Photocurable Crosslinker from Bio-Based Non-Isocyanate Poly(hydroxyurethane) for Biocompatible Hydrogels

Area of Science:

• Polymer Chemistry
• Biomaterials Science
• Green Chemistry

Background:

• Traditional polyurethanes often involve toxic isocyanates.
• There is a growing demand for sustainable and biocompatible materials in the medical field.
• Developing light-curable polymers from renewable resources is crucial for advanced biomedical applications.

Purpose of the Study:

• To synthesize photocurable non-isocyanate polyhydroxyethylurethanes (BPHUs) from renewable feedstocks.
• To develop both aliphatic and aromatic BPHU variants for diverse biomedical applications.
• To evaluate the properties and biocompatibility of the synthesized BPHUs for potential use in medical devices.

Main Methods:

• Two synthetic routes were established: an aliphatic pathway using 1,4-butanediol-derived cyclic carbonates and an aromatic pathway using resorcinol-based carbonates.
• Ring-opening polymerization with dodecanediamine followed by methacrylation yielded photoreactive BPHU derivatives.
• Characterization involved NMR, GPC, and FTIR; UV curing produced hydrogels, and swelling properties were assessed. Cytotoxicity was evaluated per DIN EN ISO 10993-5.

Main Results:

• Successful synthesis of aliphatic and aromatic BPHU intermediates and their methacrylated derivatives was confirmed.
• UV curing resulted in hydrogels with significant swelling: aliphatic BPHUs (91.3% gel content, 1057% swelling) and aromatic BPHUs (78.1% gel content, 3304% swelling).
• Both BPHU variants exhibited non-cytotoxicity, with >80% cell viability, indicating suitability for biomedical applications.

Conclusions:

• Renewable-source-based BPHUs offer a versatile and eco-friendly alternative to conventional polyurethanes.
• The tunable mechanical properties (flexibility vs. rigidity) make these BPHUs suitable for a range of biomedical applications, from adaptable implants to load-bearing devices.
• This research highlights the potential of green chemistry in developing advanced, biocompatible materials for next-generation medical devices.