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Tailoring transport properties of controlled release systems based on polyhydroxyalkanoates.
Apsalikova, Zarina ; Obruča, Stanislav (oponent) ; Sedláček, Petr (vedoucí práce)
In this work, in order to investigate the transport properties of different types of carriers, the polyhydroxyalkanoates with 3-hydroxyvalerate, 4-hydroxyvalerate, 4-hydroxyhexanoate, and 5-hydroxyvalerate monomer units were synthesized using the bacterial strain Aneurinibacillus (isolates: AH30 and AFN2). Results of gas chromatography (GC-FID) showed that isolates are able to accumulate PHA with different fractions of monomers. Further, the molecular weight and polydispersity index of isolated biofilms isolated were analyzed via size exclusion chromatography (SEC-MALS). Then, the delivery systems were fabricated, using synthesized copolymers and commercial homopolymer poly(3-hydroxybutyrate). In particular, a series of optimization experiments focused on particles, films, and porous monolith preparation. The processing conditions were evaluated including polymer concentration, amount of additive, and isolation procedure. Fabricated carriers were characterized regarding their ability to incorporate and release the active agent (ibuprofen) into the model medium (phosphate saline buffer). Based on the results from characterization methods, it was found that polymer structure and polymer-solvent relationship have a significant influence on the transport behavior of the incorporated agent. Techniques, such as Scanning electron microscopy (SEM), Differential scanning calorimetry (DSC), Attenuated total reflectance Fourier-transform infrared (ATR-FTIR) spectrometry and ultraviolet-visible spectroscopy (UV-VIS) were applied as tools to compare and understand the correspondence between transport properties and chemical structure of polyhydroxyalkanoate.
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