Dental Pulp Research Articles

TRAUMATISMOS DENTAIS NA INFÂNCIA E SUAS IMPLICAÇÕES NA POLPA: REVISÃO DE LITERATURA

Childhood dental trauma is common, especially in the 2-7 age group, and affects the upper central incisors more due to their exposure in impact situations. When the trauma involves the dental pulp, the treatment is to preserve the vitality of the tooth, with pulp capping and pulpotomy procedures being the most recommended. Currently, there has been a shift from invasive practices to conservative techniques in order to minimize long-term damage and improve the child's prognosis. The International Association of Dental Traumatology (IADT) guidelines contribute to this conservative approach, affirming the importance of immediate treatment and follow-up to avoid complications. The objective of this study is to demonstrate the implications of dental trauma in childhood, as well as how the pulp reacts to trauma. This literature review is based on articles published between 2014 and 2024, searched in the Scielo, Pubmed, Google Scholar and Periódico Capes databases. It was possible to conclude that, when subjected to trauma, the affected tooth may present some pulp responses, with pulp necrosis was the most frequent alteration.

Comprehensive Evaluation of Decellularized Dental Pulp as a New Biomaterial for Regeneration of the Pulp-Dentin Complex

Objective: To develop a detergent-enzymatic method and evaluate the quality of a decellularized pulp scaffold for regenerative endodontics.Materials and methods: Biomaterial and mesenchymal stem cells (MSCs) were derived from dental pulp that was obtained following third molar extraction indicated for orthodontic reasons in patients aged 14-18 years. The detergent-enzymatic method enabled to obtain a decellularized scaffold from pulp samples. The proliferative activity and viability of dental pulp-derived MSCs were assessed using trypan blue staining and XTT assay. To assess tissue response, Wistar rats underwent subcutaneous implantation of native and decellularized dental pulp. Explanted samples were stained with hematoxylin-eosin on days 7 and 14.Results: The detergent-enzymatic treatment of the dental pulp demonstrated the absence of nuclear material, whereas the histoarchitecture of the dental pulp was disturbed. The DNA content in the sample of the decellularized scaffold was 22.79 ± 2.1 ng/mg of tissue; the amount of DNA in the native sample was 78.5 ± 5.4 ng/mg of tissue. According to XTT assay results, no cytotoxicity of the decellularized scaffold against MSCs was found. Biopsy specimens of the rats with implanted decellularized dental pulp were characterized by no signs of inflammation.Conclusions: The study results will enable to create a biomaterial that can be the base of a tissue-engineered structure of the dental pulp and be used for the regeneration of the pulp-dentin complex.

Therapeutic potential of melatonin-pretreated human dental pulp stem cells (hDPSCs) in an animal model of spinal cord injury.

Dental pulp stem cells (DPSCs) show potential for treating neurodegenerative and traumatic diseases due to their neural crest origin. Melatonin (MT), an endogenous neurohormone with well-documented anti-inflammatory and antioxidant properties, has shown promising results with MSCs in terms of engraftment, proliferation, and neuronal differentiation in animal SCI models. However, the effects of melatonin preconditioning on human dental pulp stem cells (hDPSCs) for SCI treatment remain unclear. This study investigates the impact of melatonin preconditioning on hDPSCs engraftment, neural differentiation, and neurological function in rats with SCI. Forty-two male Sprague-Dawley rats were divided into six groups: Control, Sham, Model, Vehicle, Lesion Treatment A(SCI + hDPSCs), and Lesion Treatment B(SCI + MT-hDPSCs). After obtaining hDPSCs, stem cells were evaluated using flow cytometry. Cell viability was assessed using the MTT assay. SCI was induced in the Model, Vehicle, Lesion Treatment A, and Lesion Treatment B groups. The Lesion Treatment A and B groups received hDPSCs and hDPSCs pretreated with melatonin, respectively, 1 week after SCI, while the Vehicle group received only an intravenous injection of DMEM to simulate treatment. The other groups were used for behavioral testing. Immunohistochemistry (IHC) was employed to assess hDPSCs engraftment and differentiation at the SCI site. Motor function across the six groups was evaluated using the Basso, Beattie, and Bresnahan (BBB) score. Histological studies and cell counts confirmed hDPSCs implantation at the injury site, with a significantly higher presence in the MT-hDPSCs compared to hDPSCs(p < 0.01). IHC revealed that hDPSCs and MT-hDPSCs differentiated into neurons and astrocytes, with greater differentiation observed in the MT-hDPSCs compared to the hDPSCs (p < 0.01 and p < 0.05, respectively). Functional improvement was noted in both SCI + hDPSCs and SCI + MT-hDPSCs groups compared to SCI and Vehicle groups from Week 4 onward (p < 0.001). Significant differences were also observed between the SCI + hDPSCs and SCI + MT-hDPSCs groups starting from Week 7 (p < 0.01). Preconditioning hDPSCs with melatonin enhances engraftment, neuronal differentiation, and greater performance improvement compared to hDPSCs alone in the SCI animal model.

