Abstract In recent years, there has been a resurgence of interest concerning solid-state cultivation processes due to a number of advantages over submerged cultivation. However, studies on oxygen transfer and the performance of bioreactors are lacking. Processes that use inert supports loaded with chemically-defined liquid media have several potential applications and offer numerous advantages, such as improved process control and monitoring and enhanced process consistency compared with cultivation on natural solid substrates. The aim of this research was to study the oxygen transfer for the production of allergenic proteins from a biomass of Drechslera (Helminthosporium) monoceras cultured in a packed-bed reactor filled with polyurethane foam. The results show that a high protein concentration can be produced on an inert support with a high overall oxygen transfer coefficient (KLa) during cultivation.

Cationic liposomes are an alternative to DNA non-viral carrier in gene therapy, promoting higher efficiency for transport and delivery into the cells. Liposome production large scale is still a challenge. Among many processes, from dried film adsorbed inside multitubular system promising due its operational simplicity. this field, engineering contributions scarce no mathematical treatment literature describing type of process available. formulation proposed describe kinetic considering wetting disintegration lipid followed by lipids aggregation bilayers generating liposomes. model has fitted experimental data mass thickness, being useful predictions scaling up as well contributing development pharmaceutical products.

Chitosan microspheres of a small particle size and with good sphericity were prepared by a spray-drying method followed by treatment with a cross-linking agent. Owing to restrictions on the use of cross-linked chitosan microspheres in the pharmaceutical field, d,l-glyceraldehyde, a biocompatible reatant was used. The parameters studied affecting extent of cross-linking were cross-linking time and concentration of the cross-linking agent. Glutaraldehyde, the aldehyde most frequently employed as chemical cross-linking agent for proteins, was also used as a control. The cross-linked spray-dried chitosan microspheres were analyzed with respect to their morphological aspects, particle size, zeta potential and water uptake capacity. It was found that an increase either in d,l-glyceraldehyde concentration or in duration of cross-linking caused a decrease in both the swelling capacity and the zeta potential of the chitosan microspheres. Compared to glutaraldehyde, d,l-glyceraldehyde appears to be a good cross-linking agent for chitosan microspheres with the advantage that it is nontoxic.

This work presents results of the preparation and characterization of small unilamellar liposomes for entrapping allergenic proteins extracted from the biomass of Dreschlera (Helminthosporium) monoceras cultivated by solid fermentation. Protein was entrapped by the dehydration-rehydration method, using lyophilization of preformed liposomes in order to prevent their degradation The reconstitution of lyophilized liposomes by hydration, their capacity for entrapping allergenic proteins and their stability in plasma were analyzed. Liposomes were reconstituted in size by including trehalose sugar in the formulation. The protection of the liposomal membrane by trehalose was characterized by differential scanning calorimetry and X-ray diffraction. The reconstituted membrane had an osmotic behavior similar to that of nondehydrated ones. Allergenic proteins ranging in molecular weight from 14 to 170 kDa were entrapped in the lipid matrix with an efficiency of approximately 80%. These results are promising for producing liposomes by entrapping allergenic proteins from mold extracts, which can be useful for allergy therapy.

Unloaded microspheres were prepared from polyhydroxybutyrate (PHB) and polyhydroxybutyrate-co-valerate (PHB-HV) polymers using an oil-in-water emulsion solvent evaporation method. The study was conducted to evaluate how the polymer and some process parameters affect properties of the final microspheres such as particle size, superficial area, zeta potential, surface morphology and microsphere degradation. The variables included surfactant concentration in the emulsion water phase and solvent composition. From the results, it was found that the parameters affecting microsphere size the most were surfactant concentration in the emulsion water phase and solvent composition. Properties such as zeta potential, surface area and surface morphology remained pratically unchanged over the range of the processing conditions studied here.