Table 1.

Summary of methods for microsphere fabrication.

Fabrication Methods	Materials	Advantages/Disadvantages	Size Range
Emulsification and solvent evaporation	PLGA [10], Chitosan [11], Gelatin [12], PCL/HA [13], Collagen [14], Collagen/chitosan [15]	Simple to operate Limited control over microsphere sizes	A few hundred nanometers to several millimeters
Spray drying	PLA [16], Chitosan [17], Alginate/HA [18]	Simple to operate Convenient to encapsulate bioactive molecules in microspheres Uncontrollable particle size and morphology	A few micrometers to several hundred micrometers
Phase separation	PLGA [19], Poly(l-glutamic acid)/chitosan [20], Chitosan [21]	Porous microspheres Effective for only a few polymers	A few micrometers to several millimeters
Microfluidics	PLGA [22], Bacterial cellulose [23], PCL [24]	Well controlled microsphere sizes Convenient drug loading Low productivity Time consuming	A few micrometers to several millimeters
Electrospray	PLGA [25], PLA [26], PCL/gelatin [27],	Simple to operate Uncontrollable particle size and morphology	A few micrometers to several hundred micrometers