DIKUL - logo
(UL)
  • Vpliv formulacijskih in procesnih parametrov na koloidno stabilnost liofiliziranih lipidnih nanodelcev = Impact of process and formulation parameters on the colloidal stability of lyophilised lipid nanoparticles
    Gošek, Teja
    During COVID-19 pandemic, mRNA-LNP vaccines proved to be efficient in preventing COVID-19 infection. The aim of the master thesis was to develop a lyophilizable formulation of lipid nanoparticles ... (LNPs) with the main focus on colloidal stability of LNPs. Self-prepared LNPs with salmon DNA and LNPs from Moderna vaccine were used in the experiments. Particle size and size distribution were evaluated via DLS measurements. For some samples, also encapsulation efficiency of mRNA via RiboGreen assay was evaluated. Several experiments were performed to study effects of different parameters on the colloidal stability of LNPs during freeze-thawing. Following parameters were evaluated: cooling rate, filling volume, pH of the buffer, ionic strength and use of different potential cryoprotectants. Different excipients were analyzed to find appropriate lyoprotectants. Damage caused by freezing step compared to damage caused by the rest of lyophilization process was evaluated by comparing the differences in size and PDI of LNPs in different formulations after freeze-thawing and after whole lyophilization process. Comparing the change in size of LNPs and PDI after freeze-thawing, no visible change was detected if faster or slower cooling rate was used. When analyzing the effect of filling volume, smaller change in size of LNPs was obtained for samples with bigger filling volume. However, PDI was wider for these samples which could potentially mask the difference in size of LNPs after freezing. Regarding pH of formulation, sodium phosphate buffer and potassium phosphate buffer caused substantial LNPs instability. In contrast, only small differences in size of LNPs were detected in Tris buffer. Influence of the ionic strength was analysed using formulations with different concentrations of NaCl. A major size increase of LNPs was detected in a sample with 300 mM NaCl. Some aggregation occurred also in a sample with 150 mM NaCl. Samples with lower NaCl level did not result in pronounced changes in LNPs size. From the various cryoprotectants tested, promising results were obtained for formulations with combination of sucrose with either poloxamer 188 (P188) or hydroxypropyl-β-cyclodextrin (HP-β-CD) and for a sample with 20% sucrose. As potential lyoprotectants, combination of sucrose with both poloxamer 407 (P407) and P188 as well as combination of sucrose with polysorbate 20 (PS20) were determined. Highest encapsulation efficiency of mRNA was obtained in sample with PVP 40 kDa, followed by samples with combination of sucrose with P188 and P407.
    Vrsta gradiva - magistrsko delo ; neleposlovje za odrasle
    Založništvo in izdelava - Ljubljana : [T. Gošek], 2023
    Jezik - angleški
    COBISS.SI-ID - 166695427

Knjižnica Signatura – lokacija, inventarna št. ... Status izvoda
Fakulteta za farmacijo, Ljubljana Knjižnica
mind 66.02 GOŠEK TEJA Vpliv 293
IN: 0017838 		prosto - za čitalnico
loading ...
loading ...
loading ...

Vnos na polico