Therapeutic and regenerative potential of different sources of mesenchymal stem cells for cardiovascular diseases

Mesenchymalstemcells(MSCs)areidealcandidatesfortreatingmanycardiovasculardiseases.MSCscanmodify the internal cardiac microenvironment to facilitate their immunomodulatory and differentiation abilities,which are essential to restore heart function.MSCs can be easily isolated from different sources,including bone marrow,adipose tissues,umbilical cord,and dental pulp.MSCs from various sources differ in their regenerative and therapeutic abilities for cardiovascular disorders.In this review,we will summarize the therapeutic potential of each MSC source for heart diseases and highlight the possible molecular mechanisms of each source to restore cardiac function.

Mesenchymal Stem Cells and Tooth Engineering

Tooth loss compromises human oral health. Although several prosthetic methods, such as artificial denture and dental implants, are clinical therapies to tooth loss problems, they are thought to have safety and usage time issues. Recently, tooth tissue engineering has attracted more and more attention. Stem cell based tissue engineering is thought to be a promising way to replace the missing tooth. Mesenchymal stem cells （MSCs） are multipotent stem cells which can differentiate into a variety of cell types. The potential MSCs for tooth regeneration mainly include stem cells from human exfoliated deciduous teeth （SHEDs）, adult dental pulp stem cells （DPSCs）, stem cells from the apical part of the papilla （SCAPs）, stem cells from the dental follicle （DFSCs）, periodontal ligament stem cells （PDLSCs） and bone marrow derived mesenchymal stem cells （BMSCs）. This review outlines the recent progress in the mesenchymal stem cells used in tooth regeneration.

Potential of dental pulp stem cells and their products in promoting peripheral nerve regeneration and their future applications

Peripheral nerve injury(PNI)seriously affects people’s quality of life.Stem cell therapy is considered a promising new option for the clinical treatment of PNI.Dental stem cells,particularly dental pulp stem cells(DPSCs),are adult pluripotent stem cells derived from the neuroectoderm.DPSCs have significant potential in the field of neural tissue engineering due to their numerous advantages,such as easy isolation,multidifferentiation potential,low immunogenicity,and low transplant rejection rate.DPSCs are extensively used in tissue engineering and regenerative medicine,including for the treatment of sciatic nerve injury,facial nerve injury,spinal cord injury,and other neurodegenerative diseases.This article reviews research related to DPSCs and their advantages in treating PNI,aiming to summarize the therapeutic potential of DPSCs for PNI and the underlying mechanisms and providing valuable guidance and a foundation for future research.

Dental pulp stem cells and banking of teeth as a lifesaving therapeutic vista

Exfoliated deciduous or an extracted healthy adult tooth can be used to harvest,process,and cryogenically preserve dental pulp stem cells.Future stem cell-based regenerative medicine methods could benefit significantly from these mesenchymal stem cells.Teeth serve as a substantial source of mesenchymal stem cells,otherwise disposed of as medical waste.Care should be taken to store this treasure trove of stem cells.Collective responsibility of patients,dentists,and physicians is necessary to ensure that this valuable resource is not wasted and that every possible dental pulp stem cell is available for use in the future.The dental pulp stem cells(DPSC)inside teeth represent a significant future source of stem cells for regenerative medicine procedures.This review describes the ontogeny,the laboratory processing and collection,and isolation methods of DPSC.This review also discusses currently available stem cell banking facilities and their potential use in regenerative medicine procedures in dental and general medical applications in the future.

Dental pulp stem cells express tendon markers under mechanical loading and are a potential cell source for tissue engineering of tendon-like tissue

Postnatal mesenchymal stem cells have the capacity to differentiate into multiple cell lineages. This study explored the possibility of dental pulp stem cells （DPSCs） for potential application in tendon tissue engineering. The expression of tendon- related markers such as scleraxis, tenascin-C, tenomodulin, eye absent homologue 2, collagens I and VI was detected in dental pulp tissue. Interestingly, under mechanical stimulation, these tendon-related markers were significantly enhanced when DPSCs were seeded in aligned polyglycolic acid （PGA） fibre scaffolds. Furthermore, mature tendon-like tissue was formed after transplantation of DPSC-PGA constructs under mechanical loading conditions in a mouse model. This study demonstrates that DPSCs could be a ootential stem cell source for tissue enEineerin~ of tendon-like tissue.

