Large-gap nerve defects require nerve guide conduits(NGCs)for complete regeneration and muscle innervation.Many NGCs have been developed using various scaffold designs and tissue engineering strategies to promote axon...Large-gap nerve defects require nerve guide conduits(NGCs)for complete regeneration and muscle innervation.Many NGCs have been developed using various scaffold designs and tissue engineering strategies to promote axon regeneration.Still,most are tubular with inadequate pore sizes and lack surface cues for nutrient transport,cell attachment,and tissue infiltration.This study developed a porous spiral NGC to address these issues using a 3D-printed thermoplastic polyurethane(TPU)fiber lattice.The lattice was functionalized with poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)electrospun aligned(aPHBV)and randomly(rPHBV)oriented nanofibers to enhance cellular activity.TPU lattices were made with 25%,35%,and 50%infill densities to create scaffolds with varied mechanical compliance.The fabricated TPU/PHBV spiral conduits had significantly higher surface areas(25%TPU/PHBV:698.97 mm^(2),35%TPU/PHBV:500.06 mm^(2),50%TPU/PHBV:327.61 mm^(2))compared to commercially available nerve conduits like Neurolac™(205.26 mm^(2)).Aligned PHBV nanofibers showed excellent Schwann cell(RSC96)adhesion,proliferation,and neurogenic gene expression for all infill densities.Spiral TPU/PHBV conduits with 25%and 35%infill densities exhibited Young’s modulus values comparable to Neurotube®and ultimate tensile strength like acellular cadaveric human nerves.A 10 mm sciatic nerve defect in Wistar rats treated with TPU/aPHBV NGCs demonstrated muscle innervation and axon healing comparable to autografts over 4 months,as evaluated by gait analysis,functional recovery,and histology.The TPU/PHBV NGC developed in this study shows promise as a treatment for large-gap nerve defects.展开更多
Large-gap peripheral nerve injuries(PNI)are often treated with autografts,allografts,or synthetic grafts to facilitate nerve regeneration,but these options are often limited in their availability or functionality.To a...Large-gap peripheral nerve injuries(PNI)are often treated with autografts,allografts,or synthetic grafts to facilitate nerve regeneration,but these options are often limited in their availability or functionality.To address these issues,we developed ionically conductive(IC)nerve guidance conduits(NGCs)of sufficient biodegrad-ability,mechanical strength,and bioactivity to support large-gap nerve regeneration.These chitosan-based NGCs release 4-aminopyridine(4-AP)from embedded halloysite nanotubes,and the NGC’s IC properties enable transcutaneous electrical stimulation(ES)without invasive electrodes.In vitro,we found scaffolds with ES+4-AP synergistically enhanced Schwann cell adhesion,proliferation,and neurotrophin secretion,significantly improving axonal growth and neurite extension.In vivo,these scaffolds in large-gap PNI boosted neurotrophin levels,myelination,nerve function,and muscle weight while promoting angiogenesis and reducing fibrosis.Upregulated Trk receptors and PI3K/Akt and MAPK pathway highlight the regenerative potential.This study advances understanding of ES-mediated regeneration and supports innovative strategies for nerve and muscu-loskeletal repair.展开更多
Peptide molecules have design flexibility,self-assembly ability,high biocompatibility,good biodegradability,and easy functionalization,which promote their applications as versatile biomaterials for tissue engineering ...Peptide molecules have design flexibility,self-assembly ability,high biocompatibility,good biodegradability,and easy functionalization,which promote their applications as versatile biomaterials for tissue engineering and biomedicine.In addition,the functionalization of self-assembled peptide nanomaterials with other additive components enhances their stimuli-responsive functions,promoting function-specific applications that induced by both internal and external stimulations.In this review,we demonstrate recent advance in the peptide molecular design,self-assembly,functional tailoring,and biomedical applications of peptide-based nanomaterials.The strategies on the design and synthesis of single,dual,and multiple stimuli-responsive peptide-based nanomaterials with various dimensions are analyzed,and the functional regulation of peptide nanomaterials with active components such as metal/metal oxide,DNA/RNA,polysaccharides,photosensitizers,2D materials,and others are discussed.In addition,the designed peptide-based nanomaterials with temperature-,pH-,ion-,light-,enzyme-,and ROS-responsive abilities for drug delivery,bioimaging,cancer therapy,gene therapy,antibacterial,as well as wound healing and dressing applications are presented and discussed.This comprehensive review provides detailed methodologies and advanced techniques on the synthesis of peptide nanomaterials from molecular biology,materials science,and nanotechnology,which will guide and inspire the molecular level design of peptides with specific and multiple functions for function-specific applications.展开更多
