Dental stem cells in intraoral regenerative therapy: a systematic review / Células-tronco dentárias na terapia regenerativa intraoral: uma revisão sistemática

Objective: 1) To critically review the published literature on applications of dental stem cells in the regeneration of intraoral tissues. 2) To provide an evidence-based level on research regarding application of dental stem cells in intraoral tissues regeneration. Methodology: This systematic review is conducted as per the JBI guidelines and reported as per the PRISMA. An initial literature search of papers published between 2004 and 2018 yielded 421 manuscripts. Nineteen studies satisfied the inclusion / exclusion criteria and were included for qualitative synthesis. Studies were categorized as animal (11) and human (8) trials. Five independent reviewers critically assessed the included studies. Risk of bias was assessed using SYstematic Review Centre for Laboratory animal Experimentation (SYRCLE) bias risk tool, robins-I tool for non-randomised clinical trial and Cochrane Collaboration's Tool for randomised clinical trial. Evidence levels were assessed based on JBI Criteria. Results: Animal trials mainly focused on periodontal regeneration. A high or unclear Risk of bias was more commonly found amongst animal studies. Laboratory, clinical and radiographic evaluation were used to assess the outcome. A total of Eight Human studies were conducted on a total samples size of 153 upon a wide age ranging from seven years to 60 years. Nearly 70% of the human studies used DPSC for regenerating alveolar bone defects. Conclusion: Appropriate well designed double-blind randomized clinical trials of longer duration are yet to be performed. Evidence for the included studies were 1C and 1D as per the JBI Criteria. Stem cell therapy demonstrated promising results in Periodontal tissue and alveolar bone regeneration. However, the number of studies to claim such a benefit are very limited (AU)

Objetivo: 1) Revisar criticamente a literatura publicada sobre aplicações de células-tronco dentárias na regeneração de tecidos intraorais. 2) Fornecer um nível baseado em evidências sobre pesquisas relacionadas à aplicação de células-tronco dentárias na regeneração de tecidos intraorais. Metodologia: Esta revisão sistemática é conduzida de acordo com as diretrizes do JBI e relatada de acordo com o PRISMA. Uma pesquisa bibliográfica inicial de artigos publicados entre 2004 e 2018 resultou em 421 manuscritos. Dezenove estudos satisfizeram os critérios de inclusão / exclusão e foram incluídos para síntese qualitativa. Os estudos foram categorizados como ensaios em animais (11) e humanos (8). Cinco revisores independentes avaliaram criticamente os estudos incluídos. O risco de viés foi avaliado usando a ferramenta de risco de viés do Centro de Revisão Sistemática para Experimentação com Animais de Laboratório (SYRCLE), a ferramenta robins-I para ensaios clínicos não randomizados e a Ferramenta da Colaboração Cochrane para ensaios clínicos randomizados. Os níveis de evidência foram avaliados com base nos critérios JBI. Resultados: Os ensaios em animais focaram principalmente na regeneração periodontal. Um risco alto ou pouco claro de viés foi mais comumente encontrado entre os estudos com animais. Avaliações laboratorial, clínica e radiográfica foram utilizadas para avaliar o resultado. Um total de oito estudos em humanos foram conduzidos em um tamanho total de amostras de 153 com ampla faixa etária, variando de sete a 60 anos. Quase 70% dos estudos em humanos usaram DPSC para regeneração de defeitos ósseos alveolares. Conclusão: Ensaios clínicos randomizados duplo-cegos apropriados e bem elaborados de maior duração ainda precisam ser realizados. As evidências para os estudos incluídos foram 1C e 1D de acordo com os critérios JBI. A terapia com células-tronco demonstrou resultados promissores na regeneração do tecido periodontal e do osso alveolar. No entanto, o número de estudos para reivindicar tal benefício é muito limitado (AU)

Research progress on dental pulp stem cells in the repair of peripheral nerve injury / 口腔疾病防治

