Nanostructured multifunctional systems for drug release through the nasal route applied on glioblastoma treatment

Author(s)

Natália Noronha Ferreira Naddeo

• Document type: Doctoral Thesis
• Press: Araraquara. 2020-05-23.
• Institution: Universidade Estadual Paulista (Unesp). Faculdade de Ciências Farmacêuticas. Araraquara
• Defense date: 2020-03-30
• Advisor: Maria Palmira Daflon Gremião; Fátima Baltazar

Abstract

Glioblastomas (GBM) account for 77% of malignant tumors in the central nervous system (SNC), and today, despite all advances in therapy, remains with a limited prognosis. The existence of physiological barriers as the blood brain barrier (BBB) represents the main obstacle that limits appropriate concentrations of drugs designed to therapy. Due to their anatomical advantages, a strategy proposed for direct delivery to SNC involves the use of the nose-to-brain route. Besides, combination therapy that uses multiple drugs against different molecular targets should be considered for complex diseases such as GBM. Drugs like alpha-cyano-4-hydroxycinnamic acid (CHC) and the monoclonal antibody cetuximab (CTX) are already explored for their capacity to act against different hallmarks of cancer and applied together, as a novel combining approach, might improve therapeutic outcomes. Therefore, advances in nanotechnology-based delivery systems will inevitably bring therapeutic gains to the proposed combination since they enable acquisition of important characteristics desired and also the association of different drugs into a single carrier. Thus, the current study proposes the development of different polymeric platforms based on poly(lactic-co-glycolic acid) (PLGA) and trimethyl chitosan (TMC) /chitosan oligosaccharide (OCS) for CHC encapsulation. Both CHC-loaded developed systems (PLGA/TMC and PLGA/OCS) exhibited nanostructure organization of about 300 to 400 nm, containing chitosan on their outermost surface (positive zeta potential) and a high percentage of CHC encapsulation (±85%). Physicochemical characteristics have shown great colloidal stability, especially in the presence of CHC drug. DRX data suggest that interaction between CHC and PLGA/OCS NPs follows patterns different than PLGA/TMC NPs. Conjugation between CTX and developed CHCloaded NPs was optimally obtained by supramolecular forces and covalent bonds, resulting in 85 and 58% of efficacy, respectively. Analysis of therapeutic efficacy using in vitro protocols employing U251 and SW1088 glioma cell lines, established that, comparing both conjugated systems, PLGA/OCS seems to have greatly therapeutic capacity. Therefore, this system was chosen to further investigations. Blot analysis confirmed that CTX associated with NPs continues to exert its therapeutic efficacy. Analysis of antiangiogenic activity, tumor development, and progression using the chicken chorioallantoic membrane disclosed a trend of tumor reduction when conjugated NPs were employed. In addition, this system also exhibited antiangiogenic activity. In vitro release profile showed that CHC release was sustained and retarded by drug encapsulation into NPs. The ex vivo permeation study applying nasal porcine mucosal showed that CHC permeation was delayed by the inclusion of system complexity. Analysis of NPs delivery using fluorescence tomography provides evidence that the developed PLGA/OCS NPs, independently of conjugation procedure,were effective in providing nose-to-brain transport. Taking into consideration all of the aforementioned results, we anticipate that the developed system exhibited a set of favorable attributes that make them promising alternatives to be further considered in GBM treatment. (AU)