Ana Rita Oliveira Rodrigues

Magnetoliposomes based on manganese ferrite nanoparticles as nanocarriers for antitumor drugs

Manganese ferrite nanoparticles with a size distribution of 26 ± 7 nm (from TEM measurements) were synthesized by the coprecipitation method. The obtained nanoparticles exhibit a superparamagnetic behaviour at room temperature with a magnetic squareness of 0.016 and a coercivity field of 6.3 Oe. These nanoparticles were either entrapped in liposomes (aqueous magnetoliposomes, AMLs) or covered with a lipid bilayer, forming solid magnetoliposomes (SMLs). Both types of magnetoliposomes, exhibiting sizes below or around 150 nm, were found to be suitable for biomedical applications. Membrane fusion between magnetoliposomes (both AMLS and SMLs) and GUVs (giant unilamellar vesicles), the latter used as models of cell membranes, was confirmed by Forster Resonance Energy Transfer (FRET) assays, using a NBD labeled lipid as the energy donor and Nile Red or rhodamine B-DOPE as the energy acceptor. A potential antitumor thienopyridine derivative was successfully incorporated into both aqueous and solid magnetoliposomes, pointing to a promising application of these systems in oncological therapy, simultaneously as hyperthermia agents and nanocarriers for antitumor drugs.

Magnetoliposomes as carriers for promising antitumor thieno[3,2-b]pyridin-7-arylamines: photophysical and biological studies

Magnetoliposomes containing superparamagnetic manganese ferrite nanoparticles were tested as nanocarriers for two new promising antitumor drugs, a N-(3-methoxyphenyl)thieno[3,2-b]pyridin-7-amine (1) and a N-(2-methoxy-phenyl)thieno[3,2-b]pyridin-7-amine (2). The fluorescence emission of both compounds was studied in different polar and non-polar media, evidencing a strong intramolecular charge transfer character of the excited state of both compounds. These in vitro potent antitumor thienopyridine derivatives were successfully incorporated in both aqueous and solid magnetoliposomes, with encapsulation efficiencies higher than 75%. The magnetic properties of magnetoliposomes containing manganese ferrite nanoparticles were measured for the first time, proving a superparamagnetic behaviour. Growth inhibition assays on several human tumor cell lines showed very low GI50 values for drug-loaded aqueous magnetoliposomes, comparing in most cell lines with the ones previously obtained using the neat compounds. These results are important for future drug delivery applications using magnetoliposomes in oncology, through a dual therapeutic approach (simultaneous chemotherapy and magnetic hyperthermia).

Solid and aqueous magnetoliposomes as nanocarriers for a new potential drug active against breast cancer

Iron oxide nanoparticles, with diameters around 12nm, were synthesized by coprecipitation method. The magnetic properties indicate a superparamagnetic behavior with a coercive field of 9.7Oe and a blocking temperature of 118K. Both aqueous and solid magnetoliposomes containing magnetite nanoparticles have sizes below 150nm, suitable for biomedical applications. Interaction between both types of magnetoliposomes and models of biological membranes was proven. A new antitumor compound, a diarylurea derivative of thienopyridine, active against breast cancer, was incorporated in both aqueous and solid magnetoliposomes, being mainly located in the lipid membrane. A promising application of these magnetoliposomes in oncology is anticipated, allowing a combined therapeutic approach, using both chemotherapy and magnetic hyperthermia.

A Deep Learning Approach to Case Based Reasoning to the Evaluation and Diagnosis of Cervical Carcinoma

Deep Learning (DL) is a new area of Machine Learning research introduced with the objective of moving Machine Learning closer to one of its original goals, i.e., Artificial Intelligence (AI). DL breaks down tasks in ways that makes all kinds of machine assists seem possible, even likely. Better preventive healthcare, even better recommendations, are all here today or on the horizon. However, keeping up the pace of progress will require confronting currently AI’s serious limitations. The last but not the least, Cervical Carcinoma is actuality a critical public health problem. Although patients have a longer survival rate due to early diagnosis and more effective treatment, this disease is still the leading cause of cancer death among women. Therefore, the main objective of this article is to present a DL approach to Case Based Reasoning in order to evaluate and diagnose Cervical Carcinoma using Magnetic Resonance Imaging. It will be grounded on a dynamic virtual world of complex and interactive entities that compete against one another in which its aptitude is judged by a single criterion, the Quality of Information they carry and the system’s Degree of Confidence on such a measure, under a fixed symbolic structure.