B2M or CIITA knockdown decreased the alloimmune response of dental pulp stem cells: an in vitro study.

Dental pulp stem cells (DPSCs) have acquired noteworthy attention for their application in treating ischemic diseases and facilitating tissue regeneration. However, the host's immune response following allogenic DPSC transplantation often handicaps the long-term survival of transplanted cells, thereby limiting the application of DPSCs in cell therapy. This study aims to investigate whether genetic modification can alleviate the immunogenicity of DPSCs. Beta 2-microglobulin (B2M) and the class II histocompatibility complex transactivator (CIITA) were individually knocked down in DPSCs by lentiviral particles encoding short hairpin (sh) RNAs. The self-renewal capacity and pluripotency of DPSCs-shB2M (B2M silenced DPSCs) and DPSCs-shCIITA (CIITA silenced DPSCs) were evaluated by CCK8 and differentiation assays including osteogenesis, adipogenesis, and neurogenesis. The expression of HLA-I and HLA-II in DPSCs-shB2M and DPSCs-shCIITA after IFN-γ treatment were analyzed by western blotting, immunofluorescence, and flow cytometry. The function of genetically modified cells was assessed by leukocyte-mediated cytotoxicity and T-cell proliferation assays. Western blotting, immunofluorescence, and flow cytometry revealed that DPSCs-shB2M and DPSCs-shCIITA exhibited impaired IFN-γ inducible HLA-I and HLA-II expression. There were no significant differences in the self-renewal capacity and pluripotency among DPSCs-shB2M, DPSCs-shCIITA, and control groups (p > 0.05). Lower leukocyte-mediated cytotoxicity and higher cell survival rates were found in DPSCs-shB2M and DPSCs-shCIITA groups compared to the control (p < 0.05). T cell proliferation was significantly inhibited in both DPSCs-shB2M and DPSCs-shCIITA groups (p < 0.05). Genetic knockdown of B2M or CIITA in DPSCs substantially reduced their immunogenicity without compromising their stemness, thereby broadening the clinical application of DPSCs in cell therapy and tissue regeneration.

Stem Cells: Innovations, Applications, and Future Directions

ABSTRACT Stem cells offer great promise in dentistry by regenerating critical oral tissues. Derived from sources such as dental pulp, periodontal ligament, and dental follicle, these cells can be pluripotent or multipotent and are capable of differentiating into various cell types, including odontoblasts and osteoblasts. This regenerative potential could transform treatments for dental conditions like periodontal disease and pulpitis. Advancing this field requires understanding stem cell differentiation and exploring tissue engineering and biomaterial scaffolds. Despite the potential, evolving legal and ethical issues shape the integration of these innovations. Research in dental stem cells represents a significant advance in regenerative medicine, promising to enhance dental treatments and patient care.

Dental pulp stem cell‑derived extracellular vesicles loaded with hydrogels promote osteogenesis in rats with alveolar bone defects.

