Promoting osteoblast proliferation on polymer bone substitutes with bone-like structure by combining hydroxyapatite and bioactive glass.
Mimicking the structural features of natural bone has been demonstrated to bring pronounced advantages for mechanical reinforcement of polymeric orthopedic substitutes that are composed of bioinert polymer matrix and bioactive fillers. However, to trigger effective bone formation and implant integration, the bioactivity of bone substitutes plays a vital role. We hypothesized that the use of hydroxyapatite (HA) and bioactive glass (BG), compared to the use of HA alone, could improve the biological properties of polymer-based bone substitutes. Herein, high-density polyethylene (PE) composites loaded with HA and BG were fabricated using a modified injection molding machine that can provide intense shear flow to regulate the hierarchical structure of the composites. Morphological observation revealed that bone-like structures were formed in both HA/PE and BG/HA/PE composites, showing highly oriented interlocked shish kebabs. In addition, the bioactive fillers were distributed uniformly. Osteoblast proliferation was promoted by the combination of HA and BG. The mechanism was the upregulation of Runx2 expression (1.51 ± 0.17) with BG and the activation of the TAZ/YAP (1.41/0.64) signaling pathway, which accelerated the generation of ossification-related proteins. BG can regulate microRNA to promote the mRNA expression of Runx2. The silencing of Runx2 expression can inhibit BG-induced osteoblast proliferation. These results suggest that the BG/HA/PE composites having a bone-like structure have high potential as bone substitutes to repair large bone defects.
['Zhao|Baisong|B|', 'Xu|Haiping|H|', 'Gao|Ying|Y|', 'Xu|Jia-Zhuang|JZ|', 'Yin|Hua-Mo|HM|', 'Xu|Ling|L|', 'Li|Zhong-Ming|ZM|', 'Song|Xingrong|X|']
D000217:Acyltransferases D048868:Adaptor Proteins, Signal Transducing D000818:Animals D018786:Bone Substitutes D018797:Cell Cycle Proteins D002460:Cell Line D049109:Cell Proliferation D002516:Ceramics D050659:Core Binding Factor Alpha 1 Subunit D017886:Durapatite D005786:Gene Expression Regulation D051379:Mice D010006:Osteoblasts D010750:Phosphoproteins D020959:Polyethylene D014157:Transcription Factors D000091102:YAP-Signaling Proteins
Osteoblast proliferation Bone substitute Bone-like structure Hydroxyapatite Bioactive glass