Development and evaluation of bioadhesive cationic nanocarriers as a platform for localizing piplartine in the breast tissue aiming tumor treatment.

Author(s)

Vanessa Franco Carvalho Dartora

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Ciências Biomédicas (ICB/SDI)
• Defense date: 2021-01-13

Examining board members

Luciana Biagini Lopes; Sílvia Stanisçuaski Guterres; João Agostinho Machado Neto; Paulo Roberto Regazi Minarini

• Advisor: Luciana Biagini Lopes; Leticia Veras Costa Lotufo

Abstract

Breast cancer is a major cause of death among women, accounting for about 25% of new annual cases. In situ ductal carcinomas (DCIS) represent the most common form of noninvasive breast cancer. Considering that DCIS usually begins in the epithelial cells that line the ducts, in this study, we developed bioadhesive nanoemulsions (NE) and thermosensitive pNIPAM polymeric nanoparticles (NP) for intraductal administration of the chemotherapeutic agent piplartine (piperlongumine). To confer bioadhesive properties, the NE was modified with chitosan (NE-Q) or hyaluronic acid (NE-HA). The use of phosphatidylcholine associated with polysorbate 80 and glycerol as surfactants enabled the formation of systems with 76.5 ± 1.2 nm. The inclusion of chitosan or hyaluronic acid resulted in NEs with opposite charge, similar in vitro bioadhesive potential and comparable capacity to prolong in vivo breast tissue retention of a fluorescent marker for up 120 h compared to the solution and systemic administration of the compound. No histological changes and local irritation were observed. The PNIPAM nanoparticles were modified with the SILY peptide for collagen binding and targeting, and piplartine was coencapsulated with a MK2 inhibitor peptide (YARA) to potentiate cytotoxicity. The average diameter of NPs was 361.5 ± 04.6 nm, with a decrease in the hydrodynamic radius at temperatures above the lower critical solution temperature. NP in vivo intraductal administration prolonged the retention of rhodamine in the breast tissue for up 120 h without promoting histological changes. The IC50 of piplartine in solution was 10.1 - 11.3 <font face = \"symbol\">mM in T47-D and MCF-7 breast cancer cell lines. Its incorporation in NE-HA and NP resulted in an increase in the cytotoxic effect and a reduction of IC50 up to 3.6 times for NE-HA and 1.6 times for NP. An additional reduction (~ 4.0 times) was observed with the combination of piplartine and YARA in NP. Even more pronounced results were observed in 3D models, represented by T47-D or MCF7 spheroids, with an IC50 reduction of 6.6- and 4.6-times using NE-HA and NP, respectively. Consistent with the results in monolayer cell culture, the combination of piplartine and YARA in NP further reduced the piplartine IC50 (~ 15 times) in spheroids. The nanocarriermediated increase in cytotoxicity may result from a more efficient cell penetration, as observed by visualizing the penetration of rhodamine B in 2D and 3D cultures. In a preclinical model of breast cancer, 77,7% of the animals in the induced untreated group developed palpable tumors (2.5 ± 1.6 tumors per animal). On the other hand, similar to the non-induced group, palpable tumors were not observed in the group treated with NE-HA, while treatment with NP reduced the incidence of these tumors by 18 times. These results were confirmed through histological analyzes, in which histological changes compatible with DCIS were observed in the induced and untreated group, while the groups treated with NE-HA and NP showed a pattern of tissue organization similar to the uninduced control group. Together, these results demonstrate the advantages of piplartine nanoencapsulation and its combination with the MK2 inhibitor, and the potential applicability of the nanocarriers developed for intraductal administration and treatment of DCIS and low-risk mammary lesions. (AU)

• FAPESP's process: 17/04174-4 - Development and evaluation of cationic bioadhesive nanocarriers as a platform to localize piplartine in the breast for tumor treatment
• Grantee: Vanessa Franco Carvalho Dartora
• Support Opportunities: Scholarships in Brazil - Doctorate