Fabrication of Dexamethasone-Loaded Dual-Metal-Organic Frameworks on Polyetheretherketone Implants with Bacteriostasis and Angiogenesis Properties for Promoting Bone Regeneration.

Polyetheretherketone (PEEK) is a biocompatible polymer, but its clinical application is largely limited due to its inert surface. To solve this problem, a multifunctional PEEK implant is urgently fabricated. In this work, a dual-metal-organic framework (Zn-Mg-MOF74) coating is bonded to PEEK using a mussel-inspired polydopamine interlayer to prepare the coating, and then, dexamethasone (DEX) is loaded on the coating surface. The PEEK surface with the multifunctional coating provides superior hydrophilicity and favorable stability and forms an alkaline microenvironment when Mg2+, Zn2+, 2,5-dihydroxyterephthalic acid, and DEX are released due to the coating degradation. In vitro results showed that the multifunctional coating has strong antibacterial ability against both Escherichia coli and Staphylococcus aureus; it also improves human umbilical vein endothelial cell angiogenic ability and enhances rat bone marrow mesenchymal stem cell osteogenic differentiation activity. Furthermore, the in vivo rat subcutaneous infection model, chicken chorioallantoic membrane model, and rat femoral drilling model verify that the PEEK implant coated with the multifunctional coating has strong antibacterial and angiogenic ability and promotes the formation of new bone around the implant with a stronger bone-implant interface. Our findings indicate that DEX loaded on the Zn-Mg-MOF74 coating-modified PEEK implant with bacteriostasis, angiogenesis, and osteogenesis properties has great clinical application potential as bone graft materials.

Assembly of MXene/PP Separator and Its Enhancement for Ni-Rich LiNi0.8Co0.1Mn0.1O2 Electrochemical Performance.

In this work, a few-layer MXene is prepared and sprinkled on a commercial polypropylene (PP) separator by a facile spraying method to enhance the electrochemistry of the Ni-rich LiNi0.8Co0.1Mn0.1O2 (NCM811) cathode. Scanning electron microscope (SEM) and X-ray diffraction (XRD) are used to characterize the morphology and structure of MXene. Fourier transform infrared spectroscopy (FT-IR) and a contact angle tester are used to measure the bond structure and surface wettability PP and MXene/PP separator. The effect of the MXene/PP separator on the electrochemical performance of ternary NCM811 material is tested by an electrochemical workstation. The results show that the two-dimensional MXene material could improve the wettability of the separator to the electrolyte and greatly enhance the electrochemical properties of the NCM811 cathode. During 0.5 C current density cycling, the Li/NCM811 cell with MXene/PP separator remains at 166.2 mAh/g after the 100 cycles with ~90.7% retention. The Rct of MXene/PP cell is measured to be ~28.0 Ω. Combining all analyses results related to MXene/PP separator, the strategy by spraying the MXene on commercial PP is considered as a simple, convenient, and effective way to improve the electrochemical performance of the Ni-rich NCM811 cathode and it is expected to achieve large-scale in high-performance lithium-ion batteries in the near future.

A zwitterionic serine modified chitosan derivative for improving protein stability and activity.

A zwitterionic phosphoryldiserine (PDS)- chitosan conjugate was synthesized via Atherton-Todd reaction, and its degree of substitution of PDS and structure were characterized by 1H and 31P NMR spectra, ICP, FTIR and XRD. Thermal analysis confirmed that there existed the freezing bound water surrounding PDS-chitosan due to the introduction of zwitterionic PDS groups onto chitosan backbone. In vitro cytotoxicity and hemolysis assay demonstrated that PDS-chitosan had excellent cell compatibility. UV adsorption and fluorescence spectra revealed that the model protein, bovine serum albumin (BSA) tended to keep its native conformation and showed better thermal stability in aqueous media in the presence of PDS-chitosan. We also found that the esterase-like activity of BSA could be enhanced by low concentration of PDS-chitosan (CBSA = 0.33 mg/mL, CPDS-chitosan = 0.0625 and 0.125 mg/mL, pH = 7.4, T = 25 °C). The results indicated that zwitterionic PDS-chitosan showed great potential for maintaining protein function in biomedical applications.

Ultrasound combined with computed tomography in pancreatic cancer.

PURPOSE: To investigate the diagnostic value of ultrasound combined with computed tomography (CT) in pancreatic cancer. METHODS: 312 patients with pancreatic lesions treated in the Affiliated Hospital of Qingdao University were retrospectively analyzed, including 217 patients definitely diagnosed with pancreatic cancer and 95 patients diagnosed with pancreatitis. A hundred and one patients with ultrasonic diagnosis were enrolled into the ultrasound group, 98 patients with CT diagnosis were enrolled into CT group, and 113 patients undergoing ultrasound combined with CT diagnosis were enrolled into combined group. The diagnostic value of the three examination methods in pancreatic cancer was compared and analyzed. RESULTS: The sensitivity, accuracy and negative prognostic value in the combined group were higher than those in ultrasound group and CT group (p<0.05), but the missed diagnosis rate was lower than those in ultrasound group and CT group (p<0.05). In the combined group, the sensitivity was higher than those in the ultrasound group and the CT group, the accuracy and negative predictive value were higher than those in the ultrasound group, and the missed diagnosis rate was lower than those in the ultrasound group and the CT group, displaying statistically significant differences (p<0.05). CONCLUSION: Ultrasound combined with CT can make up for the deficiency of each other and effectively improve the predictive value in the diagnosis of pancreatic cancer, which can be used as an effective examination method in the diagnosis of this disease.

CT combined with tumor markers in the diagnosis and prognosis of hepatocellular carcinoma.

PURPOSE: To investigate the application values of CT combined with tumor markers (TM) in the diagnosis and prognosis of hepatocellular carcinoma (HCC). METHODS: 62 HCC patients were selected as the study group and all of them had undergone hepatectomy. In addition, 40 healthy subjects composed the control group. Blood samples were collected preoperatively from the subjects of the study group, and serum alpha fetoprotein (AFP), carbohydrate antigen 19-9 (CA19-9) and carcinoembryonic antigen (CEA) levels were determined by radioimmunoassay. The correlation between serum TM levels and clinicopathological features was investigated by pathological examination. The imaging features of HCC were explored by spiral CT plain scanning and enhanced scanning. The diagnostic efficiency of single detection of TM, combined detection of TMs and combined detection of TMs and CT was analyzed by receiver operating characteristic (ROC). RESULTS: The levels of serum AFP, CA19-9 and CEA in HCC patients were significantly higher than those in the control group (p<0.05). Patients with low differentiation and distant metastasis had higher levels of AFP, CA19-9 and CEA (p<0.05) compared with patients with high differentiation and no distant metastasis. There were no significant differences in TM levels in HCC patients with different age, gender and clinical stages (p>0.05). The ROC analysis showed that the single detection of serum AFP, CEA or CA19-9 had lower specificity and sensitivity compared with the combined detection of the three TMs (p<0.05). The combined CT examination could achieve a specificity of 95.71% and a sensitivity of 87.47%, superior to the combined detection of the TMs (p<0.05). Eight HCC patients relapsed within 6 months after operation. Compared with those before operation, the levels of serum AFP, CA19-9 and CEA in the relapsed patients were increased significantly, and the TM levels were higher than those in patients without relapse (p<0.05). CONCLUSIONS: The detection of serum AFP, CA19-9 and CEA combined with CT can overcome the deficiency of single detection, avoid misdiagnosis and missed diagnosis, and increase significantly the positive detection rate of HCC.