Azlina Ahmad

Evaluation of Tualang honey as a supplement to fetal bovine serum in cell culture

The aim of this study was to evaluate Tualang honey as a supplement to fetal bovine serum in cell cultures using MTT assay, chromosome aberration test and gene expression analyses. The MTT assay showed the highest percentage of cell proliferation (105.3% increment than control) of human osteoblast cell line (CRL 1543) in 0.0195% honey in Dulbeccos modified eagle medium supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin. There was enhanced cell proliferation corresponding to the decrease in concentrations of honey as indicated by the mitotic index values when the osteoblast cell line was incubated at 37 degrees C for 48 hours. There were no chromosome aberrations both in the honey treated as well as distilled water treated (negative control) cell lines. In the case of gene expression analyses, fibroblast cell lines (CCL 171) were treated with honey (0.0195%) for 24 and 48 hours separately. Though there was over expression for the bcl-xl gene at both 24 and 48 hours, under expression for bcl-xs gene at 24 hours and over expression at 48 hours and under expression for both c-myc and p53 genes at both 24 and 48 hours, none of them were statistically significant in altering the expression of mRNA.

Cell attachment properties of Portland cement-based endodontic materials: biological and methodological considerations.

INTRODUCTION The attachment and spreading of mammalian cells on endodontic biomaterials are an area of active research. The purpose of this review is to discuss the cell attachment properties of Portland cement (PC)-based materials by using scanning electron microscope (SEM). In addition, methodological aspects and technical challenges are discussed. METHODS A PubMed electronic search was conducted by using appropriate key words to identify the available investigations on the cell attachment properties of PC-based endodontic materials. After retrieving the full text of related articles, the cross citations were also identified. RESULTS A total of 23 articles published between January 1993 and October 2013 were identified. This review summarizes the cell attachment properties of commercial and experimental PC-based materials on different cell cultures by using SEM. Methodological procedures, technical challenges, and relevance of SEM in determining the biological profile of PC-based materials are discussed. CONCLUSIONS SEM observations demonstrate that commercial MTA formulations show favorable cell attachment properties, which is consistent with their successful clinical outcomes. The favorable cell attachment properties of PC and its modified formulations support its potential use as a substitute for mineral trioxide aggregate. However, researchers should carefully select cell types for their SEM investigations that would be in contact with the proposed PC-based combinations in the clinical situation. Despite being a technical challenge, SEM provides useful information on the cell attachment properties of PC-based materials; however, other assays for cell proliferation and viability are essential to come up with an accurate in vitro biological profile of any given PC-based formulation.

Transforming Growth Factor-α and Nonsyndromic Cleft Lip With or Without Palate or Cleft Palate Only in Kelantan, Malaysia

Objective: To determine the frequency of the transforming growth factor-alpha (TGFα) Taq1 polymorphism in nonsyndromic cleft lip with or without cleft palate (CL±P) and cleft palate only (CP) in Kelantan, Malaysia. Setting: The study was conducted at the Combined Cleft Clinic and at the Human Genome Centre in Hospital Universiti Sains Malaysia in Kelantan, Malaysia. Design: We examined the C2/Taq1 variant of the TGFα gene in 46 patients with nonsyndromic CL±P or CP only and in 33 controls. The TGFα genotype frequencies in patients were compared with those in controls using the chi-square or Fisher exact test. DNA samples were obtained from peripheral blood. Results: No association was found between TGFαTaq1 polymorphism and CL±P or CP in this case-control study. In addition, no homozygosity for the rare allele C2 was noted in CL±P, CP, or the controls. Conclusion: No evidence of TGFαTaq1 polymorphism was observed in association with CL±P and CP in this study.

