PuraStat®is a novel self-assembling peptide(SAP)used as a haemostatic agent in endoscopy,with widespread application in surgical settings.While the current evidence,though deserving further expansion,demonstrates...PuraStat®is a novel self-assembling peptide(SAP)used as a haemostatic agent in endoscopy,with widespread application in surgical settings.While the current evidence,though deserving further expansion,demonstrates a good haemostatic performance profile for this substance,there remains significant heterogeneity among studies,and an analysis of this SAP as monotherapy is not always available.The recent study by Bellester et al in the World Journal of Gastrointestinal Endoscopy provided an optimal effectiveness profile of this SAP in 45 patients treated for gastrointestinal(GI)bleeding,particularly highlighting data on its use as monotherapy in upper GI bleeding.This invited article outlines the current evidence on PuraStat®and offers a commentary on the recently published study.展开更多
In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold （SAPNS）-containing poly（lactic-co-glycolic acid） （PLGA） conduit （SPC） and used it to bridge a 10-mm-...In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold （SAPNS）-containing poly（lactic-co-glycolic acid） （PLGA） conduit （SPC） and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myofiber diameter in the target muscle. These findings suggest that the novel artificial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury.展开更多
Thrombosis is the major stumbling block to the clinical application of blood-contacting devices.Herein,a quick and easy surface engineering strategy of hydrogel coating with the therapeutic gas nitric oxide(NO)generat...Thrombosis is the major stumbling block to the clinical application of blood-contacting devices.Herein,a quick and easy surface engineering strategy of hydrogel coating with the therapeutic gas nitric oxide(NO)generation was reported to realize up-regulation of cyclic guanosine monophosphate(c GMP)and improve hemocompatibility for diverse metal materials.We first introduce the active centre selenocysteine of glutathione peroxidase(GPx)to the self-assembling peptide(RADA)4,obtaining a functionalized hydrogel.Then the hydrogel is directly coated on the 316L stainless steel(SS)for catalytically generating NO from endogenous s-nitrosothiols(RSNO).The generated NO endows the coated surface with regulation of platelet behavior and reduction of plasmatic coagulation activation and complement system activation,hence improving antithrombotic ability in vitro and ex vivo.Overall,our NO-generating hydrogel coating surface engineering strategy provides a novel solution to remove the obstacle about thrombosis of blood-contacting devices in clinic.展开更多
Following injury in central nervous system（CNS）,there are pathological changes in the injured region,which include neuronal death,axonal damage and demyelination,inflammatory response and activation of glial cells.T...Following injury in central nervous system（CNS）,there are pathological changes in the injured region,which include neuronal death,axonal damage and demyelination,inflammatory response and activation of glial cells.The proliferation of a large number of astrocytes results in the formation of glial scar.展开更多
The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells （PSCs） into chondrocytes was studied. KLD-12 was synthesized by so...The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells （PSCs） into chondrocytes was studied. KLD-12 was synthesized by solid-state method. After TGF-β3 plasmid was loaded into KLD-12 self-assembling peptide nanofiber scaffold, DNA release ability was investigated. PSCs and hTGF-β3 gene were loaded into KLD-12 3-D scaffold, and MTT assay was performed to investigate the cell proliferation, and ELASA assay was used to investigate the expression of TGF-β3. Specific cartilage matrix was examined by quantitative real-time PCR, immunohistochemistry and Alcian Blue staining. Compared with control group, DNA synthesis level of PSCs reached the peak within 3 days when PSCs were cultured in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, and maintained this high level within 2 weeks. MTT results showed that the proliferation ability of experimental group was statistically higher than that in control group （P〈0.05）. Quantitative real-time PCR suggested that the percentage of TGF-β3 positive PSCs in experimental group was higher than that in control group （P〈0.01）. ELISA assay showed that the TGF-β3 protein level increased in supernatant of experimental group＇s PSCs, reached the peak after 72 h and then declined a little to the plateau phase. Compared with the control group, the specific gene of chondrocyte typical extracellular matrix significantly up-regulated （P〈0.01）. The results showed that PSCs differentiated into chondrocytes in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, which provided a fresh approach to cartilage tissue engineering.展开更多
Vascular endothelial growth factor(VEGF)-vascular endothelial growth factor receptor(VEGFR)pathways are essential in tumor angiogenesis,growth and metastasis.Studies on anti-angiogenic therapy have been mostly focused...Vascular endothelial growth factor(VEGF)-vascular endothelial growth factor receptor(VEGFR)pathways are essential in tumor angiogenesis,growth and metastasis.Studies on anti-angiogenic therapy have been mostly focused on the blockage of VEGF-VEGFR pathways.We report an extracellularly transformable peptide-based nanomaterial to develop artificial extracellular matrix(ECM)-like networks for high-efficient blockage of natural VEGF-VEGFR interactions.The transformable peptide-based nanomaterial transforms from nanoparticles into nanofibers upon binding to VEGFR in solution.In addition,the transformable peptide-based nanomate rial forms ECM-like fibrous netwo rks on VEGFR overexpressed cells,inhibiting the VEGF-VEGFR interactions and the subsequent angiogenesis.The tube formation is reduced by nearly 85.1% after treatment.This strategy shows excellent potential for anti-angiogenesis,and inhibition of tumor invasion and metastasis.展开更多
Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-bu...Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-building blocks, can form nanostructures with different functions,either in solutions or on interfaces. Previously, we synthesized a short peptide with the inspiration of an Alzheimer’s disease-related peptide: amyloid β peptide(A-p),namely GAV-9, which can epitaxially self-assemble into regular nanofilaments on liquid-solid interfaces, and it was found that both the hydrophobicity and charge state of the interfaces can significantly influence its assembling behavior. It was also reported that another A-β-containing dipeptide, FF,can self-assemble into nanostructures in solutions. Owing to the close relationship between these two short peptides, it is interesting to conjugate them into a de novo peptide with two separated structural domains and study its self-assembling behavior. To this end, herein we have synthesized the GAV-FF peptide with a sequence of NH2-VGGAVVAGVFF-CONH2 and verified its selfassembling property using the in situ liquid-phase atomic force microscopy. The results show that the GAV-FF peptide can self-assemble into nanofilaments both in solutions and on aqueous-solid interfaces, but with different morphologies. The FF domain accelerates the template-assisted self-assembling(TASA) process of the GAV domain, which in return enhances the solubility of FF in aqueous solutions and further participates in the fibrillization of FF. The current results could help deepen the understanding of the aggregation mechanism of diseaserelated peptides and could also shed light on the strategies to create artificial bio-functional nanostructures/patterns,which hold a significant potential for biomedical applications.展开更多
The potential application of a designed self-assembly peptide CH3CO-Pro-Thr-Phe-CysPhe-Lys-Phe-Glu-Pro-NH2（named as P1） as a carrier of 5-Fluorouracil（5-Fu） for controlled release in vitro was studied. 5-Fluoroura...The potential application of a designed self-assembly peptide CH3CO-Pro-Thr-Phe-CysPhe-Lys-Phe-Glu-Pro-NH2（named as P1） as a carrier of 5-Fluorouracil（5-Fu） for controlled release in vitro was studied. 5-Fluorouracil（5-Fu） was selected as a representative anticancer drug due to its extensive use in treating digestive system cancer and breast cancer. The interaction between P1 and 5-Fu was detected by fluorescent quenching experiments and atomic force microscopy（AFM）. The quenching mechanism of 5-Fu and P1 system was dynamic by performing fluorescent quenching experiments at different temperatures. The thermodynamic analysis demonstrated that the interaction between 5-Fu and P1 was hydrophobic interaction. The complexes prepared by the interaction between peptide and 5-Fu appeared as large granular particles of about 20 nm in height under AFM（denoted as5-Fu-P1）, 24 times larger than the original 5-Fu particles. According to the results, an interaction model was proposed. Furthermore, 5-Fu-P1 complexes exhibited an efficient controlled release of 5-Fu in vitro. The research suggested that P1 might be a candidate carrier for drug delivery, providing a substitution agent for 5-Fu.展开更多
Androgenetic alopecia(AGA),the most prevalent form of hair loss,urgently requires breakthroughs in existing therapies due to limitations such as medication side effects,recurrence risks,and treatment inefficacy.Herein...Androgenetic alopecia(AGA),the most prevalent form of hair loss,urgently requires breakthroughs in existing therapies due to limitations such as medication side effects,recurrence risks,and treatment inefficacy.Herein,we propose an insulin-derived self-assembling sequence Ac-GFFY,combined with the C domain peptide of insulin-like growth factor 1,successfully designing an IGF-1 biomimetic peptide factor,Ac-GFFY-IGF,which can substitute for the absent IGF-1 in the AGA pathological environment and facilitate hair regrowth.Compared with IGF-1,Ac-GFFY-IGF exhibits superior in vitro stability and enhanced skin permeability.In the murine AGA model,Ac-GFFY-IGF demonstrated superior efficacy to the clinically used minoxidil,achieving faster hair regeneration,higher hair quality,and broader hair coverage at lower concentrations.Our strategy provides a critical theoretical foundation and technical pathway for developing novel mechanism-driven therapies for AGA.展开更多
Nerve guidance conduits with hollow lumen fail to regenerate critical-sized peripheral nerve defects(15 mm in rats and 25 mm in humans),which can be improved by a beneficial intraluminal microenvironment.However,indiv...Nerve guidance conduits with hollow lumen fail to regenerate critical-sized peripheral nerve defects(15 mm in rats and 25 mm in humans),which can be improved by a beneficial intraluminal microenvironment.However,individual cues provided by intraluminal filling materials are inadequate to eliminate the functional gap between regenerated nerves and normal nerves.Herein,an aligned fibrin/functionalized self-assembling peptide(AFG/fSAP)interpenetrating nanofiber hydrogel that exerting synergistic topographical and biochemical cues for peripheral nerve regeneration is constructed via electrospinning and molecular self-assembly.The hydrogel possesses an aligned structure,high water content,appropriate mechanical properties and suitable biodegradation capabilities for nerve repair,which enhances the alignment and neurotrophin secretion of primary Schwann cells(SCs)in vitro,and successfully bridges a 15-mm sciatic nerve gap in rats in vivo.The rats transplanted with the AFG/fSAP hydrogel exhibit satisfactory morphological and functional recovery in myelinated nerve fibers and innervated muscles.The motor function recovery facilitated by the AFG/fSAP hydrogel is comparable with that of autografts.Moreover,the AFG/fSAP hydrogel upregulates the regeneration-associated gene expression and activates the PI3K/Akt and MAPK signaling pathways in the regenerated nerve.Altogether,the AFG/fSAP hydrogel represents a promising approach for peripheral nerve repair through an integration of structural guidance and biochemical stimulation.展开更多
Nerve guidance conduit （NGC） is a potential alternative to autologous nerve for peripheral nerve regeneration. A promising therapeutic strategy is to modify the nerve guidance conduit intraluminal microenvironment u...Nerve guidance conduit （NGC） is a potential alternative to autologous nerve for peripheral nerve regeneration. A promising therapeutic strategy is to modify the nerve guidance conduit intraluminal microenvironment using physical and/or chemical guidance cues. In this study, a neurotrophic peptide-functionalized self-assembling peptide nanofiber hydrogel that could promote PC12 cell adhesion, proliferation, and neuronal differentiation in vitro was prefilled in the lumen of a hollow chitosan tube （hCST） to accelerate axonal regeneration in a rat sciatic nerve defect model. The functionalized self-assembling peptide was developed by introducing a neurotrophic peptide （RGI, RGIDKRHWNSQ） derived from brain-derived neurotrophic factor （BDNF） to the C-terminus of the self-assembling peptide RADA16-I （Ac-（RADA）4-CONH2）. Morphological, histological, electrophysiological, and functional analyses demonstrated that the RGI-functionalized, self-assembling, peptide nanofiber hydrogel RAD/RGI could produce a neurotrophic microenvironment that markedly improved axonal regeneration with enhanced re-myelination and motor functional recovery.展开更多
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
