The Paper on Injectable Dendritic Hydrogels in Bone Regeneration has been Published in the Journal of the American Chemical Society

Researchers at the Royal Institute of Technology (KTH) and the University of Bergen (UiB) have developed a novel platform for an injectable bone scaffold hydrogel. The hydrogel cures in situ via high-energy visible (HEV) light-induced thiol-ene coupling (TEC) chemistry. In vitro cytocompatibility assessments have revealed the platform supports bone marrow mesenchymal stem cell (BMSC) viability and interactions, comparable to a control hydrogel gelatin methcryloyl (GelMA).

The newly developed hydrogel platform presents a highly tuneable solution, offering greater control over mechanical properties and degradation rates. The pivotal feature of curing in situ enables injection directly into the bone fracture for supported and accelerated bone tissue regeneration. Their work presents a promising approach for bone tissue regeneration, particularly in complex and shattered fractures above the critical length of natural bone tissue connectivity.

Central to the innovation is the precise and controlled synthesis of dendritic-linear-dendritic (DLD) building blocks. This enables the high tunability of the hydrogel’s mechanical properties and batch-to-batch consistency. By varying the batch’s generation of dendritic component, the number of allyl groups per DLD involved in TEC reactions are altered, allowing control over the crosslink density of the hydrogel.  

In the paper published, different formulations of hydrogels were prepared to assess the influence of DLD generation and dry content across parameters such as gel swelling, degradation and storage modulus. To further enhance functional versatility of the platform, hydrogels were successfully incorporated with bioactive components hydroxyapatite microparticles or collagen. These modifications strengthen the potential of the DLD-based platform for applications beyond bone scaffolds, offering a customisable foundation for broader tissue engineering adaptations.

In vitro compatibility studies reflect that hydrogels’ support for viability and proliferation of BMSCs, whilst presenting a versatile and high-performing foundation for injectable biomaterials in regenerative medicine/ tissue engineering.

The paper describing the injectable dendritic hydrogels  can be accessed via https://pubs.acs.org/doi/full/10.1021/acs.chemmater.5c00063. The data used in the paper has also been uploaded to an open data repository, which can be found at https://zenodo.org/records/13919543.