Table 1.

List of top-down strategies for the creation of engineered biodegradable particles in certain drug delivery application.

Particle fabrication tools	Size range	Shape range	Biodegradable particle matrices.	Cargo
Microfluidic Particle Fabrication	3 µm –200 µm	Spheres, ellipsoids, cylinders, discs (T-junction or FFD) Non-spherical, defined by photomask (CFL or SFL)	Biodegradable polymers (PLGA, PEG-PLGA) Ref. 71–73; gelator. Ref. 74–78; acrylated PEG Ref. 79, 80	Doxorubicin, DNA, quantum dots, proteins
Photolithography	≥100 nm in thickness; ≥ 800 nm in lateral dimension	2D, non-spherical	Photocurable prepolymers only. Ref. 85–87	Living cells, proteins
PRINT and other micromolding methods	10 nm–200 µm	Worm, cylinder, etc. More complicated structure combining mechanical stretching	Biodegradable polymers, Ref. 97, 103, 104; pH sensitive, Ref. 44; reductively labile acrylates, Ref. 98; proteins, Ref. 99, 105.	Imaging agents, isRNA, DNA, anti-cancer drugs, proteins, antibodies