title: Surface modification of 3D-printed porous scaffolds via mussel-inspired polydopamine and effective immobilization of rhBMP-2 to promote osteogenic differentiation for bone tissue engineering.
abstract: For tissue engineering, a bio-porous scaffold which is applied to bone-tissue regeneration should provide the hydrophilicity for cell attachment as well as provide for the capability to bind a bioactive molecule such as a growth factor in order to improve cell differentiation. In this work, we prepared a three-dimensional (3D) printed polycaprolactone scaffold (PCLS) grafted with recombinant human bone morphogenic protein-2 (rhBMP2) attached via polydopamine (DOPA) chemistry. The DOPA coated PCL scaffold was characterized by contact angle, water uptake, and X-ray photoelectron spectroscopy (XPS) in order to certify that the surface was successfully coated with DOPA. In order to test the loading and release of rhBMP2, we examined the release rate for 28days. For the In vitro cell study, pre-osteoblast MC3T3-E1 cells were seeded onto PCL scaffolds (PCLSs), DOPA coated PCL scaffold (PCLSD), and scaffolds with varying concentrations of rhBMP2 grafted onto the PCLSD 100 and PCLSD 500 (100 and 500ng/ml loaded), respectively. These scaffolds were evaluated by cell proliferation, alkaline phosphatase activity, and real time polymerase chain reaction with immunochemistry in order to verify their osteogenic activity. Through these studies, we demonstrated that our fabricated scaffolds were well coated with DOPA as well as grafted with rhBMP2 at a quantity of 22.7±5ng when treatment with 100ng/ml rhBMP2 and 153.3±2.4ng when treated with 500ng/ml rhBMP2. This grafting enables rhBMP2 to be released in a sustained pattern. In the in vitro results, the cell proliferation and an osteoconductivity of PCLSD 500 groups was greater than any other group. All of these results suggest that our manufactured 3D printed porous scaffold would be a useful construct for application to the bone tissue engineering field.
  
  
  
  Tissue-engineered scaffolds are not only extremely complex and cumbersome, but also use organic solvents which can negatively influence cellular function. Thus, a rapid, solvent-free method is necessary to improve scaffold generation. Recently, 3D printing such as a rapid prototyping technique has several benefits in that manufacturing is a simple process using computer aided design and scaffolds can be generated without using solvents. In this study, we designed a bio-active scaffold using a very simple and direct method to manufacture DOPA coated 3D PCL porous scaffold grafted with rhBMP2 as a means to create bone-tissue regenerative scaffolds. To our knowledge, our approach can allow for the generation of scaffolds which possessed good properties for use as bone-tissue scaffolds.
authors: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea; Department of Dental Materials, School of Dentistry, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea.
authors: Sang Jin
authors: SJ
authors: Lee
authors: Department of Dental Materials, School of Dentistry, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea.
authors: Donghyun
authors: D
authors: Lee
authors: Department of Orthopaedics Surgery, Chonnam National University Hwasun Hospital, 322 Seoyang-ro, Hwasun-eup, Hwasun-gun, Jeollanam-do 58128, Republic of Korea.
authors: Taek Rim
authors: TR
authors: Yoon
authors: Department of Orthopaedics Surgery, Chonnam National University Hwasun Hospital, 322 Seoyang-ro, Hwasun-eup, Hwasun-gun, Jeollanam-do 58128, Republic of Korea.
authors: Hyung Keun
authors: HK
authors: Kim
authors: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
authors: Ha Hyeon
authors: HH
authors: Jo
authors: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
authors: Ji Sun
authors: JS
authors: Park
authors: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
authors: Jun Hee
authors: JH
authors: Lee
authors: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea.
authors: Wan Doo
authors: WD
authors: Kim
authors: Department of Dental Materials, School of Dentistry, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea. Electronic address: kwoni@khu.ac.kr.
authors: Il Keun
authors: IK
authors: Kwon
authors: Department of Nature-Inspired Nanoconvergence Systems, Korea Institute of Machinery and Materials, 156 Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, Republic of Korea. Electronic address: psa@kimm.re.kr.
authors: Su A
authors: SA
authors: Park
mesh_terms: D000818:Animals; D055396:Bone Morphogenetic Protein 2 / Q000737:chemistry*; D002454:Cell Differentiation; D002460:Cell Line; D003692:Delayed-Action Preparations / Q000737:chemistry; D006801:Humans; D055767:Immobilized Proteins / Q000737:chemistry; D007211:Indoles / Q000737:chemistry*; D051379:Mice; D010012:Osteogenesis; D011108:Polymers / Q000737:chemistry*; D016062:Porosity; D066330:Printing, Three-Dimensional; D011994:Recombinant Proteins / Q000737:chemistry; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D003692:Delayed-Action Preparations; D055767:Immobilized Proteins; D007211:Indoles; D011108:Polymers; D011994:Recombinant Proteins; C568283:polydopamine
keywords: 3D-printing; Bone tissue engineering; Polycaprolactone; Recombinant human bone morphogenic protein-2