Table 2 Different types and main characteristics of controlled drug delivery systems for biomedical applications [141, 142]
Controlled drug delivery system | Material | Size | Structure | Types | Fabrication methods | Morphology |
|---|---|---|---|---|---|---|
Liposomes | Cholesterol Phospholipids | 20 nm–10 µm | Lipid based spherical shaped vesicular systems | Multilamellar Single compartment Macrovesicles | Solvent evaporation Solvent dispersion Reverse phase evaporation |
|
Micelles | Phosphatidyl ethanolamine, Phosphatidyl choline, PEG, PVP, PEOz, PEO, PCL, PLA… | 10–200 nm | Hydrophilic inner core–Hydrophobic shell architecture | Polymeric micelles Lipid micelles Supermicelles | Solvent evaporation Direct dilution Salting out Dialysis Flash nanoprecipitation |
|
Nanoparticles | PLGA, PEG, PCL, Chitosan, Cholesterol, Palmitate, Au, Si, Ag, Fe, Cu, Pb… | 10–300 nm | Nanocapsules, nanospheres, porus speheres | Polymeric Lipid Metal Gold/Silver Magnetic Silica | Solvent evaporation Double emulsion Homogenization Salting out NaBH4 reduction Sol–Gel synthesis |
|
Dendrimers | PAMAM, PPI | 20–400 nm | Macromolecules with a regularly branched tree-like structure | Simple, Chiral, Micellar, Hybrid, Metallo dendrimers | Divergent synthesis Convergent synthesis Self-assembly synthesis |
|
Carbon nanotubes | Carbon atoms | 0.5–50 nm Ø | Rolled sheets of graphene rings built from sp2 hybridized carbon atoms | SWCNTs, MWCNTs | Laser vaporization Chemical vapor deposition Arc discharge |
|
Hydrogels | Fibrin, collagen, hyaluronic acid, PEG, PVA, PAAM… | – | Natural/ synthetic cross-linked polymers containing a large amount of water | Temperature-responsive hydrogels, pH-responsive hydrogels, Electric-sensitive hydrogels, Ionic strength-sensitive hydrogels | Three-dimensional printing Layer-by-Layer fabrication Microfluidic-based fabrication |
|
Quantum dots | CdSe, CdS, ZnS, PbS… | 5–50 nm | Nanosized semiconductor particles with optical and electronic properties | Imaging QDs, Drug delivery QDs, Sensor applications QDs | Colloidal synthesis Plasma synthesis Self-assembled synthesis High temperature dual injection |
|
Polyelectrolyte complexes | Chitosan, PGA, SDS, CMCG, fibroin, SCMC… | 20–300 nm | Polymeric matrix with oppositely charged polyelectrolytes with strong but reversible electrostatic links | Nonstoichiometric water-soluble PECs, Stoichiometric insoluble PECs, Turbid colloidal stable PECs, Complex coacervates PECs | Solution spontaneous association Simple PECs titration technique |
|
