BACKGROUND: Ions doping is an important method for the modification of bioceramic.OBJECTIVE: To evaluate a novel co-substituted bioceramic scaffolds as bone repair material.METHODS: The microstructure and crystallization of the scaffolds were detected by scanning electron microscope and X-ray diffraction. Compression strength test,degradation test and cell culture experiment were assumed to evaluate the properties of KSCPP in vitro. After a short period of muscle pouches implantation,the performance of KSCPP in vivo was evaluated.RESULTS AND CONCLUSION: The results show that KSCPP scaffold has a higher compressive strength and degradation rate. Moreover,the MTT assay and implantation test reveal that the KSCPP scaffold exhibits lower cytotoxicity and better tissue biocompatibility than CPP and HA. The study proved the great potential of KSCPP in bone repair applications.

BACKGROUND: Strontium-doped calcium polyphosphate (SCPP) is a new type of bone repair materials with good biocompatibility and controlled degradation. The preliminary studies of our group indicate their role in promoting angiogenesis,but its mechanism is unclear.OBJECTIVE: By co-culturing osteoblasts ROS17/2.8 with SCPP in vitro to observe cell proliferation and the secretion of vascular endothelial growth factor (VEGF).DESIGN, TIME AND SETTING: A contrast study was performed at the Laboratory of Tissue Engineering of Sichuan University from October 2008 to June 2009.MATERIALS: A series of calcium polyphosphate (CPP) respectively containing 0%, 1 %, 2%, 5%, 8%, and 10% Sr~(2+) were prepared. ROS17/2.8 osteoblastic cell strain was provided by Laboratory of Transplantation Immunity and Transplantation Engineering, West China Hospital, Sichuan University.METHODS: ①Preparation of cell scaffold complexes: The materials were placed in 24-well plates, then 300 μL cell suspension with a concentration of 2×10~7 cells/Lwas inoculated into each hole. These complexes were cultured for 14 days and the liquid was changed every two days. ②These complexes were measured by MTT assay to observe the proliferation of osteoblasts on the 1~(st), 3~(rd), 5~(th), 7~(th), 10~(th) and 14~(th) days, respectively. ③ The centrifugal supernatant of the complex cultured for seven days was measured by ELISA assay to check the secretion of VEGF.MAIN OUTCOME MEASURES: The proliferation of osteoblastic cells on SCPP and CPP was observed. The amount of VEGF protein secreting from osteoblastic cells was detected.RESULTS: The results of MTT showed that, compared with the CPP group, SCPP groups could promote the proliferation of osteoblasts, and 8% SCPP group was the best; ELISA results showed that, compared with the CPP group, SCPP groups could increase the amount of VEGF protein secretion, of which the promoting role of 8% SCPP was the most obvious (P < 0.05).CONCLUSION: When cultured with osteoblasts, SCPP can promote cell proliferation, and can significantly increase the secretion of VEGF; moreover, 8% SCPP is the best, which reveals a certain mechanism of its promoting angiogenesis.

Objective:To explore more reliable standards for identifying vestibular hair cells of saccule and utricle prepared in studies with patch clamp technique under inverted phase contrast microscope. Method:The length and width of two types hair cells were measured besides the length of cilia,and all datas were analyzed statistically.Result:The width and length of cilia of two types hair cells in saccule and utricle from guinea pig were similar. The length of type Ⅰ was longer than that of type Ⅱ,SO the ratio between length and width was larger and the ratio of the length between cilia and cell body was small.Conclnsion:Two type'S hair cells of saccule and utricle from guinea pig may be distinguished through the ratio of cell body's length and width even the ratio of the length between cilia and cell body,besides the standards before.

