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Projeto de investigação
NEWPATH: New Advances on Synergistic Antibacterial Coatings Against Pathogenic Bacteria.
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Development of New Targeted Nanotherapy Combined with Magneto-Fluorescent Nanoparticles against Colorectal Cancer
Publication . Marcelo, Gonçalo A.; Montpeyó, David; Galhano, Joana; Martínez-Máñez, Ramón; Capelo-Martínez, José Luis; Lorenzo, Julia; Lodeiro, Carlos; Oliveira, Elisabete; LAQV@REQUIMTE; DQ - Departamento de Química; MDPI - Multidisciplinary Digital Publishing Institute
The need for non-invasive therapies capable of conserving drug efficiency and stability while having specific targetability against colorectal cancer (CRC), has made nanoparticles preferable vehicles and principal building blocks for the development of complex and multi-action anti-tumoral approaches. For that purpose, we herein report the production of a combinatory anti-tumoral nanotherapy using the production of a new targeting towards CRC lines. To do so, Magneto-fluorescent NANO3 nanoparticles were used as nanocarriers for a combination of the drugs doxorubicin (DOX) and ofloxacin (OFLO). NANO3 nanoparticles’ surface was modified with two different targeting agents, a newly synthesized (anti-CA IX acetazolamide derivative (AZM-SH)) and a commercially available (anti-epidermal growth factor receptor (EGFR), Cetuximab). The cytotoxicity revealed that only DOX-containing nanosystems showed significant and even competitive cytotoxicity when compared to that of free DOX. Interestingly, surface modification with AZM-SH promoted an increased cellular uptake in the HCT116 cell line, surpassing even those functionalized with Cetuximab. The results show that the new target has high potential to be used as a nanotherapy agent for CRC cells, surpassing commercial targets. As a proof-of-concept, an oral administration form of NANO3 systems was successfully combined with Eudragit® enteric coating and studied under extreme conditions.
Tailoring Mesoporous Silica-Coated Silver Nanoparticles and Polyurethane-Doped Films for Enhanced Antimicrobial Applications
Publication . Nuti, Silvia; Fernández-Lodeiro, Adrián; Galhano, Joana; Oliveira, Elisabete; Duarte, Maria Paula; Capelo-Martínez, José Luis; Lodeiro, Carlos; Fernández-Lodeiro, Javier; DQ - Departamento de Química; LAQV@REQUIMTE; MEtRICS - Centro de Engenharia Mecânica e Sustentabilidade de Recursos; MDPI AG
The global increase in multidrug-resistant bacteria poses a challenge to public health and requires the development of new antibacterial materials. In this study, we examined the bactericidal properties of mesoporous silica-coated silver nanoparticles, varying the core sizes (ca. 28 nm and 51 nm). We also investigated gold nanoparticles (ca. 26 nm) coated with mesoporous silica as possible inert metal cores. To investigate the modification of antimicrobial activity after the surface charge change, we used silver nanoparticles with a silver core of 28 nm coated with a mesoporous shell (ca. 16 nm) and functionalized with a terminal amine group. Furthermore, we developed a facile method to create mesoporous silica-coated silver nanoparticles (Ag@mSiO2) doped films using polyurethane (IROGRAN®) as a polymer matrix via solution casting. The antibacterial effects of silver nanoparticles with different core sizes were analyzed against Gram-negative and Gram-positive bacteria relevant to the healthcare and food industry. The results demonstrated that gold nanoparticles were inert, while silver nanoparticles exhibited antibacterial effects against Gram-negative (Escherichia coli and Salmonella enterica subsp. enterica serovar Choleraesuis) and Gram-positive (Bacillus cereus) strains. In particular, the larger Ag@mSiO2 nanoparticles showed a minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of 18 µg/mL in the Salmonella strain. Furthermore, upon terminal amine functionalization, reversing the surface charge to positive values, there was a significant increase in the antibacterial activity of the NPs compared to their negative counterparts. Finally, the antimicrobial properties of the nanoparticle-doped polyurethane films revealed a substantial improvement in antibacterial efficacy. This study provides valuable information on the potential of mesoporous silica-coated silver nanoparticles and their applications in fighting multidrug-resistant bacteria, especially in the healthcare and food industries.
Evaluation of positively charged benzothioxanthene imide derivatives as potential photosensitizers for antimicrobial photodynamic therapy
Publication . Lodeiro, Carlos; Galhano, Joana Filipa Candieira; Puchan Sánchez, Dário; Kassem, Ahmad; Allain, Magali; Duarte, Maria Paula; Cabanetos, Clement; Oliveira , Elisabete; DQ - Departamento de Química; LAQV@REQUIMTE; MEtRICS - Centro de Engenharia Mecânica e Sustentabilidade de Recursos; PROTEOMASS Scientific Society
Given the growing concern over antimicrobial resistance (AMR), the search for new alternative therapeutic strategies has increased, with antimicrobial photodynamic therapy (aPDT) emerging as a promising solution. This study aims at exploring the potential of two positively charged BTI derivatives, namely BTI-Pyr+-CH3 (C1) and DBI-Pyr+-CH3 (C2) as photosensitizers for aPDT. In this context, C1 and C2 were successfully synthesized, fully characterized, and their antibacterial activity against Gram-negative and Gram-positive bacteria evaluated. The results demonstrate that both compounds exhibit phototoxic effects under light exposure, with enhanced inhibitory and bactericidal activity at lower concentrations than those reported in the existing literature. Notably, Compound C1 displayed the most promising antibacterial effects, showing inhibitory activity at concentrations approximately 20 times lower than those previously reported. The study highlights the significant light-dependent antibacterial properties of these affordable and accessible compounds, particularly against Gram-positive bacteria, suggesting a potential use for future antimicrobial applications.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
OE
Número da atribuição
2022.09495.BD