Biomedical subjects
Publications and source records attributed to E Santucci.
Bile acids have been absorbed on a microporous polypropylene membrane and the diffusion of ionic and non-ionic compounds through the barriers obtained has been studied at different pH values. Results indicate that permeation rates are affected by environmental pH conditions and an explanation of this behaviour is proposed. This study represents an approach for a pH-controlled drug delivery system.
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The diffusion of model molecules from water dispersions of ethylenevinyl-N,N-diethylglycinate copolymer microfibers has been studied in different conditions. The influence of pH on diffusion rate has been related to water association and swelling effects following structural transitions induced in the copolymer by the acidic medium, rather than to difference in binding of the diffusing species to the macromolecule.
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A new polymeric film, ethylene-vinyl-NN-diethylglycinate random copolymer, has been studied to evaluate possible applications of such a material to produce controlled release dosage forms. Protonation of the substituted amino groups took place to different extents according to environmental pH conditions. The polymeric film proved to be permeable only to uncharged species, the rate of diffusion of which increased with the increasing charge of the membrane. This effect might be related to strong polymer-proton interactions affecting structure and transport properties of the film and enhancing the solvation process. The charged form of a number of barbituric acid derivatives did not diffuse through the membrane. The uncharged forms permeated the polymeric sheeting at rates consistent with their partition coefficients and which increased with the increasing charge of the polymer.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The Authors analyze the role of microsurgery in the treatment of chronic obstructive arteriopathies. In accordance with their results, they stress the usefulness of the microtechniques in the rescue of ischaemic limbs due to distal occlusion, and how these procedures are less dangerous than amputation, even though results are not long lasting.
By means of in vitro experiments, performed with a three compartment diffusion cell, we show how the presence of surfactants, often present in the formulation of dentifrices and mouthrinses, may affect the availability of calcium and its permeation rate through the proteic layer covering dental enamel (acquired pellicle). Mucin was the protein used to simulate the pellicle. Experiments were performed at different surfactant concentrations (i.s. below and above CMC) and also in the presence of fluoride ions that are capable of enhancing enamel remineralization. The mechanisms involved, mainly related to the interaction of surfactant monomers with the model protein, are discussed in this paper.