Central nervous system （CNS） presents a complex regeneration problem due to the inability of central neurons to regenerate correct axonal and dendritic connections. However, recent advances in developmental neurobio...Central nervous system （CNS） presents a complex regeneration problem due to the inability of central neurons to regenerate correct axonal and dendritic connections. However, recent advances in developmental neurobiology, cell signaling, cell-matrix interaction, and biomaterials technologies have forced a reconsideration of CNS regeneration potentials from the viewpoint of tissue engineering and regenerative medicine. The applications of a novel tissue regeneration-inducing biomaterial and stem cells are thought to be critical for the mission. The use of peptide nanoflber hydrogels in cell therapy and tissue engineering offers promising perspectives for CNS regeneration. Self-assembling peptide undergo a rapid transformation from liquid to gel upon addition of counterions or pH adjustment, directly integrating with the host tissue. The peptide nanofiber hydrogels have mechanical properties that closely match the native central nervous extracellular matrix, which could enhance axonal growth. Such materials can provide an optimal three dimensional microenvironment for encapsulated cells. These materials can also be tailored with bioactive motifs to modulate the wound environment and enhance regeneration. This review intends to detail the recent status of selfassembling peptide nanoflber hydrogels for CNS regeneration.展开更多
Self-assembling peptides （SAPs） are synthetic bioinspired biomaterials that can be feasibly multi-functionalized for cell transplantation and/or drug delivery therapies. Despite their superior biocompatibility and e...Self-assembling peptides （SAPs） are synthetic bioinspired biomaterials that can be feasibly multi-functionalized for cell transplantation and/or drug delivery therapies. Despite their superior biocompatibility and ease of scaling-up for production, they are unfortunately hampered by weak mechanical properties due to transient non-covalent interactions among and within the self-assembled peptide chains, thus limiting their potential applications as fillers, hemostat solutions, and fragile scaffolds for soft tissues. Here, we have developed and characterized a cross-linking strategy that increases both the stiffness and the tailorability of SAP hydrogels, enabling the preparation of transparent flexible threads, discs, channels, and hemispherical constructs. Empirical and computational results, in close agreement with each other, confirmed that the cross-linking reaction does not affect the previously self-assembled secondary structures. In vitro tests also provided a first hint of satisfactory biocompatibility by favoring viability and differentiation of human neural stem cells. This work could bring self-assembling peptide technology to many applications that have been precluded so far, especially in regenerative medicine.展开更多
Viral vector gene delivery is a promising technique for the therapeutic administra- tion of proteins to damaged tissue for the improvement of regeneration outcomes in various disease settings including brain and spina...Viral vector gene delivery is a promising technique for the therapeutic administra- tion of proteins to damaged tissue for the improvement of regeneration outcomes in various disease settings including brain and spinal cord injury, as well as autoimmune diseases. Though promising results have been demonstrated, limitations of viral vectors, including spread of the virus to distant sites, neutralization by the host immune system, and low transduction efficiencies have stimulated the investigation of biomaterials as gene delivery vehicles for improved protein expression at an injury site. Here, we show how N- fluorenylmethyloxycarbonyl （Fmoc） self-assembling peptide （SAP） hydrogels, designed for tissue-specific central nervous system （CNS） applications via incorporation of the laminin peptide sequence isoleucine-lysine-valine-alanine- valine （IKVAV）, are effective as biocompatible, localized viral vector gene delivery vehicles in vivo. Through the addition of a C-terminal lysine （K） residue, we show that increased electrostatic interactions, provided by the additional amine side chain, allow effective immobilization of lentiviral vector particles, thereby limiting their activity exclusively to the site of injection and enabling focal gene delivery in vivo in a tissue-specific manner. When the C-terminal lysine was absent, no difference was observed between the number of transfected cells, the volume of tissue transfected, or the transfection efficiency with and without the Fmoc-SAP. Importantly, immobilization of the virus only affected transfection cell number and volume, with no impact observed on transfection efficiency. This hydrogel allows the sustained and targeted delivery of growth factors post injury. We have established Fmoc-SAPs as a versatile platform for enhanced biomaterial design for a range of tissue engineering applications.展开更多
A clear understanding on cell migration behaviors contributes to designing novel biomaterials in tissue engineering and elucidating related tissue regeneration processes. Many traditional evaluation methods on cell mi...A clear understanding on cell migration behaviors contributes to designing novel biomaterials in tissue engineering and elucidating related tissue regeneration processes. Many traditional evaluation methods on cell migration including scratch assay and transwell migration assay possess all kinds of limitations.In this study, a novel honeycomb cell assay kit was designed and made of photosensitive resin by 3D printing. This kit has seven hexagonal culture chambers so that it can evaluate the horizontal cell migration behavior in response to six surrounding environments simultaneously, eliminating the effect of gravity on cells. Here this cell assay kit was successfully applied to evaluate endothelial cell migration cultured on self-assembling peptide （SAP） RADA （AcN-RADARADARADARADA-CONH2） nanofiber hydrogel toward different functionalized SAP hydrogels. Our results indicated that the functionalized RADA hydrogels with different concentration of bioactive motifs of KLT or PRG could induce cell migration in a dose-dependent manner. The total number and migration distance of endothelial cells on functionalized SAP hydrogels significantly increased with increasing concentration of bioactive motif PRG or KLT. Therefore, the honeycomb cell assay kit provides a simple, efficient and convenient tool to investigate cell migration behavior in response to multi-environments simultaneously.展开更多
Developing novel building blocks with predictable side-chain orientations and minimal intramolecular interactions is essential for peptide-based self-assembling materials.Traditional structures likeα-helices andβ-sh...Developing novel building blocks with predictable side-chain orientations and minimal intramolecular interactions is essential for peptide-based self-assembling materials.Traditional structures likeα-helices andβ-sheets rely on such interactions for stability,limiting control over exposed interacting moieties.Here,we reported a novel,frame-like peptide scaffold that maintains exceptional stability without intramolecular interactions.This structure exposes its backbone and orients side chains for hierarchical self-assembly into micron-scale cubes.By introducing mutations at specific sites,we controlled packing orientations,offering new options for tunable self-assembly.Our scaffold provides a versatile platform for designing advanced peptide materials,with applications in nanotechnology and biomaterials.展开更多
