A new hydrogel made of crosslinked glycosaminoglycans, particularly crosslinked hyaluronic acid, chondroitin or chondroitin sulfate, having reversible linkages using boronic acid or boroxole derivatives leading to new benefits. Glycosaminoglycans that are crosslinked via an alkoxyboronate ester anion formed between a diol portion of a diol-functional moiety grafted to a first glycosaminoglycan and a boronate hemiester grafted to a second glycosaminoglycan.