The present disclosure relates generally to hydrogel biomaterials. In particular, the present disclosure is directed to compositions and methods for developing hydrolytically degradable hydrogels.

It is provided a method of treatment of a human or animal patient in need thereof to achieve a reduction of the viscosity of mucus of the patient which is carried out by administering a polyglycerol derivative having a linear or dendritic polyglycerol backbone and carrying at least one thiol group covalently bound to the polyglycerol backbone. It is further provided a method of treatment of a human or animal patient suffering from chronic sinusitis, asthma, chronic bronchitis, cystic fibrosis, chronic obstructive pulmonary disease, emphysema, bronchiectasis, chronic inflammatory bowel diseases, constipation, gastrointestinal malabsorption syndrome, irritable bowel syndrome, steatorrhea or diarrhea by administering a polyglycerol derivative. Further specific thiol-functionalized polyglycerol derivatives and a corresponding manufacturing method are provided.