MyMedR

Comparison of chitosan scaffold and chitosan-collagen scaffold: a preliminary study

Norazril SA, Aminuddin BS, Norhayati MM, Mazlyzam AL, Fauziah O, Ruszymah BH

Med J Malaysia, 2004 May;59 Suppl B:186-7.

Chitosan has similar structure to glycosaminoglycans in the tissue, thus may be a good candidates as tissue engineering scaffold. However, to improve their cell attachment ability, we try to incorporate this natural polymer with collagen by combining it via cross-linking process. In this preliminary study we evaluate the cell attachment ability of chitosan-collagen scaffold versus chitosan scaffold alone. Chitosan and collagen were dissolved in 1% acetic acid and then were frozen for 24 hours before the lyophilizing process. Human skin fibroblasts were seeded into both scaffold and were cultured in F12: DMEM (1:1). Metabolic activity assay were used to evaluate cell attachment ability of scaffold for a period of 1, 3, 7 and 14 days. Scanning electron micrographs shows good cell morphology on chitosan-collagen hybrid scaffold. In conclusion, the incorporation of collagen to chitosan will enhance its cell attachment ability and will be a potential scaffold in tissue engineering.

Matched MeSH terms: Organ Culture Techniques/methods*

Evaluation of suitable biodegradable scaffolds for engineered bone tissue

Phang MY, Ng MH, Tan KK, Aminuddin BS, Ruszymah BH, Fauziah O

Med J Malaysia, 2004 May;59 Suppl B:198-9.

PMID: 15468886

Tricalcium phosphate/hydroxyapatite (TCP/HA), hydroxyapatite (HA), chitosan and calcium sulphate (CaSO4) were studied and evaluated for possible bone tissue engineered construct acting as good support for osteogenic cells to proliferate, differentiate, and eventually spread and integrate into the scaffold. Surface morphology visualized by SEM showed that scaffold materials with additional fibrin had more cell densities attached than those without, depicting that the presence of fibrin and collagen fibers were truly a favourite choice of cells to attach. In comparison of various biomaterials used incorporated with fibrin, TCP/HA had the most cluster of cells attached.

Matched MeSH terms: Organ Culture Techniques/methods*

Collagen as potential cell scaffolds for tissue engineering

Annuar N, Spier RE

Med J Malaysia, 2004 May;59 Suppl B:204-5.

PMID: 15468889

Selections of collagen available commercially were tested for their biocompatibility as scaffold to promote cell growth in vitro via simple collagen fast test and cultivation of mammalian cells on the selected type of collagen. It was found that collagen type C9791 promotes the highest degree of aggregation as well as cells growth. This preliminary study also indicated potential use of collagen as scaffold in engineered tissue.

Matched MeSH terms: Organ Culture Techniques/methods

Coral--polyhydroxybutrate composite scaffold for tissue engineering: prefabrication properties

Al-Salihi KA, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:202-3.

PMID: 15468888

In this study the surface properties of two particulate coral and polyhydroxybutrate (PHB) were studied in order to characterize them prior to use in composite production. Coral powder and PHB particle were evaluated using scanning electron microscopy and confocal laser scanning microscopy, to measure surface porosity and pores size. The results showed that coral powder has multiple pleomorphic micropores cross each others give appearance of micro-interconnectivity. Some pore reached to 18 microm with an average porosity of 70%. PHB revealed multiple different size pores extended to the depth, with an average some times reach 25 microm and porosity 45%. These findings demonstrate that both coral and PHB have excellent pores size and porosity that facilitate bone in growth, vascular invasion and bone development. We believe that incorporation of coral powder into PHB will make an excellent composite scaffold for tissue engineering.

Matched MeSH terms: Organ Culture Techniques/methods

Tissue-engineered bone via seeding bone marrow stem cell derived osteoblasts into coral: a rat model

Al-Salihi KA

Med J Malaysia, 2004 May;59 Suppl B:200-1.

PMID: 15468887

In the present study, natural coral of porites species was used as scaffold combined with in vitro expanded bone marrow stem cell derived osteoblasts (BMSC-DO), to develop a tissue-engineered bone graft in a rat model. Coral was molded into the shape of rat mandible seeded with 5x10(6) /ml BMSC-DO subsequently implanted subcutaneously in the back of 5 week Sprague dawely rats for 3 months. Coral alone was implanted as a control. The implants were harvest and processed for gross inspection and histological observations. The results showed that newly bone grafts were successfully formed coral seeded with cells group showed smooth highly vascularized like bone tissue. Histological sections revealed mature bone formation and lots of blood vessel, the bone formation occurred in the manner resemble intramembraneous bone formation. This study demonstrates that coral can be use as a suitable scaffold material for delivering bone marrow mesenchymal stem cells in tissue engineering.

