Oxygen Plasma Technology-Assisted Preparation of Three-Dimensional Reduced Graphene Oxide/Polypyrrole/Strontium Composite Scaffold for Repair of Bone Defects Caused by Osteoporosis

Repairs of bone defects caused by osteoporosis have always relied on bone tissue engineering. However, the preparation of composite tissue engineering scaffolds with a three-dimensional (3D) macroporous structure poses huge challenges in achieving osteoconduction and osteoinduction for repairing bone defects caused by osteoporosis. In the current study, a three-dimensional macroporous (150–300 μm) reduced graphene oxide/polypyrrole composite scaffold modified by strontium (Sr) (3D rGO/PPY/Sr) was successfully prepared using the oxygen plasma technology-assisted method, which is simple, safe, and inexpensive. The findings of the MTT assay and AO/EB fluorescence double staining showed that 3D rGO/PPY/Sr has a good biocompatibility and effectively promoted MC3T3-E1 cell proliferation. Furthermore, the ALP assay and alizarin red staining showed that 3D rGO/PPY/Sr increased the expression levels of ALP activity and the formation of calcified nodules. The desirable biocompatibility, osteoconduction, and osteoinduction abilities, assure that the 3D macroporous rGO/PPY/Sr composite scaffold offers promising potential for use in the repair of bone defects caused by osteoporosis in bone tissue engineering.     

Biocompatibility In-vitro of Gel/HA Composite Scaffolds Containing Nano-Bioactive Glass for Tissue Engineering

Designing and fabricating nanocomposite scaffolds for bone regeneration from different biodegradable polymers and bioactive materials are an essential step to engineer tissues. In this study, the composite scaffold of gelatin/hyaluronic acid (Gel/HA) containing nano-bioactive glass (NBG) was prepared by using freeze-drying method. The biocompatibilities in-vitro of the Gel-HA/NBG composite scaffolds, including MTT assay, ALP activity, von Kossa staining and tetracycline staining, were investigated. The SEM observations revealed that the prepared scaffolds were porous with three-dimensional (3D) and interconnected microstructure, agglomerated NBG particles were uniformly dispersed in the matrix. MTT results indicated that the tested materials didn't show any cytotoxicity. The presence of NBG in the composite scaffold further enhanced the ALP activity in comparison with the pure Gel/HA scaffold. The von Kossa staining and tetracycline staining results also indicated that the NBG may improve the cell response. Therefore, the results indicated the nanocomposite scaffold made from Gel, HA and NBG particles could be considered as a potential bone tissue engineering implant.     

3D Plotted PCL Scaffolds for Stem Cell Based Bone Tissue Engineering

The ability to control the architecture and strength of a bone tissue engineering scaffold is critical to achieve a harmony between the scaffold and the host tissue. Rapid prototyping (RP) technique is applied to tissue engineering to satisfy this need and to create a scaffold directly from the scanned and digitized image of the defect site. Design and construction of complex structures with different shapes and sizes, at micro and macro scale, with fully interconnected pore structure and appropriate mechanical properties are possible by using RP techniques. In this study, RP was used for the production of poly(ε-caprolactone) (PCL) scaffolds. Scaffolds with four different architectures were produced by using different configurations of the fibers (basic, basic-offset, crossed and crossed-offset) within the architecture of the scaffold. The structure of the prepared scaffolds were examined by scanning electron microscopy (SEM), porosity and its distribution were analyzed by micro-computed tomography (µ-CT), stiffness and modulus values were determined by dynamic mechanical analysis (DMA). It was observed that the scaffolds had very ordered structures with mean porosities about 60%, and having storage modulus values about 1 × 10⁷ Pa. These structures were then seeded with rat bone marrow origin mesenchymal stem cells (MSCs) in order to investigate the effect of scaffold structure on the cell behavior; the proliferation and differentiation of the cells on the scaffolds were studied. It was observed that cell proliferation was higher on offset scaffolds (262000 vs 235000 for basic, 287000 vs 222000 for crossed structure) and stainings for actin filaments of the cells reveal successful attachment and spreading at the surfaces of the fibers. Alkaline phosphatase (ALP) activity results were higher for the samples with lower cell proliferation, as expected. Highest MSC differentiation was observed for crossed scaffolds indicating the influence of scaffold structure on cellular activities.     

