Role of Cyclodextrins in Nanoparticle-Based Drug Delivery Systems

Cyclodextrins (CDs) are cyclic oligosaccharides with unique hydrophobic interior surfaces. Three parent CDs, α-CD, β-CD, and γ-CD, are further chemically modified primarily to make them suitable for parenteral administration, and these are used for many pharmaceutical applications. CDs offer distinctive advantages due to their unique ability to form inclusion complexes with a variety of organic and inorganic lipophilic molecules. This attribute is promising for a wide range of fields such as drug delivery, cancer therapy, gene delivery, and biosensing. In recent years, CDs have become more commonly used functional materials in nanoparticle (NP)-based drug delivery. The properties of NPs can be advantageously modified by the inclusion of CDs or their derivatives. CD-conjugated NPs (CD-NPs) have many benefits such as improved drug solubility and serve as drug carriers to specific locations such as cancer cells, which reduces toxicity to normal cells. In addition, CDs can overcome the limitations of NPs such as low encapsulation efficiency and drug loading. This review will discuss the various uses of CDs as it applies to NP-based drug carriers. Specifically, how CDs enhance the characteristics of polymeric, magnetic, lipid, metallic, and mesoporous NPs are discussed.