Radiation effects on the matrix synthesis in non-ossifying embryonic cartilage in vitro: A functional and morphological study

Background/Aims: An adequate matrix production of nucleus pulposus (NP) cells is an important tissue engineering-based strategy to regenerate degenerative discs. Here, we mainly aimed to investigate the effects and mechanism of mechanical compression (i.e., static compression vs. dynamic compression) on the matrix synthesis of three-dimensional (3D) cultured NP cells in vitro. Methods: Rat NP cells seeded on small intestinal submucosa (SIS) cryogel scaffolds were cultured in the chambers of a self-developed, mechanically active bioreactor for 10 days. Meanwhile, the NP cells were subjected to compression (static compression or dynamic compression at a 10% scaffold deformation) for 6 hours once per day. Unloaded NP cells were used as controls. The cellular phenotype and matrix biosynthesis of NP cells were investigated by real-time PCR and Western blotting assays. Lentivirus-mediated N-cadherin (N-CDH) knockdown and an inhibitor, LY294002, were used to further investigate the role of N-CDH and the PI3K/Akt pathway in this process. Results: Dynamic compression better maintained the expression of cell-specific markers (keratin-19, FOXF1 and PAX1) and matrix macromolecules (aggrecan and collagen II), as well as N-CDH expression and the activity of the PI3K/Akt pathway, in the 3D-cultured NP cells compared with those expression levels and activity in the cells grown under static compression. Further analysis showed that the N-CDH knockdown significantly down-regulated the expression of NP cell-specific markers and matrix macromolecules and inhibited the activation of the PI3K/Akt pathway under dynamic compression. However, inhibition of the PI3K/Akt pathway had no effects on N-CDH expression but down-regulated the expression of NP cell-specific markers and matrix macromolecules under dynamic compression. Conclusion: Dynamic compression increases the matrix synthesis of 3D-cultured NP cells compared with that of the cells under static compression, and the N-CDH-PI3K/Akt pathway is involved in this regulatory process. This study provides a promising strategy to promote the matrix deposition of tissue-engineered NP tissue in vitro prior to clinical transplantation.

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Radiolabeled r-Hirudin as a Measure of Thrombin Activity at, or within, the Rabbit Aorta Wall In Vitro and In Vivo

Thrombosis and Haemostasis ◽

10.1055/s-0038-1642467 ◽

1994 ◽

Vol 71 (04) ◽

pp. 499-506 ◽

Cited By ~ 10

Author(s):

Mark W C Hatton ◽

Bonnie Ross-Ouellet

Keyword(s):

Rabbit Aorta ◽

Balloon Injury ◽

Recombinant Hirudin ◽

Aorta Wall ◽

Thrombin Activity ◽

Before And After ◽

The Matrix

SummaryThe behavior of 125I-labeled recombinant hirudin towards the uninjured and de-endothelialized rabbit aorta wall has been studied in vitro and in vivo to determine its usefulness as an indicator of thrombin activity associated with the aorta wall. Thrombin adsorbed to either sulfopropyl-Sephadex or heparin-Sepharose bound >95% of 125I-r-hirudin and the complex remained bound to the matrix. Binding of 125I-r-hirudin to the exposed aorta subendothelium (intima-media) in vitro was increased substantially if the tissue was pre-treated with thrombin; the quantity of l25I-r-hirudin bound to the de-endothelialized intima-media (i.e. balloon-injured in vitro) correlated positively with the quantity of bound 131I-thrombin (p <0.01). Aortas balloon-injured in vivo were measured for thrombin release from, and binding of 125I-r-hirudin to, the de-endothelialized intimal surface in vitro; 125I-r-hirudin binding correlated with the amount of active thrombin released (p <0.001). Uptake of 125I-r-hirudin by the aorta wall in vivo was proportional to the uptake of 131I-fibrinogen (as an indicator of thrombin activity) before and after balloon injury. After 30 min in the circulation, specific 125I-r-hirudin binding to the uninjured and de-endo- thelialized (at 1.5 h after injury) aorta wall was equivalent to 3.4 (± 2.5) and 25.6 (±18.1) fmol of thrombin/cm2 of intima-media, respectively. Possibly, only hirudin-accessible, glycosaminoglycan-bound thrombin is measured in this way.

