Publications by authors named "Ana Gomes Dos Santos"

Cotadutide (Cota) is a lipidated dual GLP-1 and Glucagon receptor agonist that was investigated for the treatment of various metabolic diseases, it is designed for once daily subcutaneous (SC) administration. Invasive daily injections can result in poor patient compliance with chronic disease, and here, we demonstrate an innovative strategy of encapsulating reversible cota self-assembled fibers within an in-situ forming depot of low molecular weight poly(lactic-co-glycolic) acid (LWPLGA) for sustained delivery GLP-1 and Glucagon receptor agonist with controlled burst release. This could be a suitable alternative to other sustained delivery strategies for fibrillating peptides.

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Lipidated analogues of glucagon-like peptide 1 (GLP-1) have gained enormous attention as long-acting peptide therapeutics for type 2 diabetes and also antiobesity treatment. Commercially available therapeutic lipidated GLP-1 analogues, semaglutide and liraglutide, have the great advantage of prolonged half-lives of hours and days instead of minutes as is the case for native GLP-1. A crucial factor in the development of novel lipidated therapeutic peptides is their physical stability, which greatly influences manufacturing and drug product development.

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Non-natural amino acids are increasingly used as building blocks in the development of peptide-based drugs as they expand the available chemical space to tailor function, half-life and other key properties. However, while the chemical space of modified amino acids (mAAs) such as residues containing post-translational modifications (PTMs) is potentially vast, experimental methods for measuring the developability properties of mAA-containing peptides are expensive and time consuming. To facilitate developability programs through computational methods, we present CamSol-PTM, a method that enables the fast and reliable sequence-based prediction of the intrinsic solubility of mAA-containing peptides in aqueous solution at room temperature.

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Introduction: Oxyntomodulin (Oxm) hormone peptide has a number of beneficial effects on nutrition and metabolism including increased energy expenditure and reduced body weight gain. Despite its many advantages as a potential therapeutic agent, Oxm is subjected to rapid renal clearance and protease degradation limiting its clinical application. Previously, we have shown that subcutaneous administration of a fibrillar Oxm formulation can significantly prolong its bioactivity from a few hours to a few days.

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The physical stability of peptide-based drugs is of great interest to the pharmaceutical industry. Glucagon-like peptide 1 (GLP-1) is a 31-amino acid peptide hormone, the analogs of which are frequently used in the treatment of type 2 diabetes. We investigated the physical stability of GLP-1 and its C-terminal amide derivative, GLP-1-Am, both of which aggregate into amyloid fibrils.

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Article Synopsis
  • Drug-resistant tuberculosis (DR-TB) is a significant public health challenge, with this study focused on evaluating various characteristics and outcomes related to DR-TB in Rio de Janeiro from 2016 to 2020.
  • Out of 148 DR-TB cases, a notable percentage exhibited different levels of drug resistance, with the majority being men under 44, largely from low-income backgrounds and having low educational attainment.
  • Factors like acquired resistance, positive sputum tests, and unemployment were linked to poorer treatment outcomes, underlining the urgent need for targeted public health policies to address DR-TB effectively.
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Introduction: Peptides are widely recognized as therapeutic agents in the treatment of a wide range of diseases, such as cancer and diabetes. However, their use has been limited by their short half-life, due to significant metabolism by exo- and endo-peptidases as well as their inherent poor physical and chemical stability. Research with the aim of improving their half-life in the body and thus improving patient compliance (by decreasing the frequency of injections) has gained significant attention.

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3D printing is an emerging technology aiming towards personalized drug delivery, among many other applications. Microneedles (MN) are a viable method for transdermal drug delivery that is becoming more popular for delivery through the skin. However, there is a need for a faster fabrication process with potential for easily exploring different geometries of MNs.

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The human peptide hormone Oxyntomodulin (Oxm) is known to induce satiety, increase energy expenditure, and control blood glucose in humans, making it a promising candidate for treatment of obesity and/or type 2 diabetes mellitus. However, a pharmaceutical exploitation has thus far been impeded by fast in vivo clearance and the molecule's sensitivity to half-life extending structural modifications. We recently showed that Oxm self-assembles into amyloid-like nanofibrils that continuously release active, soluble Oxm in a peptide-deprived environment.

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Peptide therapeutics have the potential to self-associate, leading to aggregation and fibrillation. Noncovalent PEGylation offers a strategy to improve their physical stability; an understanding of the behavior of the resulting polymer/peptide complexes is, however, required. In this study, we have performed a set of experiments with additional mechanistic insight provided by in silico simulations to characterize the molecular organization of these complexes.

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Lipidation is a powerful strategy to improve the stability in vivo of peptide drugs. Attachment of a lipid chain to a hydrophilic peptide leads to amphiphilicity and the potential for surfactant-like self-assembly. Here, the self-assembly and conformation of three lipidated derivatives of the gastrointestinal peptide hormone PYY is examined using a comprehensive range of spectroscopic, scattering, and electron microscopy methods and compared to those of the parent PYY peptide.

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The purpose of this study was to design microspheres combining sustained delivery and enhanced intracellular penetration for ocular administration of antisense oligonucleotides. Nanosized complexes of antisense TGF-beta2 phosphorothioate oligonucleotides (PS-ODN) with polyethylenimine (PEI), and naked PS-ODN were encapsulated into poly(lactide-co-glycolide) microspheres prepared by the double-emulsion solvent evaporation method. The PS-ODN was introduced either naked or complexed in the inner aqueous phase of the first emulsion.

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Purpose: The aim of this study was to characterize oligonucleotide-polyethylenimine (ODN/PEI) complex preparation for potential transfection of retinal cells in vitro and in vivo.

Methods: The effect of medium preparation [HEPES-buffered saline (HBS), water] on particle size and morphology was evaluated. Cultured Lewis rat retinal Müller glial (RMG) cells were transfected using fluorescein isothiocyanate (FITC)-ODN/PEI complexes specifically directed at transforming growth factor beta (TGFbeta)-2.

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