Core Insights - The blood-brain barrier (BBB) presents significant challenges for delivering drugs to the central nervous system, particularly for neurodegenerative diseases and brain cancers [1][2] - Scientists are developing "shuttles" that can effectively transport biological drugs, such as antibodies and gene therapies, across the BBB [1][3] Group 1: Blood-Brain Barrier Challenges - The BBB acts as a protective barrier between the bloodstream and brain tissue, preventing harmful substances from entering the brain [2] - Small, lipophilic molecules can cross the BBB, but large biological drugs face significant obstacles, with less than 0.1% of certain antibody drugs reaching the brain after intravenous injection [2][3] - High doses of drugs are often required due to the low penetration rate, leading to potential waste and severe side effects [2] Group 2: Advances in Drug Delivery Technologies - Recent advancements in drug delivery systems are inspired by the brain's iron supply system, utilizing transferrin receptors to facilitate the transport of large molecules across the BBB [3][4] - Clinical projects are underway, with notable successes such as the enzyme replacement therapy for Hunter syndrome and the trontinemab antibody for Alzheimer's disease, which showed a threefold increase in amyloid clearance efficiency [3][4] - The range of deliverable "cargo" is expanding, including oligonucleotides for gene expression regulation and engineered viruses for gene therapy [4][5] Group 3: Future Prospects - The development of exosomes as natural "nanopackages" for delivering gene editing tools like CRISPR-Cas9 is gaining traction, indicating a promising future for brain-targeted therapies [5] - These innovative delivery technologies are expected to transform the medical landscape, offering new hope for patients with previously untreatable conditions [5]