This is the 2D companion to the 3D ROS-responsive nanoparticle simulator, computed independently rather than a flattened render of the 3D scene. Both share the exact same physics -- but the 3D version's wound bed and nanoparticle cloud are already radially symmetric (a circular inflamed core, particles seeded uniformly across a disc), so this version exploits that symmetry directly: instead of stepping a 2D Cartesian grid, it solves the reaction-diffusion equation in one radial coordinate r, then plots the result as a genuine 2D-native diagram rather than a spatial top-down copy:
∂C/∂t = D·(∂²C/∂r² + (1/r)·∂C/∂r) + S(r) − λC
lim(r→0): ∂²C/∂r² + (1/r)∂C/∂r → 2·∂²C/∂r² (radial-symmetry limit at the core)
The top strip is a line/area chart of C(r) versus distance from the wound core -- a radial cross-section, not a disc. The bottom strip is a scatter/phase diagram: each nanoparticle's fixed radial distance rn against its own degraded fraction Dn, still driven by the same saturating Hill kinetics as the 3D model:
dD/dt = k · C(r_n)ⁿ/(Kdⁿ + C(r_n)ⁿ) · (1 − D), n = 2
Reading the two strips together answers the question the 3D disc view can only show indirectly: exactly how sharply does release fall off with distance from the inflamed core, and how does that sharpness change as you adjust diffusion range or sensitivity? A shallow C(r) curve (high diffusion) produces particles that trigger almost uniformly regardless of r; a steep one produces a hard cutoff visible directly as a cliff in the scatter plot.
- Intensity — how much ROS the inflamed core produces per second.
- Diffusion — how far the ROS signal spreads before decaying, i.e. how quickly C(r) falls off with r.
- Sensitivity (Kd) — the ROS concentration at which a particle is half-degraded.
- Dose — number of nanoparticles seeded across the wound bed radius.
Real-world relevance: this stimuli-responsive triggering strategy is used experimentally to deliver antimicrobials, antioxidants and growth factors selectively to inflamed wound tissue while sparing healthy skin.