RESUMO
In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.
Assuntos
Alginatos , Liberação Controlada de Fármacos , Ácido Hialurônico , Hidrogéis , Nanopartículas , Alginatos/química , Ácido Hialurônico/química , Hidrogéis/química , Nanopartículas/química , Administração Oral , Portadores de Fármacos/química , Humanos , Hidróxidos/química , Curcumina/química , Curcumina/administração & dosagem , Curcumina/farmacologia , Metilprednisolona/química , Metilprednisolona/administração & dosagem , Sistemas de Liberação de Medicamentos , Colite Ulcerativa/tratamento farmacológicoRESUMO
Chronic Kidney Disease (CKD) which involves gradual loss of kidney function is characterized by low levels of a glycoprotein called Erythropoietin (EPO) that leads to red blood cell deficiency and anemia. Recombinant human EPO (rhEPO) injections that are administered intravenously or subcutaneously is the current gold standard for treating CKD. The rhEPO injections have very short half-lives and thus demands frequent administration with a risk of high endogenous EPO levels leading to severe side effects that could prove fatal. To this effect, this work provides a novel approach of using lamellar inorganic solids with a brucite-like structure for controlling the release of protein therapeutics such as rhEPO in injectable hydrogels. The nanoengineered injectable system was formulated by incorporating two-dimensional layered double hydroxide (LDH) clay materials with a high surface area into alginate hydrogels for sustained delivery. The inclusion of LDH in the hydrogel network not only improved the mechanical properties of the hydrogels (5-30 times that of alginate hydrogel) but also exhibited a high binding affinity to proteins without altering their bioactivity and conformation. Furthermore, the nanoengineered injectable hydrogels (INHs) demonstrated quick gelation, injectability, and excellent adhesion properties on human skin. The in vitro release test of EPO from conventional alginate hydrogels (Alg-Gel) showed 86% EPO release within 108 h while INHs showed greater control over the initial burst and released only 24% of EPO in the same incubation time. INH-based ink was successfully used for 3D printing, resulting in scaffolds with good shape fidelity and stability in cell culture media. Controlled release of EPO from INHs facilitated superior angiogenic potential in ovo (chick chorioallantoic membrane) compared to Alg-Gel. When subcutaneously implanted in albino mice, the INHs formed a stable gel in vivo without inducing any adverse effects. The results suggest that the proposed INHs in this study can be utilized as a minimally invasive injectable platform or as 3D printed patches for the delivery of protein therapeutics to facilitate tissue regeneration.
Assuntos
Hidrogéis , Insuficiência Renal Crônica , Camundongos , Animais , Humanos , Hidrogéis/química , Engenharia Tecidual/métodos , Preparações de Ação Retardada/farmacologia , Alginatos/química , HidróxidosRESUMO
The advancement of artificial intelligence in education (AIED) has the potential to transform the educational landscape and influence the role of all involved stakeholders. In recent years, the applications of AIED have been gradually adopted to progress our understanding of students' learning and enhance learning performance and experience. However, the adoption of AIED has led to increasing ethical risks and concerns regarding several aspects such as personal data and learner autonomy. Despite the recent announcement of guidelines for ethical and trustworthy AIED, the debate revolves around the key principles underpinning ethical AIED. This paper aims to explore whether there is a global consensus on ethical AIED by mapping and analyzing international organizations' current policies and guidelines. In this paper, we first introduce the opportunities offered by AI in education and potential ethical issues. Then, thematic analysis was conducted to conceptualize and establish a set of ethical principles by examining and synthesizing relevant ethical policies and guidelines for AIED. We discuss each principle and associated implications for relevant educational stakeholders, including students, teachers, technology developers, policymakers, and institutional decision-makers. The proposed set of ethical principles is expected to serve as a framework to inform and guide educational stakeholders in the development and deployment of ethical and trustworthy AIED as well as catalyze future development of related impact studies in the field.
RESUMO
Genetic engineering of the filamentous fungus Aspergillus oryzae still requires more suitable selection markers for fungal transformation. Our previous work has shown that Agrobacterium tumefaciens-mediated transformation (ATMT) based on the uridine/uracil auxotrophic mechanism with pyrG as the selection marker is very efficient for gene transfer in A. oryzae. In the present study, we delete the hisB gene, which is essential for histidine biosynthesis, in A. oryzae via homologous recombination and demonstrate that hisB is a reliable selection marker for genetic transformation of this fungus. Under optimal conditions, the ATMT efficiency of the histidine auxotrophic A. oryzae reached 515 transformants per 106 spores. Especially, we have succeeded in constructing a new ATMT system based on dual auxotrophic A. oryzae mutants with two different selection markers including hisB and pyrG. This dual auxotrophic ATMT system displayed a transformation efficiency of 232 transformants per 106 spores for the hisB marker and 318 transformants per 106 spores for the pyrG marker. By using these selectable markers, the co-expression of the DsRed and GFP fluorescent reporter genes was implemented in a single fungal strain. Furthermore, we could perform both the deletion and complementation of the laeA regulatory gene in the same strain of A. oryzae to examine its function. Conclusively, the ATMT system constructed in our work represents a promising genetic tool for studies on recombinant expression and gene function in the industrially important fungus A. oryzae.