The beneficial effect of encapsulated human adipose-derived stem cells in alginate hydrogel on neural differentiation Zahra Khosravizadeh, Shahnaz Razavi, Hamid Bahramian, Mohammad Kazemi Department of Anatomical Sciences and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, 81744-176, Iran Received 28 May 2013; revised 7 September 2013; accepted 22 September 2013 Published online 21 October 2013 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jbm.b.33055 Abstract: Tissue engineering employs combination of bioma- terials and cell therapy to develop new therapeutic strategies for neurodegenerative diseases, spinal cord, and traumatic brain injuries. Alginate is a biocompatible hydrogel, which has been used broadly to encapsulate many types of cells. Human adipose-derived stem cells (hADSCs) have appropri- ate property to differentiate into neuron-like cells. Therefore, the aim of this study was to evaluate the effect of alginate hydrogel on the viability and neural differentiation potential of induced hADSCs. After neural induction of isolated hADSCs and encapsulated in alginate hydrogel, the cell via- bility using MTT assay and their neural differentiation poten- tial by immunocytochemical and real time RT-PCR analysis for neural markers (Nestin, GFAP, and MAP2) were evaluated. Expression of Nestin, GFAP, and MAP2 markers was signifi- cantly increased compare to monolayer induced cells (p < 0.001), but we did not found any significant effect on via- bility of induced cells relative to monolayer induced cells. Although neural differentiation of encapsulated cells was increased relative to monolayer induced cells, the viability of these cells was not significantly different in alginate hydro- gel as compared with monolayer induced cells. VC 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 102B: 749–755, 2014. Key Words: human adipose-derived stem cells, alginate hydrogel, proliferation, neural differentiation, tissue engineering How to cite this article: Khosravizadeh Z, Razavi S, Bahramian H, Kazemi M. 2014. The beneficial effect of encapsulated human adipose-derived stem cells in alginate hydrogel on neural differentiation. J Biomed Mater Res Part B 2014:102B:749–755. INTRODUCTION The central nervous system has been universally thought to be infirm of self-repair after injury because mature neurons cannot regenerate themselves, also neural stem cells (NSCs) have limited to produce new functional neurons. 1 Neural tissue engineering focuses on development of biomaterials that could support regeneration of neurons after trauma or injuries caused by degenerative diseases. Tissue engineering usually involves culture of cells on a scaffold similar to the natural extracellular matrix (ECM) of tissues. 2 Hydrogels are attractive scaffolds for tissue engineering because of their porous structure, tissue-like mechanical properties, and attachment potential to growth-promoting molecules when are swollen with water. 3–5 Due to the loss of the nervous system’s ECM after injury, usage of hydrogels as scaffold to replace ECM and support axonal growth is the most important strategies of neural tissue engineering. Alginate is a water-soluble linear polymer that is com- posed of D-mannuronic acid (M) and L-guluronic acid (G) monomers. Because of their gelling ability, stabilizing prop- erties, and high-viscosity in aqueous solutions, alginate is widely used in the food, cosmetics, and pharmaceutical industries. 6,7 Alginate hydrogels are prepared when divalent cation (e.g., calcium) interact with G-sequences of sodium alginate solution. 8,9 Its useful properties such as hydrophi- licity and due to protect the enclosed cellular tissue from the host’s immune response, have lower immunogenicity, also alginate is abundant, cheap, and non-toxic. 10–12 Because of its biocompatibility, cells do not damage during the gel- ling process and ionically cross linked, therefore alginate is widely used for drug delivery, cell encapsulation, and tissue regeneration. 13–17 Currently, stem and progenitor cells were isolated from adult tissues such as bone marrow, skin, muscle, and fat. 18 Bone marrow has more investigated for clinical applications such as neural tissue 19–21 but adipose tissue might have advantages compare to bone marrow such as: least morbidity on harvesting; frequency of its stem cell number, which is significantly higher compared to bone marrow; and their pro- liferation rates are higher than bone marrow stem cells, also human adipose-derived stem cells (hADSCs) can be obtained by less invasive method. 22–26 Cells isolated from adipose- derived stem cells (ADSCs) are able to self-renew and differ- entiate along several mesenchymal tissue lineages. 27,28 They can be harvested in significant numbers and show constant stable growth and proliferation kinetics in culture. 27 Human ADSCs express neurotrophic factors and cells harvested from the superficial abdominal fat promote Correspondence to: S. Razavi (e-mail: razavi@med.mui.ac.ir) VC 2013 WILEY PERIODICALS, INC. 749