Receptor-Targeted Dual pH-Triggered Intracellular Protein Transfer

Area of Science:

• Biotechnology
• Drug Delivery
• Nanomedicine

Background:

• Protein therapeutics offer significant medical potential but face challenges in efficient intracellular delivery.
• Current delivery methods often lack specificity and can be hindered by biological barriers.

Purpose of the Study:

• To engineer an active-targeted, dual pH-responsive delivery system for enhanced intracellular protein delivery.
• To overcome limitations in tumor cell entry and endosomal escape for protein therapeutics.

Main Methods:

• Fabrication of a system using enhanced green fluorescent protein (eGFP) linked to a pH-labile traceless azidomethyl-methylmaleic anhydride (AzMMMan) linker.
• Functionalization with polyethylene glycol (PEG)-GE11 peptide for epidermal growth factor receptor targeting and melittin for endosomal escape.
• Utilized dibenzocyclooctyne-octa-arginine-cysteine (DBCO-R8C) for cell-penetrating peptide activity and charge reversal at pH 6.5.

Main Results:

• The system demonstrated enhanced cellular uptake via charge conversion at tumoral extracellular pH (6.5) and GE11-mediated targeting.
• Achieved successful endosomal release and nuclear localization of eGFP cargo.
• Showcased potential therapeutic relevance through delivery of cytochrome c to induce cancer cell apoptosis.

Conclusions:

• The developed multifunctional bioresponsive system represents a promising strategy for intracellular delivery of protein drugs.
• The system's design facilitates targeted delivery, enhanced cellular entry, and controlled release for therapeutic applications.