ABSTRACT
Intracellular delivery of therapeutics is key for many applications.
The design of drug carriers capable of entering cells and trafficking
to precise intracellular destinations is an area of extensive research.
Many drug carriers exploit the endocytic route to gain intracellular
access, resulting in engulfment and transport within membrane-
bound endosomes. The cell-surface receptor or pathway targeted
often define the efficiency, kinetics, and final destination, which
can be also modulated by tuning carrier valency, surface charge,
geometry, composition, etc. Drug carriers contained in endosomes
can traffic to recycling routes, transcytosis across the cell body or,
most often, lysosomes. Lysosomal degradation of carriers allows for
drug release, needed in this compartment or at other sites within
the cell. Lysosomal escape may be required, for which carriers are
designed to detect lysosomal cues and disrupt the compartment. The
potential side effects of these endolysosomal interactions of drug
carriers are just beginning to be explored.
