantly increased bone formation within the boundaries of the defect and prevented heterotopic ossification.

Animals↗
PubMed1991

Non-mucin proteins in the matrix of human cholesterol gallstones.

Human cholesterol gallstones contain a pigmented organic matrix that may originate from biliary sludge. The cholesterol gallstone matrix contains mucin, bile pigments, and calcium salts. The goal of this study was to examine whether non-mucin proteins are present in the matrix of cholesterol gallstones. Matrix was prepared from cholesterol gallstones from 18 patients. Proteins were identified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and by molecular sieve high-performance liquid chromatography (HPLC). Two proteins were present in each gallstone and migrated with or just adjacent to standards of bovine serum albumin on SDS-PAGE. Several additional lower molecular weight proteins were identified, but not in every gallstone. Protein fractions contained visible pigment after chloroform extraction, and pigment co-eluted with proteins on HPLC, suggesting binding of pigments to proteins in the matrix. We conclude that low molecular weight proteins are present in the cholesterol gallstone matrix. The major protein appears to be serum albumin, although definitive identification has not been established. The origin of these matrix proteins and their possible significance in the pathogenesis of cholesterol cholelithiasis is unknown.

Bilirubin↗
PubMed1990

[Matrix vesicles in membranous ossification].

Calcification process in membranous ossification was examined histologically by light and electron microscopies in comparison with that in enchondral ossification. The following results were obtained: 1) In the rat tibial articular cartilage, the extracellular matrix proceeding from the transitional to the hypertrophic zone consisted of the following three layers from the proximal: the first layer in which ruthenium red positive granules were densely populated and thin collagen fibrils diffusely arranged but few matrix vesicles were observed; the second one containing numerous matrix vesicles and slightly thick collagen fibrils; and the last one in which the thick collagen fibrils were observed while matrix vesicles and ruthenium red positive granules were few. 2) In the calcified regions in the extracellular matrix of MC3T3-E1 cells, the regions of alveolar new bone formation due to orthodontic tooth movement and the calcified regions in the interparietal suture expanded mechanically in vitro, the number of matrix vesicles was less than those in the regions of enchondral ossification. 3) Ruthenium red positive granules were fewer in the regions of alveolar new bone formation after the orthodontic tooth movement than in the calcified regions of cartilage. 4) The observation on MC3T3-E1 cells revealed the two different possibilities of the processes of calcification: the calcification induced by matrix vesicles as an initiator and that directly related to mineral deposit on the collagen fibrils.

Alveolar Process↗
PubMed1990

Using matrix organization to manage health care delivery organizations.

Matrix organization can provide health care organization managers enhanced information processing, faster response times, and more flexibility to cope with greater organization complexity and rapidly changing operating environments. A review of the literature informed by work experience reveals that the use of matrix organization creates hard-to-manage ambiguity and balances of power in addition to providing positive benefits for health care organization managers. Solutions to matrix operating problems generally rely on the use of superior information and decision support systems and extensive staff training to develop attitudes and behavior consistent with the more collegial matrix organization culture. Further improvement in understanding the suitability of matrix organization for managing health care delivery organizations will involve appreciating the impact of partial implementation of matrix organization, temporary versus permanent uses of matrix organization, and the impact of the ambiguity created by dual lines of authority upon the exercise of power and authority.

Communication↗
PubMed1999

[Differential tyrosine phosphorylation of paxillin in human corneal epithelial cells on extracellular matrix proteins].

