Poly(vinylidene fluoride-co-chlorotrifluoroethylene) Modification via Organocatalyzed Atom Transfer Radical Polymerization.

To address the challenge of metal contamination, a "graft from" approach via organocatalyzed atom transfer radical polymerization (O-ATRP) is developed to synthesize poly(vinylidene fluoride-co-chlorotrifluoroethylene) (P(VDF-co-CTFE)) graft copolymers. N-phenylphenothiazine is utilized as a model organic photoredox catalyst for catalyzing the (co)polymerization of methyl methacrylate (MMA), methacrylate (MA), and n-butyl acrylate (BA). By employing this technique, high temporal control of polymerization and graft content are achieved. A series of P(VDF-co-CTFE)-g-PMMA, P(VDF-co-CTFE)-g-PMA, and P(VDF-co-CTFE)-g-PBA is prepared under mild conditions. The resultant graft copolymer can be used as macroinitiator to re-initiate O-ATRP to synthesize P(VDF-co-CTFE)-g-(PMMA-b-PMA), which might exhibit the potential application as novel dielectric material.

A clinical comparative study of anatomic parameters before and after total hip replacement on congenital dysplasia.

[Purpose] To study preoperative and postoperative hip circumference data of various types of congenital dysplasia of the hip treated with total hip replacement, including the femoral offset, femoral neck length, height, and hip abductor arm parameters. [Subjects and Methods] This study included seventy-eight cases of congenital dysplasia of the hip (I-III type). Furthermore, four parameters were measured, including the preoperative and postoperative femoral offset. Statistical data analysis was performed using the SPSS 13.0 software. [Results] The femoral offset was 33.3 ± 8.4 mm (preoperative) and 39.1 ± 7.1 mm (postoperative). The femoral head height was 59.5 ± 8.7 mm (preoperative) and 68.8 ± 11.0 mm (postoperative). The femoral neck length was 50.8 ± 10.8 mm (preoperative) and 61.5 ± 10.4 mm (postoperative). The hip abductor arm was 54.3 ± 9.6 mm (preoperative) 64.7 ± 10.1 mm (postoperative). The preoperative and postoperative parameters showed statistical differences. Furthermore, no significant differences were evidenced when comparing the postoperative hip parameters with the normal data parameters. [Conclusion] Total hip replacement on congenital dysplasia of the hip could lead to the rebuilt of an almost normal physiological anatomy for each hip case (type I-III).

UBR5 Significantly Correlates with Osteosarcomas Prognosis and Immune Exhaustion Characteristic in the Tumor Microenvironment.

BACKGROUND: Ubiquitin ligases (E3s) play an important role in multiple cancers. METHODS: The open-accessed expression profile and clinical information was downloaded from the TARGET database. The analysis was performed using R software. RESULTS: In this study, we comprehensively investigated the role of E3s in osteosarcomas (OS). We found that among all these E3s, UBR5 is a risk factor for OS. Considering that UBR5 has not been reported in previous studies focused on OS, we selected it for further analysis. Interestingly, we found that UBR5 had no significant effect on immune cell infiltration but a remarkable effect on immune function. Moreover, we divided the patients into "immune activation" and "immune exhaustion" types. KM survival curves indicated that the patients in the "immune exhaustion" types had a worse survival performance. Further, we identified the molecules involved in immune function and significantly correlated with UBR5. The biological enrichment analysis and prognosis model were then conducted based on these genes. Results indicated that the patients in the high-risk group had a worse survival performance, and underlying biological differences between high and low-risk patients were also explored. Ultimately, the effect pattern of UBR5 in pan-cancer was also explored. CONCLUSION: In summary, our study comprehensively explored the role of UBR5 in OS, as well as its effect on the immune microenvironment, which might be an underlying therapy target.

The Role of miR-34c-5p in Osteogenic Differentiation of Bone Marrow Mesenchymal Stem Cells.

BACKGROUND AND OBJECTIVES: Osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) plays a critical role in the success of lumbar spinal fusion with autogenous bone graft. This study aims to explore the role and specific mechanism of miR-34c-5p in osteogenic differentiation of BMSCs. METHODS AND RESULTS: Rabbit model of lumbar fusion was established by surgery. The osteogenic differentiation dataset of mesenchymal stem cells was obtained from the Gene Expression Omnibus (GEO) database, and differentially expressed miRNAs were analyzed using R language (limma package). The expressions of miR-34c-5p, miR-199a-5p, miR-324-5p, miR-361-5p, RUNX2, OCN and Bcl-2 were determined by qRT-PCR and Western blot. ELISA, Alizarin red staining and CCK-8 were used to detect the ALP content, calcium deposition and proliferation of BMSCs. The targeted binding sites between miR-34c-5p and Bcl-2 were predicted by the Target database and verified using dual-luciferase reporter assay. MiR-34c-5p expression was higher in rabbit lumbar fusion model and differentiated BMSCs than normal rabbit or BMSCs. The content of ALP and the deposition of calcium increased with the osteogenic differentiation of BMSCs. Upregulation of miR-34c-5p reduced cell proliferation and promoted ALP content, calcium deposition, RUNX2 and OCN expression compared with the control group. The effects of miR-34c-5p inhibitor were the opposite. In addition, miR-34c-5p negatively correlated with Bcl-2. Upregulation of Bcl-2 reversed the effects of miR-34c-5p on ALP content, calcium deposition, and the expressions of RUNX2 and OCN. CONCLUSIONS: miR-34c-5p could promote osteogenic differentiation and suppress proliferation of BMSCs by inhibiting Bcl-2.

Photoinduced Cu(II)-Mediated RDRP to P(VDF-co-CTFE)-g-PAN.

