After tooth extraction, uneven resorption of alveolar bone leads to soft tissue collapse, which hinders complete regeneration. Bone loss makes it more difficult to perform dental implants and restorations. Inspired by the biological structure of bones, a deformable SIS/HA (small intestinal submucosa/hydroxyapatite) composite hydrogel coaxial scaffold was designed to maintain bone mass in the alveolar socket. The SIS/HA scaffold contained GL13K as the outer layer, simulating compact bone, while the SIS hydrogel loaded with bone marrow mesenchymal stem cell-derived exosomes (BMSCs-Exos) as the inner core of the scaffold resembled the soft tissue in the bone. The coaxial scaffold exhibited an elastic modulus of 0.82 MPa, enabling it to adaptively fill the extraction socket and maintain the osteogenic space. At the same time, the BMSCs-Exos-rich inner layer of the composite scaffold promoted the proliferation and migration of human umbilical vein endothelial cells (HUVECs) and BMSCs into the scaffold interior (about 3 times that of the control group), and upregulated the expression of genes related to osteogenesis (BMP2, ALP, RUNX2, and OPN) and angiogenesis (HIF-1α and VEGF). This induced new blood vessels and bone growth in the scaffold, solving the problem of low bone formation rate in the center of the defect. GL13K released about 40.87±4.37% in the first three days, exerting a local antibacterial effect, further promoting vascularization and new bone formation in the surrounding area. The design aims to achieve a full range and efficient bone repair effect in the extraction socket through the internal and external dual mechanism of the coaxial scaffold.

Innovation:
1. The coaxial structure is used to simulate the hierarchical structure of natural bone tissue, realizing the spatial distribution and synergy of functions.
2. The SIS/HA composite material is cleverly combined with exosomes and antimicrobial peptides to create a multifunctional treatment platform.
3. Bone regeneration is promoted through the internal and external dual mechanism, solving the problem of insufficient regeneration in the central area of the traditional scaffold.

Inspiration from scientific research work:
1. When designing biomaterials, the structural characteristics and functional requirements of the target tissue should be deeply understood, and better treatment effects should be achieved through biomimetic design.
2. The synergistic effect of multi-component materials can achieve functions that cannot be achieved by a single material, which requires us to consider the interaction between the components when designing materials.
3. Solving complex biomedical problems requires systematic thinking, which requires considering both the physical properties of materials and biological effects.

Extension of ideas:
1. Explore the combination of other bioactive molecules and scaffolds to further optimize the bone regeneration effect.
2. Study the matching relationship between the degradation kinetics of scaffolds and the tissue regeneration process.
3. Develop scaffold materials with shape memory function to better adapt to irregular defects.
4. Explore the application potential of scaffolds in the repair of other types of bone defects.
5. Study the effect of material microstructure on cell behavior and optimize the structural design of scaffolds.
6. Develop new characterization methods to evaluate the performance and biological effects of materials.
7. Explore the personalized preparation of scaffolds by combining 3D printing technology.

8. Study the interaction between scaffolds and the host immune system to optimize the biocompatibility of materials.

Bioact. Mater. (IF 18)
Pub Date  : 2024-12-10
DOI : 10.1016/j.bioactmat.2024.12.008

Shiqing Ma, Yumeng Li, Shiyu Yao, Yucheng Shang, Rui Li, Lijuan Ling, Wei Fu, Pengfei Wei, Bo Zhao, Xuesong Zhang, Jiayin Deng