BACKGROUND: Strontium-doped calcium polyphosphate (SCPP), as a new repairing material, has been demonstrated to have favorable biocompatibility and biodegradability and some effects on promoting self-angiogenesis. However, the mechanism remains still unknown. OBJECTIVE: Endothelial cells were cultured with SCPP scaffolds in vitro, as well as the cell proliferation and angiogenic factor matrix metalloproteinase-2 (MMP-2) secretion were observed. DESIGN,TIME AND SETTING: A contrast study was performed at the Laboratory of Tissue Engineering of Sichuan University from September 2008 to April 2009. MATERIALS: A series of calcium polyphosphate (CPP) respectively containing 1 %, 2%, 5%, 8%, and 10% Sr~(2+) were prepared.METHODS: ① Materials were plated on 24-well culture plate,and endothelial cell suspension (300 μL) were seeded on 24-well culture plate at the concentration of 3×10~7/L and cultured with 200 uL RPMI1640 culture media. Endothelial cell proliferation was observed using MTT method at days 1,3,5, and 7 after culture. ② CPP and 8% SCPP were plated on 24-well culture plate, and endothelial cell suspension (300 uL) was then incubated in 24-well culture plate at the concentration of 1x10~8/L and cultured with 600 uL RPMI1640 culture media. The morphology of endothelial cells was observed by scanning electron microscopy (SEM) at day 5 after culture.③ Endothelial cells were co-cultured with SCPP of various Sr~(2+) contents for 5 days. After confluence, cells were centrifuged to obtain supernatant. Angiogenic factor MMP-2 secretion was evaluated by ELISA assay.MAIN OUTCOME MEASURES: The proliferation and morphology of endothelial cells on SCPP and CPP were observed. The amount of endothelial cells-derived MMP-2 protein secretion was detected. RESULTS: MTT method demonstrated that the proliferation of endothelial cells on the 8% SCPP scaffold showed a higher level compared to CPP, and other SCPP groups. Scanning electron microscope results suggested that endothelial cells on 8% SCPP had a better growth status and biological activity. ELISA results indicated that angiogenic factor MMP-2 expression on the SCPP was promoted compared with that of CPP, and 8% SCPP showed the highest expression (P < 0.05). CONCLUSION: SCPP has good compatibility with endothelial cells,promoting angiogenesis and enhancing the angiogenic factor MMP-2 expression.

Purpose: Breast cancer (BC) is a predominant malignancy globally, surpassing lung cancer in terms of diagnostic frequency, with an escalating incidence rate in recent decades.Recent studies have investigated the role of protein kinase C zeta (PRKCZ) in diverse cellular processes in cancer biology. In this study, we evaluated the association between PRKCZ and deleterious outcomes in BC and elucidated the mechanisms underlying its expression in breast carcinoma. Methods: The correlation between PRKCZ and survival rates of patients with BC was investigated using The Cancer Genome Atlas database. The methylation status of the PRKCZ promoter was analyzed using the UALCAN database. Furthermore, we investigated the mechanisms underlying PRKCZ inactivation in BC by treatment with transferase inhibitors, methylation-specific polymerase chain reaction (PCR) analysis, western blotting, and luciferase reporter gene assays. The degree of methylation and expression levels of PRKCZ, as regulated by DNA methyltransferase 1 (DNMT1), were quantified using quantitative PCR and western blotting. Results: Our analysis revealed that decreased expression of PRKCZ in BC was significantly correlated with poor clinical prognosis. Furthermore, we observed that hypermethylation of the PRKCZ promoter contributed to its reduced expression in BC. Notably, DNMT1 has been identified as a critical regulator of PRKCZ methylation. Conclusion Our findings elucidate the tumor-suppressive function of PRKCZ and provide insights into the molecular mechanisms underlying its downregulation in BC.

Purpose: Breast cancer (BC) is a predominant malignancy globally, surpassing lung cancer in terms of diagnostic frequency, with an escalating incidence rate in recent decades.Recent studies have investigated the role of protein kinase C zeta (PRKCZ) in diverse cellular processes in cancer biology. In this study, we evaluated the association between PRKCZ and deleterious outcomes in BC and elucidated the mechanisms underlying its expression in breast carcinoma. Methods: The correlation between PRKCZ and survival rates of patients with BC was investigated using The Cancer Genome Atlas database. The methylation status of the PRKCZ promoter was analyzed using the UALCAN database. Furthermore, we investigated the mechanisms underlying PRKCZ inactivation in BC by treatment with transferase inhibitors, methylation-specific polymerase chain reaction (PCR) analysis, western blotting, and luciferase reporter gene assays. The degree of methylation and expression levels of PRKCZ, as regulated by DNA methyltransferase 1 (DNMT1), were quantified using quantitative PCR and western blotting. Results: Our analysis revealed that decreased expression of PRKCZ in BC was significantly correlated with poor clinical prognosis. Furthermore, we observed that hypermethylation of the PRKCZ promoter contributed to its reduced expression in BC. Notably, DNMT1 has been identified as a critical regulator of PRKCZ methylation. Conclusion Our findings elucidate the tumor-suppressive function of PRKCZ and provide insights into the molecular mechanisms underlying its downregulation in BC.