Incorporation of nanohydroxyapatite and vitamin D3 into electrospun PCL/Gelatin scaffolds: The influence on the physical and chemical properties and cell behavior for bone tissue engineering

Scaffold, an essential element of tissue engineering, should provide proper physical and chemical properties and evolve suitable cell behavior for tissue regeneration. Polycaprolactone/Gelatin (PCL/Gel)‐based nanocomposite scaffolds containing hydroxyapatite nanoparticles (nHA) and vitamin D3 (Vit D3) were fabricated using the electrospinning method. Structural and mechanical properties of the scaffold were determined by scanning electron microscopy (SEM) and tensile measurement. In this study, smooth and bead‐free morphology with a uniform fiber diameter and optimal porosity level with appropriate pore size was observed for PCL/Gel/nHA nanocomposite scaffold. The results indicated that adding nHA to PCL/Gel caused an increase of the mechanical properties of scaffold. In addition, chemical interactions between PCL, gelatin, and nHA molecules were shown with XRD and FT‐IR in the composite scaffolds. MG‐63 cell line has been cultured on the fabricated composite scaffolds; the results of viability and adhesion of cells on the scaffolds have been confirmed using MTT and SEM analysis methods. Here in this study, the culture of the osteoblast cells on the scaffolds showed that the addition of Vit D3 to PCL/Gel/nHA scaffold caused further attachment and proliferation of the cells. Moreover, DAPI staining results showed that the presence and viability of the cells were greater in PCL/Gel/nHA/Vit D3 scaffold than in PCL/Gel/nHA and PCL/Gel scaffolds. The results also approved increasing cell proliferation and alkaline phosphatase (ALP) activity for MG‐63 cells cultured on PCL/Gel/nHA/Vit D3 scaffold. The results indicated superior properties of hydroxyapatite nanoparticles and vitamin D3 incorporated in PCL/Gel scaffold for use in bone tissue engineering.     

Dual Therapy Coating on Micro/Nanoscale Porous Polyetheretherketone to Eradicate Biofilms and Accelerate Bone Tissue Repair

Defective osteogenesis and latent infections continue to be two major issues in the therapy of bone tissue regeneration. In this study, a unique hierarchically micro/nanoscale‐architecture is first proposed and produced on polyetheretherketone (PEEK). Besides, a “simvastatin‐PLLA film‐tobramycin microspheres” delivery system is subsequently fabricated to endow the PEEK implant with osteogenic and antibacterial capabilities. In vitro antibacterial evaluations confirm that the decorated PEEK scaffolds possess excellent resistance against planktonic/adherent bacteria. In vitro cell attachment/proliferation, lactate dehydrogenase (LDH) content, alkaline phosphatase (ALP) activity, calcium mineral deposition experiments, and real‐time PCR analysis all exhibit that the superior proliferation rate and osteo‐differentiation potential of MC3T3‐E1 pre‐osteoblasts are presented on the PEEK samples with dual functional decoration. In the mouse calvarial defect model, the micro‐CT and histological results demonstrate that our scaffolds display a remarkable bone forming capability. Generally, the PEEK scaffolds co‐endowed with simvastatin and tobramycin microspheres possess great potential in clinics.     

