Artur Bartkowiak

Cytotoxicity study of novel water‐soluble chitosan derivatives applied as membrane material of alginate microcapsules

The majority of cell encapsulation systems applied so far are based on polyelectrolyte complexes of alginate and polyvalent metal cations. Although widely used, these systems suffer from the risk of disintegration. This can be partially solved by applying chitosan as additional outer membrane. However, chitosan can be dissolved in water only at a low pH, which limits its use in the field of bioencapsulation. In this study, novel primary and tertiary amine chitosan derivatives have been synthesized, which may be dissolved at pH 7.0, and retain the ability to effectively form additional membrane on the surface of alginate beads. As aqueous solutions tertiary amines dimethylamino-1-propyl-chitosan and dimethylethylamine-chitosan with linear hydrochloride aliphatic chains had the lowest toxicity, whereas dimethylpropylamine-chitosan, diethylaminoethyl-chitosan, and diisopropylaminoethyl-chitosan with branched hydrochloride aliphatic were cytotoxic to the majority of tested cells. When applied as polyelectrolyte complexation agent on the surface of alginate beads, none of the derivates had any negative effect on the metabolic activity of encapsulated beta-cells.

Antibacterial activity of rosemary, caraway and fennel essential oils

Summary Introduction: Recently, interest in essential oils used in natural medicine, has been increasing. Essential oils are still being tested for their potential uses as an alternative remedies for the treatment of many infectious diseases. Objective: The aim of the study was to evaluate antibacterial properties of commercial essential oils (rosemary, caraway and fennel) to reduce the number of Staphylococcus aureus and Escherichia coli. Methods: The antibacterial activity of essential oils was investigated by agar dilution method. Results: The result of experiments showed that essential oils contained in microbiological media significantly reduced the number of S. aureus and E. coli cells. The best antibacterial properties possessed caraway oil: 1 mg/g for S. aureus and 10 mg/g for E. coli, weaker rosemary (5 mg/g) and fennel (20 mg/g) oils. Conclusion: Results confirmed the inhibiting effect of commercial essential oils on S. aureus and E. coli and provide a scientific ground for future research.

The Influence of Accelerated UV-A and Q-SUN Irradiation on the Antimicrobial Properties of Coatings Containing ZnO Nanoparticles

The influence of accelerated UV-A and Q-SUN irradiation on the antimicrobial properties of coatings containing ZnO nanoparticles was investigated using a polyethylene (PE) film covering. The results of the study showed that Methyl Hydroxypropyl Celluloses (MHPC) coatings did not influence the growth of S. aureus, B. cereus, E. coli, P. aeruginosa or C. albicans cells. MHPC coatings containing ZnO nanoparticles inhibited the growth of bacterial strains and reduced the number of C. albicans strains. Accelerated Q-SUN and UV-A irradiation had no influence on the antimicrobial effect of nano ZnO coatings against S. aureus, B. cereus and E. coli. Q-SUN irradiation decreased the activity of MHPC coatings containing nanoparticles against P. aeruginosa and C. albicans. An FT-IR analysis clearly showed that ZnO nanoparticles shielded the MHPC coating during Q-SUN irradiation.

Innovations in Food Packaging Materials

Over the last decade, food packaging technology has gone through a fast and significant development especially in case of innovative materials, where some of them are already commercially applied. This chapter explores the innovations in food packaging materials in combination with factors that will affect its further development and potential industrial application.