ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2003-01-01
    Description: Both Fourier Transform Infrared (FTIR) and Raman spectroscopy have been applied to thein vitrocharacterisation of biomaterials, mainly surface reactions leading to the formation of a biologically active hydroxycarbonate apatite (HCA) layer on the sample surface when immersed in simulated body fluids (SBF). The HCA layer indicates the degree of bioactivity of the sample, because it leads to a strong bond between the biomaterial and living tissue. Reflection measurements using FTIR allow quick, non-destructive detection of the HCA layer for solid and powder samples. Due to the low Raman scattering efficiency and low absorption of water in the visible-near infrared region, Raman micro-spectroscopy was successfully used for thein situcharacterisation of 20 and 40µm diameter 45S5 Bioglass®fibres. Thein situcapabilities of the Raman micro-spectrometer have also been extended to the characterisation of living cells attached on bioinert silica and bioactive 45S5 Bioglass®and 58S substrates. Using a high power 785 nm laser, living cells in physiological conditions can be real-time sampled over long periods of time without inducing cell damage and with good signal strength. Cell death can be monitored because it proved to induce strong changes in the Raman signature in the spectral regions 1000–1150 cm–1and 1550–1650 cm–1.
    Print ISSN: 0712-4813
    Electronic ISSN: 1875-922X
    Topics: Physics
    Published by IOS Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2002-01-01
    Description: We report the first Raman spectra of individual living and dead cells (MLE-12 line) cultured on bioinert standard poly-L-lysine coated fused silica and on bioactive 45S5 Bioglass®measured at 785 nm laser excitation. At this excitation wavelength no damage was induced to the cells even after 40 minutes irradiation at 115 mW power, as indicated by cell morphology observation and trypan blue viability test. We show that shorter wavelength lasers, 488 nm and 514 nm, cannot be used because they induce damage to the cells at very low laser powers (5 mW) and short irradiation times (5–20 minutes). The most important differences between the spectra of living and dead cells are in the 1530–1700 cm−1range, where the dead cells have strong peaks at 1578 cm−1and 1607 cm−1. Other differences occur around the DNA peak at 1094 cm−1. Our study establishes the feasibility of using the 785 nm laser for anin situreal-time non-invasive method to follow biological events (proliferation, differentiation, cell death, etc.) within individual cells cultured on bioactive scaffolds in their physiologic environment over long periods of time.
    Print ISSN: 0712-4813
    Electronic ISSN: 1875-922X
    Topics: Physics
    Published by IOS Press
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1432-0827
    Keywords: Key words: Bioactive glass-ceramics — Tissue engineering — Osteoblasts — Osteogenesis.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Notes: Abstract. We investigated the concept of using bioactive substrates as templates for in vitro synthesis of bone tissue for transplantation by assessing the osteogenic potential of a melt-derived bioactive glass ceramic (Bioglass® 45S5) in vitro. Bioactive glass ceramic and bioinert (plastic) substrates were seeded with human primary osteoblasts and evaluated after 2, 6, and 12 days. Flow cytometric analysis of the cell cycle suggested that the bioactive glass-ceramic substrate induced osteoblast proliferation, as indicated by increased cell populations in both S (DNA synthesis) and G2/M (mitosis) phases of the cell cycle. Biochemical analysis of the osteoblast differentiation markers alkaline phosphatase (ALP) and osteocalcin indicated that the bioactive glass-ceramic substrate augmented osteoblast commitment and selection of a mature osteoblastic phenotype. Scanning electron microscopic observations of discrete bone nodules over the surface of the bioactive material, from day 6 onward, further supported this notion. A combination of fluorescence, confocal, transmission electron microscopy, and X-ray microprobe (SEM-EDAX) examinations revealed that the nodules were made of cell aggregates which produced mineralized collagenous matrix. Control substrates did not exhibit mineralized nodule formation at any point studied up to 12 days. In conclusion, this study shows that Bioglass 45S5 has the ability to stimulate the growth and osteogenic differentiation of human primary osteoblasts. These findings have potential applications for tissue engineering where this bioactive glass substrate could be used as a template for the formation of bioengineered bone tissue.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Materials research innovations 3 (2000), S. 313-323 
    ISSN: 1433-075X
    Keywords: Keywords Glass ; Cell cycle ; Genes ; Bone ; Bioactive materials ; Osteogenesis ; Prostheses ; Omplants ; Ageing ; Osteoblasts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  Many of the present generation biomaterials are still based upon the early concept that implantable materials should be bioinert and therefore designed to evoke minimal tissue response, if none. However, a growing body of clinical data demonstrates that the long survivability of these materials is hampered by high rates of failure, which is primarily attributed to interfacial instability. It has therefore become understood that this approach is not optimal. Modern approaches implicate the use of biomaterials that can actively interact with tissues and induce their intrinsic repair and regenerative potential. This involves control over the cell cycle, the molecular framework that controls cell proliferation and differentiation. Class A bioactive glass-ceramic materials were the first materials shown to endorse these properties and, depending upon the rate of resorption and release of ions, can create chemical gradients with specific biological actions over cells and tissues. Optimising this bioactive regenerative capacity of Bioactive glass-ceramics offers great hope for producing biomaterials that can stimulate growth, repair, and regeneration of any human tissue.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...