Preparation,Characterization, and In Vitro Biological Evaluation of PLGA/Nano-Fluorohydroxyapatite (FHA) Microsphere-Sintered Scaffolds for Biomedical Applications

In this research, the novel three-dimensional (3D) porous scaffolds made of poly(lactic-co-glycolic acid) (PLGA)/nano-fluorohydroxyapatite (FHA) composite microspheres was prepared and characterize for potential bone repair applications. We employed a microsphere sintering method to produce 3D PLGA/nano-FHA scaffolds composite microspheres. The mechanical properties, pore size, and porosity of the composite scaffolds were controlled by varying parameters, such as sintering temperature, sintering time, and PLGA/nano-FHA ratio. The experimental results showed that the PLGA/nano-FHA (4:1) scaffold sintered at 90 °C for 2 h demonstrated the highest mechanical properties and an appropriate pore structure for bone tissue engineering applications. Furthermore, MTT assay and alkaline phosphatase activity (ALP activity) results ascertained that a general trend of increasing in cell viability was seen for PLGA/nano-FHA (4:1) scaffold sintered at 90 °C for 2 h by time with compared to control group. Eventually, obtained experimental results demonstrated PLGA/nano-FHA microsphere-sintered scaffold deserve attention utilizing for bone tissue engineering.     

Effect of surface-modified collagen on the adhesion, biocompatibility and differentiation of bone marrow stromal cells in poly(lactide-co-glycolide)/chitosan scaffolds

The material-driven differentiation of bone marrow stromal cells (BMSCs) is a critical issue in regeneration medicine. In this study, we showed the differentiation of BMSCs in 3-D scaffolds consisting of collagen, poly(lactide-co-glycolide) (PLGA) and chitosan. The results revealed that the collagen-grafted PLGA/chitosan scaffolds yielded little cytotoxicity to BMSCs. The scaffold containing type I collagen of 640μg/mL was about 1.2 times the cell adhesion efficiency of the corresponding unmodified scaffold. In addition, the modification of type I collagen with the density of 640μg/mL increased about 1.3 times the cell viability and 1.2 times the biodegradation, respectively. The differentiation of BMSCs in PLGA/chitosan scaffolds produced osteoblasts with mineral deposition on the substrate. Moreover, the surface collagen promoted the formation of mineralized tissue and reduced the amount of phenotypic BMSCs in the constructs. However, the induction with neuron growth factor (NGF) inhibited osteogenesis and guided the differentiation of BMSCs towards neurons in the constructs. Therefore, the combination of collagen-functionalized PLGA/chitosan scaffolds, NGF and BMSCs can be promising in neural tissue engineering.     

Acceleration of osteogenic differentiation by sustained release of BMP2 in PLLA/graphene oxide nanofibrous scaffold

After about three decades of experience, tissue engineering has become one of the most important approaches in reconstructive medical research to treat non‐self‐healing bone injuries and lesions. Herein, nanofibrous composite scaffolds fabricated by electrospinning, which containing of poly(L‐lactic acid) (PLLA), graphene oxide (GO), and bone morphogenetic protein 2 (BMP2) for bone tissue engineering applications. After structural evaluations, adipose tissue derived mesenchymal stem cells (AT‐MSCs) were applied to monitor scaffold's biological behavior and osteoinductivity properties. All fabricated scaffolds had nanofibrous structure with interconnected pores, bead free, and well mechanical properties. But the best biological behavior including cell attachment, protein adsorption, and support cells proliferation was detected by PLLA‐GO‐BMP2 nanofibrous scaffold compared to the PLLA and PLLA‐GO. Moreover, detected ALP activity, calcium content and expression level of bone‐related gene markers in AT‐MSCs grown on PLLA‐GO‐BMP2 nanofibrous scaffold was also significantly promoted in compression with the cells grown on other scaffolds. In fact, the simultaneous presence of two factors, GO and BMP2, in the PLLA nanofibrous scaffold structure has a synergistic effect and therefore has a promising potential for tissue engineering applications in the repair of bone lesions.     

