Influence of different ECM-like hydrogels on neurite outgrowth induced by adipose tissue-derived stem cells

Mesenchymal stem cells (MSCs) have been proposed for spinal cord injury (SCI) applications due to their capacity to secrete growth factors and vesicles-secretome-that impacts important phenomena in SCI regeneration. To improve MSC survival into SCI sites, hydrogels have been used as transplantation vehicles. Herein, we hypothesized if different hydrogels could interact differently with adipose tissue-derived MSCs (ASCs). The efficacy of three natural hydrogels, gellan gum (functionalized with a fibronectin peptide), collagen, and a hydrogel rich in laminin epitopes (NVR-gel) in promoting neuritogenesis (alone and cocultured with ASCs), was evaluated in the present study. Their impact on ASC survival, metabolic activity, and gene expression was also evaluated. Our results indicated that all hydrogels supported ASC survival and viability, being this more evident for the functionalized GG hydrogels. Moreover, the presence of different ECM-derived biological cues within the hydrogels appears to differently affect the mRNA levels of growth factors involved in neuronal survival, differentiation, and axonal outgrowth. All the hydrogel-based systems supported axonal growth mediated by ASCs, but this effect was more robust in functionalized GG. The data herein presented highlights the importance of biological cues within hydrogel-based biomaterials as possible modulators of ASC secretome and its effects for SCI applications.This study is funded by Prémios Santa Casa Neurociências—Prize Melo e Castro for Spinal Cord Injury Research. This is also partially funded by EU-FP7-Health-2011-Collaborative Project 278612, Biohybrid—Templates for peripheral nerve regeneration, and Portuguese Foundation for Science and Technology (IF Development Grant to A. J. Salgado; postdoctoral fellowship to N. A. Silva—SFRH/BPD/97701/2013; PhD fellowships of R. C. Assunção-Silva and E. D. Gomes—PDE/BDE/113596/2015 and SFRH/BD/103075/2014, resp.). This article is a result of the project (NORTE-01-0145-FEDER-000013) supported by the Norte Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, through the European Regional Development Fund (ERDF); Cofinanciado pelo ProgramaOperacional Regional do Norte(ON.2 SR&TD Integrated Program—NORTE-07-0124-FEDER-000021), ao abrigo do Quadro de Referência Estratégico Nacional (QREN), através do Fundo Europeude Desenvolvimento Regional (FEDER); Projeto Estratégico—LA 26–2011-2012 and Projeto Estratégico—LA 26–2013-2014 cofinanciado por fundos nacionais, através da Fundação para a Ciência e a Tecnologia (PEst-C/SAU/LA0026/2011; PEst-C/SAU/LA0026/2013), e pelo Fundo Europeu de Desenvolvimento Regional (FEDER), através do COMPETE (FCOMP-01-0124-FEDER-022724; FCOMP-01-0124-FEDER-037298). The authors would like to thank Professor Jeffrey Gimble at the Tulane University Center for Stem Cell Research and Regenerative Medicine and LaCell LLC (New Orleans, Louisiana, USA) for kindly providing the ASCs used in this study.info:eu-repo/semantics/publishedVersio

Rheological properties of magnetic biogels

We report an experimental and theoretical study of the rheological properties of magnetic biogels consisting of fibrin polymer networks with embedded magnetite nanoparticles, swollen by aqueous solutions. We studied two types of magnetic biogels, differenced by the presence or absence of an applied magnetic field during the initial steps of cross-linking. The experiments demonstrated very strong dependence of the elastic modulus of the magnetic biogels on the concentration of the magnetic particles. We finally developed some theoretical models that explain the observed strong concentration effects.This study was supported by projects FIS2013-41821-R (Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, MINECO, Spain, co-funded by ERDF, European Union) and FIS2017-85954-R (Ministerio de Economía, Industria y Competitividad, MINECO, andAgencia Estatal de Investigación, AEI, Spain, co-funded by Fondo Europeo de Desarrollo Regional, FEDER, European Union). A.Z. is grateful to the program of the Ministry of Education and Science of the Russian Federation, projects 02.A03.21.0006, 3.1438.2017/4.6, and 3.5214.2017/6.7, as well as to the Russian Fund of Basic Researches, project 18-08-00178