Engineering of an electrically charged hydrogel implanted into a traumatic brain injury model for stepwise neuronal tissue reconstruction.

Neural regeneration is extremely difficult to achieve. In traumatic brain injuries, the loss of brain parenchyma volume hinders neural regeneration. In this study, neuronal tissue engineering was performed by using electrically charged hydrogels composed of cationic and anionic monomers in a 1:1 ratio (C1A1 hydrogel), which served as an effective scaffold for the attachment of neural stem cells (NSCs). In the 3D environment of porous C1A1 hydrogels engineered by the cryogelation technique, NSCs differentiated into neuroglial cells. The C1A1 porous hydrogel was implanted into brain defects in a mouse traumatic damage model. The VEGF-immersed C1A1 porous hydrogel promoted host-derived vascular network formation together with the infiltration of macrophages/microglia and astrocytes into the gel. Furthermore, the stepwise transplantation of GFP-labeled NSCs supported differentiation towards glial and neuronal cells. Therefore, this two-step method for neural regeneration may become a new approach for therapeutic brain tissue reconstruction after brain damage in the future.

[Mediastinal Growing Teratoma Syndrome during Chemotherapy, Presenting as a Huge and Inoperable Tumor].

A 22-year-old male was diagnosed with a metastatic nonseminomatous germ cell tumor in the mediastinum with an elevated serum alpha-fetoprotein(AFP)concentration. Histopathological findings following percutaneous biopsy revealed the presence of a mature teratoma. Bleomycin, etoposide, and cisplatin(BEP)chemotherapy resulted decreased his serum AFP. However, the tumor became enlarged and was deemed inoperable due to size. Radiographic examination indicated diffuse calcification of the tumor mass. Growing teratoma syndrome in a patient with a primary mediastinal nonseminomatous germ cell tumor is extremely rare.