In tissue engineering(TE),tissue-inducing scaffolds are a promising solution for organ and tissue repair owing to their ability to attract stem cells in vivo,thereby inducing endogenous tissue regeneration through top...In tissue engineering(TE),tissue-inducing scaffolds are a promising solution for organ and tissue repair owing to their ability to attract stem cells in vivo,thereby inducing endogenous tissue regeneration through topological cues.An ideal TE scaffold should possess biomimetic cross-scale structures,similar to that of natural extracellular matrices,at the nano-to macro-scale level.Although freeform fabrication of TE scaffolds can be achieved through 3D printing,this method is limited in simultaneously building multiscale structures.To address this challenge,low-temperature fields were adopted in the traditional fabrication processes,such as casting and 3D printing.Ice crystals grow during scaffold fabrication and act as a template to control the nano-and micro-structures.These microstructures can be optimized by adjusting various parameters,such as the direction and magnitude of the low-temperature field.By preserving the macro-features fabricated using traditional methods,additional micro-structures with smaller scales can be incorporated simultaneously,realizing cross-scale structures that provide a better mimic of natural organs and tissues.In this paper,we present a state-of-the-art review of three low-temperature-field-assisted fabrication methods—freeze casting,cryogenic3D printing,and freeze spinning.Fundamental working principles,fabrication setups,processes,and examples of biomedical applications are introduced.The challenges and outlook for low-temperature-assisted fabrication are also discussed.展开更多
The ability to replicate the microenvironment of the human body through the fabrication of scaffolds is a significant achievement in the biomedical field.However,the search for the ideal scaffold is still in its infan...The ability to replicate the microenvironment of the human body through the fabrication of scaffolds is a significant achievement in the biomedical field.However,the search for the ideal scaffold is still in its infancy and there are significant challenges to overcome.In the modern era,the scientific community is increasingly turned to natural substances due to their superior biological ability,lower cost,biodegradability,and lower toxicity than synthetic lab-made products.Chitosan is a well-known polysaccharide that has recently garnered a high amount of attention for its biological activities,especially in 3D bone tissue engineering.Chitosan closely matches the native tissues and thus stands out as a popular candidate for bioprinting.This review focuses on the potential of chitosan-based scaffolds for advancements and the drawbacks in bone treatment.Chitosan-based nanocomposites have exhibited strong mechanical strength,water-trapping ability,cellular interaction,and biodegradability.Chitosan derivatives have also encouraged and provided different routes for treatment and enhanced biological activities.3D tailored bioprinting has opened new doors for designing and manufacturing scaffolds with biological,mechanical,and topographical properties.展开更多
The field of bone tissue engineering has experienced an increase in prevalence due to the inherent challenge of the natural regeneration of significant bone deformities.This investigation focused on the preparation of...The field of bone tissue engineering has experienced an increase in prevalence due to the inherent challenge of the natural regeneration of significant bone deformities.This investigation focused on the preparation of Three-Dimensional(3D)-printed Polycaprolactone(PCL)scaffolds with varying proportions of Nanohydroxyapatite(NHA)and Nanoclay(NC),and their physiochemical and biological properties were assessed.The mechanical properties of PCL are satisfactory;however,its hydrophobic nature and long-term degradation hinder its use in scaffold fabrication.NHA and NC have been employed to improve the hydrophilic characteristics,mechanical strength,adhesive properties,biocompatibility,biodegradability,and osteoconductive behavior of PCL.The morphology results demonstrated 3D-printed structures with interconnected rectangular macropores and proper nanoparticle distribution.The sample containing 70 wt%NC showed the highest porosity(65.98±2.54%),leading to an increased degradation rate.The compressive strength ranged from 10.65±1.90 to 84.93±9.93 MPa,which is directly proportional to the compressive strength of cancellous bone(2–12 MPa).The wettability,water uptake,and biodegradability of PCL scaffolds considerably improved as the amount of NC increased.The results of the cellular assays exhibited increased proliferation,viability,and adhesion of MG-63 cells due to the addition of NHA and NC to the scaffolds.Finally,according to the in vitro results,it can be concluded that 3D-printed samples with higher amounts of NC can be regarded as a suitable scaffold for expediting the regeneration process of bone defects.展开更多
Bone damage caused by trauma and tumors is a serious problem for human health, therefore, three-dimensional (3D) scaffolding materials that stimulate and promote the regeneration of broken bone tissues have become the...Bone damage caused by trauma and tumors is a serious problem for human health, therefore, three-dimensional (3D) scaffolding materials that stimulate and promote the regeneration of broken bone tissues have become the focus of current research in the field of bone damage repair.To this regard, a preferential combination of materials and preparation techniques is considered crucial for the preparation of advanced bone tissue engineering scaffolds to better facilitate the regeneration of broken bone.In this review, current research advances and challenges in bone tissue engineering scaffolds are discussed and analyzed in detail.First, we elucidated the structure and self-healing mechanism of bone tissue.Subsequently, the main applications of different materials, including inorganic and organic materials, in bone tissue engineering scaffolds are summarized.Moreover, we overview the latest research progress of the mainstream preparation strategies of bone tissue engineering scaffolds, and provide an in-depth analysis of the different advantages of each method.Finally, promising future directions and challenges of bone tissue engineering scaffolds are systematically discussed.展开更多
The intricate hierarchical structure of musculoskeletal tissues,including bone and interface tissues,necessitates the use of complex scaffold designs and material structures to serve as tissue-engineered substitutes.T...The intricate hierarchical structure of musculoskeletal tissues,including bone and interface tissues,necessitates the use of complex scaffold designs and material structures to serve as tissue-engineered substitutes.This has led to growing interest in the development of gradient bone scaffolds with hierarchical structures mimicking the extracellular matrix of native tissues to achieve improved therapeutic outcomes.Building on the anatomical characteristics of bone and interfacial tissues,this review provides a summary of current strategies used to design and fabricate biomimetic gradient scaffolds for repairing musculoskeletal tissues,specifically focusing on methods used to construct compositional and structural gradients within the scaffolds.The latest applications of gradient scaffolds for the regeneration of bone,osteochondral,and tendon-to-bone interfaces are presented.Furthermore,the current progress of testing gradient scaffolds in physiologically relevant animal models of skeletal repair is discussed,as well as the challenges and prospects of moving these scaffolds into clinical application for treating musculoskeletal injuries.展开更多
