Functional nanofiber mat of polyvinyl alcohol/gelatin containing nanoparticles of biphasic calcium phosphate for bone regeneration in rat calvaria defects Nguyen Thuy Ba Linh, 1 Kap-Ho Lee, 2 Byong-Taek Lee 1,3 1 Department of Biomedical Eng. & Mater., College of Medicine, Soonchunhyang University, 366-1 Ssangyong dong, Cheonan, 330-090, South Korea 2 Department of Nanomaterials Engineering, College of Engineering, Chungnam National University, Yuseong-Gu, Daejon 305, South Korea 3 Institute of Tissue Regeneration, College of Medicine, Soonchunhyang University, 366-1 Ssangyong Dong, Cheonan, 330-090, South Korea Received 10 September 2012; revised 14 November 2012; accepted 15 November 2012 Published online 17 May 2013 in Wiley Online Library (wileyonlinelibrary.com). DOI: 10.1002/jbm.a.34533 Abstract: New biodegradable mats was successfully obtained by functional polyvinyl alcohol (PVA)/Gelatin (GE) blend fiber mats containing different BCP amounts (20, 40, and 50 w/v%) of bipha- sic calcium phosphate (BCP) nanoparticles for bone regeneration. BCP nanoparticles were loaded and dispersed successfully in the PVA/GE fibrous matrix. The addition of BCP was found to have increased fiber diameter, tensile strength, osteoblast cell adhesion, proliferation, and protein expression. Compared to the others, the 50% BCP-loaded electrospun PVA/GE fibers had the most favor- able mechanical properties, cell attachment and growth, and pro- tein expression. In vivo bone formation was examined using rat models, and increased bone formation was observed for the 50% BCP-loaded electrospun PVA/GE blends within 2 and 4 weeks. This result suggests that the 50% BCP-PVA/GE composite nano- fiber mat has high potential for use in the field of bone regenera- tion and tissue engineering. V C 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 2412–2423, 2013. Key Words: electrospinning, polyvinyl alcohol, gelatin, bipha- sic calcium phosphate, bone tissue engineering How to cite this article: Linh NTB, Lee K-H, Lee B-T. 2013. Functional nanofiber mat of polyvinyl alcohol/gelatin containing nanoparticles of biphasic calcium phosphate for bone regeneration in rat calvaria defects. J Biomed Mater Res Part A 2013:101A:2412–2423. INTRODUCTION Bone is one of the largest tissues in the human body, and has interconnected porous structures comprising biological apatite, collagenous and noncollagenous proteins and other essential trace elements. Artificial bone substitutes or scaf- folds are designed in a way that provides a framework for natural bone with adequate mechanical and biological prop- erties. However, several requirements must be met before a scaffold system becomes clinically valid for usage. An artifi- cial bone substitute or scaffold should be mechanically strong, contain macro- and micro-pores with high surface area, be biodegradable, biocompatible, and nontoxic, and should not evoke strong immunogenic reactions upon im- plantation into the body. Polymeric fibers generated by electrospinning technique have attracted much attention in tissue engineering 1–4 due to their relative biocompatibility, intrinsic biodegradability, nontoxicity, availability, and ease of applicability. 2,5–8 The fibril alignment of collagen proteins in the natural extracel- lular matrix component of bone can be obtained in poly- meric fiber mats using electrospinning. 9 Additionally, two important criteria for scaffold designing, the generation of micro- to nanoscale porosity and high surface to volume ra- tio are easily achievable through this technique. Although used in 1934 textiles, electrospinning has been adopted very quickly and used vigorously in the field of biomedical applications in the last few decades, such as drug delivery, scaffold designing, wound dressings, and coatings. 8 In some of our previous studies, we used electrospinning methods successfully for bone tissue engineering by generating poly- vinyl alcohol/gelatin (PVA/GE) fiber mats 10,11 or for coating the surfaces of ceramic scaffolds. 12,13 In one previous study, we showed that PVA and GE can be successfully electrospun for bone tissue engineering. However, mechanical strength of PVA/GE was not supportive for ideal bone regeneration. In the current study, we have improved the system by add- ing biphasic calcium phosphate (BCP) for further stability and improved mechanical and biological properties. Polyvinyl alcohol has been used in tissue engineering because of its biocompatibility, degradability, and nontoxicity. PVA has been successfully used in drug delivery system (DDS) for controlled delivery, 14–16 in injectable bone substitute (IBS) Correspondence to: B.-T. Lee; e-mail: lbt@sch.ac.kr Contract grant sponsors: Korea Health Technology R&D project, Ministry of Health & Welfare, Republic of Korea (A111084) 2412 V C 2013 WILEY PERIODICALS, INC.