A chitosan-based composite scaffold as a bioactive strontium-delivery system mediating accelerated bone regeneration
Jiyang Zeng1, Wei Li2, Yawei Li1
1Department of Spine Surgery, Second Xiangya Hospital of Central South University, Changsha, 410011, China; Hunan Digital Spine Research Institute, Department of Science and Technology of Hunan Province, Changsha, 410011, China.
Carbohydrate Polymers
|March 14, 2026
Summary
This study introduces a novel composite scaffold (CS/SF@SrAlg) for bone regeneration. It significantly enhances bone healing in animal models by promoting cell growth and new bone formation.
Area of Science:
- Biomaterials Science
- Orthopaedic Surgery
- Tissue Engineering
Background:
- Bone defects pose significant clinical challenges due to limitations of current bone graft materials.
- Existing materials often exhibit inadequate osteogenic capacity, donor site morbidity, and poor mechanical strength.
- There is a critical need for advanced biomaterials to improve bone regeneration outcomes.
Purpose of the Study:
- To develop and evaluate a novel composite bone regeneration scaffold (CS/SF@SrAlg).
- To assess the scaffold's biocompatibility, mechanical properties, and efficacy in promoting osteogenesis.
- To elucidate the underlying molecular mechanisms of scaffold-mediated bone regeneration.
Main Methods:
- Fabrication of a composite scaffold using chitosan, silk fibroin fibers, and strontium alginate microspheres via microfluidic electrospray and fiber fragmentation-recombination.
- In vitro assessment of cell proliferation, migration, and osteogenic mineralization.
- In vivo evaluation in a rat calvarial defect model to quantify bone regeneration, angiogenesis, and osteogenesis.
- RNA transcriptomics analysis to identify key signaling pathways involved in osteogenesis.
Main Results:
- The CS/SF@SrAlg scaffold demonstrated excellent biocompatibility, enhanced mechanical properties, and controlled strontium ion release.
- In vitro studies showed significant enhancement in cell proliferation (>120%) and osteogenic differentiation.
- In vivo results indicated substantial bone regeneration (81.8% ± 1.48% coverage at 8 weeks) and robust angiogenesis.
- Transcriptomic analysis revealed modulation of the PI3K-Akt signaling pathway, promoting osteogenesis.
Conclusions:
- The developed CS/SF@SrAlg composite scaffold is a promising biomaterial for repairing bone defects.
- Its hierarchical porous structure, mechanical integrity, and strontium release contribute to enhanced osteogenesis and angiogenesis.
- The scaffold shows significant potential for clinical translation in orthopaedic applications.
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