I‐Optimal design of poly(lactic‐co‐glycolic) acid/hydroxyapatite three‐dimensional scaffolds produced by thermally induced phase separation

Abstract

In bone tissue engineering, three‐dimensional (3D) scaffolds are often designed to have adequate modulus while taking into consideration the requirement for a highly porous network for cell seeding and tissue growth. This article presents the design optimization of 3D scaffolds made of poly(lactic‐co‐glycolic) acid (PLGA) and nanohydroxyapatite (nHA), produced by thermally induced phase separation (TIPS). Slow cooling at a rate of 1°C/min enabled a uniform temperature and produced porous scaffolds with a relatively uniform pore size. An I‐optimal design of experiments (DoE) with 18 experimental runs was used to relate four responses (scaffold thickness, density, porosity, and modulus) to three experimental factors, namely the TIPS temperature (−20, −10, and 0°C), PLGA concentration (7%, 10%, and 13% w/v), and nHA content (0%, 15%, and 30% w/w). The response surface analysis using JMP® software predicted a temperature of −18.3°C, a PLGA concentration of 10.3% w/v, and a nHA content of 30% w/w to achieve a thickness of 3 mm, a porosity of 83%, and a modulus of ~4 MPa. The set of validation scaffolds prepared using the predicted factor levels had a thickness of 3.05 ± 0.37 mm, a porosity of 86.8 ± 0.9%, and a modulus of 3.57 ± 2.28 MPa. POLYM. ENG. SCI., 59:1146–1157 2019. © 2019 Society of Plastics Engineers