The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the p...The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the phosphatase-based enzyme-instructed self-assembly(EISA)to supervise artificial esterases'final structures and catalytic activities.We reported that peptide precursors containing different phosphorylation sites could preorganize into alternated nanostructures and undergo dephosphorylation in the presence of alkaline phosphatase(ALP)with variation in kinetic and thermodynamic profiles.Although identical self-assembly compositions were formed after dephosphorylation,precursors with more enhanced preorganized states tended to better promote ALP dephosphorylation,facilitate further self-assembly,and strengthen the catalytic activities of the final assemblies.We envisioned that our strategy would be useful for further construction and manipulation of various artificial enzymes with superior catalytic activities.展开更多
The development of natural biomaterials applied for hard tissue repair and regeneration is of great importance,especially in societies with a large elderly population.Self-assembled peptide hydrogels are a new generat...The development of natural biomaterials applied for hard tissue repair and regeneration is of great importance,especially in societies with a large elderly population.Self-assembled peptide hydrogels are a new generation of biomaterials that provide excellent biocompatibility,tunable mechanical stability,injectability,trigger capability,lack of immunogenic reactions,and the ability to load cells and active pharmaceutical agents for tissue regeneration.Peptide-based hydrogels are ideal templates for the deposition of hydroxyapatite crystals,which can mimic the extracellular matrix.Thus,peptide-based hydrogels enhance hard tissue repair and regeneration compared to conventional methods.This review presents three major self-assembled peptide hydrogels with potential application for bone and dental tissue regeneration,including ionic self-complementary peptides,amphiphilic(surfactant-like)peptides,and triple-helix(collagen-like)peptides.Special attention is given to the main bioactive peptides,the role and importance of self-assembled peptide hydrogels,and a brief overview on molecular simulation of self-assembled peptide hydrogels applied for bone and dental tissue engineering and regeneration.展开更多
To synthesize KLD-12 peptide with sequence of AcN-KLDLKLDLKLDL-CNH2 and trigger its self-assembly in vitro, to encapsulate rabbit MSCs within peptide hydrogel for 3-D culture and to evaluate the feasibility of using i...To synthesize KLD-12 peptide with sequence of AcN-KLDLKLDLKLDL-CNH2 and trigger its self-assembly in vitro, to encapsulate rabbit MSCs within peptide hydrogel for 3-D culture and to evaluate the feasibility of using it as injectable scaffold for tissue engineering of IVD. KLD-12 peptide was purified and tested with high performance liquid chromatography （HPLC） and mass spectroscopy （MS）. KLD-12 peptide solutions with concentrations of 5 g/L, 2.5 g/L and 1 g/L were triggered to self-assembly with 1 xPBS in vitro, and the self-assembled peptide hydrogel was morphologically observed. Atomic force microscope （AFM） was employed to examine the inner structure of self-assembled peptide hydrogel. Mesenchymal stem cells （MSCs） were encapsulated within peptide hydrogel for 3-D culture for 2 weeks. Calcein-AM/PI fluorescence staining was used to detect living and dead cells. Cell viability was observed to evaluate the bioactivity of MSCs in KLD-12 peptide hydrogel. The results of HPLC and MS showed that the relative molecular mass of KLD-12 peptide was 1467.83, with a purity quotient of 95.36%. KLD-12 peptide at 5 g/L could self-assemble to produce a hydrogel, which was structurally integral and homogeneous and was able to provide sufficient cohesion to retain the shape of hydrogel. AFM demonstrated that the self-assembly of KLD-12 peptide hydrogel was successful and the assembled material was composed of a kind of nano-fiber with a diameter of 3040 nm and a length of hundreds of nm. Calcein-AM/PI fluorescence staining revealed that MSCs in KLD-12 peptide hydrogel grew well. Cell activity detection exhibited that the A value increased over the culture time. It is concluded that KLD-12 peptide was synthesized successfully and was able to self-assemble to produce nano-fiber hydrogel in vitro. MSCs in KLD-12 peptide hydrogel grew well and proliferated with the culture time. KLD-12 peptide hydrogel can serve as an excellent injectable material of biological scaffolds in tissue engineering of IVD.展开更多
文摘PuraStat®is a novel self-assembling peptide(SAP)used as a haemostatic agent in endoscopy,with widespread application in surgical settings.While the current evidence,though deserving further expansion,demonstrates a good haemostatic performance profile for this substance,there remains significant heterogeneity among studies,and an analysis of this SAP as monotherapy is not always available.The recent study by Bellester et al in the World Journal of Gastrointestinal Endoscopy provided an optimal effectiveness profile of this SAP in 45 patients treated for gastrointestinal(GI)bleeding,particularly highlighting data on its use as monotherapy in upper GI bleeding.This invited article outlines the current evidence on PuraStat®and offers a commentary on the recently published study.
基金supported by a grant from the National Key Basic Research Program of China,No.2014CB542202 and 2014CB542205the National Natural Science Foundation of China,No.30973095&81371354+2 种基金a grant from Science and Technology Project of Guangzhou,in China,No.12C32121609the Natural Science Foundation of Guangdong Province of China,No.S2013010014697 to Guo JSHong Kong SCI Fund to Wu WT
文摘In this study, we developed a novel artificial nerve graft termed self-assembling peptide nanofiber scaffold （SAPNS）-containing poly（lactic-co-glycolic acid） （PLGA） conduit （SPC） and used it to bridge a 10-mm-long sciatic nerve defect in the rat. Retrograde tracing, behavioral testing and histomorphometric analyses showed that compared with the empty PLGA conduit implantation group, the SPC implantation group had a larger number of growing and extending axons, a markedly increased diameter of regenerated axons and a greater thickness of the myelin sheath in the conduit. Furthermore, there was an increase in the size of the neuromuscular junction and myofiber diameter in the target muscle. These findings suggest that the novel artificial SPC nerve graft can promote axonal regeneration and remyelination in the transected peripheral nerve and can be used for repairing peripheral nerve injury.
