Thiomers--from bench to market.

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomedical Engineering

Background:

• Thiolated polymers (thiomers) are modified polymers with immobilized thiol groups.
• These modifications enhance mucoadhesive properties through disulfide bond formation with mucus glycoproteins.
• Thiomers offer additional benefits including enzyme inhibition and improved drug permeation.

Purpose of the Study:

• To explore the synthesis and properties of thiolated polymers.
• To investigate the advantages of thiolization for drug delivery applications.
• To highlight the potential of thiomers in various therapeutic areas.

Main Methods:

• Immobilization of thiol-bearing ligands onto polymer backbones (e.g., poly(acrylates), chitosans).
• Covalent attachment of mercaptonicotinamide substructures to further enhance properties and stability.
• Evaluation of mucoadhesion, enzyme inhibition, efflux-pump inhibition, and permeation enhancement.

Main Results:

• Thiolation significantly improves mucoadhesive properties compared to unmodified polymers.
• Disulfide bond formation is key to enhanced mucoadhesion.
• Further functionalization with mercaptonicotinamide improves properties and oxidative stability.
• Safety demonstrated in human volunteers and clinical trials for key thiomers.
• Industrial scale-up and GMP material availability for certain thiomers.

Conclusions:

• Thiolated polymers offer significant advantages for drug delivery, particularly in mucoadhesion and permeation.
• The development of thiomers is a rapidly advancing field with over 50 research groups involved.
• Clinical trials and product development indicate strong therapeutic potential, with the first product for dry eye syndrome entering the market.
• Further applications in areas like ocular surgery are under development.