title: Vascularization of plastic calcium phosphate cement in vivo induced by in-situ-generated hollow channels.
abstract: Despite calcium phosphate cement (CPC) is promising for bone repair therapy, slow biodegradation and insufficient vascularization in constructs negatively impacts its clinical application. A self-setting CPC composited with gelatin fiber is investigated to test the utility of this tissue engineering strategy to support rapid and extensive vascularization process. The interconnected hollow channels in CPC are formed after dissolution of gelatin fibers in vivo. The CPC-gelatin samples exhibit relatively decent/enhanced mechanical property, compared to the control. When implanted in vivo, the pre-established vascular networks in material anastomose with host vessels and accelerate vascular infiltration throughout the whole tissue construct. Different channel sizes induce different vascularization behaviors in vivo. Results indicate that the channel with the size of 250μm increases the expression of the representative angiogenic factors HIF1α, PLGF and migration factor CXCR4, which benefit the formation of small vessels. On the other hand, the channel with the size of 500μm enhances VEGF-A expression, which benefit the development of large vessels. Notably, the intersection area of channels has high invasive, sprouting and vasculogenesis potential under hypoxic condition, because more HIF1α-positive cells are observed there. Observation of the CD31-positive lumen in the border of scaffold indicates the ingrowth of blood vessels from its host into material through channel, benefited from gradually increased HIF1α expression. This kind of material was suggested to promote the effective application of bone regeneration through the combination of in situ self-setting, plasticity, angiogenesis, and osteoconductivity.
authors: College of Science and Engineering, Jinan University, Guangzhou, PR China. Electronic address: ytbiom@hotmail.com.
authors: Tao
authors: T
authors: Yu
authors: Department of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, PR China.
authors: Chao
authors: C
authors: Dong
authors: National Engineering Center for Tissue Reconstruction and Restoration, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, PR China.
authors: Zhonghua
authors: Z
authors: Shen
authors: Department of Ultrasound, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, PR China.
authors: Yan
authors: Y
authors: Chen
authors: Department of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, PR China. Electronic address: gzyubo@163.com.
authors: Bo
authors: B
authors: Yu
authors: National Engineering Center for Tissue Reconstruction and Restoration, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, PR China.
authors: Haishan
authors: H
authors: Shi
authors: College of Science and Engineering, Jinan University, Guangzhou, PR China.
authors: Changren
authors: C
authors: Zhou
authors: National Engineering Center for Tissue Reconstruction and Restoration, School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641, PR China.
authors: Jiandong
authors: J
authors: Ye
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000737:chemistry / Q000494:pharmacology; D002130:Calcium Phosphates / Q000737:chemistry / Q000494:pharmacology; D005260:Female; D020007:Implants, Experimental; D008422:Materials Testing; D018919:Neovascularization, Physiologic / Q000187:drug effects*; D016062:Porosity; D051381:Rats; D017207:Rats, Sprague-Dawley; D054457:Tissue Scaffolds / Q000737:chemistry*
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; C020243:calcium phosphate
keywords: Calcium phosphate cement; Gelatin fiber; HIF1α; Tissue engineering; Vascularization