en Tissue Engineering and Cell Biology Tissue Engineering and Cell Biology مقاله کامل Full Length/Original Article <strong>Background: </strong>Solvent casting/particulate leaching is one of the most conventional methods for fabricating polymer/ceramic composite scaffolds. In this method, the solvent generally affects resulting scaffold properties, including porosity and degradation rate. <strong>Methods:</strong> Herein, composite scaffolds of PLGA (poly(lactide-co-glycolide))/ nano-hydroxyapatite (nHA) with different percentages of nHA (25, 35, and 45 wt. %) were prepared by the solvent casting/particle leaching combined with freeze drying. The effects of two different solvents, 1,4-dioxane (DIO) and N-methyl-2-pyrrolidone (NMP), on morphology, porosity, bioactivity, degradation rate, and biocompatibility of the resulting scaffolds were investigated. <strong>Results:</strong> The results revealed that increasing the nano-hydroxyapatite (nHA) percentages had no significant effect on the porosity and interconectivity of scaffolds (<em>p</em> > 0.05), whereas altering the solvent from DIO into NMP decreased the porosity from about 87% into 71%, respectively. Moreover, scaffolds of DIO illustrated the high results of cell proliferation compared to those of NMP; the cell viability of GD25 decreased from 85% to 65% for GN25. The findings also indicated that scaffolds prepared by NMP had a higher rate of losing weight in comparison to DIO. Adding nHA to PLGA had a significant effect on the bioactivity of scaffolds (<em>p</em> < 0.05), composite scaffolds with 45 wt % nHA had at least 30% more weight gain compared to the neat polymer scaffolds. <strong>Conclusion:</strong> The DIO scaffolds have higher rates of porosity, interconnectivity, bioactivity, and biocompatibility than NMP scaffolds due to its high evaporation rate. Freeze drying, Porosity, Solvents 408 416 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-4300-1&slc_lang=en&sid=1 Neda Aboudzadeh aboudzadeh@iust.ac.ir 0000-0003-4927-9244 Yes Department of Materials Science and Engineering, Iran University of Science and Technology (IUST), Tehran, Iran Alireza Khavandi 0000-0001-5021-1162 No Department of Materials Science and Engineering, Iran University of Science and Technology (IUST), Tehran, Iran Jafar Javadpour 0000-0003-0159-9038 No Department of Materials Science and Engineering, Iran University of Science and Technology (IUST), Tehran, Iran Mohammad Ali Shokrgozar 0000-0001-5123-4155 No National Cell Bank of Iran, Pasteur Institute of Iran, Tehran, Iran Mohammad Imani 0000-0001-5154-0881 No 3Novel Drug Delivery Systems Dept., Iran Polymer and Petrochemical Institute, P.O.Box 14965/115, Tehran, Iran