Physics / mechanism
Porous or structured solid matrices engineered to load, protect, and release therapeutic molecules at controlled rates. Release kinetics governed by diffusion (Fickian or anomalous), erosion (surface vs. bulk), or stimuli-response (pH, temperature, enzymatic cleavage). Key parameters: pore size distribution (2–200 nm), surface area (up to ~1000 m²/g for mesoporous silica), drug loading efficiency (5–40 wt%), and release half-life (hours to months). State of the art includes mesoporous silica nanoparticles (MSN), PLGA microspheres (~50–90% encapsulation efficiency), lipid nanoparticles (LNPs—dominant post-mRNA vaccine scale-up), and MOF-based carriers. Substrate geometry—films, fibers, particles, implants—sets route-of-administration constraints.
Competitive landscape
LNPs dominate injectable/nucleic-acid space; PLGA owns degradable implant and microsphere segments. Competing approaches: hydrogel depots (slower release, lower loading), polymer micelles (self-assembling, limited stability), exosome mimetics (biological, manufacturing bottleneck), and inorganic calcium phosphate carriers (orthopedic niche). MSNs compete on tunability but face regulatory uncertainty on long-term clearance.
Companies using
Connected ideas
Sources
Frontier (open questions)
- To be added.