Peripheral nerves are fragile and easily damaged,usually resulting in nervous tissue loss,motor and sensory function loss.Advances in neuroscience and engineering have been significantly contributing to bridge the dam...Peripheral nerves are fragile and easily damaged,usually resulting in nervous tissue loss,motor and sensory function loss.Advances in neuroscience and engineering have been significantly contributing to bridge the damage nerve and create permissive environment for axonal regrowth across lesions.We have successfully designed two self-assembling peptides by modifying RADA 16-I with two functional motifs IKVAV and RGD.Nanofiber hydrogel formed when combing the two neutral solutions together,defined as RADA 16-Mix that overcomes the main drawback of RADA16-I associated with low pH.In the present study,we transplanted the RADA 16-Mix hydrogel into the transected rat sciatic nerve gap and effect on axonal regeneration was examined and compared with the traditional RADA16-I hydrogel.The regenerated nerves were found to grow along the walls of the large cavities formed in the graft of RADA16-I hydrogel,while the nerves grew into the RADA 16-Mix hydrogel toward distal position.RADA 16-Mix hydrogel induced more axons regeneration and Schwann cells immigration than RADA16-I hydrogel,resulting in better functional recovery as determined by the gait-stance duration percentage and the formation of new neuromuscular junction structures.Therefore,our results indicated that the functional SAP RADA16-Mix nanofibrous hydrogel provided a better environment for peripheral nerve regeneration than RADA16-I hydrogel and could be potentially used in peripheral nerve injury repair.展开更多
This study examined the effect of IKVAV peptide nanofiber on proliferation, adhesion and differentiation into neurocytes of bone marrow stromal cells （BMSCs）. IKVAV Peptide-amphiphile was synthesized and purified. T...This study examined the effect of IKVAV peptide nanofiber on proliferation, adhesion and differentiation into neurocytes of bone marrow stromal cells （BMSCs）. IKVAV Peptide-amphiphile was synthesized and purified. Then, hydrogen chloride was added to the diluted aqueous solutions of PA to induce spontaneous formation of nanofiber in vitro. The resultant samples was observed tmder transmission electron microscope. BMSCs were cultured with IKVAV peptide nanofiber. The effect of IKVAV nanofiber on the proliferation, adhesion and induction differentiation of BMSCs was observed by inverted microscopy, calcein-AM/PI staining, cell counting and immunofluorescence staining. The results demonstrated that IKVAV peptide-amphiphile could self-assemble to form nanofiber gel. BMSCs cultured in combination with IKVAV peptide nanofiber gel grew well and the percentage of live cells was over 90%. IKVAV peptide nanofiber gel exerted no influence on the proliferation of BMSCs and could promote the adhesion of BMSCs and raise the ra- tio of neurons when BMSCs were induced to differentiate into neurocytes. It is concluded that BMSCs could proliferate and adhere well and yield more neurons during when induced to differente into neurocytes on IKVAV peptide nanofiber gel.展开更多
The novel hydrogels-grafted IKVAV poly（lactide-co-ethylene oxide-co-fumarate）（PLEOF） hydrogels（GIPHs） were developed. The rat bone marrow mesenchymal stem cells（BMMSCs） were employed, and the cell vitality and...The novel hydrogels-grafted IKVAV poly（lactide-co-ethylene oxide-co-fumarate）（PLEOF） hydrogels（GIPHs） were developed. The rat bone marrow mesenchymal stem cells（BMMSCs） were employed, and the cell vitality and apoptosis assays were carried out to evaluate the cytocomptibility of GIPHs. Our data demonstrated that the infl uence of GIPHs on the proliferation of BMMSCs was in a concentration and time dependent manner. The proliferative ability of BMMSCs in GIPHs-treated group（100 μg/mL） after 72 h presented a maximum response which was 30.1% more than that of control group. The numbers of apoptotic cells in GIPHs-treated group（100 μg/mL） were just as much as that of control group after 24 h treatment. The GIPHs are able to provide an appropriate environment for BMMSCs survival and proliferation.展开更多
This present work aims to functionalize poly（amidoamine） （PAMAM） dendrimers with various reported adhesive peptides, including Arg-Gly-Asp （RGD）, Tyr-lle-Gly-Ser-Arg （YIGSR）, and Ile-Lys-Val-Ala-Val （IKVAV） ...This present work aims to functionalize poly（amidoamine） （PAMAM） dendrimers with various reported adhesive peptides, including Arg-Gly-Asp （RGD）, Tyr-lle-Gly-Ser-Arg （YIGSR）, and Ile-Lys-Val-Ala-Val （IKVAV） for enhancing cell responses. The RGD, YIGSR, or IKVAV functionalized PAMAM coated substrate could promote cell adhesion of bone marrow mesenchymal stem cells （BMSCs） within 1 h after incubation. The neurite differentiation and proliferation of pheochromocytoma （PC12） cells were also significantly enhanced after culturing on the peptide functionalized PAMAM dendrimers for two and foul days. This peptide functionalized PAMAM dendrimers are considered as the potential candidates for various tissue engineering applications.展开更多
