Stimulus responsive graphene scaffolds for tissue engineering

Tissue engineering (TE) is an emerging area that aims to repair damaged tissues and organs by combining different scaffold materials with living cells. Recently, scientists started to engineer a new generation of nanocomposite scaffolds able to mimic biochemical and biophysical mechanisms to modulate the cellular responses promoting the restoration of tissue structure or function. Due to its unique electrical, topographical and chemical properties, graphene is a material that holds a great potential for TE, being already considered as one of the best candidates for accelerating and guiding stem cell differentiations. Although this is a promising field there are still some challenges to overcome, such as the efficient control of the differentiation of the stem cells, especially in graphene-based microenvironments. Hence, this chapter will review the existing research related to the ability of graphene and its derivatives (graphene oxide and reduced graphene oxide) to induce stem cell differentiation into diverse lineages when under the influence of electrical, mechanical, optical and topographic stimulations

Reconstruction, Peacebuilding and Elections in Post-war Sierra Leone: A Critical Note

This article interrogates reconstruction, peacebuilding and elections in postwar Sierra Leone. It observes that while significant progress has been made, Sierra Leone’s long-term stability remains questionable due to a number of issues, including poor socioeconomic growth, the increasing political exclusion of women, corruption in government, and the growing regionalisation of political power

Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs-4

Conditions or with 10 ng/ml IL-1β and/or 10 μmol/l SB203580 for 6, 12 and 48 hours. The ratio of the relative expression level of COX-2 was calibrated to the mean value for the unstrained (untreated) control and normalized to GAPDH. Ratios were expressed on a logarithmic scale. Bars represent the mean and standard error of the mean of 16 to 18 replicates from four separate experiments. Two-way analysis of variance with Bonferroni-corrected -tests was used to compare data: **< 0.01 and ***< 0.001. COX, cyclo-oxygenase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; PG, prostaglandin.<p><b>Copyright information:</b></p><p>Taken from "Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs"</p><p>http://arthritis-research.com/content/10/2/R35</p><p>Arthritis Research & Therapy 2008;10(2):R35-R35.</p><p>Published online 18 Mar 2008</p><p>PMCID:PMC2453754.</p><p></p

Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs-0

1β for up to 45 minutes or with IL-1β and 10 μmol/l SB203580 for 20 minutes. Phospho-p38 MAPK was analyzed for each test condition using a phosphorylation state specific anti-p38 (Thr180/Tyr182) antibody (upper panel), against total p38 MAPK (middle panel) and α-tubulin as a loading control (lower panel). All cell extracts were subjected to Western blot analysis. Each band corresponds to three constructs pooled from two separate experiments. MAPK, mitogen-activated protein kinase; UT, untreated.<p><b>Copyright information:</b></p><p>Taken from "Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs"</p><p>http://arthritis-research.com/content/10/2/R35</p><p>Arthritis Research & Therapy 2008;10(2):R35-R35.</p><p>Published online 18 Mar 2008</p><p>PMCID:PMC2453754.</p><p></p

Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs-1

conditions with 0 or 10 ng/ml IL-1β and/or 10 μmol/l SB203580. Bars represent the mean and standard error of the mean of six replicates from three separate experiments. The ratio of the relative expression level for the target gene was calibrated to the mean value at time = 0 and normalized to the reference gene GAPDH. Ratios were expressed on a logarithmic scale (arbitrary units). Two-way analysis of variance with Bonferroni-corrected -tests was used to compare data under the different treatments: *< 0.05, **< 0.01 and ***< 0.001 for comparisons between time zero with IL-1β; < 0.05, < 0.01 and < 0.001 for comparisons between untreated with IL-1β or IL-1β with IL-1β plus SB203580. COX, cyclo-oxygenase; GAPDH, glyceraldehyde 3-phosphate dehydrogenase; iNOS, inducible isoforms of the nitric oxide synthase.<p><b>Copyright information:</b></p><p>Taken from "Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs"</p><p>http://arthritis-research.com/content/10/2/R35</p><p>Arthritis Research & Therapy 2008;10(2):R35-R35.</p><p>Published online 18 Mar 2008</p><p>PMCID:PMC2453754.</p><p></p

Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs-5

no treatment conditions or with 10 ng/ml IL-1β and/or 10 μmol/l SB203580 for 6, 12 and 48 hours. The ratio of the relative expression levels of the target gene was calibrated to the mean value for the unstrained (untreated) control and normalized to GAPDH. Ratios were expressed on a logarithmic scale (arbitrary units). Bars represent the mean and standard error of the mean of 10 replicates from three separate experiments. Two-way analysis of variance with Bonferroni-corrected -tests was used to compare data: *< 0.05 and ***< 0.001 between unstrained and strained values; and < 0.05 between untreated and IL-1β in unstrained constructs.<p><b>Copyright information:</b></p><p>Taken from "Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs"</p><p>http://arthritis-research.com/content/10/2/R35</p><p>Arthritis Research & Therapy 2008;10(2):R35-R35.</p><p>Published online 18 Mar 2008</p><p>PMCID:PMC2453754.</p><p></p

Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs-2

Ith 0 or 10 ng/ml IL-1β and/or 10 μmol/l SB203580. Bars represent the mean and standard error of the mean of six replicates from three separate experiments. Two-way analysis of variance with Bonferroni-corrected -tests was used to compare data under the different treatments: *< 0.05 and ***< 0.001 for comparisons between time zero with IL-1β; < 0.05, < 0.01 and < 0.001 for comparisons between untreated with IL-1β or IL-1β with IL-1β plus SB203580. PG, prostaglandin.<p><b>Copyright information:</b></p><p>Taken from "Dynamic compression counteracts IL-1β induced inducible nitric oxide synthase and cyclo-oxygenase-2 expression in chondrocyte/agarose constructs"</p><p>http://arthritis-research.com/content/10/2/R35</p><p>Arthritis Research & Therapy 2008;10(2):R35-R35.</p><p>Published online 18 Mar 2008</p><p>PMCID:PMC2453754.</p><p></p