Dermal substitutes have provided a template for the regeneration and reconstruction of the dermis.However,the healed skin tissue often exhibits abnormal morphology and functionality,including scarring and inflammation...Dermal substitutes have provided a template for the regeneration and reconstruction of the dermis.However,the healed skin tissue often exhibits abnormal morphology and functionality,including scarring and inflammation.In this study,a composite bioink composed of methacrylated gelatin(GelMA)and chitosan oligosaccharide(COS)was proposed for printing a dermal scaffold using digital light processing(DLP)technology.The GelMA/COS bioink exhibited suitable porosity,swelling,degradation rate,and mechanical properties.The inclusion of COS demonstrated antibacterial effects against both Gram positive and Gram-negative bacteria,while simultaneously fostering the proliferation of human dermal fibroblasts(HDFs).Additionally,the application of COS could effectively reduce the expression levels of fibrosis-related genes,such as collagen I,collagen III,and fibronectin I.The three-dimensionally printed cell-laden dermal scaffold exhibited excellent shape fidelity and high cellular viability,facilitating the extension of HDFs along the scaffold and the simultaneous secretion of extracellular matrix proteins.Furthermore,the HDF-laden dermal scaffold transplanted into full-thickness skin defect sites in nude mice was shown to accelerate wound closure,reduce inflammation,and improve wound healing.Overall,the DLP-printed dermal scaffold provides an appealing approach for effectively treating full-thickness skin defects in clinical settings.展开更多
Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and hi...Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.展开更多
Tendon and ligament injuries represent a major orthopedic challenge with limited effective regenerative options.In an original research study by Yang et al de-veloped a tissue engineering approach combining aligned na...Tendon and ligament injuries represent a major orthopedic challenge with limited effective regenerative options.In an original research study by Yang et al de-veloped a tissue engineering approach combining aligned nanofiber scaffolds with cyclic uniaxial stretching to promote tenogenic differentiation in bone marrow-derived mesenchymal stem cells.Their results provide critical insight into how structural and mechanical cues can synergize to generate ligament-like tissue in vitro.This editorial contextualizes their findings within the broader field of ligament regeneration and highlights the translational potential of their strategy.展开更多
Tissue engineering and regenera-tive medicine have shown signifi-cant potential for repairing and regenerating damaged tissues and can be used to provide personalized treatment plans,with broad applica-tion prospects....Tissue engineering and regenera-tive medicine have shown signifi-cant potential for repairing and regenerating damaged tissues and can be used to provide personalized treatment plans,with broad applica-tion prospects.In this special issue,Bin Li’s team outlines the latest advances in minimally invasive implantable biomaterials for bone regeneration and different methods of achieving osteogenesis,with a focus on bioceramics and polymer materials and their applications in bone healing,vertebral augmenta-tion,implant fixation,tumor treatment of bone,and treatment of infections related to bone defects.Xinquan Jiang’s team constructs a novel photo-responsive multifunctional polyetheretherketone(PEEK)-based implant material(sPEEK/BP/E7)through the self-assembly of black phosphorus(BP)nanoplatelets,bioinspired poly-dopamine(PDA),and the biologically active short peptide E7 on sPEEK.The material exhibits effective osteogenic effects and good sterilization performance,providing a new idea for clinical application.展开更多
Biomedical scaffold fabrication has seen advancements in mimicking the native extracellular matrix through intricate three-dimensional(3D)structures conducive to tissue regeneration.Coiled fibrous scaffolds have emerg...Biomedical scaffold fabrication has seen advancements in mimicking the native extracellular matrix through intricate three-dimensional(3D)structures conducive to tissue regeneration.Coiled fibrous scaffolds have emerged as promising substrates owing to their ability to provide unique topographical cues.In this study,coiled poly(ε-caprolactone)(PCL)fibrous bundles were fabricated using an alginate-based composite system,and processed with 3D printing.The unique structure was obtained through the die-swell phenomenon related to the release of residual stresses from the printed strut,thereby transforming aligned PCL fibers into coiled structures.The effects of printing parameters,such as pneumatic pressure and nozzle moving speed,on fiber morphology were investigated to ensure a consistent formation of coiled PCL fibers.The resulting coiled PCL fibrous scaffold demonstrated higher activation of mechanotransduction signaling as well as upregulation of osteogenic-related genes in human adipose stem cells(hASCs),supporting its potential in bone tissue engineering.展开更多
Owing to their unique biological effects and physicochemical properties,nanomaterials have garnered substantial attention in the field of bone tissue engineering(BTE),targeting the repair and restoration of impaired b...Owing to their unique biological effects and physicochemical properties,nanomaterials have garnered substantial attention in the field of bone tissue engineering(BTE),targeting the repair and restoration of impaired bone tissue.In recent years,strategies for the design and optimization of nanomaterials through thiolation modification have been widely applied in BTE.This review concisely summarizes the categories of nanomaterials commonly used in BTE and focuses on various strategies for the modification of nanomaterials via thiolation.A multifaceted analysis of the mechanisms by which thiolated nanomaterials enhance nanomaterial-cell interactions,promote drug loading and release,and modulate osteogenic differentiation is presented.Furthermore,this review introduces biomedical applications of thiolated nanomaterials in BTE,including as scaffold components for bone regeneration,coatings for bone implants,and drug delivery systems.Finally,the future perspectives and challenges in the development of this field are discussed.Thiolation modification strategies provide a platform for developing new ideas and methods for designing nanomaterials for BTE and are expected to accelerate the development and clinical translation of novel bone repair materials.展开更多
