A new multiphase calcium phosphate graft material improves bone healing-An in vitro and in vivo analysis.

This study aims to evaluate the potential of a novel biomaterial synthesized from amorphous calcium phosphate (ACP), octacalcium phosphate (OCP), and hydroxyapatite (HA) to repair critical-sized defects (CSD) in rabbit calvaria. In vitro analyses of cell viability, cell proliferation, formation of mineral nodules, and cell differentiation using qPCR were performed for comparing experimental calcium phosphate (ECP), deproteinized bovine bone (DBB), and beta-tricalcium phosphate (ß-TCP). Bilateral CSDs were created in 45 rabbit calvaria. Six groups were evaluated: ECP, ECP + fibrin sealant (ECP + S), coagulum, autogenous bone, DBB, and ß-TCP. Euthanasia was performed at 2, 4, and 8 weeks, followed by micro-computed tomography and histological and immunohistochemical analyses. Results from in vitro analyses revealed similar biocompatibility for all tested materials and a tendency for higher gene expression of some bone markers in the ECP group than in ß-TCP and DBB groups at 7 days. In contrast to that in DBB and ß-TCP groups, ECP displayed growing bone volume over total volume percentage (BV/TV%) with time in vivo. Histological analysis revealed a greater number of giant cells and reduced size of grafted particles in ECP during all periods of analysis. RUNX-2 expression was statistically lower in ECP than DBB at 2 and 4 weeks. Despite no statistical significance, ECP presented the highest absolute values for ALP-expression at 2, 4, and 8 weeks compared with other groups. Together, our findings indicate that a combination of the ACP, OCP, and HA phases into ECP is beneficial and promising for bone regeneration.

Strontium-loaded titanium-15molybdenum surface improves physicochemical and biological propertiesin vitro.

The titanium alloy composition and microdesign affect the dynamic interplay between the bone cells and titanium surface in the osseointegration process. The current study aimed to evaluate the surface physicochemical properties, electrochemical stability, and the metabolic response of the MC3T3-E1 cells (pre-osteoblast cell line) cultured onto titanium-15molybdenum (Ti-15Mo) discs treated with phosphoric acid (H3PO4) and sodium hydroxide (NaOH) and/or strontium-loading by the hydrothermal method. The x-ray dispersive energy spectroscopy (EDS) and x-ray diffraction (XRD) analysis showed no trace of impurities and the possible formation of hydrated strontium oxide (H2O2Sr), respectively. The confocal laser microscopy (CLSM) analysis indicated that titanium samples treated with strontium (Sr) showed greater surface roughness. The acid/alkali treatment prior to the hydrothermal Sr deposition improved the surface free energy and resistance to corrosion of the Ti-15Mo alloy. The acid/alkali treatment also provided greater retention of the Sr particles on the Ti-15Mo surfaces accordingly with inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. The AlamarBlue and fluorescence analysis indicated noncytotoxic effects against the MC3T3-E1 cells, which allowed cells' adhesion and proliferation, with greater cells' spreading in the Sr-loaded Ti-15Mo samples. These findings suggest that Sr deposition by the hydrothermal method has the potential to enhance the physicochemical properties of the Ti-15Mo previously etched with H3PO4and NaOH, and also improve the initial events related to cell-mediated bone deposition.

Three-dimensional printing and in vitro evaluation of poly(3-hydroxybutyrate) scaffolds functionalized with osteogenic growth peptide for tissue engineering.

Poly(3-hydroxybutyrate) (PHB) is a biodegradable and thermoprocessable biopolymer, making it a promising candidate for applications in tissue engineering. In the present study a structural characterization and in vitro evaluation were performed on PHB scaffolds produced by additive manufacturing via selective laser sintering (SLS), followed by post-printing functionalization with osteogenic growth peptide (OGP) and its C-terminal sequence OGP(10-14). The PHB scaffolds were characterized, including their morphology, porosity, thermal and mechanical properties, moreover OGP release. The results showed that SLS technology allowed the sintering of the PHB scaffolds with a hierarchical structure with interconnected pores and intrinsic porosity (porosity of 55.8 ±â€¯0.7% and pore size in the 500-700 µm range), and good mechanical properties. Furthermore, the SLS technology did not change thermal properties of PHB polymer. The OGP release profile showed that PHB scaffold promoted a controlled release above 72 h. In vitro assays using rat bone marrow stem cells showed good cell viability/proliferation in all the PHB scaffolds. Additionally, SEM images suggested advanced morphological differentiation in the groups containing osteogenic growth peptide. The overall results demonstrated that PHB biopolymer is potential candidate for 3D printing via SLS technology, moreover the OGP-containing PHB scaffolds showed ability to sustain cell growth to support tissue formation thereby might be considered for tissue-engineering applications.

A microscopic analysis of the effects of root surface scaling with different power parameters of Er,Cr:YSGG laser.

The aim of this study was to evaluate the effects of different power parameters of an Erbium, Cromium: Yttrium, Scandium, Gallium, Garnet laser (Er,Cr:YSGG laser) on the morphology, attachment of blood components (ABC), roughness, and wear on irradiated root surfaces. Sixty-five incisive bovine teeth were used in this study, 35 of which were used for the analysis of root surface morphology and ABC. The remaining 30 teeth were used for roughness and root wear analysis. The samples were randomly allocated into seven groups: G1: Er,Cr:YSGG laser, 0.5 W; G2: Er,Cr:YSGG laser, 1.0 W; G3: Er,Cr:YSGG laser, 1.5 W; G4: Er,Cr:YSGG laser, 2.0 W; G5: Er,Cr:YSGG laser, 2.5 W; G6: Er,Cr:YSGG laser, 3.0 W; G7: scaling and root planning (SRP) with manual curettes. The root surfaces irradiated by Er,Cr:YSGG at 1.0 W and scaling with manual curettes presented the highest degrees of ABC. The samples irradiated by the Er,Cr:YSGG laser were rougher than the samples treated by the manual curette, and increasing the laser power parameters caused more root wear and greater roughness on the root surface. The Er,Cr:YSGG laser is safe to use for periodontal treatment, but it is not appropriate to use irradiation greater than 1.0 W for this purpose.