Publications by authors named "Guillermo R Castro"

Hot-melt extrusion (HME) has emerged as a versatile and efficient technique in pharmaceutical formulation development, particularly for enhancing the solubility and bioavailability of poorly water-soluble drugs. This review delves into the fundamental principles of HME, exploring its application in drug delivery systems. A comprehensive analysis of polymers utilized in HME, such as hydroxypropyl methylcellulose, ethyl cellulose, hydroxypropyl cellulose, and polyvinylpyrrolidone, is presented, highlighting their roles in achieving controlled drug release and improved stability.

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Microalgae are susceptible to most pollutants in aquatic ecosystems and can be potentially damaged by silver nanoparticles (AgNPs). This study aims to clarify the potential consequences of Chlorella vulgaris internalizing AgNPs. The exposure of C.

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Konjac glucomannan (KG) is a dietary fiber hydrocolloid derived from Amorphophallus konjac tubers and is widely utilized as a food additive and dietary supplement. As a health-conscious choice, purified KG, along with konjac flour and KG-infused diets, have gained widespread acceptance in Asian and European markets. An overview of the chemical composition and structure of KG is given in this review, along with thorough explanations of the processes used in its extraction, production, and purification.

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Pectin hydrogels have emerged as a highly promising medium for the controlled release of pharmaceuticals in the dynamic field of drug delivery. The present review sheds light on the broad range of applications and potential of pectin-based hydrogels in pharmaceutical formulations. Pectin, as a biopolymer, is a versatile candidate for various drug delivery systems because of its wide range of properties and characteristics.

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In this work, scaffolds based on poly(hydroxybutyrate) (PHB) and micronized bacterial cellulose (BC) were produced through 3D printing. Filaments for the printing were obtained by varying the percentage of micronized BC (0.25, 0.

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Plant and herbal essential oils (EOs) offer a wide range of pharmacological actions that include anticancer effects. Here, we evaluated the cytotoxic activity of EO from (chemotype linalool), (chemotype dihydrocarvone, LaDEO), (L.) (CnEO), , × , × , L.

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Chagas disease is a neglected endemic disease prevalent in Latin American countries, affecting around 8 million people. The first-line treatment, benznidazole (BNZ), is effective in the acute stage of the disease but has limited efficacy in the chronic stage, possibly because current treatment regimens do not eradicate transiently dormant amastigotes. Nanostructured lipid carriers (NLC) appear to be a promising approach for delivering pharmaceutical active ingredients as they can have a positive impact on bioavailability by modifying the absorption, distribution, and elimination of the drug.

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Article Synopsis
  • * Researchers developed three types of nanoparticles using 8-QO-Pt and riboflavin (RFV), which were created to be small and effective in delivering the drug; these nanoparticles had a size range of 144-175 nm and maintained a strong encapsulation efficiency.
  • * The study found that these RFV-targeted nanoparticles were more cytotoxic to colorectal cancer cells than the free 8-QO-Pt drug, while also showing a good safety profile, indicating their potential for
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Bacterial cellulose (BC) is produced by several microorganisms as extracellular structures and can be modified by various physicochemical and biological strategies to produce different cellulosic formats. The main advantages of BC for biomedical applications can be summarized thus: easy moldability, purification, and scalability; high biocompatibility; and straightforward tailoring. The presence of a high amount of free hydroxyl residues, linked with water and nanoporous morphology, makes BC polymer an ideal candidate for wound healing.

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  • * This study developed a cost-effective spectrophotometric method at 514 nm to quantify VCZ simply and effectively, showing a linear response within a specified concentration range.
  • * The new method not only confirmed existing degradation products of VCZ but also identified a novel product, improving quantification stability and facilitating VCZ detection in tablets and human plasma.
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Nitric oxide (NO) is an important endogenous molecule that plays several roles in biological systems. NO is synthesized in human skin by three isoforms of nitric oxide synthase (NOS) and, depending on the produced NO concentration, it can actuate in wound healing, dermal vasodilation, or skin defense against different pathogens, for example. Besides being endogenously produced, NO-based pharmacological formulations have been developed for dermatological applications targeting diverse pathologies such as bacterial infection, wound healing, leishmaniasis, and even esthetic issues such as acne and skin aging.

