PubMed · 10770324
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A Ceriello, E Motz, D Giugliano. 2000-04-08. Hypertension and ascorbic acid.. https://doi.org/10.1016/s0140-6736(05)74700-0
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The idea of using polymeric nanoparticles as drug carriers is receiving an increasing amount of attention both in academia and industry, Nanoparticles have a number of potential applications in protein, drug and vaccine delivery, as well as gene therapy applications. In this article, we focus on this unique drug delivery technology as a method to control the release rate of substances, not only for protein delivery but also for delivering an experimental vaccine immunogen. Nanoparticles were assembled on the basis of ionic interaction between water-soluble polymers so that the resulting particles were stable in physiologic media. Among the typical polymers used to assemble nanoparticles, different polysaccharides, natural amines, and poly-amines were investigated. The entrapped substances tested included a protein and antigens. Polydextran aldehyde was incorporated into the particle core, to enable physiologic cross-linking as a method to control permeability. This resulted in long-term retention of substances that would otherwise rapidly leak out of the nanoparticles. Results of cross-linking experiments clearly demonstrated that the release rate could be substantially reduced, depending on the degree of cross-linking. For vaccine antigen delivery tests, we measured an antibody production after subcutaneous and oral administration. The data indicated that only the cross-linked antigen was immunogenic when the oral route of administration was used. The data presented in this article address primarily the utility of nanoparticulates for oral delivery of vaccine antigen.
Genaconazole (SCH 39304) is a potent triazole antifungal agent that is active both orally and topically. Genaconazole is a racemic mixture which contains 50% of the RR (SCH 42427) and 50% of the SS (SCH 42426) enantiomers. The RR isomer accounts for most of the antifungal activity of genaconazole. Serum concentrations of the RR and SS enantiomers were analyzed by a chiral HPLC method which involved extraction of serum with organic solvent followed by separation on a Cyclobond I column and quantification by UV absorbance at 205 nm. The bioavailability and pharmacokinetic profiles of the two enantiomers after oral administration of the racemate (genaconazole) were very similar in cynomolgus monkeys. In rats following dosing with genaconazole, the RR enantiomer had a lower C(max) and a longer t(1/2) than the SS enantiomer, while the AUC(I) values of the two enantiomers were similar. Based on chiral HPLC analysis, there was no evidence for the inversion of the RR to the SR isomer, or of the SS to the SR isomer, indicating that there was no chiral inversion of the RR or SS enantiomers in either species. Genaconazole at 20 mg/kg and the RR (SCH 42427) enantiomer at 10 mg/kg had very similar serum concentration-time profiles and C(max), AUC(I), and t(1/2) values for the RR enantiomer in both rats and monkeys, indicating that the two treatments were equivalent with respect to the bioavailability of the RR enantiomer.
A plant expression cassette system was engineered to efficiently target proteins to the default secretory pathway, allowing the expression of DNA inserts in three frames as fusion proteins containing a synthetic tobacco calreticulin cleavable signal peptide sequence, with the advantage of producing the recombinant proteins by phytosecretion. As one approach to develop a vaccine to enteropathogenic Escherichia coli (EPEC) infection, the oral immunogenicity of phytosecreted BfpA, the structural subunit A of the bundle-forming pilus, expressed at high levels (7.7% of soluble protein) in transgenic tobacco tissues, was demonstrated in BALB/c mice by the induction and detection of fecal anti-BfpA antibodies.