Natural polysaccharide nanogels have remarkable research value and a great deal of potential to the treatment of cancer

due to the excellent advantages

including a wide range of sources

low price

good biocompatibility and biodegradability et al. Furthermore

the internal structure of the crosslinked network in it can effectively improve the stability of the drug. It can also be modified with some targeting ligands or environmentally sensitive groups making the deliver drug to reach the target tissues and cells successfully

leading to the controllable release of drugs and thus to improve efficacy and reduce side effects of drugs. Actually

the properties of these natural polysaccharide nanogels are different

so the comprehensive utilization of their advantage should be advocated. In this review

we focus on the natural polysaccharide nanogels served as a drug carrier for cancer treatment

mainly including the environment-responsive studies and targeted drug delivery of chitosan

dextran

pullulan

alginates

hyaluronic acid

heparin et al. Furthermore

the trends of natural polysaccharide nanogels and their application prospect in terms of cancer treatment were summarized at the end of this review. For example

the structure stability and biocompatibility of natural polysaccharide nanogels can be improved by co-polymerizing with synthetic macromolecule. Moreover

it is urgent to develop a size-controllable synthesis protocol to obtain natural polysaccharide nanogels

which may increase the drug loading capacity. Although a great many of studies on the natural polysaccharide nanogels for drug delivery system

some problem

such as how to improve the stimulus response speed

drug loading efficiency as well as targeted drug delivery still need to be solved. In the future

it is necessary to develop more flexible targeting ligands to decorate the natural polysaccharide nanogels for the specific recognition target tumor cells

as well as introduce some functional organic groups which are sensitive to pH or glutathione

such as disulfide bond

to obtain multiple response intelligent nanogels materials

achieving controlled drug release.