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Background: Diabetic foot ulcers (DFU) pose a significant health risk in diabetic patients, with insufficient revascularization during wound healing being the primary cause. This study aimed to assess microvessel sprouting and wound healing capabilities using vascular endothelial growth factor (VEGF-A) and a modified fibroblast growth factor (FGF1). Methods: An ex vivo aortic ring rodent model and an in vivo wound healing model in diabetic mice were employed to evaluate the microvessel sprouting and wound healing capabilities of VEGF-A and a modified FGF1 both as monotherapies and in combination. Results: The combination of VEGF-A and FGF1 demonstrated increased vascular sprouting in the ex vivo mouse aortic ring model, and topical administration of a combination of VEGF-A and FGF1 mRNAs formulated in lipid nanoparticles (LNPs) in mouse skin wounds promoted faster wound closure and increased neovascularization seven days post-surgical wound creation. RNA-sequencing analysis of skin samples at day three post-wound creation revealed a strong transcriptional response of the wound healing process, with the combined treatment showing significant enrichment of genes linked to skin growth. Conclusion: f-LNPs encapsulating VEGF-A and FGF1 mRNAs present a promising approach to improving the scarring process in DFU., CC BY 4.0 DEED© 2024 by the authors.Correspondence Address: S. Tejedor; Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, 431 50, Sweden; email: sandra.tejedorgascon1@astrazeneca.com; K. Hansson; Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg, 431 50, Sweden; email: kenny.m.hansson@astrazeneca.comThis research was partially funded by grants from the Swedish Knowledge Foundation, grant number 20200014.

Small extracellular vesicles (sEV) derived from various cell sources have been demonstrated to enhance cardiac function in preclinical models of myocardial infarction (MI). The aim of this study was to compare different sources of sEV for cardiac repair and determine the most effective one, which nowadays remains limited. We comprehensively assessed the efficacy of sEV obtained from human primary bone marrow mesenchymal stromal cells (BM-MSC), human immortalized MSC (hTERT-MSC), human embryonic stem cells (ESC), ESC-derived cardiac progenitor cells (CPC), human ESC-derived cardiomyocytes (CM), and human primary ventricular cardiac fibroblasts (VCF), in in vitro models of cardiac repair. ESC-derived sEV (ESC-sEV) exhibited the best pro-angiogenic and anti-fibrotic effects in vitro. Then, we evaluated the functionality of the sEV with the most promising performances in vitro, in a murine model of MI-reperfusion injury (IRI) and analysed their RNA and protein compositions. In vivo, ESC-sEV provided the most favourable outcome after MI by reducing adverse cardiac remodelling through down-regulating fibrosis and increasing angiogenesis. Furthermore, transcriptomic, and proteomic characterizations of sEV derived from hTERT-MSC, ESC, and CPC revealed factors in ESC-sEV that potentially drove the observed functions. In conclusion, ESC-sEV holds great promise as a cell-free treatment for promoting cardiac repair following MI., CC BY 4.0 DEED© 2024 AstraZeneca R&D and The Authors. Journal of Extracellular Vesicles published by Wiley Periodicals LLC on behalf of International Society for Extracellular Vesicles.Correspondence Address: H. González-King; Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Mölndal, Sweden; email: hernan.gonzalez-king@astrazeneca.com; K. Jennbacken; Research and Early Development, Cardiovascular, Renal and Metabolism, BioPharmaceuticals R&D, AstraZeneca, Mölndal, Sweden; email: Karin.jennbacken@astrazeneca.comFunding information: Högskolan i Skövde, Grant/Award Number: grant# 20200014The authors of this manuscript acknowledge AstraZeneca early CVRM Cardiovascular for their resource management, to John Liddle and Stefan Geschwindner from AstraZeneca postdoc committee for their advice, to AstraZeneca Animal Sciences & Technologies staff for their in vivo support, to Märta Jansson for performing the flow cytometric characterization of cardiac progenitor cells and to Elisa Lázaro and Olga Shatnyeva from the exosome team in AstraZeneca for input and facilitating a smooth introduction to AstraZeneca’s exosome research, to the National Genomics Infrastructure in Stockholm funded by Science for Life Laboratory, the Knut and Alice Wallenberg Foundation and the Swedish Research Council, and SNIC/Uppsala Multidisciplinary Center for Advanced Computational Science for assistance with massively parallel sequencing and access to the UPPMAX computational infrastructure. We also thank M. Soriano at the core facility of electron microscopy-Centro de Investigación Príncipe Felipe. This manuscript was edited at Life Science Editors. This work was supported by the University of Skövde under grants from the Swedish Knowledge foundation [grant # 20200014].

Transplantation of pancreatic islets is one approach for treatment of diabetes, however, hampered by the low availability of viable islets. Islet isolation leads to disruption of the environment surrounding the endocrine cells, which contributes to eventual cell death. The reestablishment of this environment is vital, why we herein investigated the possibility of using recombinant spider silk to support islets in vitro after isolation. The spider silk protein 4RepCT was formulated into three different formats; 2D-film, fiber mesh and 3D-foam, in order to provide a matrix that can give the islets physical support in vitro. Moreover, cell-binding motifs from laminin were incorporated into the silk protein in order to create matrices that mimic the natural cell environment. Pancreatic mouse islets were thoroughly analyzed for adherence, necrosis and function after in vitro maintenance on the silk matrices. To investigate their suitability for transplantation, we utilized an eye model which allows in vivo imaging of engraftment. Interestingly, islets that had been maintained on silk foam during in vitro culture showed improved revascularization. This coincided with the observation of preserved islet architecture with endothelial cells present after in vitro culture on silk foam. Selected matrices were further evaluated for long-term preservation of human islets. Matrices with the cell-binding motif RGD improved human islet maintenance (from 36% to 79%) with preserved islets architecture and function for over 3 months in vitro. The islets established cell-matrix contacts and formed vessel-like structures along the silk. Moreover, RGD matrices promoted formation of new, insulin-positive islet-like clusters that were connected to the original islets via endothelial cells. On silk matrices with islets from younger donors (<35 year), the amount of newly formed islet-like clusters found after 1 month in culture were almost double compared to the initial number of islets ad