Banca de DEFESA: MATEUS TORQUATO SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MATEUS TORQUATO SILVA
DATE: 25/02/2026
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/sala/guilherme-martins-gelfuso
TITLE:

Liposomes coated with chitosan coencapsulating gemcitabine and olaparib as an alternative for the treatment of pancreatic cancer.

KEY WORDS:

Liposomes; Gemcitabine; Olaparib; Nanoparticles; Pancreatic Cancer

PAGES: 100
BIG AREA: Ciências da Saúde
AREA: Farmácia
SUMMARY:

“Pancreatic adenocarcinoma is one of the most lethal neoplasms, and the combination of gemcitabine (GEM) with olaparib (OLA) coencapsulated in nanosystems shows promise as an excellent treatment alternative for this disease, particularly in patients with BRCA gene mutations. This work presents the validation of a simple, fast, and sensitive chromatographic method for the simultaneous analysis of GEM and OLA. Efficient chromatographic separation of GEM and OLA was achieved using a C18 column (250 × 4.6 mm, 5 μm) with a mobile phase composed of acetonitrile and water (50:50, v/v), eluted isocratically at a flow rate of 0.8 mL/min. Determinations were performed using a DAD detector at 243 nm for both drugs. Retention times for GEM and OLA were approximately 3.3 and 4.3 min, respectively. The method showed linearity (r²>0.999), with a regression curve in the concentration range of 0.5 to 10.0 μg/mL, demonstrating sensitivity, precision, and accuracy. Drug recovery rates in pancreatic tissues were greater than 97.0%. The components of the coated liposomal formulation and the pancreatic tissues did not interfere with the analysis, and both drugs showed a low degradation rate under adverse conditions. Furthermore, this work presents the development and characterization of liposomes with and without chitosan oligosaccharide coating. The developed liposomes have an average size (hydrodynamic diameter) of 113 ± 0.46 nm without coating and 114.9 ± 1.84 nm with chitosan oligosaccharide coating, with variations from 110 to 230 nm for both particles. The PdI values are 0.09 ± 0.01 and 0.08 ± 0.02 for uncoated and coated liposomes, respectively. The developed coated liposomes have negative zeta potentials of -7.11 ± 0.43 mV and - 7.66 ± 0.70 mV. The pH of the composition with uncoated and coated liposomes is 7.54 ± 0.02 and 7.58 ± 0.00, respectively, which is close to the physiological pH range. The encapsulation efficiency for liposomes is 49.69 ± 2.16% and 48.56 ± 0.26% for GEM, in coated and uncoated liposomes, respectively, and 79.21 ± 0.22% and 81.51 ± 0.13% for OLA, in coated and uncoated liposomes, respectively. In these liposomal systems, GEM released 73 ± 0.71% and 84 ± 2.90%, and OLA 95 ± 1.56% and 70 ± 1.98%, respectively, in six hours. In HETCAM assays, the coated and uncoated liposomal formulations showed no irritant potential, with irritability indices of 0.0 ± 0.0 and 0.0 ± 0.0 for both formulations and 19.0 ± 0.2 and 0.0 ± 0.0 for the negative and positive controls, respectively. Coated and uncoated liposomes did not show significant changes in hydrodynamic size, PdI, zeta potential, and pH values after 90 days of observation (p > 0.05). In vitro assays showed decreased viability of cells derived from pancreatic cancer, Panc-1, MIA PaCa-2, and BxPC3. In an in vivo model using the chorioallantoic membrane (CAM) of chicken egg embryos, treatment with liposomes promoted a 50% reduction in the area of tumors developed from Panc-1 and BxPC3 xenografts. In conclusion, coated liposomes containing GEM and OLA present themselves as a promising and innovative alternative for the treatment of pancreatic cancer.”

COMMITTEE MEMBERS:
Externo ao Programa - 1912768 - FELIPE SALDANHA DE ARAUJO - nullPresidente - 1880131 - GUILHERME MARTINS GELFUSO
Interno - 1634362 - MARCILIO SERGIO SOARES DA CUNHA FILHO
Externa à Instituição - STEPHÂNIA FLEURY TAVEIRA - UFG