摘要
ObjectiveTo investigate the effect of different cytopathological grading standards on the efficiency of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) in the diagnosis of pancreatic cancer. MethodsRelated clinical data and pancreatic cytopathological results were collected from 256 patients with pancreatic space-occupying lesions who underwent EUS-FNA in The First Affiliated Hospital of Anhui Medical University from May 2011 to March 2019, and the influencing factors for the diagnostic efficiency of EUS-FNA were analyzed based on surgical pathology and follow-up results. The independent samples t-test or the Mann-Whitney U test was used for comparison of continuous data between two groups, and the chi-square test was used for comparison of categorical data between two groups. The receiver operating characteristic (ROC) curve was used to evaluate the value of different cytopathological grading standards in the diagnosis of pancreatic cancer. ResultsA total of 67 patients who were lost to follow-up were excluded, and a total of 189 patients were included in the study. According to the Papanicolaou cytopathological standard, there were 47 cases of heterotypic cells, 25 cases of suspected cancer cells, 20 cases of cancer cells, and 97 cases without tumor cells based on EUS-FNA. A total of 133 patients were confirmed to have pancreatic cancer by postoperative pathology and follow-up results, among whom 52 had no tumor cells, 36 had heterotypic cells, 25 had suspected cancer cells, and 20 had cancer cells based on cytopathological results. EUS-FNA had a true positive rate of 6090% (81 patients) and a false negative rate of 39.10% (52 patients) in the diagnosis of pancreatic cancer; for the 56 patients without pancreatic cancer, EUS-FNA had a false positive rate of 19.64% (11 patients) and a true negative rate of 80.36% (45 patients). EUS-FNA had an area under the ROC curve of 0.643 (95% confidence interval: 0.561-0.724) in the diagnosis of pancreatic cancer. In combination with different cytopathological grading standards and with the diagnostic criteria of “the identification of heterotypic cells or suspected cancer cells or cancer cells was considered positive”, “the identification of suspected cancer cells or cancer cells was considered positive”, and “the identification of cancer cells was considered positive”, the results showed that the diagnostic criteria of “the identification of heterotypic cells or suspected cancer cells or cancer cells was considered positive” improved the efficiency of EUS-FNA in the diagnosis of pancreatic cancer, with a sensitivity of 50.38% and a specificity of 75.00%. Among the 189 patients, 13 (6.88%) experienced complications after EUS-FNA, which included hyperamylasemia and abdominal pain. ConclusionThe combination of different cytopathological grading standards can help improve the efficiency of EUS-FNA in the diagnosis of pancreatic cancer.
摘要
Objective To analyze the compatibility of bone marrow mesenchymal stem cells (BMSCs) with amphiphilic peptide three-dimensional gel.Methods Three healthy 3-week old SD rats were taken for separating femur and tibia to obtain BMSCs,the BMSCs surface antigen was detected by flow cytometry;the 10 mg/mL RGD-cyclic amphiphilic peptide solution was added into the same volume of DMEM/F12 culture medium,after a few seconds,which was self assemble into three-dimensional gel.Three dimensional gel structure was observed by transmission electron microscope (TEM).1 × 106 cells/mL BMSCs suspension and RGDcyclic amphiphilic peptide were mixed to form a 3D culture system,1 × 106 cells/mL BMSCs suspension was mixed with polylysine to form a 2D culture system,the serum-free culture was conducted;the CCK-8 method was used to observe the cell growth situation,calcein acetoxy methyl ester/propidium iodide (PI) double standard staining was performed.The effect of RGD-cyclic amphiphilic peptide on the proliferation of BMSCs was observed by fluorescence microscopy.Results The separated and cultured BMSCs highly expressed CD29 and CD90,but lowly expressed or did not express CD34 and CD45;TEM showed that the gel was composed of multiple empty nanofibers with the nanofiber diameter of 2-5 nm and length of 100-1 000 nm;the molecular weight of synthetic peptides detected by mass spectrometry (MS) was 1 256.37,which was consistent with the theoretical value;the HPLC analysis showed that RGD-amphiphilic peptide purity was 95.88 %;the calcein acetoxyl methyl ester/PI double staining showed that in the 3D culture system,a few BMSCs died after 30 min and the cells began to proliferate after 12 h,the proliferation was more active than that of 2D culture,and the difference was statistically significant (P<0.05);CCK-8 cell count showed that the proliferation activity of 3D culture system was higher than that of 2D culture system,and the difference was statistically significant (P<0.05).Conclusion RGD amphiphilic peptide has a good biocompatibility with BMSCs,and may become the tissue engineering scaffold material.