BACKGROUND Tendon tissue engineering requires biomimetic scaffolds and mechanical cues to direct mesenchymal stem cell differentiation toward tenogenic lineages.Bone marrow-derived mesenchymal stem cells(BMSCs),aligne...BACKGROUND Tendon tissue engineering requires biomimetic scaffolds and mechanical cues to direct mesenchymal stem cell differentiation toward tenogenic lineages.Bone marrow-derived mesenchymal stem cells(BMSCs),aligned nanofiber scaffolds,and cyclic uniaxial stretching can be used to create a functional engineered ligament tissue.AIM To investigate the effects of aligned nanofiber scaffolds and cyclic stretch on BMSC tenogenesis for ligament engineering.METHODS BMSCs were cultured on aligned and random poly-lactic acid nanofiber scaffolds under static and cyclic tensile conditions(0.5 Hz,2%strain,2 hours/day)for 7 days using a mechanical loading system(CFILLOAD-300).The Ras homolog gene family(Rho)-associated coiled coil-containing kinase(ROCK)inhibitor Y27632 was applied to explore its role in tenogenic differentiation.Scaffold morphology was assessed by scanning electron microscopy,while cell morphology,viability,and alignment were evaluated via confocal microscopy with F-actin and 4’,6-diamidino-2-phenylindole staining.Tenogenic gene expression(collagen type I alpha 2,collagen type III alpha 1,tenascin C,and tenomodulin)was quantified by quantitative polymerase chain reaction,and ligament-related protein levels(collagen I,collagen III,tenascin C,and tenomodulin)were analyzed by western blot.RESULTS Scanning electron microscopy revealed that aligned scaffolds provided consistent directional structure,whereas random scaffolds displayed a disordered fiber arrangement.Confocal microscopy showed that under static conditions,BMSCs on aligned scaffolds grew parallel to fiber alignment,while those on random scaffolds grew randomly.Under cyclic tensile strain,BMSCs on both scaffold types exhibited elongation along the direction of strain,adopting a spindle-shaped morphology.Cyclic uniaxial strain enhanced cell viability and metabolic activity based on CCK-8 assay results and upregulated ligament-specific gene and protein expression on aligned scaffolds compared to static conditions.BMSCs on aligned scaffolds under tensile strain showed the highest expression of tenogenic markers,suggesting a synergistic effect of scaffold alignment and mechanical loading.ROCK inhibition with Y27632 upregulated alternative signaling pathways(focal adhesion kinase and runt-related transcription factor 2),further promoting tenogenic differentiation.CONCLUSION Aligned nanofiber scaffolds combined with cyclic tensile strain provide an optimal environment for guiding BMSC differentiation toward ligamentous lineages,as assessed by increased expression of ligament-specific markers.Mechanical stimulation(uniaxial stretching)significantly influences BMSC tenogenic differentiation,and the combined use of aligned nanofibers and tensile strain further enhances this effect.The ROCK pathway plays a regulatory role in this process,though its precise mechanisms require further investigation.展开更多
Cardiac tissue engineering aims to efficiently replace or repair injured heart tissue using scaffolds,relevant cells,or their combination.While the combination of scaffolds and relevant cells holds the potential to ra...Cardiac tissue engineering aims to efficiently replace or repair injured heart tissue using scaffolds,relevant cells,or their combination.While the combination of scaffolds and relevant cells holds the potential to rapidly remuscularize the heart,thereby avoiding the slow process of cell recruitment,the proper ex vivo cellularization of a scaffold poses a substantial challenge.First,proper diffusion of nutrients and oxygen should be provided to the cell-seeded scaffold.Second,to generate a functional tissue construct,cells can benefit from physiological-like conditions.To meet these challenges,we developed a modular bioreactor for the dynamic cellularization of full-thickness cardiac scaffolds under synchronized mechanical and electrical stimuli.In this unique bioreactor system,we designed a cyclic mechanical load that mimics the left ventricle volume inflation,thus achieving a steady stimulus,as well as an electrical stimulus with an action potential profile to mirror the cells’microenvironment and electrical stimuli in the heart.These mechanical and electrical stimuli were synchronized according to cardiac physiology and regulated by constant feedback.When applied to a seeded thick porcine cardiac extracellular matrix(pcECM)scaffold,these stimuli improved the proliferation of mesenchymal stem/stromal cells(MSCs)and induced the formation of a dense tissue-like structure near the scaffold’s surface.Most importantly,after 35 d of cultivation,the MSCs presented the early cardiac progenitor markers Connexin-43 andα-actinin,which were absent in the control cells.Overall,this research developed a new bioreactor system for cellularizing cardiac scaffolds under cardiac-like conditions,aiming to restore a sustainable dynamic living tissue that can bear the essential cardiac excitation–contraction coupling.展开更多
Tissue engineering and regenerative medicine is a new interdisciplinary subject integrating life science,material science,engineering technology,and clinical medicine.Over the last ten years,significant advancements h...Tissue engineering and regenerative medicine is a new interdisciplinary subject integrating life science,material science,engineering technology,and clinical medicine.Over the last ten years,significant advancements have been achieved in the study of biomaterials and tissue engineering.Progress in the field of tissue engineering and regenerative medicine can result in optimal tissue regeneration and effective functional reconstruction.Spinal cord injury(SCI)is the most severe complication of spinal trauma and frequently results in significant functional impairments in the lower extremities of the affected segment.Repair of SCI is a medical challenge worldwide.Advancements in tissue engineering theory and technology offer fresh opportunities for addressing SCI,as well as providing new strategies and methodologies to tackle the challenges associated with repairing and reconstructing spinal cord function.This article provides an overview of the latest developments in tissue engineering and SCI repair,focusing on biomaterials,cells,and active factors.It also introduces nine key components related to SCI and proposes innovative approaches for repairing and functionally reconstructing the injured spinal cord.展开更多
Neurovascularization serves as the prerequisite and assurance for fostering neurogenesis after peripheral nerve injury(PNI),not only contributing to the reconstruction of the regenerative neurovascular niche but also ...Neurovascularization serves as the prerequisite and assurance for fostering neurogenesis after peripheral nerve injury(PNI),not only contributing to the reconstruction of the regenerative neurovascular niche but also providing a surface and directionality for Schwann cell(SC)cords migration and axons elongation.Despite the development of nerve tissue engineering techniques has drawn increasing attention to the intervention approach for repairing nerve defects,systematic generalization summary of the efficient intervention to expedite nerve angiogenesis is still scarce.This review delves into the mechanisms by which macrophages within the nerve defect trigger angiogenesis after PNI and elucidates how the newborn vessels support nerve regeneration,and then extracts three major categories of strategies for producing vascularized nerves in vitro and in vivo from them,encompassing(1)in vitro prevascularization,(2)in vivo prevascularization,and(3)stimulation of neurovascularization in situ.Furthermore,we emphasize that the lack of accuracy for structure and spatiotemporal regulation,as well as the operational inconvenience and delayed connection to the host's nerve stumps,have stuck the existing neurovascularization technology in the preclinical stage.The successful design of a future prospective clinical vascularized nerve scaffold should be guided by a comprehensive consideration of these aspects.展开更多
Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of...Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.展开更多
Polycaprolactone(PCL)scaffolds that are produced through additive manufacturing are one of the most researched bone tissue engineering structures in the field.Due to the intrinsic limitations of PCL,carbon nanomateria...Polycaprolactone(PCL)scaffolds that are produced through additive manufacturing are one of the most researched bone tissue engineering structures in the field.Due to the intrinsic limitations of PCL,carbon nanomaterials are often investigated to reinforce the PCL scaffolds.Despite several studies that have been conducted on carbon nanomaterials,such as graphene(G)and graphene oxide(GO),certain challenges remain in terms of the precise design of the biological and nonbiological properties of the scaffolds.This paper addresses this limitation by investigating both the nonbiological(element composition,surface,degradation,and thermal and mechanical properties)and biological characteristics of carbon nanomaterial-reinforced PCL scaffolds for bone tissue engineering applications.Results showed that the incorporation of G and GO increased surface properties(reduced modulus and wettability),material crystallinity,crystallization temperature,and degradation rate.However,the variations in compressive modulus,strength,surface hardness,and cell metabolic activity strongly depended on the type of reinforcement.Finally,a series of phenomenological models were developed based on experimental results to describe the variations of scaffold’s weight,fiber diameter,porosity,and mechanical properties as functions of degradation time and carbon nanomaterial concentrations.The results presented in this paper enable the design of three-dimensional(3D)bone scaffolds with tuned properties by adjusting the type and concentration of different functional fillers.展开更多
Nonunion represents a crucial challenge in orthopedic medicine,demanding innovative solutions beyond the scope of traditional bone grafting methods.Among the various strategies available,magnesium(Mg)implants have bee...Nonunion represents a crucial challenge in orthopedic medicine,demanding innovative solutions beyond the scope of traditional bone grafting methods.Among the various strategies available,magnesium(Mg)implants have been recognized for their biocompatibility and biodegradability.However,their susceptibility to rapid corrosion and degradation has garnered notable research interest in bone tissue engineering(BTE),particularly in the development of Mg-incorporated biocomposite scaffolds.These scaffolds gradually release Mg2+,which enhances immunomodulation,osteogenesis,and angiogenesis,thus facilitating effective bone regeneration.This review presents myriad fabrication techniques used to create Mg-incorporated biocomposite scaffolds,including electrospinning,three-dimensional printing,and sol-gel synthesis.Despite these advancements,the application of Mg-incorporated biocomposite scaffolds faces challenges such as controlling the degradation rate of Mg and ensuring mechanical stability.These limitations highlight the necessity for ongoing research aimed at refining fabrication techniques to better regulate the physicochemical and osteogenic properties of scaffolds.This review provides insights into the potential of Mg-incorporated biocomposite scaffolds for BTE and the challenges that need to be addressed for their successful translation into clinical applications.展开更多
In this paper, methacrylated γ-PGA（m PGA） precursor was synthesized via reaction between γ-PGA and glycidyl methacrylate（GMA）. Hydrogels from this precursor were prepared under 365 nm ultraviolet irradiation. Th...In this paper, methacrylated γ-PGA（m PGA） precursor was synthesized via reaction between γ-PGA and glycidyl methacrylate（GMA）. Hydrogels from this precursor were prepared under 365 nm ultraviolet irradiation. The swelling behavior and mechanical properties were studied in detail as functions of the degree of substitution（DS）, precursor concentration, and environmental p H. Results showed that the crosslink density, swelling kinetics and mechanical properties of the hdyrogel could be tailored by adjusting the DS and concentration of the precursor as well as the environmental p H. Three-dimensional photo-encapsulation of swine cartilage chondrocytes and Live/Dead assay proved the cytocompatibility of the hydrogel.展开更多
Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds bas...Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECM).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative medicine.This paper provides an overview for recent progress of biomimetic natural biomaterials(BNBMs),including advances in their preparation,functionality,potential applications and future challenges.We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM.Moreover,we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications.Finally,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.展开更多
基金National Natural Science Foundation Council of China(Grant No.52305359)Hubei Provincial Natural Science Foundation of China(Grant No.2023AFB141)National Medical Products Administration Key Laboratory for Dental Materials(PKUSS20240401)。
文摘In tissue engineering(TE),tissue-inducing scaffolds are a promising solution for organ and tissue repair owing to their ability to attract stem cells in vivo,thereby inducing endogenous tissue regeneration through topological cues.An ideal TE scaffold should possess biomimetic cross-scale structures,similar to that of natural extracellular matrices,at the nano-to macro-scale level.Although freeform fabrication of TE scaffolds can be achieved through 3D printing,this method is limited in simultaneously building multiscale structures.To address this challenge,low-temperature fields were adopted in the traditional fabrication processes,such as casting and 3D printing.Ice crystals grow during scaffold fabrication and act as a template to control the nano-and micro-structures.These microstructures can be optimized by adjusting various parameters,such as the direction and magnitude of the low-temperature field.By preserving the macro-features fabricated using traditional methods,additional micro-structures with smaller scales can be incorporated simultaneously,realizing cross-scale structures that provide a better mimic of natural organs and tissues.In this paper,we present a state-of-the-art review of three low-temperature-field-assisted fabrication methods—freeze casting,cryogenic3D printing,and freeze spinning.Fundamental working principles,fabrication setups,processes,and examples of biomedical applications are introduced.The challenges and outlook for low-temperature-assisted fabrication are also discussed.
