Sustained delivery of vascular endothelial growth factor mediated by bioactive methacrylic anhydride hydrogel accelerates peripheral nerve regeneration after crush injury

Neurotrophic factors,currently administered orally or by intravenous drip or intramuscular injection,are the main method for the treatment of peripheral nerve crush injury.However,the low effective drug concentration arriving at the injury site results in unsatisfactory outcomes.Therefore,there is an urgent need for a treatment method that can increase the effective drug concentration in the injured area.In this study,we first fabricated a gelatin modified by methacrylic anhydride hydrogel and loaded it with vascular endothelial growth factor that allowed the controlled release of the neurotrophic factor.This modified gelatin exhibited good physical and chemical properties,biocompatibility and supported the adhesion and proliferation of RSC96 cells and human umbilical vein endothelial cells.When injected into the epineurium of crushed nerves,the composite hydrogel in the rat sciatic nerve crush injury model promoted nerve regeneration,functional recovery and vascularization.The results showed that the modified gelatin gave sustained delivery of vascular endothelial growth factors and accelerated the repair of crushed peripheral nerves.

Clinical management of primary odontogenic sarcoma in the mandible:a case report after WHO nomination

Ameloblastic fibro-odontosarcoma(AFOS)now designated as odontogenic sarcoma is an extremely rare odontogenic tumor,which histologically presents as a biphasic neoplasm with a malignant mesenchymal component plus ameloblastic epithelium.Here we report a 27-year-old Chinese female with the complaint of a painful swelling for half a month in the right mandible.A segmental mandibulectomy,with an immediate mandibular reconstruction using a free vascularized osteocutaneous fibular flap was performed using surgical guide models.Histological analysis revealed a primary odontogenic sarcoma.The postoperative period was uneventful,and no clinical indication of recurrence or metastasis was observed during the 3-year follow-up.No adjuvant therapy was proposed.This is the first odontogenic sarcoma case reported in China after the new World Health Organization classification of odontogenic lesions.