Alveolar bone defects caused by inflammation, trauma and tumors adversely affect periodontal health, causing tooth loosening or dentition defects, thus affecting denture or implant repair. Advancements in tissue engineering technology and stem cell biology have significantly improved the regenerative reconstruction of alveolar bone defects. The multiple trophic activities of extracellular vesicles (EVs) produced by mesenchymal stem cells play important roles in exerting their therapeutic effects. Several studies have reported the role of dental pulp stem cells (DPSCs) in bone regeneration, but the regenerative effects of DPSC‑EVs on alveolar bone defects are unclear. In the present study, the osteogenic effects of DPSC‑EVs on Hertwig's epithelial root sheath (HERS) cells in vitro and their osteoinductive effects in an alveolar bone defect rat model were investigated. The results showed that DPSC‑EVs significantly promoted the expression of osteogenic genes, such as runt‑related transcription factor 2 and alkaline phosphatase, and increased the osteogenic differentiation capability of HERS. These findings suggested that transforming growth factor β1 inhibition decreased DPSC‑EV‑induced Smad, MAPK and ERK phosphorylation in HERS. In vivo, DPSC‑EV‑loaded hydrogels were transplanted into the alveolar sockets of Sprague‑Dawley rats and observed for eight weeks. The new bone grew concentrically in the DPSC‑EV or DPSC‑EV‑loaded hydrogel group, with greater bone mass than that in the control group, and the bone volume/total volume increased notably. The results confirmed the osteogenic and osteoinductive effects of DPSC‑EVs and DPSC‑Exo‑loaded hydrogels on alveolar bone defects. Due to their low immunogenicity, high stability, good biocompatibility and osteogenic propensity, DPSC‑EV‑loaded hydrogels are a safe cell‑free therapeutic approach for defective alveolar bone regeneration.

Divergent Proteomic Profiles and Uptake Mechanisms of Exosomes Derived from Human Dental Pulp Stem Cells, Endothelial Cells, and Fibroblasts.

Effective intercellular communication is crucial for tissue repair and regeneration, with exosomes playing a key role in mediating these processes by transferring proteins, lipids, and nucleic acids between cells. This study explored the mechanisms underlying the uptake of exosomes derived from human dental pulp stem cells (hDPSCs), human umbilical vein endothelial cells (HUVECs), and human fibroblasts (HFBs). Our findings revealed that hDPSCs exhibited the greatest capacity for exosome uptake across all three cell types. Moreover, exosomes originating from hDPSCs were also taken up in the highest amounts by all three cell types. Proteomic analysis uncovered significant differences in protein expression among exosomes from these different cell types, particularly in proteins related to endocytosis. Clathrin-dependent endocytosis emerged as the primary pathway for exosome uptake in hDPSCs and HUVECs, while HFBs appeared to use a different mechanism. Additionally, proteins such as fibronectin and tetraspanins were found to be highly expressed in hDPSC-derived exosomes, suggesting their potential involvement in exosome-cell interactions. This study offers new insights into exosome uptake mechanisms and highlights the potential of exosomes in advancing tissue engineering and regenerative medicine.

Harmine promotes odontoblastic differentiation of dental pulp stem cells

Introduction Dental pulp stem cells (DPSCs) have the potential to differentiate into various types of tissues including tooth, adipose, cartilage, muscle, nerve, and also possess regenerative properties. Harmine, a beta-carboline alkaloid, has been shown to have antitumor activities and promote bone formation through the differentiation of osteoblasts. The aim of this study was to investigate the effect of harmine on the differentiation of DPSCs into odontoblast cells. Materials and methods DPSCs were obtained from Iran’s National Genetic Reserve Center and cultured under standard stem cell culture conditions. The cells were differentiated in culture medium with and without harmine, and cell viability was evaluated using MTT assay at different harmine concentrations. Moreover, differentiation of cells was measured using Alizarin Red staining, and the expression of Runx2, DSPP, and DMP1 genes was evaluated using western blotting and real-time PCR. Results Harmine increased the survival rate of DPSCs in a time-­dependent manner, but higher doses (above 80 μM) had a toxic effect. On day 14, Alizarin Red staining showed increased differentiation of odontoblasts in the harmine-treated groups compared to the untreated groups. Furthermore, harmine increased the expression of Runx2, DSPP, and DMP1 genes and proteins. Conclusion These findings suggest that harmine has a significant impact on the differentiation and proliferation of odontoblasts in DPSCs, likely due to its various properties and role in healing various diseases. Therefore, harmine could serve as a potential therapeutic agent for promoting dental tissue regeneration using DPSCs.

Dental Pulp Stem Cell Conditioned Medium Enhance Osteoblastic Differentiation and Bone Regeneration.

