**Abstract**

In spite of good advancement for diagnosis and treatment, cancer is the second most common disease after cardiovascular disorders, may be responsible for maximum deaths in the world. Cancer is a leading cause of death worldwide, accounting for nearly 10 million deaths in 2020. Among cancers, colon or colorectal cancer is the second most common form of cancer globally with 916,000 deaths reported annually. Colon is the largest part of large intestine extending from ileocecal junction to anus. The delivery of drugs to the targeted site such as colon requires protection to the drug. As the most of the drugs are unstable in the gastric environment of the stomach and are susceptible to absorb in the upper gastrointestinal tract (GIT). This causes poor drug bioavailability and diminishes their efficacy against inflammatory bowel diseases (IBD). Thus, to deliver a drug to the targeted site such as colon via GIT requires protection from an undesirable release in the upper GIT to achieve maximal pharmacological effect, while administered orally. As a consequence, protection of drugs can be achieved by xylanbased hydrogel polymeric carriers, which are of non-toxic and biocompatible nature, and which can also undergo in-vivo biodegradation easily.

**Keywords:** xylan, hydrogels, polymer, colon cancer, targeted drugs delivery

## **1. Introduction**

Cancer is a leading cause of death worldwide, accounting for about 10 million in 2020. After lung cancer, colorectal cancer is the second most common form of cancer globally with 916,000 deaths reported annually [1]. Colorectal is a part of large intestine, extending from ileocecal junction to anus. The delivering of a drug to the targeted site for instance colon is a shattering problem as the most of the drugs have been reported to be unstable in the gastric environment of stomach and is more susceptible to absorb in the upper GIT. This causes diminished drug bioavailability and reduced their efficacy against inflammatory bowel disease (IBD). Thus drug delivery to the targeted site through GIT requires protection from an undesirable release in the upper GIT to achieve maximal pharmacological effect, while administered orally [2]. The protection of drugs can be achieved by using natural polymeric carrier-based hydrogels, such as xylan-based hydrogels, which are of non-cytotoxic [3], biocompatible nature, and which can also undergo in-vivo biodegradation easily. Hydrogels can

provide spatial and sequential control over the release of various therapeutic agents, including small-molecule drugs, macromolecular drugs, and cells [4]. On account of their tunable physical properties, controllable biodegradability and capability to protect labile drugs from degradation, hydrogels serve as a molecule in which various physiochemical interactions with the encapsulated drugs control their release. Therefore, by imparting designed functionality and providing appropriate treatments of xylan-rich hemicellulose by-products can effectively be used for targeted drug delivery via hydrogel preparation. Thus, the *aim of the present research is to focus on the isolation of xylans, their derivatizations, synthesis of hydrogels, and their applications*.