PURPOSE: To understand the interaction of corneal epithelial cells with laminin, fibronectin, and collagen type IV, major components of basement membrane, we investigated whether tyrosine phosphorylation of paxillin was increased during attachment of these cells to matrix proteins. Paxillin is one of the focal adhesion proteins and it is tyrosine phosphorylated during cell adhesion. METHODS: SV 40-transformed human corneal epithelial (HCE) cells were plated on these extracellular matrix proteins and incubated. The cellular lysates were submitted to immunoprecipitation and western blotting to determine tyrosine phosphorylation of paxillin. RESULTS: When the cells were plated on laminin matrix, the stained band indicating tyrosine phosphorylated paxillin increased in proportion to cultivation periods. The increase was significant at 6 to 24 hours of cultivation. When HCE cells were cultured on various concentrations of laminin, paxillin was up-regulated in phosphorylation in a dose-dependent fashion. On a fibronectin matrix, tyrosine phosphorylation of paxillin increased in a time-dependent fashion and peak time point was 6 hours of cultivation. Paxillin was up-regulated in tyrosine phosphorylation in direct relation with the fibronectin concentration. On a type IV collagen matrix, tyrosine phosphorylation of paxillin increased in relation to time, but not so rapidly as cultures on a laminin or fibronectin matrix. CONCLUSION: Differential tyrosine phosphorylation of paxillin may have been caused by different extracellular matrix proteins.

Cells, Cultured↗
PubMedDate not supplied

Bcl-2 and Bax proteins are nuclear matrix associated proteins.

Bcl-2 and Bax proteins are implicated in the regulation of apoptosis. Nuclear matrix has been demonstrated to be associated with a vast array of functional and regulatory properties of cells. NuMA is one member of a class of nuclear matrix proteins that resides in both the nucleus and mitotic apparatus. The nuclear lamins appear to form a thin fibrous structure immediately underlying the inner nuclear membrane of eukaryotic cell nuclei. The association of bcl-2 and Bax protein with nuclear matrix in glioblastoma cell line U343 was studied by confocal microscopy and Western blotting. Confocal microscopic images display that bcl-2 was localized at the peripheral of the nuclear matrix and Bax protein was located in the nuclear matrix. Western blotting detected a 26 kDa bcl-2 band and a specific band of Bax at around 66 kDa in nuclear matrix proteins. Our results suggest that bcl-2 and Bax proteins are nuclear matrix associated proteins.

Antigens, Nuclear↗
PubMed2001

Volumetric analysis of the germinal matrix and lateral ventricles performed using MR images of postmortem fetuses.

BACKGROUND AND PURPOSE: The volumetric changes of the ventricular system and germinal matrix are important to understand brain maturation and the mechanism of subependymal hemorrhage. Our purpose was to show the 3D configuration of the brain, germinal matrix, and lateral ventricles and to discuss the volumetric changes of each structure with maturation by using high-resolution MR imaging. METHODS: Three-dimensional MR images of 13 formalin-fixed fetal brains ranging from 7 to 28 weeks' gestational age (GA) were obtained on a 4.7-T unit. Each 3D configuration of the brain surface, germinal matrix, and ventricles was rendered from the cross-sectional imaging data sets and its volume measured. RESULTS: The germinal matrix was detected on MR images at 9 weeks' GA. Its volume exponentially increased by 23 weeks' GA (maximum, 2346 mm3) and then sharply decreased at 28 weeks' GA. The volume of the lateral ventricles increased gradually and reached 2646 mm3 peak volume at 23 weeks' GA. Between 11 and 23 weeks' GA, total brain and germinal matrix volumes were exponentially increasing, but the volume ratio of germinal matrix to brain was stable at about 5%. On the other hand, the volume ratio of lateral ventricles to brain was large between 10 and 13 weeks' GA. This period corresponded to the lateral ventricle showing a "vesicular" aspect with a thin mantle, and the developing mantle thickness of the hemisphere resulted in the decreasing ratio. CONCLUSION: Volumetric information concerning the germinal matrix and lateral ventricles may be useful in the accurate interpretation of clinical echograms and MR images of the fetal brain in utero.

Brain↗
PubMedDate not supplied

Comparative analysis of duodenal biopsy tissue orientation supported on vegetable matrix versus filter paper.

