3D-printable biodegradable hybrids based on ABA-triblock copolymers synthesised by RAFT polymerisation
File(s)
Accepted version
Author(s)
Jones, Julian
Type
Journal Article
Abstract
There is unmet clinical need for advanced biomaterials that can promote bone regeneration through
three-dimensional (3D) scaffold architectures. Hybrid inorganic/organic biomaterials are promising due to their nanoscale interactions between amorphous polymeric and silica networks, that can provide resistance to cyclic loading and tuneable biodegradability. Our aim was to develop novel biodegradable silica/polymer scaffolds based on P(MMA-co-TMSPMA)-b-PCL-b P(MMA-co-TMSPMA) triblock copolymers as the organic component. Triblock copolymers produced by RAFT polymerisation were chosen over linear polymers to balance controlled
biodegradation with mechanical strength. Optimal compositions were 70 wt% nominal organic content using triblock copolymers synthesised from the 5 kDa PCL based RAFT agent, which exhibited the highest yield strength (compression) of 58 MPa (true stress) at 5% strain. Scaffolds with interconnected pore sizes of 250 - 300 μm were 3D printed from the hybrid ink via direct ink writing (DIW). Optimal printability was achieved for triblock copolymers with molecular masses
between 15,000 and 17,000 g·mol⁻¹ (using PCL of 5 kDa) and they exhibited mechanical properties and porosity comparable to those of trabecular bone, e.g. yield strength of 10±0.5 MPa at a yield strain of 4±0.3%, and showed ~23% degradation over two months. In vitro studies confirmed the scaffolds were not toxic to human bone marrow stromal cells.
three-dimensional (3D) scaffold architectures. Hybrid inorganic/organic biomaterials are promising due to their nanoscale interactions between amorphous polymeric and silica networks, that can provide resistance to cyclic loading and tuneable biodegradability. Our aim was to develop novel biodegradable silica/polymer scaffolds based on P(MMA-co-TMSPMA)-b-PCL-b P(MMA-co-TMSPMA) triblock copolymers as the organic component. Triblock copolymers produced by RAFT polymerisation were chosen over linear polymers to balance controlled
biodegradation with mechanical strength. Optimal compositions were 70 wt% nominal organic content using triblock copolymers synthesised from the 5 kDa PCL based RAFT agent, which exhibited the highest yield strength (compression) of 58 MPa (true stress) at 5% strain. Scaffolds with interconnected pore sizes of 250 - 300 μm were 3D printed from the hybrid ink via direct ink writing (DIW). Optimal printability was achieved for triblock copolymers with molecular masses
between 15,000 and 17,000 g·mol⁻¹ (using PCL of 5 kDa) and they exhibited mechanical properties and porosity comparable to those of trabecular bone, e.g. yield strength of 10±0.5 MPa at a yield strain of 4±0.3%, and showed ~23% degradation over two months. In vitro studies confirmed the scaffolds were not toxic to human bone marrow stromal cells.
Date Acceptance
2026-08-16
Citation
Materials Advances
ISSN
2633-5409
Publisher
The Royal Society of Chemistry
Journal / Book Title
Materials Advances
Copyright Statement
Copyright This paper is embargoed until publication. Once published the Version of Record (VoR) will be available on immediate open access.
License URL
Publication Status
Accepted