Objective To investigate the cellular compatibil ity of polyvinyl alcohol (PVA)/wild antheraea pernyisilk fibroin (WSF), and to explore the feasibil ity for tendon tissue engineering scaffold in vitro. Methods The solutions of WSF (11%), PVA (11%), and PVA/WSF (11%) were prepared with 98% formic acid (mass fraction) at a mass ratio of 9 : 1. The electrospinning membranes of WSF, PVA, and PVA/WSF were prepared by electrostatic spinning apparatus. The morphologies of scaffolds were evaluated using scanning electronic microscope (SEM). The tendon cells were isolated from tail tendon of 3-dayold Sprague Dawley rats in vitro. The experiment was performed using the 3rd generation cells. The tendon cells (1 × 106/mL) were cocultured with PVA and PVA/WSF electrospinning film, respectively, and MTT test was used to assess the cell adhesion rate 4, 12 hours after coculture. The tendon cells were cultured in PVA and PVA/WSF extraction medium of different concentration (1, 1/2, and 1/4), respectively; and the absorbance (A) values were detected at 1, 3, 5, and 7 days to evaluate the cytotoxicity. The composite of tendon cells and the PVA or PVA/WSF scaffold were observed by HE staining at 7 days and characterized by SEM at 1,3, 5, and 7 days. Results The solution of WSF could not be used to electrospin; and the solution of PVA and PVA/WSF could be electrospun. After coculture of tendon and PVA or PVA/WSF electrospinning membranes, the cell adhesion rates were 26.9% ±0.4% and 87.0% ± 1.0%, respectively for 4 hours, showing significant difference (t=100.400, P=0.000); the cell adhesion rates were 35.2% ± 0.6% and 110.0% ± 1.7%, respectively for 12 hours, showing significant difference (t=42.500, P=0.000). The cytotoxicity of PVA/WSF was less significantly than that of PVA (P lt; 0.05) and significant difference was observed between 1/2 PVA and 1/4PVA (P lt; 0.05). HE staining and SEM images showed that the tendon cells could adhere to PVA and PVA/WSF scaffolds, but that the cells grew better in PVA/WSF scaffold than in PVA scaffold in vitro. Conclusion PVA/WSF electrospinning membrane scaffold has good cell compatibility, and it is expected to be an ideal scaffold of tendon tissue engineering.
Objective Poly (propylene carbonate) (PPC), a newly reported polymer, has good biodegradabil ity and biocompatibil ity. To explore the feasibil ity of using electrospinning PPC materials in nerve tissue engineering, and to observe the effect of al igned and random PPC materials on axonal growth of rat dorsal root gangl ions (DRGs) in vitro. Methods Either al igned or randomly oriented sub-micron scale polymeric fiber was prepared with an electrospinning process. DRGs were harvested from 3 newborn Sprague-Dawley rats (female or male, weighing 4-6 g), and were incubated into 12-pore plate containing either al igned (the experimental group, n=6) or randomly oriented sub-micron scale polymeric fiber (the control group, n=6). The DRGs growth was observed with an inverted microscope; at 7 days immunofluorescent staining and scanning electronic microscope (SEM) observation were performed to quantify the extent of neurite growth andSchwann cells (SCs) migration. Results Either al igned or random fibers were fabricated by an electrospinning process. The diameter of the individual fiber ranged between 800 nm and 1 200 nm. In al igned PPC material, 90% fibers arranged in long axis direction, but the fibers in random PPC material arranged in all directions. The DRGs grew well in 2 PPC materials. Onthe al igned fiber film, the majority of neurite growth and SCs migration from the DRGs extended unidirectionally, parallel to the al igned fibers; however, neurite growth and SCs migration on the random fiber films oriented randomly. The extents of neurite growth were (2 684.7 ± 994.8) μm on the al igned fiber film and (504.7 ± 52.8) μm on the random fiber films, showing significant difference (t= —5.360, P=0.000). The distances of SCs migration were (2 770.6 ± 978.4) μm on the al igned fiber film and (610.2 ± 56.3) μm on the random fiber films, showing significant difference (t= —5.400, P=0.000). The extent of neurite growth was fewer than the distances of SCs migration in 2 groups. Conclusion The orientation structure of sub-micron scalefibers determines the orientation and extent of DRGs neurite growth and SCs migration. Al igned electrospinning PPC fiber is proved to be a promising biomaterial for nerve regeneration.