THM-ESATT Nanomaterial Immunotoxicology & Safe-by-Design Desk
Portal / Methodology

Quantitative Methodology, BET Equations & Assay Rules

Delivered nanomaterial surface-area dose converts mass concentration (ug/mL) and nitrogen adsorption BET specific surface area (m2/g) into biological exposure area (cm2/mL) via a 0.01 scaling factor. Orthogonal endotoxin validation requires 50% to 150% spike recovery under ISO 29701 before scoring complement SC5b-9 or cytokine fold-changes across primary human donor cohorts.

Standards alignment: ISO 29701, NCI-NCL Assay Cascade, EU-NCL, and OECD WPMN.

1. BET Specific Surface-Area Dose Normalization

Mass-based dosing fails to predict comparative toxicity between bulk-like submicron particles (BET 20 to 50 m2/g) and atomically thin 2D graphene oxide sheets (BET 350 to 900 m2/g). To place disparate material classes on a common cellular interface metric, convert mass concentration C_mass (ug/mL) and dry-powder BET specific surface area SSA_BET (m2/g) into delivered surface area per culture volume:

Dose_SA (cm2/mL) = C_mass (ug/mL) * 1e-6 (g/ug) * SSA_BET (m2/g) * 1e4 (cm2/m2) = C_mass * SSA_BET * 0.01

For example, graphene oxide dosed at 25 ug/mL with a measured BET area of 420 m2/g delivers 105.00 cm2/mL, exceeding the 10.0 cm2/mL macrophage surface-area overload threshold by more than ten-fold. By contrast, a spherical PLGA nanoparticle at 15 ug/mL and 45 m2/g delivers 6.75 cm2/mL, remaining within the non-overload screening window.

2. Threshold Weights & Evidence Grading Matrix

Parameter Nominal Pass Window Elevated / Watch Trigger Critical / No-Go Trigger
Delivered BET Dose <= 10.0 cm2/mL 10.1 to 50.0 cm2/mL > 50.0 cm2/mL
ISO 29701 Spike Recovery 50% to 150% at 1:10 dilution 50% to 150% only at >= 1:100 < 50% or > 150%
Human Plasma SC5b-9 < 2.0x vehicle baseline 2.0x to 3.5x vehicle baseline > 3.5x (CARPA Positive)
ASTM F756 Hemolysis < 2.0% non-hemolytic 2.0% to 5.0% borderline > 5.0% hemolytic

3. Zero-Telemetry Workbench Execution Posture

All interactive calculations in the Endotoxin, CARPA & BET Dose Workbench and sub-page diagnostic panels run strictly client-side in vanilla ES modules. Proprietary formulation parameters entered by toxicologists are never transmitted to remote servers, persisted in browser storage, or logged into analytics payloads.