143
6. Purify further the resulted BLG-NCA by three recrystallizations from dry ethyl acetate/hexane (1/5 v/v) under high
vacuum at −20 °C, leading to a 65% yield of the BLG-NCA
formation.
1. Dissolve the copolypeptides in a mixture of trifluoroacetic acid
and dichloromethane (TFA/DCM 1:1, v/v) containing a few
mL of anisole, for 1.5 h (see Note 6).
2. Distill TFA and DCM, and remove the low-molecular-weight
salts and reagents, using dialysis in aqueous HCl (pH = 5.0) (see
Note 7).
The reactions used for the synthesis of the hybrid triblock terpolymer PEO-b-PBLG-b-PLL are shown in Fig. 2.
1. Pump to dryness in the HV line the amino end monofunctional
PEO (1.0 g, 0.112 mmol of C-NH 2 groups) (see Note 8).
2. Distill purified benzene (100 mL) (see Note 9).
3. Distill off the solvent and leave the polymer to dry overnight.
4. Distill DMF (10 mL) to dissolve the polymer.
5. Filtrate the solution in an ampoule (see Note 10).
6. Pump in the high-vacuum line to dryness for 1 day, 1.27 g
BLG-NCA (4.86 mmol).
7. Dissolve the monomer in 20 mL of freshly distilled DMF (see
Note 11).
8. Rupture the glass magnet of the macroinitiator ampoule,
allowing the ring-opening polymerization of BLG-NCA to
occur under vigorous stirring for 2 days, with occasional
degassing.
9. Remove an aliquot of the solution after the completion of the
polymerization for characterization of the PEO-b-PBLG
diblock copolymer.
10. Finally, add via cannula 1.22 g (4.50 mmol) of Boc-L-lysineNCA solution in DMF (see Note 12).
11. Transfer the PEO-b-PBLG solution in the Ar/vacuum line,
and leave under vigorous stirring for 3 days, with occasional
degassing, ultimately yielding PEO-b-PBLG-b-PBocLL (see
Note 13).
12. In order to obtain the PEO-b-PBLG-b-PLL: Dissolve 2.95 g
of the terpolymer in 15 mL of DCM.
13. Add TFA (DCM/TFA = 1/1 (v/v), ca. 10% w/w polymer
concentration) and leave it to react for 3 h.
14. Distill off the excess organic acid along with the solvent in the
HV line.
3.3 Synthesis
of the Triblock
Copolypeptide
PLL-b-PBLG-d7-b-PLL
3.4 Synthesis
of the Novel Triblock
Copolypeptide
PEO-b-PBLG-b- PLL
Nanostructured Polymersomes for Controlled Drug Delivery
6. Purify further the resulted BLG-NCA by three recrystallizations from dry ethyl acetate/hexane (1/5 v/v) under high
vacuum at −20 °C, leading to a 65% yield of the BLG-NCA
formation.
1. Dissolve the copolypeptides in a mixture of trifluoroacetic acid
and dichloromethane (TFA/DCM 1:1, v/v) containing a few
mL of anisole, for 1.5 h (see Note 6).
2. Distill TFA and DCM, and remove the low-molecular-weight
salts and reagents, using dialysis in aqueous HCl (pH = 5.0) (see
Note 7).
The reactions used for the synthesis of the hybrid triblock terpolymer PEO-b-PBLG-b-PLL are shown in Fig. 2.
1. Pump to dryness in the HV line the amino end monofunctional
PEO (1.0 g, 0.112 mmol of C-NH 2 groups) (see Note 8).
2. Distill purified benzene (100 mL) (see Note 9).
3. Distill off the solvent and leave the polymer to dry overnight.
4. Distill DMF (10 mL) to dissolve the polymer.
5. Filtrate the solution in an ampoule (see Note 10).
6. Pump in the high-vacuum line to dryness for 1 day, 1.27 g
BLG-NCA (4.86 mmol).
7. Dissolve the monomer in 20 mL of freshly distilled DMF (see
Note 11).
8. Rupture the glass magnet of the macroinitiator ampoule,
allowing the ring-opening polymerization of BLG-NCA to
occur under vigorous stirring for 2 days, with occasional
degassing.
9. Remove an aliquot of the solution after the completion of the
polymerization for characterization of the PEO-b-PBLG
diblock copolymer.
10. Finally, add via cannula 1.22 g (4.50 mmol) of Boc-L-lysineNCA solution in DMF (see Note 12).
11. Transfer the PEO-b-PBLG solution in the Ar/vacuum line,
and leave under vigorous stirring for 3 days, with occasional
degassing, ultimately yielding PEO-b-PBLG-b-PBocLL (see
Note 13).
12. In order to obtain the PEO-b-PBLG-b-PLL: Dissolve 2.95 g
of the terpolymer in 15 mL of DCM.
13. Add TFA (DCM/TFA = 1/1 (v/v), ca. 10% w/w polymer
concentration) and leave it to react for 3 h.
14. Distill off the excess organic acid along with the solvent in the
HV line.
3.3 Synthesis
of the Triblock
Copolypeptide
PLL-b-PBLG-d7-b-PLL
3.4 Synthesis
of the Novel Triblock
Copolypeptide
PEO-b-PBLG-b- PLL
Nanostructured Polymersomes for Controlled Drug Delivery