d e n t a l m a t e r i a l s 3 4 ( 2 0 1 8 ) 538–550 Available online at www.sciencedirect.com ScienceDirect jo ur nal ho me pag e: www.intl.elsevierhealth.com/journals/dema Development of layered PLGA membranes for periodontal tissue regeneration Itsumi Yoshimoto a , Jun-Ichi Sasaki a,∗ , Ririko Tsuboi a,b , Satoshi Yamaguchi a , Haruaki Kitagawa a , Satoshi Imazato a a Department of Biomaterials Science, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan b Division for Interdisciplinary Dentistry, Osaka University Dental Hospital, 1-8 Yamadaoka, Suita, Osaka 565-0871, Japan a r t i c l e i n f o Article history: Received 3 October 2017 Received in revised form 30 November 2017 Accepted 21 December 2017 Keywords: Biodegradable membrane Barrier membrane Guided tissue regeneration PLGA Bone regeneration a b s t r a c t Objective. Various commercial products are available for guided tissue regeneration (GTR) therapy; however, they do not combine biosafety with the ability to control cell function. The purpose of this study was to evaluate the physicochemical and biological charac- teristics of the novel bilayer biodegradable poly(lactic-co-glycolic acid) (PLGA) membrane, and to assess whether the bilayer PLGA membrane could be used for periodontal tissue regeneration. Methods. Bilayer biodegradable membrane was fabricated thorough a two-step freezing and lyophilization process using PLGA solution. The characteristics of bilayer mem- branes were evaluated with respect to surface morphology, stability, mechanical strength, and operability for clinical use. Cell proliferation and osteogenic differentiation were investigated on the each surface of bilayer membrane. Then, these membranes were implanted to the rat calvaria bone defect models and evaluated their capability for tissue regeneration. Results. Biodegradable membranes composed of the solid and porous layer were successfully prepared and the surface morphologies analyzed. Physicochemical analyses revealed that the membranes possessed enough stability and mechanical properties for clinical use. It was also confirmed that the solid layer inhibited cell proliferation and subsequent connective tissue invasion, while the inner layer promoted proliferation and osteogenic differentiation, thus resulting in bone regeneration in vivo. Significance. The layering technology used to fabricate the bilayer polymer membrane could be applied in the developing of other novel biomaterials. The present study demonstrates that the bilayer biodegradable polymer membranes facilitate tissue regeneration in vivo, and therefore represent a prospective biomaterial for GTR therapy. © 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. ∗ Corresponding author. E-mail address: jun1-s@dent.osaka-u.ac.jp (J.-I. Sasaki) . https://doi.org/10.1016/j.dental.2017.12.011 0109-5641/© 2018 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.