Angiogenic potential of extracellular matrix of human amniotic membrane

Combination between tissue engineering and other fields has brought an innovation in the area of regenerative medicine which ultimate aims are to repair, improve, and produce a good tissue construct. The availability of many types of scaffold, both synthetically and naturally have developed into many outstanding end products that have achieved the general objective in tissue engineering. Interestingly, most of this scaffold emulates extracellular matrix (ECM) characteristics. Therefore, ECM component sparks an interest to be explored and manipulated. The ECM featured in human amniotic membrane (HAM) provides a suitable niche for the cells to adhere, grow, proliferate, migrate and differentiate, and could possibly contribute to the production of angiogenic micro-environment indirectly. Previously, HAM scaffold has been widely used to accelerate wound healing, treat bone related and ocular diseases, and involved in cardiovascular repair. Also, it has been used in the angiogenicity study, but with a different technical approach. In addition, both side of HAM could be used in cellularised and decellularised conditions depending on the objectives of a particular research. Therefore, it is of paramount importance to investigate the behavior of ECM components especially on the stromal side of HAM and further explore the angiogenic potential exhibited by this scaffold.

Immunomodulatory Effect of Cytokines in the Differentiation of Mesenchymal Stem Cells: A Review

Mesenchymal stem cells (MSCs) are stromal origin cells with multilineage differentiation capacity. The immunoregulatory properties of MSCs can be interfered effectively by cytokines. Cytokines, produced by a broad range of cells, act at the systemic level to influence biological phenomena such as inflammation, wound healing, organogenesis and oncogenesis. Cytokines also play vital roles in the differentiation of MSCs into several cell lineages. This review summarizes on how cytokines can affect MSCs differentiation and their relative signaling pathways, which may serve to understand the possible underlying mechanisms. Also, this review reveals the potential clinical use of MSCs as promising therapeutic agents due to their special characteristics such as multipotent differentiation, immunomodulatory properties, and selfrestoration.

Chemical analysis and biological properties of two different formulations of white portland cements.

White Portland cement (WPC) has generated research interests in the field of endodontics. This study compared between the properties of two formulations of white Portland cement (WPC) of different origin (Malaysia [MA] and Egypt [EG]). WPCs with and without calcium chloride dihydrate were prepared. Scanning electron microscope (SEM), energy dispersive X-ray micro-analysis, and X-ray diffraction were used for surface morphology evaluation, elemental, and phase analysis, respectively. After the preparation of optimized serial dilutions, the cytotoxicity was evaluated on human periodontal ligament fibroblasts (HPLFs) and dental pulp stem cells (DPSCs) using methyl-thiazol-diphenyltetrazolium assay after 24 and 72 h. Cell attachment properties were examined under SEM after 24 and 72 h. Results showed that the surface morphology and chemical composition of both formulations demonstrated detectable variations. The cytotoxicity evaluation showed different cellular responses of HPLFs compared to DSPCs. Both formulations favored the viability of HPLFs. However, the fast set formulations demonstrated severe cytotoxicity on DPSCs. Significant differences between EGWPC and MAWPC were identified (p < 0.05). The cell attachment properties were favorable; however, HPLFs attached and spread over the samples better than DPSCs. In conclusion, WPC of different origin may show differences in chemical and biological properties. The addition of CaCl2 ·2H2 O to WPC can affect its properties. Human cell types may react differently towards different formulations of WPCs. SCANNING 38:303-316, 2016.

Age and Disease Related Telomere Manifestations - A Review

Telomeres are long repetitive DNA sequences of TTAGGG located at the end of the linear chromosomes and bound by shelterin proteins. Shelterin proteins function as the protection for the loop structure of telomere, which prevents the chromosome ends uncapped; resemble a DNA break and activates DNA repair mechanism. Telomeres are maintained by an enzyme called telomerase. Telomerase is not expressed in normal human somatic cells. Therefore, telomeres shorten with every cell division and limit the number of cell division. This limitation of cell division is termed replicative aging, which is thought to be a barrier to cancer formation. In addition, telomere shortening can induce replicative senescence which then leads to aging and human aging-associated diseases such as cancer and atherosclerosis. Several studies on human premature aging diseases such as congenital dyskeratosis and aplastic anemia also reported association between them and telomere length.

