Lithiated porous silicon nanowires stimulate periodontal regeneration

Periodontal disease is a significant burden for oral health, causing progressive and irreversible damage to the support structure of the tooth. This complex structure, the periodontium, is composed of interconnected soft and mineralised tissues, posing a challenge for regenerative approaches. Materials combining silicon and lithium are widely studied in periodontal regeneration, as they stimulate bone repair via silicic acid release while providing regenerative stimuli through lithium activation of the Wnt/β-catenin pathway. Yet, existing materials for combined lithium and silicon release have limited control over ion release amounts and kinetics. Porous silicon can provide controlled silicic acid release, inducing osteogenesis to support bone regeneration. Prelithiation, a strategy developed for battery technology, can introduce large, controllable amounts of lithium within porous silicon, but yields a highly reactive material, unsuitable for biomedicine. This work debuts a strategy to lithiate porous silicon nanowires (LipSiNs) which generates a biocompatible and bioresorbable material. LipSiNs incorporate lithium to between 1% and 40% of silicon content, releasing lithium and silicic acid in a tailorable fashion from days to weeks. LipSiNs combine osteogenic, cementogenic and Wnt/β-catenin stimuli to regenerate bone, cementum and periodontal ligament fibres in a murine periodontal defect

Dental pulp tissue engineering

Dental pulp is a highly specialized mesenchymal tissue, which have a restrict regeneration capacity due to anatomical arrangement and post-mitotic nature of odontoblastic cells. Entire pulp amputation followed by pulp-space disinfection and filling with an artificial material cause loss of a significant amount of dentin leaving as life-lasting sequelae a non-vital and weakened tooth. However, regenerative endodontics is an emerging field of modern tissue engineering that demonstrated promising results using stem cells associated with scaffolds and responsive molecules. Thereby, this article will review the most recent endeavors to regenerate pulp tissue based on tissue engineering principles and providing insightful information to readers about the different aspects enrolled in tissue engineering. Here, we speculate that the search for the ideal combination of cells, scaffolds, and morphogenic factors for dental pulp tissue engineering may be extended over future years and result in significant advances in other areas of dental and craniofacial research. The finds collected in our review showed that we are now at a stage in which engineering a complex tissue, such as the dental pulp, is no longer an unachievable and the next decade will certainly be an exciting time for dental and craniofacial research

Expression and regulation of PAX-9 and MSX-1 in embryonic and post-natal dental stem cells.

Introduction: Msx1and Pax9, are genes expressed in mesenchymal cells during the odontogenesis that are required for tooth formation. Our investigation aimed to study the expression of these genes in two sources of dental mesenchymal cells. Stem Cells from Human Exfoliated Deciduous teeth (SHED) and Human Embryonic Dental Mesenchymal Cells (HTM) were used. Regulation of gene expression in these cells by FGF, Wnt, BMP4 and Shh signalling pathways together with the effects of tooth matrix proteins (EMD) was investigated. Materials and Methods: Cells were grown in 6 well plates in 3 ml MSCGM medium (Lonza) containing Glutamax, 10% FBS and gentamicin Sulfate. Cells were grown to confluence and when 80% confluent, they were treated for 24 hours with either 20 ng per ml BIO (Gsk3 inhibitor), 1.5µl per ml of porcine dental matrix proteins (EMD), 0.4µl per ml of Fgf8 and 4µl per ml of DMSO (control). RNA was extracted and purified according the RNeasy-kit-protocol from Qiagen. RNA quantitation was done using a Bio Photometer (Eppendorf) in 2:100 dilutions of the samples with nuclease-free water. Quantitative analysis was performed using Rotor Gene Q-serier softhware. 10µl of mixture was made with 5µl of Sensimix- syber green from Quantace, 0.2µl F- primer , 0.2µl R-primer and 4.6µl of cDNA. Results: Complex patterns of changes in the levels of gene expression were observed that were both cell and treatment specific. In particular BMP4 treatment resulted in large upregulation of Msx1 and Pax9 gene expression in both cell types. Differences in gene expression observed between HTM and SHED cells identify possible reasons why SHED cells respond differently to HTM in tissue recombinations directed towards producing biological replacement teeth

Electroweak parameters of the z0 resonance and the standard model

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