iridoids and triphosphoric-acid

The objective of this work was to investigate material properties and osteogenic differentiation of human mesenchymal stem cells (hMSCs) in genipin (GN) crosslinked chitosan/nano β-tricalcium phosphate (CS/nano β-TCP) scaffolds, and compare the results with tripolyphosphate (TPP) crosslinked scaffolds. Porous crosslinked CS/nano β-TCP scaffolds were produced by freeze-gelation using GN (CBG scaffold) and TPP (CBT scaffold) as crosslinkers. The prepared CBT and CBG scaffolds were characterized with respect to porosity, pore size, water content, wettability, compressive strength, mass loss, and osteogenic differentiation of hMSCs. All scaffolds displayed interconnected honeycomb-like microstructures. There was a significant difference between the average pore size, porosity, contact angle, and percent swelling of CBT and CBG scaffolds. The average pore size of CBG scaffolds was higher than CBT, the porosity of CBG was lower than CBT, the water contact angle of CBG was higher than CBT, and the percent swelling of CBG was lower than CBT. At a given crosslinker concentration, there was not a significant difference in compressive modulus and mass loss of CBG and CBT scaffolds. Metabolic activity of hMSCs seeded in CBG scaffolds was slightly higher than CBT. Furthermore, CBG scaffolds displayed slightly higher extent of mineralization after 21 days of incubation in osteogenic medium compared to CBT.

Topics: Alkaline Phosphatase; Biocompatible Materials; Calcium Phosphates; Cell Differentiation; Cell Survival; Cells, Cultured; Chitosan; Compressive Strength; Gels; Humans; Iridoids; Materials Testing; Mesenchymal Stem Cells; Nanostructures; Osteogenesis; Polyphosphates; Porosity; Spectroscopy, Fourier Transform Infrared; Tissue Scaffolds; X-Ray Diffraction

Selective isolation of Kunitz trypsin inhibitor (KTI) and lectin from soybean whey solutions by different types of chitosan beads was investigated. The chitosan beads were co-crosslinked with tripolyphosphate/genipin in solutions at pH 5, 7 or 9 (CB5, CB7, CB9). The maximum adsorption ratios of chitosan beads to KTI and lectin were observed at pH 4.4 and 5.4, respectively; highly selective separation was also demonstrated at these pHs. The adsorption ratios increased with temperature, rising between 5 and 25 °C. CB9 produced the best adsorption ratio, followed by CB7 then CB5. The critical interaction governing absorption of chitosan beads to KTI and lectin could be hydrogen bonding. At pH 9, KTI and lectin desorbed efficiently from CB7 with desorption ratios of 80.9% and 81.4%, respectively. The desorption was most likely caused predominantly by electrostatic repulsion. KTI and lectin can effectively be selectively isolated from soybean whey using this novel separation technique.

Topics: Adsorption; Chitosan; Cross-Linking Reagents; Glycine max; Hydrogen-Ion Concentration; Iridoids; Plant Lectins; Plant Proteins; Polyphosphates; Solutions; Trypsin Inhibitors

Solid wastes generated from the seafood industry represent an important environmental pollutant; therefore, utilization of those wastes for the development of processing biochemical tools could be an attractive and clean solution for the seafood industry. This study reports the immobilization of semi-purified acidic proteases from Monterey sardine stomachs onto chitin and chitosan materials extracted from shrimp head waste. Several supports (chitosan beads, chitosan flakes, and partially deacetylated flakes) were activated either with genipin or Na-tripolyphosphate and evaluated as a mean to immobilize acidic proteases. The protein load varied within the 67-91% range on different supports. The immobilization systems based on chitosan beads achieved the highest protein loads but showed the lowest retained catalytic activities. The best catalytic behavior was obtained using partially deacetylated chitin flakes activated either with genipin or Na-tripolyphosphate. According to results, the immobilization matrix structure, as well as acetylation degree of chitin-chitosan used, has considerable influence on the catalytic behavior of immobilized proteases. Partially deacetylated chitin flakes represent a suitable option as support for enzyme immobilization because its preparation requires fewer steps than other supports. Two abundant seafood by-products were used to obtain a catalytic system with enough proteolytic activity to be considered for biotechnological applications in diverse fields.

Topics: Animals; Biotechnology; Chitin; Chitosan; Enzymes, Immobilized; Fishes; Industrial Waste; Iridoids; Penaeidae; Peptide Hydrolases; Polyphosphates