BACKGROUND: Biopsy tissue may get disoriented if filter paper is used as a supporting medium. Use of vegetable matrix (cucumber) as a supporting medium may obviate the need of lifting the tissue while making blocks and thus avoid disorientation that occurs during this step. OBJECTIVE: To compare the orientation of duodenal biopsy tissue supported on vegetable matrix (cucumber) and on filter paper. METHODS: Over one year, 40 patients (20 with large-volume diarrhea, 20 with dyspepsia) were included in the study. Two pairs of duodenal biopsy tissues were obtained during gastroscopy; one pair was placed on filter paper, the other on vegetable matrix. Tissue and vegetable matrix were embedded together while making blocks, whereas the tissue had to be lifted off in case of filter paper. Sections were stained and assessed for crypt-villous alignment, parallel orientation of crypts and presence of visible muscularis mucosae with the help of a scoring system. RESULTS: Compared to biopsy tissue supported on filter paper, vegetable matrix-supported tissues were better oriented. Scores were rated as bad, good and very good in 8, 11 and 21 vegetable matrix-mounted tissues and in 21, 11 and 8 filter paper-mounted tissues, respectively. CONCLUSION: Duodenal biopsy tissue supported on vegetable matrix (cucumber) is better oriented than that on filter paper.

Adolescent↗
PubMed2002

Autologous satellite cell seeding improves in vivo biocompatibility of homologous muscle acellular matrix implants.

Acellular matrix obtained from homologous muscular tissue has been previously used to repair muscular defects. However, the implants, although not rejected, give rise to an intense inflammatory response and are rapidly replaced by fibrous tissue. In this study we examined the possibility that co-culture with autologous satellite cells can improve the efficiency of homologous acellular matrix as skeletal muscle substitute. Satellite cells, isolated from rat dorsal muscle, were cultured in vitro on homologous acellular matrix obtained by detergent-enzymatic treatment of abdominal muscle fragments. Scanning electron microscopy revealed that after 24 h of co-culture satellite cells were attached to the matrix, but still possessed a round shape. After 96 h, seeded cells began to flatten and to differentiate, originating few multinucleated myotubes. Patches of homologous matrix, seeded or not with autologous satellite cells, were implanted in the dorsal muscle of rats. At autopsy, the implants were recovered and processed for light microscopy. Two weeks after surgery, fibrous tissue started to replace the grafts composed only by acellular matrix, which at the 4th week were transformed into a fibrous scar. In contrast, at both times post-surgery the structure of implants containing autologous satellite cells was well preserved. The inflammatory reaction was modest and fibrosis was confined to the periphery of the grafts. It is concluded that the presence of autologous satellite cells is an important factor to preserve the structural integrity and to improve in vivo biocompatibility of homologous muscular acellular matrix implants.

Animals↗
PubMed2003

Soft tissue ridge augmentation with an acellular dermal matrix.

The goal of this case report was to evaluate the use of an acellular dermal matrix for soft tissue ridge augmentation. The technique used was a modification of the procedure proposed by Langer and Calagna and involved reflecting a partial-thickness pedicle, placing an acellular dermal matrix, and covering the acellular dermal matrix with the pedicle. The increases in the quantity of tissue obtained were adequate to permit placing an esthetic fixed restoration in four of the five cases treated. In one of the five cases, the acellular dermal matrix became exposed and partially sloughed. This resulted in less of an increase in tissue than in the other cases. Histologic evaluation of this case showed that the entire acellular dermal matrix did not slough; part of the acellular dermal matrix was incorporated into the result. The use of an acellular dermal matrix for soft tissue ridge augmentation is a clinically valuable technique.

Adult↗
PubMed2003

The use of the matrix method for the study of human motion: theory and applications.