摘要
Objective To explore the reliability of Chinese simplified diagnostic method for acute drug‐induced liver injury (DILI) in diagnosis of acute DILI .Methods From 2008 to 2013 ,a total of 320 patients diagnosed with acute DILI were enrolled .The clinical data of them were collected .International recognized Roussel Uclaf causality assessment method (RUCAM ) was taken as control and then simplified diagnostic method for DILI in China was evaluated . Variance analysis was performed for statistical analysis .Gamma value of two diagnostic methods was calculated and the correlation was analyzed .Results Among the 320 patients with acute DILI ,according to RUCAM ,there were 39 cases (12 .19% ) with quite high probability ,193 with high probability (60 .31% ) ,74 with possibility (23 .12% ) ,11 with less possibility (3 .44% ) and three with no probability (0 .94% ) .According to simplified diagnostic method for acute DILI ,194 cases were diagnosed (60 .62% ) ,103 were suspicious (32 .19% ) and 23 were excluded (7 .19% ) .The RUCAM score of diagnosed group (7 .5 ± 1 .2) was higher than that of suspicious group (5 .3 ± 1 .3) and excluded group (2 .1 ± 1 .1) ,and the difference was statistically significant (F =239 .545 ,P< 0 .01) .The correlation analysis between these two diagnostic methods indicated that Gamma value was 0 .955 (P < 0 .01) .Conclusions The simplified diagnostic method for acute DILI in China is simple ,practical and consistent with RUCAM .It can be used as one of the clinical methods for screening acute DILI .
摘要
Tricho-rhinophalangeal syndrome -1 gene(TRPS1),a new GATA family member,is highly prevalent in many tissues .It plays an important role in the regulation of cell proliferation and tissue development . The genetic missing of TRPS1 may lead to Tricho-rhinophalangeal syndrome .In recent years,studies have dem-onstrated that TRPS1 abnormal expression exists in a variety of tumors , and is associated with carcinogenesis , lymph node metastasis,pathological grading and clinical staging .Therefore,TRPS1 is considered as a potential tumor suppressor gene ,its overexpression may be one of mechanisms for carcinogenesis and progression of cancer . This review focuses on the role of TRPS 1 gene in carcinogenesis and progression of carcinoma ,and further to pro-vide a new biomarker for predicting cancer prognosis and therapy .
摘要
Ovarian cancer is the highest death rate of gynecologic malignant tumor .Currently,people rec-ognize standard treatment for ovarian cancer was that reduction -Tumor cells of platinum based chemotherapy af-ter surgery.But for those patients who have developed into advanced cancer that cannot be operated the surgeries directly,the application of preoperative Neoadjuvant chemotherapy ( NACT) does have the superiority .which is recognized by the majority of clinical doctors ,and has been widely used in the treatment of advanced malignant tumor.It is worthy to discussing which part of patients should choose the initial treatment of Neoadjuvant chemo -therapy,rather than a direct treatment of destroying tumor cells .This article is summarizing the empirical cases based on related research ,in order to help clinicians to make a decision on the treatment of ovarian cancer .
