Oxidation-Sensitive Dextran-Based Polymer with Improved Processability through Stable Boronic Ester Groups.

Area of Science:

• Biomaterials Science
• Immunotherapy
• Polymer Chemistry

Background:

• Particulate immunotherapy uses nano/microparticles (MPs) to modulate immune responses for treating cancer, infectious diseases, and autoimmune disorders.
• The release rate of antigens from MPs influences the type and quality of the elicited immune response.
• Oxidation-sensitive drug delivery vehicles are desirable for effective immunotherapy, as cellular lysosomes are oxidizing environments.

Purpose of the Study:

• To develop a novel oxidation-sensitive aryl-boronate-modified dextran polymer for enhanced particulate immunotherapy.
• To overcome limitations of existing pinacol-based boronic esters, such as transesterification with biogenic diols.
• To create a stable, responsive material for controlled antigen release within antigen-presenting cells.

Main Methods:

• Synthesis of a pinanediol-based aryl-boronate-modified dextran polymer (PDB-Dex).
• Preparation of MPs using emulsion, nanoprecipitation, and electrospray techniques.
• Quantification of hydrogen peroxide-triggered degradation of MPs colorimetrically and mechanistic analysis using 1H NMR.

Main Results:

• The synthesized PDB-Dex forms highly stable boronic esters, unlike conventional pinacol-based materials.
• PDB-Dex exhibits tunable solubility, reversing water solubility while maintaining organic solvent solubility.
• Preliminary in vitro studies demonstrated low cytotoxicity and successful delivery of an immunostimulatory agent.

Conclusions:

• The novel PDB-Dex offers an improved, oxidation-sensitive platform for developing advanced particulate immunotherapy agents.
• This material addresses stability issues associated with previous boronic ester-based polymers.
• The PDB-Dex shows potential for controlled drug delivery and enhanced immune responses in therapeutic applications.