Chemical Engineering Journal 370(2019)573-586 Contents lists available at ScienceDirect HEMICAL RING JOURNAL Chemical Engineering Journ ELSEVIER journalhomepagewww.elsevier.com/locate/cej Synergistic effect of stem cells from human exfoliated deciduous teeth and rhBMP-2 delivered by injectable nanofibrous microspheres with different surface modifications on vascularized bone regeneration Tengjiaozi Fang, Zuoying Yuan", Yuming Zhao, Xiaoxia Li, Yue Zhai, Jingzhi Li, Xiaotong Wang Nanquan Rao, Lihong Ge@, Qing Cai, omatology, and Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China b State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China HIGHLIGHTS GRAPHICAL ABSTRACT We applied different surface mod- ifications on-demand to injectable NF- Bio-inspired hydro by PDa supported the cellular beha Ccaat cabo ance of NF-Ms in loading and delivering rhBMP-2. SHED engraftment contributes to an- giogenesis in ectopic and orthotopic Conjunctive use of SHED and rhBMP-2 led to vascularized bone tissue re. ARTICLE INFO ABSTRACT To provide a suitable 3D microenvironment for bone regeneration, we selected the injectable poly (l-lactic acid) anofibrous microspheres(PLLA NF-Ms) with different surface modifications to serve as cell micro-carriers or protein vehicles on-demand. Results showed that polydopamine(PDA)modified NF-Ms(PDA- NF-Ms) exhibited Stem cells from human exfoliated deciduous good affinity for stem cells from human exfoliated deciduous teeth(SHED), and Heparin-Dopamine(Hep-Dopa) teeth njugated with NF-Ms(Hep-Dopa NF-Ms)are able to immobilize and slowly release system morphogenic protein-2 (rhBMP-2)efficiently. In vivo evaluations were carried out in both ectopic subcutaneous plantation and orthotopic cranial bone defect nude mouse models (p= 4 mm). The results suggested that PDA-NF-Ms could support SHED survival over 4 weeks. All experimental groups with SHED/PDA-NF-Ms en- graftment showed angiogenesis activity. But, no effect of SHED/PDA-NF-Ms on osteogenesis was found in ec- topic implantation, which is different from the result in cranial defect. The rhBMP-2 released from Hep-Dopa NF. Ms could significantly guide bone tissue regeneration in both ectopic and orthotopic site. At 8 weeks, both BMP-2 group and dual group showed large amounts of bone formation in situ, despite the fact that quantitative results of micro-ct did not demonstrate significant difference between them. More blood vessels were observed in SHED and Dual groups, which verifies the quality improvement of regenerated osseous tissues. Re ascularized bone tissue was, thus, highly expected upon implanting SHED/PDA-NF-Ms and rhBMP-2-loaded Emst adress: gelihongos 0919@163.com(LGe),caiqing@mailbuct.edu.cn(Q.Cai https://doi.org/10.1016/j.cej.2019.03.151 Received 21 October 2018; Received in revised form 14 March 2019; Accepted 16 March 2019 ailable online 20 March 2019 1385.8947/C 2019 Elsevier B V. All rights reserved.Contents lists available at ScienceDirect Chemical Engineering Journal journal homepage: www.elsevier.com/locate/cej Synergistic effect of stem cells from human exfoliated deciduous teeth and rhBMP-2 delivered by injectable nanofibrous microspheres with different surface modifications on vascularized bone regeneration Tengjiaozi Fanga , Zuoying Yuanb , Yuming Zhaoa , Xiaoxia Lia , Yue Zhaia , Jingzhi Lia , Xiaotong Wanga , Nanquan Raoa , Lihong Gea,⁎ , Qing Caib,⁎ a Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, National Engineering Laboratory for Digital and Material Technology of Stomatology, and Beijing Key Laboratory of Digital Stomatology, Beijing 100081, China b State Key Laboratory of Organic-Inorganic Composites, Beijing Laboratory of Biomedical Materials, Beijing University of Chemical Technology, Beijing 100029, China HIGHLIGHTS • We applied different surface mod￾ifications on-demand to injectable NF￾Ms. • Bio-inspired hydrophilic modification by PDA supported the cellular beha￾vior. • Hep-Dopa conjugation improved per￾formance of NF-Ms in loading and delivering rhBMP-2. • SHED engraftment contributes to an￾giogenesis in ectopic and orthotopic sites. • Conjunctive use of SHED and rhBMP-2 led to vascularized bone tissue re￾generation. GRAPHICAL ABSTRACT ARTICLE INFO Keywords: Injectable nanofibrous microspheres Surface modification Stem cells from human exfoliated deciduous teeth Cell micro-carrier Sustained release system ABSTRACT To provide a suitable 3D microenvironment for bone regeneration, we selected the injectable poly (l-lactic acid) nanofibrous microspheres (PLLA NF-Ms) with different surface modifications to serve as cell micro-carriers or protein vehicles on-demand. Results showed that polydopamine (PDA) modified NF-Ms (PDA-NF-Ms) exhibited good affinity for stem cells from human exfoliated deciduous teeth (SHED), and Heparin-Dopamine (Hep-Dopa) conjugated with NF-Ms (Hep-Dopa NF-Ms) are able to immobilize and slowly release recombinant human bone morphogenic protein-2 (rhBMP-2) efficiently. In vivo evaluations were carried out in both ectopic subcutaneous implantation and orthotopic cranial bone defect nude mouse models (φ = 4 mm). The results suggested that PDA-NF-Ms could support SHED survival over 4 weeks. All experimental groups with SHED/PDA-NF-Ms en￾graftment showed angiogenesis activity. But, no effect of SHED/PDA-NF-Ms on osteogenesis was found in ec￾topic implantation, which is different from the result in cranial defect. The rhBMP-2 released from Hep-Dopa NF￾Ms could significantly guide bone tissue regeneration in both ectopic and orthotopic site. At 8 weeks, both BMP-2 group and dual group showed large amounts of bone formation in situ, despite the fact that quantitative results of micro-CT did not demonstrate significant difference between them. More blood vessels were observed in SHED and Dual groups, which verifies the quality improvement of regenerated osseous tissues. Regeneration of vascularized bone tissue was, thus, highly expected upon implanting SHED/PDA-NF-Ms and rhBMP-2-loaded https://doi.org/10.1016/j.cej.2019.03.151 Received 21 October 2018; Received in revised form 14 March 2019; Accepted 16 March 2019 ⁎ Corresponding authors. E-mail addresses: gelihong0919@163.com (L. Ge), caiqing@mail.buct.edu.cn (Q. Cai). Chemical Engineering Journal 370 (2019) 573–586 Available online 20 March 2019 1385-8947/ © 2019 Elsevier B.V. All rights reserved. T