labeling-extracellular-vesicles-for-monitoring-migration-uptake

Labeling of Extracellular Vesicles for Monitoring Migration and Uptake in Cartilage Explants

Extracellular vesicles (EVs) are used in different studies to prove their potential as a cell-free treatment due to their cargo derived from their ...

platelet-derived-extracellular-vesicle-functionalization-ti

Platelet-Derived Extracellular Vesicle Functionalization of Ti Implants

Extracellular Vesicles (EVs) are biological nanovesicles that play a key role in cell communication. Their content includes active biomolecules such as ...

Health Research Institute of the Balearic Islands (IdISBa)

Fundació Banc de Sang i Teixits de les Illes Balears (FBSTIB)

University of the Balearic Islands

It is widely agreed that the best source of nutrition for the newborn is the milk of their own mothers. In those cases where it is not available, especially in very premature and/or very low birth weight infants, as well as other sick newborns, the preferred choice before formula is the human milk provided by selected donors. This indication is supported by the highest international bodies dedicated to the health of the child population, including the World Health Organisation as well as the main national and international scientific societies in the field of Paediatrics. Milk banks are health institutions responsible for the collection, processing and distribution of donated human milk. Currently, there are 14 human milk banks operating in Spain, grouped in the Spanish Association of Human Milk Banks, created in September 2008. In order to homogenise the criteria and to unify the working methods of the different milk banks, the Spanish Association of Human Milk Banks has developed standards to harmonise the protocols, and to serve as a guide for the start-up of new milk banks in the Spanish territory. These standards, set out in the present article, range from the donor selection and the evaluation process to the collection, processing, storage, and distribution of donor human milk.

[Recommendations for the creation and operation of maternal milk banks in Spain].

Osteoinductive capacity of demineralized bone matrix (DBM) is sometimes insufficient or shows high variability between different batches of DBM. Here, we tried to improve its osteoinductive activity by alkali-urea or trypsin treatment but this strategy was unsuccessful. Then, we tested the enrichment of DBM with a bone protein extract (BPE) containing osteogenic growth factors comparing two sources: cortical bone powder and DBM. The osteoinductive capacity (alkaline phosphatase activity) of the obtained BPEs was evaluated in vitro in C2C12 cells. Specific protein levels present in the different BPE was determined by enzyme-linked immunosorbent assay or by a multiplex assay. BPE from cortical bone powder showed a lack of osteoinductive effect, in agreement with the low content on osteoinductive factors. In contrast, BPE from DBM showed osteoinductive activity but also high variability among donors. Thus, we decided to enrich DBM with BPE obtained from a pool of DBM from different donors. Following this strategy, we achieved increased osteoinductive activity and lower variability among donors. In conclusion, the use of a BPE obtained from a pool of demineralized bone to enrich DBM could be used to increase its osteoinductive effect and normalize the differences between donors.

Enhanced osteoinductive capacity and decreased variability by enrichment of demineralized bone matrix with a bone protein extract.

The aim of this review is to evaluate changes in protein parameters in the second year postpartum. There is considerable agreement among authors about the declining trend of human milk protein concentrations, but most research on protein content in breast milk focuses on the first year of life and comes from developed countries. Whereas this is the case for exclusive breastfeeding or for breastfeeding into the first year of life, the opposite applies to weaning or extended breastfeeding. This review is predominantly based on observational epidemiological evidence and on comparative research linking breast milk composition with cutting down on breastfeeding. Studies dating back several decades have shown an increase in the proportion of immunoglobulins, lactoferrin, and serum albumin during weaning. According to the limited data available, it seems likely that the regulation of milk protein composition during involution can be ascribed to alterations in tight junctions. In studies on humans and other mammalian species, offspring suckle more from mothers that produce more dilute milk and the increase in milk protein concentration is positively correlated to a decrease in suckling frequency during weaning. High milk protein contents were first reported in nonindustrial communities where breastfeeding is sustained the longest, but recent papers from urbanized communities have taken credit for rediscovering the increase in protein content of human milk that becomes evident with prolonged breastfeeding. This review presents an overview of the changes in breast milk protein parameters in the second year postpartum to enable milk banks' practitioners to make informed nutritional decisions on preterm infants.

Variation in the Protein Composition of Human Milk during Extended Lactation: A Narrative Review.

Progress in transplantation means the process of procuring both human organ and tissues has become a daily challenge. Considering that tissues are usually procured from organ donors who have suffered brain death or after controlled cardiac death, the tissue procurement is done mainly in major hospitals. With the aim of highlighting the potential role of regional hospitals in tissue donation, a prospective descriptive study was carried out of all the patients who died at the Regional Hospital of Inca in Mallorca (Spain) from January 2013 to August 2018. To ensure an early detection of all possible tissue donors, the hospital has implemented a computerized alert system that is activated immediately after a patient dies. This strategy has proven to be very useful as in the analyzed period, the hospital had an average of 280 donors per million population, which is one of the highest rates of cornea donation among the Spanish hospitals. Our data and experience show the important role of regional hospitals in tissue donation and the value of implementing screening programs and early selection of potential tissue donors.

