Injectable Thermoresponsive Hydrogel For Sustained Drug Release and Enhanced Cell therapy
A reverse thermal gel based on a triblock copolymer (hydrophilic–polyurethane–hydrophilic) remains liquid below ~30 °C and rapidly forms a gel at physiological temperatures (35–40 °C). The central polyurethane or poly(ester urethane) segment can bear pendant or blocked active groups, while the outer hydrophilic blocks (PEG, hyaluronan or polycarbohydrates) confer water solubility and biocompatibility. This material sustainably encapsulates and releases therapeutic proteins (e.g., Avastin) over extended periods, degrades slowly in phosphate-buffered saline yet more rapidly in the presence of cholesterol esterase, and demonstrates excellent in vitro and in vivo tolerance. Functionalization with peptides such as IKVAVS produces a porous three-dimensional scaffold that fosters cell adhesion, migration, and neurite outgrowth. Moreover, the gel exhibits intrinsic antioxidant properties, protecting cells from reactive oxygen species and enabling minimally invasive delivery as an injectable liquid that solidifies in situ.
Description
What sets this technology apart is its unique combination of thermosensitive behavior, tunable degradation, and antioxidative support for transplanted cells. In a spinal cord injury model, co-administration with mesenchymal or Schwann cells increased cell survival fourfold without altering the macrophage response, leading to improved tissue sparing and motor recovery. Its versatile chemistry allows tailored functional groups and controlled drug release profiles, making it suitable for applications in nerve guidance, ocular delivery, and neural tissue engineering where both structural support and biochemical protection are critical.Applications
- Thermosensitive injectable cell scaffold- Controlled intraocular drug delivery
- Spinal cord injury repair
- Nerve guidance conduit scaffold
- Sustained protein therapeutics release
Advantages
- Thermoresponsive injectable sol-gel enabling minimally invasive in situ gelation at body temperature- Antioxidant properties that significantly enhance transplanted cell survival under oxidative stress
- Controlled, sustained release of therapeutic proteins and drugs (e.g., Avastin) over extended periods
- Excellent biocompatibility with tunable degradation rates in physiological and enzyme‐rich environments
- Functionalizable with bioactive peptides to promote cell adhesion, neurite outgrowth, and tissue regeneration
- Demonstrated improvement in spinal cord injury recovery and adaptable for intraocular delivery and nerve guidance scaffolds