Single CD271 marker isolates mesenchymal stem cells from human dental pulp

Mesenchymal stem cells （MSCs） are a promising tool in regenerative medicine due to their capacity to differentiate into multiple lineages. In addition to MSCs isolated from bone marrow （BMSCs）, adult MSCs are isolated from craniofacial tissues including dental pulp tissues （DPs） using various stem cell surface markers. However, there has been a lack of consensus on a set of surface makers that are reproducibly effective at isolating putative multipotent dental mesenchymal stem cel^s （~M^Cs）. II1 ~his stucly, we used clif^et（~nt combinations of surface markers （CD51/CD140a, CD271, and STRO-1/CD146） to isolate homogeneous populations of DMSCs from heterogeneous dental pulp cells （DPCs） obtained from DP and compared their capacity to undergo multilineage differentiation. Fluorescence-activated cell sorting revealed that 27.3% of DPCs were CD51＋/CD140a＋, 10.6% were CD271＋, and 0.3% were STRO-1＋/CD146＋. Under odontogenic conditions, all three subsets of isolated DMSCs exhibited differentiation capacity into odontogenic lineages. Among these isolated subsets of DMSCs, CD271＋ DMSCs demonstrated the greatest odontogenic potential. While all three combinations of surface markers in this study successfully isolated DMSCs from DPCs, the single CD271 marker presents the most effective stem cell surface marker for identification of DMSCs with high odontogenic potential. Isolated CD271＋ DMSCs could potentially be utilized for future clinical applications in dentistry and regenerative medicine.

Human dental pulp stem cells: Applications in future regenerative medicine

Stem cells are pluripotent cells, having a property of differentiating into various types of cells of human body. Several studies have developed mesenchymal stem cells(MSCs) from various human tissues,peripheral blood and body fluids. These cells are then characterized by cellular and molecular markers to understand their specific phenotypes. Dental pulp stem cells(DPSCs) are having a MSCs phenotype and they are differentiated into neuron, cardiomyocytes, chondrocytes, osteoblasts, liver cells and β cells of islet of pancreas. Thus, DPSCs have shown great potentiality to use in regenerative medicine for treatment of various human diseases including dental related problems. These cells can also be developed into induced pluripotent stem cells by incorporation of pluripotency markers and use for regenerative therapies of various diseases. The DPSCs are derived from various dental tissues such as human exfoliated deciduous teeth, apical papilla, periodontal ligament and dental follicle tissue. This review will overview the information about isolation, cellular and molecular characterization and differentiation of DPSCs into various types of human cells and thus these cells have important applications in regenerative therapies for various diseases. This review will be most useful for postgraduate dental students as well as scientists working in the field of oral pathology and oral medicine.

Polymeric vs hydroxyapatite-based scaffolds on dental pulp stem cell proliferation and differentiation

AIM: To evaluate adhesion, proliferation and differentiation of human dental pulp stem cells(h DPSCs) on four commercially available scaffold biomaterials. METHODS: hD PSCs were isolated from human dental pulp tissues of extracted wisdom teeth and established in stem cell growth medium. h DPSCs at passage 3-5 were seeded on four commercially available scaffold biomaterials, SureO ss(Allograft), Cerabone(Xenograft), PLLA(Synthetic), and OSTEON Ⅱ Collagen(Composite), for 7 and 14 d in osteogenic medium. Cell adhesion and morphology to the scaffolds were evaluated by scanning electron microscopy(SEM). Cell proliferation and differentiation into osteogenic lineage were evaluated using DNA counting and alkaline phosphatase(ALP) activity assay, respectively. RESULTS: All scaffold biomaterials except Sure Oss(Allograft) supported h DPSC adhesion, proliferation and differentiation. hD PSCs seeded on PLLA(Synthetic) scaffold showed the highest cell proliferation and attachment as indicated with both SEM and DNA counting assay. Evaluating the osteogenic differentiation capability of hD PSCs on different scaffold biomaterials with ALP activity assay showed high level of ALP activity on cells cultured on PLLA(Synthetic) and OSTEON ⅡCollagen(Composite) scaffolds. SEM micrographs also showed that in the presence of Cerabone(Xenograft) and OSTEON Ⅱ Collagen(Composite) scaffolds, the h DPSCs demonstrated the fibroblastic phenotype with several cytoplasmic extension, while the cells on PLLA scaffold showed the osteoblastic-like morphology, round-like shape. CONCLUSION: PLLA scaffold supports adhesion, proliferation and osteogenic differentiation of hD PSCs. Hence, it may be useful in combination with hD PSCs for cell-based reconstructive therapy.

