RAFT-Mediated 3D Printing of Polylactones/Itaconate Elastomers with Polypeptide Surface Functionalization

Area of Science:

• Polymer Chemistry
• Materials Science
• Biomaterials

Background:

• Reversible addition-fragmentation chain transfer (RAFT) polymerization is gaining traction in vat photopolymerization for advanced applications.
• Postprinting surface functionalization via RAFT agent reactivation is a key area of interest.

Purpose of the Study:

• To develop RAFT photopolymerizable resins with high renewable content using sustainable itaconate monomers.
• To create 3D-printable, flexible, and pH-responsive materials with potential for surface biofunctionalization.

Main Methods:

• Synthesis of RAFT photopolymerizable resins incorporating dimethyl/dibutyl itaconate and hydroxyethyl acrylate.
• Development of a 4-arm polyester cross-linker functionalized with itaconic acid.
• Utilizing digital light processing (DLP) for 3D printing and two-stage printing for surface functionalization.
• Characterization using photorheology, mechanical testing, AFM, and FTIR spectroscopy.

Main Results:

• Efficient polymerization and elastomeric properties were confirmed for the itaconate-based resins.
• 3D printing of flexible structures, including microneedles, was achieved.
• Printed objects exhibited pH-responsive 4D behavior due to pendant carboxylic acid groups.
• Successful surface biofunctionalization with polylysine was demonstrated, leading to antimicrobial activity and patterned functionalization.

Conclusions:

• Sustainable RAFT photopolymerizable resins were successfully developed, enabling 3D printing of flexible and 4D-responsive materials.
• The controlled nature of RAFT polymerization facilitates advanced surface modification strategies.
• The developed materials show promise for applications requiring antimicrobial surfaces and precise spatial functionalization.