Browsing by Author "Reis, Catarina"
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- Experimental Murine Models for Colorectal Cancer ResearchPublication . Neto, Íris; Rocha, Joao; Gaspar, Maria Manuela; Reis, CatarinaSimple Summary In its early stages, colorectal cancer (CRC) is a localized tumor, but when it metastasizes, it has dramatic consequences. Murine models in CRC research are important tools for advancing the knowledge in diagnostic and treatment of this pathology. The present review aims to provide a variety of murine models in CRC research describing their particular advantages and drawbacks. Abstract Colorectal cancer (CRC) is the third most prevalent malignancy worldwide and in both sexes. Numerous animal models for CRC have been established to study its biology, namely carcinogen-induced models (CIMs) and genetically engineered mouse models (GEMMs). CIMs are valuable for assessing colitis-related carcinogenesis and studying chemoprevention. On the other hand, CRC GEMMs have proven to be useful for evaluating the tumor microenvironment and systemic immune responses, which have contributed to the discovery of novel therapeutic approaches. Although metastatic disease can be induced by orthotopic injection of CRC cell lines, the resulting models are not representative of the full genetic diversity of the disease due to the limited number of cell lines suitable for this purpose. On the other hand, patient-derived xenografts (PDX) are the most reliable for preclinical drug development due to their ability to retain pathological and molecular characteristics. In this review, the authors discuss the various murine CRC models with a focus on their clinical relevance, benefits, and drawbacks. From all models discussed, murine CRC models will continue to be an important tool in advancing our understanding and treatment of this disease, but additional research is required to find a model that can correctly reflect the pathophysiology of CRC.
- Growth performance, in vitro antioxidant properties and chemical composition of the halophyte Limonium algarvense Erben are strongly influenced by the irrigation salinityPublication . Rodrigues, Maria João; Monteiro, Ivo; Castañeda-Loaiza, Viana; Placines, Chloe; Oliveira, M.Conceição; Reis, Catarina; Caperta, Ana; Soares, Florbela; Pousão-Ferreira, Pedro; Pereira, Catarina; Custódio, LuísaLimonium algarvense Erben (sea lavender) is a halophyte species with potential to provide natural ingredients with in vitro antioxidant, anti-inflammatory, neuroprotective and antidiabetic properties. This study reports for the first time the 1) cultivation of sea lavender in greenhouse conditions under irrigation with freshwater (approx. 0mM NaCl) and saline aquaculture wastewater (300 and 600mM NaCl), and 2) the influence of the irrigation salinity on the plant performance (e.g. growth, number of produced leaves and flowers), in vitro antioxidant properties [radical scavenging activity (DPPH and ABTS), ferric reducing antioxidant power (FRAP), metal chelating properties on copper (CCA) and iron (ICA)], toxicity (in vitro on three mammalian cell lines) and chemical composition (determined by LC-ESI-HRMS/MS). The freshwater-irrigated plants had better growth performance than those irrigated with saltwater. Extracts from wild plants, had the highest antioxidant activity, but those from cultivated ones kept high in vitro antioxidant properties and interesting chemical profile. The flowers’ extracts of plants irrigated with 300mM NaCl had the highest antioxidant activities against DPPH, whereas those from freshwater-irrigated plants were more active on ABTS, CCA and FRAP. Most of the extracts showed nil toxicity. The flowers’ extracts displayed the highest diversity of compounds, mainly quercetin, apigenin, luteolin, naringenin and their glycoside derivatives. Moreover, their abundance varied with the irrigation salinity. These data indicate that sea lavender plants can be successfully cultivated in greenhouse conditions under fresh- and saltwater irrigation, maintaining interesting biological and chemical properties
- A Novel Hybrid Nanosystem Integrating Cytotoxic and Magnetic Properties as a Tool to Potentiate Melanoma TherapyPublication . Cruz, Nuno; Pinho, Jacinta Oliveira; Soveral, Graça; Ascensão, Lia; Matela, Nuno; Reis, Catarina; Gaspar, Maria ManuelaCancer is a major health concern and the prognosis is often poor. Significant advances in nanotechnology are now driving a revolution in cancer detection and treatment. The goal of this study was to develop a novel hybrid nanosystem for melanoma treatment, integrating therapeutic and magnetic targeting modalities. Hence, we designed long circulating and pH-sensitive liposomes loading both dichloro(1,10-phenanthroline) copper (II) (Cuphen), a cytotoxic metallodrug, and iron oxide nanoparticles (IONPs). The synthetized IONPs were characterized by transmission electron microscopy and dynamic light scattering. Lipid-based nanoformulations were prepared by the dehydration rehydration method, followed by an extrusion step for reducing and homogenizing the mean size. Liposomes were characterized in terms of incorporation parameters and mean size. High Cuphen loadings were obtained and the presence of IONPs slightly reduced Cuphen incorporation parameters. Cuphen antiproliferative properties were preserved after association to liposomes and IONPs (at 2 mg/mL) did not interfere on cellular proliferation of murine and human melanoma cell lines. Moreover, the developed nanoformulations displayed magnetic properties. The absence of hemolytic activity for formulations under study demonstrated their safety for parenteral administration. In conclusion, a lipid-based nanosystem loading the cytotoxic metallodrug, Cuphen, and displaying magnetic properties was successfully designed.
- Preliminary Assays towards Melanoma Cells Using Phototherapy with Gold-Based NanomaterialsPublication . Lopes, Joana; Coelho, João Miguel Pinto; Vieira, Pedro Manuel Cardoso; Viana, Ana Silveira; Gaspar, Maria Manuela; Reis, CatarinaCancer like melanoma is a complex disease, for which standard therapies have significant adverse side effects that in most cases are ineffective and highly unspecific. Thus, a new paradigm has come with the need of achieving alternative (less invasive) and effective therapies. In this work, biocompatible gold nanoparticles (GNPs) coated with hyaluronic acid and oleic acid were prepared and characterized in terms of size, morphology and cytotoxicity in the presence of Saccharomyces cerevisiae, and two cell lines, the keratinocytes (healthy skin cells, HaCat) and the melanoma cells (B16F10). Results showed that these GNPs absorb within the near-infrared region (750–1400 nm), in the optical therapeutic window (from 650 to 1300 nm), in contrast to other commercial gold nanoparticles, which enables light to penetrate into deep skin layers. A laser emitting in this region was applied and its effect also analyzed. The coated GNPs showed a spherical morphology with a mean size of 297 nm without cytotoxic effects towards yeast and tested cell lines. Nevertheless, after laser irradiation, a reduction of 20% in B16F10 cell line viability was observed. In summary, this work appears to be a promising strategy for the treatment of non-metastatic melanoma or other superficial tumors.