Extrinsically controlled intracellular drug delivery

-A poem by Sarah MacEwan
Intrinsic targets in tumors may be
Receptors or enzymes or acidity
But intrinsic targets in tumors are tough
Some cancers and patients just don’t have enough
To deliver drug to sites of disease
Without side effects just wherever you please
Instead we can use an extrinsic cue
to gain some control from an external view
For this approach we can use ELPs
Reacting to heat with the slightest of ease
With careful design these can assemble
and spherical micelles they will resemble
This just occurs in conditions of heat
Without which as unimers they stay discrete
Add an internalization domain
Non-specific cell uptake this will obtain
How can we control this uptake you cry
Change the density from low levels to high
High density (micelles) - means uptake galore
low density (unimers) - uptake is poor
And there you have with a flip of a switch
A toggle from low to the density rich

Labeled with fluorophore ELPs glow
To see in the microscope or count with flow
Just in the presence of heat are they seen
Inside HeLa cell where they show up in green
Thus it is in vitro we can portray
That cell uptake can be controlled in this way
What we can propose to one day obtain
Is delivery control on in vivo terrain
Here we inject in a unimer state
where uptake remains at a diminished rate
If tumor alone is treated with heat
the micelle assembly will here be replete
Uptake is much greater here where it’s hot
Whereas normal cells uptake diddly-squat
Assembly targets the tumor you see
With the unheated healthy tissues left be
Thus tumor target we successfully meet
With an external trigger that is simply heat


See An Ode to Biopolymers for more poetry.