Matched MeSH terms: Organ Culture Techniques/methods*

Design and fabrication of scaffolds for anatomic bone reconstruction

Hollister SJ, Lin CY, Lin CY, Schek RD, Taboas JM, Flanagan CL, et al.

Med J Malaysia, 2004 May;59 Suppl B:131-2.

PMID: 15468853

Matched MeSH terms: Organ Culture Techniques/methods*

The fundamentals of tissue engineering: new scaffolds

Di Silvio L, Gurav N, Sambrook R

Med J Malaysia, 2004 May;59 Suppl B:89-90.

PMID: 15468832

The ability to regenerate new bone for skeletal use is a major clinical need. In this study, two novel porous calcium phosphate materials pure HA and biphasic HA/beta-Tricalcium phosphate (HA/beta -TCP) were evaluated as potential scaffolds for cell-seeded bone substitutes using human osteoblast-like cells (HOS) and primary human mesenchymal stem cells (hMSCs). A high rate of proliferation was observed on both scaffolds. A greater increase in alkaline phosphatase (ALP- an indicator of osteoblast differentiation) was observed on HA/beta -TCP compared to HA. This observation indicates that HA/TCP may play a role in inducing osteoblastic differentiation. Although further evaluation is required both materials show potential as innovative synthetic substitutes for tissue engineered scaffolds.

Matched MeSH terms: Organ Culture Techniques/standards*

Bone marrow mesenchymal stem cells differentiation and proliferation on the surface of coral implant

Al-Salihi KA, Samsudin AR

Med J Malaysia, 2004 May;59 Suppl B:45-6.

PMID: 15468811

This study was designed to evaluate the ability of natural coral implant to provide an environment for marrow cells to differentiate into osteoblasts and function suitable for mineralized tissue formation. DNA content, alkaline phosptatase (ALP) activity, calcium (Ca) content and mineralized nodules, were measured at day 3, day 7 and day 14, in rat bone marrow stromal cells cultured with coral discs glass discs, while cells alone and coral disc alone were cultured as control. DNA content, ALP activity, Ca content measurements showed no difference between coral, glass and cells groups at 3 day which were higher than control (coral disc alone), but there were higher measurement at day 7 and 14 in the cell cultured on coral than on glass discs, control cells and control coral discs. Mineralized nodules formation (both in area and number) was more predominant on the coral surface than in control groups. These results showed that natural coral implant provided excellent and favorable situation for marrow cell to differentiate to osteoblasts, lead to large amount of mineralized tissue formation on coral surface. This in vitro result could explain the rapid bone bonding of coral in vivo.

Matched MeSH terms: Organ Culture Techniques*

Strategy for generating tissue-engineered human bone construct

Tan KK, Aminuddin BS, Tan GH, Sabarul Afian M, Ng MH, Fauziah O, et al.

Med J Malaysia, 2004 May;59 Suppl B:43-4.

PMID: 15468810

The strategy used to generate tissue-engineered bone construct, in view of future clinical application is presented here. Osteoprogenitor cells from periosteum of consenting scoliosis patients were isolated. Growth factors viz TGF-B2, bFGF and IGF-1 were used in concert to increase cell proliferation during in vitro cell expansion. Porous tricalcium phosphate (TCP)-hydroxyapatite (HA) scaffold was used as the scaffold to form 3D bone construct. We found that the addition of growth factors, greatly increased cell growth by 2 to 7 fold. TCP/HA proved to be the ideal scaffold for cell attachment and proliferation. Hence, this model will be further carried out on animal trial.

Matched MeSH terms: Organ Culture Techniques

Scaffolds in bone tissue engineering

Nather A

Med J Malaysia, 2004 May;59 Suppl B:37-8.

PMID: 15468807

Matched MeSH terms: Organ Culture Techniques/methods*

Towards engineering of a tracheal equivalent: identification of epithelial precursor cells, differentiation and cocultivation techniques

Rotter N, Stölzel K, Endres M, Leinhase I, Ziegelaar BW, Sittinger M

Med J Malaysia, 2004 May;59 Suppl B:35-6.

PMID: 15468806

Matched MeSH terms: Organ Culture Techniques

Tissue engineered trachea using sheep nasal septum

Kojima K

Med J Malaysia, 2004 May;59 Suppl B:32-3.

PMID: 15468805

Matched MeSH terms: Organ Culture Techniques

Autologous human fibrin as the biomaterial for tissue engineering

Ruszymah BH

Med J Malaysia, 2004 May;59 Suppl B:30-1.

PMID: 15468804

Patient own fibrin may act as the safest, cheapest and immediate available biodegradable scaffold material in clinical 1 tissue engineering. This study investigated the feasibility of using patient own fibrin isolated from whole blood to construct a new human cartilage, skin and bone. Constructed in vitro tissues were implanted on the dorsal part of the nude mice for in vivo maturation. After 8 weeks of implantation, the engineered tissues were removed for histological analysis. Our results demonstrated autologous fibrin has great potential as clinical scaffold material to construct various human tissues.