基金financially supported by the National Natural Science Foundation of China(Nos.82072072,32171326 and 31800795)the International Cooperation Project by the Science and Technology Department of Sichuan Province(No.2021YFH0056)+1 种基金the Sichuan Science and Technology Program(No.2021JDRC0160)the High-level Talents Research and Development Program of Affiliated Dongguan Hospital(No.K202102)。
文摘Thrombosis is the major stumbling block to the clinical application of blood-contacting devices.Herein,a quick and easy surface engineering strategy of hydrogel coating with the therapeutic gas nitric oxide(NO)generation was reported to realize up-regulation of cyclic guanosine monophosphate(c GMP)and improve hemocompatibility for diverse metal materials.We first introduce the active centre selenocysteine of glutathione peroxidase(GPx)to the self-assembling peptide(RADA)4,obtaining a functionalized hydrogel.Then the hydrogel is directly coated on the 316L stainless steel(SS)for catalytically generating NO from endogenous s-nitrosothiols(RSNO).The generated NO endows the coated surface with regulation of platelet behavior and reduction of plasmatic coagulation activation and complement system activation,hence improving antithrombotic ability in vitro and ex vivo.Overall,our NO-generating hydrogel coating surface engineering strategy provides a novel solution to remove the obstacle about thrombosis of blood-contacting devices in clinic.
基金supported by National Basic Research Program of China(973 Program,2014CB542205)Hong Kong RGC grant+2 种基金Hong Kong Health and Medical Research Fundfoundation for Distinguished Young Talents in Higher Education of Guangdong(Yq2013023)the Leading Talents of Guangdong Province(87014002)
文摘Following injury in central nervous system（CNS）,there are pathological changes in the injured region,which include neuronal death,axonal damage and demyelination,inflammatory response and activation of glial cells.The proliferation of a large number of astrocytes results in the formation of glial scar.
基金Funded by the National Natural Science Foundation of China (No.30571873)
文摘The effect of culture in KLD-12 self-assembling peptide nanofiber scaffold containing TGF-β3 gene on differentiation of precartilaginous stem cells （PSCs） into chondrocytes was studied. KLD-12 was synthesized by solid-state method. After TGF-β3 plasmid was loaded into KLD-12 self-assembling peptide nanofiber scaffold, DNA release ability was investigated. PSCs and hTGF-β3 gene were loaded into KLD-12 3-D scaffold, and MTT assay was performed to investigate the cell proliferation, and ELASA assay was used to investigate the expression of TGF-β3. Specific cartilage matrix was examined by quantitative real-time PCR, immunohistochemistry and Alcian Blue staining. Compared with control group, DNA synthesis level of PSCs reached the peak within 3 days when PSCs were cultured in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, and maintained this high level within 2 weeks. MTT results showed that the proliferation ability of experimental group was statistically higher than that in control group （P〈0.05）. Quantitative real-time PCR suggested that the percentage of TGF-β3 positive PSCs in experimental group was higher than that in control group （P〈0.01）. ELISA assay showed that the TGF-β3 protein level increased in supernatant of experimental group＇s PSCs, reached the peak after 72 h and then declined a little to the plateau phase. Compared with the control group, the specific gene of chondrocyte typical extracellular matrix significantly up-regulated （P〈0.01）. The results showed that PSCs differentiated into chondrocytes in self-assembling peptide nanofiber scaffold loading TGF-β3 plasmid, which provided a fresh approach to cartilage tissue engineering.
基金the National Natural Science Foundation of China(Nos.51890891,51725302,21807020,51573031 and 51573032)National Key R&D Program of China(No.2018YFE0205400)Science Fund for Creative Research Groups of the National Natural Science Foundation of China(No.11621505)。
文摘Vascular endothelial growth factor(VEGF)-vascular endothelial growth factor receptor(VEGFR)pathways are essential in tumor angiogenesis,growth and metastasis.Studies on anti-angiogenic therapy have been mostly focused on the blockage of VEGF-VEGFR pathways.We report an extracellularly transformable peptide-based nanomaterial to develop artificial extracellular matrix(ECM)-like networks for high-efficient blockage of natural VEGF-VEGFR interactions.The transformable peptide-based nanomaterial transforms from nanoparticles into nanofibers upon binding to VEGFR in solution.In addition,the transformable peptide-based nanomate rial forms ECM-like fibrous netwo rks on VEGFR overexpressed cells,inhibiting the VEGF-VEGFR interactions and the subsequent angiogenesis.The tube formation is reduced by nearly 85.1% after treatment.This strategy shows excellent potential for anti-angiogenesis,and inhibition of tumor invasion and metastasis.