UPLC–Q‐TOF/MS characterization of efficacy substances on osteoblasts differentiation and function in rat serum after administration of Wang‐Bi tablet

Wang‐Bi tablet (WB) is popularly used for the treatment of rheumatoid arthritis. However, few studies have been carried out on its active ingredients and mechanism. In this study, the effect of WB medicated serum on the changes in differentiation and function in osteoblast was investigated, the results showed that WB induced the production of ALP and mineralized nodules to promote the final maturation of osteoblasts and enhance the function of osteoblasts. The potential mechanism may that WB significantly inhibits gene expressions of RANKL and miR‐141, up‐regulates the gene expressions of RUNX2 and OPG, decreases expression of DKK‐1 and increases levels of β‐catenin protein to promote the activation of Wnt/β‐catenin signaling pathways, which enhances osteogenesis and bone repair function. To investigate which compounds contributed to the activity and mechanisms, a total of 138 compounds were characterized from WB, and 13 parent molecules and eight metabolites in rat serum were rapidly characterized by UPLC–Q‐TOF/MS. Total glycosides of paeony, loganin, α‐linolenic acid, linoleic acid and naringin from WB may contribute to the actions on osteoblasts according to our study and literature review. Our research provides a method to explore the bioactive ingredients and action mechanisms of WB.     

DyCl_3对原代培养的成骨细胞增殖、分化和矿化功能表达的影响(英文)

采用MTT法、碱性磷酸酶活性测定、油红O的染色和定量测定、矿化功能的测定以及qRT-PCR等手段在细胞和分子水平上研究了DyCl3对原代培养的成骨细胞增殖、分化和矿化功能的影响。研究结果表明,在测试浓度范围内,DyCl3均抑制成骨细胞增殖。浓度为1×10-8,1×10-6和1×10-5mol·L-1的DyCl3促进成骨细胞分化。在测试浓度范围内,DyCl3均抑制成骨细胞横向分化为脂肪细胞。浓度为1×10-5mol·L-1的DyCl3促进成骨细胞矿化结节的形成,而浓度为1×10-7mol·L-1和1×10-6mol·L-1的DyCl3抑制成骨细胞矿化结节的形成,进一步降低浓度为1×10-8mol·L-1,它则对成骨细胞矿化功能没有影响。浓度1×10-6mol·L-1的DyCl3显著降低PPAR-γmRNA表达水平,但相同浓度DyCl3则显著上调RUNX-2mRNA表达水平。实验结果提示,DyCl3对体外培养的成骨细胞增殖、分化及矿化功能的影响与浓度和作用时间有关,而且,它们是影响其生物效应从毒性到活性,从损伤到保护,从上调到下调转变的关键因素。这些结果对深入理解稀土离子对骨代谢的影响具有重要的价值。     

与胶原特异性结合的BMP2模拟肽/PLGA 3D打印复合支架的制备及成骨诱导活性

将胶原绑定结构域(CBD)多肽序列与骨形态发生蛋白2模拟肽(BMP2-MP)序列连接制备具有胶原绑定能力的CBD-BMP2-MP, 再将CBD-BMP2-MP与聚丙交酯-乙交酯/胶原(PLGA/COL)3D打印支架相结合, 以支架表面的胶原成分为媒介, 将CBD-BMP2-MP更有效地固定于骨修复材料上, 达到对其进行改性的目的. 利用扫描电子显微镜(SEM)、 电子万能试验机和接触角测量仪对复合支架表面形貌、 力学强度和亲水性等材料学性能进行评价. 用荧光成像法评测 CBD-BMP2-MP及BMP2-MP与支架材料的结合能力. 在各组支架材料表面接种MC3T3-E1细胞进行体外培养, 采用CCK-8、 鬼笔环肽荧光染色、 茜素红染色及qPCR综合评价细胞在材料表面的黏附、 增殖和成骨分化等细胞行为, 研究CBD-BMP2-MP修饰的3D多孔PLGA/COL复合支架的生物学性能. 研究结果表明, 利用3D打印技术制备的多孔支架具有形貌可控的孔隙结构, 为细胞生长创造更有利的细胞微环境, 支架表面胶原成分的加入提高了支架材料的亲水性, 同时对支架材料本身的力学性能无任何影响, 提高了复合支架本身的生物相容性. 与普通BMP2-MP相比, CBD-BMP2-MP具有更好的胶原绑定能力, 与复合支架的结合更稳定, 提高了PLGA/COL复合支架对BMP2-MP的负载能力. 支架表面负载CBD-BMP2-MP后具有极强的促细胞成骨分化能力. MC3T3-E1细胞表现出更高的钙沉积能力, 并且成骨分化相关基因Runx2, ALP, COL-I及OPN等水平也有了明显提升. 表明CBD-BMP2-MP多孔复合支架具有良好的生物相容性和成骨诱导活性, 在骨组织修复领域具有良好的应用前景.     

