Targeting a rare amyloidotic disease through rationally designed polymer conjugates

Area of Science:

• Polymer Therapeutics
• Drug Delivery Systems
• Rare Amyloidosis Treatment

Background:

• Familial Amyloidotic Polyneuropathy (FAP) is a rare inherited amyloidosis characterized by transthyretin (TTR) aggregate-induced cytotoxicity.
• A previously discovered RAGE-based peptide sequence can prevent TTR aggregate cytotoxicity.
• Clinical progression of this peptide for FAP treatment requires optimized delivery systems.

Purpose of the Study:

• To design, synthesize, and characterize polymer conjugates of a RAGE-based peptide for potential FAP treatment.
• To evaluate the physico-chemical properties and therapeutic activity of these novel polymer-peptide conjugates.
• To optimize the polymer-drug linker for enhanced stability and therapeutic efficiency.

Main Methods:

• Synthesis and comprehensive physico-chemical characterization of polymer conjugates using polyethylene glycol (PEG) as a carrier.
• Optimization of polymer-peptide linkers using biodegradable (disulphide) and non-biodegradable (amide) covalent bonds.
• In vitro and in vivo stability assessments, TTR binding affinity studies using Surface Plasmon Resonance (SPR), and cytotoxicity assays monitoring caspase-3 activation in Schwann cells.

Main Results:

• The synthesized polymer conjugates retained the RAGE peptide's activity in reducing TTR aggregate cytotoxicity.
• Conjugation improved plasma stability compared to the free peptide.
• Non-biodegradable amide linkers demonstrated superior stability, indicating their necessity for therapeutic efficacy.

Conclusions:

• Polymer conjugation of RAGE-based peptides is a viable strategy for developing FAP therapeutics.
• Stable, non-biodegradable polymer-peptide linkers are crucial for ensuring therapeutic efficiency in treating TTR amyloidosis.
• These findings support the advancement of polymer therapeutics for rare amyloid diseases.