Abstract
This review systematizes and critically summarizes current knowledge of microcrystalline cellulose as a multifunctional material with considerable potential for property tailoring. Particular attention is given to the diversity of cellulose feedstocks, ranging from conventional sources such as wood and cotton to alternative agro-industrial residues, including rice husk, bagasse, straw, cocoa bean shells, and recycled textile materials. The analysis is structured around the relationship between feedstock architecture, isolation conditions, and the resulting functional properties of MCC. Major MCC production routes are examined in detail, including conventional acid hydrolysis, organosolv processing, HCl gasphase degradation, and hydrothermal treatment. The available evidence demonstrates that the characteristics of the initial lignocellulosic matrix, together with processing conditions, govern the degree of polymerization, crystallinity index, cellulose polymorphism, and particle morphology, thereby influencing the sorption behavior and chemical reactivity of the resulting material. Particular emphasis is placed on targeted chemical and physical modification strategies, including oxidation, esterification, and graft polymerization, which provide additional opportunities to tailor MCC performance. These approaches broaden its potential use in pharmaceutical formulations for direct compression, biomedical systems such as hydrogels and wound dressings, environmental sorbents, and advanced biocomposites. The scientific significance of this review lies in consolidating the transition from the conventional perception of MCC as a passive filler toward its consideration as an engineered functional precursor whose properties can be deliberately tailored for specific applications.