Synthesis Lipopolymer

Synthesis of Lipopolymer by N-acylation of 2 kDa PEI with lipids chlorides.

1. Dissolve 100 mg PEI (2 kDa) in 5 mL of DCM Dichloromethane under N2 at room temperature.
2. Add 160 ÎŒL TEA Triethylamine.
3. Dissolve fatty acid in 5 mL of DCM.
4. Slowly add lipid to the PEI solution over a 30 min period.
5. Stir for 12 hrs under N2.
6. Stop the reaction by placing solution in ice bath.
7. Concentrate reaction mixture in vacuo
8. Wash 3 times with excess of ethyl ether.
9. Dry residue overnight under vacuum at room temperature.
C8: Caprylic Acid
C14: Myristic Acid
C16: Palmitic Acid
C18: Stearic Acid
C18:1: Oleic Acid
C18:2: Linoleic Acid

Synthesis Lipid-Substituted Polymers by N-acylation of PLL with activated fatty acid NHS-esters

Syntheis of NHS esters of fatty acids (NHS-X, were X= C8, C14, C16, C18, C18:1, C8:2)

1. Mix equal molar amounts of fatty acid, NHS, and DCC in dry ethyl acetate (12 mL).

2. Stir the reaction mixture overnight at room temperature under argon atmosphere.

3. Remove solid dicyclohexylurea by-product formed by filtration.

4. Concentrate the filtrate under reduced pressure.

5. Recrystallize the crude NHS-X in ethanol at 4 oC

1. Dissolve NHS-X in 1 mL of DMF and add dropwise to 15 mg of PLL in 1 mL of DMSO. (the fatty acid:PLL amine ratio is either 1:1.5 or 1:6).

2. Let react  24 h at room temperature under argon.

3. Add excess ethyl ether to  precipitate  the polymers, and then wash 3 times with ethyl ether.

4. Dry the polymers  under vacuum at ambient temperature overnight.