Method of producing a microtube

A method of producing a microtube, the method comprising:

• co-electrospinning two polymeric solutions through co-axial capillaries to thereby produce the microtube, wherein a first polymeric solution of said two polymeric solutions is for forming a shell of the microtube and a second polymeric solution of said two polymeric solutions is for forming a coat over an internal surface of said shell, said first polymeric solution is selected solidifying faster than said second polymeric solution and a solvent of said second polymeric solution is selected incapable of dissolving said first polymeric solution, wherein a thickness of said shell is from about 100 nm to about 20 micrometer, and wherein an internal diameter of the microtube is from about 50 nm to about 50 micrometer.