The repair of large bone defects can be a challenging task in medicine. While scaffolding materials can help to promote bone growth, the resulting bone constructs often suffer from insufficient vascularization, i.e., too few blood vessels are formed. Gelatin microspheres (GMSs) can be used in tissue engineering scaffolding materials.
Dong-An Wang, City University of Hong Kong, Kowloon, Hong Kong SAR, China, Shenzhen Research Institute, China, Changjiang Fan, Qingdao University, Shandong, China, and colleagues have found that scaffolds made of chemically crosslinked gelatin microsphere aggregates (C-GMSs) promote vascularized bone regeneration and could help to repair large bone defects. The team prepared chemically crosslinked gelatin microspheres via an EDC/NHS-mediated covalent crosslinking of carboxyl groups and amine groups in gelatin (EDC = N-ethyl-N‘-(3-(dimethylamino)propyl)carbodiimide, NHS = N-hydroxysuccinimide).
The resulting C-GMSs were placed in cell cultures with human aortic endothelial cells (HAECs, typical angiogenic cells) and MC3T3-E1 cells (typical osteogenic cells) in vitro. The team also implanted acellular C-GMSs (without pre-loaded cells and growth factors) into defects in the femoral bones of rats. They used a microporous gel as a control scaffold.
The researchers found that the C-GMSs scaffold succeeded in inducing the formation of vascularized bone tissue (schematically pictured). The C-GMSs form a loosely packed structure, which allows for cell migration into the scaffold center. The large cell-adhesive surfaces and interconnected macropores enhance the adhesion, proliferation, and differentiation of the cells. The acellular C-GMSs constructs achieved the effective restoration of defects in rat bones and integration with the surrounding host bone.
- Biomaterial Scaffolds Made of Chemically Cross‐Linked Gelatin Microsphere Aggregates (C‐GMSs) Promote Vascularized Bone Regeneration,
Peiyan Wang, Xinyue Meng, Runze Wang, Wei Yang, Lanting Yang, Jianxun Wang, Dong‐An Wang, Changjiang Fan,
Adv. Healthcare Mater. 2022.