Percorrer por autor "Soares, Raquel"
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- Advancing diabetes treatment: from human beta cell technology to bioartificial pancreas developmentPublication . Sá, Joana; Sá, Simone; Leménager, Hélène; Costa, Raquel; Onteniente, Brigitte; Soares, Raquel; Ribeiro, Viviana P.; Oliveira, Ana L.In 2021, approximately 537 million people worldwide, primarily in low- and middle-income countries, were affected by diabetes, leading to approximately 6.7 million deaths annually or severe secondary complications including life-threatening hyperglycemia. For nearly 50 years, current therapeutic approaches include full pancreas transplantation and isolated pancreatic islets, more recently, cell therapy such as in vitro generated islets and stem cell derived. The transplantation of pancreatic islet cells can be less invasive than full organ transplantation, however, does not achieve the same rate of functional success due to the low survival of the engrafted cells. Tissue-engineered bioartificial pancreas has been designed to address such issues, improving cell engraftment, survival, and immune rejection problems, with the added advantage that the tissue produced in vitro has an unlimited source of material.
- Exploring silk Sericin for diabetic wounds: an in situ-forming hydrogel to protect against oxidative stress and improve tissue healing and regenerationPublication . Baptista-Silva, Sara; Bernardes, Beatriz G.; Borges, Sandra; Rodrigues, Ilda; Fernandes, Rui; Gomes-Guerreiro, Susana; Pinto, Marta Teixeira; Pintado, Manuela; Soares, Raquel; Costa, Raquel; Oliveira, Ana LeiteChronic wounds are one of the most frequent complications that are associated with diabetes mellitus. The overproduction of reactive oxygen species (ROS) is a key factor in the delayed healing of a chronic wound. In the present work, we develop a novel in situ-forming silk sericin-based hydrogel (SSH) that is produced by a simple methodology using horseradish peroxidase (HRP) crosslinking as an advanced dressing for wound healing. The antioxidant and angiogenic effects were assessed in vitro and in vivo after in situ application using an excisional wound-healing model in a genetically-induced diabetic db/db mice and though the chick embryo choriollantoic membrane (CAM) assay, respectively. Wounds in diabetic db/db mice that were treated with SSH closed with reduced granulation tissue, decreased wound edge distance, and wound thickness, when compared to Tegaderm, a dressing that is commonly used in the clinic. The hydrogel also promoted a deposition of collagen fibers with smaller diameter which may have had a boost effect in re-epithelialization. SSH treatment slightly induced two important endogenous antioxidant defenses, superoxide dismutase and catalase. A CAM assay made it possible to observe that SSH led to an increase in the number of newly formed vessels without inducing an inflammatory reaction. The present hydrogel may result in a multi-purpose technology with angiogenic, antioxidant, and anti-inflammatory properties, while advancing efficient and organized tissue regeneration.
- Microvascular, biochemical, and clinical impact of hyperbaric oxygen therapy in recalcitrant diabetic foot ulcersPublication . Martins-Mendes, Daniela; Costa, Raquel; Rodrigues, Ilda; Camacho, Óscar; Coelho, Pedro Barata; Paixão-Dias, Vítor; Luís, Carla; Pereira, Ana Cláudia; Fernandes, Rúben; Lima, Jorge; Soares, RaquelBackground: Diabetic foot ulcers (DFUs) are a serious complication of diabetes and are often difficult to treat. Hyperbaric oxygen therapy (HBOT) has been proposed as an adjunctive treatment to promote healing, but its long-term clinical and biological effects remain insufficiently characterized. This study aimed to evaluate the impact of HBOT on systemic biomarkers, local microvasculature, and clinical outcomes in patients with DFUs. Methods: In this non-randomized prospective study, 20 patients with ischemic DFUs were followed over a 36-month period. Fourteen received HBOT in addition to standard care, while six received standard care alone. Clinical outcomes—including DFU resolution, recurrence, lower extremity amputation (LEA), and mortality—were assessed alongside systemic inflammatory and angiogenic biomarkers and wound characteristics at baseline and at 3, 6, 12, and 36 months. CD31 immunostaining was performed on available tissue samples. Results: The two groups were comparable at baseline (mean age 62 ± 12 years; diabetes duration 18 ± 9 years). At 3 months, the HBOT group showed significant reductions in erythrocyte sedimentation rate and DFU size (p < 0.05), with downward trends observed in C-reactive protein (CRP), vascular endothelial growth factor (VEGF), and placental growth factor (PlGF), and an increase in stromal-derived factor-1 alpha (SDF1-?). No significant changes were observed in the control group. CD31+ microvessel density appeared to increase in HBOT-treated DFU tissue after one month, although the sample size was limited. Patients receiving HBOT had lower rates of LEA and mortality, improved wound healing, and sustained outcomes over three years. DFU recurrence rates were similar between groups. Conclusions: HBOT was associated with improved wound healing and favorable biomarker profiles in patients with treatment-resistant ischemic DFUs. While these findings are encouraging, the small sample size and non-randomized design limit their generalizability, highlighting the need for larger, controlled studies.
- Type 2 Diabetes mellitus alters the cargo of (poly)phenol metabolome and the oxidative status in circulating lipoproteinsPublication . Reis, Ana; Rocha, Sara; Dias, Irundika HK.; Costa, Raquel; Soares, Raquel; Sánchez-Quesada, José Luis; Perez, Antonio; Freitas, Victor deThe incidence of diabetes on the worldwide population has tripled in the past 5 decades. While drug-based therapies are valuable strategies to treat and ease the socio-economic burden of diabetes, nutritional strategies offer valuable alternatives to prevent and manage diabetes onset and contribute to the sustainability of health budgets. Whilst, intervention studies have shown that (poly)phenol-rich diets improve fasting glucose levels and other blood parameters, very little is known about the distribution of ingested polyphenols in circulation and the impact of diabetes on its cargo. In this study we investigate the impact of type 2 diabetes on the cargo of plasma (poly)phenols. Our results show that phenolic compounds are heterogeneously distributed in circulation though mainly transported by lipoprotein populations. We also found that diabetes has a marked effect on the phenolic content transported by VLDL resulting in the decrease in the content of flavonoids and consequently a decrease in the antioxidant capacity. In addition to the reduced bioavailability of (poly)phenol metabolites and increase of oxidative status in LDL and HDL populations in diabetes, cell-based assays show that sub-micromolar amounts of microbial (poly)phenol metabolites are able to counteract the pro-inflammatory status in glucose-challenged endothelial cells. Our findings highlight the relevance of triglyceride-rich lipoproteins in the transport and delivery of bioactive plant-based compounds to the endothelium in T2DM supporting the adoption of nutritional guidelines as an alternative strategy to drug-based therapeutic approaches.