Biodegradable carrier with adjustable zeta potentials and particle sizes, method for making the same, and pharmaceutical composition comprising the same

A method for making a biodegradable carrier with adjustable zeta potentials and particle sizes comprising the steps of:

• preparing a first solution comprising a first biodegradable macromolecule with a first electric property;
• preparing a second solution comprising a second biodegradable macromolecule with a second electric property according to a desired zeta potential of a biodegradable carrier and adding the second solution into the first solution to form a mixture solution, wherein the first electric property is opposite to the second electric property for making the biodegradable carrier with the desired zeta potential by attraction force between the different electric properties;
• proportionally adjusting the mole number of the first biodegradable macromolecule and the second biodegradable macromolecule in the mixture solution according to a desired particle size of the biodegradable carrier, wherein the particle size of the biodegradable carrier is positively correlated with the mole number of a solute in the mixture solution for making the biodegradable carrier with the desired particle size;
• and
• filtrating the mixture solution after the proportionally adjusting step to obtain the biodegradable carrier.