OBJECTIVES To develop a 3-dimensional carrier system for subretinal transplantation of human fetal retinal pigment epithelial (HFRPE) cells and to assess their growth pattern in the rabbit subretinal space. METHODS After a standard 3-port vitrectomy, HFRPE cells grown as microspheres on cross-linked fibrinogen were introduced into the subretinal space of rabbits. The eyes were studied at 7, 1...

Novel hydrogels based on hydroxyethyl starch modified with polyethylene glycol methacrylate (HES-P(EG)₆MA) were developed as delivery system for the controlled release of proteins. Since the drug release behavior is supposed to be related to the pore structure of the hydrogel network the pore sizes were determined by cryo-SEM, which is a mild technique for imaging on a nanometer scale. The resu...

There are a number of nuclear enzymes that bind nicotinamide, thymidine or nucleotides. We use this fact to prepare affinity columns for the purification of nuclear enzymes. In particular the nuclei of eukaryotic cells have an enzyme that catalyses the synthesis of the homopolymer poly(ADP-ribose) from NAD. Isolation and partial purification has been achieved (Yamada et al., 1971 ; Ueda et al.,...

Recent developments in piconewton instrumentation allow the manipulation of single molecules and measurements of intermolecular as well as intramolecular forces. Dextran filaments linked to a gold surface were probed with the atomic force microscope tip by vertical stretching. At low forces the deformation of dextran was found to be dominated by entropic forces and can be described by the Lange...

The effects on the circulation of limited normovolaemic haemodilution with dextran 70 and subsequent haemorrhage to a mean arterial pressure of 60 mm Hg were studied with isotope-labelled microspheres in the dog. Following haemodilution, cardiac output, stroke volume and systemic oxygen transport increased. The distribution of oxygen to the heart, liver (hepatic artery), spleen and carcass (mai...

The purpose of the current study was to determine the effects of the introduction of polysaccharide chains onto the molecular surface of buckwheat proteins on buckwheat protein surface functionality. The whole buckwheat protein fraction (WBP) was prepared using 50 mM phosphate buffer (pH 7.5) containing 0.5 M NaCl and covalently linked with 6 kDa, 17.5 kDa, 40 kDa, 70 kDa, or 200 kDa dextran by...

Porous hollow glass microspheres have many uses, including encapsulation of active materials. In this paper a fast and facile method for fabricating porous hollow glass-microspheres was demonstrated by etching them using dilute hydrofluoric acid. Then, a highly reactive amine was infiltrated into the etched glass microspheres. Scanning electron microscopy was conducted for the hollow glass micr...

Mice lacking the V(alpha(1,3) (h gamma1)-gene do not produce a gamma1 anti-alpha(1,3) dextran response. However, on hyperimmunization some strains mount a kappa-anti-alpha(1,3) dextran response, whereas other remain nonresponder. Responsiveness in dominant. The kappa-anti-alpha(1,3) response difference is linked to the Ly-3 locus on chromosone 6 and is likely the result of a structural Vkappa-g...

Microspheres constitute an important part of novel drug delivery system by virtue of their small size and efficient carrier capacity. Due to their short residence time, bioadhesive characteristics can be coupled to microspheres to develop mucoadhesive microspheres. Bioadhesion can be defined as the state in which two materials, at least one of which is biological in nature, are held together fo...