In the last three decades, polymers have contributed significantly to the improvement of drug delivery technologies by enabling the controlled and sustained release of therapeutic agents, versatility in designing different delivery systems, and feasibility of encapsulation of both hydrophobic and hydrophilic molecules. Both natural and synthetic polymers have been explored for the delivery of various therapeutic agents. However, due to the disadvantages of synthetic polymers, such as lack of intrinsic biocompatibility and bioactivity, hydrophobicity, and expensive and complex procedure of synthesis, there is a move toward the use of naturally occurring polymers. The biopolymers are generally derived from either plants or microorganisms and have shown a wide range of applications in drug administration due to their hydrophilic nature, biodegradability, biocompatibility, no or low toxicity, abundance, and readily available, ease of chemical modification, etc. This review describes the applications of a biopolymer, xanthan gum (XG), in the delivery of various therapeutic agents such as drugs, genetic materials, proteins, and peptides. XG is a high molecular weight, microbial heteropolysaccharide and is produced as a fermented product of Gram-negative bacteria, Xanthomonas campestris. Traditionally, it has been used as a thickener in liquid formulations and an emulsion stabiliser. XG has several favourable properties for designing various forms of drug delivery systems. Furthermore, the structure of XG can be easily modified using different temperature and pH conditions. Therefore, XG and its derivatives have been explored for various applications in the food, pharmaceutical, and cosmetic industries.

The third most common cancer worldwide is colon cancer (CC). Every year, there more cases are reported, yet there are not enough effective treatments. This emphasizes the need for new drug delivery strategies to increase the success rate and reduce side effects. Recently, a lot of trials have been done for developing natural and synthetic medicines for CC, among which the nanoparticle-based approach is the most trending. Dendrimers are one of the most utilized nanomaterials that are accessible and offer several benefits in the chemotherapy-based treatment of CC by improving the stability, solubility, and bioavailability of drugs. They are highly branched polymers, making it simple to conjugate and encapsulate medicines. Dendrimers have nanoscale features that enable the differentiation of inherent metabolic disparities between cancer cells and healthy cells, enabling the passive targeting of CC. Moreover, dendrimer surfaces can be easily functionalized to improve the specificity and enable active targeting of colon cancer. Therefore, dendrimers can be explored as smart nanocarriers for CC chemotherapy.