Cell-free approaches, utilizing mesenchymal stem cell secretome, have promising prospects in various fields of regenerative medicine. In this study, we examined in vitro and in vivo the potential of dental pulp stem cell-conditioned medium (DPSC-CM) for bone regeneration. The secretome of undifferentiated stem cells from dental pulp were collected, and the effects of this DPSC-CM were assessed for osteodifferentiation of osteoblast-like cells (MG-63) and osteoblasts deriving from DPSC. Cell proliferation, alkaline phosphatase (ALP) activity, gene expression of Runt-related transcription factor 2 (Runx2), Bone Sialoprotein (BSP), Osteocalcin (OCN), and extracellular matrix mineralization were evaluated. The rat caudal vertebrae critical size defect model was to investigate the effect of DPSC-CM in vivo. Results showed that DPSC-CM induced cell growth, and increased ALP activity and the expression of key marker genes at an early stage of osteoblastic differentiation compared to control. A rat bone defect model was used to illustrate the effect of DPSC-CM in vivo. The bone density within the defects were improved using conditioned medium, even though there was no significant difference between the control and DPSC-CM groups. The analysis of DPSC-CM by human growth factor antibody array revealed the presence of several factors involved in osteogenesis. Taken together, these findings indicate that DPSC-CM is a promising therapeutic candidate for bone regenerative therapy, accelerating the maturation of osteoblastic cells. And even though safety and efficiency of DPSC-CM have to be confirmed in preclinical studies, these results represent a first step toward clinical application.

Ischemic Risks Induced by Larger Orthodontic Forces on Dental Pulp and Neuro-Vascular Bundle in Reduced Periodontium

Background/Objectives: There are few data about the ischemic risks induced by the large orthodontic forces during periodontal breakdown in dental pulp and neuro-vascular bundle (NVB) and none on the individual tissular stress distribution, despite their great importance for orthodontic treatment planning. Our aim was to assess, by a numerical analysis, the biomechanical behavior of dental pulp and the NVB during a simulated horizontal periodontal breakdown (1–8 mm), under 2–4 N of applied orthodontic forces and five movements (rotation, translation, tipping, intrusion, and extrusion). Additionally, the ischemic and degenerative-resorptive risks were assessed. Methods: The analysis involved 72 3D models of nine patients, totaling 720 simulations. The models were CBCT-based, having the second lower premolar and surrounding periodontium, and they suffered 1 mm of gradual horizontal periodontal breakdown (up to 8 mm loss). Results: Both forces displayed a similar qualitative stress distribution in all five movements, but with a quantitative increase (doubling of stress amounts for 4 N when compared with 2 N). The highest amounts of stress were displayed at 8 mm of periodontal loss, which is lower than the 16 KPa of the maximum hydrostatic pressure. The NVB stress was higher than the pulpal stress. Rotation was the most stressful, closely followed by tipping, intrusion, and extrusion. Conclusions: A total of 4 N of applied force seems to not induce any ischemic or degenerative-resorptive risks for healthy intact teeth, in up to 8 mm of periodontal breakdown. Intrusion and extrusion determined the highest visible tissular deformation in the NVB, with potential ischemic and resorptive-generative risks for previously traumatized/injured teeth (i.e., occlusal trauma). Rotation and translation (in particular) showed the highest coronal and radicular pulpal stress with potential ischemic and resorptive-generative risks for previously injured/traumatized dental pulp (i.e., direct-indirect pulp capping). It seems that 4 mm of periodontal breakdown could signal a clinical stress increase with potential ischemic and degenerative-resorptive risks for the previously traumatized/injured tissues.

Anti-Inflammatory Effects of Calcium Hydroxide Combined with Ellagic Acid as Pulp Capping Material: In Vivo Study.

Pulp capping is a pivotal treatment in dentistry aimed at preserving pulp vitality. While calcium hydroxide has long been considered the gold standard in pulp capping materials, its long-term use can induce chronic inflammation, ultimately leading to pulp necrosis and affecting human health. In this context, ellagic acid, a natural compound with potent anti-inflammatory properties, emerged as a promising adjunct to mitigate inflammation associated with calcium hydroxide application, thereby sustaining pulp vitality. This study aimed to investigate the inflammatory response by alterations in neutrophil, macrophage, lymphocyte, and tumor necrosis factor-α (TNF-α) expression following the treatment with a combination of calcium hydroxide and ellagic acid. Dental pulp perforation was made on 27 male Wistar rats on the upper first molar and then pulp capped with calcium hydroxide and ellagic acid. The pulp of the control positive group was capped with calcium hydroxide, and the control group was not capped. The teeth were then extracted after 1, 3, and 7 days posttreatment. The differences in the number of neutrophils, macrophages, lymphocytes, and TNF-α expression were analyzed using one-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) test. The treatment combination of calcium hydroxide and ellagic acid showed the lowest neutrophil number and TNF-α expression compared with the other groups (p < 0.05), while the macrophage and lymphocyte numbers were the highest compared with the other groups (p < 0.05). The combination of calcium hydroxide and ellagic acid as a pulp capping material exhibited a dual effect on the inflammatory response in dental pulp. These findings suggest that calcium hydroxide and ellagic acid modulate the inflammatory response in a complex manner, promoting a more controlled and potentially beneficial healing process.