Optimization of scanning electron microscope technique for amniotic membrane investigation: A preliminary study

Objective: The objective of this study was to evaluate and compare the two scanning electron microscope (SEM) preparation protocols and determine the better SEM preparation technique to study stem cells on human amniotic membrane (hAM) scaffold. Materials and Methods: Formaldehyde-based protocol and glutaraldehyde-based protocol were compared to evaluate the quality of SEM images for stem cells cultured on hAM scaffold. Results: The results suggested that formaldehyde-based protocol is better than glutaraldehyde-based protocol in terms of showing clearer topography of the membrane as well as the boarders of the cells. To provide intact surface of the SEM sample and avoid possible ruptures of the hAM or the thin cell layer, it is recommended to perform the dehydration step using graded alcohol concentrations of 20%, 30%, 40%, 50%, 60%, 70%, 80%, and 90%, one time for each and twice in 100% for 10 min each. Gold sputter-coating step is not recommended as it does not improve the image quality. Conclusions: To obtain clear SEM images, it is recommended to run a preliminary study to determine the better chemicals and conditions of sample preparation even when following preexisting protocols.

Biological Interaction Between Human Gingival Fibroblasts and Vascular Endothelial Cells for Angiogenesis: A Co-culture Perspective

Advancement in cell culture protocols, multidisciplinary research approach, and the need of clinical implication to reconstruct damaged or diseased tissues has led to the establishment of three-dimensional (3D) test systems for regeneration and repair. Regenerative therapies, including dental tissue engineering, have been pursued as a new prospect to repair and rebuild the diseased/lost oral tissues. Interactions between the different cell types, growth factors, and extracellular matrix components involved in angiogenesis are vital in the mechanisms of new vessel formation for tissue regeneration. In vitro pre-vascularization is one of the leading scopes in the tissue-engineering field. Vascularization strategies that are associated with co-culture systems have proved that there is communication between different cell types with mutual beneficial effects in vascularization and tissue regeneration in two-dimensional or 3D cultures. Endothelial cells with different cell populations, including osteoblasts, smooth muscle cells, and fibroblasts in a co-culture have shown their ability to advocate pre-vascularization. In this review, a co-culture perspective of human gingival fibroblasts and vascular endothelial cells is discussed with the main focus on vascularization and future perspective of this model in regeneration and repair.

White mineral trioxide aggregate mixed with calcium chloride dihydrate: chemical analysis and biological properties

Objectives This study aimed to evaluate the chemical and biological properties of fast-set white mineral trioxide aggregate (FS WMTA), which was WMTA combined with calcium chloride dihydrate (CaCl2·2H2O), compared to that of WMTA. Materials and Methods Surface morphology, elemental, and phase analysis were examined using scanning electron microscope (SEM), energy dispersive X-ray microanalysis (EDX), and X-ray diffraction (XRD), respectively. The cytotoxicity and cell attachment properties were evaluated on human periodontal ligament fibroblasts (HPLFs) using methyl-thiazol-diphenyltetrazolium (MTT) assay and under SEM after 24 and 72 hours, respectively. Results Results showed that the addition of CaCl2·2H2O to WMTA affected the surface morphology and chemical composition. Although FS WMTA exhibited a non-cytotoxic profile, the cell viability values of this combination were lesser than WMTA, and the difference was significant in 7 out of 10 concentrations at the 2 time intervals (p < 0.05). HPLFs adhered over the surface of WMTA and at the interface, after 24 hours of incubation. After 72 hours, there were increased numbers of HPLFs with prominent cytoplasmic processes. Similar findings were observed with FS WMTA, but the cells were not as confluent as with WMTA. Conclusions The addition of CaCl2·2H2O to WMTA affected its chemical properties. The favorable biological profile of FS WMTA towards HPLFs may have a potential impact on its clinical application for repair of perforation defects.