Tissue adhesives and sealants which are formed by reacting a polyglycerol aldehyde with the water-dispersible multi-arm amine is described. This tissue adhesives and sealants, wound closure, supplement or replacement of sutures or staples in internal surgical procedures, such as intestinal anastomosis and vascular anastomosis, tissue repair, blood, bile, preventing leakage of fluid, such as gastrointestinal fluid and cerebrospinal fluid , eye surgery, drug delivery, and including preventing post-surgical adhesions, but are not limited to, may be useful for medical and veterinary applications.