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Formulation and Evaluation of Galantamine Hydrobromide Floating Matrix Tablet

International Journal of Drug Delivery Technology ◽

10.25258/ijddt.v8i2.13868 ◽

2018 ◽

Vol 8 (2) ◽

Author(s):

Poreddy Srikanth Reddy ◽

Penjuri Subhash Chandra Bose ◽

Vuppula Sruthi ◽

Damineni Saritha

Keyword(s):

Sodium Alginate ◽

Xanthan Gum ◽

Lag Time ◽

Matrix Tablets ◽

In Vitro Dissolution ◽

Matrix Tablet ◽

Compression Technique ◽

Weight Variation ◽

The Matrix

The aim of the present work was to prepare floating tablets of galantamine HBr using sodium alginate and xanthan gum as matrix forming carriers. Galantamine HBr is used for the treatment of mild to moderate Alzheimer's disease and various other memory impairments, in particular those of vascular origin. The matrix tablet formulations were prepared by varying the concentrations of sodium alginate and xanthan gum. The tablets were prepared by direct compression technique using PVP K-30 as a binder and sodium bicarbonate for development of CO2. The prepared matrix tablets were evaluated for properties such as hardness, thickness, friability, weight variation, floating lag time, compatibility using DSC and FTIR. In vitro dissolution was carried out for 12 hrs in 0.1N HCl at 37±0.5 ºC using USP paddle type dissolution apparatus. It was noted that, all the prepared formulations had desired floating lag time and constantly floated on dissolution medium by maintaining the matrix integrity. The drug release from prepared tablets was found to vary with varying concentration of the polymers, sodium alginate and xanthan gum. From the study it was concluded that floating drug delivery system for galantamine HBr can be prepared by using sodium alginate and xanthan gum as a carrier.

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BMP2 Is Required for Postnatal Maintenance of Osteochondral Tissues of the Temporomandibular Joint

Cartilage ◽

10.1177/1947603520980158 ◽

2020 ◽

pp. 194760352098015

Author(s):

Mara H. O’Brien ◽

Eliane H. Dutra ◽

Shivam Mehta ◽

Po-Jung Chen ◽

Sumit Yadav

Keyword(s):

Age Groups ◽

Mandibular Condyle ◽

Bone Morphogenetic Protein 2 ◽

Matrix Synthesis ◽

Cartilage Growth ◽

Chondrocyte Proliferation ◽

Conditional Deletion ◽

Morphogenetic Protein

Objective Bone morphogenetic protein 2 (BMP2) plays important roles in cartilage growth and development. Paradoxically, elevated levels of BMP2 leads to hypertrophic differentiation and osteoarthritis of cartilage. We examined the in vivo loss of BMP2 in cells expressing aggrecan of the mandibular condyle and knee. Design Three-week-old BMP2 flox/flox- CreER-positive mice and their Cre-negative littermates were treated with tamoxifen and raised until 3 or 6 months. We also investigated the direct effects of BMP2 on chondrocytes in vitro. Cells from the mandibular condyle of mice were treated with recombinant human BMP2 (rhBMP2) or rhNoggin (inhibitor of BMP2 signaling). Results Conditional deletion of BMP2 caused breakage of the cartilage integrity in the mandibular condyle of mice from both age groups, accompanied by a decrease in cartilage thickness, matrix synthesis, mineralization, chondrocyte proliferation, and increased expression of degeneration markers, while the effects at articular cartilage were not significant. In vitro results revealed that rhBMP2 increased chondrocyte proliferation, mineralization, and differentiation, while noggin induced opposite effects. Conclusions In conclusion, BMP2 is essential for postnatal maintenance of the osteochondral tissues of the mandibular condyle.

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Formulation and evaluation of bi-layer floating tablets of ziprasidone HCl and trihexyphenidyl HCl

Brazilian Journal of Pharmaceutical Sciences ◽

10.1590/s1984-82502011000300012 ◽

2011 ◽

Vol 47 (3) ◽

pp. 545-553 ◽

Cited By ~ 2

Author(s):

Sathis Kumar Dinakaran ◽

Santhos Kumar ◽

David Banji ◽

Harani Avasarala ◽

Venkateshwar Rao

Keyword(s):

Sustained Release ◽

In Vitro Release ◽

Chemical Properties ◽

Matrix Tablets ◽

In Vitro Dissolution ◽

Floating Tablets ◽

Ir Studies ◽

Weight Variation ◽

The Matrix

The purpose of this research study was to establish ziprasidone HCl NR 40 mg and trihexyphenidyl HCl SR 4mg in the form of bi-layer sustained release floating tablets. The tablets were prepared using sodium HPMC K4M / HPMC K15M as bio-adhesive polymers and sodium bicarbonate acting as a floating layer. Tablets were evaluated based on different parameters such as thickness, hardness, friability, weight variation, in vitro dissolution studies, content of active ingredient and IR studies. The physico-chemical properties of the finished product complied with the specifications. In vitro release from the formulation was studied as per the USP XXIII dissolution procedure. The formulations gave a normal release effect followed by sustained release for 12 h which indicates bimodal release of ziprasidone HCl from the matrix tablets. The data obtained was fitted to Peppas models. Analysis of n values of the Korsmeyer equation indicated that the drug release involved non-diffusional mechanisms. By the present study, it can be concluded that bi-layer tablets of ziprasidone HCl and trihexyphenidyl HCl will be a useful strategy for extending the metabolism and improving the bioavailability of Ziprasidone HCl and Trihexyphenidyl HCl.

