Advances in Chitosan Nanoparticles: A Comprehensive Review of Properties, Synthesis, Characterization, Multidisciplinary Applications, and Future Perspectives

Chitosan (chitin polymer) is a biocompatible polymer derived from the biodegradation of chitin, a non‐toxic biodegradable and polycationic polymer, with a high degree of usefulness that is typically associated with natural polymers. The combination of these unique characteristics, as well as their structural versatility, has made nanoscale formulations interesting. The properties of chitosan nanoparticles (ChNPs) are truly beneficial, such as controlling particle size, increasing surface functionality, and easy manipulation, which makes them one of the promising candidates in various scientific and industrial applications. In this review, basic characteristics of chitosan are thoroughly reviewed, and the potential uses of chitosan‐based manufactured nanomaterials have also been discussed. It also summarizes major fabrication processes of ChNPs: ionic gelation, microemulsion, cross‐linking, and plant‐extract‐assisted synthesis, which are some examples of fabrication processes by ultrasonication and spray drying. The main characterization methods applied in the morphology, stability, chemical structure, and functionality of ChNPs are also mentioned. A comparative examination of the ChNPs and other biopolymer‐based nanoparticles is provided in an attempt to explain the relative advantages and disadvantages. Medicine, agriculture, environmental engineering, and biotechnology are vital areas of discussion for the multidisciplinary applications of ChNPs in drug delivery, wound healing, water treatment, and in large‐scale farming.