@#Peripheral nerve injury (PNI) is a common disease in the oral cavity that can easily lead to loss of function and abnormal appearance. The application of dental pulp stem cells (DPSCs) combined with tissue engineering in the repair of PNI is a research hotspot. DPSCs have the advantages of abundant sources, simple extraction, low immunogenicity and a high proliferation rate in vitro. They can differentiate into Schwann cells (SCs). SCs can induce autophagy and secrete key neurotrophic factors, such as nerve growth factor, brain-derived neurotrophic factor, ciliary neurotrophic factor and glial cell-derived neurotrophic factor. SCs are beneficial for the repair of nerve injury. DPSCs in different periods have differences in immune regulation, anti-inflammatory effects, expression of neural markers, angiogenesis and so on, which provide more diversified choices for nerve repair. At present, the introduction of tissue engineering provides a more controllable and improved microenvironment for DPSCs, which is conducive to the application and development of DPSCs in regenerative medicine and tissue engineering. However, there are still many problems to be solved, such as the selection of stem cells, functional link recovery, uncontrollable direction of axon regeneration, regulation of the peripheral nervous system and mechanism of repair.

Comparison of odontoblast differentiation capacity between stem cells from human exfoliated deciduous teeth and dental pulp stem cells / 中南大学学报(医学版)

OBJECTIVES@#To explore the difference in odontoblast differentiation capacity between stem cells from human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSCs), and to examine the expression level of ephrinB1 in odontoblast differentiation of these stem cells.@*METHODS@#The stems cells were divided into a SHED group and a DPSCs group. After odontoblast differentiation induction, the above 2 groups were also randomly divided into a 3 d group and a 7 d group, respectively.The calcium deposition was detected by alkaline phosphatase (ALP) staining and alizarin red staining.The mRNA and protein expressions of ephrinB1, dentin matrix protein-1 (DMP-1) and dentin sialophosphoprotein (DSPP) were detected by real-time PCR and Western blotting.@*RESULTS@#ALP staining and alizarin red staining showed that there was stronger mineralization capacity in the SHED group than that in the DPSCs group. The relative mRNA and protein expressions of DMP-1, DSPP, and ephrinB1 in the SHED group were higher than those in the DPSCs group except for the protein expression of DMP-1 in the SHED 3 d group (all <0.05).@*CONCLUSIONS@#SHED has stronger odontoblast differentiation capacity than DPSCs. In addition, ephrinB1 may be involved in the processes of odontoblast differentiation in the SHED and DPSCs.

Characterization of the biological effect of BiodentineTM on primary dental pulp stem cells

Biodentine™ is relatively a new tricalcium silicate cement that has gained great attention of the researchers due to its biological potential in comparison with other materials. The aim of this study was to investigate the optimum concentrations of Biodentine in relation to its stimulatory or inhibitory effect on proliferation, migration and adhesion of stem cells of human exfoliated deciduous teeth (SHED). The cell cultures of SHED were treated with Biodentine™ extract at four different concentrations; 20mg/ml, 2mg/ml, 0.2mg/ml and 0.02mg/ml. Cells cultured without Biodentine™ were kept as a blank control. The proliferation potential of SHED cells was evaluated by MTT viability analysis for 6 days. Migration potential was investigated by wound healing and transwell migration assays. The growth, survival and communication potential of these cells was determined by Adhesion assay. Results: A significant increase was observed in the proliferation and migration of SHED at (2mg/ml, 0.2mg/ml and 0.02mg/ml) while higher concentration of Biodentine™ (20mg/ml) exhibited cytotoxic effect on the cells. However, three tested Biodentine™ concentrations were similar in effect (non-significant) to adhesion ability of cells when compared with blank control. Conclusion: Our findings suggest that lower concentrations of Biodentine™ can be considered as the optimum concentrations to enhance the stimulatory effect of Biodentine on SHED.

Clinical applications of stem cells from human exfoliated deciduous teeth in stem cell therapy / 华西口腔医学杂志

Stem cells from human exfoliated deciduous teeth (SHED) are one category of dental stem cells. They belong to ectodermal mesenchymal stem cells. As an ideal stem cell source, SHED possess great potential in stem cell therapy. This review demonstrates the biological characteristics and advantages of SHED in stem cell therapy and discusses its multiple functions in tissue regeneration and repair, including multiple differentiation potentiality, cell secretion of cytokines, and immunomodulatory ability. Furthermore, this article introduces the main findings regarding the potential clinical applications of SHED to a variety of diseases. This article demonstrates research progress in dentin-pulp regeneration, maxillofacial bone regeneration, and treatment of nervous system and immune system diseases with SHED for stem cell transplantation.