Tissue Donors in Regional Hospitals: A Reality.

The demineralized bone matrix (DBM) is the most widely used bone allograft, which is obtained by removing the mineral component of bone, leading to exposure of the proteins responsible for osteoinduction. For clinical use, DBM shall be formulated with a carrier that provides consistency and improves its osteoinduction. In this study, three DBM formulations with glycerol (Gly), hyaluronic acid (HA), and gelatin methacryloyl (GelMA) were evaluated measuring their physicochemical properties (microstructure, compressive strength, and serum cohesivity) and their osteoinductive capacity both in vitro using C2C12 cells and umbilical cord human mesenchymal stem cells and in vivo in an ectopic bone formation model in athymic mice. To assess the effectiveness of DBM in vitro in inducing the differentiation into osteoblasts, alkaline phosphatase (ALP) activity was assessed in combination with a cytotoxicity assay. In vivo, new bone formation was assessed by histological and radiological analysis. In the compression and in the serum cohesive assays, the GelMA DBM formulation showed its superiority over the other formulations. In addition, GelMA showed a more compact structure analysed by scanning electron microscopy. Higher cell toxicity was observed on Gly formulations in vitro, whereas GelMa and HA showed very low toxicity. All formulations significantly improved ALP activity compared with control. In the in vivo studies, GelMA showed the greatest osteoinductive potential with a higher percentage of new bone and bone marrow formation. Our results suggest GelMA is useful as a carrier for DBM designed to promote the formation of the new bone.

Improved physical and osteoinductive properties of demineralized bone matrix by gelatin methacryloyl formulation.

Extracellular vesicles (EVs) have been recently identified as vital components of cell-based therapies based on the observation that conditioned media from cultured stromal cells reproduce some of the beneficial effects of intact cells. In order to obtain clinically active EVs derived from Mesenchymal Stromal Cells (MSCs) different procedures have been reported in the literature. Usually, non-confluent cells are incubated with culture medium for 48 h either with EV-depleted Fetal Bovine Serum (FBS) or without FBS. Our aim was to compare the effects of EVs isolated by ultracentrifugation from human umbilical cord MSC conditioned media obtained using these two conditions: with EV-depleted FBS (UC) or without FBS (UC) on the mRNA expression levels of extracellular matrix related genes using the mouse chondrogenic cell line ATDC-5. We observed a deleterious effect on chondrogenic cells treated with UC, showing higher mRNA expression levels of different metalloproteinases and decorin () and lower collagen ( and ) and aggrecan () mRNA levels. To elucidate whether this deleterious effect was induced by the EVs or by any proteins co-purified in the EV pellet, we used size exclusion chromatography (SEC) to further purify the EV pellet, obtaining an EV enriched fraction (EV or EV) and a protein enriched fraction (Prot or Prot). Our results pointed that the negative effect on the chondrogenic cell line was due to the contaminant proteins coisolated with the EVs by ultracentrifugation and not from the EVs themselves. Thus, these results highlight the importance of working with well purified EV preparations to specifically achieve their therapeutic effect.

Purity Determines the Effect of Extracellular Vesicles Derived from Mesenchymal Stromal Cells.

Platelet concentrates, like platelet-rich plasma (PRP) and platelet lysate (PL), are widely used in regenerative medicine, especially in bone regeneration. However, the lack of standard procedures and controls leads to high variability in the obtained results, limiting their regular clinical use. Here, we propose the use of platelet-derived extracellular vesicles (EVs) as an off-the-shelf alternative for PRP and PL for bone regeneration. In this article, we evaluate the effect of PL-derived EVs on the biocompatibility and differentiation of mesenchymal stromal cells (MSCs).

ArticleTotal : 2	Year
Publication title	2021
Publication title	2021

Article	Year
[Recommendations for the creation and operation of maternal milk banks in Spain]. Anales de pediatria\| PubMed ID: 29496426	2018
Enhanced osteoinductive capacity and decreased variability by enrichment of demineralized bone matrix with a bone protein extract. Journal of materials science. Materials in medicine\| PubMed ID: 29956013	2018
Variation in the Protein Composition of Human Milk during Extended Lactation: A Narrative Review. Nutrients\| PubMed ID: 30127252	2018
Tissue Donors in Regional Hospitals: A Reality. Transplantation proceedings\| PubMed ID: 31627921	2019
Improved physical and osteoinductive properties of demineralized bone matrix by gelatin methacryloyl formulation. Journal of tissue engineering and regenerative medicine\| PubMed ID: 32011080	2020
Purity Determines the Effect of Extracellular Vesicles Derived from Mesenchymal Stromal Cells. Cells\| PubMed ID: 32059497	2020
Platelet-derived extracellular vesicles promote osteoinduction of mesenchymal stromal cells. Bone & joint research\| PubMed ID: 33101656	2020

Javier Calvo

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