Matched MeSH terms: Organ Culture Techniques

Quercetin, a flavonoid antioxidant, modulates endothelium-derived nitric oxide bioavailability in diabetic rat aortas

Machha A, Achike FI, Mustafa AM, Mustafa MR

Nitric Oxide, 2007 Jun;16(4):442-7.

PMID: 17513143 DOI: 10.1016/j.niox.2007.04.001

The present work examined the effect of chronic oral administration of quercetin, a flavonoid antioxidant, on blood glucose, vascular function and oxidative stress in STZ-induced diabetic rats. Male Wistar-Kyoto (WKY) rats were randomized into euglycemic, untreated diabetic, vehicle (1% w/v methylcellulose)-treated diabetic, which served as control, or quercetin (10mgkg(-1) body weight)-treated diabetic groups and treated orally for 6 weeks. Quercetin treatment reduced blood glucose level in diabetic rats. Impaired relaxations to endothelium-dependent vasodilator acetylcholine (ACh) and enhanced vasoconstriction responses to alpha(1)-adrenoceptor agonist phenylephrine (PE) in diabetic rat aortic rings were restored to euglycemic levels by quercetin treatment. Pretreatment with N(omega)-nitro-l-arginine methyl ester (l-NAME, 10microM) or methylene blue (10microM) completely blocked but indomethacin (10microM) did not affect relaxations to ACh in aortic rings from vehicle- or quercetin-treated diabetic rats. PE-induced vasoconstriction with an essentially similar magnitude in vehicle- or quercetin-treated diabetic rat aortic rings pretreated with l-NAME (10microM) plus indomethacin (10microM). Quercetin treatment reduced plasma malonaldehyde (MDA) plus 4-hydroxyalkenals (4-HNE) content as well as increased superoxide dismutase activity and total antioxidant capacity in diabetic rats. From the present study, it can be concluded that quercetin administration to diabetic rats restores vascular function, probably through enhancement in the bioavailability of endothelium-derived nitric oxide coupled to reduced blood glucose level and oxidative stress.

Matched MeSH terms: Organ Culture Techniques

Bisnicalaterines B and C, atropisomeric bisindole alkaloids from Hunteria zeylanica, showing vasorelaxant activity

Hirasawa Y, Hara M, Nugroho AE, Sugai M, Zaima K, Kawahara N, et al.

J Org Chem, 2010 Jun 18;75(12):4218-23.

PMID: 20469917 DOI: 10.1021/jo1006762

Two new bisindole alkaloids, bisnicalaterines B and C (1 and 2) consisting of an eburnane and a corynanthe type of skeletons, were isolated from the bark of Hunteria zeylanica. Their absolute structures were determined by combination of NMR, CD, and computational methods, and each of them was shown to be in an atropisomeric relationship. Bisnicalaterines B and C (1 and 2) showed potent vasorelaxant activity on isolated rat aorta.

Matched MeSH terms: Organ Culture Techniques

An ex vivo culture model for orthodontically induced root resorption

Wan Hassan WN, Stephenson PA, Waddington RJ, Sloan AJ

J Dent, 2012 May;40(5):406-15.

PMID: 22342686 DOI: 10.1016/j.jdent.2012.02.002

Root resorption is a ubiquitous although undesirable sequela to orthodontic treatment. Current methods to investigate the pathophysiology have certain limitations. In pursuit to understand and develop treatment modalities for orthodontically induced root resorption, the ability to manipulate cells within their natural extracellular matrix in a three dimensional organotypic model is invaluable. The study aimed to develop a laboratory-based organotypic model to investigate the effect of orthodontic forces on the periodontium.

Matched MeSH terms: Organ Culture Techniques

Vakhshiteh F, Allaudin ZN, Mohd Lila MA, Hani H

Xenotransplantation, 2013 02 14;20(2):82-8.

PMID: 23406308 DOI: 10.1111/xen.12023

BACKGROUND: The successful isolation, purification, and culture of caprine islets has recently been reported. The present study shows arange of size distribution in caprine islet diameter from 50 to 250 μm, in which 80% of the total islet yield was comprised of small islets.

METHODS: Caprine islets were isolated and purified. Islets were handpicked and the diameter of the islets was recorded using light microscopy. Viablility of the islets was analyzed by confocal microscopy. Insulin secretion assay was carried out and analyzed by ELISA.

