Bioengineered vaults: self-assembling protein shell-lipophilic core nanoparticles for drug delivery

Area of Science:

• Biotechnology
• Nanotechnology
• Drug Delivery Systems

Background:

• Vaults are natural protein cages with potential for drug delivery.
• Existing drug delivery systems face challenges with lipophilic compounds.
• Hepatitis C virus nonstructural protein 5A (NS5A) can be engineered.

Purpose of the Study:

• To develop novel bioengineered vault nanoparticles for targeted drug delivery.
• To create a lipophilic microenvironment within vaults for encapsulating hydrophobic drugs.
• To evaluate the therapeutic potential of these nanoparticles for latent HIV treatment.

Main Methods:

• Recombinant vaults were engineered with an amphipathic α-helix from HCV NS5A.
• Electron microscopy was used to characterize vault structure and internal mass.
• Encapsulation and release of lipophilic drugs (all-trans retinoic acid, amphotericin B, bryostatin 1) were assessed.
• In vitro and in vivo studies evaluated the efficacy of bryostatin 1-loaded vaults in activating latent HIV.

Main Results:

• Engineered vaults exhibited increased internal mass due to lipid incorporation, creating a lipophilic core.
• Vault nanoparticles successfully encapsulated hundreds to thousands of drug molecules per particle.
• Bryostatin 1-loaded vaults demonstrated in vitro activation of HIV from latency.
• In vivo studies in mice showed CD69 biomarker expression after intravenous injection of bryostatin 1-loaded vaults.

Conclusions:

• Bioengineered vault nanoparticles offer a novel platform for reversible encapsulation of lipophilic drugs.
• These nanoparticles show significant potential as a drug delivery system, particularly for latent HIV therapy.
• The ability to control lipophilic compound delivery advances nanomedicine applications.