Injectable biocompatible poly(2-oxazoline) hydrogels by strain promoted alkyne-azide cycloaddition

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Chemical Engineering

Background:

• Poly(2-alkyl-2-oxazoline) (PAOx) hydrogels possess tunable properties and biocompatibility for biomedical uses.
• Current PAOx hydrogels require invasive procedures for implantation due to their insoluble 3D networks.

Purpose of the Study:

• To develop an injectable PAOx hydrogel system using in situ gelation.
• To enable rapid gel formation under physiological conditions for biomedical applications.

Main Methods:

• Introduction of cyclooctyne and azide functional side chains onto PAOx copolymers.
• Induction of gelation via strain-promoted alkyne-azide cycloaddition upon mixing polymer solutions.
• Investigation of parameters like temperature, aqueous solutions, and stoichiometric ratios on hydrogel properties.
• Verification of in situ gel formation through subcutaneous injection into an ex vivo tissue model.

Main Results:

• Rapid gelation (within 5 minutes) achieved under physiological conditions.
• Demonstrated successful in situ gel formation within tissue samples.
• Degradation rates varied from days to a month, dependent on the media type.

Conclusions:

• Developed a novel method for creating injectable PAOx hydrogels via in situ gelation.
• The developed hydrogels show promise for injectable drug delivery systems and tissue engineering.
• Tunable degradation rates offer flexibility for various biomedical applications.