Osteoinductive nanohydroxyapatite bone substitute prepared via in situ hydrothermal transformation of cuttlefish bone.

The capacity to induce a rapid and controlled healing of bone defects is critical for a bone substitute. Previous studies have reported hydrothermal transformation (HT) of aragonite from cuttlebone (CB) to cuttlebone hydroxyapatite (CBHA). However, the biocompatibility and in vivo characteristic of CBHA have not been fully investigated. We fabricated CBHA via the in situ HT of aragonite from CB. This CBHA exhibited a highly porous structure and nanoscaled surface morphology with a significantly higher protein adsorption rate than CB. Marrow mesenchymal stem cells (MSCs) were seeded and cultured on the CBHA and CB to evaluate their influence on cell proliferation and differentiation. According to scanning electronic microscopy observation and MTT assay, the MSCs adhered and proliferated well on both the CBHA and CB. Compared with the cells on the CB, the MSCs on CBHA exhibited enhanced alkaline phosphatase activity and osteocalcin levels after 13 days of culture. In vivo testing revealed that CBHA could induce ectopic bone formation after implantation, while no bone formation being observed in the CB. These findings demonstrated that a nanoscaled and osteoinductive bone substitute could be produced by hydrothermally transforming an aragonite of CB into a hydroxyapatite.

Cultured cortical astrocytes of newborn rat can be infected by Hantaviruses / 中华传染病杂志

Objective To confirm that astrocytes from cerebral cortex of newborn rat can be the target cells of Hantaan virus (HTNV)and Seoul virus (SEOV)infection and to observe changes of astrocytes after different infection time. Methods Astrocytes were prepared from cerebral cortex of newborn rat, and then infected with HTNV and SEOV. The established virus infections were confirmed by detection of virus nucleocapsid protein (NP) and S segment RNA in astrocytes using double-label immunofluoreseence, Western-blot and reverse transcriptase-polymerase chain reaction (RT-PCR). Results The astrocytes from cerebral cortex of newborn rat were cultured successfully in vitro, which could be infected by HTNV and SEOV. The number of infected astrocytes and the virus titer in the infected astrocytes kept on increasing along with the extended infection duration. Conclusions Astrocytes from cerebral cortex of newborn rat are the target cells for HTNV and SEOV infection. Then establishment of in vitro cultured astrocytes model for Hantaviruses infection will be helpful for the study on the pathogenesis of hemorrhagic fever with renal syndrome.