Bone tissue substitutes are increasing in importance. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) act as a cell matrix and improve its mechanical properties. One of their raw materials is marine-origin by-products. Objectives: To synthesize, characterize, and evaluate the cellular cytotoxicity of a 3D biomaterial based on HA and β-TCP from mussel shells. Methods: We prepared pellets with 150, 200, and 250 mg and evaluated them through sintering, XRD, FTIR, ICP-OES, Scanning Electron Microscopic (SEM), and immunocytochemical tests. The Alamar Blue method was applied to the Balb-T3T cell line within 72 h to evaluate cytotoxicity. Results: Our biomaterials presented a smooth surface with slight irregularity and porosities presenting different diameters and morphologies and showed chemical, morphological, and ultrastructural similarity to bone hydroxyapatite, mainly the 150 and 200 mg pellets. Significance: We produced promising HA/β-TCP bioceramics with characteristics that allowed cell culture, promoting adhesion, spreading, and proliferation.

Aim: In vitro evaluation of the influence of bovine xenogenic biomaterials on stem cells from human exfoliated deciduous teeth (SHEDs). The study was divided into three groups: 1) group C (control), containing only MSCs; 2) group BP, containing MSCs and Bonefill Porous®; 3) group BO, containing MSCs and Bio-Oss®. MSCs were derived from a deciduous tooth from a 7-year-old male donor. An aliquot of cells was subjected to immunophenotyping by flow cytometry. Cell viability (neutral red), cytotoxicity (MTT), and cell proliferation (crystal violet) assays were performed. All groups underwent morphological analysis by light microscopy (LM), and the biomaterial with superior performance was submitted to evaluation by scanning electron microscopy (SEM). Time points of 24, 48, and 72 h of culture were used. All results were evaluated with a significance level of 0.05. Results showed that both biomaterials maintained cell viability and cytotoxicity similar to the control. The BO group showed smaller cell proliferation compared to the other groups. In LM evaluation, the BP group showed more spread and adherent cells than the BO group. In SEM, cells of the BP group showed characteristics of more active cells than those of the control. Bovine xenogenic biomaterials positively influenced SHEDs, while the BP group seemed to present higher potential with SHEDs for future application within in vivo and/or clinical studies.

Inorganic bovine bone matrix (IBBM) is a biomaterial with proven osteoconductive functionalities. The objective of this study was to assess the in vivo bone regeneration functionalities of IBBM modified or not by an experimental MOE in sheep. MOE synthesis was performed by suspending nacre particles (0.05 g, diameters < 0.01 mm) in anhydrous acetic acid (pH 7, 5 mL, 25°C, 72 hours) using magnetic stirring. Polyethylene carriers (d= 5.0 mm, l= 10.0 mm, open ends) of negative control (sham) or experimental groups (IBBM or MOE-modified IBBM) were placed (n=3 conditions /animal; intramuscularly) adjacent to the lower spine of adult sheep (8 animals, » 45 Kg, 2 years old). Tissues were harvested (at 3 or 6 months) after implantation in preparation for histological (H), morphometrical (MM) and immunohistochemical analyses (IH; Wnt-3a, CD34, Vimentin and PREF-1). MM data were tested for normality and variance homogeneity using the Shapiro-Wilk and Levene tests, and Mann Whitney and Kruskal-Wallis, respectively. IM data were analyzed using two-way ANOVA and Tukey tests. Differences (p < 0.05) were observed between experimental groups (IBBM and IBBM+MOE at both 3 and 6 months) and controls (sham) for total area; Differences were not found for presence of remnant particles among experimental groups. The highest formation of bone was observed with IBBM+MOE (6-months). No differences (p > 0.05) were found on IM analysis (CD34, Vimentin, PREF-1, Wnt3a). Results indicated that experimental materials (IBBM+MOE) display promising functionalities. Additional studies are necessary to define biomaterials’ longitudinal effects and long-term biocompatibility properties.

The scaffolds and their interaction with mesenchymal stem cells are objects of study in bioengineering and tissue repair. Mechanisms such as surface adhesion, proliferation, viability, and cytotoxicity are essential for the development of therapies. The present study analyzed the influence of platelet-rich fibrin (PRF) in viability, cytotoxicity, and proliferation of stem cells from human exfoliated deciduous teeth (SHED) exposed to bovine biomaterial surfaces. The studied groups were divided and analyzed as follows: (S) only SHED as control Group; (SB) SHED + biomaterial; (SBP) SHED + biomaterial + PRF. Analyses of cells seeded in 24-well plates were performed after 24, 48 and 72 hours. Individual groups were subjected to viability, cytotoxicity and cell proliferation tests using neutral red, MTT and crystal violet, respectively; and in the 72-hour group, scanning electron microscopy (SEM) was performed to record cell ultra-morphology. Data were submitted to statistical analysis by two-factor ANOVA with a significance level of 5%. The results demonstrated a better performance in the viability/cytotoxicity and proliferation of stem cells for the group (SBP) in comparison to the group (SB) and the group (S). The applied statistical tests showed that the biomaterial factor, time, and interaction between them gave rise to results with statistical significance. SHED submitted to bovine biomaterial were more viable, proliferative and with lower toxicity when associated with PRF. PRF seemed to activate the metabolism of stem cells in culture, indicating that such an association can bring an effective benefit in clinical outcome.

Introduction: Umbilical cord-derived mesenchymal stem cells, especially from Wharton jelly (WJ-MSCs), are a promising source for regenerative medicine due to their low immunogenicity, immunomodulatory properties, and ethical sourcing

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