Purpose: Breast cancer (BC) is a predominant malignancy globally, surpassing lung cancer in terms of diagnostic frequency, with an escalating incidence rate in recent decades.Recent studies have investigated the role of protein kinase C zeta (PRKCZ) in diverse cellular processes in cancer biology. In this study, we evaluated the association between PRKCZ and deleterious outcomes in BC and elucidated the mechanisms underlying its expression in breast carcinoma. Methods: The correlation between PRKCZ and survival rates of patients with BC was investigated using The Cancer Genome Atlas database. The methylation status of the PRKCZ promoter was analyzed using the UALCAN database. Furthermore, we investigated the mechanisms underlying PRKCZ inactivation in BC by treatment with transferase inhibitors, methylation-specific polymerase chain reaction (PCR) analysis, western blotting, and luciferase reporter gene assays. The degree of methylation and expression levels of PRKCZ, as regulated by DNA methyltransferase 1 (DNMT1), were quantified using quantitative PCR and western blotting. Results: Our analysis revealed that decreased expression of PRKCZ in BC was significantly correlated with poor clinical prognosis. Furthermore, we observed that hypermethylation of the PRKCZ promoter contributed to its reduced expression in BC. Notably, DNMT1 has been identified as a critical regulator of PRKCZ methylation. Conclusion Our findings elucidate the tumor-suppressive function of PRKCZ and provide insights into the molecular mechanisms underlying its downregulation in BC.

Calcium polyphosphate (CPP) is a new type of degradable material for bone repair, yet it is fragile and is not so controllable in regard to degradation. For increasing biological activity and close proximity to natural bone structure, in this experiment, we chose chitosan (CS) and its derivative carboxymethyl chitosan (CMC) as the extracellular matrix structure for the organic phase. Aldehyde sodium alginate (ADA) was used as natural cross-linker. The binary (CPP/CMC) and ternary (CPP/CMC/CS) composite scaffolds were prepared by the "multiple composite-cross-linking method". The degradation laws of the two materials were investigated through the weight loss of scaffolds, the pH value of degradation solution, the compressive strength and the surface morphology characterization. The results showed that the composite scaffolds had good interface and the compressive strength increased greatly, but the organic phase of dual-phase composite scaffolds degraded quickly, while degradation controllability and mechanical properties of ternary composite scaffold were significantly improved. All the above findings show that the method of ternary complex scaffold preparation is useful for the design and preparation of bone tissue engineering materials.
Absorbable Implants ; Biocompatible Materials ; chemical synthesis ; chemistry ; Bone Cements ; chemical synthesis ; chemistry ; Calcium Phosphates ; chemistry ; Chitosan ; chemistry ; Humans ; Tissue Engineering ; Tissue Scaffolds ; chemistry

Porous calcium polyphosphate (CPP) has shown promise of tissue engineered implant application because of the biocompatibility and biodegradation. CPP with different polymerization degree were prepared by controlling the calcining time, and its polymerization degree could be calculated by developed method in this paper. Different crystal types CPP were prepared by quenching from the melt and crystallization of amorphous CPP. From the in vitro degradation, carried out in Tris-HCl buffer, the degradation velocity of CPP was controllable. The weight loss of CPP with different polymerization degrees and crystal types were different. With the increasing of polymerization degree, the weight loss during the degradation was decreasing, contrarily the strength of CPP was increasing. The amorphous CPP could degrade completely in 17 days while gamma-CPP do completely in 25 days. The degradation velocity beta-CPP and alpha-CPP was slower than gamma-CPP and the weight loss was about 12% and 5% respectively. The results of this study indicate that CPP have potential applications for bone tissue engineering as inorganic polymeric biomaterials.
Absorbable Implants ; Biocompatible Materials ; chemistry ; Bone Substitutes ; chemistry ; Calcium Phosphates ; chemistry ; Humans ; Tissue Engineering

OBJECTIVE: In order to meet the needs of electrophysiology outer hair cells, we investigate a method to separate outer hair cells simply and effectively. METHOD: The basal membrane was dissected combined with spiral ligament and axis of cochlea, then incubated with enzyme, and then mechanically triturated by micropipette. RESULT: A large number of living outer hair cells were obtained. Of 80% cells could keep good condition in 6 hours. CONCLUSION If increasing the enzyme concentration slightly and the large part of cochlea without outer bone was enzymes, we can get living outer hair cells easily.
Animals ; Cell Separation ; methods ; Cochlea ; cytology ; Guinea Pigs ; Hair Cells, Auditory ; cytology