Magnetoliposomes containing magnesium ferrite nanoparticles as nanocarriers for the model drug curcumin

Magnesium ferrite nanoparticles, with diameters around 25 nm, were synthesized by coprecipitation method. The magnetic properties indicate a superparamagnetic behaviour, with a maximum magnetization of 16.2 emu g−1, a coercive field of 22.1 Oe and a blocking temperature of 183.2 K. These MgFe2O4 nanoparticles were used to produce aqueous and solid magnetoliposomes, with sizes below 130 nm. The potential drug curcumin was successfully incorporated in these nanosystems, with high encapsulation efficiencies (above 89%). Interaction by fusion between both types of drug-loaded magnetoliposomes (with or without PEGylation) and models of biological membranes was demonstrated, using FRET or fluorescence quenching assays. These results point to future applications of magnetoliposomes containing MgFe2O4 nanoparticles in cancer therapy, allowing combined magnetic hyperthermia and chemotherapy.

Magnetoliposomes for dual cancer therapy

Abstract Liposomes can overcome many of the problems associated with other systems used in therapy, such as problems involving solubility, toxicity, pharmacokinetics, and in vivo stability. However, this system still presents some issues for in vivo application, namely its recognition and capture by the immune system and the location in therapeutic sites for drug release. In order to overcome these problems, magneto-sensitive liposomes have been proposed. The magnetic components allow the concentration of the liposomes in the desired area of the patient organs by magnetic forces. Therefore, a new therapy is emerging, involving the magnetically guided transport of drugs (most of them toxic and with systemic side effects), and focusing them in specific sites of the human body. Magneto-sensitive liposomes result from the encapsulation of magnetic nanoparticles into liposomes. The so-called magnetoliposomes combine the amazing physical properties of these two types of nanosystems and preserve the magnetic properties of the nanoparticles. This ideal nanocarrier can be used in a wide array of biomedical applications. In therapy, the most promising applications of magnetoliposomes are magnetic-guided drug delivery and hyperthermia. Furthermore, in diagnosis, magnetic nanoparticles have been used as contrast agents in magnetic resonance imaging. The magnetic nanoparticles can be either entrapped in liposomes, creating aqueous magnetoliposomes, or covered with a lipid bilayer, forming solid (or dry) magnetoliposomes. Both aqueous and solid magnetoliposomes have been used as nanocarriers for new and well-established anticancer drugs. This chapter describes the synthesis, characterization, and applications of magnetoliposomes in cancer therapy, both by antitumor drug delivery and hyperthermia, as well as the ability to attain magnetic guidance to the therapeutic sites of interest.

Evaluating the Prophylaxis of the Risk of Deep Vein ThrombosisU sing Business Intelligence

Deep Vein Thrombosis (DVT) consists in the formation of a blood clot within the deep veins of the lower limbs. This study explores the data and information collected from the Electronic Health Record of a Health Care Institution. Several concepts such as Data Warehouse, Extract-Transform-Load and Business Intelligence were applied and the use of these technological systems was aimed at obtaining indicators that provide a comprehensive overview from the data collected and assist in decision making. Of all the patients analysed, 11,042 did not obtain any type of prophylaxis, 4508 received pharmacological prophylaxis with low molecular weight heparin (LMWH), 1260 got mechanical prophylaxis and 1119 had to contact the Haematology department. The results achieved allow building a system able to identify low use of prophylaxis and the need to alert health professionals to the importance of these measures in prevention of the DVT disease.