The nerve tissue engineering (NTE) has been applied in the treatment of central nerve system injury or disease to restore its anatomic structure and function, in which the nervous scaffolds played important roles in supporting and nourishing the nerve tissues. Development, challenge confronted and foreground of research on scaffolds material in the nerve tissue engineering are reviewed in this article.

Background Integrated transepithelial photorefractive keratectomy (TransPRK) is a new kind of surface ablation and has a fast reepithelialization and uncorrective visual acuity (UCVA) recovery as well as slighter postoperative pain,and epipolis laser in situ keratomileusis (Epi-LASIK) has been recognized to be an effective method for myopia.But there have been few studies to evaluate the dynamic change of the corneal biomechanical properties and posterior corneal elevation after TransPRK.Objective This study was to assess and compare the effectiveness and safety between TransPRK and Epi-LASIK for myopia with thin cornea.MethodsThis study was approved by Ethic Committee of Jinan Mingshui Eye Hospital,and written informed consent was obtained from each patient.In this prospective non-randomized controlled study,93 right eyes of 93 myopic patients with the central corneal thickness 460 to 500 μm were included in Jinan Mingshui Eye Hospital from June to December 2013 under the informed consent.The eyes were divided into TransPRK group for 46 eyes and Epi-LASIK group for 47 eyes.UCVA,manifest refraction,haze,corneal biomechanical properties,posterior corneal elevation,Qvalue and corneal high order wavefront aberration were analyzed before and 1 week,1 month,3 months and 6 months after operation,respectively,and the examination results were compared between the two groups.Results There was no statistically significant difference in the eyes of postoperative UCVA and manifest refraction between the TransPRK group and the Epi-LASIK group at various time points (all at P＞0.05).Six months after surgery,the percentage of eyes with UCVA of 1.0 or better was 93.9％,and 90.9％ eyes exhibited the targeted refraction in ± 1.00 D in the TransPRK group.Corneal haze was most obvious 1 month after surgery in both groups,with the incidence of 32.6％ (15/46) in the TransPRK group and 17.4％ (8/47) in the Epi-LASIK group,but no significant difference was found in the eye numbers with haze between the two groups (x2 =2.841,P =0.092).No significant differences were seen in the corneal hysteresis(CH) values and corneal resistance factor(CRF) values between the two groups (CH:Fgroup =0.000,P =0.999;CRF:Fgroup =0.110,P =0.741),however,the postoperative CH values and CRF values were significantly declined in comparison with preoperative ones,with significant differences among various time points (CH:Ftime =103.658,P =0.000;CRF:Ftime =132.008,P =0.000),while there were no remarkable differences between any two time points in postoperation (all at P＞0.05).Posterior corneal surface height shifted rearward 1 week,1 month,3 months and 6 months after surgery,showing remarkable differences in comparison with before surgery in both groups (Ftime =12.868,P =0.001),but no significant differences between the two groups (Fgroup =1.923,P=0.169).No significant differences were found in Q-value between the two groups (Fgroup =0.191,P=0.663).Root mean square (RMS) and spherical aberration values elevated in postoperation compared with preoperation,with significant differences between them(all at P＜0.01),but the comparison between intergroup was insignificant (RMS:Fgroup =0.299,P =0.586;Spherical aberration:Fgroup =1.290,P =0.259).Conclusions TransPRK for myopia with thin cornea is safe and stably effective like Epi-LASIK.TransPRK affects corneal biomecbanical properties early after surgery but the effect gradually lessens over time.The posterior corneal elevation shows a tiny backward displacement,while posterior corneal asphericity has no change.

BACKGROUND:IKVAV-containing peptide sequence is an active region that promotes the adhesion, growth, and differentiation of neural cells in the laminin. It can be fabricated into a novel tissue-engineered scaffold material by self-assembly into hydrogel.OBJECTIVE: This study was designed to synthesize IKVAV-containing (C16H31O-AAAA GGGEIKVAV) peptide. The peptide was observed self-assembly into three-dimensional and porous hydrogel after triggered with phosphate buffered saline (PBS).DESIGN, TIME AND SETTING: Single-sample experiment, performed in the Laboratory of Department of Orthopedics,Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology between September 2004 and January 2005.MATERIALS: IKVAV-containing peptide was synthesized by solid phase method.METHODS: Peptide purity and relative molecular mass were detected by high performance liquid chromatogram and mass-spectrometry, respectively. 1% peptide, whose pH value was equal to 9.5, was self-assembled into hydrogel with the addition of PBS. The ultramicrostructure of the hydrogei was observed through the use of transmission electron microscope (TEM).MAIN OUTCOME MEASURES: Peptide purity and relative molecular mass were detected. Moreover, gross observation of the peptide after self-assembly and TEM observation of peptide ultramicrostructure were performed.RESULTS: Peptide relative molecular mass was 1351.6, which was in accordance with its theoretical value. Peptide purity was 95%. After triggered with PBS, 1% peptide was self-supported into hydrogel in a few seconds. TEM results showed that self-assembled hydrogel consisted of the interconnected nanofibers which varied from 3 to 6 nm in diameter and 100 to 1 500 nm m in length.CONCLUSION: The IKVAV-containing peptide was synthesized and self-organized successfully into porous hydrogel,which was triggered with PBS solution.

