Table 1.

Synthesis methods used to make chitosan nanoparticles.

Methods	Process	Advantages	Disadvantages
Ionic gelation	Ionic cross-linking activated by mixing an aqueous solution containing chitosan and another containing TPP, thus resulting in a complex coacervate aqueous phase.	Straightforward procedure using mild chemicals. NP size easily regulated by altering the concentration of chitosan and TPP.	Difficult to produce uniformly sized NPs.
Microemulsion/reverse micelles	Based on covalent cross-linking where reverse micelle is formed upon introducing a surfactant into an organic solvent and then adding the mixture to an appropriate acidic solution containing chitosan.	Straightforward procedure achieving greater uniformity of size of NPs.	Use of harmful chemicals and a time intensive process.
Emulsification solvent diffusion method	Polymeric precipitation resulting in the formation of nanoparticles.	Straightforward procedure.	Substantial shear forces occur during the formation of CNPs.
Polyelectrol yte complex method	A self-assembly occuring due to the electrostatic interaction between the oppositely charged chitosan and the added polymer or counter ion, resulting in charge neutralization.	NP size can be regulated by pH of the solution, molecular weight (MW), and concentration of the constituents.	Due to the neutralization of charge, the PEC is self-assembled, leading to a substantial reduction in hydrophilicity.