文摘The ability to replicate the microenvironment of the human body through the fabrication of scaffolds is a significant achievement in the biomedical field.However,the search for the ideal scaffold is still in its infancy and there are significant challenges to overcome.In the modern era,the scientific community is increasingly turned to natural substances due to their superior biological ability,lower cost,biodegradability,and lower toxicity than synthetic lab-made products.Chitosan is a well-known polysaccharide that has recently garnered a high amount of attention for its biological activities,especially in 3D bone tissue engineering.Chitosan closely matches the native tissues and thus stands out as a popular candidate for bioprinting.This review focuses on the potential of chitosan-based scaffolds for advancements and the drawbacks in bone treatment.Chitosan-based nanocomposites have exhibited strong mechanical strength,water-trapping ability,cellular interaction,and biodegradability.Chitosan derivatives have also encouraged and provided different routes for treatment and enhanced biological activities.3D tailored bioprinting has opened new doors for designing and manufacturing scaffolds with biological,mechanical,and topographical properties.
文摘The field of bone tissue engineering has experienced an increase in prevalence due to the inherent challenge of the natural regeneration of significant bone deformities.This investigation focused on the preparation of Three-Dimensional(3D)-printed Polycaprolactone(PCL)scaffolds with varying proportions of Nanohydroxyapatite(NHA)and Nanoclay(NC),and their physiochemical and biological properties were assessed.The mechanical properties of PCL are satisfactory;however,its hydrophobic nature and long-term degradation hinder its use in scaffold fabrication.NHA and NC have been employed to improve the hydrophilic characteristics,mechanical strength,adhesive properties,biocompatibility,biodegradability,and osteoconductive behavior of PCL.The morphology results demonstrated 3D-printed structures with interconnected rectangular macropores and proper nanoparticle distribution.The sample containing 70 wt%NC showed the highest porosity(65.98±2.54%),leading to an increased degradation rate.The compressive strength ranged from 10.65±1.90 to 84.93±9.93 MPa,which is directly proportional to the compressive strength of cancellous bone(2–12 MPa).The wettability,water uptake,and biodegradability of PCL scaffolds considerably improved as the amount of NC increased.The results of the cellular assays exhibited increased proliferation,viability,and adhesion of MG-63 cells due to the addition of NHA and NC to the scaffolds.Finally,according to the in vitro results,it can be concluded that 3D-printed samples with higher amounts of NC can be regarded as a suitable scaffold for expediting the regeneration process of bone defects.
基金financially supported by the Fundamental Research Funds for the Central Universities of China(Nos.DUT22QN203 and DUT22YG201).
文摘Bone damage caused by trauma and tumors is a serious problem for human health, therefore, three-dimensional (3D) scaffolding materials that stimulate and promote the regeneration of broken bone tissues have become the focus of current research in the field of bone damage repair.To this regard, a preferential combination of materials and preparation techniques is considered crucial for the preparation of advanced bone tissue engineering scaffolds to better facilitate the regeneration of broken bone.In this review, current research advances and challenges in bone tissue engineering scaffolds are discussed and analyzed in detail.First, we elucidated the structure and self-healing mechanism of bone tissue.Subsequently, the main applications of different materials, including inorganic and organic materials, in bone tissue engineering scaffolds are summarized.Moreover, we overview the latest research progress of the mainstream preparation strategies of bone tissue engineering scaffolds, and provide an in-depth analysis of the different advantages of each method.Finally, promising future directions and challenges of bone tissue engineering scaffolds are systematically discussed.
基金supported by the National Natural Science Foundation of China(Grant No.52473121,52403370 and 52221006)Fundamental Research Funds for the Central Universities(buctrc202020,buctrc202312).
文摘The intricate hierarchical structure of musculoskeletal tissues,including bone and interface tissues,necessitates the use of complex scaffold designs and material structures to serve as tissue-engineered substitutes.This has led to growing interest in the development of gradient bone scaffolds with hierarchical structures mimicking the extracellular matrix of native tissues to achieve improved therapeutic outcomes.Building on the anatomical characteristics of bone and interfacial tissues,this review provides a summary of current strategies used to design and fabricate biomimetic gradient scaffolds for repairing musculoskeletal tissues,specifically focusing on methods used to construct compositional and structural gradients within the scaffolds.The latest applications of gradient scaffolds for the regeneration of bone,osteochondral,and tendon-to-bone interfaces are presented.Furthermore,the current progress of testing gradient scaffolds in physiologically relevant animal models of skeletal repair is discussed,as well as the challenges and prospects of moving these scaffolds into clinical application for treating musculoskeletal injuries.
基金supported by the National Natural Science Foundation of China(Nos.51975400 and 62031022)the Shanxi Provincial Key Medical Scientific Research Project(No.2020XM06)+2 种基金the Shanxi Provincial Basic Research Project(Nos.202103021221006,20210302123040,and 202103021223069)the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2021L044)the Shanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SX-TD026).
文摘Dermal substitutes have provided a template for the regeneration and reconstruction of the dermis.However,the healed skin tissue often exhibits abnormal morphology and functionality,including scarring and inflammation.In this study,a composite bioink composed of methacrylated gelatin(GelMA)and chitosan oligosaccharide(COS)was proposed for printing a dermal scaffold using digital light processing(DLP)technology.The GelMA/COS bioink exhibited suitable porosity,swelling,degradation rate,and mechanical properties.The inclusion of COS demonstrated antibacterial effects against both Gram positive and Gram-negative bacteria,while simultaneously fostering the proliferation of human dermal fibroblasts(HDFs).Additionally,the application of COS could effectively reduce the expression levels of fibrosis-related genes,such as collagen I,collagen III,and fibronectin I.The three-dimensionally printed cell-laden dermal scaffold exhibited excellent shape fidelity and high cellular viability,facilitating the extension of HDFs along the scaffold and the simultaneous secretion of extracellular matrix proteins.Furthermore,the HDF-laden dermal scaffold transplanted into full-thickness skin defect sites in nude mice was shown to accelerate wound closure,reduce inflammation,and improve wound healing.Overall,the DLP-printed dermal scaffold provides an appealing approach for effectively treating full-thickness skin defects in clinical settings.
