20
5. Wash the solid residue obtained on top of the PTFE filter with
THF and dichloromethane (50 mL) to remove any physisorbed drug/biomolecule (see Note 11).
6. Recover the drug/biomolecule-functionalized CNHs as powder and store it at room temperature in the dark.
1. Treat pristine CNHs (50 mg) in oxygen gas at 570–580 °C for
15 min to create holes on their walls. Then, heat the oxidized
material at 1200° C under hydrogen atmosphere to remove the
oxygen functionalities attached to the hole edges (see Note 12).
2. Dissolve the drug/biomolecule (400 mg) in DMF (100 mL)
in a glass container and add the as-prepared meshed CNHs
(50 mg). Bath-sonicate the mixture for 30 min. Subject the
mixture to slow evaporation of the DMF with the aid of dry
air over 5 s (see Note 13).
3. Collect the black material (CNHs filled with the drug/biomolecule) from the bottom of the container.
4. Wash the obtained CNHs filled with the drug/biomolecule
on top of a PTFE membrane filter with DMF and dichloromethane (50 mL) to remove any physisorbed drug/biomolecule (see Note 14).
5. Recover the drug/biomolecule encapsulated within CNH
material as powder and store it at room temperature in the dark.
4 Notes
1. Bath sonication allows dispersion of insoluble CNHs and facilitates reaction. Add the solvent in small portions to wet the
solid. CNH is a very light powder; thus fast incorporation of
the solvent may produce airstream inside the flask pushing the
light powder out.
2. The BOC-protected aniline derivative, namely tert-butyl
2-(2-(2-(4-aminobenzamido)ethoxy)ethoxy) ethylcarbamate,
is prepared according to the following procedure: a solution of
p-nitrobenzoyl chloride (464 mg, 2.5 mmol) in DCM (30 mL)
was added to a cold solution (ice bath) of tert-butyl
2-(2-(2-aminoethoxy)ethoxy)ethylcarbamate
(500 mg,
2.0 mmol) in 0.2 N NaOH solution (50 mL). The reaction
mixture was stirred vigorously at 0° C for 3 h. The organic
layer was then separated, washed successively with 0.5 N
NaOH and water and then dried over anhydrous Na 2 SO 4 .
Evaporation of the solvent under reduced pressure affords the
nitro-derivative as a white solid with 85% yield. The aforementioned nitro-derivative (170 mg, 0.427 mmol) was dissolved
in dry ethanol (20 mL) and Pt/C 10 wt% (18 mg) was added.
3.6 Encapsulation
of Drugs/Biomolecules
Within CNHs
Anastasios Stergiou and Nikos Tagmatarchis
5. Wash the solid residue obtained on top of the PTFE filter with
THF and dichloromethane (50 mL) to remove any physisorbed drug/biomolecule (see Note 11).
6. Recover the drug/biomolecule-functionalized CNHs as powder and store it at room temperature in the dark.
1. Treat pristine CNHs (50 mg) in oxygen gas at 570–580 °C for
15 min to create holes on their walls. Then, heat the oxidized
material at 1200° C under hydrogen atmosphere to remove the
oxygen functionalities attached to the hole edges (see Note 12).
2. Dissolve the drug/biomolecule (400 mg) in DMF (100 mL)
in a glass container and add the as-prepared meshed CNHs
(50 mg). Bath-sonicate the mixture for 30 min. Subject the
mixture to slow evaporation of the DMF with the aid of dry
air over 5 s (see Note 13).
3. Collect the black material (CNHs filled with the drug/biomolecule) from the bottom of the container.
4. Wash the obtained CNHs filled with the drug/biomolecule
on top of a PTFE membrane filter with DMF and dichloromethane (50 mL) to remove any physisorbed drug/biomolecule (see Note 14).
5. Recover the drug/biomolecule encapsulated within CNH
material as powder and store it at room temperature in the dark.
4 Notes
1. Bath sonication allows dispersion of insoluble CNHs and facilitates reaction. Add the solvent in small portions to wet the
solid. CNH is a very light powder; thus fast incorporation of
the solvent may produce airstream inside the flask pushing the
light powder out.
2. The BOC-protected aniline derivative, namely tert-butyl
2-(2-(2-(4-aminobenzamido)ethoxy)ethoxy) ethylcarbamate,
is prepared according to the following procedure: a solution of
p-nitrobenzoyl chloride (464 mg, 2.5 mmol) in DCM (30 mL)
was added to a cold solution (ice bath) of tert-butyl
2-(2-(2-aminoethoxy)ethoxy)ethylcarbamate
(500 mg,
2.0 mmol) in 0.2 N NaOH solution (50 mL). The reaction
mixture was stirred vigorously at 0° C for 3 h. The organic
layer was then separated, washed successively with 0.5 N
NaOH and water and then dried over anhydrous Na 2 SO 4 .
Evaporation of the solvent under reduced pressure affords the
nitro-derivative as a white solid with 85% yield. The aforementioned nitro-derivative (170 mg, 0.427 mmol) was dissolved
in dry ethanol (20 mL) and Pt/C 10 wt% (18 mg) was added.
3.6 Encapsulation
of Drugs/Biomolecules
Within CNHs
Anastasios Stergiou and Nikos Tagmatarchis