Kinematics has been successfully used to describe body motion without reference to the kinetics (or forces causing the motion). In this article, both the theory and applications of the matrix method are provided to describe complex human motion. After the definition of a Cartesian coordinate frame is introduced, the description of transformations between multiple coordinate frames is given; the decomposition of a transformation matrix into anatomical joint motion parameters (e.g. Euler angles) is then explained. The advantages of the matrix method are illustrated by three examples related to biomechanical studies. The first describes a reaching and grasping task in which matrix transformations are applied to position the hand with respect to an object during grasping. The second example demonstrates the utility of the matrix method in revealing the coupling motion of the wrist between flexion-extension and radial-ulnar deviation. The last example highlights the indispensable use of the matrix method for the study of knee biomechanics, including the description of knee joint kinematics during functional activities and determination of in-situ ligament forces using robotic technology, which has advanced our understanding of the functions of the cruciate ligaments to knee joint kinematics. It is hoped that the theoretical development and biomechanical application examples will help the readers apply the matrix method to research problems related to human motion.

Biomechanical Phenomena↗
PubMed2005

Relationship of chondrocyte apoptosis to matrix degradation and swelling potential of osteoarthritic cartilage.

BACKGROUND AND PURPOSE: Softening of cartilage is the initial degenerative step of osteoarthritic cartilage by matrix degradation and corruption of interconnection of the collagen fibrillar network. The purpose of this study was to investigate the correlation of chondrocyte apoptosis, matrix degradation, and the corruption of collagen architecture in the development of severe swelling of osteoarthritic cartilage. METHODS: Twenty osteoarthritic and 7 normal femoral neck fractured cartilage samples were obtained from patients with knee osteoarthritis and normal patients with femoral neck fracture at the time of total hip joint replacement surgery. Apoptosis was verified by TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end-labeling) staining and structural changes were observed under phase-contrast microscopy. Matrix degradation was evaluated by histochemical analysis of proteoglycans. Swelling tests were performed by immersing the cartilage slices in hypotonic solution. The results of ultrastructural study of collagen architecture of osteoarthritic cartilage performed by scanning electron microscopy before and after swelling were compared. RESULTS: Matrix degradation was most prominent in the middle zone of osteoarthritic cartilage. The percentage of chondrocytes in osteoarthritic cartilage showing apoptosis ranged from 15 to 20% (average, 18%; standard deviation (SD) = 3.2%) and was correlated with the extent of structural changes and matrix degradation. The swelling strain of the osteoarthritic cartilage varied from 120 to 200% (average, 160%; SD = 40%) depending on the degree of matrix degradation and structural changes. The loss of interconnectivity of collagen fibrillar architecture was correlated with the increased swelling potential of osteoarthritic cartilage. CONCLUSION: This study demonstrated that chondrocyte apoptosis was correlated with matrix degradation and the corruption of fibrillar architecture and that the extent of these manifestations correlated with the swelling potential of osteoarthritic cartilage. These findings also emphasize the importance of the fibrillar architecture in maintaining the mechanical properties of cartilage.

Aged↗
PubMed2004

Hydroxyapatite/tricalcium phosphate matrix scaffold as cell carriers in vitro.

OBJECTIVE: To explore the possibility of hydroxyapatite/tricalcium phosphate (HA/TCP) matrix scaffold as cell carriers in tissue engineering, and to provide a direct evidence for the resurfacing of matrix scaffold. METHODS: Human bone marrow stromal cells (hBMSCs) and umbilical vein endothelial cells (UVECs) were co-cultured on the surface of matrix scaffold. The morphologic characters during culture on HA/TCP matrix scaffold's surfaces were checked by light microscope, fluorescence microscope, and scanning electronic microscope. RESULTS: Both human bone marrow stromal cells and human umbilical vein endothelial cells showed good biocompatibility with HA/TCP matrix scaffold. The cell growth into the micropore of HA/TCP matrix scaffold could be seen under both fluorescence microscopy and scaning electron microscopy. CONCLUSION: HA/TCP matrix scaffold can be used as a vehicle for the cell transplantation.

Biocompatible Materials↗