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Program-controlled freeze drying for the preparation of the delivery system of native hyaluronan and hydrophobic molecules
Waczulíková, Kristína ; Sedláček, Petr (referee) ; Enev, Vojtěch (advisor)
The amphiphilic nature of the hyaluronan biopolymer facilitates interactions between its hydrophobic portions of the chain and the hydrophobic ligands, making it one of the promising compounds that can be used as a suitable carrier for drug delivery. Therefore, the aim of this diploma work was by means of a program-controlled freeze-drying to prepare a system based on native hyaluronan, which would be capable of transporting hydrophobic drugs. Perylene, pyrene, prodan and 1,6-diphenyl-1,3,5-hexatriene fluorescence probes were used as model compounds to simulate hydrophobic drug-hyaluronan interactions. Freeze-drying efficiency was studied using infrared spectrometry and scanning electron microscopy. ATR-FTIR spectrometry confirmed for all probes but pyrene the hydrophobic interactions between the hyaluronan and probe molecules based on the presence of the C=C bond valence vibration absorption band in the aromatic probe rings. From the IR spectra, it was not possible to confirm with certainty the presence of residual tert-butyl alcohol in the samples. SEM photographs revealed that increasing the pressure during drying process had a positive effect on the quality of the lyophilized sample in the second series of samples. Interactions of individual fluorescent probes with hyaluronan were studied using steady-state and time-resolved fluorescence spectrometry. Positive results have been obtained, indicating the presence of fluorescent probes interacting with the hydrophobic regions of the hyaluronan chains. The results of this work can contribute to the development of carrier systems in the field of targeted drug distribution.
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Program-controlled freeze drying for the preparation of the delivery system of native hyaluronan and hydrophobic molecules
Waczulíková, Kristína ; Sedláček, Petr (referee) ; Enev, Vojtěch (advisor)
The amphiphilic nature of the hyaluronan biopolymer facilitates interactions between its hydrophobic portions of the chain and the hydrophobic ligands, making it one of the promising compounds that can be used as a suitable carrier for drug delivery. Therefore, the aim of this diploma work was by means of a program-controlled freeze-drying to prepare a system based on native hyaluronan, which would be capable of transporting hydrophobic drugs. Perylene, pyrene, prodan and 1,6-diphenyl-1,3,5-hexatriene fluorescence probes were used as model compounds to simulate hydrophobic drug-hyaluronan interactions. Freeze-drying efficiency was studied using infrared spectrometry and scanning electron microscopy. ATR-FTIR spectrometry confirmed for all probes but pyrene the hydrophobic interactions between the hyaluronan and probe molecules based on the presence of the C=C bond valence vibration absorption band in the aromatic probe rings. From the IR spectra, it was not possible to confirm with certainty the presence of residual tert-butyl alcohol in the samples. SEM photographs revealed that increasing the pressure during drying process had a positive effect on the quality of the lyophilized sample in the second series of samples. Interactions of individual fluorescent probes with hyaluronan were studied using steady-state and time-resolved fluorescence spectrometry. Positive results have been obtained, indicating the presence of fluorescent probes interacting with the hydrophobic regions of the hyaluronan chains. The results of this work can contribute to the development of carrier systems in the field of targeted drug distribution.
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