Biocompatibility properties of composite scaffolds based on 1,4-butanediamine modified poly(lactide-co-glycolide) and nanobioceramics

Three-dimensional biodegradable porous scaffolds play an important role in tissue engineering. The degradable scaffold material, based on 1,4-butanediamine-modified poly(lactide-co-glycolide) (BMPLGA), nano-bioactive glass (NBAG), and nano-β-tricalciumphosphate (β-TCP), was prepared by a solution-casting/salt-leaching method. The biological properties were studied by using cell cytotoxicity, von Kossa staining, alkaline phosphatase activity, hemolytic test, acute toxicity, and genetic toxicity test. The MTT results indicated that the BMPLGA/NBAG-β-TCP materials did not show any cytotoxicity. The result of von Kossa staining showed that the introduction of the NBAG and β-TCP promoted fibroblastic differentiation and improved the mineral deposition of the BMPLGA matrix. In addition, the presence of NBAG and β-TCP in the composite further enhanced the ALP activity in comparison with the sole BMPLGA material. The hemolytic potential showed that the nanocomposite scaffolds were non-hemolytic. The BMPLGA/NBAG-β-TCP scaffolds showed no acute systemic toxicity or mutagenic action. Therefore, the results indicated the BMPLGA/NBAG-β-TCP nanocomposite scaffold could be considered as a potential bone tissue engineering implant.     

Improved efficacy of bio‐mineralization of human mesenchymal stem cells on modified PLLA nanofibers coated with bioactive materials via enhanced expression of integrin α2β1

Current therapeutic interventions in bone defects are mainly focused on finding the best bioactive materials for inducing bone regeneration via activating the related intracellular signaling pathways. Integrins are trans‐membrane receptors that facilitate cell‐extracellular matrix (ECM) interactions and activate signal transduction. To develop a suitable platform for supporting human bone marrow mesenchymal stem cells (hBM‐MSCs) differentiation into bone tissue, electrospun poly L‐lactide (PLLA) nanofiber scaffolds were coated with nano‐hydroxyapatite (PLLA/nHa group), gelatin nanoparticles (PLLA/Gel group), and nHa/Gel nanoparticles (PLLA/nHa/Gel group) and their impacts on cell proliferation, expression of osteoblastic biomarkers, and bone differentiation were examined and compared. MTT data showed that proliferation of hBM‐MSCs on PLLA/nHa/Gel scaffolds was significantly higher than other groups (P < .05). Alkaline phosphatase activity was also more increased in hBM‐MSCs cultured under osteogenic media on PLLA/nHa/Gel scaffolds compared to others. Gene expression evaluation confirmed up‐regulation of integrin α2β1 as well as the osteogenic genes BGLAP, COL1A1, and RUNX2. Following use of integrin α2β1 blocker antibody, the protein level of integrin α2β1 in cells seeded on PLLA/nHa/Gel scaffolds was decreased compared to control, which confirmed that most of the integrin receptors were bound to gelatin molecules on scaffolds and could activate the integrin α2β1/ERK axis. Collectively, PLLA/nHa/Gel scaffold is a suitable platform for hBM‐MSCs adhesion, proliferation, and osteogenic differentiation in less time via activating integrin α2β1/ERK axis, and thus it might be applicable in bone tissue engineering.     