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Transplantation of mesenchymal stromal cells on mineralized collagen leads to ectopic matrix synthesis in vivo independently from prior in vitro differentiation

Cytotherapy ◽

10.1080/14653240600845187 ◽

2006 ◽

Vol 8 (4) ◽

pp. 354-366 ◽

Cited By ~ 18

Author(s):

P. Niemeyer ◽

P. Kasten ◽

H.-G. Simank ◽

J. Fellenberg ◽

A. Seckinger ◽

...

Keyword(s):

Mesenchymal Stromal Cells ◽

Stromal Cells ◽

In Vitro Differentiation ◽

Matrix Synthesis ◽

Mineralized Collagen

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Microwave Radiation Effects on Cardiac Muscle Cells in Vitro

Radiation Research ◽

10.2307/3575511 ◽

1981 ◽

Vol 86 (2) ◽

pp. 358 ◽

Cited By ~ 17

Author(s):

M. J. Galvin ◽

C. A. Hall ◽

D. I. McRee

Keyword(s):

Cardiac Muscle ◽

Microwave Radiation ◽

Radiation Effects ◽

Muscle Cells ◽

Cardiac Muscle Cells

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The influence of different geometries of matrix/scaffold on the remodeling process of a bone and bioresorbable material mixture with voids

Mathematics and Mechanics of Solids ◽

10.1177/1081286515616052 ◽

2015 ◽

Vol 22 (5) ◽

pp. 969-987 ◽

Cited By ~ 27

Author(s):

Ivan Giorgio ◽

Ugo Andreaus ◽

Tomasz Lekszycki ◽

Alessandro Della Corte

Keyword(s):

Bone Growth ◽

Matrix Material ◽

Porous Solids ◽

Artificial Material ◽

Matrix Deposition ◽

Aspect Ratios ◽

Adopted Model ◽

The Matrix ◽

Bioresorbable Material

Since internal architecture greatly influences crucial factors for tissue regeneration, such as nutrient diffusion, cell adhesion and matrix deposition, scaffolds have to be carefully designed, keeping in mind case-specific mechanical, mass transport and biological requirements. However, customizing scaffold architecture to better suit conflicting requirements, such as biological and mechanical ones, remains a challenging issue. Recent advances in printing technologies, together with the synthesis of novel composite biomaterials, have enabled the fabrication of various scaffolds with defined shape and controlled in vitro behavior. Thus, the influence of different geometries of the assemblage of the matrix and scaffold on the remodeling processes of living bone and artificial material should be investigated. To this end, two implant shapes are considered in this paper, namely a circular inclusion and a rectangular groove of different aspect ratios. A model of a mixture of bone tissue and bioresorbable material with voids was used to numerically analyze the physiological balance between the processes of bone growth and resorption and artificial material resorption in a plate-like sample. The adopted model was derived from a theory for the behavior of porous solids in which the matrix material is elastic and the interstices are void of material.

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In vitro Release Kinetics Study of Ranolazine from Swellable Hydrophilic Matrix Tablets

Dhaka University Journal of Pharmaceutical Sciences ◽

10.3329/dujps.v8i1.5333 ◽

1970 ◽

Vol 8 (1) ◽

pp. 31-38 ◽

Cited By ~ 1

Author(s):

Mohammad Nezab Uddin ◽

Ishtiaq Ahmed ◽

Monzurul Amin Roni ◽

Muhammad Rashedul Islam ◽

Mohammad Habibur Rahman ◽

...

Keyword(s):

Drug Release ◽

Sustained Release ◽

Release Kinetics ◽

In Vitro Release ◽

High Viscosity ◽

Matrix Tablets ◽

Release Studies ◽

The Matrix ◽

Vitro Release

The objective of this study was to design oral sustained release matrix tablets of Ranolazine usinghydroxypropyl methylcellulose (HPMC) as the retardant polymer and to study the effect of formulation factors suchas polymer proportion and polymer viscosity on the release of drug. In vitro release studies were performed usingUSP type II apparatus (paddle method) in 900 mL of 0.1N HCl at 100 rpm for 12 hours. The release kinetics wasanalyzed using the zero-order, first order, Higuchi and Korsmeyer-Peppas equations to explore and explain themechanism of drug release from the matrix tablets. In vitro release studies revealed that the release rate decreasedwith increase in polymer proportion and viscosity grade. Mathematical analysis of the release kinetics indicated thatthe nature of drug release from the matrix tablets was dependent on drug diffusion and polymer relaxation andtherefore followed non-Fickian or anomalous release. The developed controlled release matrix tablets of Ranolazineprepared with high viscosity HPMC extended release up to 12 hours.Key words: Ranolazine; Sustained release; Methocel E50 Premium LV; Methocel K100LV CR; Methocel K4M CR;Methocel K15M CR.DOI: 10.3329/dujps.v8i1.5333Dhaka Univ. J. Pharm. Sci. 8(1): 31-38, 2009 (June)

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