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Vitamin E (VitE) is one of the most important antioxidants and plays a key role in decreasing the inflammatory effects of oxidative stress caused by recurrent doses of iron administration in anemia treatment. However, VitE is poorly soluble in aqueous environments. Here, VitE encapsulation into solid lipid nanoparticles (SLN) composed of myristil myristate to improve its bioavailability was proposed.

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  • * Researchers developed lipid-based nanoparticles, specifically nanostructured lipid carriers (NLCs), to enhance drug delivery and improve permeability of the antiepileptic drug phenobarbital without causing toxicity.
  • * The optimized NLCs were characterized by favorable properties like size (~178 nm) and high entrapment efficiency (98.2%), and showed prolonged drug release and non-toxic effects in tests, indicating potential effectiveness in treating seizures.
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Liver inflammation represents a major clinical problem in a wide range of pathologies. Among the strategies to prevent liver failure, dexamethasone (DXM) has been widely used to suppress inflammatory responses. The use of nanocarriers for encapsulation and sustained release of glucocorticoids to liver cells could provide a solution to prevent severe side effects associated with systemic delivery as the conventional treatment regime.

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Violacein (Viol) is a bacterial purple water-insoluble pigment synthesized by and other microorganisms that display many beneficial therapeutic properties including anticancer activity. Viol was produced, purified in our laboratory, and encapsulated in a nanostructured lipid carrier (NLC). The NLC is composed of the solid lipid myristyl myristate, an oily lipid mixture composed of capric and caprylic acids, and the surfactant poloxamer P188.

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Pigments are among the most fascinating molecules found in nature and used by human civilizations since the prehistoric ages. Although most of the bio-dyes reported in the literature were discovered around the eighties, the necessity to explore novel compounds for new biological applications has made them resurface as potential alternatives. Prodigiosin (PG) is an alkaloid red bio-dye produced by diverse microorganisms and composed of a linear tripyrrole chemical structure.

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This study aimed to encapsulate and characterise a potential anti-tuberculosis copper complex (CuCl(INH).HO:) into polymeric nanoparticles (PNs) of polymethacrylate copolymers (Eudragit®, Eu) developed by nanoprecipitation method. NE30D, S100 and, E100 polymers were tested.

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The aim of the current review is to address updated research on a natural pigment called violacein, with emphasis on its production, biological activity and applications. New information about violacein's action mechanisms as antitumor agent and about its synergistic action in drug delivery systems has brought new alternatives for anticancer therapy. Thus, violacein is introduced as reliable drug capable of overcoming at least three cancer hallmarks, namely: proliferative signaling, cell death resistance and metastasis.

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Agro-industrial wastes to be a global concern since agriculture and industrial processes are growing exponentially with the fast increase of the world population. Biopolymers are complex molecules produced by living organisms, but also found in many wastes or derived from wastes. The main drawbacks for the use of polymers are the high costs of the polymer purification processes from waste and the scale-up in the case of biopolymer production by microorganisms.

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The three main FDA-approved platinum drugs in chemotherapy such as carboplatin, cisplatin, and oxaliplatin are extensively applied in cancer treatments. Although the clinical applications of platinum-based drugs are extremely effective, their toxicity profile restricts their extensive application. Therefore, recent studies focus on developing new platinum drug formulations, expanding the therapeutic aspect.

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Antigen formulation is the main feature for the success of leishmaniosis diagnosis and vaccination, since the disease is caused by different parasite species that display particularities which determine their pathogenicity and virulence. It is desirable that the antigens are recognized by different antibodies and are immunogenic for almost all species. To overcome this problem, we selected six potentially immunogenic peptides derived from histones and parasite membrane molecules obtained by phage display or spot synthesis and entrapped in liposome structures.

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