University of Madeira

About: University of Madeira is a education organization based out in Funchal, Portugal. It is known for research contribution in the topics: Population & Dendrimer. The organization has 1014 authors who have published 2759 publications receiving 59457 citations.

Volatile metabolomic signature of human breast cancer cell lines.

Abstract: Breast cancer (BC) remains the most prevalent oncologic pathology in women, causing huge psychological, economic and social impacts on our society. Currently, the available diagnostic tools have limited sensitivity and specificity. Metabolome analysis has emerged as a powerful tool for obtaining information about the biological processes that occur in organisms, and is a useful platform for discovering new biomarkers or make disease diagnosis using different biofluids. Volatile organic compounds (VOCs) from the headspace of cultured BC cells and normal human mammary epithelial cells, were collected by headspace solid-phase microextraction (HS-SPME) and analyzed by gas chromatography combined with mass spectrometry (GC-MS), thus defining a volatile metabolomic signature. 2-Pentanone, 2-heptanone, 3-methyl-3-buten-1-ol, ethyl acetate, ethyl propanoate and 2-methyl butanoate were detected only in cultured BC cell lines. Multivariate statistical methods were used to verify the volatomic differences between BC cell lines and normal cells in order to find a set of specific VOCs that could be associated with BC, providing comprehensive insight into VOCs as potential cancer biomarkers. The establishment of the volatile fingerprint of BC cell lines presents a powerful approach to find endogenous VOCs that could be used to improve the BC diagnostic tools and explore the associated metabolomic pathways.

Polyaniline-loaded γ-polyglutamic acid nanogels as a platform for photoacoustic imaging-guided tumor photothermal therapy.

Abstract: We report the facile synthesis of polyaniline (PANI)-loaded γ-polyglutamic acid (γ-PGA) nanogels (NGs) for photoacoustic (PA) imaging-guided photothermal therapy (PTT) of tumors. In this work, γ-PGA NGs were first formed via a double emulsion approach, followed by crosslinking with cystamine dihydrochloride (Cys) via 1-ethyl-3-[3-dimethylaminopropyl]carbodiimide hydrochloride coupling chemistry. The formed γ-PGA/Cys NGs were employed as a nanoreactor to load aniline monomers via an electrostatic interaction for subsequent in situ polymerization in the presence of ammonium persulfate. The resulting γ-PGA/Cys@PANI NGs were thoroughly characterized. It is shown that the γ-PGA/Cys@PANI NGs with an average size of 71.9 nm are dispersible in water, colloidally stable, and cytocompatible and hemocompatible in the concentration range studied. The strong near-infrared (NIR) absorbance renders the NGs with good PA imaging contrast enhancement and photothermal conversion properties. With these excellent properties and biocompatibility, the developed γ-PGA/Cys@PANI NGs are able to be used for PA imaging-guided PTT of cancer cells in vitro and a xenografted tumor model in vivo. This unique theranostic nanoplatform may be further loaded with other imaging or therapeutic elements, or modified with targeting ligands, thereby providing a ubiquitous platform for multimode imaging and combinational therapy of different biosystems.

Dendrimer-entrapped gold nanoparticles modified with folic acid for targeted gene delivery applications

Abstract: We report a new use of dendrimer-entrapped gold nanoparticles (Au DENPs) modified with folic acid (FA) as a non-viral vector for targeted gene delivery applications. In this study, amine-terminated generation 5 poly(amidoamine) dendrimers modified with FA via covalent conjugation were used as templates to synthesize gold nanoparticles with an Au salt/dendrimer molar ratio of 25 : 1. The synthesized FA-modified Au DENPs (Au DENPs-FA) were used as a non-viral vector for the delivery of plasmid DNA (pDNA) into a model cancer cell line (HeLa cells) overexpressing high-affinity FA receptors (FAR). The DNA compaction ability of the formed Au DENPs-FA was systematically characterized using a gel retardation assay, zeta potential, and dynamic light scattering. We show that similar to the Au DENPs vector without FA, the Au DENPs-FA vector was able to compact the pDNA encoding enhanced green fluorescent protein (EGFP) at an N/P ratio of 0.5. Transfection results show that the Au DENPs-FA vector enables much higher luciferase and EGFP gene expression in HeLa cells overexpressing FAR than the Au DENPs without FA, demonstrating the role played by FA-mediated targeting for enhanced gene transfection in target cells. With a lower cytotoxicity than that of the Au DENPs without FA proven by a cell viability assay, the developed FA-modified Au DENPs may be used as a promising non-viral vector for safe and targeted gene therapy applications.