Fully detachable molecular umbrellas as peptide delivery agents

Area of Science:

• Drug delivery systems
• Bioconjugation chemistry
• Lipid-based nanoparticles

Background:

• Developing targeted drug delivery systems is crucial for enhancing therapeutic efficacy and reducing side effects.
• Liposomes are versatile nanocarriers for drug delivery, but efficient encapsulation and release of active pharmaceutical ingredients remain challenges.
• Peptide-based therapeutics offer high specificity but often suffer from poor stability and bioavailability.

Purpose of the Study:

• To synthesize and characterize a novel persulfated molecular umbrella conjugate for peptide delivery.
• To investigate the release mechanism of the peptide from the conjugate in the presence of glutathione.
• To evaluate the ability of the conjugate to deliver a model peptide (DADLE) into liposomes.

Main Methods:

• Covalent attachment of a persulfated molecular umbrella (derived from cholic acid and spermidine) to DADLE using an o-dithiobenzyl carbamate linkage.
• Treatment of the conjugate with glutathione to induce peptide release.
• Preparation of glutathione-entrapped liposomes using POPC, POPG, and cholesterol.
• Incubation of the conjugate with the liposomes to assess peptide delivery into the aqueous interior.

Main Results:

• A stable conjugate (1) of the persulfated molecular umbrella and DADLE was successfully synthesized.
• Glutathione treatment effectively cleaved the o-dithiobenzyl carbamate linkage, liberating free DADLE.
• The conjugate demonstrated successful delivery of DADLE into the aqueous interior of glutathione-entrapped liposomes.

Conclusions:

• The persulfated molecular umbrella conjugate provides a viable strategy for the controlled release and delivery of peptides.
• The disulfide linkage is sensitive to glutathione, enabling triggered release of the payload.
• This approach shows promise for developing advanced liposomal drug delivery systems for peptide therapeutics.