基金supported by the Innovative Research Group Project of the National Natural Science Foundation of China(T2121004)Key Programme(52235007)National Outstanding Youth Foundation of China(52325504).
文摘Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.
基金Supported by Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education,No.NRF-2022R1I1A1A01068652.
文摘Tendon and ligament injuries represent a major orthopedic challenge with limited effective regenerative options.In an original research study by Yang et al de-veloped a tissue engineering approach combining aligned nanofiber scaffolds with cyclic uniaxial stretching to promote tenogenic differentiation in bone marrow-derived mesenchymal stem cells.Their results provide critical insight into how structural and mechanical cues can synergize to generate ligament-like tissue in vitro.This editorial contextualizes their findings within the broader field of ligament regeneration and highlights the translational potential of their strategy.
文摘Tissue engineering and regenera-tive medicine have shown signifi-cant potential for repairing and regenerating damaged tissues and can be used to provide personalized treatment plans,with broad applica-tion prospects.In this special issue,Bin Li’s team outlines the latest advances in minimally invasive implantable biomaterials for bone regeneration and different methods of achieving osteogenesis,with a focus on bioceramics and polymer materials and their applications in bone healing,vertebral augmenta-tion,implant fixation,tumor treatment of bone,and treatment of infections related to bone defects.Xinquan Jiang’s team constructs a novel photo-responsive multifunctional polyetheretherketone(PEEK)-based implant material(sPEEK/BP/E7)through the self-assembly of black phosphorus(BP)nanoplatelets,bioinspired poly-dopamine(PDA),and the biologically active short peptide E7 on sPEEK.The material exhibits effective osteogenic effects and good sterilization performance,providing a new idea for clinical application.
基金supported by the‘Korea National Institute of Health’research project(2022ER130502)a grant from by SMC-SKKU Future Convergence Academic Research Program,2024supported by the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(RS-2024-00336758)。
文摘Biomedical scaffold fabrication has seen advancements in mimicking the native extracellular matrix through intricate three-dimensional(3D)structures conducive to tissue regeneration.Coiled fibrous scaffolds have emerged as promising substrates owing to their ability to provide unique topographical cues.In this study,coiled poly(ε-caprolactone)(PCL)fibrous bundles were fabricated using an alginate-based composite system,and processed with 3D printing.The unique structure was obtained through the die-swell phenomenon related to the release of residual stresses from the printed strut,thereby transforming aligned PCL fibers into coiled structures.The effects of printing parameters,such as pneumatic pressure and nozzle moving speed,on fiber morphology were investigated to ensure a consistent formation of coiled PCL fibers.The resulting coiled PCL fibrous scaffold demonstrated higher activation of mechanotransduction signaling as well as upregulation of osteogenic-related genes in human adipose stem cells(hASCs),supporting its potential in bone tissue engineering.
基金financially supported by the National Natural Science Foundation of China(Nos.52103184 and 8226030956)the National Key Research and Development Program of China(No.2022YFC2407503)+3 种基金Key Project of the Natural Science Basic Research Plan of Shaanxi Province(No.2022JZ43)Natural Science Basic Research Program of Shaanxi Province(No.2024JCYBQN-0874)Medical Research Key Project of Xi'an Science and Technology Bureau(No.2024JH-YXZD-0055)Medical Research Project of Xi'an Science and Technology Bureau(No.22YXYJ0083)
文摘Owing to their unique biological effects and physicochemical properties,nanomaterials have garnered substantial attention in the field of bone tissue engineering(BTE),targeting the repair and restoration of impaired bone tissue.In recent years,strategies for the design and optimization of nanomaterials through thiolation modification have been widely applied in BTE.This review concisely summarizes the categories of nanomaterials commonly used in BTE and focuses on various strategies for the modification of nanomaterials via thiolation.A multifaceted analysis of the mechanisms by which thiolated nanomaterials enhance nanomaterial-cell interactions,promote drug loading and release,and modulate osteogenic differentiation is presented.Furthermore,this review introduces biomedical applications of thiolated nanomaterials in BTE,including as scaffold components for bone regeneration,coatings for bone implants,and drug delivery systems.Finally,the future perspectives and challenges in the development of this field are discussed.Thiolation modification strategies provide a platform for developing new ideas and methods for designing nanomaterials for BTE and are expected to accelerate the development and clinical translation of novel bone repair materials.
基金Supported by Sichuan Province Science and Technology Support Program,No.2024NSFSC1292the Program of General Hospital of Western Theater Command,No.2021-XZYG-C45 and No.2021-XZYG-B32+1 种基金the Natural Science Foundation of Gansu Province,No.23JRRA538the National Natural Science Foundation of China,No.81601905.
