Thermosensitive Liposome Drug Release

Lipid Composition

Bath Temperature

Temperature T 37.0 °C

Transition cooperativity (width w) 2.0 °C

Simulation speed 1.0×

Live State

GEL (ORDERED)

Drug encapsulated

100.0%

Bilayer permeability

Elapsed release time

0.0 min

How it works

A liposome's phospholipid bilayer flips between an ordered gel phase and a disordered liquid-crystalline phase at a lipid-specific melting temperature T_m (DMPC ≈ 24°C, DPPC ≈ 41°C, DSPC ≈ 55°C). Near T_m, coexisting gel/fluid domains create transient packing defects at their grain boundaries, sharply raising membrane permeability — the basis of clinical thermosensitive liposomes (e.g. lysolipid-doped DPPC formulations) used to trigger drug release only inside a heated tumour.

Permeability is modelled as a cooperative (Boltzmann sigmoid) transition around T_m:

P(T) = 1 / (1 + exp(-(T - Tm) / w))

where w is the transition width (sharper for larger, more cooperative bilayers, i.e. smaller w). Drug efflux then follows first-order release kinetics with a permeability-scaled rate constant:

k(T) = k_max · P(T)
dN/dt = -k(T) · N(t)

N(t) is the amount of drug still encapsulated, integrated numerically each frame. Below T_m the bilayer stays tightly packed and release is slow; sweep the temperature slider through T_m and the release rate rises sharply, then saturates once the whole bilayer is fluid.

Lipid buttons — pick a phospholipid, which sets T_m and re-anchors the sigmoid.
Temperature — the bath/tissue temperature the liposome currently sits in.
Cooperativity (w) — how sharp the phase transition is; real bilayers with more lipid chains cooperating melt more abruptly (small w).
Simulation speed — scales elapsed simulated time per real second.

Encapsulated drug Released drug (diffusing)

⚠ Couldn't load the 3D engineThree.js failed to load from the CDN. Check your connection and reload.