Investigation of in vitro bioactivity, and osteoblast and angiogenic activity of spray-dried boron-doped 58S bioactive glass microspheres.

Bioactive glass is a potential biomaterial for bone reconstruction owing to its superior bioactivity and non-toxicity. Yet, the absence of a circulatory system to carry waste and nutrients is a key issue with biomaterials implanted in the body. Thus the development of functional and vascularized new tissue requires the development of angiogenesis, which involves the formation of new blood vessels. Based on this perspective, we aimed to fabricate boron-doped 58S bioactive glass microspheres using the spray drying method, which could offer great flowability, controllable morphology, and narrow size distribution. Characterization of particle morphology and elemental composition were examined using scanning electron microscopy along with energy dispersive spectroscopy, respectively. To evaluate the effect of the boron dopant on in vitro bioactivity, X-ray diffraction and Fourier transform infrared spectroscopy were employed, while MC3T3-E1 osteoblast cells and BAOEC endothelial cells were used to assess the in vitro osteoblast and angiogenic activities, respectively. Finally, the results showed that two distinct morphologies, smooth and concave spheres, were found, with discussion of the corresponding formation mechanism. In addition, positive effects of the boron dopant were demonstrated on the in vitro bioactivity, and osteoblast and angiogenic activity when compared to the un-doped BG specimen.

Assessment of resident doses near nuclear power plants in Taiwan for epidemiology study.

Dose assessments were required for the epidemiological study of residents living near nuclear power plants. In the present work, environmental pathway models have been applied to estimate radiation doses to residents living near the nuclear power plants in Taiwan. Best estimates of doses were made for residents by their age groups in different compass sectors centered at the nuclear power plants. In each sector, radiation doses were assessed using the averaged environmental, consumption and lifestyle data. For epidemiological analyses of cancer risks in different organs or tissues, individual organ absorbed doses were assessed for both the airborne and waterborne effluent releases. Such assessments were performed based on the historic data, including measured effluent releases, detected meteorological parameters, and surveyed data on the production and consumption of local agricultural, fishery and livestock products, etc. Exposure pathways consisted of the external irradiations from air submersion, ground deposition and water immersion plus the internal irradiations from inhalation and ingestion. Age-dependent annual intakes and occupancy time were locally surveyed. Dose conversion coefficients were taken from published data after International Commission on Radiological Protection Publication 60. Annual doses and cumulated doses during residence were assessed and examined for their dependence on age, organ and compass sector.