Alternative techniques for the pretreatment of human fluids and extraction of tumor biomarkers to improve diagnosis

• Autores: Marguerita Evangelho da Rosa
• Directores de la Tesis: Mara Guadalupe Freire Martins (dir. tes.), João Pereira Coutinho (dir. tes.), Ana Francisca Osorio de Almeida Coelho e Silva (dir. tes.)
• Lectura: En la Universidade de Aveiro (UA) ( Portugal ) en 2023
• Idioma: inglés
• Títulos paralelos:
  • Técnicas alternativas de pré-tratamento de fluidos humanos e extração de biomarcadores tumorais visando melhorias de diagnóstico
• Tribunal Calificador de la Tesis: Verónica Pino Estévez (voc.)
• Enlaces
  • Tesis en acceso abierto en: hdl.handle.net
• Resumen

  • Cancer is considered one of the main hurdles against a higher life expectancy. Aiming to improve this negative impact, the quantification of cancer biomarkers in human fluids is a promising strategy for the early detection Cancer is considered one of the main hurdles against a higher life expectancy. Aiming to improve this negative impact, the quantification of cancer biomarkers in human fluids is a promising strategy for the early detection of cancer, contributing to improve the overall patients’ survival rate. However, the quantification of biomarkers in human fluids is a complex task, and its efficiency depends on sample complexity and biomarker concentration. To ease this task, there is a need for a sample pretreatment step in order to reduce the interference of more abundant biomolecules in the quantification and extraction of the biomarkers of interest. In this work, alternative pretreatment strategies were developed and optimized according to the type of human fluid (human serum and saliva) and cancer biomarkers (proteins and volatile organic compounds). In a first step, three-phase partition systems based on aqueous biphasic systems (ABS-TPP) were developed using several components for the pretreatment of human serum. The efficiency of ABS-TPP in pretreatment was evaluated for its ability to deplete immunoglobulin G and human serum albumin (HSA) - the most abundant proteins in human serum - and to extract three protein biomarkers of lung and prostate cancers (CYFRA 21-1, prostate-specific antigen, PSA, and pentraxin-3, PTX-3). In a second approach, solid phase microextraction (SPME) was used for the selective extraction of volatile organic compounds - VOCs - from saliva. According to the results, the proposed approaches showed potential to improve the extraction and subsequent analysis of biomarkers from human fluids and may contribute to an early diagnosis of cancer.of cancer, contributing to improve the overall patients’ survival rate. However, the quantification of biomarkers in human fluids is a complex task, and its efficiency depends on sample complexity and biomarker concentration. To ease this task, there is a need for a sample pretreatment step in order to reduce the interference of more abundant biomolecules in the quantification and extraction of the biomarkers of interest. In this work, alternative pretreatment strategies were developed and optimized according to the type of human fluid (human serum and saliva) and cancer biomarkers (proteins and volatile organic compounds). In a first step, three-phase partition systems based on aqueous biphasic systems (ABS-TPP) were developed using several components for the pretreatment of human serum. The efficiency of ABS-TPP in pretreatment was evaluated for its ability to deplete immunoglobulin G and human serum albumin (HSA) - the most abundant proteins in human serum - and to extract three protein biomarkers of lung and prostate cancers (CYFRA 21-1, prostate-specific antigen, PSA, and pentraxin-3, PTX-3). In a second approach, solid phase microextraction (SPME) was used for the selective extraction of volatile organic compounds - VOCs - from saliva. According to the results, the proposed approaches showed potential to improve the extraction and subsequent analysis of biomarkers from human fluids and may contribute to an early diagnosis of cancer.