Hélder A Santos

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Mesoporous silicon particles hold great potential in improving the solubility of otherwise poorly soluble drugs. To effectively translate this feature into the clinic, especially via oral or parenteral administration, a thorough understanding of the interactions of the micro- and nanosized material with the physiological environment during the delivery(More)
Porous silicon (PSi) particles have been studied for the effects they elicit in Caco-2 and RAW 264.7 macrophage cells in terms of toxicity, oxidative stress, and inflammatory response. The most suitable particles were then functionalized with a novel (18)F label to assess their biodistribution after enteral and parenteral administration in a rat model. The(More)
Diabetes mellitus is a high prevalence and one of the most severe and lethal diseases in the world. Insulin is commonly used to treat diabetes in order to give patients a better life condition. However, due to bioavailability problems, the most common route of insulin administration is the subcutaneous route, which may present patients compliance problems(More)
Despite steadily increasing insights on the biocompatibility of PSi nanoparticles (NPs), an extensive biosafety study on the immune and red blood cells (RBCs) is still lacking. Herein, we evaluated the impact of the PSi NPs' surface chemistry on immune cells and human RBCs both in vitro and in vivo. Negatively charged hydrophilic and hydrophobic PSi NPs(More)
Cytotoxicity of ordered mesoporous silica MCM-41 and SBA-15 microparticles (fractions between 1 and 160 microm) was determined in vitro on undifferentiated human colon carcinoma (Caco-2) cell line, considering the feasibility of using these silica-based materials in oral drug formulations. The cellular endpoints employed for assessing the effects of the(More)
Rapid immune recognition and subsequent elimination from the circulation hampers the use of many nanomaterials as carriers to targeted drug delivery and controlled release in the intravenous route. Here, we report the effect of a functional self-assembled protein coating on the intravenous biodistribution of (18)F-labeled thermally hydrocarbonized porous(More)
Glucagon like peptide-1 (GLP-1) is an incretin hormone that is in the pipeline for type 2 diabetes mellitus (T2DM) therapy. However, oral administration of GLP-1 is hindered by the harsh conditions of the gastrointestinal tract and poor bioavailability. In this study, three nanosystems composed by three different biomaterials (poly(lactide-co-glycolide)(More)
A poorly soluble model drug, indomethacin (IMC), was loaded into two types of silica particles using three different loading methods. The loading efficiency and the extent/rate of drug release were evaluated. Widely used equipment in pharmaceutical laboratories, rotavapor and fluid bed, were used in the loading. The porous materials used were ordered(More)
Cocrystallization and salt formation have been shown to entail substantial promise in tailoring the physicochemical properties of drug compounds, in particular, their dissolution and hygroscopicity. In this work, we report on the preparation and comparative evaluation of a new cocrystal of itraconazole and malonic acid and two new hydrochloric salts(More)
Porous silicon (PSi) particles have been widely used in modulating the dissolution rate of various types of drugs loaded within its mesopores. This material can be surface treated in order to vary its hydrophobicity and several other properties, such as drug loading degree and release rate. Hydrophobins are a family of self-assembling proteins of fungal(More)