Fabrication of poly(lactide‐co‐glycolide) scaffold embedded spatially with hydroxyapatite particles on pore walls for bone tissue engineering

Poly(lactide‐co‐glycolide) (PLGA) scaffolds embedded spatially with hydroxyapatite (HA) particles on the pore walls (PLGA/HA‐S) were fabricated by using HA‐coated paraffin spheres as porogens, which were prepared by Pickering emulsion. For comparisons, PLGA scaffolds loaded with same amount of HA particles (2%) in the matrix (PLGA/HA‐M) and pure PLGA scaffolds were prepared by using pure paraffin spheres as porogens. Although the three types of scaffolds had same pore size (450–600 µm) and similar porosity (90%–93%), the PLGA/HA‐S showed the highest compression modulus. The embedment of the HA particles on the pore walls endow the PLGA/HA‐S scaffold with a stronger ability of protein adsorption and mineralization as well as a larger mechanical strength against compression. In vitro culture of rat bone marrow stem cells revealed that cell morphology and proliferation ability were similar on all the scaffolds. However, the alkaline phosphatase activity was significantly improved for the cells cultured on the PLGA/HA‐S scaffolds. Therefore, the method for fabricating scaffolds with spatially embedded nanoparticles provides a new way to obtain the bioactive scaffolds for tissue engineering. Copyright © 2011 John Wiley & Sons, Ltd.     

Preparation of porous nanocomposite scaffolds with honeycomb monolith structure by one phase solution freezedrying method

Biodegradable porous nanocomposite scaffolds of poly（lactide-co-glycolide）（PLGA） and L-lactic acid（LAc） oligomer surface-grafted hydroxyapatite nanoparticles（op-HA） with a honeycomb monolith structure were fabricated with the single-phase solution freeze-drying method.The effects of different freezing temperatures on the properties of the scaffolds,such as microstructures,compressive strength,cell penetration and cell proliferation were studied.The highly porous and well interconnected scaffolds with a tunable pore structure were obtained.The effect of different freezing temperature（4℃,-20℃,-80℃and -196℃） was investigated in relation to the scaffold morphology,the porosity varied from 91.2%to 83.0%and the average pore diameter varied from（167.2±62.6）μm to（11.9±4.2）μm while theσ₁₀ increased significantly.The cell proliferation were decreased and associated with the above-mentioned properties.Uniform distribution of op-HA particles and homogeneous roughness of pore wall surfaces were found in the 4℃frozen scaffold.The 4℃frozen scaffold exhibited better cell penetration and increased cell proliferation because of its larger pore size,higher porosity and interconnection.The microstructures described here provide a new approach for the design and fabrication of op-HA/PLGA based scaffold materials with potentially broad applicability for replacement of bone defects.     

Poly(l‐Lactic Acid)/Gelatin Fibrous Scaffold Loaded with Simvastatin/Beta‐Cyclodextrin‐Modified Hydroxyapatite Inclusion Complex for Bone Tissue Regeneration

Recently, the application of nanostructured materials in the field of tissue engineering has garnered attention to mediate treatment and regeneration of bone defects. In this study, poly(l ‐lactic acid) (PLLA)/gelatin (PG) fibrous scaffolds are fabricated and β‐cyclodextrin (βCD) grafted nano‐hydroxyapatite (HAp) is coated onto the fibrous scaffold surface via an interaction between βCD and adamantane. Simvastatin (SIM), which is known to promote osteoblast viability and differentiation, is loaded into the remaining βCD. The specimen morphologies are characterized by scanning electron microscopy. The release profile of SIM from the drug loaded scaffold is also evaluated. In vitro proliferation and osteogenic differentiation of human adipose derived stem cells on SIM/HAp coated PG composite scaffolds is characterized by alkaline phosphatase (ALP) activity, mineralization (Alizarin Red S staining), and real time Polymerase chain reaction (PCR). The scaffolds are then implanted into rabbit calvarial defects and analyzed by microcomputed tomography for bone formation after four and eight weeks. These results demonstrate that SIM loaded PLLA/gelatin/HAp‐(βCD) scaffolds promote significantly higher ALP activity, mineralization, osteogenic gene expression, and bone regeneration than control scaffolds. This suggests the potential application of this material toward bone tissue engineering.