Tendon and ligament injuries are the most common musculoskeletal injuries,which not only impact the quality of life but result in a massive economic burden.Surgical interventions for tendon/ligament injuries utilize b...Tendon and ligament injuries are the most common musculoskeletal injuries,which not only impact the quality of life but result in a massive economic burden.Surgical interventions for tendon/ligament injuries utilize biological and/or engineered grafts to reconstruct damaged tissue,but these have limitations.Engineered matrices confer superior physicochemical properties over biological grafts but lack desirable bioactivity to promote tissue healing.While incorporating drugs can enhance bioactivity,large matrix surface areas and hydrophobicity can lead to uncontrolled burst release and/or incomplete release due to binding.To overcome these limitations,we evaluated the delivery of a peptide growth factor(exendin-4;Ex-4)using an enhanced nanofiber matrix in a tendon injury model.To overcome drug surface binding due to matrix hydrophobicity of poly(caprolactone)(PCL)-which would be expected to enhance cell-material interactions-we blended PCL and cellulose acetate(CA)and electrospun nanofiber matrices with fiber diameters ranging from 600 to 1000 nm.To avoid burst release and protect the drug,we encapsulated Ex-4 in the open lumen of halloysite nanotubes(HNTs),sealed the HNT tube endings with a polymer blend,and mixed Ex-4-loaded HNTs into the polymer mixture before electrospinning.This reduced burst release from~75%to~40%,but did not alter matrix morphology,fiber diameter,or tensile properties.We evaluated the bioactivity of the Ex-4 nanofiber formulation by culturing human mesenchymal stem cells(hMSCs)on matrix surfaces for 21 days and measuring tenogenic differentiation,compared with nanofiber matrices in basal media alone.Strikingly,we observed that Ex-4 nanofiber matrices accelerated the hMSC proliferation rate and elevated levels of sulfated glycosaminoglycan,tendon-related genes(Scx,Mkx,and Tnmd),and ECM-related genes(Col-Ⅰ,Col-Ⅲ,and Dcn),compared to control.We then assessed the safety and efficacy of Ex-4 nanofiber matrices in a full-thickness rat Achilles tendon defect with histology,marker expression,functional walking track analysis,and mechanical testing.Our analysis confirmed that Ex-4 nanofiber matrices enhanced tendon healing and reduced fibrocartilage formation versus nanofiber matrices alone.These findings implicate Ex-4 as a potentially valuable tool for tendon tissue engineering.展开更多
基金The authors wish to acknowledge Nano Mission,Department of Science&Technology(DST)(SR/NM/TP-83/2016(G))Prof.T.R.Rajagopalan R&D Cell of SASTRA Deemed University for financial and infrastructural support+4 种基金We also wish to acknowledge ATGC grant,Department of Biotechnology(DBT)(BT/ATGC/127/SP41147/2021)Adhoc funding,Indian Council of Medical Research(ICMR)(17x3/Adhoc/23/2022-ITR)DST SERB CRG(Exponential Technologies)grant(CRG/2021/007847)for financial supportfunding support provided by the National Institutes of Health(#R01NS134604,#R01EB034202,#R01AR078908,and#R01EB030060)the U.S.Army Medical Research Acquisition Activity(USAMRAA)through the CDMRP Peer-Reviewed Medical Research Program(Award No.W81XWH2010321,PR230581,and HT94252410137).
文摘Large-gap nerve defects require nerve guide conduits(NGCs)for complete regeneration and muscle innervation.Many NGCs have been developed using various scaffold designs and tissue engineering strategies to promote axon regeneration.Still,most are tubular with inadequate pore sizes and lack surface cues for nutrient transport,cell attachment,and tissue infiltration.This study developed a porous spiral NGC to address these issues using a 3D-printed thermoplastic polyurethane(TPU)fiber lattice.The lattice was functionalized with poly(3-hydroxybutyrate-co-3-hydroxyvalerate)(PHBV)electrospun aligned(aPHBV)and randomly(rPHBV)oriented nanofibers to enhance cellular activity.TPU lattices were made with 25%,35%,and 50%infill densities to create scaffolds with varied mechanical compliance.The fabricated TPU/PHBV spiral conduits had significantly higher surface areas(25%TPU/PHBV:698.97 mm^(2),35%TPU/PHBV:500.06 mm^(2),50%TPU/PHBV:327.61 mm^(2))compared to commercially available nerve conduits like Neurolac™(205.26 mm^(2)).Aligned PHBV nanofibers showed excellent Schwann cell(RSC96)adhesion,proliferation,and neurogenic gene expression for all infill densities.Spiral TPU/PHBV conduits with 25%and 35%infill densities exhibited Young’s modulus values comparable to Neurotube®and ultimate tensile strength like acellular cadaveric human nerves.A 10 mm sciatic nerve defect in Wistar rats treated with TPU/aPHBV NGCs demonstrated muscle innervation and axon healing comparable to autografts over 4 months,as evaluated by gait analysis,functional recovery,and histology.The TPU/PHBV NGC developed in this study shows promise as a treatment for large-gap nerve defects.
基金funding support provided by the National Institutes of Health(#R01NS134604,#R01EB034202,#R01AR078908,and#R01EB030060)the U.S.Army Medical Research Acquisition Activity(USAMRAA)through the CDMRP Peer-Reviewed Medical Research Program(Award No.W81XWH2010321,PR230581,and HT94252410137)the DoD support from BA230234(Award No.HT94252410944).