摘要
Titanium alloy has been used widely in fields of hard tissue replacement and repair,despite its characteristics of bio-inert material.Bio-ceramic coating deposited on Ti-based implants surface using surface modification technique can improve the bioactivity and biocompatibility of Ti-alloy material.The hydroxyapatite coating has been applied in clinic treatment,but this type of coating is still plagued with low crystallinity and poor bonding strength.In order to obtain an implant with excellent integrated properties,some novel bio-ceramic coating materials have been prepared.These materials having excellent bioactivity and biocompatibility and can directly bond with the Ti-based implants and the bone tissue.This review will present research status of the application of bio-ceramic coating on titanium alloy surface in biomedical fields
摘要
The angiogenesis induced with neotype amphiphilic peptide containing Isoleucine-Lysine-Valine-Alanine-Valine (IKVAV) was explored in vivo. The peptide was self-assembled into hydrogel, confirmed using transmission electron microscopy (TEM). One millilitre of 10 mg/ml peptide (experiment group, EG) and 16.67% gelatin (control group, CG) were injected subcutaneously beside rat backbone. The systemic response and local skin were observed one week after injection. The specimens were harvested two weeks later and immunohistochemically examined for vascular endothelial growth factor (VEGF). TEM showed that hydrogel was composed of interconnected nanofibers. The inflammatory reaction and necrosis of local skins were not found one week after injection. Lots of capillary vessels with complete wall were found within self-assembled peptide hydrogel, with erythrocytes noted inside the vessels in EG; the capillary vessels or erythrocytes were not found in the gelatin in CG. The immunohistochemical detection revealed VEGF-positive cells in EG, which were not found in CG. The self-assembly hydrogel from IKVAV-containing peptide was able to induce the angiogenesis in vivo.
Subject(s)
Animals , Rats , Hydrogels , Pharmacology , Laminin , Pharmacology , Neovascularization, Physiologic , Peptide Fragments , Pharmacology , Rats, Sprague-Dawley , Skin摘要
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.
Subject(s)
Animals , Rats , Animals, Newborn , Cell Culture Techniques , Cell Differentiation , Cells, Cultured , Hydrogel, Polyethylene Glycol Dimethacrylate , Chemistry , Metabolism , Nanofibers , Chemistry , Neural Stem Cells , Cell Biology , Neurogenesis , Peptides , Chemistry , Metabolism , Rats, Sprague-Dawley , Tissue Scaffolds , Chemistry摘要
In this experimental study, the RGD-containing peptide was used to modify the surface of biomimetic PLGA-(ASP-PEG) matrix, and bone marrow stromal cells (BMSCs) were seeded onto these modified surfaces for three weeks. The effects of modified surfaces of matrix on the adhesion, proliferation and differentiation of BMSCs were explored. BMSCs were harvested from whole bone marrow of Sprague-Dawley (SD) rats in vitro, then were seeded onto peptide surface-modified matrix (Experiment group, EG) and matrices without modification (Control group, CG) respectively for three weeks. The number of adhesive cells was counted by using precipitation method after 4 h and 12 h incubation; the cells cytoskeletons were stained with FITC-conjugated phalloidin after 24h incubation; the cell density was investigated after 1 d, 2 d and 3 d of incubation; ALP activity of BMSCs was measured after 7 d, 14 d and 21 d of incubation with osteogenic medium. The cells from bone marrow were BMSCs and their purity was beyond 90% using flow cytometry (FCM) analysis. Sulphur binding energy in EG was shown by XPS to be 164 eV. BMSCs adhered on peptide surface-modified matrix were observed with SEM. Cell adhesion efficiency and quality in EG was better than that in CG, and cell cytoskeleton was more robust in EG. ALP activity was higher in EG than in CG. Peptide surface-modified PLGA-(ASP-PEG) was noted to have good compatibility with BMSCs and to promote cell adhesion and differentiation.
Subject(s)
Animals , Rats , Biocompatible Materials , Chemistry , Bone Marrow Cells , Cell Biology , Metabolism , Cell Adhesion , Cell Differentiation , Lactic Acid , Chemistry , Oligopeptides , Chemistry , Osteoblasts , Cell Biology , Peptides , Chemistry , Polyglycolic Acid , Chemistry , Rats, Sprague-Dawley , Stromal Cells , Cell Biology , Metabolism , Surface Properties , Tissue Engineering , Tissue Scaffolds摘要
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.
