Bone marrow and teeth contain mesenchymal stem cells (MSCs) that could be used for cell-based regenerative therapies. MSCs from these two tissues represent heterogeneous cell populations with varying degrees of lineage commitment. Although human bone marrow stem cells (hBMSCs) and human dental pulp stem cells (hDPSCs) have been extensively studied, it is not yet fully defined if their adipogenic potential differs. Therefore, in this study, we compared the in vitro adipogenic differentiation potential of hDPSCs and hBMSCs. Both cell populations were cultured in adipogenic differentiation media, followed by specific lipid droplet staining to visualise cytodifferentiation. The in vitro differentiation assays were complemented with the expression of specific genes for adipogenesis and osteogenesis–dentinogenesis, as well as for genes involved in the Wnt and Notch signalling pathways. Our findings showed that hBMSCs formed adipocytes containing numerous and large lipid vesicles. In contrast to hBMSCs, hDPSCs did not acquire the typical adipocyte morphology and formed fewer lipid droplets of small size. Regarding the gene expression, cultured hBMSCs upregulated the expression of adipogenic-specific genes (e.g., PPARγ2, LPL, ADIPONECTIN). Furthermore, in these cells most Wnt pathway genes were downregulated, while the expression of NOTCH pathway genes (e.g., NOTCH1, NOTCH3, JAGGED1, HES5, HEY2) was upregulated. hDPSCs retained their osteogenic/dentinogenic molecular profile (e.g., RUNX2, ALP, COLIA1) and upregulated the WNT-specific genes but not the NOTCH pathway genes. Taken together, our in vitro findings demonstrate that hDPSCs are not entirely committed to the adipogenic fate, in contrast to the hBMSCs, which are more effective to fully differentiate into adipocytes.

Odontogenesis, the intricate process of tooth development, involves complex interactions between oral ectoderm epithelial cells and ectomesenchymal cells derived from the cephalic neural crest, regulated by major signaling pathways. Dental developmental anomalies provide valuable insights for the clinical diagnosis of rare diseases. More than 30% of patients with rare diseases who undergo molecular analysis suffer from diagnostic errancy. In the search for up-to-date technologies and methods to study the pathophysiology of new candidate genetic variants, causing tooth mineralized tissue anomalies, we have developed an original model of tooth organoids with human or mouse cell lines of ameloblast-like cells and odontoblasts derived from the pulp. This in vitro 3D cellular model reproducing the two main compartments of the bell stage of tooth development between ameloblasts and odontoblasts, specific to enamel and dentin morphogenesis, respectively, mimics the epithelial–mesenchymal interactions during the dental bell stage of tooth morphogenesis and will facilitate the study of enamel and dentin genetic anomalies, allowing the functional validation of newly identified mutations (variants of uncertain significance or new candidate genes). Impact Statement: We have developed and characterized innovative 3D bilayer organotypic cellular models with ameloblast-like cells and odontoblast-like cells (both murine and human) reproducing some of the interactions during the bell stage of odontogenesis. This is a first model of such type, considering human lineages and not only primary dental cells, with high reproducibility, and including recently developed polymeric poly-(lactic-coglycolic acid) microscaffolds for increasing cell survival and favoring cell differentiation. This work opens new perspectives to the study of tooth morphogenesis in vitro and associated genetic disorders, either for fundamental studies or for the development of new diagnostic tools of structure for dental rare diseases, such as amelogenesis imperfecta or dentinogenesis imperfecta.

Bacterium-triggered carious lesions implicate dental hard tissue destruction and the simultaneous initiation of regenerative events comprising dental stem cell activation. Streptococcus mutans (S. mutans) is a prominent pathogen of the oral cavity and the principal cause of caries. S. mutans generates complex products involved in interbacterial interactions, including Mutanobactin-D (Mub-D), which belongs to a group of non-ribosomal cyclic lipopeptides. In the present study, we aimed to analyse the potential role of the synthetic Mub-D peptide in cell populations involved in tissue regenerative processes. To this end, we assessed the in vitro effects of Mub-D in human dental pulp stem cells (hDPSCs) and human bone marrow stem cells (hBMSCs). Our data demonstrated a concentration-dependent effect of Mub-D on their viability and a significant increase in their proliferation and osteogenic/odontogenic differentiation. These events were associated with specific changes in gene expression, where CCDN-1, RUNX-2, OSX, OCN, DMP-1, DSPP, and BMP-2 genes were upregulated. The ability of Mub-D to modulate the osteogenic/odontogenic differentiation of both hDPSCs and hBMSCs and considerably enhance mineralisation in a controlled and concentration-dependent manner opens new perspectives for stem cell-based regenerative approaches in the clinics.