基金the Program Funded by the University for Fostering Distinguished Young Scholarsthe National Natural Science Foundation of China(No.51763019,U1832125)+3 种基金the China Postdoctoral Science Foundation(No.2018M630937)the Grassland Talents Program of Inner Mongolia Autonomous Regionthe Distinguished Young Scholars Foundation of Inner Mongolia Autonomous Regionthe Young Leading Talents of Science and Technology Program of Inner Mongolia Autonomous Region
文摘Nanostructures/patterns formed by biomolecules can produce different physicochemical properties in terms of hydrophobicity, zeta-potential, color, etc., which play paramount roles in life. Peptides, as the main bio-building blocks, can form nanostructures with different functions,either in solutions or on interfaces. Previously, we synthesized a short peptide with the inspiration of an Alzheimer’s disease-related peptide: amyloid β peptide(A-p),namely GAV-9, which can epitaxially self-assemble into regular nanofilaments on liquid-solid interfaces, and it was found that both the hydrophobicity and charge state of the interfaces can significantly influence its assembling behavior. It was also reported that another A-β-containing dipeptide, FF,can self-assemble into nanostructures in solutions. Owing to the close relationship between these two short peptides, it is interesting to conjugate them into a de novo peptide with two separated structural domains and study its self-assembling behavior. To this end, herein we have synthesized the GAV-FF peptide with a sequence of NH2-VGGAVVAGVFF-CONH2 and verified its selfassembling property using the in situ liquid-phase atomic force microscopy. The results show that the GAV-FF peptide can self-assemble into nanofilaments both in solutions and on aqueous-solid interfaces, but with different morphologies. The FF domain accelerates the template-assisted self-assembling(TASA) process of the GAV domain, which in return enhances the solubility of FF in aqueous solutions and further participates in the fibrillization of FF. The current results could help deepen the understanding of the aggregation mechanism of diseaserelated peptides and could also shed light on the strategies to create artificial bio-functional nanostructures/patterns,which hold a significant potential for biomedical applications.
基金Supported by the National Natural Science Foundation of China(Nos.51003065 and 81000658)New Teachers’Fund for Doctor Stations,and Ministry of Education(No.20100181120077)
文摘The potential application of a designed self-assembly peptide CH3CO-Pro-Thr-Phe-CysPhe-Lys-Phe-Glu-Pro-NH2（named as P1） as a carrier of 5-Fluorouracil（5-Fu） for controlled release in vitro was studied. 5-Fluorouracil（5-Fu） was selected as a representative anticancer drug due to its extensive use in treating digestive system cancer and breast cancer. The interaction between P1 and 5-Fu was detected by fluorescent quenching experiments and atomic force microscopy（AFM）. The quenching mechanism of 5-Fu and P1 system was dynamic by performing fluorescent quenching experiments at different temperatures. The thermodynamic analysis demonstrated that the interaction between 5-Fu and P1 was hydrophobic interaction. The complexes prepared by the interaction between peptide and 5-Fu appeared as large granular particles of about 20 nm in height under AFM（denoted as5-Fu-P1）, 24 times larger than the original 5-Fu particles. According to the results, an interaction model was proposed. Furthermore, 5-Fu-P1 complexes exhibited an efficient controlled release of 5-Fu in vitro. The research suggested that P1 might be a candidate carrier for drug delivery, providing a substitution agent for 5-Fu.
基金supported by the National Key R&D Program of China(No.2022YFC2304202)the National Natural Science Foundation of China(32171325,32201094)+2 种基金the Shenzhen Science and Technology Program(KQTD20240729102037042)Soft Science Research Program of Zhejiang Province(2023C15012)the Natural Science Foundation of Tianjin(22JCZDJC00280,23JCZDJC01020).
文摘Androgenetic alopecia(AGA),the most prevalent form of hair loss,urgently requires breakthroughs in existing therapies due to limitations such as medication side effects,recurrence risks,and treatment inefficacy.Herein,we propose an insulin-derived self-assembling sequence Ac-GFFY,combined with the C domain peptide of insulin-like growth factor 1,successfully designing an IGF-1 biomimetic peptide factor,Ac-GFFY-IGF,which can substitute for the absent IGF-1 in the AGA pathological environment and facilitate hair regrowth.Compared with IGF-1,Ac-GFFY-IGF exhibits superior in vitro stability and enhanced skin permeability.In the murine AGA model,Ac-GFFY-IGF demonstrated superior efficacy to the clinically used minoxidil,achieving faster hair regeneration,higher hair quality,and broader hair coverage at lower concentrations.Our strategy provides a critical theoretical foundation and technical pathway for developing novel mechanism-driven therapies for AGA.
基金the financial support from the National Key R&D Program of China(No.2020YFC1107600,2018YFB0704304,and 2018YFB1105504)Shandong Province Key R&D Program of China(No.2019JZZY011106)+3 种基金the National Natural Science Foundation of China(No.31771056 and 31800813)the Key Laboratory of Trauma and Neural Regeneration(Peking University),the Ministry of Education(No.BMU2019XY007-01)the Ministry of Education Innovation Program of China(No.IRT_16R01)Shenzhen Science and Technology Program(No.20190806162205278).
文摘Nerve guidance conduits with hollow lumen fail to regenerate critical-sized peripheral nerve defects(15 mm in rats and 25 mm in humans),which can be improved by a beneficial intraluminal microenvironment.However,individual cues provided by intraluminal filling materials are inadequate to eliminate the functional gap between regenerated nerves and normal nerves.Herein,an aligned fibrin/functionalized self-assembling peptide(AFG/fSAP)interpenetrating nanofiber hydrogel that exerting synergistic topographical and biochemical cues for peripheral nerve regeneration is constructed via electrospinning and molecular self-assembly.The hydrogel possesses an aligned structure,high water content,appropriate mechanical properties and suitable biodegradation capabilities for nerve repair,which enhances the alignment and neurotrophin secretion of primary Schwann cells(SCs)in vitro,and successfully bridges a 15-mm sciatic nerve gap in rats in vivo.The rats transplanted with the AFG/fSAP hydrogel exhibit satisfactory morphological and functional recovery in myelinated nerve fibers and innervated muscles.The motor function recovery facilitated by the AFG/fSAP hydrogel is comparable with that of autografts.Moreover,the AFG/fSAP hydrogel upregulates the regeneration-associated gene expression and activates the PI3K/Akt and MAPK signaling pathways in the regenerated nerve.Altogether,the AFG/fSAP hydrogel represents a promising approach for peripheral nerve repair through an integration of structural guidance and biochemical stimulation.
