Acceleration of bone formation using in situ-formed hyaluronan-hydrogel containing bone morphogenetic protein-2 in a mouse critical size bone defect model

2021 ◽  
pp. 1-9
Author(s):  
Shintaro Shoji ◽  
Kentaro Uchida ◽  
Ryo Tazawa ◽  
Wataru Saito ◽  
Akiyoshi Kuroda ◽  
...  

BACKGROUND: An enzymatic crosslinking strategy using hydrogen peroxide and horseradish peroxidase is receiving increasing attention for application with in situ-formed hydrogels (IFHGs). IFHGs may also be ideal carrier materials for bone repair, although their ability to carry bone morphogenetic protein-2 (BMP2) has yet to be examined. OBJECTIVE: We examined the effectiveness of an IFHG made of hyaluronan (IFHG-HA) containing BMP2 for promoting bone formation in a mouse critical size bone defect model. METHODS: C57/BL6J mice received a 2-mm femoral critical-sized bone defect before being randomly assigned to one of the following treatment groups (n = 6): control (no treatment), IFHG-HA only, PBS with BMP2, and IFHG-HA with BMP2. X-ray radiographs were utilized to track new bone formation, and micro-computed tomography and histological examination were performed on new bone formed at the bone defect site two weeks after surgery. RESULTS: Mice treated with PBS with BMP2 and IFHG-HA with BMP2 had greater bone volume (BV) and bone mineral content (BMC) than those receiving control, and successfully achieved consolidation. Mice treated with IFHG-HA with BMP2 had significantly higher BV and BMC than those treated with PBS with BMP2. CONCLUSIONS: IFHG-HA may be an effective carrier for BMP2 to enable delivery for bone defect repair.

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Shintaro Shoji ◽  
Kentaro Uchida ◽  
Wataru Satio ◽  
Hiroyuki Sekiguchi ◽  
Gen Inoue ◽  
...  

Abstract Background An enzymatic crosslinking strategy using hydrogen peroxide and horseradish peroxidase is receiving increasing attention for application with in situ-formed hydrogels (IFHs). Several studies have reported the application of IFHs in cell delivery and tissue engineering. IFHs may also be ideal carrier materials for bone repair, although their potential as a carrier for bone morphogenetic protein (BMP)-2 has yet to be examined. Here, we examined the effect of an IFH made of hyaluronic acid (IFH-HA) containing BMP-2 in promoting osteogenesis in a mouse refractory fracture model. Methods Immediately following a fracture procedure, animals either received no treatment (control) or an injection of IFH-HA/PBS or IFH-HA containing 2 μg BMP-2 (IFH-HA/BMP-2) into the fracture site (n = 16, each treatment). Results Fracture sites injected with IFH-HA/BMP-2 showed significantly greater bone volume, bone mineral content, and bone union compared with sites receiving no treatment or treated with IFH-HA/PBS alone (each n = 10). Gene expression levels of osteogenic markers, Alpl, Bglap, and Osx, were significantly raised in the IFH-HA/BMP-2 group compared to the IFH-HA/PBS and control groups (each n = 6). Conclusion IFH-HA/BMP-2 may contribute to the treatment of refractory fractures.


2021 ◽  
Vol 9 (A) ◽  
pp. 1132-1136
Author(s):  
Respati S. Dradjat ◽  
Panji Sananta ◽  
Rizqi Daniar Rosandi ◽  
Lasa Dhakka Siahaan

BACKGROUND: Fractures and segmental bone defects are a significant cause of morbidity and a source of a high economic burden in healthcare. A severe bone defect (3 mm in murine model) is a devastating condition, which the bone cannot heal naturally despite surgical stabilization and usually requires further surgical intervention. The stromal vascular fraction (SVF) contains a heterogeneous collection of cells and several components, primarily: MSCs, HSCs, Treg cells, pericytic cells, AST cells, extracellular matrix, and complex microvascular beds (fibroblasts, white blood cells, dendritic cells, and intra-adventitial smooth muscular-like cells). Bone morphogenetic protein (BMP) is widely known for their important role in bone formation during mammalian development and confers a multifunctional role in the body, which has potential for therapeutic use. Studies have shown that BMPs play a role in the healing of large size bone defects. AIM: In this study, researchers aim to determine the effect of administering SVF from adipose tissue on the healing process of bone defects assessed based on the level biomarker of BMP-2. MATERIALS AND METHODS: This was an animal study involving 12 Wistar strain Rattus norvegivus. They were divided into three groups: Negative group (normal rats), positive group (rats with bone defect without SVF application), and SVF group (rats with bone defect with SVF application). After 30 days, the rats were sacrificed; the biomarkers that were evaluated are BMP-2. This biomarker was quantified using ELISA. RESULTS: BMP-2 biomarker expressions were higher in the SVF application group than in the group without SVF. All comparisons of the SVF group and positive control group showed significant differences (p = 0.026). CONCLUSION: SVF application could aid the healing process in a murine model with bone defect marked by the increased level of BMP-2 as a bone formation marker.


2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Ryo Tazawa ◽  
Kentaro Uchida ◽  
Hiroaki Minehara ◽  
Terumasa Matsuura ◽  
Tadashi Kawamura ◽  
...  

Abstract Background Delivery of bone morphogenetic protein-2 (BMP-2) via animal-derived absorbable collagen materials is used for the treatment of large bone defects. However, the administration of bovine proteins to humans is associated with the risk of zoonotic complications. We therefore examined the effect of combining BMP-2 with collagen-like peptides, poly(POG)n, in a critical-sized bone defect mouse model. Methods A 2-mm critical-sized bone defect was created in the femur of 9-week-old male C57/BL6J mice. Mice were randomly allocated into one of four treatment groups (n = 6 each): control (no treatment), poly(POG)n only, 0.2 μg, or 2.0 μg BMP-2 with poly(POG)n. New bone formation was monitored using soft X-ray radiographs, and bone formation at the bone defect site was examined using micro-computed tomography and histological examination at 4 weeks after surgery. Results Administration of 2.0 μg of BMP-2 with poly(POG)n promoted new bone formation and resulted in greater bone volume and bone mineral content than that observed in the control group and successfully achieved consolidation. In contrast, bone formation in all other groups was scarce. Conclusions Our findings suggest the potential of BMP-2 with poly(POG)n as a material, free from animal-derived collagen, for the treatment of large bone defects.


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