Oral delivery of proteins and peptides is one of the main challenges in pharmaceutical drug development. Microdevices have the possibility to protect the therapeutics until release is desired, avoiding losses by degradation. One type of microdevice is polymeric microcontainers. In this study, lysozyme is chosen as model protein and loaded into microcontainers with the permeation enhancer sodium decanoate (C10). The loaded microcontainers are sealed and functionalized by applying polymeric lids onto the cavity of the devices. The first lid is poly(lactic-co-glycolic) acid (PLGA) and on top of this either polyethylene glycol (PEG) or chitosan is applied (PLGA+PEG or PLGA+chitosan, respectively). The functionalization is evaluated in vitro for morphology, drug release, and mucoadhesive properties. These are coupled with in vitro and ex vivo studies using Caco-2 cells, Caco-2/HT29-MTX-E12 co-cultures, and porcine intestinal tissue. PLGA+chitosan shows slower release compared to PLGA+PEG or only PLGA in buffer and the transport of lysozyme across cell cultures is not enhanced compared to the bulk powder. Microcontainers coated with chitosan or PEG demonstrate a three times stronger adhesion during ex vivo mucoadhesion studies compared to samples without coatings. Altogether, functionalized microcontainers with mucoadhesive properties and tunable release for oral protein delivery are developed and characterized.

Soil organic matter forms complexes with metals by ionexchange, surface adsorption, chelation, and complex coagulation and peptization reactions. Little is known concerning the nature of the ligands in polymeric components of soil organic matter which chelate metals, but carboxyl, hydroxy, and amide groups are probably involved. A number of low molecular weight compounds capable of chelating metals have been isolated from soils.Metallo-organic matter complexes must be identified journal paper No. 15-62 of the Ohio Agr. Exp. Sta., published

Adsorption experiments were conducted by mixing NaCl‐kaolinite and C14‐labelled hydrolyzed polyacrylonitrile (HPAN) in water solutions of various electrolytes. An increase in the concentration of electrolyte caused an increase in extent of HPAN adsorption, the effect apparently being due to reduction of electrostatic repulsion between HPAN and kaolinite and reduction in size of the HPAN coil. Divalent cations, especially the transition metals capable of being complexed, were more effective than univalent cations. Maximum adsorption took place in the presence of H+ ions. Anions capable of complexing lattice aluminum and/or decomposing the clay crystal reduced adsorption of HPAN. There was some evidence of competition for adsorption sites.

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