The gentamicin sulfate carried calcium sulfate (GSCS) implants were fabricated by the coagulating method, and the release rate of the gentamicin tested by UV-spectrometer and the absorbing rate of the calcium sulfate carrier in vitro were studied. The release patterns of two types of GSCS were compared. The trend of daily weight loss of GSCS was found being similar to that of pure calcium sulfate, which suggested that the gentamicin part has little effect on the absorbing pattern of calcium sulfate. The release rate of gentamicin is controlled by the erosion rate of calcium sulfate, so GSCS with different amount of gentamicin has the same release patterns. The DRP value of ED is higher than that of CO during the early stage, while the DRP value of ED is lower than that of CO during the late stage. The GSCS samples were implanted into the defect mold on the radii of the rabbits to investigate the potential for the use of GSCS implants as bone fillers, and the results revealed that new bone had been induced in a great part of the defect at 14 weeks after operation.
Animals ; Anti-Bacterial Agents ; administration & dosage ; pharmacokinetics ; Bone Regeneration ; drug effects ; Calcium Sulfate ; administration & dosage ; Gentamicins ; administration & dosage ; pharmacokinetics ; Implants, Experimental ; Rabbits ; Radius Fractures ; therapy

Objective:To explore the effect and molecular mechanism of circ_0000263 on HeLa cell activity, apoptosis, telomerase activity, and radiosensitivity.Methods:The Hela cells were divided into si-NC, si-circ, vector, circ_0000263, anti-NC, anti-miR-338-3p, miR-NC, miR-338-3p, si-circ+anti-NC, si-circ+ anti-miR-338-3p, si-circ+vector, si-circ+TERT, sh-NC, sh-circ groups. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expressions of circ_0000263 and miR-338-3p. Cell clone formation array was used to detect cell survival; cell counting kit-8 (CCK-8) to detect cell proliferation; flow cytometry to detect apoptosis; western blot method to detect the expressions of proliferating cell nuclear antigen (PCNA), Cleaved-casp3, telomerase reverse transcriptase (TERT) proteins; double luciferase assay to detect the targeting relationships of circ_0000263 and miR-338-3p, miR-338-3p and TERT; telomere repeat amplification enzyme linked immunosorbent assay (TRAR-ELISA) to detect telomerase activity.Results:Circ_0000263 was highly expressed in Hela cells, miR-338-3p was low expressed, and TERT was highly expressed; circ_0000263 was also highly expressed in Hela cells treated with radiation ( P＜0.05). Knockdown of circ_0000263 inhibited the clone formation and cell proliferation ability of HeLa cells, and enhanced the radiosensitivity and apoptosis of HeLa cells. In contrast, knockdown of circ_0000263 decreased PCNA protein expression level and enhanced Cleaved-casp3 protein expression level in HeLa cells ( P＜0.05). The apoptosis rate in the si-circ group was (13.19±1.12)%, which was higher than (6.80±0.62)% of si-NC group ( P＜0.05). The apoptosis rate in the si-circ+4 Gy group was (24.82±1.57)%, which was higher than (17.00±0.96)% of si-NC+4 Gy group ( P＜0.05). Circ_0000263 targeted regulated miR-338-3p, and miR-338-3p targeted regulated TERT. MiR-338-3p was lowly expressed in HeLa cells, and knockdown of circ_0000263 elevated miR-338-3p expression level in HeLa cells. Circ_0000263 regulated TERT expression and inhibited telomerase activity through miR-338-3p. MiR-338-3p/TERT can restore the effect of circ_0000263 on the radiosensitivity of Hela cells. The apoptosis rate in the si-circ+anti-NC group was (27.37±0.89)%, which was higher than (18.22±1.18)% of the si-circ+anti-miR-338-3p group ( P＜0.05). The apoptosis rate in the si-circ+vector group was (27.55±0.48)%, which was higher than (20.10±0.68)% of si-circ+TERT group ( P＜0.05). After 72 hours of radiation by 4 Gy, the cell survival fraction of si-circ+anti-NC group was 0.41±0.02, which was lower than 0.66±0.03 of the si-circ+anti-miR-338-3p group ( P＜0.05); the cell survival fraction of si-circ+vector group was 0.42±0.05, which was lower than 0.70±0.03 of si-circ+TERT group ( P＜0.05). Conclusion:Inhibiting the expression of circ_0000263 supresses the proliferation of Hela cells by regulating miR-338-3p/TERT, promotes apoptosis, inhibits telomerase activity, increases the radiosensitivity of cancer cells, and provides a theoretical basis for improving the radiosensitivity of Hela cells.

