title: Electrically driven intracellular and extracellular nanomanipulators evoke neurogenic/cardiomyogenic differentiation in human mesenchymal stem cells.
abstract: Nanomechanical intervention through electroactuation is an effective strategy to guide stem cell differentiation for tissue engineering and regenerative medicine. In the present study, we elucidate that physical forces exerted by electroactuated gold nanoparticles (GNPs) have a strong influence in regulating the lineage commitment of human mesenchymal stem cells (hMSCs). A novel platform that combines intracellular and extracellular GNPs as nano-manipulators was designed to trigger neurogenic/cardiomyogenic differentiation in hMSCs, in electric field stimulated culture condition. In order to mimic the native microenvironment of nerve and cardiac tissues, hMSCs were treated with physiologically relevant direct current electric field (DC EF) or pulsed electric field (PEF) stimuli, respectively. When exposed to regular intermittent cycles of DC EF stimuli, majority of the GNP actuated hMSCs acquired longer filopodial extensions with multiple branch-points possessing neural-like architecture. Such morphological changes were consistent with higher mRNA expression level for neural-specific markers. On the other hand, PEF elicited cardiomyogenic differentiation, which is commensurate with the tube-like morphological alterations along with the upregulation of cardiac specific markers. The observed effect was significantly promoted even by intracellular actuation and was found to be substrate independent. Further, we have substantiated the participation of oxidative signaling, G0/G1 cell cycle arrest and intracellular calcium [Ca(2+)]i elevation as the key upstream regulators dictating GNP assisted hMSC differentiation. Thus, by adopting dual stimulation protocols, we could successfully divert the DC EF exposed cells to differentiate predominantly into neural-like cells and PEF treated cells into cardiomyogenic-like cells, via nanoactuation of GNPs. Such a novel multifaceted approach can be exploited to combat tissue loss following brain injury or heart failure.
authors.affiliation: Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore, India; Centre for Nanoscience & Engineering, Indian Institute of Science, Bangalore, India, 560012.
authors.forename: Greeshma
authors.initials: G
authors.lastname: Thrivikraman
authors.affiliation: Department of Chemical Engineering, Indian Institute of Science, Bangalore, India, 560012.
authors.forename: Giridhar
authors.initials: G
authors.lastname: Madras
authors.affiliation: Laboratory for Biomaterials, Materials Research Centre, Indian Institute of Science, Bangalore, India. Electronic address: bikram@mrc.iisc.ernet.in.
authors.forename: Bikramjit
authors.initials: B
authors.lastname: Basu
mesh_terms: D015415:Biomarkers; D020013:Calcium Signaling / Q000528:radiation effects; D002453:Cell Cycle / Q000528:radiation effects; D019070:Cell Lineage / Q000528:radiation effects; D048430:Cell Shape; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000528:radiation effects; D004558:Electric Stimulation; D004574:Electromagnetic Fields; D017979:Gold Colloid / Q000528:radiation effects*; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000528:radiation effects*; D055617:Micro-Electrical-Mechanical Systems; D024510:Muscle Development / Q000528:radiation effects*; D032383:Myocytes, Cardiac / Q000166:cytology; D053761:Nanocomposites / Q000528:radiation effects; D053758:Nanoparticles / Q000528:radiation effects*; D055495:Neurogenesis / Q000528:radiation effects*; D009474:Neurons / Q000166:cytology; D010812:Physical Stimulation; D013499:Surface Properties; D015854:Up-Regulation / Q000528:radiation effects
chemical_list: D015415:Biomarkers; D020099:Coated Materials, Biocompatible; D017979:Gold Colloid
keywords: Cardiomyogenic differentiation; Electroactuation; Gold nanoparticles (GNPs); Neural architecture; Stimulation protocols