Robotic-Assisted Endodontics: A Future Perspective

Endodontics, a branch of dentistry focused on the diagnosis and treatment of dental pulp and periapical diseases, is undergoing a technological renaissance. Robotic-assisted endodontics is at the forefront of this change, leveraging advanced technologies to improve procedural accuracy, efficiency, and patient comfort. This article explores the current applications of robotic technology in endodontics, discusses the advantages and challenges, and outlines potential future directions for this innovative approach, ultimately aiming to revolutionize dental care.

Systemic Statin Use and Pulp Chamber Calcification: A Pilot Retrospective Case Control Study Using Cone-Beam Computed Tomography.

This pilot retrospective case-control study questioned whether systemic statin use causes pulp calcification using cone-beam computed tomography images from the patients prescribed oral statins and comparing those of healthy individuals. CBCT scans of 54 patients, including 27 age- and sex-matched patients for the study and control groups, were analysed using Mimics Innovation Suite software. The study included patients using statins regularly for at least 1 year. Only intact teeth with opposing teeth were selected for the study group and matched with the control group. Dental crown and pulp chamber volumes were calculated and proportioned. The data were analysed with chi-square and Shapiro-Wilk tests to assess normal distribution, followed by Mann-Whitney U test if necessary. Statistical analysis showed no difference between the study and control groups (p = 0.505). Statin use duration did not cause statistically significant difference in terms of the reduction of pulp chamber volume (p = 0.141). Within the limitations of the study, systemic statin use did not cause dental pulp calcification. The results suggest, oral administration of the statin drugs is not an unfavourable condition for dental practice. Further studies with larger numbers of patients are needed to support this conclusion.

A clinical approach for no prep direct composite veneers with opaquer/ tint to reshape a smile: a case report

Dental aesthetic has a profound influence on both self-esteem and social interactions. Patients desire changes in their smiles, while dentists aim for the preservation of dental and adjacent structures, as well as durability. In this context, no-prep resin veneers emerge as a potential solution, as they allow for the preservation of the maximum amount of healthy dental structure, pulp integrity, and dental strength. Nevertheless, treating darkened substrates poses a challenge, and conservative options like composite resins have gained recognition as restorative materials due to their aesthetic qualities and ability to preserve healthy dental tissue. A protocol can help dentists, especially by describing the stages of making direct no-prep veneers, achieving better clinical success. This article presents a clinical step-by-step guide approach to fabricating light-cured composite prepless veneers, using opaque and tints to mask dark backgrounds, and preserving the dental substrate in a patient with multiple restorations, changes in color, and shape. Light-cured composite prepless veneers comply with the principles of biomimetics and offer advantages such as conservation of dental structures, versatility, one-session preparation, cost, mechanical properties, and excellent aesthetics, however, skill with this technique is required.

Dental Pulp Stem Cell Lysate-Based Hydrogel Improves Diabetic Wound Healing via the Regulation of Anti-Inflammatory Macrophages and Keratinocytes.

The prolonged existence of chronic wounds heightens the risk of patients experiencing chronic pain, necrosis, and amputation. Dental pulp stem cells (DPSCs) have garnered attention due to their potential immunomodulatory and tissue repair regenerative effects in the management of chronic wounds. However, stem-cell-based therapy faces challenges such as malignant differentiation, immune rejection, and long-term effectiveness. To overcome these challenges, we proposed a chronic wound therapy using a hydrogel derived from human-originated dental pulp stem cell lysate (DPSCL). Our data indicate that, with the degradation of the dental pulp stem cell lysate-based hydrogel (DPSCLH), the slowly released cell lysates recruit anti-inflammatory M2 macrophages and promote the proliferation, migration, and keratinization of HacaT cells. In addition, in vivo studies revealed that DPSCLH avoids immune rejection reactions and induces a long-term accumulation of endogenous M2 macrophages. In a mouse model of diabetic wounds, DPSCLH effectively modulates the inflammatory microenvironment around diabetic wounds, promotes the formation of the stratum corneum, and facilitates the healing of wounds, thus holding tremendous potential for the treatment of diabetic wounds.