Objective To probe the effect of applying montelukast combined with pidotimod in asthma of aged patient.Methods 120 cases of asthma in non-acute episode phase were randomly divided into three groups.Group 1 was treated with montelukast combined with pidotimod,group 2 was treated with montelukast,and the control,namely group 3 was ketotifen.All cases were treated by means of intensification therapy including glucocorticoids,?_2 agonists and some necessary anti-infection during acute episode.Results After 10 weeks treatment,both group 1 and 2 made notable improvement with respect to many asthma control parameters(P

Objective To evaluate the predictability of ablated depth in photorefractive procedures by Zeiss MEL80 and VISX Star S4 excimer laser.Design Prospective,comparative case series.Participants 168 eyes of 84 people with myopia and cylinder.Main Outcome Measures Corneal thickness and ablated depth.Methods The thickness of cornea by Zeiss MEL80 and VISX Star S4 were measured by anterior segment OCT.The actuality ablated depth and calculated depth were compared.Results There were no significant differences between actuality ablated depth and calculated depth in Zeiss MEL80.And in VISX Star S4,the actuality ablated depth was more than calculated depth.Linear regression of changes in ablated depth on myopia and cylinder yielded the following formulaus:△ablated depth(VISX Star S4)= 2.324 *|myopia|+ 5.270 *|cylinder|-6.772.Conclusions Different excimer laser has different changes between actuality ablated depth and calculated depth.To guarantee the safety of LASIK,Ophthalmologists should know the characteristics of the excimer laser.

The RGD-containing peptide was used to modify the surface of porous PLGA-[ASP-PEG], and was incubated in the modified simulated body fluid (mSBF) for two weeks. The mineralization of PLGA-[ASP-PEG] was explored. The active peptide was used to modify PLGA-[ASP-PEG] through cross-linker (Sulfo-LC-SPDP), characterized by X-ray photoelectron spectroscopy (XPS) the peptide-modified PLGA-[ASP-PEG] (Experiment group, EG) and PLGA-[ASP-PEG] without modification (Control group, CG) were all incubated in mSBF for two weeks, confirmed by observation of Scanning electron microscope(SEM) and measurements of Energy dispersive analysis system of X-ray (EDS) and X-ray diffractometry (XRD). XPS indicated that the binding energy of sulphur in EG was 164eV, and the ratio of carbon to sulphur in EG was 99.746 : 0.1014, however, sulphur was not detected in CG; SEM analysis demonstrated that the mineralization layers were more consecutive and compact in EG than in CG. The results of EDS and XRD indicated that the main component of mineral was hydroxyapatite, and the ratio of Ca/P was 1.60 in EG, and 1.52 in CG. RGD-containing peptide provided enough functional groups for mineralization; the mineralized peptide- modified PLGA-[ASP-PEG] possessed the bonelike microstructure.
Biocompatible Materials ; chemistry ; Bone Substitutes ; Bone and Bones ; metabolism ; Calcification, Physiologic ; Lactic Acid ; chemistry ; Oligopeptides ; chemistry ; Osteogenesis ; drug effects ; Peptides ; chemical synthesis ; pharmacology ; Polyglycolic Acid ; chemistry ; Surface Properties

The amphiphilic polypeptide (PA) was self-assembled into three-dimensional (3-D) porous complex of hydrogel and cells with the addition of NSCs-containing DMEM/F12. Cell differentiation in the surface and that within hydrogel were described. Cells harvested from the cerebral cortex of neonatal mice were triturated and cultivated in serum-free media. 1wt% PA was added into same volume of DMEM/F12 with cell concentration of 1 x 10(5)/ml and self-supported into 3-D hydrogel-cell composition; cells suspended within hydrogel being maintained (Experiment group, EG). lwt% PA was self-assembled into two-dimensional (2-D) hydrogel films triggered by addition of DMEM/F12, and then 1 x 10(5)/ml NSCs was seeded in the surface of films (Control group, CG). Cells in EG and CG were incubated in serum-free media for two weeks and stained with immunocytochemistry methods. TEM showed that the hydrogel derived from PA was composed of network nanofibers with their diameter ranging from 3 to 5 nm and length ranging from 100 nm to 1. 5 microm. Above 50% of cells obtained were Nestin positive cells. LSCM observations demonstrated that above 90% of cells survived two days after incubation within hydrogel, and were differentiated into NF and GFAP positive cells one week after incubation, their differentiation rates were 50% +/- 4.2% and 20% +/- 2.8% respectively; however, cells in CG were also differentiated into NF and GFAP positive cells, their differentiation rates were only 40% +/- 3.4% and 31% +/- 2.3% separately. Peptide-based hydrogel was able to provide 3-D environments for cell survival and induce primarily the differentiation of NSCs into neurons. Our data indicated that peptide-directed self-assembly of hydrogels was useful and it served as the neotype nerve tissue engineering scaffolds.
Animals ; Animals, Newborn ; Cell Culture Techniques ; Cell Differentiation ; drug effects ; Cells, Cultured ; Hydrogel, Polyethylene Glycol Dimethacrylate ; chemistry ; metabolism ; Nanofibers ; chemistry ; Neural Stem Cells ; cytology ; Neurogenesis ; drug effects ; Peptides ; chemistry ; metabolism ; Rats ; Rats, Sprague-Dawley ; Tissue Scaffolds ; chemistry