Regenerative medicine using dental pulp stem cells for liver diseases

Acute liver failure is a refractory disease and its pro-gnosis, if not treated using liver transplantation, is extremely poor. It is a good candidate for regenerative medicine, where stem cell-based therapies play a central role. Mesenchymal stem cells(MSCs) are known to differentiate into multiple cell lineages including hepatocytes. Autologous cell transplant without any foreign gene induction is feasible using MSCs, thereby avoiding possible risks of tumorigenesis and immune rejection. Dental pulp also contains an MSC population that differentiates into hepatocytes. A point worthy of special mention is that dental pulp can be obtained from deciduous teeth during childhood and can be subsequently harvested when necessary after deposition in a tooth bank. MSCs have not only a regenerative capacity but also act in an anti--inflammatory manner via paracrine mechanisms. Promising efficacies and difficulties with the use of MSC derived from teeth are summarized in this review.

Human dental pulp stem cell is a promising autologous seed cell for bone tissue engineering

Background The seed cell is a core problem in bone tissue engineering research. Recent research indicates that human dental pulp stem cells （hDPSCs） can differentiate into osteoblasts in vitro, which suggests that they may become a new kind of seed cells for bone tissue engineering. The aim of this study was to evaluate the osteogenic differentiation of hDPSCs in vitro and bone-like tissue formation when transplanted with three-dimensional gelatin scaffolds in vivo, and hDPSCs may become appropriate seed cells for bone tissue engineering. Methods We have utilized enzymatic digestion to obtain hDPSCs from dental pulp tissue extracted during orthodontic treatment. After culturing and expansion to three passages, the cells were seeded in 6-well plates or on three-dimensional gelatin scaffolds and cultured in osteogenic medium. After 14 days in culture, the three-dimensional gelatin scaffolds were implanted subcutaneously in nude mice for 4 weeks. In 6-well plate culture, osteogenesis was assessed by alkaline phosphatase staining, Von Kossa staining, and reverse transcription-polymerase chain reaction （RT-PCR） analysis of the osteogenesis-specific genes type I collagen （COL I）, bone sialoprotein （BSP）, osteocalcin （OCN）, RUNX2, and osterix （OSX）. In three-dimensional gelatin scaffold culture, X-rays, hematoxylin/eosin staining, and immunohistochemical staining were used to examine bone formation. Results In vitro studies revealed that hDPSCs do possess osteogenic differentiation potential. In vivo studies revealed that hDPSCs seeded on gelatin scaffolds can form bone structures in heterotopic sites of nude mice. Conclusions These findings suggested that hDPSCs may be valuable as seed cells for bone tissue engineering. As a special stem cell source, hDPSCs may blaze a new path for bone tissue engineering.

Neural crest derived stem cells from dental pulp and tooth-associated stem cells for peripheral nerve regeneration

The peripheral nerve injuries,representing some of the most common types of traumatic lesions affecting the nervous system,are highly invalidating for the patients besides being a huge social burden.Although peripheral nervous system owns a higher regenerative capacity than does central nervous system,mostly depending on Schwann cells intervention in injury repair,several factors determine the extent of functional outcome after healing.Based on the injury type,different therapeutic approaches have been investigated so far.Nerve grafting and Schwann cell transplantation have represented the gold standard treatment for peripheral nerve injuries,however these approaches own limitations,such as scarce donor nerve availability and donor site morbidity.Cell based therapies might provide a suitable tool for peripheral nerve regeneration,in fact,the ability of different stem cell types to differentiate towards Schwann cells in combination with the use of different scaffolds have been widely investigated in animal models of peripheral nerve injuries in the last decade.Dental pulp is a promising cell source for regenerative medicine,because of the ease of isolation procedures,stem cell proliferation and multipotency abilities,which are due to the embryological origin from neural crest.In this article we review the literature concerning the application of tooth derived stem cell populations combined with different conduits to peripheral nerve injuries animal models,highlighting their regenerative contribution exerted through either glial differentiation and neuroprotective/neurotrophic effects on the host tissue.