In Vivo and In Vitro Response to a Regenerative Dental Scaffold.

As dental pulp contains the stem cells necessary for regeneration, the tooth should hold the intrinsic capacity for self-repair. A triphasic hybrid dental biocomposite (3HB) composed of biocompatible biopolymers to provide strength, antibacterial properties and protein-based cell support could provide a conducive microenvironment for the regeneration of dental structures. 3HB was incorporated into Mineral Trioxide Aggregate (ProRoot MTA) to construct a malleable injectable implant. Human tooth pulp cells (hDPCs) significantly increased proliferation in the presence of 3HB+MTA compared to 3HB or MTA alone. Cell viability decreased with MTA alone but increased with 3HB and 3HB+MTA. 3HB+MTA was implanted into the residual tooth of drilled Wistar rat M2 molars for up to 45 days. Stereological analysis from micro-CT images showed the volume of the tooth remaining. Histologically, regenerative pulpal architecture was seen invading 3HB. A continuous odontoblastic profile lined a deposit of dentin-like material suggesting reparative dentinogenesis. Overall, no infection or encapsulation was seen. Immunohistochemically, odontoblasts were seen along the margins of the wounded tooth undergoing repair. Mesenchymal cells (MSCs) were seen at the base of the drilled tooth and by 21 days had translocated into the implant itself. Cells stimulating remineralization were highly expressed in the tooth undergoing repair. CD146-positive MSCs were seen in the center of the implant, possibly stimulating remineralization. In conclusion, behavior of 3HB+ in vitro and in vivo provided a promising start as 3HB+MTA may serve as a viable regenerative scaffold for pulp regeneration; however, this should be further studied before clinical use can be considered.

Dental pulp mesenchymal stem cell (DPSCs)-derived soluble factors, produced under hypoxic conditions, support angiogenesis via endothelial cell activation and generation of M2-like macrophages

BackgroundCell therapy has emerged as a revolutionary tool to repair damaged tissues by restoration of an adequate vasculature. Dental Pulp stem cells (DPSC), due to their easy biological access, ex vivo properties, and ability to support angiogenesis have been largely explored in regenerative medicine.MethodsHere, we tested the capability of Dental Pulp Stem Cell-Conditioned medium (DPSC-CM), produced in normoxic (DPSC-CM Normox) or hypoxic (DPSC-CM Hypox) conditions, to support angiogenesis via their soluble factors. CMs were characterized by a secretome protein array, then used for in vivo and in vitro experiments. In in vivo experiments, DPSC-CMs were associated to an Ultimatrix sponge and injected in nude mice. After excision, Ultimatrix were assayed by immunohistochemistry, electron microscopy and flow cytometry, to evaluate the presence of endothelial, stromal, and immune cells.For in vitro procedures, DPSC-CMs were used on human umbilical-vein endothelial cells (HUVECs), to test their effects on cell adhesion, migration, tube formation, and on their capability to recruit human CD14+ monocytes.ResultsWe found that DPSC-CM Hypox exert stronger pro-angiogenic activities, compared with DPSC-CM Normox, by increasing the frequency of CD31+ endothelial cells, the number of vessels and hemoglobin content in the Ultimatrix sponges. We observed that Utimatrix sponges associated with DPSC-CM Hypox or DPSC-CM Normox shared similar capability to recruit CD45− stromal cells, CD45+ leukocytes, F4/80+ macrophages, CD80+ M1-macrophages and CD206+ M2-macropages. We also observed that DPSC-CM Hypox and DPSC-CM Normox have similar capabilities to support HUVEC adhesion, migration, induction of a pro-angiogenic gene signature and the generation of capillary-like structures, together with the ability to recruit human CD14+ monocytes.ConclusionsOur results provide evidence that DPSCs-CM, produced under hypoxic conditions, can be proposed as a tool able to support angiogenesis via macrophage polarization, suggesting its use to overcome the issues and restrictions associated with the use of staminal cells.

An Update on Emerging Regenerative Medicine Applications: The Use of Extracellular Vesicles and Exosomes for the Management of Chronic Pain.