Indirect Co-Culture of Stem Cells from Human Exfoliated Deciduous Teeth and Oral Cells in a Microfluidic Platform

Oral epithelial-mesenchymal interactions play a key role in tooth development and assist differentiation of dental pulp. Many epithelial and mesenchymal factors in the microenvironment influence dental pulp stem cells to differentiate and regenerate. To investigate the interaction between oral cells during differentiation, we designed a microfluidic device system for indirect co-culture. The system has several advantages, such as consumption of low reagent volume, high-throughput treatment of reagents, and faster mineralization analysis. In this study, stem cells from human exfoliated deciduous teeth were treated with media cultured with human gingival fibroblasts or periodontal ligament stem cells. When human exfoliated deciduous teeth was incubated in media cultured in human gingival fibroblasts and human periodontal ligament stem cells under the concentration gradient constructed by the microfluidic system, no remarkable change in human exfoliated deciduous teeth mineralization efficiency was detected. However, osteoblast gene expression levels in human exfoliated deciduous teeth incubated with human gingival fibroblasts media decreased compared to those in human exfoliated deciduous teeth treated with human periodontal ligament stem cells media, suggesting that indirect co-culture of human exfoliated deciduous with human gingival fibroblasts may inhibit osteogenic cytodifferentiation. This microfluidic culture device allows a co-culture system set-up for sequential treatment with co-culture media and differentiation additives and facilitated the mineralization assay in a micro-culture scale.

Influence of three types of scaffolds on biological behavior of stem cells from human exfoliated deciduous teeth / 实用口腔医学杂志

Objective:To investigate the adhesion,proliferation and differentiation of the stem cells from human exfoliated deciduous teeth(SHEDs)on 3 different types of hydroxyapatite(HA)composite scaffold materials.Methods:Pulp cells from human exfoliated de-ciduous teeth were harvested from impacted deciduous teeth by enzyme digestion,expanded and cultured.Cells were verified by immuno-histochemical methods and in vitro differentiation test.Then the cells were cultured on HA/beta tricalcium phosphate (HA/TCP),HA/collagen (HA/COL)and HA/poly-ethylene propylene lactide (HA/PLGA)scaffold respectively.Adhesion rate was examined at hour 4,6,8 and 10 of culture,proliferation was observed by MTT assay on day 1,4,7 and 10 of culture,respectively.The osteogenic dif-ferentiation was studied by alkaline phosphatase(ALP)test,Von Kossa staining and calcium content measur.Results:The attachment of SHEDs was significantly lower on the HA/COL than on the other 2 scaffolds(P <0.05).The ALP activity,mineralization and calci-um content were the highest on HA/PLGA,and the last on HA/COL(P <0.05).Conclusion:HA/PLGA scaffold is more effective in the promotion of the proliferation,attachment and differentiation of SHEDs than HA/TCP and HA/COL scaffolds.

Progress in the study of dental tissue-derived stem cells / 实用口腔医学杂志

Dental stem cells(DSCs)possess the characteristics of stem cells and can be effectively obtained from iatro-waste products (such as impacted wisdom tooth and the extracted teeth for orthodontic reason).It has been proved that DSCs are the important sources of stem cells for tissue engineering and regenerative medicine research.Research of these stem cells will create broader space for tissue engi-neering and regenerative medicine and will have important values in translational research.This review gives an overview of the research pro-gress of dental stem cells,and presents some new findings of several common dental stem cells as well as the application in tissue regenera-tion.

Differentiation of odontoblast-like cells from human exfoliated deciduous teeth-derived stem cells by transforming growth factor β3 in combination with heparin in vitro / 实用医学杂志

Objective To investigate the ability of human exfoliated deciduous teeth-derived stem cells (SHED) to differentiate into odontoblast-like cells. Methods SHEDs were isolated by enzyme digestion method. The 3nd passage SHEDs were incubated with 25 ng/mL recombinant human TGF-β3 , or with TGF-β3 in combination with heparin. The DSPP expression was detected by Q-PCR and Western-blotting assay. Alizarin red staining, immunhistochemistry assay and alkaline phosphatase(AKP) activity assay were performed, respectively. Result The AKP activity was enhance by TGF-β3 in combination with heparin. Alizarin red staining was positive in TGF-β3-heparin groups, with the increase of DSPP expression at both mRNA and protein level. Conclusion TGF-β3 in combination with heparin can enhance the differentiation of human exfoliated deciduous teeth-derived stem cells into odontoblast-like cells.

