title: Pharmacologically active microcarriers delivering BDNF within a hydrogel: Novel strategy for human bone marrow-derived stem cells neural/neuronal differentiation guidance and therapeutic secretome enhancement.
abstract: Stem cells combined with biodegradable injectable scaffolds releasing growth factors hold great promises in regenerative medicine, particularly in the treatment of neurological disorders. We here integrated human marrow-isolated adult multilineage-inducible (MIAMI) stem cells and pharmacologically active microcarriers (PAMs) into an injectable non-toxic silanized-hydroxypropyl methylcellulose (Si-HPMC) hydrogel. The goal is to obtain an injectable non-toxic cell and growth factor delivery device. It should direct the survival and/or neuronal differentiation of the grafted cells, to safely transplant them in the central nervous system, and enhance their tissue repair properties. A model protein was used to optimize the nanoprecipitation conditions of the neuroprotective brain-derived neurotrophic factor (BDNF). BDNF nanoprecipitate was encapsulated in fibronectin-coated (FN) PAMs and the in vitro release profile evaluated. It showed a prolonged, bi-phasic, release of bioactive BDNF, without burst effect. We demonstrated that PAMs and the Si-HPMC hydrogel increased the expression of neural/neuronal differentiation markers of MIAMI cells after 1week. Moreover, the 3D environment (PAMs or hydrogel) increased MIAMI cells secretion of growth factors (b-NGF, SCF, HGF, LIF, PlGF-1, SDF-1α, VEGF-A & D) and chemokines (MIP-1α & β, RANTES, IL-8). These results show that PAMs delivering BDNF combined with Si-HPMC hydrogel represent a useful novel local delivery tool in the context of neurological disorders. It not only provides neuroprotective BDNF but also bone marrow-derived stem cells that benefit from that environment by displaying neural commitment and an improved neuroprotective/reparative secretome. It provides preliminary evidence of a promising pro-angiogenic, neuroprotective and axonal growth-promoting device for the nervous system.
  
  
  
  Combinatorial tissue engineering strategies for the central nervous system are scarce. We developed and characterized a novel injectable non-toxic stem cell and protein delivery system providing regenerative cues for central nervous system disorders. BDNF, a neurotrophic factor with a wide-range effect, was nanoprecipitated to maintain its structure and released in a sustained manner from novel polymeric microcarriers. The combinatorial 3D support, provided by fibronectin-microcarriers and the hydrogel, to the mesenchymal stem cells guided the cells towards a neuronal differentiation and enhanced their tissue repair properties by promoting growth factors and cytokine secretion. The long-term release of physiological doses of bioactive BDNF, combined to the enhanced secretion of tissue repair factors from the stem cells, constitute a promising therapeutic approach.
authors.affiliation: INSERM U 1066, 'Micro et Nanomédecines biomimétiques-MINT', Angers, France; Université Angers, UMR-S1066, Angers, France.
authors.forename: Saikrishna
authors.initials: S
authors.lastname: Kandalam
authors.affiliation: INSERM U 1066, 'Micro et Nanomédecines biomimétiques-MINT', Angers, France; Université Angers, UMR-S1066, Angers, France.
authors.forename: Laurence
authors.initials: L
authors.lastname: Sindji
authors.affiliation: GRECC and Research Service, Veterans Affairs Medical Center, Miami, FL, USA; Department of Orthopaedics, University of Miami Miller School of Medicine, FL, USA; Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA.
authors.forename: Gaëtan J-R
authors.initials: GJ
authors.lastname: Delcroix
authors.affiliation: INSERM U 1066, 'Micro et Nanomédecines biomimétiques-MINT', Angers, France; Université Angers, UMR-S1066, Angers, France.
authors.forename: Fabien
authors.initials: F
authors.lastname: Violet
authors.affiliation: Artificial Biopolymers Department, Institut des Biomolecules Max Mousseron (IBMM) UMR5247, CNRS, University of Montpellier, ENSCM, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Garric
authors.affiliation: INSERM U 1066, 'Micro et Nanomédecines biomimétiques-MINT', Angers, France; Université Angers, UMR-S1066, Angers, France.
authors.forename: Emilie M
authors.initials: EM
authors.lastname: André
authors.affiliation: GRECC and Research Service, Veterans Affairs Medical Center, Miami, FL, USA; Department of Orthopaedics, University of Miami Miller School of Medicine, FL, USA; Interdisciplinary Stem Cell Institute, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Biochemistry & Molecular Biology, University of Miami Miller School of Medicine, FL, USA; Geriatrics Institute, University of Miami Miller School of Medicine, FL, USA.
authors.forename: Paul C
authors.initials: PC
authors.lastname: Schiller
authors.affiliation: INSERM U 1066, 'Micro et Nanomédecines biomimétiques-MINT', Angers, France; Université Angers, UMR-S1066, Angers, France.
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Venier-Julienne
authors.affiliation: Louvain Drug Research Institute, Advanced Drug Delivery and Biomaterials, Université Catholique de Louvain, 1200 Bruxelles, Belgium; Institute of Condensed Matter and Nanosciences, Université Catholique de Louvain, 1048 Louvain-la-Neuve, Belgium.
authors.forename: Anne
authors.initials: A
authors.lastname: des Rieux
authors.affiliation: INSERMU791, Laboratory for Osteo-Articular and Dental Tissue Engineering LIOAD, groupe STEP, 44042 Nantes, France; University of Nantes, UFR Odontologie, 44042 Nantes, France; CHU Nantes, PHU 4 OTONN, 44042 Nantes, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Guicheux
authors.affiliation: INSERM U 1066, 'Micro et Nanomédecines biomimétiques-MINT', Angers, France; Université Angers, UMR-S1066, Angers, France. Electronic address: claudia.montero-menei@univ-angers.fr.
authors.forename: Claudia N
authors.initials: CN
authors.lastname: Montero-Menei
mesh_terms: D000368:Aged; D001672:Biocompatible Materials / Q000494:pharmacology; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D048430:Cell Shape / Q000187:drug effects; D011232:Chemical Precipitation; D065546:Drug Liberation; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D065347:Hypromellose Derivatives / Q000737:chemistry; D008297:Male; D059630:Mesenchymal Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D008863:Microspheres; D053758:Nanoparticles / Q000737:chemistry; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D020543:Proteome / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012212:Rheology; D012821:Silanes / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D019208:Brain-Derived Neurotrophic Factor; D020543:Proteome; D012333:RNA, Messenger; D012821:Silanes; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D065347:Hypromellose Derivatives
keywords: BDNF drug delivery; Mesenchymal stem cells; Microspheres; Neural repair; Si-HPMC hydrogel