Fat grafting based on 3D printed polyhydroxyalkanoate scaffolds

Area of Science:

• Biomaterials Science
• Tissue Engineering
• Regenerative Medicine

Background:

• Autologous fat grafting is promising for soft tissue repair but limited by poor graft retention and mechanical strength.
• Large-volume fat transplantation faces challenges with graft ischemia and hypoxia, impacting long-term outcomes.

Purpose of the Study:

• To investigate the efficacy of 3D-printed polyhydroxyalkanoate (PHA) scaffolds in enhancing fat graft retention.
• To elucidate the underlying mechanisms by which PHA scaffolds improve fat graft survival and integration.

Main Methods:

• Fabrication of 3D-printed biodegradable scaffolds using polyhydroxyalkanoates (PHA) containing 3-hydroxybutyrate and 4-hydroxybutyrate monomers.
• In vivo evaluation of scaffold effects on fat graft retention, angiogenesis, adipocyte viability, macrophage polarization, oxidative stress, and mitochondrial function.
• In vitro assessment of PHA biocompatibility and the effects of its degradation product, 3-hydroxybutyrate (3HB), on adipose-derived stem cells (ADSCs).

Main Results:

• 3D-printed PHA scaffolds significantly enhanced fat graft retention in vivo.
• Scaffolds promoted angiogenesis, improved adipocyte viability, induced M2 macrophage polarization, reduced oxidative stress, and optimized mitochondrial function.
• PHA scaffolds facilitated beige adipogenesis and white adipose tissue browning, further improving retention.
• In vitro studies confirmed PHA biocompatibility, with non-cytotoxic 3HB enhancing ADSC energy metabolism.

Conclusions:

• 3D-printed PHA scaffolds represent a viable strategy for improving fat graft retention in adipose tissue engineering.
• PHA scaffolds offer mechanical support and mitigate ischemia/hypoxia, promoting graft survival through multiple biological mechanisms.
• This study provides strong evidence for PHA scaffold application in soft tissue reconstruction and repair.