Objective:To explore the effect and molecular mechanism of circ_0000263 on HeLa cell activity, apoptosis, telomerase activity, and radiosensitivity.Methods:The Hela cells were divided into si-NC, si-circ, vector, circ_0000263, anti-NC, anti-miR-338-3p, miR-NC, miR-338-3p, si-circ+anti-NC, si-circ+ anti-miR-338-3p, si-circ+vector, si-circ+TERT, sh-NC, sh-circ groups. Reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR) was used to detect the expressions of circ_0000263 and miR-338-3p. Cell clone formation array was used to detect cell survival; cell counting kit-8 (CCK-8) to detect cell proliferation; flow cytometry to detect apoptosis; western blot method to detect the expressions of proliferating cell nuclear antigen (PCNA), Cleaved-casp3, telomerase reverse transcriptase (TERT) proteins; double luciferase assay to detect the targeting relationships of circ_0000263 and miR-338-3p, miR-338-3p and TERT; telomere repeat amplification enzyme linked immunosorbent assay (TRAR-ELISA) to detect telomerase activity.Results:Circ_0000263 was highly expressed in Hela cells, miR-338-3p was low expressed, and TERT was highly expressed; circ_0000263 was also highly expressed in Hela cells treated with radiation ( P＜0.05). Knockdown of circ_0000263 inhibited the clone formation and cell proliferation ability of HeLa cells, and enhanced the radiosensitivity and apoptosis of HeLa cells. In contrast, knockdown of circ_0000263 decreased PCNA protein expression level and enhanced Cleaved-casp3 protein expression level in HeLa cells ( P＜0.05). The apoptosis rate in the si-circ group was (13.19±1.12)%, which was higher than (6.80±0.62)% of si-NC group ( P＜0.05). The apoptosis rate in the si-circ+4 Gy group was (24.82±1.57)%, which was higher than (17.00±0.96)% of si-NC+4 Gy group ( P＜0.05). Circ_0000263 targeted regulated miR-338-3p, and miR-338-3p targeted regulated TERT. MiR-338-3p was lowly expressed in HeLa cells, and knockdown of circ_0000263 elevated miR-338-3p expression level in HeLa cells. Circ_0000263 regulated TERT expression and inhibited telomerase activity through miR-338-3p. MiR-338-3p/TERT can restore the effect of circ_0000263 on the radiosensitivity of Hela cells. The apoptosis rate in the si-circ+anti-NC group was (27.37±0.89)%, which was higher than (18.22±1.18)% of the si-circ+anti-miR-338-3p group ( P＜0.05). The apoptosis rate in the si-circ+vector group was (27.55±0.48)%, which was higher than (20.10±0.68)% of si-circ+TERT group ( P＜0.05). After 72 hours of radiation by 4 Gy, the cell survival fraction of si-circ+anti-NC group was 0.41±0.02, which was lower than 0.66±0.03 of the si-circ+anti-miR-338-3p group ( P＜0.05); the cell survival fraction of si-circ+vector group was 0.42±0.05, which was lower than 0.70±0.03 of si-circ+TERT group ( P＜0.05). Conclusion:Inhibiting the expression of circ_0000263 supresses the proliferation of Hela cells by regulating miR-338-3p/TERT, promotes apoptosis, inhibits telomerase activity, increases the radiosensitivity of cancer cells, and provides a theoretical basis for improving the radiosensitivity of Hela cells.