Elastin based cell-laden injectable hydrogels with tunable gelation, mechanical and biodegradation properties

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Polymer Chemistry

Background:

• Injectable hydrogels derived from extracellular matrix proteins like elastin hold significant potential for biomedical applications.
• Existing elastin-based hydrogels often suffer from cytotoxicity, fixed gelation behavior, and insufficient mechanical strength, limiting their clinical utility.
• There is a critical need for advanced hydrogel systems that are cytocompatible, injectable, mechanically robust, and possess tunable properties for diverse tissue engineering applications.

Purpose of the Study:

• To engineer highly cytocompatible and injectable elastin-based hydrogels with adjustable gelation kinetics and enhanced mechanical properties.
• To develop structurally stable hydrogels suitable for load-bearing applications through covalent functionalization.
• To create a versatile platform for tissue engineering by integrating elastin with a thermoresponsive copolymer.

Main Methods:

• Synthesized a thermoresponsive copolymer, poly(N-isopropylacrylamide-co-polylactide-2-hydroxyethyl methacrylate-co-oligo(ethylene glycol)monomethyl ether methacrylate), functionalized with N-acryloxysuccinimide.
• Covalently conjugated the functionalized copolymer (PNPHO) with α-elastin in aqueous media to form elastin-co-PNPHO.
• Evaluated injectability, in situ gelation at 37°C, mechanical properties (compression moduli), structural stability, in vivo bioabsorbability, and cell viability/proliferation of the developed hydrogels.

Main Results:

• Elastin-co-PNPHO solutions demonstrated injectability through fine gauge needles and formed hydrogels in situ at 37°C without crosslinkers.
• Gelling time was tunable from 2-15 minutes by adjusting PNPHO content, and compression moduli ranged from 40-145 kPa, indicating superior mechanical strength.
• Hydrogels exhibited high stability in physiological environments (10 wt% mass loss in 30 days), in vivo bioabsorbability, and supported high cell viability (>80%) with increased proliferation.

Conclusions:

• The developed elastin-co-PNPHO hydrogels offer a promising combination of injectability, tunable gelation, mechanical robustness, structural stability, and cytocompatibility.
• These hydrogels are bioabsorbable in vivo due to polylactide cleavage, making them suitable for transient tissue regeneration applications.
• Elastin-co-PNPHO hydrogels represent a significant advancement for various tissue engineering applications requiring load-bearing and cell-supportive scaffolds.