Challenges and Limitations of the Lymphatic Drug Delivery Systems

The lymphatic system, the secondary vascular system in mammals, comprises lymph, vessels, nodes, and associated organs, playing vital roles in circulatory and immune functions and maintaining homeostasis through interstitial fluid removal. Drug delivery to the lymphatic system poses challenges for treating diseases like cancer metastasis. The physicochemical properties of nanoparticles, such as size, molecular weight, and surface properties, play a crucial role in lymphatic drug delivery, and significantly influence their interaction with the lymphatic system, impacting bioavailability and pharmacokinetics. Studies show that nanoparticles between 10 and 100 nm are ideal for lymphatic delivery, with smaller nanoparticles more likely to enter blood capillaries and larger ones absorbed through lymphatic vessels. Surface charge and hydrophilicity or hydrophobicity balance also affect the nanoparticle transport to lymph nodes. Challenges include overcoming size-related barriers and achieving optimal surface modifications for enhanced lymphatic uptake while ensuring stability during circulation. To summarize, this chapter will explore the challenges in delivering drugs to the lymphatic system, the physicochemical properties of the nanoparticles governing the drug delivery, lymphatic targeting, and different types of drug delivery systems used to target the lymph, along with their types, advantages, applications, and challenges.