Dental pulp stem cells and BonelikeVR for bone regeneration in ovine model

Development of synthetic bone substitutes has arisen as a major research interest in the need to find an alternative to autologous bone grafts.Using an ovine model,the present pre-clinical study presents a synthetic bone graft(BonelikeVR)in combination with a cellular system as an alternative for the regeneration of non-critical defects.The association of biomaterials and cell-based therapies is a promising strategy for bone tissue engineering.Mesenchymal stem cells(MSCs)from human dental pulp have demonstrated both in vitro and in vivo to interact with diverse biomaterial systems and promote mineral deposition,aiming at the reconstruction of osseous defects.Moreover,these cells can be found and isolated from many species.Non-critical bone defects were treated with BonelikeVR with or without MSCs obtained from the human dental pulp.Results showed that BonelikeVR and MSCs treated defects showed improved bone regeneration compared with the defects treated with BonelikeVR alone.Also,it was observed that the biomaterial matrix was reabsorbed and gradually replaced by new bone during the healing process.We therefore propose this combination as an efficient binomial strategy that promotes bone growth and vascularization in non-critical bone defects.

Dental stem cell-conditioned medium for tissue regeneration: Optimization of production and storage

BACKGROUND Mesenchymal stem cells(MSC)effects on tissue regeneration are mainly mediated by their secreted substances(secretome),inducing their paracrine activity.This Conditioned medium(CM),including soluble factors(proteins,nucleic acids,lipids)and extracellular vesicles is emerging as a potential alternative to cell therapy.However,the manufacturing of CM suffers from variable procedures and protocols leading to varying results between studies.Besides,there is no welldefined optimized procedure targeting specific applications in regenerative medicine.AIM To focus on conditioned medium produced from dental MSC(DMSC-CM),we reviewed the current parameters and manufacturing protocols,in order to propose a standardization and optimization of these manufacturing procedures.METHODS We have selected all publications investigating the effects of dental MSC secretome in in vitro and in vivo models of tissue regeneration,in accordance with the PRISMA guidelines.RESULTS A total of 351 results were identified.And based on the inclusion criteria described above,118 unique articles were included in the systematic review.DMSC-CM production was considered at three stages:before CM recovery(cell sources for CM),during CM production(culture conditions)and after production(CM treatment).CONCLUSION No clear consensus could be recovered as evidence-based methods,but we were able to describe the most commonly used protocols:donors under 30 years of age,dental pulp stem cells and exfoliated deciduous tooth stem cells with cell passage between 1 and 5,at a confluence of 70%to 80%.CM were often collected during 48 h,and stored at-80°C.It is important to point out that the preconditioning environment had a significant impact on DMSCCM content and efficiency.

Multidifferentiation potential of dental-derived stem cells

Tooth-related diseases and tooth loss are widespread and are a major public health issue.The loss of teeth can affect chewing,speech,appearance and even psychology.Therefore,the science of tooth regeneration has emerged,and attention has focused on tooth regeneration based on the principles of tooth development and stem cells combined with tissue engineering technology.As undifferentiated stem cells in normal tooth tissues,dental mesenchymal stem cells(DMSCs),which are a desirable source of autologous stem cells,play a significant role in tooth regeneration.Researchers hope to reconstruct the complete tooth tissues with normal functions and vascularization by utilizing the odontogenic differentiation potential of DMSCs.Moreover,DMSCs also have the ability to differentiate towards cells of other tissue types due to their multipotency.This review focuses on the multipotential capacity of DMSCs to differentiate into various tissues,such as bone,cartilage,tendon,vessels,neural tissues,muscle-like tissues,hepatic-like tissues,eye tissues and glands and the influence of various regulatory factors,such as non-coding RNAs,signaling pathways,inflammation,aging and exosomes,on the odontogenic/osteogenic differentiation of DMSCs in tooth regeneration.The application of DMSCs in regenerative medicine and tissue engineering will be improved if the differentiation characteristics of DMSCs can be fully utilized,and the factors that regulate their differentiation can be well controlled.

Comparative analysis of different feeder layers with 3T3 fibroblasts for culturing rabbits limbal stem cells

AIM： To explore the possibility of human umbilical cord mesenchymal stem cells（h UCMSCs）, human umbilical vein endothelial cells（h UVECs）, human dental pulp stem cells（h DPSCs） and human periodontal ligament stem cells（h PDLSCs） serving as feeder cells in co-culture systems for the cultivation of limbal stem cells.METHODS： Different feeder layers were cultured in Dulbecco＇s modified Eagle＇s medium（DMEM）/F12 and were treated with mitomycin C. Rabbits limbal stem cells（LSCs） were co-cultured on h UCMSCs, h UVECs, h DPSCs, h PDLSCs and NIH-3T3, and then comparative analysis were made between each group to see their respective colony-forming efficiency（CFE） assay and immunofluorescence（IPO13,CK3/12）.RESULTS： The efficiency of the four type cells in supporting the LSCs morphology and its cellular differentiation was similar to that of NIH-3T3 fibroblasts as demonstrated by the immunostaining properties analysis, with each group exhibiting a similar strong expression pattern of IPO13, but lacking CK3 and CK12 expression in terms of immunostaining. But h UCMSCs, h DPSCs and h PDLSCs feeder layers were superior in promoting colony formation potential of cells when compared to h UVECs and feedercell-free culture.CONCLUSION： hUCMSCs, hDPSCs and hPDLSCs can be a suitable alternative to conventional mouse NIH-3T3 feeder cells, so that risk of zoonotic infection can be diminished.

