Background:Cancer stem cells (CSCs) paradigm suggests that CSCs might have important clinical implications in cancer therapy. Previously, we reported that accumulation efficiency of CSCs is different post low- and high-LET irradiation in 48 h.Methods:Cancer stem cells and non-stem cancer cells (NSCCs) were sorted and functionally identified through a variety of assays such as antigen profiles and sphere formation. Inter-conversion between CSCs and NSCCs were in situ visualised. Cancer stem cells proportions were assayed over multiple generations under normal and irradiation surroundings. Supplement and inhibition of TGF-β1, as well as immunofluorescence assay of E-cadherin and Vimentin, were performed.Results:Surface antigen markers of CSCs and NSCCs exist in an intrinsic homoeostasis state with spontaneous and in situ visualisable inter-conversions, irrespective of prior radiations. Supplement with TGF-β1 accelerates the equilibrium, whereas inhibition of TGF-β signalling disturbs the equilibrium and significantly decreases CSC proportion. Epithelial mesenchymal transition (EMT) might be activated during the process.Conclusion:Our results indicate that the intrinsic inter-conversion and dynamic equilibrium between CSCs and NSCCs exist under normal and irradiation surroundings, and TGF-β might have important roles in the equilibrium through activating EMT.

Conventional methods of endothelial cell culture on monolayers and beads require enzymatic digestion, traumatic scraping, or centrifugation to transfer cells to other experimental systems. Gelfoam, a porous gelatin block, not only supports the growth of bovine pulmonary artery endothelial cells but also allows the rapid transfer of cell-laden blocks from one experimental system to another with minimal intervention. This property has been shown to be especially useful for the rapid fixation of endothelial cells for microscopy using standard histologic methods. Histology confirmed that the trabecular nature of the substrate allows endothelial cells to line the interstices of the sponge matrix and grow in a configuration that simulates the appearance of the endothelium in small vessels and capillaries. The inoculation of 1 x 10(5) endothelial cells on 7.5 mg Gelfoam (24 x 8 x 2 mm blocks) was enhanced by fibroblast growth factor and resulted in cell attachment by day 2 with a cell doubling time of 1.7 days. In addition, endothelial cells completely infiltrated 1, 5 and 7.5 mg Gelfoam blocks, as verified by histology. Assays to quantify cell number and protein were easily performed. To facilitate cell counting, the Gelfoam matrix was rapidly removed by the addition of 0.05 mg/ml collagenase, a concentration that interfered minimally with the assay for cellular protein concentration. The data demonstrate that Gelfoam is a suitable support growth matrix for the in vitro culture of bovine pulmonary artery endothelial cells.

Aim To investigate the effects of a bioactive glass with a high proportion of phosphorus (BG‐hP) on the repair and regeneration of dental pulps in rats under an inflammatory microenvironment. Methodology Human dental pulp cells (hDPCs) stimulated with 1 μg mL−1 lipopolysaccharide (LPS) were co‐cultured with 0.1 mg mL−1 BG‐hP. Cell proliferation was detected by 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5 diphenyltetrazolium bromide (MTT) assays. The expression of inflammation‐related genes and odontogenic differentiation‐related genes was determined by real‐time PCR. Alizarin red staining was used to detect the formation of mineralized nodules. Coronal pulp tissues of rat molars were stimulated with 10 mg mL−1 LPS and then treated with BG‐hP. The expression of inflammation‐related genes in pulp tissue was determined by real‐time PCR. Haematoxylin‐eosin staining and Masson staining were performed to observe the inflammatory response and mineralized matrix formation, after subcutaneous implantation in nude mice, at 3 days and 4 weeks, respectively. Analysis of variance was performed to measure statistical significance (P < 0.05). Results BG‐hP significantly reduced expression of interleukin‐6 (IL‐6) and IL‐8 and significantly upregulated the expression of IL‐10, IL‐4 and transforming growth factor‐β1 of the LPS‐stimulated hDPCs (P < 0.05). BG‐hP significantly inhibited the initial cell number (P < 0.05), but the hDPCs stimulated by LPS and co‐cultured with BG‐hP maintained the same proliferation rate as the untreated hDPCs. BG‐hP significantly promoted the expression of dentine matrix protein‐1 and dentine sialophosphoprotein and the mineralization capacity of the LPS‐stimulated hDPCs (P < 0.05). Furthermore, BG‐hP significantly downregulated the expression of Il‐6 and reduced the inflammatory response of the LPS‐stimulated pulp tissue 3 days after subcutaneous implantation (P < 0.05). Four weeks after subcutaneous implantation, BG‐hP induced the formation of a continuous layer of dentine‐like structure with dentinal tubules and polarizing odontoblast‐like cells aligned along it in the LPS‐stimulated pulp tissue. Conclusion The present preliminarily results demonstrated that the bioactive glass with a high proportion of phosphorus inhibited the inflammatory response and promoted the formation of a pulp‐dentine complex in a rat experimental model. This study provides a foundation for the construction of materials with the dual functions of exerting anti‐inflammatory effects and promoting tissue regeneration to meet the needs of dental pulp repair and regeneration.