Objective To explore the effects of surface modification of PLGA-[ASP-PEG] scaffold with typeⅠcollagen on the adhesion,proliferation and osteogenic differentiation of rabbit bone marrow stromal cells (BMSCs).Methods After PLGA-[ASP-PEG] materials were modified with typeⅠcollagen chemically,the collagen was coated onto the materials physically.The BMSCs obtained from rabbits were cultured on the modified PLGA-[ ASP-PEG] and on the unmodified PLGA-[ ASP-PEG] as control.The adhesion and proliferation behavior of the cells was analyzed and the expressions of osteogenie marker alkaline phosphatase,osteocalcin,osteopontin,typeⅠcollagen and core binding factor al were also detected.Results X-ray photoelectron spectrometry(XPS) confirmed that TypeⅠcollagen was grafted onto the surface of PLGA-[ASP-PEG] successfully and the collagen content on the materials modified chemically and physically was significantly increased.The abilities of adhesion and proliferation and the expressions of osteogenie makers of the BMSCs were significantly greater than those in the control group(P＜0.05).Conclusion Since Type collagen I can improve the biocompatibility of PLGA- [ASP-PEG] scaffold materials,it can be used as a new way to optimize scaffolds in tissue engineering.

Objective To investigate the clinical value of iPass in three dimensional contrast enhanced MR angiography (3D-CE-MRA). Methods iPass were performed in 32 cases, including cervical vessel (4 cases), pulmonary vessel (7 cases), abdominal vessel (18 cases), and femoral vessel (3 cases). iPass bolus tracking was run before 3D-CE-MRA. The tracking sequence was operated repeatedly with real time display of image. The peak of bolus arrival time(Tp), identified with signal of target vessel increased 30% over baseline, was automatically loaded in the timing page of 3D-CE-MRA, and the time of scan delay(Td) was computed by the system with Tp. The acquired images were subtracted and reconstructed by MIP. The quality of MIP image was evaluated. Results The iPass bolus tracking sequence and 3D-CE-MRA were completed successfully in 29 cases. The bolus tracking couldn′t detect the bolus arrival time in 3 cases, but they were completed through changing ROI and bolus tracking repeatedly. The average score of 3D-CE-MRA MIP image was 3.81?0.59. Conclusion iPass can provide the exact Tp and automatically control Td of 3D-CE-MRA. iPass is a useful procedure to improve the image quality and provide the specific scanning scheme for 3D-CE-MRA.

Objective:To investigate the best preservation conditions of N-terminal pro-brain natriuretic peptide( NT-proBNP) and provide detection references with stable performance for detection kits.Methods: ELISA was used to quantitatively detect the changes in NT-proBNP contents in various preservation solutions.The effects of basic buffer system, preservative Proclin300 and antibiotics on the preservation of NT-proBNP were analyzed using univariate analysis.The combination of various factors was then optimized using orthogonal experiments, to identify the best preservation system for NT-proBNP.Results: The univariate analysis determined that the basic buffer system for NT-proBNP was 0.02 mol/L phosphate buffered saline(PBS) at pH7.2,the addition of pre-servative Proclin300 could extend the preservation time of NT-proBNP at 37℃ by one day, the combined addition of penicillin and streptomycin prolonged the preservation time of NT-proBNP by one day compared with individually adding penicillin or streptomycin.The orthogonal experiments identified a preservation solution for NT-proBNP as 20%calf serum,1/1 000 Proclin300,120 U/ml penicillin and 80 U/ml streptomycin in a basic buffer system of 0.02 mol/L PBS at pH7.2.This solution was used to preserve an NT-proBNP reference sample at 37℃.Seven days later,the calibrated fixed-value of the sample at 37℃was only 1.3%lower than that at 4℃.Conclusion:Optimized NT-proBNP serum preservation solution could preserve NT-proBNP standard sample at 37℃ for seven days.