Poly(2-alkyl-2-oxazoline)-Heparin Hydrogels-Expanding the Physicochemical Parameter Space of Biohybrid Materials

Poly(ethylene glycol) (PEG)-glycosaminoglycan (GAG) hydrogel networks are established as very versatile biomaterials. Herein, the synthetic gel component of the biohybrid materials is systematically varied by combining different poly(2-alkyl-2-oxazolines) (POx) with heparin applying a Michael-type addition crosslinking scheme: POx of gradated hydrophilicity and temperature-responsiveness provides polymer networks of distinctly different stiffness and swelling. Adjusting the mechanical properties and the GAG concentration of the gels to similar values allows for modulating the release of GAG-binding growth factors (VEGF165 and PDGF-BB) by the choice of the POx and its temperature-dependent conformation. Adsorption of fibronectin, growth of fibroblasts, and bacterial adhesion scale with the hydrophobicity of the gel-incorporated POx. In vitro hemocompatibility tests with freshly drawn human whole blood show advantages of POx-based gels compared to the PEG-based reference materials. Biohybrid POx hydrogels can therefore enable biomedical technologies requiring GAG-based materials with customized and switchable physicochemical characteristics.

Automated summary

Poly(ethylene glycol) (PEG)-glycosaminoglycan (GAG) hydrogel networks are established as versatile biomaterials, with varying stiffness and swelling properties achieved through the systematic combination of different poly(2-alkyl-2-oxazolines) (POx) and heparin. The choice of POx and its temperature-dependent conformation can modulate the release of GAG-binding growth factors, while the hydrophobicity of the gel-incorporated POx influences fibronectin adsorption, fibroblast growth, and bacterial adhesion. In vitro hemocompatibility tests demonstrate advantages of POx-based gels over PEG-based reference materials. Biohybrid POx hydrogels have the potential to meet the requirements of biomedical technologies with customizable physicochemical characteristics.