文摘BACKGROUND Tendon tissue engineering requires biomimetic scaffolds and mechanical cues to direct mesenchymal stem cell differentiation toward tenogenic lineages.Bone marrow-derived mesenchymal stem cells(BMSCs),aligned nanofiber scaffolds,and cyclic uniaxial stretching can be used to create a functional engineered ligament tissue.AIM To investigate the effects of aligned nanofiber scaffolds and cyclic stretch on BMSC tenogenesis for ligament engineering.METHODS BMSCs were cultured on aligned and random poly-lactic acid nanofiber scaffolds under static and cyclic tensile conditions(0.5 Hz,2%strain,2 hours/day)for 7 days using a mechanical loading system(CFILLOAD-300).The Ras homolog gene family(Rho)-associated coiled coil-containing kinase(ROCK)inhibitor Y27632 was applied to explore its role in tenogenic differentiation.Scaffold morphology was assessed by scanning electron microscopy,while cell morphology,viability,and alignment were evaluated via confocal microscopy with F-actin and 4’,6-diamidino-2-phenylindole staining.Tenogenic gene expression(collagen type I alpha 2,collagen type III alpha 1,tenascin C,and tenomodulin)was quantified by quantitative polymerase chain reaction,and ligament-related protein levels(collagen I,collagen III,tenascin C,and tenomodulin)were analyzed by western blot.RESULTS Scanning electron microscopy revealed that aligned scaffolds provided consistent directional structure,whereas random scaffolds displayed a disordered fiber arrangement.Confocal microscopy showed that under static conditions,BMSCs on aligned scaffolds grew parallel to fiber alignment,while those on random scaffolds grew randomly.Under cyclic tensile strain,BMSCs on both scaffold types exhibited elongation along the direction of strain,adopting a spindle-shaped morphology.Cyclic uniaxial strain enhanced cell viability and metabolic activity based on CCK-8 assay results and upregulated ligament-specific gene and protein expression on aligned scaffolds compared to static conditions.BMSCs on aligned scaffolds under tensile strain showed the highest expression of tenogenic markers,suggesting a synergistic effect of scaffold alignment and mechanical loading.ROCK inhibition with Y27632 upregulated alternative signaling pathways(focal adhesion kinase and runt-related transcription factor 2),further promoting tenogenic differentiation.CONCLUSION Aligned nanofiber scaffolds combined with cyclic tensile strain provide an optimal environment for guiding BMSC differentiation toward ligamentous lineages,as assessed by increased expression of ligament-specific markers.Mechanical stimulation(uniaxial stretching)significantly influences BMSC tenogenic differentiation,and the combined use of aligned nanofibers and tensile strain further enhances this effect.The ROCK pathway plays a regulatory role in this process,though its precise mechanisms require further investigation.
基金funded by the Israeli Ministry of Innovation,Science and Technology(Grant No.3-11873)the Israel Science Foundation(Grant No.1563/10)+1 种基金the Randy L.and Melvin R.Berlin Family Research Center for Regenerative Medicinethe Gurwin Family Foundation.
文摘Cardiac tissue engineering aims to efficiently replace or repair injured heart tissue using scaffolds,relevant cells,or their combination.While the combination of scaffolds and relevant cells holds the potential to rapidly remuscularize the heart,thereby avoiding the slow process of cell recruitment,the proper ex vivo cellularization of a scaffold poses a substantial challenge.First,proper diffusion of nutrients and oxygen should be provided to the cell-seeded scaffold.Second,to generate a functional tissue construct,cells can benefit from physiological-like conditions.To meet these challenges,we developed a modular bioreactor for the dynamic cellularization of full-thickness cardiac scaffolds under synchronized mechanical and electrical stimuli.In this unique bioreactor system,we designed a cyclic mechanical load that mimics the left ventricle volume inflation,thus achieving a steady stimulus,as well as an electrical stimulus with an action potential profile to mirror the cells’microenvironment and electrical stimuli in the heart.These mechanical and electrical stimuli were synchronized according to cardiac physiology and regulated by constant feedback.When applied to a seeded thick porcine cardiac extracellular matrix(pcECM)scaffold,these stimuli improved the proliferation of mesenchymal stem/stromal cells(MSCs)and induced the formation of a dense tissue-like structure near the scaffold’s surface.Most importantly,after 35 d of cultivation,the MSCs presented the early cardiac progenitor markers Connexin-43 andα-actinin,which were absent in the control cells.Overall,this research developed a new bioreactor system for cellularizing cardiac scaffolds under cardiac-like conditions,aiming to restore a sustainable dynamic living tissue that can bear the essential cardiac excitation–contraction coupling.
基金supported by grants from the National Natural Science Foundation of China(92368207)the Chinese Academy of Engineering(2023-SBZD-11)the Natural Science Foundation of Jiangsu Province(BK20232023).
文摘Tissue engineering and regenerative medicine is a new interdisciplinary subject integrating life science,material science,engineering technology,and clinical medicine.Over the last ten years,significant advancements have been achieved in the study of biomaterials and tissue engineering.Progress in the field of tissue engineering and regenerative medicine can result in optimal tissue regeneration and effective functional reconstruction.Spinal cord injury(SCI)is the most severe complication of spinal trauma and frequently results in significant functional impairments in the lower extremities of the affected segment.Repair of SCI is a medical challenge worldwide.Advancements in tissue engineering theory and technology offer fresh opportunities for addressing SCI,as well as providing new strategies and methodologies to tackle the challenges associated with repairing and reconstructing spinal cord function.This article provides an overview of the latest developments in tissue engineering and SCI repair,focusing on biomaterials,cells,and active factors.It also introduces nine key components related to SCI and proposes innovative approaches for repairing and functionally reconstructing the injured spinal cord.
基金financially supported by the following programs:National Key Research and Development Program of China(No.2023YFB3813003)National Natural Science Foundation of China(Nos.82430031,82122014,82071085)+1 种基金Zhejiang Provincial Natural Science Foundation of China(No.LR21H140001)the Central Universities(No.2022FZZX01-33)。
文摘Neurovascularization serves as the prerequisite and assurance for fostering neurogenesis after peripheral nerve injury(PNI),not only contributing to the reconstruction of the regenerative neurovascular niche but also providing a surface and directionality for Schwann cell(SC)cords migration and axons elongation.Despite the development of nerve tissue engineering techniques has drawn increasing attention to the intervention approach for repairing nerve defects,systematic generalization summary of the efficient intervention to expedite nerve angiogenesis is still scarce.This review delves into the mechanisms by which macrophages within the nerve defect trigger angiogenesis after PNI and elucidates how the newborn vessels support nerve regeneration,and then extracts three major categories of strategies for producing vascularized nerves in vitro and in vivo from them,encompassing(1)in vitro prevascularization,(2)in vivo prevascularization,and(3)stimulation of neurovascularization in situ.Furthermore,we emphasize that the lack of accuracy for structure and spatiotemporal regulation,as well as the operational inconvenience and delayed connection to the host's nerve stumps,have stuck the existing neurovascularization technology in the preclinical stage.The successful design of a future prospective clinical vascularized nerve scaffold should be guided by a comprehensive consideration of these aspects.
基金The authors are thankful to Ministry of Human Resource Development(presently Ministry of Education),Government of India,New Delhi,for providing research facility by sanctioning Center of Excellence(F.No.5-6/2013-TS VII)in Tissue Engineering and Center of Excellence in Orthopedic Tissue Engineering and Rehabilitation funded by World Bank under TEQIP-II.
