Fibrous mats via electrospinning have been widely applied in tissue engineering. In this work, nanofibers were prepared via electrospinning from polymer with different content of carboxyl groups. A natural material, collagen, was then immobilized onto the nanofiber surface by N-(3-dimethylaminopropyl)-N'-ethylcarbodiimide hydrochloride (EDC)/N-Hydroxysuccinimide (NHS) activation process. It was found that the immobilization degree of collagen could be facilely modulated. The obtained collagen-modified nanofibers were used for neural stem cells culture, and unmodified nanofibers were used as a control. Results indicated that the modification of collagen could enhance the attachment and viability of the cultured neural stem cells.

In adult mammalian brain, vascular cells reside throughout life, close to central nervous system germinal zones, and neural stem cells (NSCs) mainly localize in the dentate gyrus of the hippocampus, subventricular zone, and olfactory bulb. Microvessels appear to produce a special microenvironment that may influence the characteristics of NSCs. To explore this potential correlation, an in vitro model with cocultured cerebral microvascular endothelial cells (CMECs) and NSCs was established in our study by using a transwell coculture system.

Transsphenoidal approach has been increasingly used in the resection of pituitary adenomas for its minimal invasiveness. However, in about 10% of these cases, the tumor cannot be totally removed due to the fibrosis. In this work, the object is to study the relationship between expression of transforming growth factor beta1 (TGFbeta1) and fibrosis of pituitary adenoma. 38 pituitary adenoma specimens were divided into fibrous group (6 cases) and non-fibrous group (32 cases). TGFbeta1 expression was detected by reverse transcript polymerase chain reaction (RT-PCR) and immunohistochemistry. Collagen content was detected by Sirius red stain. In fibrous group and non-fibrous group, respectively, (1) collagen content was 20.95% +/- 8.42% and 7.98% +/- 5.18%, with significant difference (p < 0.01); (2) TGFbeta1 mRNA was 0.79 +/- 0.15 and 0.42 +/- 0.20; TGFbeta1 protein was 0.64 +/- 0.20 and 0.32 +/- 0.40, both with significant difference (p < 0.01). Collagen deposition is a significant pathological feature in fibrous pituitary adenomas. TGFbeta1 may play an important role in the fibrosis of adenoma.

The pathological features of pituitary adenoma fibrosis are excessive collagen deposition. High expression of TIMP(1) may be an important cause.

In adult mammalian brain, microvessels may produce a special microenvironment and then influence the characteristics of neural stem cells (NSCs). This work aims to compare the effects of cerebral microvascular endothelial cells (CMECs) and vascular endothelial growth factor (VEGF) on the behaviors of NSCs. An in vitro model with co-cultured CMECs and NSCs was established by using transwell co-culture system. The expression of nestin and NF in the early stage of the co-culture, and NF in the later stage were explored by immunostaining. Results demonstrate that both CMECs and VEGF stimulate the proliferation of NSCs and inhibit the differentiation. After removing CMECs or VEGF from the co-culture system, a further culture in medium for the differentiation of NSCs was performed. The percentage of NF-positive cells in the CMECs co-culture group is the highest, suggesting the improved neuronal differentiation of NSCs by CMECs.