Abstract: Objective To observe the soft tissue regeneration after implantation of two novel citric acid-based biodegradable
materials in the skull defects in rats. Methods Two novel citric acid-based biodegradable materials were implanted in the
muscular tissues in the thigh and harvested 2 weeks later. Another 40 rats with surgically induced cranial defect were
randomized into control group, autograft group, CUPE-HA group, and POC-HA group (n=10), and 3 months after
implantation, the materials were harvested for histological and morphometric analyses. Results Soft tissue regeneration was
stimulated by the two biodegradable materials in the muscular tissues. The implants also stimulated angiogenesis and soft
tissue regeneration in the cranial defect and accelerated of intramembranous ossification. Conclusion The 2 novel citric
acid-based biodegradable materials can induce angiogenesis and soft tissue regeneration and accelerate intramembranous
ossification in rats with cranial defects.