A preliminary study of using maleic anhydride copolymer for protein binding has been carried out. The polymeric films were prepared by compression of the purified resin and annealing the film to induce efficient back ...A preliminary study of using maleic anhydride copolymer for protein binding has been carried out. The polymeric films were prepared by compression of the purified resin and annealing the film to induce efficient back formation of the anhydride groups. The properties of the film surface were analyzed by attenuated total reflection Fourier transforms infrared spectroscopy and water contact angle measurements. The protein content was determined by Bradford assay. To obtain optimum conditions, immersion time for protein binding was examined. Results revealed that proteins can be successfully immobilized onto the film surface via covalent linkage. The efficiency of the covalent binding of the extractable protein to maleic anhydride-polyethylene film was estimated at 69.87 ug/cm2, although the film had low anhydride content （3%） on the surface.展开更多
Photoluminescent silicon nanoparticles 1-2 nm in size were synthesized by a wet chemical procedure and derivatized with propylamine （NH2SiNP）. Surface NH2 groups were used as linkers for additional poly（ethylene gl...Photoluminescent silicon nanoparticles 1-2 nm in size were synthesized by a wet chemical procedure and derivatized with propylamine （NH2SiNP）. Surface NH2 groups were used as linkers for additional poly（ethylene glycol） （PEG） and folic acid （Fo） attachment （PEG-NHSiNP and Fo-NHSiNP, respectively） to enable efficient targeting of the particles to tumors and inflammatory sites. The particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ζ potential, dynamic light scattering, and time-resolved anisotropy. The photophysical properties and photosensitizing capacity of the particles and their interaction with proteins was dependent on the nature of the attached molecules. While PEG attachment did not alter the photophysical behavior of NH2SiNP, the attachment of Fo diminished particle photoluminescence. Particles retained the capacity for 1O2 generation; however, efficient 1O2 quenching by the attached surface groups may be a drawback when using these particles as 1O2photosensitizers. In addition, Fo attachment provided particles with the capacity to generate the superoxide anion radical （O2-）. The particles were able to bind tryptophan residues of bovine serum albumin （BSA） within quenching distances. NH2SiNP and PEG-NHSLNP ground state complexes with BSA showed binding constants of （3.1 ± 0.3） × 10^4 and （1.3 ±0.4） × 10^3 M-1, respectively. The lower value observed for PEG-NHSiNP complexes indicates that surface PEGylation leads to a reduction in protein adsorption, which is required to prevent opsonization. An increase in particle luminescence upon BSA binding was attributed to the hydrophobic environment generated by the protein. NH2SiNP-BSA complexes were also capable of resonance energy transfer.展开更多
文摘A preliminary study of using maleic anhydride copolymer for protein binding has been carried out. The polymeric films were prepared by compression of the purified resin and annealing the film to induce efficient back formation of the anhydride groups. The properties of the film surface were analyzed by attenuated total reflection Fourier transforms infrared spectroscopy and water contact angle measurements. The protein content was determined by Bradford assay. To obtain optimum conditions, immersion time for protein binding was examined. Results revealed that proteins can be successfully immobilized onto the film surface via covalent linkage. The efficiency of the covalent binding of the extractable protein to maleic anhydride-polyethylene film was estimated at 69.87 ug/cm2, although the film had low anhydride content （3%） on the surface.
文摘Photoluminescent silicon nanoparticles 1-2 nm in size were synthesized by a wet chemical procedure and derivatized with propylamine （NH2SiNP）. Surface NH2 groups were used as linkers for additional poly（ethylene glycol） （PEG） and folic acid （Fo） attachment （PEG-NHSiNP and Fo-NHSiNP, respectively） to enable efficient targeting of the particles to tumors and inflammatory sites. The particles were characterized by transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ζ potential, dynamic light scattering, and time-resolved anisotropy. The photophysical properties and photosensitizing capacity of the particles and their interaction with proteins was dependent on the nature of the attached molecules. While PEG attachment did not alter the photophysical behavior of NH2SiNP, the attachment of Fo diminished particle photoluminescence. Particles retained the capacity for 1O2 generation; however, efficient 1O2 quenching by the attached surface groups may be a drawback when using these particles as 1O2photosensitizers. In addition, Fo attachment provided particles with the capacity to generate the superoxide anion radical （O2-）. The particles were able to bind tryptophan residues of bovine serum albumin （BSA） within quenching distances. NH2SiNP and PEG-NHSLNP ground state complexes with BSA showed binding constants of （3.1 ± 0.3） × 10^4 and （1.3 ±0.4） × 10^3 M-1, respectively. The lower value observed for PEG-NHSiNP complexes indicates that surface PEGylation leads to a reduction in protein adsorption, which is required to prevent opsonization. An increase in particle luminescence upon BSA binding was attributed to the hydrophobic environment generated by the protein. NH2SiNP-BSA complexes were also capable of resonance energy transfer.