文摘Nerve guidance conduit （NGC） is a potential alternative to autologous nerve for peripheral nerve regeneration. A promising therapeutic strategy is to modify the nerve guidance conduit intraluminal microenvironment using physical and/or chemical guidance cues. In this study, a neurotrophic peptide-functionalized self-assembling peptide nanofiber hydrogel that could promote PC12 cell adhesion, proliferation, and neuronal differentiation in vitro was prefilled in the lumen of a hollow chitosan tube （hCST） to accelerate axonal regeneration in a rat sciatic nerve defect model. The functionalized self-assembling peptide was developed by introducing a neurotrophic peptide （RGI, RGIDKRHWNSQ） derived from brain-derived neurotrophic factor （BDNF） to the C-terminus of the self-assembling peptide RADA16-I （Ac-（RADA）4-CONH2）. Morphological, histological, electrophysiological, and functional analyses demonstrated that the RGI-functionalized, self-assembling, peptide nanofiber hydrogel RAD/RGI could produce a neurotrophic microenvironment that markedly improved axonal regeneration with enhanced re-myelination and motor functional recovery.
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Acknowledgements This work was supported by the National Natural Science Foundation of China （Grant Nos. 51303119 and 51203108）, Natural Science Foundation of Jiangsu Province （BK20130309, BK201341421, BK2011355）, Natural Science Foundation of the Jiangsu Higher Education Institutions （13KJB430019）, National Science Foundation for Post-doctoral Scientists of China （2013M541724 and 2014T70545）, Tsinghua University Initiative Scientific Research Program （20121087982）, and 973 Program （2011CB606205）.
文摘Central nervous system （CNS） presents a complex regeneration problem due to the inability of central neurons to regenerate correct axonal and dendritic connections. However, recent advances in developmental neurobiology, cell signaling, cell-matrix interaction, and biomaterials technologies have forced a reconsideration of CNS regeneration potentials from the viewpoint of tissue engineering and regenerative medicine. The applications of a novel tissue regeneration-inducing biomaterial and stem cells are thought to be critical for the mission. The use of peptide nanoflber hydrogels in cell therapy and tissue engineering offers promising perspectives for CNS regeneration. Self-assembling peptide undergo a rapid transformation from liquid to gel upon addition of counterions or pH adjustment, directly integrating with the host tissue. The peptide nanofiber hydrogels have mechanical properties that closely match the native central nervous extracellular matrix, which could enhance axonal growth. Such materials can provide an optimal three dimensional microenvironment for encapsulated cells. These materials can also be tailored with bioactive motifs to modulate the wound environment and enhance regeneration. This review intends to detail the recent status of selfassembling peptide nanoflber hydrogels for CNS regeneration.
文摘Self-assembling peptides （SAPs） are synthetic bioinspired biomaterials that can be feasibly multi-functionalized for cell transplantation and/or drug delivery therapies. Despite their superior biocompatibility and ease of scaling-up for production, they are unfortunately hampered by weak mechanical properties due to transient non-covalent interactions among and within the self-assembled peptide chains, thus limiting their potential applications as fillers, hemostat solutions, and fragile scaffolds for soft tissues. Here, we have developed and characterized a cross-linking strategy that increases both the stiffness and the tailorability of SAP hydrogels, enabling the preparation of transparent flexible threads, discs, channels, and hemispherical constructs. Empirical and computational results, in close agreement with each other, confirmed that the cross-linking reaction does not affect the previously self-assembled secondary structures. In vitro tests also provided a first hint of satisfactory biocompatibility by favoring viability and differentiation of human neural stem cells. This work could bring self-assembling peptide technology to many applications that have been precluded so far, especially in regenerative medicine.
文摘Viral vector gene delivery is a promising technique for the therapeutic administra- tion of proteins to damaged tissue for the improvement of regeneration outcomes in various disease settings including brain and spinal cord injury, as well as autoimmune diseases. Though promising results have been demonstrated, limitations of viral vectors, including spread of the virus to distant sites, neutralization by the host immune system, and low transduction efficiencies have stimulated the investigation of biomaterials as gene delivery vehicles for improved protein expression at an injury site. Here, we show how N- fluorenylmethyloxycarbonyl （Fmoc） self-assembling peptide （SAP） hydrogels, designed for tissue-specific central nervous system （CNS） applications via incorporation of the laminin peptide sequence isoleucine-lysine-valine-alanine- valine （IKVAV）, are effective as biocompatible, localized viral vector gene delivery vehicles in vivo. Through the addition of a C-terminal lysine （K） residue, we show that increased electrostatic interactions, provided by the additional amine side chain, allow effective immobilization of lentiviral vector particles, thereby limiting their activity exclusively to the site of injection and enabling focal gene delivery in vivo in a tissue-specific manner. When the C-terminal lysine was absent, no difference was observed between the number of transfected cells, the volume of tissue transfected, or the transfection efficiency with and without the Fmoc-SAP. Importantly, immobilization of the virus only affected transfection cell number and volume, with no impact observed on transfection efficiency. This hydrogel allows the sustained and targeted delivery of growth factors post injury. We have established Fmoc-SAPs as a versatile platform for enhanced biomaterial design for a range of tissue engineering applications.
基金This research was supported by the National Natural Science Foundation of China （Grant Nos. 51572144 and 21371106） and the Tsinghua University Initiative Scientific Research Program （Grant No. 20161080091）.
文摘A clear understanding on cell migration behaviors contributes to designing novel biomaterials in tissue engineering and elucidating related tissue regeneration processes. Many traditional evaluation methods on cell migration including scratch assay and transwell migration assay possess all kinds of limitations.In this study, a novel honeycomb cell assay kit was designed and made of photosensitive resin by 3D printing. This kit has seven hexagonal culture chambers so that it can evaluate the horizontal cell migration behavior in response to six surrounding environments simultaneously, eliminating the effect of gravity on cells. Here this cell assay kit was successfully applied to evaluate endothelial cell migration cultured on self-assembling peptide （SAP） RADA （AcN-RADARADARADARADA-CONH2） nanofiber hydrogel toward different functionalized SAP hydrogels. Our results indicated that the functionalized RADA hydrogels with different concentration of bioactive motifs of KLT or PRG could induce cell migration in a dose-dependent manner. The total number and migration distance of endothelial cells on functionalized SAP hydrogels significantly increased with increasing concentration of bioactive motif PRG or KLT. Therefore, the honeycomb cell assay kit provides a simple, efficient and convenient tool to investigate cell migration behavior in response to multi-environments simultaneously.