Tooth-derived stem cells: Update and perspectives

Tissue engineering is an emerging field of science that focuses on creating suitable conditions for the regeneration of tissues. The basic components for tissue engineering involve an interactive triad of scaffolds, signaling molecules, and cells. In this context,stem cells(SCs) present the characteristics of selfrenewal and differentiation capacity, which make them promising candidates for tissue engineering. Although they present some common markers, such as cluster of differentiation(CD)105, CD146 and STRO-1, SCs derived from various tissues have different patterns in relation to proliferation, clonogenicity, and differentiation abilities in vitro and in vivo. Tooth-derived tissues have been proposed as an accessible source to obtain SCs with limited morbidity, and various tooth-derived SCs(TDSCs) have been isolated and characterized, such as dental pulp SCs, SCs from human exfoliated deciduous teeth, periodontal ligament SCs, dental follicle progenitor cells, SCs from apical papilla, and periodontal ligament of deciduous teeth SCs. However, heterogeneity among these populations has been observed, and the best method to select the most appropriate TDSCs for regeneration approaches has not yet been established. The objective of this review is to outline the current knowledge concerning the various types of TDSCs, and discuss the perspectives for their use in regenerative approaches.

Dental pulp cell bank as a possible future source of individual hepatocytes

Mesenchymal stem cells(MSCs) as a source for regenerative medicine are now the subject of much clinical attention. There are high expectations due to their safety, low tumorigenic risk, and low ethical concerns. MSC therapy has been approved for acute graft-versus host diseases since 2015. Tooth-derived MSCs are known to have a great potential in their proliferation and differentiation capacities, even when compared with bone-marrow-derived MSCs. In particular, stem cells from human exfoliated deciduous teeth(SHEDs) are the best candidates for personal cell banking(dental pulp cell bank), because they can be obtained less invasively in the natural process of individual growth. SHEDs are known to differentiate into hepatocytes. There have been several studies showing the effectiveness of SHEDs on the treatment of liver failure in animal models. They may exert their effects either by repopulation of cells in injured liver or by paracrine mechanisms due to their immuneregulatory functions. Moreover, it may be possible to use each individuals' dental pulp cells as a future source of tailor-made differentiated hepatocytes in the context of a bioartificial liver or liver-on-a-chip to screen for drug toxicity.

Adult stem cell-based apexogenesis

Generally, the dental pulp needs to be removed when it is infected, and root canal therapy(RCT) is usually required in which infected dental pulp is replaced with inorganic materials(paste and gutta percha). This treatment approach ultimately brings about a dead tooth. However, pulp vitality is extremely important to the tooth itself, since it provides nutrition and acts as a biosensor to detect the potential pathogenic stimuli. Despite the reported clinical success rate, RCT-treated teeth are destined to be devitalized, brittle and susceptible to postoperative fracture. Recently, the advances and achievements in the field of stem cell biology and regenerative medicine have inspired novel biological approaches to apexogenesis in young patients suffer-ing from pulpitis or periapical periodontitis. This review mainly focuses on the benchtop and clinical regeneration of root apex mediated by adult stem cells. Moreover, current strategies for infected pulp therapy are also discussed here.

牙源性间充质干细胞外泌体在牙髓再生中的作用机制

牙髓再生是一种基于组织工程治疗牙髓坏死的新策略,应用种子细胞结合支架和生长因子,实现牙本质、血管和神经的新生。外泌体是一类直径约为30~150 nm的细胞外囊泡,在调控细胞间信息和物质传递中发挥重要作用。2016年以来,牙源性间充质干细胞分泌的外泌体因其在牙髓组织再生领域展现出的巨大潜力而备受瞩目。本文介绍了牙源性间充质干细胞来源外泌体的种类和培养环境,并对牙源性间充质干细胞外泌体调控细胞成牙本质向分化、血管生成、神经再生和成骨向分化的作用和机制作一综述。