Mesenchymal stem/stromal cells (MSCs) are multipotent cells located in different areas of the human body. The oral cavity is considered a potential source of MSCs because they have been identified in several dental tissues (D-MSCs). Clinical trials in which cells from these sources were used have shown that they are effective and safe as treatments for tissue regeneration. Importantly, immunoregulatory capacity has been observed in all of these populations; however, this function may vary among the different types of MSCs. Since this property is of clinical interest for cell therapy protocols, it is relevant to analyze the differences in immunoregulatory capacity, as well as the mechanisms used by each type of MSC. Interestingly, D-MSCs are the most suitable source for regenerating mineralized tissues in the oral region. Furthermore, the clinical potential of D-MSCs is supported due to their adequate capacity for proliferation, migration, and differentiation. There is also evidence for their potential application in protocols against autoimmune diseases and other inflammatory conditions due to their immunosuppressive capacity. Therefore, in this review, the immunoregulatory mechanisms identified at the preclinical level in combination with the different types of MSCs found in dental tissues are described, in addition to a description of the clinical trials in which MSCs from these sources have been applied.

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Podoplanin, a sialomucin-lik e transmembrane glycoprotein, is currently used as a specific marker for lymphatic vessels. However, podoplanin expression has also been linked to tooth development. To investigate the expression of podoplanin in odontomas, 86 tissue samples were classified and then analyzed using immunohistochemical methods. Formalin-fixed, paraffin-embedded specimens were collected and classified, followed by immunohistochemical examination. The majority of the odontomas (66.3%) were the compound type, and the remainder (33.7%) were the complex type. The patients ranged in age from 2 to 89 years (mean, 23.9 years), and 45 (52.3%) of them were male and 41 (47.7%) were female. The most common location for complex odontomas was the molar region of the mandibular bone, and that for compound odontomas was the maxillary incisor region. Immunohistochemistry revealed that developing and mature odontoblasts, Tomes' fibers, and pulp cells near podoplanin-positive odontoblasts were positive for podoplanin. In addition, podoplanin positivity was evident in secretory ameloblasts, but not in mature ameloblasts. The pattern of podoplanin expression in odontomas corresponds to development of the tooth germ, and appears to be influenced by the stage of differentiation of the lesion, suggesting that the protein may participate in the process of differentiation. (J Oral Sci 53, 67-75, 2011)

Biomaterial scaffolds house and direct cells to grow, exposing them to appropriate growth factors. Most of them are designed to degrade at a controlled rate as the new host tissue replaces them. Here, we show that scaffolds obtained through electrospinning of PVA with 3.5, 4.0, and 5.0 wt% of SA showed a gradual degradation rate under physiological conditions during 100 days of incubation. This behavior is proportional to the SA concentration used, with a mass loss of (41%, 47%, and 49% for each system) after 60 days. Moreover, the dielectric properties (EIS) of the scaffolds correlate with their degradation rate throughout the exposition period (100 days), as indicated by the observed decrease in resistance over time. The 4.0 wt% system showed the lowest capacitance value (1.5 10–5 F) and the highest resistance (4.6106 ohm‐cm2) behavior among all concentrations. Additionally, the morphological analysis through SEM and AFM showed a shrank in the surface morphology after the degradation process and determined the degree of roughness (Ra). Higher roughness prior to the cytocompatibility test promoted increased proliferation and adhesion of HaCat cells, as observed in the 4.0 wt% PVA/SA system (1422 nm Ra). These biomaterials have great potential in wound dressing applications.

Composite materials are used in bone tissue engineering because they mimic the structure of the extracellular matrix of bone. In this work, polylactic acid (PLA) fiber scaffolds prepared by air-jet spinning technique, were doped with different concentrations of SBA-15 ceramic (0.05, 0.1, and 0.15 wt%). The SBA-15 ceramic powder was made by the Sol-Gel process. Physicochemical characterization of PLA, SBA-15, and composite fiber scaffold was done by XRD, SEM, BET, FTIR, TGA, mechanical test, and biocompatibility assay, which were performed in a cell culture model with osteoblast cells. Our results showed a random nanofibers composite scaffold with an improvement in the physicochemical properties. The PLA fiber diameter increases as increases the content of SBA-15, and the mechanical properties were dose-dependent. SBA-15 shows the well-ordered mesoporous hexagonal structure with a pore size of 5.8 ± 0.2 nm and a specific surface area with a value of 1042 ± 89 m2/g. PLAfibers and composites have thermal stability up to 300°C, and thermal decomposition in the range 316-367°C. In vitro biocompatibility results showed that PLA/SBA-15 composite scaffold had no cytotoxicity effect in terms of cell adhesion and viability of osteoblast cells. Furthermore, the doped SBA-15 with 0.05% wt onto the polymer matrix could be useful in biomedical applications for bone tissue engineering.