文摘Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering application.The present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue regeneration.We experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and differentiation.The resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3D)printing.Morphological studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural stability.The scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue engineering.The tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of gelatin.The enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue regeneration.In vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold surface.In addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3D structures,demonstrating its potential for use in bone-tissue engineering.
基金The authors wish to acknowledge Engineering and Physical Sciences Research Council(EPSRC)UK for the Global Challenges Research Fund(No.EP/R015139/1)Rosetrees Trust UK&Stoneygate Trust UK for the Enterprise Fellowship(Ref:M874).
文摘Polycaprolactone(PCL)scaffolds that are produced through additive manufacturing are one of the most researched bone tissue engineering structures in the field.Due to the intrinsic limitations of PCL,carbon nanomaterials are often investigated to reinforce the PCL scaffolds.Despite several studies that have been conducted on carbon nanomaterials,such as graphene(G)and graphene oxide(GO),certain challenges remain in terms of the precise design of the biological and nonbiological properties of the scaffolds.This paper addresses this limitation by investigating both the nonbiological(element composition,surface,degradation,and thermal and mechanical properties)and biological characteristics of carbon nanomaterial-reinforced PCL scaffolds for bone tissue engineering applications.Results showed that the incorporation of G and GO increased surface properties(reduced modulus and wettability),material crystallinity,crystallization temperature,and degradation rate.However,the variations in compressive modulus,strength,surface hardness,and cell metabolic activity strongly depended on the type of reinforcement.Finally,a series of phenomenological models were developed based on experimental results to describe the variations of scaffold’s weight,fiber diameter,porosity,and mechanical properties as functions of degradation time and carbon nanomaterial concentrations.The results presented in this paper enable the design of three-dimensional(3D)bone scaffolds with tuned properties by adjusting the type and concentration of different functional fillers.
文摘Nonunion represents a crucial challenge in orthopedic medicine,demanding innovative solutions beyond the scope of traditional bone grafting methods.Among the various strategies available,magnesium(Mg)implants have been recognized for their biocompatibility and biodegradability.However,their susceptibility to rapid corrosion and degradation has garnered notable research interest in bone tissue engineering(BTE),particularly in the development of Mg-incorporated biocomposite scaffolds.These scaffolds gradually release Mg2+,which enhances immunomodulation,osteogenesis,and angiogenesis,thus facilitating effective bone regeneration.This review presents myriad fabrication techniques used to create Mg-incorporated biocomposite scaffolds,including electrospinning,three-dimensional printing,and sol-gel synthesis.Despite these advancements,the application of Mg-incorporated biocomposite scaffolds faces challenges such as controlling the degradation rate of Mg and ensuring mechanical stability.These limitations highlight the necessity for ongoing research aimed at refining fabrication techniques to better regulate the physicochemical and osteogenic properties of scaffolds.This review provides insights into the potential of Mg-incorporated biocomposite scaffolds for BTE and the challenges that need to be addressed for their successful translation into clinical applications.
基金supported by the National Natural Science Foundation of China(No.21004080)the Program for New Century Excellent Talents in Universities(No.NCET-09-0818)of the Ministry of Education of Chinathe Fundamental Research Funds for the Central Universities(No.101GPY41)
文摘In this paper, methacrylated γ-PGA（m PGA） precursor was synthesized via reaction between γ-PGA and glycidyl methacrylate（GMA）. Hydrogels from this precursor were prepared under 365 nm ultraviolet irradiation. The swelling behavior and mechanical properties were studied in detail as functions of the degree of substitution（DS）, precursor concentration, and environmental p H. Results showed that the crosslink density, swelling kinetics and mechanical properties of the hdyrogel could be tailored by adjusting the DS and concentration of the precursor as well as the environmental p H. Three-dimensional photo-encapsulation of swine cartilage chondrocytes and Live/Dead assay proved the cytocompatibility of the hydrogel.
基金supported by the National Natural Science Foundation of China(52003113,31900950,82102334,82002313,82072444)the National Key Research&Development Program of China(2018YFC2001502,2018YFB1105705)+6 种基金the Guangdong Basic and Applied Basic Research Foundation(2021A1515010745,2020A1515110356,2023A1515011986)the Shenzhen Fundamental Research Program(JCYJ20190808120405672)the Key Program of the National Natural Science Foundation of Zhejiang Province(LZ22C100001)the Natural Science Foundation of Shanghai(20ZR1469800)the Integration Innovation Fund of Shanghai Jiao Tong University(2021JCPT03),the Science and Technology Projects of Guangzhou City(202102020359)the Zigong Key Science and Technology Plan(2022ZCNKY07).SXC thanks the financial support under the Startup Grant of the University of Chinese Academy of Sciences(WIUCASQD2021026).HW thanks the Futian Healthcare Research Project(FTWS2022013)the financial support of China Postdoctoral Science Foundation(2021TQ0118).SL thanks the financial support of China Postdoctoral Science Foundation(2022M721490).
文摘Biomimetic materials have emerged as attractive and competitive alternatives for tissue engineering(TE)and regenerative medicine.In contrast to conventional biomaterials or synthetic materials,biomimetic scaffolds based on natural biomaterial can offer cells a broad spectrum of biochemical and biophysical cues that mimic the in vivo extracellular matrix(ECM).Additionally,such materials have mechanical adaptability,micro-structure interconnectivity,and inherent bioactivity,making them ideal for the design of living implants for specific applications in TE and regenerative medicine.This paper provides an overview for recent progress of biomimetic natural biomaterials(BNBMs),including advances in their preparation,functionality,potential applications and future challenges.We highlight recent advances in the fabrication of BNBMs and outline general strategies for functionalizing and tailoring the BNBMs with various biological and physicochemical characteristics of native ECM.Moreover,we offer an overview of recent key advances in the functionalization and applications of versatile BNBMs for TE applications.Finally,we conclude by offering our perspective on open challenges and future developments in this rapidly-evolving field.
