We investigated the possibility of employing human umbilical perivascular cells (HUCPVCs) within the context of finding an alternative source of mesenchymal stromal cells (MSC) for bone tissue engineering. Since it has previously been reported that conditioned medium (CM) from osteogenic bone marrow (BM) MSCs can potentiate osteogenic differentiation in a secondary cell population, we also employed BM-MSCs to generate CM to stimulate osteogenesis in the HUCPVCs. The BM-MSCs were a commercially available immortalized human cell line. In vitro assays showed negligible levels of osteogenic gene expression in HUCPVCs compared to BM-MSC, but alkaline phosphatase was detected when HUCPVC were cultured in osteogenic medium in the presence of CM from BM-MSC. An in vivo assay employing a rat calvarial osteotomy defect, together with a collagen sponge scaffold, showed that HUCPVCs provided statistically significant bony repair compared to controls. BM-MSC loaded scaffolds were not statistically different from either controls or HUCPVCs. The addition of BM-MSC CM to HUCPVCs also produced no statistically significant difference to the bone formed by HUCPVCs alone. Our results demonstrate that the in vitro assays employed did not predict in vivo outcomes, and that the BM-MSC cell line employed, or CM from such cells, provided no osteogenic advantage over the use of HUCPVCs alone.
Rapid progress has been made in terms of metal nanoparticles studied in numerous fields. Metal nanoparticles have also been used in medical research, and antibacterial properties and anticancer effects have been reported. However, the underlying mechanism responsible for these effects has not been fully elucidated. Therefore, the present study focused on platinum nanoparticles (PtNPs) and examined their antibacterial properties and functional potential for decomposing organic matter, considering potential applications in the dental field. PtNPs were allowed to react with dental-related bacteria (Streptococcus mutans; Enterococcus faecalis, caries; Porphyromonas gingivalis, and endodontic and periodontal lesions). Antibacterial properties were evaluated by measuring colony formation. In addition, PtNPs were allowed to react with albumin and lipopolysaccharides (LPSs), and the functional potential to decompose organic matter was evaluated. All evaluations were performed in vitro. Colony formation in all bacterial species was completely suppressed by PtNPs at concentrations of >5 ppm. The addition of PtNPs at concentrations of >10 ppm significantly increased fragmentation and decomposition. The addition of PtNPs at concentrations of >125 pico/mL to 1 EU/mL LPS resulted in significant amounts of decomposition and elimination. The results revealed that PtNPs had antibacterial effects against dental-related bacteria and proteolytic potential to decompose proteins and LPS, an inflammatory factor associated with periodontal disease. Therefore, the use and application of PtNPs in periodontal and endodontic treatment is considered promising.
Previous reports have shown that azithromycin (AZM), a macrolide antibiotic, affects collagen synthesis and cytokine production in human gingival fibroblasts (hGFs). However, there are few reports on the effect of AZM on human periodontal ligament fibroblasts (hPLFs). In the present study, we comparatively examined the effects of AZM on hGFs and hPLFs. We monitored the reaction of AZM under lipopolysaccharide (LPS) stimulation or no stimulation in hGFs and hPLFs. Gene expression analyses of interleukin-6 (IL-6), interleukin-8 (IL-8), matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-2 (MMP-2), and Type 1 collagen were performed using reverse transcription-polymerase chain reaction (RT-PCR). Subsequently, we performed Western blotting for the analysis of the intracellular signal transduction pathway. In response to LPS stimulation, the gene expression levels of IL-6 and IL-8 in hGFs increased due to AZM in a concentration-dependent manner, and phosphorylation of nuclear factor kappa B (NF-κB) was also promoted. Additionally, AZM caused an increase in MMP-1 expression in hGFs, whereas it did not affect the expression of any of the analyzed genes in hPLFs. Our findings indicate that AZM does not affect hPLFs and acts specifically on hGFs. Thus, AZM may increase the expression of IL-6 and IL-8 under LPS stimulation to modify the inflammatory response and increase the expression of MMP-1 to promote connective tissue remodeling.
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