Neural Stem Cells （NSCs） were incubated with self-assembled hydrogel from IKVAV-containing peptide amphiphile （IKVAV-PA） for one week. The cytocompatibility of hydrogel was evaluated. NSCs were seeded in three-dim...Neural Stem Cells （NSCs） were incubated with self-assembled hydrogel from IKVAV-containing peptide amphiphile （IKVAV-PA） for one week. The cytocompatibility of hydrogel was evaluated. NSCs were seeded in three-dimensional （3D） hydrogels （Experimental Group, EG） or surface of coverslips （Control Group, CG）, double-labeled with Calcein-AM and PI. A growth curve of cells was obtained according to CCK-8. TEM study of hydrogel revealed a network of nanofibers. NSCs began to proliferate after 24 h of incubation, and formed bigger neurospheres at 48 h in EG than in CG. Cell proliferation activity was higher in EG than in CG （P〈0.05）. The self-assembled Hydrogel had good cytocompatibility and promoted the proliferation of NSCs.展开更多
An IKVAV （Isoleucine-Lysine-Valine-Alanine-Valine）-containing peptide amphiphile molecule （IKVAV-PA） was implanted subcutaneouly into rat backbone in the middle. Angiogenesis induced by IKVAV-PA was evaluated in v...An IKVAV （Isoleucine-Lysine-Valine-Alanine-Valine）-containing peptide amphiphile molecule （IKVAV-PA） was implanted subcutaneouly into rat backbone in the middle. Angiogenesis induced by IKVAV-PA was evaluated in vivo. 200 μL of 10, 2, 1 and 0.5 wt% IKVAV-PA solution were added into DMEM/F12 and self-assembled into nanofiber hydrogel. 1 mL of 1% IKVAV-PA （Experimental Group, EG） and 1 mL of 16.67% gelatin （Control Group, CG） were injected subcutaneously into rat backbone. The specimens were harvested two weeks after injection and examined immunohistochemically for VEGF（Vascular Endothelial Growth Factor）. TEM observations of hydrogels revealed a network of nanofibers, and there was a significant positive correlation between IKVAV-PA concentration and nanofiber alignment. Light microscopy observation showed capillary vessel with complete walls formed in hydrogel, with erythrocytes noted inside the vessels in EG; capillary vessels or erythrocytes were not found within gelatin in CG. Immunohistochemical analysis revealed that there were VEGF-positive cells within hydrogel, which were not found in CG. Self-assembled hydrogel from IKVAV-PA was able to induce the angiogenesis in vivo.展开更多
基金The authors thank for funding supports from the National Program on Key Basic Research Project(973 Program,2014CB542205)Hong Kong RGC grant(17124514)+5 种基金Foundation for Distinguished Young Talents in Higher Education of Guangdong(Yq2013023)Pearl River Nova Program of Guangzhou(2014J2200001)China Postdoctoral Science Foundation(2013M540684)the Leading Talents of Guangdong Province(87014002)National Natural Science Foundation of China(51103062)The authors wish to acknowledge the support from the Hong Kong Scholars Program(XJ2012024).
文摘Peripheral nerves are fragile and easily damaged,usually resulting in nervous tissue loss,motor and sensory function loss.Advances in neuroscience and engineering have been significantly contributing to bridge the damage nerve and create permissive environment for axonal regrowth across lesions.We have successfully designed two self-assembling peptides by modifying RADA 16-I with two functional motifs IKVAV and RGD.Nanofiber hydrogel formed when combing the two neutral solutions together,defined as RADA 16-Mix that overcomes the main drawback of RADA16-I associated with low pH.In the present study,we transplanted the RADA 16-Mix hydrogel into the transected rat sciatic nerve gap and effect on axonal regeneration was examined and compared with the traditional RADA16-I hydrogel.The regenerated nerves were found to grow along the walls of the large cavities formed in the graft of RADA16-I hydrogel,while the nerves grew into the RADA 16-Mix hydrogel toward distal position.RADA 16-Mix hydrogel induced more axons regeneration and Schwann cells immigration than RADA16-I hydrogel,resulting in better functional recovery as determined by the gait-stance duration percentage and the formation of new neuromuscular junction structures.Therefore,our results indicated that the functional SAP RADA16-Mix nanofibrous hydrogel provided a better environment for peripheral nerve regeneration than RADA16-I hydrogel and could be potentially used in peripheral nerve injury repair.