RESULTS: When tested at 48 h after isolation, these small islets were 29.3% more viable compared to the large-sized islets. Large islets showed a high ratio (P

Matched MeSH terms: Organ Culture Techniques

Organotypic culture of human amnion cells in air-liquid interface as a potential substitute for skin regeneration

Fatimah SS, Chua K, Tan GC, Azmi TI, Tan AE, Abdul Rahman H

Cytotherapy, 2013 Aug;15(8):1030-41.

PMID: 23830235 DOI: 10.1016/j.jcyt.2013.05.003

The aim of the present study was to evaluate the effects of air-liquid interface on the differentiation potential of human amnion epithelial cells (HAECs) to skin-like substitute in organotypic culture.

Matched MeSH terms: Organ Culture Techniques

Fulltext Transcription factor CREB3L1 regulates vasopressin gene expression in the rat hypothalamus

Greenwood M, Bordieri L, Greenwood MP, Rosso Melo M, Colombari DS, Colombari E, et al.

J Neurosci, 2014 Mar 12;34(11):3810-20.

PMID: 24623760 DOI: 10.1523/JNEUROSCI.4343-13.2014

Arginine vasopressin (AVP) is a neurohypophysial hormone regulating hydromineral homeostasis. Here we show that the mRNA encoding cAMP responsive element-binding protein-3 like-1 (CREB3L1), a transcription factor of the CREB/activating transcription factor (ATF) family, increases in expression in parallel with AVP expression in supraoptic nuclei (SONs) and paraventicular nuclei (PVNs) of dehydrated (DH) and salt-loaded (SL) rats, compared with euhydrated (EH) controls. In EH animals, CREB3L1 protein is expressed in glial cells, but only at a low level in SON and PVN neurons, whereas robust upregulation in AVP neurons accompanied DH and SL rats. Concomitantly, CREB3L1 is activated by cleavage, with the N-terminal domain translocating from the Golgi, via the cytosol, to the nucleus. We also show that CREB3L1 mRNA levels correlate with AVP transcription level in SONs and PVNs following sodium depletion, and as a consequence of diurnal rhythm in the suprachiasmatic nucleus. We tested the hypothesis that CREB3L1 activates AVP gene transcription. Both full-length and constitutively active forms of CREB3L1 (CREB3L1CA) induce the expression of rat AVP promoter-luciferase reporter constructs, whereas a dominant-negative mutant reduces expression. Rat AVP promoter deletion constructs revealed that CRE-like and G-box sequences in the region between -170 and -120 bp are important for CREB3L1 actions. Direct binding of CREB3L1 to the AVP promoter was shown by chromatin immunoprecipitation both in vitro and in the SON itself. Injection of a lentiviral vector expressing CREB3L1CA into rat SONs and PVNs resulted in increased AVP biosynthesis. We thus identify CREB3L1 as a regulator of AVP transcription in the rat hypothalamus.

Matched MeSH terms: Organ Culture Techniques

Isolation and characterization of α-elapitoxin-Bf1b, a postsynaptic neurotoxin from Malaysian Bungarus fasciatus venom

Rusmili MR, Tee TY, Mustafa MR, Othman I, Hodgson WC

Biochem Pharmacol, 2014 Mar 15;88(2):229-36.

PMID: 24440452 DOI: 10.1016/j.bcp.2014.01.004

Bungarus fasciatus is one of three species of krait found in Malaysia. Envenoming by B. fasciatus results in neurotoxicity due to the presence of presynaptic and postsynaptic neurotoxins. Antivenom, either monovalent or polyvalent, is the treatment of choice in systemically envenomed patients. In this study, we have isolated a postsynaptic neurotoxin which we named α-elapitoxin-Bf1b. This toxin has an approximate molecular weight of 6.9 kDa, with LCMS/MS data showing that it is highly homologous with Neurotoxin 3FTx-RI, a toxin identified in the Bungarus fasciatus venom gland transcriptome. α-Elapitoxin-Bf1b also shared similarity with short-chain neurotoxins from Laticauda colubrina and Pseudechis australis. α-Elapitoxin-Bf1b produced concentration- and time-dependent neurotoxicity in the indirectly-stimulated chick biventer cervicis muscle preparation, an effect partially reversible by repetitive washing of the preparation. The pA2 value for α-elapitoxin-Bf1b of 9.17 ± 0.64, determined by examining the effects of the toxin on cumulative carbacol concentration-response curves, indicated that the toxin is more potent than tubocurarine and α-bungarotoxin. Pre-incubation of Bungarus fasciatus monovalent and neuro polyvalent antivenom failed to prevent the neurotoxic effects of α-elapitoxin-Bf1b in the chick biventer cervicis muscle preparation. In conclusion, the isolation of a postsynaptic neurotoxin that cannot be neutralized by either monovalent and polyvalent antivenoms may indicate the presence of isoforms of postsynaptic neurotoxins in Malaysian B. fasciatus venom.

Matched MeSH terms: Organ Culture Techniques

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