Synthesis of chitosan aerogels as promising carriers for drug delivery: A review

•The preparation of chitosan aerogels from acidic aqueous solution is intensively studied.•The synthesis of chitosan aerogels from chitosan solution in ILs is covered.•Specific studies on chitosan aerogels as drug delivery carriers are reviewed.•Future trends of chitosan aerogels in drug delivery system are described. Chitosan with abundant functional groups is regarded as important ingredients for preparing aerogel materials in life science. The biocompatibility and biodegradability of chitosan aerogels, coupled to the variety of chemical functionalities they include, result in them promising carriers for drug delivery. Moreover, chitosan aerogels as drug delivery vehicles can offer improved drug bioavailability and drug loading capacity due to their highly porous network, considerably large specific surface area and polycationic feature. The major focus of this review lies in preparation methods of chitosan aerogels from acidic aqueous solution and chitosan solution in Ionic Liquids (ILs). In addition, chitosan aerogels as drug delivery carriers are introduced in detail and expected to inspire readers to create new kind of drug delivery system based on chitosan aerogels. Finally, growing points and perspectives of chitosan aerogels in drug delivery system are given.