Role of Adipose-Derived Mesenchymal Stem Cells in Bone Regeneration.

Bone regeneration involves multiple factors such as tissue interactions, an inflammatory response, and vessel formation. In the event of diseases, old age, lifestyle, or trauma, bone regeneration can be impaired which could result in a prolonged healing duration or requiring an external intervention for repair. Currently, bone grafts hold the golden standard for bone regeneration. However, several limitations hinder its clinical applications, e.g., donor site morbidity, an insufficient tissue volume, and uncertain post-operative outcomes. Bone tissue engineering, involving stem cells seeded onto scaffolds, has thus been a promising treatment alternative for bone regeneration. Adipose-derived mesenchymal stem cells (AD-MSCs) are known to hold therapeutic value for the treatment of various clinical conditions and have displayed feasibility and significant effectiveness due to their ease of isolation, non-invasive, abundance in quantity, and osteogenic capacity. Notably, in vitro studies showed AD-MSCs holding a high proliferation capacity, multi-differentiation potential through the release of a variety of factors, and extracellular vesicles, allowing them to repair damaged tissues. In vivo and clinical studies showed AD-MSCs favoring better vascularization and the integration of the scaffolds, while the presence of scaffolds has enhanced the osteogenesis potential of AD-MSCs, thus yielding optimal bone formation outcomes. Effective bone regeneration requires the interplay of both AD-MSCs and scaffolds (material, pore size) to improve the osteogenic and vasculogenic capacity. This review presents the advances and applications of AD-MSCs for bone regeneration and bone tissue engineering, focusing on the in vitro, in vivo, and clinical studies involving AD-MSCs for bone tissue engineering.

Accuracy of conventional versus cone-beam CT-synthesised lateral cephalograms for cephalometric analysis: A systematic review.

OBJECTIVE: To assess the accuracy of cone-beam computed tomography (CBCT)-synthesised lateral cephalograms (CSLCs) compared with conventional lateral cephalograms for cephalometric analysis in human participants and skull models. METHODS: The authors performed a search of PubMed, Scopus, Google Scholar and Embase databases on 4 October 2021. Included studies met the following criteria: published in English; compared conventional lateral cephalograms and CSLCs; assessed hard- and soft-tissue landmarks; and were performed on human or skull models. Data extraction from eligible studies was performed by two independent reviewers. The quality of evidence was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist tool - diagnostic accuracy studies. RESULTS: A total of 20 eligible articles were included in this systematic review. Of these 20 studies, 17 presented with a low risk of bias, while three were found to have a moderate risk of bias. Hard- and soft-tissue analyses were evaluated for each imaging modality. The findings reveal that CSLCs are accurate and comparable to conventional lateral cephalograms for cephalometric analysis and demonstrate good inter-observer reliability. Four studies reported a higher accuracy with CSLCs. CONCLUSION: Overall, the diagnostic accuracy and reproducibility of CSLCs were comparable to conventional lateral cephalograms in cephalometric analysis. It is justified that patients who have an existing CBCT scan do not need an additional lateral cephalogram, minimising unnecessary radiation exposure, expenses and time for the patient. Larger voxel sizes and low-dose CBCT protocols can be considered to minimise radiation exposure. REGISTRATION: This study was registered with PROSPERO (CRD42021282019).

Use of cyanoacrylate tissue adhesives for wound closure in the head and neck region: A systematic review.

BACKGROUND: Wound closure in the head and neck region is challenging, primarily due to aesthetic concerns. Tissue adhesives have been prized for their ease of use. This study aimed to compare the effectiveness of tissue adhesives as a suitable alternative to other conventional wound closure techniques, in the head and neck region. METHODS: A systematic review was conducted in line with PRISMA guidelines. Available English literature from 2009 to 2019 was reviewed from PubMed, Scopus and Google Scholar. Randomized controlled trials and controlled clinical trials with wounds in the head and neck region were included in this study. RESULTS: Sixteen articles were found to meet the inclusion criteria. Main outcomes assessed included the following: cosmesis, pain, swelling, bleeding, wound dehiscence, time and cost. There was significant heterogeneity in results for pain, swelling and bleeding. No significant difference was observed in wound dehiscence and long-term cosmetic outcome when tissue adhesives were compared with sutures and staples. The time taken for wound closure with tissue adhesives was faster than sutures but were conflicted when compared with staples. Cost was found to be similar. CONCLUSION: Overall, there is a consensus that there is no long-term difference in cosmetic outcome and wound dehiscence between tissue adhesives and other wound closure techniques. Tissue adhesives have the benefit of being easy and quick to use with excellent patient satisfaction levels. We recommend tissue adhesives as a suitable alternative for wound closure in low tension areas in the head and neck region.

Katanin p80 regulates human cortical development by limiting centriole and cilia number.

Katanin is a microtubule-severing complex whose catalytic activities are well characterized, but whose in vivo functions are incompletely understood. Human mutations in KATNB1, which encodes the noncatalytic regulatory p80 subunit of katanin, cause severe microlissencephaly. Loss of Katnb1 in mice confirms essential roles in neurogenesis and cell survival, while loss of zebrafish katnb1 reveals specific roles for katnin p80 in early and late developmental stages. Surprisingly, Katnb1 null mutant mouse embryos display hallmarks of aberrant Sonic hedgehog signaling, including holoprosencephaly. KATNB1-deficient human cells show defective proliferation and spindle structure, while Katnb1 null fibroblasts also demonstrate a remarkable excess of centrioles, with supernumerary cilia but deficient Hedgehog signaling. Our results reveal unexpected functions for KATNB1 in regulating overall centriole, mother centriole, and cilia number, and as an essential gene for normal Hedgehog signaling during neocortical development.

The generation of GLP-grade human embryonic stem cell banks from four clinical-grade cell lines for preclinical research.

The Singapore Stem Cell Bank has generated human embryonic stem cell banks from clinical-grade cell lines ESI-017, ESI-035, ESI-049, and ESI-053. All banks were prepared and characterized according to principles of Good Laboratory Practice for quality assurance. Importantly, each cell line has clearly documented and approved ethical provenance and meets recognized standards for performance and safety. The banks are intended to facilitate the translation of stem cell research to clinical medicine by enabling early phase research and development with high-quality, low-cost cells that are also available as clinical-grade stocks.