Advancing Drug Delivery Through Complex Physiological Barriers in the Brain, Lymph Node, and Placenta

Area of Science:

• Biomedical Engineering
• Pharmacology
• Neuroscience

Background:

• Physiological barriers like the blood-brain, blood-lymph node, and maternal-fetal interfaces impede drug delivery, leading to high failure rates for central nervous system-directed drug candidates.
• These barriers utilize tight junctions, efflux pumps, and immune surveillance to restrict the passage of both endogenous and exogenous substances, complicating disease treatment.

Purpose of the Study:

• To detail the microanatomy, transport mechanisms, and pathological changes of key physiological barriers.
• To benchmark emerging drug delivery technologies against current therapeutic strategies.
• To identify priority research questions for advancing drug delivery to the brain, lymph nodes, and placenta.

Main Methods:

• Review of microanatomy and transport mechanisms across blood-brain, blood-lymph node, and maternal-fetal barriers.
• Comparative analysis of emerging delivery vehicles (nanoparticles, responsive carriers, cell-mediated, bioderived) with existing therapeutics.
• Benchmarking against FDA-approved and experimental treatments.

Main Results:

• Significant disparities exist in the advancement of drug delivery techniques for the blood-brain barrier compared to lymph node and placental barriers.
• Emerging solutions show promise for overcoming physiological tissue barriers.
• Leveraging tissue-specific physiology is key to improving therapeutic outcomes.

Conclusions:

• Advancing drug delivery to challenging physiological barriers requires a deep understanding of tissue-specific physiology.
• Comparative analysis highlights the need for accelerated development in lymph node and placental drug delivery.
• Future research should focus on addressing identified priority questions to enhance therapeutic indices, reduce toxicity, and expedite clinical success.