Currently, cellulose is positioned as the most popular natural high-molecular biopolymer, the modification products of which are used to obtain materials such as composites, films, fibers, membranes, nanofibers, nanogels, hydrogels, etc., which are widely used in medicine: tissue engineering , as a drug delivery system; cell technology, as matrices for the immobilization of enzymes and biologically active substances, etc. The demand for biomedical materials based on cellulose is due to such unique properties as its biocompatibility with various tissues, non-toxicity, high crystallinity and mechanical strength, etc. The object of scientific research is esters - cellulose mesylates, obtained by the author of the project by chemical and electrochemical modification in methanesulfonic acid (MSA) solutions. The advantage of using methanesulfonic acid as a solvent and medium for modifying cellulose in comparison with toluenesulfonic acid is its low toxicity compared to other acids; biodegradability - in the natural environment, MSA is part of the cycle of organic sulfur circulation in nature and is destroyed with the formation of sulfur and carbon dioxides. It was found that the interaction of alcohol groups with the MSA molecules leads to the formation of esters - cellulose mesylates (MCC and NCC) and cellobiose. It is important to note that in the literature there are no scientific data on the modification of cellulose in MSA solutions. In this regard, this project proposes new methods of synthesis and study of the properties of biomedical materials based on cellulose mesylates and its derivatives.