Lin Feng-Huei

Sintered porous DP-bioactive glass and hydroxyapatite as bone substitute.

Abstract There is extensive experimental and surgical experience with the use of bone tissue to fill defects in the skeleton, to bridge non-union sites, and to pack defects in bone created from cyst curettage. DP-bioactive glass with a chemical composition of Na 2 O 8.4%, SiO 2 39.6%, P 2 0 5 12% and CaO 40% has been reported as an alternative bone substitute of high mechanical strength, good biocompatibility and which has a tight bond with living tissue. The bonding layer between DP-bioactive glass and bone tissue was considered to be formed by dissolution of calcium and phosphate ions from the DP-bioactive glass into the surrounding body fluids. The biological hydroxyapatite was suspected to deposit directly onto the bonding layer. In order to confirm the interaction between the DP-bioactive glass and bone tissue, the developed bioactive glass was implanted into rabbit femur condyle for 2–32 weeks. The histological evaluation of DP-bioactive glass as a bone substitute was also investigated in the study. Porous hydroxyapatite bioceramic was used in the control group and the results were compared with those of DP-bioactive glass. The interface between the DP-bioactive glass and bone tissue examined with SEM-EPMA showed that the bioactive glass formed a reaction layer on the surface within 2 weeks after operation and formed a direct bond with natural bone. The elements contained in the bioactive glass apparently interdiffuse with the living bone and biological hydroxyapatite deposited onto the diffusion area, which was proved by EPMA and TEM. After implantation for over 8 weeks, the DP-bioactive glass was gradually biodegraded and absorbed by the living bone. Histological examination using the optical microscope showed that osteocytes grow into the inside of the DP-bioactive glass and the bioactive glass would be expected to be a part of bone. Biomaterials (1994) 15 , (13) 1087–1098

MWCNT-Fe3O4-based immuno-PCR for the early screening of nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is the most prevalent form of malignancy in southeast China and its development is meticulously related to EBV pathogenesis. The current screening techniques are unsatisfactory in terms of the sensitivity and hence most of the NPC patients are diagnosed at an advanced stage. Herein, we report the multi-walled carbon nanotubes (MWCNTs) combined with iron oxide nanoparticles as a sensing surface for the early screening of nasopharyngeal carcinoma (NPC) by immuno-PCR (iPCR). The MWCNT-Fe3O4 nanocomposite was characterized by Fourier transform infrared spectra (FTIR), Raman spectra, X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM). The characterization techniques had confirmed the successful formation of MWCNT-Fe3O4 nanocomposites. The MWCNT-Fe3O4-based iPCR was effectively tested for the quantification of anti-EBV antibodies in human serum and the limit of detection (LOD) was compared with ELISA. The limit of detection by iPCR was valid until 1:10,000,000 fold dilution of NPC(+ve) human serum, whereas ELISA can detect the anti-EBV antibodies in human serum up to 1:100,000 fold dilution. The MWCNT-Fe3O4 offers an excellent surface area for the antigen-antibody binding and hence greater sensitivity was achieved.