Modified platelet-rich plasma promotes the osteogenic differentiation of stem cells from human exfoliated deciduous teeth / 实用口腔医学杂志

Objective:To investigate the effect of modified plateletrich plasma(mPRP)on the osteogenic differentiation of stemcells from human exfoliated deciduous teeth(SHED).Methods:mPRP at 1%,2%,5%,10% and FBS at 10% were added to thecultured SHED of passage 4,respectively.The influence of mPRP on alkaline phosphatase(ALP)activity was evaluated using ALPkit.RUNX2 and osteocalcin mRNA expression in the treated cells were examined by realtime PCR.Results:mPRP enhanced ALPactivity in the SHED,and the effect of mPRP was more obvious at 2%.Treatment of the cells with 2% mPRP upregulated the mRNAexpressions of RUNX2 and osteocalcin.Conclusion:mPRP can promote the osteogenic differentiation of SHED.

The Immunologic Properties of Undifferentiated Stem Cells from Human Exfoliated Deciduous Teeth (SHED) and Its Potential Application in Bone Regeneration

Stem cells from human exfoliated deciduous teeth (SHED) are highly proliferative, clonogenic cells capable of differentiating into osteoblasts and inducing bone formation. It is a potential alternative for stem cell bone regeneration therapy. However, stem cell therapy carries the risk of immune rejection mediated by inflammatory cytokines of the human defense system. Objective: This preliminary research studies the interaction between SHED and the immune system by determining the inflammatory cytokines profile and osteogenic potential of SHED. Methods: Human fetal osteoblasts (hFOb) cell line and isolated SHED were cultured and total RNA was extracted, followed by reverse transcription cDNA synthesis. Semi-quantitative reverse transcription PCR and Multiplex PCR were performed to detect the expression levels of OPG/RANKL and TNF-α, IL-1β, IL-6, IL-8 and TGF-β in both cell types. Results: Analysis showed that SHED expressed significantly lower amounts of IL-1β, IL-6, and IL-8 compared to hFOB. IL-1β is a potent bone-resorbing factor, while IL-6 and IL-8 induce osteoclastogenesis and osteolysis respectively. SHED did not express TNF-α which stimulates osteoclastic activity. SHED demonstrated high OPG/RANKL ratio, in contrast with that of marrow stem cells described in previous studies. Our findings suggest that SHED may have improved immunomodulatory profile in terms of promoting relatively lower inflammatory reaction during transplant and enhancing bone regeneration. Conclusion: SHED has a potential to be a good source of osteoblasts for bone regeneration therapy. Further studies on the immunomodulatory properties of SHED-derived osteoblasts are necessary to enable stem cell therapy in immunocompetent hosts.

Redefining the potential applications of dental stem cells: An asset for future.

Recent exciting discoveries isolated dental stem cells from the pulp of the primary and permanent teeth, from the periodontal ligament, and from associated healthy tissues. Dental pulp stem cells (DPSCs) represent a kind of adult cell colony which has the potent capacity of self-renewing and multilineage differentiation. Stem cell-based tooth engineering is deemed as a promising approach to the making of a biological tooth (bio-tooth) or engineering of functional tooth structures. Dental professionals have the opportunity to make their patients aware of these new sources of stem cells that can be stored for future use as new therapies are developed for a range of diseases and injuries. The aim of this article is to review and understand how dental stem cells are being used for regeneration of oral and conversely nonoral tissues. A brief review on banking is also done for storing of these valuable stem cells for future use.

Dental stem cells: Dentinogenic, osteogenic, and neurogenic differentiation and its clinical cell based therapies.

Each year approximately $400 billion is spent treating Americans suffering some type of tissue loss or end-stage organ failure. This includes millions of dental and oral craniofacial procedure, ranging from tooth restorations to major reconstruction of facial soft and mineralized tissue. Recently, a population of putative post-natal stem cells in human dental pulp (DPSCs) has been identified within the "cell- rich zone" of dental pulp. The other type of stem cells from human exfoliated deciduous teeth (SHED) was identified to be a population of highly proliferative, clonogenic cells. Dental Pulp Stem Cells (DPSCs) can not only be derived from a very accessible tissue resource like SHED but are also capable of providing enough cells for potential cell-based therapies.