Subject(s)
Biocompatible Materials , Chemistry , Bone Substitutes , Bone and Bones , Metabolism , Calcification, Physiologic , Lactic Acid , Chemistry , Oligopeptides , Chemistry , Osteogenesis , Peptides , Pharmacology , Polyglycolic Acid , Chemistry , Surface Properties摘要
The neotype of amphiphilic oligopeptide (C16 H31 O-AAAGGGGDDIKVAV) was synthesized. The framework of three-dimensional and porous hydrogel self-assembly from the amphiphilic oligopeptide on different conditions was explored. The peptide, whose molecular weight (MW) and purity were detected by Mass Spectrometer (MS) and High Performance Liquid Chromatograph (HPLC) respectively, was synthesized in solid phase methods. Peptide was dissolved in 0.1 mol/L Sodium Hydroxide (NaOH) solution. 200 microl of 10, 2, 1, 0.5 wt% peptide solutions, which were prepared respectively, were added into the same volume of DMEM/F12, or placed into the vapor of 10 mol/L Hydrochloric acid (HCl), or were used to coat in the surface of coverslip and set into the baking oven at 37 degrees C. The self-assembly hydrogel was examined with transmission electron microscope (TEM) and scanning electron microscope (SEM). MS showed that peptide MW was 1438.31. HPLC testified that the peptide purity was 96%. The peptide solution was self-supported into hydrogel triggered with DMEM/F12 in few seconds, or the thin hydrogel after two hours in the vapor of 10 mol/L HCl, or not hydrogel in the baking oven at 37 degrees C. SEM showed that the hydrogel self-assembly from 10 wt% peptide solution was composed of nanofibers that ranked in layers where there were thick voids. TEM showed that the hydrogel self-assembly from 2, 1, 0.5 wt% peptide solution comprised woven network nanofibers, that the nanofibers of hydrogel self-supported from 1 wt% peptide solution varied from 3 to 6 nm in diameter and 100 nm to 1.5 um in length, that the nanofibers of hydrogel self-supported from 2 wt% peptide solution ranked closely, and there were big voids within the thin nanofibers of hydrogel self-supported from 0.5 wt% peptide solution. The amphiphilic oligopeptide was synthesized and self-organized successfully into porous hydrogel characterized as "intelligent" tissue engineering scaffolds containing the bioactive ligand, which was triggered by DMEM/F12.
Subject(s)
Biocompatible Materials , Hydrogel, Polyethylene Glycol Dimethacrylate , Chemistry , Peptides , Chemistry , Porosity , Tissue Engineering , Methods , Tissue Scaffolds , Chemistry摘要
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.
摘要
Stem cell is one of the hot spot in the research area of biomedical engineering. Special attentions are drawn to the research and application of neural stem cells. Neural stem cells exist widely in central nervous system, which has the capacity of self-renewal and the potential to differentiate into other cells. The so-called engineered neural stem cell is constructed by using the technique of genetic engineering to make it be able to express various neural growth factors with high-performance and stability. The engineered neural stem cells have a great potential in the therapy of diseases of central nervous system, especially the spinal cord injury. This article reviews the research development of engineered neural stem cells, the problems confronted with it, and the trend for research in the future.
摘要
Arg-Gly-Asp-(RGD) containing peptide characterized as the non-viral gene vector was synthesized to modify the surface of PLGA-(ASP-PEG). The Peptide (K16-GRGDSPC) was synthesized. PLGA-(ASP-PEG) was executed into chips A, B and C. Chip C was regarded as control. Chips A and B reacted with the cross-linker, then Chip A reacted with peptide. Mass spectrometry (MS) and high performance liquid chromatography (HPLC) detected the molecular weight and the purity of peptide. Sulphur in the surface of materials was detected by X-ray photoelectron spectrometry (XPS). The peptide content in the residual solution was detected by Spectrometer. HPLC showed the peptide purity was 94.13%; MS showed the molecular weight was 2741.26. XPS revealed the binding energy of the sulphur in reacted Chip A was 164 eV in reacted Chip B, 164eV and 162 eV; the ratios of carbon to sulphur in reacted Chip A and B were 99.746:0.1014 and 99.574:0.4255, respectively. There was no sulphur in Chip C. The optical density value (OD) of the resident solution was 0.069. The peptide density of reacted Chip A was 0.04 mg/mm2. The peptide was manufactured and linked to the surface of the biomimetic PLGA-(ASP-PEG) with the cross-linker.
