Encapsulation of Gold Nanostars and Flavonoids with Thermosensitive Liposomes for the Photothermal Treatment of Oropharyngeal Carcinoma-Derived Cells

• Grant number: 25/00626-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: March 01, 2025
• End date: February 28, 2027
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Pedro Henrique Benites Aoki
• Grantee: Bruna Alves Martins
• Host Institution: Faculdade de Ciências e Letras (FCL-ASSIS). Universidade Estadual Paulista (UNESP). Campus de Assis. Assis , SP, Brazil
• Associated research grant: 22/02189-2 - Plasmonic nanostructures for synergistic photodynamic (PDT) and photothermal (PTT) therapy of cancer cells, AP.PNGP.PI

Abstract

Oropharyngeal carcinoma is an aggressive type of cancer, responsible for around 48 thousandannual deaths worldwide. Conventional therapies face significant limitations,such as severe side effects and low selectivity, highlighting the need for approachesmore effective and less invasive. Photothermal therapy (TFT) emerges as an alternativepromising, using photothermal agents capable of converting light into heat to destroytumor cells, minimizing damage to healthy tissues. Gold nanostructures, such asnanostars (AuNSs) have stood out in this scenario due to their biocompatibility,stability and high light absorption capacity in the near infrared (NIR), whichovercomes the limited penetration of visible light into biological tissues. However, the induction ofPredominantly necrotic cell death can trigger inflammatory responses insurrounding healthy tissues. To mitigate these effects, it is proposed to encapsulate theAuNSs in thermosensitive liposomes associated with flavonoids, forming the nanoplatformAuNSs-Flav@Lip. This strategy allows the controlled release of compounds withanti-inflammatory properties during treatment. This project aims to synthesize AuNSs anddevelop the AuNSs-Flav@Lip system, evaluating its photothermal efficiency in cellsoropharyngeal carcinoma (HEp-2) through cytotoxicity assays (MTT) and release ofLDH, analysis of cell death mechanisms via flow cytometry, and images obtained byconfocal microscopy. The structural characterization of the nanostructures will be carried out usingtechniques such as UV-Vis, DLS, zeta potential and TEM. Photoactivation of the AuNSsFlav@Lip system has the potential to optimize treatments for aggressive tumors, promoting highselectivity, lower inflammation and preservation of healthy tissues.