基金supported by grants from the National Natural Sciences Foundation of China (No. 30500511)the National High-tech Research Program (No. 2006AA320 605)
文摘This study examined the effect of IKVAV peptide nanofiber on proliferation, adhesion and differentiation into neurocytes of bone marrow stromal cells （BMSCs）. IKVAV Peptide-amphiphile was synthesized and purified. Then, hydrogen chloride was added to the diluted aqueous solutions of PA to induce spontaneous formation of nanofiber in vitro. The resultant samples was observed tmder transmission electron microscope. BMSCs were cultured with IKVAV peptide nanofiber. The effect of IKVAV nanofiber on the proliferation, adhesion and induction differentiation of BMSCs was observed by inverted microscopy, calcein-AM/PI staining, cell counting and immunofluorescence staining. The results demonstrated that IKVAV peptide-amphiphile could self-assemble to form nanofiber gel. BMSCs cultured in combination with IKVAV peptide nanofiber gel grew well and the percentage of live cells was over 90%. IKVAV peptide nanofiber gel exerted no influence on the proliferation of BMSCs and could promote the adhesion of BMSCs and raise the ra- tio of neurons when BMSCs were induced to differentiate into neurocytes. It is concluded that BMSCs could proliferate and adhere well and yield more neurons during when induced to differente into neurocytes on IKVAV peptide nanofiber gel.
基金Funded by theNational Basic Research Program of China(No.2011CB606205)the Self-determined and Innovative Research Funds of WUT(No.2012-YB-007)
文摘The novel hydrogels-grafted IKVAV poly（lactide-co-ethylene oxide-co-fumarate）（PLEOF） hydrogels（GIPHs） were developed. The rat bone marrow mesenchymal stem cells（BMMSCs） were employed, and the cell vitality and apoptosis assays were carried out to evaluate the cytocomptibility of GIPHs. Our data demonstrated that the infl uence of GIPHs on the proliferation of BMMSCs was in a concentration and time dependent manner. The proliferative ability of BMMSCs in GIPHs-treated group（100 μg/mL） after 72 h presented a maximum response which was 30.1% more than that of control group. The numbers of apoptotic cells in GIPHs-treated group（100 μg/mL） were just as much as that of control group after 24 h treatment. The GIPHs are able to provide an appropriate environment for BMMSCs survival and proliferation.
基金financially supported by the NSF-ECCS 1509760NSF EPSCoR RII Track 1 cooperative agreement awarded to the University of South Carolina (NSF EPSCoR Cooperative Agreement No. EPS-0903795)
文摘This present work aims to functionalize poly（amidoamine） （PAMAM） dendrimers with various reported adhesive peptides, including Arg-Gly-Asp （RGD）, Tyr-lle-Gly-Ser-Arg （YIGSR）, and Ile-Lys-Val-Ala-Val （IKVAV） for enhancing cell responses. The RGD, YIGSR, or IKVAV functionalized PAMAM coated substrate could promote cell adhesion of bone marrow mesenchymal stem cells （BMSCs） within 1 h after incubation. The neurite differentiation and proliferation of pheochromocytoma （PC12） cells were also significantly enhanced after culturing on the peptide functionalized PAMAM dendrimers for two and foul days. This peptide functionalized PAMAM dendrimers are considered as the potential candidates for various tissue engineering applications.
文摘Neural Stem Cells （NSCs） were incubated with self-assembled hydrogel from IKVAV-containing peptide amphiphile （IKVAV-PA） for one week. The cytocompatibility of hydrogel was evaluated. NSCs were seeded in three-dimensional （3D） hydrogels （Experimental Group, EG） or surface of coverslips （Control Group, CG）, double-labeled with Calcein-AM and PI. A growth curve of cells was obtained according to CCK-8. TEM study of hydrogel revealed a network of nanofibers. NSCs began to proliferate after 24 h of incubation, and formed bigger neurospheres at 48 h in EG than in CG. Cell proliferation activity was higher in EG than in CG （P〈0.05）. The self-assembled Hydrogel had good cytocompatibility and promoted the proliferation of NSCs.
文摘An IKVAV （Isoleucine-Lysine-Valine-Alanine-Valine）-containing peptide amphiphile molecule （IKVAV-PA） was implanted subcutaneouly into rat backbone in the middle. Angiogenesis induced by IKVAV-PA was evaluated in vivo. 200 μL of 10, 2, 1 and 0.5 wt% IKVAV-PA solution were added into DMEM/F12 and self-assembled into nanofiber hydrogel. 1 mL of 1% IKVAV-PA （Experimental Group, EG） and 1 mL of 16.67% gelatin （Control Group, CG） were injected subcutaneously into rat backbone. The specimens were harvested two weeks after injection and examined immunohistochemically for VEGF（Vascular Endothelial Growth Factor）. TEM observations of hydrogels revealed a network of nanofibers, and there was a significant positive correlation between IKVAV-PA concentration and nanofiber alignment. Light microscopy observation showed capillary vessel with complete walls formed in hydrogel, with erythrocytes noted inside the vessels in EG; capillary vessels or erythrocytes were not found within gelatin in CG. Immunohistochemical analysis revealed that there were VEGF-positive cells within hydrogel, which were not found in CG. Self-assembled hydrogel from IKVAV-PA was able to induce the angiogenesis in vivo.