Subject(s)
Humans , Aspartic Acid , Chemistry , Biocompatible Materials , Chemistry , Cross-Linking Reagents , Chemistry , Genetic Vectors , Chemistry , Lactic Acid , Chemistry , Oligopeptides , Chemistry , Polyethylene Glycols , Chemistry , Polyglycolic Acid , Chemistry , Surface Properties , Tissue Engineering摘要
The nerve tissue engineering is to apply scalfolds and seed cells for the treatment of injury or disease of nerve system by restoring their anatomic structures and funetiorm.The scaffolds played important roles in supporting and conducting axonal regeneration.They could also limit the in-growth of scar tissue and hence help to build the connection between axonal and target cell.Self-assembling peptide scaffold is one of the excellent material used is nerve tissue engineering.This article reviews the self-assembling peptide based scaffolds for nerve tissue engineering and discusses the unsolved problems in the fields and the trend d the related research in the future.
摘要
In this study we examined the in vitro characteristics of MSCs adhesion to polypeptides modified surface of polymer PLGA-[ASP-PEG]. We study the adhesion of marrow stromal cells in biomaterials at diferrent times using a micropipette aspiration technique. Comparison the adhesion of PLGA-[ASP-PEG] combinating GRGDSPC polypeptides versus PLGA-[ASP-PEG]. The adhesive conditions of MSCs on the materials were observed by scanning electron microscope. Four hours after MSCs inoculating in biomerials, the cell adhesion force of PLGA-[ASP-PEG] is 172.78 +/- 15. 23N and the force of PLGA-[ASP-PEG] combinating GRGDSPC polypeptides is 209.47 +/- 92.59N. There are no difference between two biomaterials. After 12 hours,the adhesion force of PLGA-[ASP-PEG] combinating GRGDSPC polypeptides is 576.23 +/- 165.74N, and the cell force of PLGA-[ASP-PEG] is 261.84 +/- 100.09 N. There are very significant difference between the two biomaterials. However, after 24 hours,the adhesion forces of the two biomaterials have no difference. The density of MSCs on PLGA-[ASP-PEG]-GRGDSPC surface was much higher than that of PLGA-[ASP-PEG]. Combination polypeptides in the surface of biomaterials can enhance the adhesion of MSCs.
Subject(s)
Animals , Female , Male , Rats , Animals, Newborn , Aspartic Acid , Chemistry , Biocompatible Materials , Chemistry , Bone Marrow Cells , Cell Biology , Cell Adhesion , Cells, Cultured , Lactic Acid , Chemistry , Mesenchymal Stem Cells , Cell Biology , Peptides , Chemistry , Polyglycolic Acid , Chemistry , Rats, Sprague-Dawley , Tissue Engineering摘要
A 23 amino acid, bifunctional integrin-targeted synthetic oligopeptide was evaluated for ex vivo gene delivery to rabbit bone marrow stromal cells (BMSCs). Synthesis of the peptide (K)16GRGDSPC was performed on a solid-phase batch peptide synthesizer. BMSCs were transfected with plasmid DNA coding for luciferase by (K)16GRGDSPC and the transfection efficiency was assayed. The influences of chloroquine and polyethyleneimine on the transfection efficiency were also examined. The target specificity of (K)16GRGDSPC to mediate exogenous gene into BMSCs was analyzed using cell attachment test and gene delivery inhibition test. The results showed that the transfection efficiency of the oligopeptide vector was lower than that of Lipofectamine. But in the presence of endosomal buffer chloroquine or endosomal disrupting agent polyethyleneimine, the transfection efficiency of the vector was greatly enhanced. In addition, RGD-containing peptides inhibited BMSCs' attachment to the 96-well plates pretreated with fibronectin or vitronectin and significantly decreased the transfection efficiency of the oligopeptide vector. These studies demonstrated that oligopeptide (K)16GRGDSPC was an ideal novel targeted non-viral gene delivery vector, which was easy to be synthesized, high efficient and low cytotoxicity. The vector could effectively deliver exogenous gene into rat BMSCs.
