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Preserved two-photon optical properties of hydrophilic proteins-conjugated quantum dots
摘要： Nonlinear optical properties of colloidal CdSe quantum dots conjugated with proteins were investigated in a wide spectral range with the two-photon excited emission technique using a tunable femtosecond laser system in the range from 700 to 1000 nm. The most signi?cant value of the two-photon absorption cross section σ2 for 2.9 nm size hydrophilic CdSe quantum dot was equal to 4 505 GM, while the two-photon excitation action cross section σ2·QY was found to be 0.101 GM at 900 nm. The nonlinear absorption properties are present as appropriate cross sections normalized per molecular weight which allows comparison of the nonlinear properties of the studied quantum dots with various nanosystems or organic dyes. The properties of these proteins covering hydrophilic colloidal quantum dots can be potentially useful for nonlinear bioimaging.
关键词： Hydrophilization,Semiconducting quantum dots,Nonlinear optical properties,Nanophotonics,Proteins
更新于2025-11-20 15:33:11
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Osteoblast Response to Different UVA-Activated Anatase Implant Coatings
摘要： The “activation” of titanium implants by UV-irradiation is reported to enhance osseointegration in vitro as well as in vivo. Anatase-enriched titanium oxide surfaces enable, via photocatalysis, a chairside “activation” of implants by short-term UVA (382 nm) irradiation. The potentially improved clinical performance of these modified surfaces depends not only on the achieved photocatalytic activity, but also on the effects caused by the micro- and nano-structure of the respective surface modification. In this study, three differently manufactured anatase-coated titanium surfaces are characterized regarding surface characteristics, photocatalytic efficiency, and their ability to promote proliferation and differentiation of osteoblasts in comparison to conventional sandblasted (S) and blasted/etched (S/A) titanium implant surfaces. Anatase surfaces are manufactured by suspension plasma spraying (SPS), precursor-based liquid film coating (PLC), and physical vapor deposition (PVD). The tested surfaces exhibit significantly different surface morphologies and anatase/rutile ratios. UVA-irradiation of samples prior to cell seeding leads to significantly improved cell proliferation and surface coverage. UVA-treatment also leads to a generally enhanced osteoblastic differentiation of cells on all anatase-coated surfaces. The anatase-enriched titanium surface modifications promote different aspects of osteoblast reactions, suggesting that the “activation” of anatase-coated titanium implants by UVA treatment is a promising chairside procedure for dental implant optimization.
关键词： anatase,osteoblasts,titanium implant activation,hydrophilization,photocatalysis
更新于2025-09-04 15:30:14