Photoinduced Cu(II)-mediated reversible deactivation radical polymerization (RDRP) was employed to synthesize poly(vinylidene fluoride-co-chlorotrifluoroethylene)-graft-polyacrylonitrile (P(VDF-co-CTFE)-g-PAN). The concentration of copper catalyst (CuCl2) loading was as low as 1/64 equivalent to chlorine atom in the presence of Me6-Tren under UV irradiation. The light-responsive nature of graft polymerization was confirmed by "off-on" impulsive irradiation experiments. Temporal control of the polymerization process and varied graft contents were achieved via this photoinduced Cu(II)-mediated RDRP.

Effects of adenoviral vector expressing hIGF-1 on apoptosis in nucleus pulposus cells in vitro.

The excessive apoptosis of cells of the nucleus pulposus may plays an important role in intervertebral disc (IVD) degeneration. It has been shown that the pro-inflammatory cytokine tumour necrosis factor (TNF)-α can induce disc cell apoptosis. Insulin-like growth factor (IGF)-1 can promote nucleus pulposus cell proliferation; however, whether or not IGF-1 inhibits TNF-α-induced apoptosis in the nucleus pulposus has not yet been elucidated. In this study, our objective was to create a potentially therapeutic viral vector, which could be used to achieve the enforced expression of IGF-1 in rabbit nucleus pulposus cells. Furthermore, we investigated the ability of IGF-1 to reverse TNF-α-induced apoptosis in cells of the nucleus pulposus. Isolated nucleus pulposus cells were cultured to a confluent monolayer, digested with collagenase Ⅱ and purified using trypsin and differential adhesion methods. Nucleus pulposus cells were positively identified using type Ⅱ collagen immunohistochemistry. Following transfection with adenoviral vectors engineered to overexpress recombinant human IGF-1 (Ad-hIGF-1) or TNF-α, the cells were observed under a light microscope. Terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end-labeling (TUNEL) and flow cytometry (FCM) were used to assess the rate of apoptosis. The Ad-hIGF-1 viral vector was effectively transduced into the nucleus pulposus cells and increased IGF-1 expression as confirmed by RT-PCR and western blot analysis. In the TNF-α-treated group, a large number of apoptotic cells was observed that exhibited morphological changes associated with this form of cell death. Minimal apoptosis was observed in the Ad-hIGF-1-treated group and the control group showed no obvious signs of apoptosis. TUNEL assay revealed that the rate of apoptosis in the Ad-hIGF-1 group was significantly reduced compared with the TNF-α-treated group (P<0.01). This result was confirmed using FCM. The rate of apoptosis was also significantly increased in the TNF-α-exposed cells compared with the control group (P<0.01). Our findings strongly suggest that the adenoviral vector expressing hIGF-1 can successfully infect nucleus pulposus cells in vitro and effectively enhance the expression of IGF-1. In addition, IGF-1 reversed the TNF-α -induced apoptosis of nucleus pulposus cells. Thus, Ad-hIGF-1 may be useful in the development of clinical interventions for disc degeneration.

[Effects of recombinant adenovirus vector carrying human insulin-like growth factor 1 gene on the apoptosis of nucleus pulposus cells in vitro].

OBJECTIVE: To investigate the effects of human insulin-like growth factor 1 (hIGF-1) gene transfected by recombinant adenovirus vector (Ad-hIGF-1) on the apoptosis of rabbit nucleus pulposus cells induced by tumor necrosis factor a (TNF-alpha). METHODS: The intervertebral disc nucleus pulposus were harvested from 8 healthy adult domestic rabbits (male or female, weighing 2.0-2.5 kg). The nucleus pulposus cells were isolated with collagenase II digestion and the passage 2 cells were cultured to logarithm growing period, and then they were divided into 3 groups according to culture condition: DMEM/ F12 medium containing 10% PBS, DMEM/F12 medium containing 10% PBS and 100 ng/mL TNF-alpha, and DMEM/F12 medium containing 10% PBS, 100 ng/mL TNF-alpha, and Ad-hIGF-1 (multiplicity of infection of 50) were used in control group, TNF-alpha group, and Ad-hIGF-1 group, respectively. The results of transfection by adenovirus vector carrying hIGF-1 gene were observed by fluorescent microscopy; the expression of hIGF-1 protein was detected by Western blot, hIGF-1 mRNA expression by RT-PCR, and the cell apoptosis rate by TUNEL and flow cytometry. RESULTS: Green fluorescence was observed by fluorescent microscopy in Ad-hIGF-1 group, indicating that successful cell transfection. The expressions of hIGF-1 protein and mRNA were detected in Ad-hIGF-1 group by Western blot and RT-PCR, while the control group and TNF-alpha group had no expression. The cell apoptosis rates of TNF-alpha group, Ad-hIGF-1 group, and control group were 34.24% +/- 4.60%, 6.59% +/- 1.03%, and 0.40% +/- 0.15%, respectively. The early apoptosis rates of TNF-alpha group, Ad-hIGF-1 group, and control group were 22.16% +/- 2.69%, 5.03% +/- 0.96%, and 0.49% +/- 0.05%, respectively; the late cell apoptosis rates were 13.96% +/- 4.86%, 10.68% +/- 3.42%, and 0.29% +/- 0.06%, respectively. Compared with TNF-alpha group, the cell apoptosis rates of Ad-hIGF-1 group and control group were significantly reduced (P < 0.05); the cell apoptosis rate of Ad-hIGF-1 group was significantly higher than that of control group (P < 0.05). CONCLUSION: Ad-hIGF-1 could ingibit the apoptosis of nucleus pulposus cells induced by TNF-alpha.