Chronic pain affects nearly two billion people worldwide, surpassing heart disease, diabetes, and cancer in terms of economic costs. Lower back pain alone is the leading cause of years lived with disability worldwide. Despite limited treatment options, regenerative medicine, particularly extracellular vesicles (EVs) and exosomes, holds early promise for patients who have exhausted other treatment options. EVs, including exosomes, are nano-sized structures released by cells, facilitating cellular communication through bioactive molecule transfer, and offering potential regenerative properties to damaged tissues. Here, we review the potential of EVs and exosomes for the management of chronic pain. In osteoarthritis, various exosomes, such as those derived from synovial mesenchymal stem cells, human placental cells, dental pulp stem cells, and bone marrow-derived mesenchymal stem cells (MSCs), demonstrate the ability to reduce inflammation, promote tissue repair, and alleviate pain in animal models. In intervertebral disc disease, Wharton's jelly MSC-derived EVs enhance cell viability and reduce inflammation. In addition, various forms of exosomes have been shown to reduce signs of inflammation in neurons and alleviate pain in neuropathic conditions in animal models. Although clinical applications of EVs and exosomes are still in the early clinical stages, they offer immense potential in the future management of chronic pain conditions. Clinical trials are ongoing to explore their therapeutic potential further, and with more research the potential applicability of EVs and exosomes will be fully understood.

Microspheres of stem cells from human exfoliated deciduous teeth exhibit superior pulp regeneration capacity

ObjectivesEngineering spheroids to create three-dimensional (3D) cell cultures has gained increasing attention in recent years due to their potential advantages over traditional two-dimensional (2D) tissue culture methods. Stem cells derived from human exfoliated deciduous teeth (SHEDs) demonstrate significant potential for pulpal regeneration applications. Nevertheless, the feasibility of microsphere formation of SHEDs and its impact on pulpal regeneration remain unclear. MethodsIn this study, SHEDs were isolated, identified, and cultured in ultra-low attachment six-well plates to produce SHED microspheres. The biological properties of SHED microspheres were compared to those of traditional 2D culture using live-dead staining, Alizarin red staining, Oil-red O staining, scratch experiments, Immunofluorescence, Transmission electron microscopy scan, Western blotting, RNA sequencing, and a nude mice subcutaneous transplantation model. ResultsWe found SHED cells can form microspheres with a dense internal structure. SHED microspheres exhibited notable advantages over SHED cells in terms of biological properties, maintaining cell activity and enhancing cell differentiation, migration, and stemness in vitro. RNA-seq revealed that the SHED microspheres potentially influenced cell development, regulation of neurogenesis, skeletal system development, tissue morphogenesis singling pathway. In vivo, SHED microspheres promoted the generation of pulp tissue in dental pulp compared to traditional 2D culture. ConclusionsMicrosphereization of SHED through 3D cell culture enhances its pulp regeneration capacity, presenting a novel strategy for dental pulp regeneration and the clinical treatment of dental pulp diseases.

“Young-Mechanical Niche” biomimetic hydrogel promotes dental pulp regeneration through YAP-dependent mechanotransduction

Aging leads to the irreversible deterioration of the extracellular matrix (ECM), compromising cell self-renewal, differentiation, and tissue regeneration. However, the specific mechanisms by which age-related changes in ECM-mediated cell mechanical microenvironment impair regeneration remain elusive. Human dental pulps (hDPs) provide an ideal model to explore this issue due to their accessibility and distinct mechanical properties. In this study, we discovered that young hDPs exhibit higher stiffness and viscoelasticity (i.e., faster stress relaxation time) compared to aged hDPs. Leveraging these findings, we engineered three groups of biomimetic hydrogels recapitulating the native mechanical microenvironment of young and aged hDPs. Our results demonstrated that Y-Gel, which replicates the high stiffness and viscoelasticity of young hDPs, significantly enhances the proliferation and odontogenic differentiation of human dental pulp stem cells (hDPSCs) in vitro and promotes dental pulp regeneration in vivo more effectively than hydrogels mimicking either aged stiffness (AS-Gel) or aged viscoelasticity (AV-Gel) alone. Moreover, YAP-dependent mechanotransduction, particularly through the YAP/TEAD1/CTGF/Cyr61 signaling pathway, plays a critical role in mediating these regenerative effects, with stiffness emerging as a more dominant factor than viscoelasticity. This study provides new insights into the synergistic role of mechanical factors in regulating cell behavior and offers a promising strategy for optimizing mechanical microenvironment to enhance dental pulp regeneration and potentially other tissue regeneration applications, especially from the mechanomedicine perspective.