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The administration of extracellular vesicles (EV) from mesenchymal stromal cells (MSC) is a promising cell-free nanotherapy for tissue repair after myocardial infarction (MI). However, the optimal EV delivery strategy remains undetermined. Here, we designed a novel MSC-EV delivery, using 3D scaffolds engineered from decellularised cardiac tissue as a cell-free product for cardiac repair. EV from porcine cardiac adipose tissue-derived MSC (cATMSC) were purified by size exclusion chromatography (SEC), functionally analysed and loaded to scaffolds. cATMSC-EV markedly reduced polyclonal proliferation and pro-inflammatory cytokines production (IFNγ, TNFα, IL12p40) of allogeneic PBMC. Moreover, cATMSC-EV recruited outgrowth endothelial cells (OEC) and allogeneic MSC, and promoted angiogenesis. Fluorescently labelled cATMSC-EV were mixed with peptide hydrogel, and were successfully retained in decellularised scaffolds. Then, cATMSC-EV-embedded pericardial scaffolds were administered in vivo over the ischemic myocardium in a pig model of MI. Six days from implantation, the engineered scaffold efficiently integrated into the post-infarcted myocardium. cATMSC-EV were detected within the construct and MI core, and promoted an increase in vascular density and reduction in macrophage and T cell infiltration within the damaged myocardium. The confined administration of multifunctional MSC-EV within an engineered pericardial scaffold ensures local EV dosage and release, and generates a vascularised bioactive niche for cell recruitment, engraftment and modulation of short-term post-ischemic inflammation., Graphical abstract Image 1, Highlights • A bioactive engineered scaffold can locally deliver EV to the infarcted myocardium. • Porcine cATMSC-EV promote endothelial cell recruitment and in vivo vascularization. • Porcine cATMSC-EV reduce inflammation, and macrophage and T cell infiltration.

Recent studies have shown that retinal neurodegeneration may precede visible vascular changes in diabetic retinopathy (DR). In addition, the relationship of choroidal thickness (CT) with DR stage is not well defined. To assess the inner retinal and choroidal structural changes in type 1 diabetic subjects (T1D), a cross-sectional study was conducted in 242 T1D patients and in 69 age-matched, non-diabetic individuals. The nasal retinal nerve fibre layer (RNFL) thickness was lower in T1D patients without DR (p &lt, 0.001), with mild DR (p &lt, 0.001), and with advanced DR (p &lt, 0.001) compared to control subjects. The ganglion cell layer (GCL) thickness was lower in T1D patients with advanced DR compared to those with mild DR (p = 0.003) and without DR (p &lt, 0.001) and compared to the control subjects (p &lt, 0.001). T1D subjects with no DR and mild DR had higher CT than the control subjects, but the CT in T1D patients with advanced DR was lower (p = 0.038) than that in T1D subjects with mild DR and was not significantly different from that of the control subjects. In conclusion, T1D subjects showed a significant thinning of the nasal RNFL in the early stages of the disease, even before any vascular changes in the retina. A decrease in the GCL thickness during advanced DR stages was observed. Choroidal thickness was higher in T1D subjects without DR and in early DR stages but decreased in advanced stages.

A preclinical model of glioblastoma (GB) bystander cell therapy using human adipose mesenchymal stromal cells (hAMSCs) is used to address the issues of cell availability, quality, and feasibility of tumor cure. We show that a fast proliferating variety of hAMSCs expressing thymidine kinase (TK) has therapeutic capacity equivalent to that of TK-expressing hAMSCs and can be used in a multiple-inoculation procedure to reduce GB tumors to a chronically inhibited state. We also show that up to 25% of unmodified hAMSCs can be tolerated in the therapeutic procedure without reducing efficacy. Moreover, mimicking a clinical situation, tumor debulking previous to cell therapy inhibits GB tumor growth. To understand these striking results at a cellular level, we used a bioluminescence imaging strategy and showed that tumor-implanted therapeutic cells do not proliferate, are unaffected by GCV, and spontaneously decrease to a stable level. Moreover, using the CLARITY procedure for tridimensional visualization of fluorescent cells in transparent brains, we find therapeutic cells forming vascular-like structures that often associate with tumor cells. In vitro experiments show that therapeutic cells exposed to GCV produce cytotoxic extracellular vesicles and suggest that a similar mechanism may be responsible for the in vivo therapeutic effectiveness of TK-expressing hAMSCs. © 2018 The Author(s), This work was funded by the Spanish Ministry of Science and Innovation (MICINN) (grant SAF2015-64927-C2-1-R), CIBER-BBN, CIBER Cardiovascular (grant CB16/11/00403), Instituto de Salud Carlos III, Red Temática de Investigación Cooperativa TerCel, and the Spanish Ministry of Economy and Competitiveness (MINECO) (grant BIO2015-66266-R). The authors specially thank Dr. Josep Roca from Delfos hospital (Dr. Roca i Noguera aesthetic surgery team) for the kind donation of liposuction for hAMSCs preparation, and to the services of cell culture (Catalonian Institute for Advanced Chemistry-Spanish National Research Council [IQAC-CISC]), animal care (IQAC-CSIC), cell sorting (Scientific and Technological Centers [CCiT]-University of Barcelona), confocal microscopy (CCiT-University of Barcelona), and Central Services for Research Support (SCAI) at the University of Málaga for their technician and specialized support.