Avaliação do potencial do ácido gálico encapsulado em Metal-Organic Frameworks funcionalizados com cetuximabe no tratamento do câncer de próstata
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Data
2021-12-08
Autores
Hanck-Silva, Gilmar
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Universidade Estadual Paulista (Unesp)
Resumo
O câncer de próstata é uma das mais comuns neoplasias e uma das principais causas de morte relacionadas ao câncer em homens no Brasil e no mundo, constituindo um sério problema de saúde pública, sendo que a agressividade desta neoplasia está relacionada principalmente com a superexpressão do receptor EGFR (Epidermal Growth Factor Receptor). O ácido gálico (GA), um ácido fenólico natural, tem apresentado vários efeitos biológicos, incluindo atividade anticancerígena, mas seu uso tem algumas limitações principalmente pela alta instabilidade química, levando a uma redução de sua concentração plasmática máxima. Para superar muitos dos problemas de biodisponibilidade, têm-se tornado comum o uso de sistemas de liberação de fármacos (SLF), como as MOFs (Metal-Organic Frameworks), que são polímeros de coordenação inorgânicos porosos sintetizados a partir de íons metálicos e ligantes orgânicos. Neste contexto, vale mencionar as MOFs amorfas (Amorphous Metal-Organic Frameworks), uma subclasse relativamente recente de MOFs construída de maneira bastante semelhante às MOFs convencionais, mas que passam por processos de amorfização físicos ou químicos durante ou após a síntese. Sendo assim, desenvolveu-se uma MOF sintetizada a partir de íons zinco (Zn), um relevante metal e um componente deficiente na próstata acometida pelo câncer, que em seguida foi funcionalizada com cetuximabe (CTX), um anticorpo monoclonal que se liga ao receptor de EGFR, podendo proporcionar a entrega direcionada do GA. O objetivo do presente trabalho foi avaliar o potencial do GA incorporado em MOFs amorfas funcionalizadas com CTX no tratamento do câncer de próstata. Para tanto, sintetizou-se uma MOF híbrida amorfa na presença do GA (aZIF-GA). Após esta etapa, o material foi funcionalizado com CTX (aZIF-GA/CTX) pelo método de conjugação química com os reagentes EDC-NHS. Os materiais obtidos foram devidamente caracterizados, calculada a quantidade de GA incorporado e liberado nos sistemas desenvolvidos (aZIF-GA e aZIF-GA/CTX), onde verificou-se uma eficiência de carga de 81,2% e uma capacidade de carga de 25,6% para o sistema aZIF-GA e de 75,1% e 23,8% para o sistema aZIF-GA/CTX. Os ensaios de liberação foram realizados no meio PBS, com valores de pH 5.0 e 7.4, apresentando maiores taxas de liberação em pH ácido, 88,16% para o sistema não funcionalizado (aZIF-GA) e 81,60% para o sistema funcionalizado (aZIF-GA/CTX). Os estudos de estabilidade demonstraram que os sistemas aZIF-GA e aZIF-GA/CTX possuem excelente estabilidade em meio aquoso. Os ensaios de viabilidade celular 2D, tanto dos precursores quanto dos sistemas (aZIF-GA e aZIF-GA/CTX), foram avaliados em três linhagens celulares de próstata, uma não tumoral (PNT-2) e duas tumorais (PC-3 e DU-145), mostrando maior seletividade para linhagem PC-3. Os ensaios de viabilidade celular 3D foram realizados na linhagem DU-145 e os esferoides apresentaram uma redução da viabilidade de 2,61× para o sistema aZIF-GA e 8,58× para o sistema aZIF-GA/CTX, quando comparados ao GA livre. Os ensaios de internalização celular demonstraram que a morte celular está diretamente relacionada com as alterações celulares oriundas da presença dos compostos testados e o tempo de exposição. Os resultados sugerem o potencial do sistema desenvolvido para o tratamento do câncer de próstata.