摘要
Lack of biocompatibility and bioactivity is a big problem for the synthetic materials that have been generated for neural tissue engineering. To get around the problem and generate better scaffold for neural tissue repair, we intended to generate nano-fibers by self-assembly of polypeptide IKVAV. Bioactive IKVAV Peptide-Amphiphile (IKVAV-PA) was first synthesized and purified, the property of which was analyzed and determined by high-performance liquid chromatography (HPLC) and mass spectrometry (MS). Then, by addition of hydrogen chloride (HCl), self-assembly of IK-VAV-PA was induced in vitro and nano-fibers formed as shown by transmission electron microscopy (TEM). The effect of IKVAV nanofibers on adherence of PC12 cells was assayed in cell culture and the results showed that the rates of adherence of PC12 increased significantly when the density of IKVAV was within a certain range (0.58 microg/cm2 to 15.6 microg/cm2). However, its effect on the rates of adherence did not significantly alter with time, whether after 1 hour or 3 hours of culture. In general, we showed that IKVAV-PA can successfully self-assemble to form nanofiber, and promote rapid and stable adherence of PC12 cells, and the effect of the self-assembled IKVAV to promote PC12 cells adherence is dosage-dependent within a certain range of densities.
摘要
Lack of biocompatibility and bioactivity is a big problem for the synthetic materials that have been generated for neural tissue engineering. To get around the problem and generate better scaffold for neural tissue repair, we intended to generate nano-fibers by self-assembly of polypeptide IKVAV. Bioactive IKVAV Peptide-Amphiphile (IKVAV-PA) was first synthesized and purified, the property of which was analyzed and determined by high-performance liquid chromatography (HPLC)and mass spectrometry (MS). Then, by addition of hydrogen chloride (HCl), self-assembly of IKVAV-PA was induced in vitro and nano-fibers formed as shown by transmission electron microscopy (TEM). The effect of IKVAV nanofibers on adherence of PC12 cells was assayed in cell culture and the results showed that the rates of adherence of PC12 increased significantly when the density of IKVAV was within a certain range (0.58 μg/cm2 to 15.6 μg/cm2). However, its effect on the rates of adherence did not significantly alter with time, whether after 1 hour or 3 hours of culture. In general,we showed that IKVAV-PA can successfully self-assemble to form nanofiber, and promote rapid and stable adherence of PC12 cells, and the effect of the self-assembled IKVAV to promote PC12 cells adherence is dosage-dependent within a certain range of densities.
摘要
A 23 amino acid, bifunctional integrin-targeted synthetic oligopeptide was evaluated for ex vivo gene delivery to rabbit bone marrow stromal cells (BMSCs). Synthesis of the peptide (K)16GRGDSPC was performed on a solid-phase batch peptide synthesizer. BMSCs were transfected with plasmid DNA coding for luciferase by (K)16GRGDSPC and the transfection efficiency was assayed. The influences of chloroquine and polyethyleneimine on the transfection efficiency were also examined. The target specificity of (K)16GRGDSPC to mediate exogenous gene into BMSCs was analyzed using cell attachment test and gene delivery inhibition test. The results showed that the transfection efficiency of the oligopeptide vector was lower than that of Lipofectamine. But in the presence of endosomal buffer chloroquine or endosomal disrupting agent polyethyleneimine, the transfection efficiency of the vector was greatly enhanced. In addition, RGD-containing peptides inhibited BMSCs' attachment to the 96-well plates pretreated with fibronectin or vitronectin and significantly decreased the transfection efficiency of the oligopeptide vector. These studies demonstrated that oligopeptide (K)16GRGDSPC was an ideal novel targeted non-viral gene delivery vector, which was easy to be synthesized, high efficient and low cytotoxicity. The vector could effectively deliver exogenous gene into rat BMSCs.