Injectable supramolecular polymer-nanoparticle hydrogels enhance human mesenchymal stem cell delivery

Area of Science:

• Regenerative Medicine
• Biomaterials Science
• Stem Cell Biology

Background:

• Stem cell therapies offer promise for treating injuries and diseases.
• Current delivery methods face challenges like invasive techniques and poor cell retention.
• Existing methods include bolus injections and cell-laden hydrogel implants.

Purpose of the Study:

• To design and evaluate an injectable polymer-nanoparticle (PNP) hydrogel for improved human mesenchymal stem cell (hMSC) delivery.
• To elucidate the mechanical properties of the hydrogel that enhance hMSC delivery.
• To demonstrate the efficacy of PNP hydrogels for *in vivo* hMSC retention.

Main Methods:

• Development of an injectable PNP hydrogel platform using modified biopolymers and biodegradable nanoparticles.
• Encapsulation and delivery of hMSCs within the PNP hydrogel.
• Characterization of fundamental hydrogel mechanical properties using *in vitro* models.
• *In vivo* studies in immunocompetent mice to assess hMSC retention.

Main Results:

• PNP hydrogels were successfully synthesized and demonstrated to encapsulate hMSCs.
• Fundamental hydrogel properties enhancing hMSC delivery were elucidated *in vitro*.
• *In vivo* studies showed enhanced hMSC retention at the injection site for up to 2 weeks.
• The PNP hydrogel system proved to be scalable, synthetic, and biodegradable.

Conclusions:

• The developed PNP hydrogel platform effectively overcomes limitations in current stem cell delivery methods.
• This novel hydrogel system enables enhanced and sustained local delivery of hMSCs.
• The findings support the potential of PNP hydrogels for advancing regenerative medicine therapies.