National Repository of Grey Literature 3 records found  Search took 0.02 seconds. 
Study of stability of antimicrobial nanomaterials in different environment by HPLC
Janderová, Šárka ; Trachtová, Štěpánka (referee) ; Márová, Ivana (advisor)
This thesis deals with the preparation of nanomaterials (nanoparticles, nanofibers) with encapsulated active substances and the stability of these nanomaterials in different environments using liquid chromatography. The development and optimization of methods for monitoring the kinetics of release of encapsulated substances from nanomaterials into various environments play a key role in research aimed at their utilization in the pharmaceutical, food, and cosmetic industries, and also contribute to the development of new antimicrobial nanomaterials limiting antibiotic resistance. The theoretical part focuses on the characterization of nanomaterials (nanoparticles, liposomes, nanofibers, and combined nanomaterials). Another section of the literature review deals with natural (eugenol, carvacrol, curcumin, thymol, vitamin E) and synthetic (ampicillin, streptomycin) antimicrobial substances. The final chapter discusses the instrumental methods used for the characterization of nanomaterials and the evaluation of their stability, released, and degradation products. In the practical part, the antioxidant activity of selected substances was first monitored. Liposomes were prepared, and their stability and encapsulation efficiency were examined. An HPLC method for determining active substances was optimized. Subsequently, the gradual release of the mentioned active substances from prepared liposomes was monitored. Nanofibers were prepared using forcespinning, and their release into selected model environments was also analyzed. Distilled water with minimal ion and impurity content served as a model environment, as well as a physiological solution at 25°C, simulating the temperature of the human body surface, and a physiological solution at 37°C, characteristic of human body temperature. This analysis provides a comprehensive view of the behavior of prepared materials and their potential practical applications. In the final section, combined nanomaterials (based on nanofibers and nanoparticles) with encapsulated active substances were prepared. The gradual release of active substances and any potential synergistic effects were examined for these nanomaterials.
Preparation of microbial, plant and algal extracts to use in cosmetics for infants
Janderová, Šárka ; Dzurická, Lucia (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the preparation of a cosmetic product for infants with the addition of active substances from cyanobacteria, microalgae, or plants. In the theoretical part, a review was made, which not only summarizes the basic information about these organisms, but also the antioxidants contained in these microorganisms. In the practical part, several types of extracts from cyanobacteria, algae and plants were prepared and characterized. The content of phenolic substances, chlorophylls and content of carotenoids were measured spectrophotometrically. Content of soluble proteins was determined by Hartree-Lowry method and the fatty acid profile in biomass was obtained by GC. Furthermore, the SPF factor was measured using the spectrophotometric method the Mansur equation. Antioxidant activity was determined by using the TEAC method. Finally, two of the best extracts were selected for the preparation of cosmetic emulsions. The sensory analysis of prepared emulsions was performed for the period of two weeks.
Preparation of microbial, plant and algal extracts to use in cosmetics for infants
Janderová, Šárka ; Dzurická, Lucia (referee) ; Márová, Ivana (advisor)
This bachelor thesis deals with the preparation of a cosmetic product for infants with the addition of active substances from cyanobacteria, microalgae, or plants. In the theoretical part, a review was made, which not only summarizes the basic information about these organisms, but also the antioxidants contained in these microorganisms. In the practical part, several types of extracts from cyanobacteria, algae and plants were prepared and characterized. The content of phenolic substances, chlorophylls and content of carotenoids were measured spectrophotometrically. Content of soluble proteins was determined by Hartree-Lowry method and the fatty acid profile in biomass was obtained by GC. Furthermore, the SPF factor was measured using the spectrophotometric method the Mansur equation. Antioxidant activity was determined by using the TEAC method. Finally, two of the best extracts were selected for the preparation of cosmetic emulsions. The sensory analysis of prepared emulsions was performed for the period of two weeks.

Interested in being notified about new results for this query?
Subscribe to the RSS feed.