The acceleration of titanium implant osseointegration by low intensity pulsed ultrasound: an experimental study in rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To establish an animal model of titanium implant and to investigate the effects of low intensity pulsed ultrasound (LIPUS) on the implant osseointegration.</p><p><b>METHODS</b>Twenty-four female Sprague Dawley (SD) rats were used. Titanium implants were inserted into tibia metaphysis bilaterally in each SD rat. Since the second day following implant surgery, LIPUS stimulation were carried out around the implant on the right side for 20 minutes per day, and implants on the left side remain untouched as self-control. Eight rats were sacrificed and tibiae specimens were harvested on the end of the 4th, 8th, and 12th week respectively. X-ray picture, micro-CT analysis and histological sections were performed to evaluate the effects of LIPUS on the implant osseointegration.</p><p><b>RESULTS</b>Osseointegration at the interface between the implant and bone tissue was observed bilaterally. In the micro-CT histomorphometry analysis, the percentage of osseointegration (%OI) of experiment side were (45.708 ± 3.316)%, (46.231 ± 1.954)%, and (46.807 ± 1.451)% on the end of the 4th, 8th, and 12th week. Meanwhile, the %OI of control side were (43.021 ± 3.558)%, (44.272 ± 3.023)%, and (44.894 ± 4.215)% respectively. The %OI on the 4th weekend, bone volume ratio (BV/TV) on the 4th and 8th weekend, trabecular thickness (Tb. Th) and degree of anisotropy (DA) on the 8th and 12th weekend of the experiment side tibia were significantly greater than those on the control side (P < 0.05). The histological examination showed that the thickness of new bone around the implant and the bone-implant contact area was obviously greater in the LIPUS treated side compared to the control side.</p><p><b>CONCLUSIONS</b>The LIPUS therapy may accelerate the bone healing and osseointegration at the interface between titanium implant and bone, and promote remodeling of bone trabecula on the early stage.</p>

Cloning, prokaryotic expression of chicken interferon-alpha gene and study on antiviral effect of recombinant chicken interferon-alpha / 生物工程学报

The full length of chicken interferon alpha (ChIFN-alpha) gene was amplified by the polymerase chain reaction (PCR) from total liver genome of Sanhuang meat-chicken and sequenced. The amplified gene was about 582bp. The coding region for mature protein (489bp) was subcloned into pET-28a(+). The recombinant plasmid pET-28a(+)-IFNalpha was identified by enzyme digestion and DNA sequencing. Data of SDS-PAGE and Western-blot indicated that a 22kD fusion protein was expressed in the form of inclusion bodies with good immunity. The purity of inclusion bodies was above 70% and that of protein purified by nickel affinity chromatography was 95%. The recombinant protein could inhibit H9N2 avian influenza virus (H9N2 AIV) replication on chick embryo fibroblast. 2 microg of recombinant IFN-alpha could completely protect Chick embryo from H9N2 AIV infection. The recombinant IFN-alpha can also delay Newcastle disease virus (NDV) replication on chick embryo for 12 approximately 48h. Chicken administered recombinant IFN-alpha can resist the H9N2 AIV infection. The bioactivities of recombinant IFN-alpha purified by affinity chromatograph were 20 times higher than that of inclusion bodies.