Current in vitro tissue models struggle to recapitulate the structural, vascular, and mechanical complexity of human tissues, limiting their physiological relevance for disease modelling and preclinical testing. Self-organising three-dimensional cultures such as spheroids and organoids capture key aspects of cellular organisation and differentiation, but they commonly lack controlled geometry, perfusable vasculature, and reproducible mechanical microenvironments. Conversely, biofabrication strategies, such as three-dimensional (3D) bioprinting and organ-on-chip (OoC) microfluidic devices, offer spatial control, integrated perfusion, and dynamic mechanical stimulation, yet often fall short in recapitulating the full cellular diversity and self-organisation of native tissues. Notably, emerging hybrid approaches that embed self-organising biological units (e.g., organoids and spheroids) into engineered scaffolds or microfluidic platforms combine biological relevance, architectural fidelity, and functional control. Advances in bioink chemistry, sacrificial-printing vascularisation, and chip–organoid interfaces now enable perfusable, multicompartment tissues suitable for disease modelling and preclinical testing. This review highlights the most recent (2020–2025) progress in organoid vascularisation, bioprinting strategies for prevascularised constructs, and OoC integration, outlining remaining challenges and emphasising priorities for next-generation hybrid cellular and tissue models.

Biodegradable polymeric scaffolds incorporating bioactive mineral phases are a promising approach for dentin-pulp tissue engineering. Although poly(lactic-co-glycolic acid) (PLGA) microparticles have been widely used as scaffolds due to their biocompatibility and tunable degradation profile, their inherent bioactivity is limited. Furthermore, fluorapatite (FAP), a fluoride-substituted apatite ceramic, exhibits enhanced chemical stability and mineral-related properties that may be useful for regenerative biomaterial design. In this study, we investigated the effect of nano-FAP functionalization on the physicochemical properties of porous PLGA microscaffolds and their interaction with human dental pulp stem cells (hDPSCs). Porous PLGA microscaffolds were fabricated using a double-emulsion solvent evaporation method and subsequently functionalized with FAP suspensions ranging from 0.1 to 5 mg/mL (0.01–0.5% w/v). The scaffolds were evaluated using scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), electrical conductivity measurements, cell viability assays, and immunofluorescence. Lower and intermediate FAP concentrations-maintained surface pore accessibility and supported hDPSC viability, whereas the highest concentration (5 mg/mL; 0.5% w/v) reduced visible surface pore size and showed less favorable cellular responses. The 2.5 mg/mL (0.25% w/v) FAP condition provided the most favorable overall balance among the evaluated physicochemical and biological parameters. These preliminary in vitro findings support further investigation of FAP-functionalized PLGA microscaffolds in advanced three-dimensional and in vivo models.

Les mécanismes impliqués dans l’initiation et le développement des parodontites, ainsi que la dissémination des parodontopathogènes via la circulation systémique et ses effets au niveau vasculaire, restent peu connus. L'infection chronique a été décrite comme un mécanisme potentiel impliqué dans l'aggravation de l'athérothrombose. A l’heure actuelle, le rôle joué par Porphyromonas gingivalis (P.gingivalis) est considéré comme majeur dans les phénomènes associés, tels que sa capacité à perturber la barrière épithéliale ainsi que l’endothélium vasculaire, l’induction d’une réponse inflammatoire soutenue contribuant à la destruction tissulaire. Dans ces travaux de thèse, nous avons évalué les effets de P.gingivalis sur l’apoptose et l’inflammation des cellules épithéliales (GEC), fibroblastiques (FB) et dans un modèle 3D de microtissus (MT), ainsi que dans des cellules endothéliales (EC). Finalement, nous avons évalué son rôle dans la réponse inflammatoire liée à la signalisation via les TLR-2 et TLR-4 et cinq protéines adaptatrices contenant le domaine du récepteur Toll/interleukine-1 (TIR). Nous avons mis en évidence que P.gingivalis est capable d'activer l'inflammation et la réponse du système immunitaire entraînant la destruction du parodonte en modulant différentiellement des processus biologiques primordiaux tels que l'apoptose (modulation de l’apoptosome Apaf-1 et son inhibiteur XIAP), le cycle cellulaire (P53, P21, CDK4), l'inflammation (modulation des TLR-2, TLR-4 et ses adaptateurs MAL et TRAM et des protéines inflammatoires telles que TNF-α), lui permettant d’échapper au système immunitaire, de contribuer à la destruction parodontale et sa dissémination systémique et d’exercer des effets sur l’endothélium. La mise en évidence de nouveaux mécanismes ou de nouvelles cibles cellulaires affectées par ce pathogène pourrons nous permettre de développer de nouvelles stratégies thérapeutiques.