Lecture 15 ‘Stealth’ particles.pdf

文档介绍：Molecular Principles of Biomaterials Spring 2003

Lecture 15: ‘Stealth’ particles



Last time: Nano- and micro-particle carriers


Today: Delivery of drugs to tissue from circulation
‘stealth’ particles theory and function

Reading: S. Stolnik et al. ‘Long circulating microparticulate drug carriers,’ Adv. Drug. Deliv. Rev.
16, 195 (1995)


Delivery of drugs to tissues via systemic circulation

Avenues of systemic molecule delivery

1. Intravenous injection
2. oral delivery to lumen of gut
Transcytosis:


objectives for systemic delivery to ans

ƒ avoid premature elimination by kidneys
o kidneys filter out molecules smaller than X nm
ƒ Avoiding reticuloendothelial system (RES)
o Particles larger than 200 nm screened by monocytes and macrophages in liver and spleen (Biochem.
Biophys. Res. Commun. 177, 861 (1991))
ƒ Kupffer cells – macrophages in liver
o Particulate removal aided by process of opsonization
ƒ Process of ‘tagging’ foreign particles for efficient removal by macrophages
Lecture 15 –‘stealth’ particles 1 of 8
Molecular Principles of Biomaterials Spring 2003

• Particles tagged by different opsonins removed by cells in ans . liver vs.
spleen
ƒ Components:
• Complement proteins, particularly C3 and C5
• Immunoglobulins
• Other proteins