文摘Large-gap peripheral nerve injuries(PNI)are often treated with autografts,allografts,or synthetic grafts to facilitate nerve regeneration,but these options are often limited in their availability or functionality.To address these issues,we developed ionically conductive(IC)nerve guidance conduits(NGCs)of sufficient biodegrad-ability,mechanical strength,and bioactivity to support large-gap nerve regeneration.These chitosan-based NGCs release 4-aminopyridine(4-AP)from embedded halloysite nanotubes,and the NGC’s IC properties enable transcutaneous electrical stimulation(ES)without invasive electrodes.In vitro,we found scaffolds with ES+4-AP synergistically enhanced Schwann cell adhesion,proliferation,and neurotrophin secretion,significantly improving axonal growth and neurite extension.In vivo,these scaffolds in large-gap PNI boosted neurotrophin levels,myelination,nerve function,and muscle weight while promoting angiogenesis and reducing fibrosis.Upregulated Trk receptors and PI3K/Akt and MAPK pathway highlight the regenerative potential.This study advances understanding of ES-mediated regeneration and supports innovative strategies for nerve and muscu-loskeletal repair.
基金support from the National Natural Science Foundation of China(No.51873225)the Taishan Scholars Program of Shandong Province(No.tsqn201909104)+1 种基金the High-Grade Talents Plan of Qingdao University.Dr.Kumbar acknowledges the funding support by the National Institutes of Health(#R01NS134604,#R01EB034202,#R01AR078908,#R01EB030060 and,#R56NS122753)the U.S.Army Medical Research Acquisition Activity(USAMRAA),through the CDMRP Peer-Reviewed Medical Research Program(Award No.W81XWH2010321 and PR230581).
文摘Peptide molecules have design flexibility,self-assembly ability,high biocompatibility,good biodegradability,and easy functionalization,which promote their applications as versatile biomaterials for tissue engineering and biomedicine.In addition,the functionalization of self-assembled peptide nanomaterials with other additive components enhances their stimuli-responsive functions,promoting function-specific applications that induced by both internal and external stimulations.In this review,we demonstrate recent advance in the peptide molecular design,self-assembly,functional tailoring,and biomedical applications of peptide-based nanomaterials.The strategies on the design and synthesis of single,dual,and multiple stimuli-responsive peptide-based nanomaterials with various dimensions are analyzed,and the functional regulation of peptide nanomaterials with active components such as metal/metal oxide,DNA/RNA,polysaccharides,photosensitizers,2D materials,and others are discussed.In addition,the designed peptide-based nanomaterials with temperature-,pH-,ion-,light-,enzyme-,and ROS-responsive abilities for drug delivery,bioimaging,cancer therapy,gene therapy,antibacterial,as well as wound healing and dressing applications are presented and discussed.This comprehensive review provides detailed methodologies and advanced techniques on the synthesis of peptide nanomaterials from molecular biology,materials science,and nanotechnology,which will guide and inspire the molecular level design of peptides with specific and multiple functions for function-specific applications.
文摘Tendon and ligament injuries are the most common musculoskeletal injuries,which not only impact the quality of life but result in a massive economic burden.Surgical interventions for tendon/ligament injuries utilize biological and/or engineered grafts to reconstruct damaged tissue,but these have limitations.Engineered matrices confer superior physicochemical properties over biological grafts but lack desirable bioactivity to promote tissue healing.While incorporating drugs can enhance bioactivity,large matrix surface areas and hydrophobicity can lead to uncontrolled burst release and/or incomplete release due to binding.To overcome these limitations,we evaluated the delivery of a peptide growth factor(exendin-4;Ex-4)using an enhanced nanofiber matrix in a tendon injury model.To overcome drug surface binding due to matrix hydrophobicity of poly(caprolactone)(PCL)-which would be expected to enhance cell-material interactions-we blended PCL and cellulose acetate(CA)and electrospun nanofiber matrices with fiber diameters ranging from 600 to 1000 nm.To avoid burst release and protect the drug,we encapsulated Ex-4 in the open lumen of halloysite nanotubes(HNTs),sealed the HNT tube endings with a polymer blend,and mixed Ex-4-loaded HNTs into the polymer mixture before electrospinning.This reduced burst release from~75%to~40%,but did not alter matrix morphology,fiber diameter,or tensile properties.We evaluated the bioactivity of the Ex-4 nanofiber formulation by culturing human mesenchymal stem cells(hMSCs)on matrix surfaces for 21 days and measuring tenogenic differentiation,compared with nanofiber matrices in basal media alone.Strikingly,we observed that Ex-4 nanofiber matrices accelerated the hMSC proliferation rate and elevated levels of sulfated glycosaminoglycan,tendon-related genes(Scx,Mkx,and Tnmd),and ECM-related genes(Col-Ⅰ,Col-Ⅲ,and Dcn),compared to control.We then assessed the safety and efficacy of Ex-4 nanofiber matrices in a full-thickness rat Achilles tendon defect with histology,marker expression,functional walking track analysis,and mechanical testing.Our analysis confirmed that Ex-4 nanofiber matrices enhanced tendon healing and reduced fibrocartilage formation versus nanofiber matrices alone.These findings implicate Ex-4 as a potentially valuable tool for tendon tissue engineering.
