OBJECTIVE: This study aimed to determine the potential of ascorbic acid alone in inducing differentially expressed osteoblast-related proteins in dental stem cells via the liquid chromatography-mass spectrometry/ mass spectrometry (LC-MS/MS) approach.
METHODS: The cells were isolated from deciduous (SHED) and permanent teeth (DPSC) and induced with 10 μg/mL of ascorbic acid. Bone mineralisation and osteoblast gene expression were determined using von Kossa staining and reverse transcriptase-polymerase chain reaction. The label-free protein samples were harvested on days 7 and 21, followed by protein identification and quantification using LC-MS/MS. Based on the similar protein expressed throughout treatment and controls for SHED and DPSC, overall biological processes followed by osteoblast-related protein abundance were determined using the PANTHER database. STRING database was performed to determine differentially expressed proteins as candidates for SHED and DPSC during osteoblast development.
RESULTS: Both cells indicated brownish mineral stain and expression of osteoblast-related genes on day 21. Overall, a total of 700 proteins were similar among all treatments on days 7 and 21, with 482 proteins appearing in the PANTHER database. Osteoblast-related protein abundance indicated 31 and 14 proteins related to SHED and DPSC, respectively. Further analysis by the STRING database identified only 22 and 11 proteins from the respective group. Differential expressed analysis of similar proteins from these two groups revealed ACTN4 and ACTN1 as proteins involved in both SHED and DPSC. In addition, three (PSMD11/RPN11, PLS3, and CLIC1) and one (SYNCRIP) protein were differentially expressed specifically for SHED and DPSC, respectively.
CONCLUSION: Proteome differential expression showed that ascorbic acid alone could induce osteoblastrelated proteins in SHED and DPSC and generate specific differentially expressed protein markers.
METHODS: A total of 12 PD bags (3 for each type of solution) containing ceftazidime and heparin were prepared and stored at 4°C for 120 hours, and then at 25°C for 6 hours, and finally at 37°C for 12 hours. An aliquot was withdrawn after predefined time points and analyzed for the concentration of ceftazidime and heparin using high-performance liquid-chromatography (HPLC). Samples were assessed for pH, color changes, particle content, and anticoagulant activity of heparin.
RESULTS: Ceftazidime and heparin retained more than 91% of their initial concentration when stored at 4°C for 120 hours followed by storage at 25°C for 6 hours and then at 37°C for 12 hours. Heparin retained more than 95% of its initial activity throughout the study period. Particle formation was not detected at any time under the storage conditions. The pH and color remained essentially unchanged throughout the study.
CONCLUSIONS: Ceftazidime-heparin admixture retains its stability over long periods of storage at different temperatures, allowing its potential use for PDAP treatment in outpatient and remote settings.