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.
Objective Neuron purification is essential to procedure of various nerve cell experimental research, however, at present there is few reports on the effect of various factors on neural axons during purification. To find out a simple method of neuron purification, and to investigate the influence factors of corresponding purification culture in dorsal root gangl ion (DRG) tissue culture on β3-tubul in positive axon. Methods The DRGs were obtained from the 3 days neonatal SD rat microscopically and were made into cell suspension. Then, the amount of attached DRG neurons and non neuronal cells in poly-D-lysine (PDL) group, PDL/Laminin (PDL/LN) group and collagen-I (Col I) group was observed from 10 to 100 minutes. Then, the extension and arborization of β3-tubul in positive axons were observed after 72 hours completely randomised DRG tissue culture for the research of the influences among culture substrates (PDL, PDL/LN, and Col I), FBS (0, 5%, and 10%), 5 fluorouracil (5-Fu, 0, 20, and 40 μmol/L), and cytrarabine (Ara-C, 0, 10, and 20 μmol/L). Results Adherent cells were observed instantly after inoculation by inverted phase contrast microscope and inverted fluoresence microscope; after cell suspension was removed, adherent growth of DRGn cells and non-DRGn cells were still seen. In PDL group, the amount of NSE negative cells was significantly higher than that of NSE positive cells at 10 and 30 minutes (P lt; 0.05); the amount of NSE positive cells was significantly higher than that of NSE negative cells at 80, 90 and 100 minutes (P lt; 0.05). In PDL/LN gruop, there was no significant difference (P gt; 0.05) in the amount of NSE negative cells and NSE positive cells at 10, 20, 30, 40, and 50 minutes; the amount of NSE positive cells was significantly higher (P lt; 0.05) than that of NSE negative cells at 60, 70, 80, 90, 100 minutes. In Col I group, the amount of NSE negative cells was higher than that of NSE positive cells at 10-40 minutes, but showing no significant difference (P gt; 0.05); the amount of NSE positive cells was significantly higher (P lt; 0.05) than that of NSE negative cells at 70-100 minutes. At 72 hours after DRG tissue culture, the best result of β3-tubul in positive axon extension and arborization was obtained when the substrate level was PDL/LN, and the average length of PDL/LN level was significantly larger than that of other two substrates (P lt; 0.05). The highest number of β3-tubul in positive axon distal end was obtained at 5% concentration level of FBS (P lt; 0.05), but showing no significant differences in β3-tubul in positive axon length among three levels (P gt; 0.05). Both the most of β3-tubul in positive axon distal ends and the longest β3-tubul in positive axon average length were obtained at 0 μmol/L concentration level of 5-Fu, showing significant differences between 0 μmol/L level and 20, 40 μmol/L levels (P lt; 0.05). A similar result of β3-tubul in positive axon distal end was got at the 0 μmol/L level and 10 μmol/L level of Ara-C, which was significantly higher than that of 20 μmol/L level (Plt; 0.05). Conclusion? A purified DRG neuron suspension for neuron culture could be obtained via PDL differential attachment for 30 minutes. When DRG neuron culture, neuron special medium, PDL/LN substrate and 10 μmol/L Ara-C are recommended in β3-tubul in positive axon research.