Effect of Hydroxyapatite Microspheres, Amoxicillin–Hydroxyapatite and Collagen–Hydroxyapatite Composites on Human Dental Pulp-Derived Mesenchymal Stem Cells

Abstract

In this study, the preparation and characterization of three hydroxyapatite-based bioactive scaffolds, including hydroxyapatite microspheres (HAps), amoxicillin–hydroxyapatite composite (Amx–HAp), and collagen–hydroxyapatite composite (Col–HAp) were performed. In addition, their behavior in human dental pulp mesenchymal stem cell (hDPSC) culture was investigated. HAps were synthesized through the following methods: microwave hydrothermal, hydrothermal reactor, and precipitation, respectively. hDPSCs were obtained from samples of third molars and characterized by immunophenotypic analysis. Cells were cultured on scaffolds with osteogenic differentiation medium and maintained for 21 days. Cytotoxicity analysis and migration assay of hDPSCs were evaluated. After 21 days of induction, no differences in genes expression were observed. hDPSCs highly expressed the collagen IA and the osteonectin at the mRNA. The cytotoxicity assay using hDPSCs demonstrated that the Col–HAp group presented non-viable cells statistically lower than the control group (p = 0.03). In the migration assay, after 24 h HAps revealed the same migration behavior for hDPSCs observed compared to the positive control. Col–HAp also provided a statistically significant higher migration of hDPSCs than HAps (p = 0.02). Migration results after 48 h for HAps was intermediate from those achieved by the control groups. There was no statistical difference between the positive control and Col–HAp. Specifically, this study demonstrated that hydroxyapatite-based bioactive scaffolds, especially Col-Hap, enhanced the dynamic parameters of cell viability and cell migration capacities for hDPSCs, resulting in suitable adhesion, proliferation, and differentiation of this osteogenic lineage. These data presented are of high clinical importance and hold promise for application in therapeutic areas, because Col–HAp can be used in ridge preservation, minor bone augmentation, and periodontal regeneration. The development of novel hydroxyapatite-based bioactive scaffolds with clinical safety for bone formation from hDPSCs is an important yet challenging task both in biomaterials and cell biology.

Preparation and Characterization of a Novel Hydroxyapatite-Capsaicin Composite Intended for the In-Office Dental Bleaching Use

“…Some typical bands for PO4 3− appeared at 470, 568, 602, 964, 1041, and 1093 cm −1 . These assignments confirm that these nanoparticulate products were successfully synthesized and were consistent to HAp [37]. Nanocomposite showed an overlap of the raw materials signals, and no novel signal was evidenced for these formulations.…”

“…Pure drug (CAP) showed intense diffraction peaks at Bragg angles 2θ = 5.84° (24,000), 11.71° (4500), 16.4° (1240), and 19.8° (1870) which confirmed the crystalline structure of capsaicinoids characterized by sharp and well-defined peaks [45]. The XRPD pattern of nano-HAp presented a single crystalline phase corresponding to HAp, with characteristic peaks at 10.84°, 21.79°, 28.89°, 31.73°, 32.86°, and 39.74° [37]. The HAp-CAP nanocomposite obtained showed crystalline diffraction patterns similar to nano-HAp.…”

“…The precipitate was aged for 24 h, vacuum filtered, and the resulting precipitate was dried in an oven for 24 h at 100 °C. After drying, the HAp powders were ground in mortar and sieved through 200 mesh ASTM (75 μm) [37].…”

“…The HAp-CAP nanocomposite was prepared by the method of precipitation [37]. The composite synthesis was performed in a 4:1 ratio using 3.2 g of the previously synthesized nano-HAp and 0.8 g of CAP in 99.5% ethyl alcohol (q.s.p) and zirconia beads at SpeedMixer ® (FlackTek SpeedMixer ® DAC 150.1 FV-K, Landrum, South Caroline) under agitation of 3000 rpm for 3 h to provide the grinding process.…”

Hydroxyapatite-Tethered Peptide Hydrogel Promotes Osteogenesis

“…Hydroxyapatite (HAp) constitutes the major inorganic component in natural bones. Nanostructured HAp particles possess high osteoinductivity [ 4 , 5 , 6 ] and have been widely used in bone regenerative engineering [ 7 , 8 ]. However, HAp is very stable with low solubility in physiological conditions.…”