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Stable composite callus culture pectin/alginate hydrogel matrices were prepared using the ionotropic gelation method. The presence of 0.5% alginate in composites based on pectin from campion callus (SVC) led to an increase in gel strength. The particles based on pectin from tansy callus (TVC) had a higher Ca2+ content and gel strength due to the lower degree of methylesterification (DM) compared with SVC and apple pectins. The entrapment of 0.5% alginate to gel formulations based on the pectins led to an increase in the swelling properties independently of the concentration and the chemical composition of the pectin. Composite particles with a higher pectin concentration and Ca2+ content had an increased swelling degree in the simulated digestive fluids. The swelling degree of the particles based on alginate and/or TVC was higher than that of the particles based on SVC. At incubation in SCF-2.3 (pH 2.3 + pectinase) and SCF-4.0 (pH 4.0 + pectinase) fluids simulating colon inflammation, the swelling degree of particles in SCF-2.3 was lower than in SCF-4.0, as well as in SCF-7.0 (pH 7.0 + pectinase), which mimics a healthy large intestine. After incubation in the simulated digestive fluids, the particle gel strength decreased. All particles showed the lowest gel strength and increased degradation in SCF-4.0. The composite systems based on callus culture pectins showed a high stability at pH 1.25, 2.3, 4.0 and 7.0 and were degraded partially by pectinase. These composite hydrogel matrices can be used in colon-specific drug delivery systems for colon inflammation. [ABSTRACT FROM AUTHOR]

The aim of this research was to produce composite gel microparticles based on the pectin (campion callus culture (SVC) and commercial apple (AU) pectins) and κ-carrageenan and investigate the relationship between the characteristics and swelling properties of the composite microparticles. The microparticles were obtained using emulsion dehydration techniques with successive incubation in calcium chloride solution. A significant positive correlation between the Ca2+ content and the SVC concentration in gel formulations was shown. Decreasing degree of methyl esterification (DM) of the SVC pectin promoted Ca2+ binding in comparison with the AU pectin. Increasing concentration of the pectin promoted increasing gel strength of the composite microparticles. The higher gel strength of the composite microparticles based on the SVC pectin was probably due to the lower DM and a higher linearity in comparison with the AU pectin. The microparticle gel formulations with a higher pectin concentration had a lower swelling degree in the simulated digestive fluids. The addition of the carrageenan to the gel formulations led to an increase in the swelling degree in comparison with that without carrageenan. The correlation analysis indicated that increasing initial Ca2+ content and gel strength of the microparticles promoted decreasing swelling degree of the composite microparticles. • Composite gel microparticles based on the pectin and κ-carrageenan were obtained. • The microparticles from the pectin with the lowest DM had the highest Ca2+ content. • A higher pectin concentration in the microparticles promoted a lower swelling degree in the digestive fluids. • The addition of the carrageenan to the gel formulations led to an increase in the swelling degree. • Increasing Ca2+ content and gel strength of the microparticles promoted decreasing the swelling degree. [ABSTRACT FROM AUTHOR]

Composite gel microparticles based on alginate and callus culture pectins with low and high degrees of methylesterification or apple pectin were produced. By varying the chemical composition of the pectic samples and the ratio of alginate to pectin, the gel strength, morphology, and swelling properties of composite microparticles can be altered. The inclusion of increasing concentrations of alginate in gel formulations promoted an increase in the microparticle gel strength and the formation of a smoother surface microrelief independently of the pectin chemical composition. Microparticles based on the pectin with a low degree of methylesterification (DM) and a higher concentration of alginate exhibited an increased swelling degree in the simulated digestive fluids. Microparticles based on the pectin with high DM and low alginate concentration were destroyed in the simulated intestinal fluid within 1 h due to the low Ca2+ content, gel strength, and grooved and rough surface of these microparticles. An increase in alginate concentration of gel formulations based on pectin with high DM led to increased stability of the microparticles in the simulated intestinal and colonic fluids due to increased Ca2+ content, microparticle gel strength and degree of crosslinking. • The ratio of alginate to pectin influences the gel strength and morphology of microparticles. • The ratio of alginate to pectin changes the swelling properties of microparticles. • Increasing concentration of alginate promoted increasing the microparticle gel strength. • Alginate increase stability of the microparticles based on the pectin with low DM • The higher stability of microparticles was due to the higher degree of crosslinking. [ABSTRACT FROM AUTHOR]