基金supported by the National Basic Research Program of China 973 Program(Nos.2021YFA0910803,2021YFC2103900)the National Natural Science Foundation of China(No.21977011)+4 种基金the Natural Science Foundation of Guangdong Province(Nos.2022A1515010996 and 2020A1515011544)the Shenzhen Science and Technology Innovation Committee(Nos.RCJC20200714114433053,JCYJ20180507181527112 and JCYJ20200109140406047)the Shenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research Institutions(No.2019SHIBS0004)the Shenzhen Fundamental Research Program(No.GXWD20201231165807007–20200827170132001)Tian Fu Jin Cheng Laboratory(Advanced Medical Center)Group Racing Project(No.TFJC2023010008)。
文摘Developing novel building blocks with predictable side-chain orientations and minimal intramolecular interactions is essential for peptide-based self-assembling materials.Traditional structures likeα-helices andβ-sheets rely on such interactions for stability,limiting control over exposed interacting moieties.Here,we reported a novel,frame-like peptide scaffold that maintains exceptional stability without intramolecular interactions.This structure exposes its backbone and orients side chains for hierarchical self-assembly into micron-scale cubes.By introducing mutations at specific sites,we controlled packing orientations,offering new options for tunable self-assembly.Our scaffold provides a versatile platform for designing advanced peptide materials,with applications in nanotechnology and biomaterials.
基金supported by the National Science Fund for Distinguished Young Scholars(31825012)the National Natural Science Foundation of China(21875116,31961143004,81921004)+1 种基金the National Key Research and Development Program of China(2017YFC1103502,2018YFC1003401)the China Postdoctoral Science Foundation(2020M680856)。
文摘The creation of artificial enzymes to mimic natural enzymes remains a great challenge owing to the complexity of the structural arrangement of the essential amino acids in catalytic centers.In this study,we used the phosphatase-based enzyme-instructed self-assembly(EISA)to supervise artificial esterases'final structures and catalytic activities.We reported that peptide precursors containing different phosphorylation sites could preorganize into alternated nanostructures and undergo dephosphorylation in the presence of alkaline phosphatase(ALP)with variation in kinetic and thermodynamic profiles.Although identical self-assembly compositions were formed after dephosphorylation,precursors with more enhanced preorganized states tended to better promote ALP dephosphorylation,facilitate further self-assembly,and strengthen the catalytic activities of the final assemblies.We envisioned that our strategy would be useful for further construction and manipulation of various artificial enzymes with superior catalytic activities.
文摘The development of natural biomaterials applied for hard tissue repair and regeneration is of great importance,especially in societies with a large elderly population.Self-assembled peptide hydrogels are a new generation of biomaterials that provide excellent biocompatibility,tunable mechanical stability,injectability,trigger capability,lack of immunogenic reactions,and the ability to load cells and active pharmaceutical agents for tissue regeneration.Peptide-based hydrogels are ideal templates for the deposition of hydroxyapatite crystals,which can mimic the extracellular matrix.Thus,peptide-based hydrogels enhance hard tissue repair and regeneration compared to conventional methods.This review presents three major self-assembled peptide hydrogels with potential application for bone and dental tissue regeneration,including ionic self-complementary peptides,amphiphilic(surfactant-like)peptides,and triple-helix(collagen-like)peptides.Special attention is given to the main bioactive peptides,the role and importance of self-assembled peptide hydrogels,and a brief overview on molecular simulation of self-assembled peptide hydrogels applied for bone and dental tissue engineering and regeneration.
基金supported by a"863"Key Project of the High Technology Research and Development Program of China(No.2006AA02A124)
文摘To synthesize KLD-12 peptide with sequence of AcN-KLDLKLDLKLDL-CNH2 and trigger its self-assembly in vitro, to encapsulate rabbit MSCs within peptide hydrogel for 3-D culture and to evaluate the feasibility of using it as injectable scaffold for tissue engineering of IVD. KLD-12 peptide was purified and tested with high performance liquid chromatography （HPLC） and mass spectroscopy （MS）. KLD-12 peptide solutions with concentrations of 5 g/L, 2.5 g/L and 1 g/L were triggered to self-assembly with 1 xPBS in vitro, and the self-assembled peptide hydrogel was morphologically observed. Atomic force microscope （AFM） was employed to examine the inner structure of self-assembled peptide hydrogel. Mesenchymal stem cells （MSCs） were encapsulated within peptide hydrogel for 3-D culture for 2 weeks. Calcein-AM/PI fluorescence staining was used to detect living and dead cells. Cell viability was observed to evaluate the bioactivity of MSCs in KLD-12 peptide hydrogel. The results of HPLC and MS showed that the relative molecular mass of KLD-12 peptide was 1467.83, with a purity quotient of 95.36%. KLD-12 peptide at 5 g/L could self-assemble to produce a hydrogel, which was structurally integral and homogeneous and was able to provide sufficient cohesion to retain the shape of hydrogel. AFM demonstrated that the self-assembly of KLD-12 peptide hydrogel was successful and the assembled material was composed of a kind of nano-fiber with a diameter of 3040 nm and a length of hundreds of nm. Calcein-AM/PI fluorescence staining revealed that MSCs in KLD-12 peptide hydrogel grew well. Cell activity detection exhibited that the A value increased over the culture time. It is concluded that KLD-12 peptide was synthesized successfully and was able to self-assemble to produce nano-fiber hydrogel in vitro. MSCs in KLD-12 peptide hydrogel grew well and proliferated with the culture time. KLD-12 peptide hydrogel can serve as an excellent injectable material of biological scaffolds in tissue engineering of IVD.