     

Effects of Laminin For Osteogenesis in Porous Hydroxyapatite

Summery: As a tooth is composed of hard tissue covering pulp, it may be suitable for tooth regeneration to use porous cylindrical hydroxyapatite (HA) scaffolds with a hollow center. Generally, in vivo examination, bone marrow cell suspension for osteogenesis in cell/HA composite scaffold without subculture is prepared at a density of 1 × 10⁷ cells/ml or higher. In dentistry, stem cells would be obtained from tooth pulp. For dentine formation, a smaller number of stem cells must be used. In this study, a suspension of rat bone marrow cells at 1 × 10⁶ cells/ml of density was prepared to estimate the adhesive effect of laminin. After immersion of HA scaffold in laminin solution, bone marrow cells were seeded in the pores of the HA scaffolds by immersion in the cell suspension for preparing the cell/HA composite scaffolds. The specimens were respectively implanted in the dorsal subcutis of 7-week-old male Fischer 344 rats for 4 weeks for histological examination. Comparing with the results of in vivo examination, alkaline phosphatase activity of bone marrow cells on laminin-coated plate with and without dexamethasone cultured for 2 weeks was measured in vitro. It was considered that laminin contributed to bone formation in pores of a scaffold.     

Cellulose nanocrystals as biobased nucleation agents in poly-l-lactide scaffold: Crystallization behavior and mechanical properties

The mechanical strength of polymer scaffold is closely related to its crystallinity. In this work, cellulose nanocrystals (CNC) were incorporated into poly-l-lactide (PLLA) scaffold which was fabricated by selective laser sintering, aiming to improve the mechanical properties. CNC possesses numerous hydroxyl groups which might form hydrogen bond with PLLA molecular chains. The hydrogen bond induces the ordered arrangement of PLLA chain by using CNC as heterogeneous nucleating agent, thereby increasing crystallization rate and crystallinity. Results showed that PLLA scaffolds with 3 wt% CNC resulted in 191%, 351%, 34%, 83.5%, 56% increase in compressive strength, compressive modulus, tensile strength, tensile modulus and Vickers hardness, respectively. Encouragingly, with the incorporation of hydrophilic CNC, the PLLA/CNC scaffolds showed not only better hydrophilicity, but also faster degradation than PLLA. In vitro cell culture studies proved that the PLLA/CNC scaffolds were biocompatible and capable of supporting cell adhesion, proliferation and differentiation. The above results indicated that the PLLA/CNC scaffolds may therefore be a potential replacement in bone repair.     

Synergistic Effects of Beta Tri‐Calcium Phosphate and Porcine‐Derived Decellularized Bone Extracellular Matrix in 3D‐Printed Polycaprolactone Scaffold on Bone Regeneration

Bone‐derived extracellular matrix (ECM) is widely used in studies on bone regeneration because of its ability to provide a microenvironment of native bone tissue. However, a hydrogel, which is a main type of ECM application, is limited to use for bone graft substitutes due to relative lack of mechanical properties. The present study aims to fabricate a scaffold for guiding effective bone regeneration. A polycaprolactone (PCL)/beta‐tricalcium phosphate (β‐TCP)/bone decellularized extracellular matrix (dECM) scaffold capable of providing physical and physiological environment are fabricated using 3D printing technology and decoration method. PCL/β‐TCP/bone dECM scaffolds exhibit excellent cell seeding efficiency, proliferation, and early and late osteogenic differentiation capacity in vitro. In addition, outstanding results of bone regeneration are observed in PCL/β‐TCP/bone dECM scaffold group in the rabbit calvarial defect model in vivo. These results indicate that PCL/β‐TCP/bone dECM scaffolds have an outstanding potential as bone graft substitutes for effective bone regeneration.