Prostate cancer is one of the most common neoplasms and one of the main causes of cancer-related death in men in Brazil and worldwide, constituting a serious public health problem, and the aggressiveness of this neoplasm is mainly related to the overexpression of the EGFR (Epidermal Growth Factor Receptor). Gallic acid (GA) a natural phenolic acid, has shown several biological effects, including anticancer activity, but its use has some limitations mainly due to its high chemical instability, leading to a reduction in its maximum plasma concentration. To overcome many of the bioavailability problems, it has become common to use drug delivery systems (DDS), such as MOFs (Metal-Organic Frameworks), which are porous inorganic coordination polymers synthesized from metal ions and organic linkers. In this context, it is worth mentioning the amorphous MOFs (Amorphous Metal-Organic Frameworks), a relatively recent subclass of MOFs built in a very similar way to conventional MOFs, but that go through physical or chemical amorphization processes during or after synthesis. Thus, a MOF synthesized from zinc ions (Zn) was developed, a relevant metal and a deficient component in the prostate affected by cancer, which was then functionalized with cetuximab (CTX), a monoclonal antibody that binds to the EGFR receptor, which can provide targeted delivery of the GA. The aim of the present study was to evaluate the potential of GA incorporated in amorphous MOFs functionalized with CTX in the treatment of prostate cancer. Therefore, a new amorphous hybrid MOF was synthesized in the presence of GA (aZIF-GA). After this step, the material was functionalized with CTX (aZIF-GA/CTX) by EDC-NHS conjugation chemistry method. The materials obtained were properly characterized, calculated the amount of GA incorporated and released in the developed systems (aZIF-GA and aZIF-GA/CTX) where was verified a load efficiency of 81.2% and a load capacity of 25.6% for the aZIF-GA system and 75.1% and 23.8% for the aZIF-GA/CTX system. The release assays were performed in PBS medium, at pH 5.0 and 7.4, showing higher release rates in acidic pH, 88.16% for the non-functionalized system (aZIF-GA) and 81.60% for the functionalized system (aZIF-GA/CTX). Stability studies demonstrated that aZIF-GA and aZIF-GA/CTX systems have excellent stability in aqueous media. 2D cell viability assays, both precursors and systems (aZIF-GA and aZIF-GA/CTX), were evaluated in three prostate cell lines, one non-tumor (PNT-2) and two tumors (PC-3 and DU-145), showing higher selectivity for PC-3 line. The 3D cell viability assays were performed in the DU-145 line and the spheroids showed a reduction in viability of 2.61× for the aZIF-GA system and 8.58× for the aZIF-GA/CTX system, when compared to free GA. Cell internalization assays demonstrated that cell death is directly related to cell changes arising from the presence of the tested compounds and exposure time. The results suggest the potential of the system developed for the treatment of prostate cancer.
Prostate cancer is one of the most common neoplasms and one of the main causes of cancer-related death in men in Brazil and worldwide, constituting a serious public health problem, and the aggressiveness of this neoplasm is mainly related to the overexpression of the EGFR (Epidermal Growth Factor Receptor). Gallic acid (GA) a natural phenolic acid, has shown several biological effects, including anticancer activity, but its use has some limitations mainly due to its high chemical instability, leading to a reduction in its maximum plasma concentration. To overcome many of the bioavailability problems, it has become common to use drug delivery systems (DDS), such as MOFs (Metal-Organic Frameworks), which are porous inorganic coordination polymers synthesized from metal ions and organic linkers. In this context, it is worth mentioning the amorphous MOFs (Amorphous Metal-Organic Frameworks), a relatively recent subclass of MOFs built in a very similar way to conventional MOFs, but that go through physical or chemical amorphization processes during or after synthesis. Thus, a MOF synthesized from zinc ions (Zn) was developed, a relevant metal and a deficient component in the prostate affected by cancer, which was then functionalized with cetuximab (CTX), a monoclonal antibody that binds to the EGFR receptor, which can provide targeted delivery of the GA. The aim of the present study was to evaluate the potential of GA incorporated in amorphous MOFs functionalized with CTX in the treatment of prostate cancer. Therefore, a new amorphous hybrid MOF was synthesized in the presence of GA (aZIF-GA). After this step, the material was functionalized with CTX (aZIF-GA/CTX) by EDC-NHS conjugation chemistry method. The materials obtained were properly characterized, calculated the amount of GA incorporated and released in the developed systems (aZIF-GA and aZIF-GA/CTX) where was verified a load efficiency of 81.2% and a load capacity of 25.6% for the aZIF-GA system and 75.1% and 23.8% for the aZIF-GA/CTX system. The release assays were performed in PBS medium, at pH 5.0 and 7.4, showing higher release rates in acidic pH, 88.16% for the non-functionalized system (aZIF-GA) and 81.60% for the functionalized system (aZIF-GA/CTX). Stability studies demonstrated that aZIF-GA and aZIF-GA/CTX systems have excellent stability in aqueous media. 2D cell viability assays, both precursors and systems (aZIF-GA and aZIF-GA/CTX), were evaluated in three prostate cell lines, one non-tumor (PNT-2) and two tumors (PC-3 and DU-145), showing higher selectivity for PC-3 line. The 3D cell viability assays were performed in the DU-145 line and the spheroids showed a reduction in viability of 2.61× for the aZIF-GA system and 8.58× for the aZIF-GA/CTX system, when compared to free GA. Cell internalization assays demonstrated that cell death is directly related to cell changes arising from the presence of the tested compounds and exposure time. The results suggest the potential of the system developed for the treatment of prostate cancer.
Descrição
Palavras-chave
Câncer de próstata, MOF, Sistema de liberação de fármaco, Ácido gálico, Cetuximabe, Prostate cancer, Drug delivery system, Gallic acid, Cetuximab