An Elastin-Like Protein for Injectable Tissue-Like Network.

Protein-based tissue fillers are promising for adipose regeneration due to their biocompatibility and tunable properties. Inspired by elastin's structure, we designed a low-immunogenicity "multiple-domain-collective elastin-like" (MDCE) protein for injectable tissue-like networks. The MDCE protein was composed of thermal-responsive elastin-like peptides (disordered domains), polyalanine enrichment (functional ordered domains), and zwitterionic polypeptides (hydrophilic domains). This design endows the MDCE protein hydrogel with in situ injectability and antifouling properties, resulting in a tissue-like modulus-tunable filler formation in vivo without chemical cross-linkers and prevention of foreign body rejection. Adipose stem cells, encapsulated in the MDCE hydrogel, can maintain activity for at least ∼9 days (>80% survival rate). In a rat model of adipose tissue defect, a 3-month injection of MDCE hydrogel for efficiently filling adipose tissue presents superior stability and lower immunogenicity compared to the bovine-source elastin proteins. This work provides methods for tissue fillers and scaffolds, aiding medical regeneration, particularly facial rejuvenation.