Effects of morphogen and scaffold porogen on the differentiation of dental pulp stem cells.
ABSTRACT Dental pulp tissue engineering is an emerging field that can potentially have a major impact on oral health. However, the source of morphogens required for stem cell differentiation into odontoblasts and the scaffold characteristics that are more conducive to odontoblastic differentiation are still unclear. This study investigated the effect of dentin and scaffold porogen on the differentiation of human dental pulp stem cells (DPSCs) into odontoblasts.
Poly-L-lactic acid (PLLA) scaffolds were prepared in pulp chambers of extracted human third molars using salt crystals or gelatin spheres as porogen. DPSCs seeded in tooth slice/scaffolds or control scaffolds (without tooth slice) were either cultured in vitro or implanted subcutaneously in immunodefficient mice.
DPSCs seeded in tooth slice/scaffolds but not in control scaffolds expressed putative odontoblastic markers (DMP-1, DSPP, and MEPE) in vitro and in vivo. DPSCs seeded in tooth/slice scaffolds presented lower proliferation rates than in control scaffolds between 7 and 21 days (p < 0.05). DPSCs seeded in tooth slice/scaffolds and transplanted into mice generated a tissue with morphological characteristics similar to those of human dental pulps. Scaffolds generated with gelatin or salt porogen resulted in similar DPSC proliferation. The porogen type had a relatively modest impact on the expression of the markers of odontoblastic differentiation.
Collectively, this work shows that dentin-related morphogens are important for the differentiation of DPSC into odontoblasts and for the engineering of dental pulp-like tissues and suggest that environmental cues influence DPSC behavior and differentiation potential.
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ABSTRACT: Dentinal repair in the postnatal organism occurs through the activity of specialized cells, odontoblasts, that are thought to be maintained by an as yet undefined precursor population associated with pulp tissue. In this study, we isolated a clonogenic, rapidly proliferative population of cells from adult human dental pulp. These DPSCs were then compared with human bone marrow stromal cells (BMSCs), known precursors of osteoblasts. Although they share a similar immunophenotype in vitro, functional studies showed that DPSCs produced only sporadic, but densely calcified nodules, and did not form adipocytes, whereas BMSCs routinely calcified throughout the adherent cell layer with clusters of lipid-laden adipocytes. When DPSCs were transplanted into immunocompromised mice, they generated a dentin-like structure lined with human odontoblast-like cells that surrounded a pulp-like interstitial tissue. In contrast, BMSCs formed lamellar bone containing osteocytes and surface-lining osteoblasts, surrounding a fibrous vascular tissue with active hematopoiesis and adipocytes. This study isolates postnatal human DPSCs that have the ability to form a dentin/pulp-like complex.Proceedings of the National Academy of Sciences 01/2001; 97(25):13625-30. · 9.74 Impact Factor
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ABSTRACT: Teeth develop from reciprocal interactions between mesenchyme cells and epithelium, where the epithelium provides the instructive information for initiation. Based on these initial tissue interactions, we have replaced the mesenchyme cells with mesenchyme created by aggregation of cultured non-dental stem cells in mice. Recombinations between non-dental cell-derived mesenchyme and embryonic oral epithelium stimulate an odontogenic response in the stem cells. Embryonic stem cells, neural stem cells, and adult bone-marrow-derived cells all responded by expressing odontogenic genes. Transfer of recombinations into adult renal capsules resulted in the development of tooth structures and associated bone. Moreover, transfer of embryonic tooth primordia into the adult jaw resulted in development of tooth structures, showing that an embryonic primordium can develop in its adult environment. These results thus provide a significant advance toward the creation of artificial embryonic tooth primordia from cultured cells that can be used to replace missing teeth following transplantation into the adult mouth.Journal of Dental Research 08/2004; 83(7):518-22. · 3.83 Impact Factor
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ABSTRACT: Tooth loss adversely affects not only mouth functions but also the esthetics of one's face. To repair these defects, current treatment methods mainly depend on nonbiological materials or artificial implants that also can, sometimes, reduce the quality of life because of their limited physiological function, or elicit an immunological rejection. Theoretically, a biological tooth (bio-tooth) that is made from the patient's own cells and grows in its intended location should be the best choice for treating tooth loss, although such bioengineered teeth have been nothing more than a dream for many centuries. Recently, significant advances in the fields of tissue engineering, stem cell biology, developmental biology, molecular genetics, and bionics have brought us close to the realization of a bio-tooth. However, issues involving in the reconstruction of a bio-tooth regarding the shape determination, size control, availability of dental epithelium, directional growth and eruption, and graft rejection in the jaws remain to be resolved. Here, this review outlines the current approaches toward the tooth regeneration, and focuses on several key challenges that must be met in the making of a bio-tooth.Tissue Engineering Part B Reviews 10/2008; 14(3):307-19. · 4.64 Impact Factor