Gold nanoparticles in colon targeting

The colon is considered a promising location for drug delivery as colonic contents have a prolonged residence time and colonic mucosa facilitates drug absorption. This makes colon-targeted drug delivery systems useful in the treatment of a variety of local diseases like ulcerative colitis, Crohn's disease, irritable bowel syndrome, chronic pancreatitis, and colorectal cancer. Nanotechnology-based drug delivery systems offer multiple benefits in treating chronic ailments through site-specific delivery of drugs. Among various nanocarrier systems, metallic nanoparticles, especially gold nanoparticles (AuNPs), have gained popularity as they possess tunable optical and electronic properties, making them suitable for diagnosis, bioimaging, and therapy. AuNPs have been successfully conjugated with many functionalizing agents, like polymers, surfactants, ligands, dendrimers, drugs, DNA, RNA, proteins, peptides, and oligonucleotides. Utilizing AuNPs, especially in delivering drugs for treating CRC, is a promising strategy. This chapter summarizes the divergent characteristics of AuNPs, including their synthesis and recent applications in the diagnosis and treatment of various colonic diseases such as inflammatory bowel disease and colon cancers. This chapter also emphasizes the limitations and prospects of AuNPs in drug delivery.