Composite hydrogel microparticles based on pectins with different structures (callus culture pectin (SVC) and apple pectin (AU)) and gelatin were developed. Hydrogel microparticles were formed by the ionotropic gelation and electrostatic interaction of COO− groups of pectin and NH 3 + groups of gelatin, which was confirmed by FTIR spectroscopy. The addition of gelatin to pectin-based gel formulations resulted in a decrease in gel strength, whereas increasing gelatin concentration enhanced this effect. The microparticle gel strength increased in proportion to the increase in the pectin concentration. The DSC and TGA analyzes showed that pectin-gelatin gels had the higher thermal stability than individual pectins. The gel strength, Ca2+ content and thermal stability of the microparticles based on gelatin and SVC pectin with a lower degree of methylesterification (DM) (14.8 %) were higher compared to that of microparticles based on gelatin and AU pectin with a higher DM (40 %). An increase in the SVC concentration, Ca2+ content and gel strength of SVC-gelatin microparticles led to a decrease in the swelling degree in simulated gastrointestinal fluids. The addition of 0.5 % gelatin to gels based on AU pectin resulted in increased stability of the microparticles in gastrointestinal fluids, while the microparticles from AU without gelatin were destroyed. • Hydrogel microparticles based on pectins with different structures and gelatin were developed. • Pectin-gelatin microparticles were formed by ionotropic gelation and electrostatic interaction. • The electrostatic interaction between pectin and gelatin molecules was confirmed by FTIR. • Pectin-gelatin hydrogels had the higher thermal stability than individual pectins. • The gel strength and swelling behaviour of particles were modified by changing the pectin structure. [ABSTRACT FROM AUTHOR]

The aim of this research is to investigate the influence of the surface morphology of the calcium pectinate gel (CaPG) beads as well as the physicochemical characteristics of pectins and the CaPG beads on the adhesive properties of gels against the Gram-negative bacteria Escherichia coli and the Gram-positive bacteria Bacillus subtilis . The adhesion of the bacteria depends on the type of pectin and the surface morphology of the beads. The faster adhesion on CaPG beads appeared to be related to a lower degree of methyl esterification (DE), a higher molecular weight (Mw) and specific viscosity of the pectin and a higher gel strength. Surface roughness measurements were performed using an atomic force microscope. The beads from pectins with a higher Mw, a higher specific viscosity and a lower DE had a higher surface roughness. The surface roughness was one of the factors promoting adhesion of the bacteria onto the calcium pectinate gels. The surface morphology was observed under a scanning electron microscope (SEM). SEM images illustrated that E. coli and B. subtilis adhered on the beads with a rough surface. CaPG beads obtained from callus culture pectins can be proposed for the preparation of gels with adhesive and antiadhesive properties. [ABSTRACT FROM AUTHOR]

The aim of this work was to evaluate the relationship between the cross-linking cation content in the microparticles, chemical characteristics of pectins and swelling properties of the gel microparticles based on the Zn2+, Fe3+ and Al3+ cross-linking cations. A significant negative correlation between the Zn2+ content and DM of pectin indicated that decreasing DM of pectin promoted Zn2+ binding. The microparticles from the pectins with a higher linearity had a higher content of Fe3+. The microparticles from the pectins with a lower Mw, branching of rhamnogalacturonan I, amount of RG, specific viscosity and a higher linearity had a higher content of Al3+. The content of the Fe3+ ions in the microparticles was higher than the Zn2+ content. The Al3+ content in the microparticles was lowest. The Fe3+ and Zn2+ ions, which are more electronegative, bind more strongly to pectin in comparison with the less electronegative Al3+ cations. The microparticles with a higher Zn2+, Fe3+, and Al3+ content had a lower swelling degree in the simulated digestive fluids. Moreover, the higher swelling of the microparticles can be due to their porous or wrinkled surface. Variation of specific cations and pectins can influence the functionality of the gel microparticles, in particular swelling properties. • The pectic microparticles were prepared using the emulsion dehydration method with modifications. • The microparticles from the pectin with the lowest DM had the highest Zn2+ content. • The microparticles from the pectins with a higher linearity had a higher content of Fe3+ and Al3+. • A higher Zn2+, Fe3+ or Al3+ content in the microparticles promoted a lower swelling degree in the digestive fluids. • The Fe3+ and Zn2+ ions, which are more electronegative, bind more strongly to pectin compared to the Al3+ cations. [ABSTRACT FROM AUTHOR]

Abstract The aim of this work is to produce calcium pectin-silica gel beads containing mesalazine as a drug model in order to control the drug release in the colon. The mesalazine loaded calcium pectin-silica gel beads were prepared using the ionotropic gelation method. Energy-dispersive X-ray analysis revealed that increasing the Na 2 SiO 3 concentration led to an increase of the silicon content on the surface and in the cross-sections of the beads. The addition of Na 2 SiO 3 to the gel formulations made from the duckweed callus culture pectin led to a decrease in the swelling degree that appeared to be related to the higher gel strength of these beads. The beads made from pectins of campion and duckweed callus cultures with adding of 22.2 mg/ml of Na 2 SiO 3 showed the lowest release of mesalazine in simulated gastric and intestinal fluids. An increase in the reaction time up to 60 min during incubation in the cross-linking solution of CaCl 2 led to a slower release of drug from the beads. An elevated release of mesalazine was achieved in the simulated colonic fluid. Prepared calcium pectin-silica gel beads containing mesalazine as a drug model can be proposed for controlled drug release in the colon. Highlights • The mesalazine loaded pectin-silicate gel beads were prepared using the ionotropic gelation method. • The pectin-silicate gel beads made from the duckweed callus culture pectin had the higher gel strength. • The pectin-silicate gel beads with the higher content of silicon showed the lowest release of mesalazine. • An elevated drug release from pectin-silicate gel beads was achieved in the simulated colonic media. [ABSTRACT FROM AUTHOR]