Injectable, dual cross-linkable polyphosphazene blend hydrogels.

Area of Science:

• Biomaterials Science
• Polymer Chemistry
• Drug Delivery Systems

Background:

• Developing ideal injectable carriers faces challenges like harsh crosslinking conditions and limited tunability.
• Existing injectable systems often require external stimuli (e.g., UV light, heat) or toxic components.

Purpose of the Study:

• To design and synthesize a novel injectable, self-crosslinking, and thermosensitive polyphosphazene-based blending system.
• To overcome limitations of current injectable carriers by eliminating the need for external triggers or harsh chemicals.
• To create a versatile hydrogel system with tunable mechanical properties and degradation rates.

Main Methods:

• Synthesized functional thiolated and acrylated polyphosphazene polymers.
• Blended polymers to form aqueous solutions at low temperatures.
• Utilized thermosensitive hydrophobic interactions for gelation at body temperature.
• Facilitated in-situ chemical crosslinking between thiol and acrylate groups under physiological conditions.

Main Results:

• The polymer blends formed hydrogels at body temperature via thermosensitive hydrophobic interactions.
• In-situ crosslinking of thiol and acrylate groups enhanced mechanical strength.
• Tunable mechanical properties, network structure, and degradation rates were achieved by controlling crosslinking density.
• The system demonstrated inherent injectability, biodegradability, and thermosensitivity.

Conclusions:

• The developed self-crosslinking, thermosensitive polyphosphazene blend system is a promising injectable carrier.
• The system overcomes common barriers in injectable carrier development, offering improved mechanical properties.
• Tunable characteristics make these hydrogels suitable for various biomedical applications requiring injectable delivery systems.