A 3D Bioprinted Nanoengineered Hydrogel with Photoactivated Drug Delivery for Tumor Apoptosis and Simultaneous Bone Regeneration via Macrophage Immunomodulation

One of the significant challenges in bone tissue engineering (BTE) is the healing of traumatic tissue defects owing to the recruitment of local infection and delayed angiogenesis. Herein, a 3D printable multi-functional hydrogel composing polyphenolic carbon quantum dots (CQDs, 100 µg mL⁻¹) and gelatin methacryloyl (GelMA, 12 wt%) is reported for robust angiogenesis, bone regeneration and anti-tumor therapy. The CQDs are synthesized from a plant-inspired bioactive molecule, 1, 3, 5-trihydroxybenzene. The 3D printed GelMA-CQDs hydrogels display typical shear-thinning behavior with excellent printability. The fabricated hydrogel displayed M2 polarization of macrophage (Raw 264.7) cells via enhancing anti-inflammatory genes (e.g., IL-4 and IL10), and induced angiogenesis and osteogenesis of human bone mesenchymal stem cells (hBMSCs). The bioprinted hBMSCs are able to produce vessel-like structures after 14 d of incubation. Furthermore, the 3D printed hydrogel scaffolds also show remarkable near infra-red (NIR) responsive properties under 808 nm NIR light (1.0 W cm⁻²) irradiation with controlled release of antitumor drugs (≈49%) at pH 6.5, and thereby killing the osteosarcoma cells. Therefore, it is anticipated that the tissue regeneration and healing ability with therapeutic potential of the GelMA-CQDs scaffolds may provide a promising alternative for traumatic tissue regeneration via augmenting angiogenesis and accelerated immunomodulation.     

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.     

Poly(l,l-lactide-co-glycolide)/tricalcium phosphate composite scaffold and its various changes during degradation in vitro

A poly(l,l-lactide-co-glycolide) (70/30)/(tricalcium phosphate) (PLGA/TCP) composite scaffold was fabricated by low-temperature deposition (LDM) and its degradation performed in vitro for 22 weeks. Various changes during degradation in vitro, which included changes in acidity of the degradation medium, morphology, weight, composition, molecular weight of the PLGA component and mechanical properties of the scaffold, were investigated. It was found that the acidity of degradation medium of the PLGA(70/30)/TCP composite scaffolds reduced and became much lower than that of TCP-free scaffold. With degradation, the volume and porosity of the PLGA(70/30)/TCP composite scaffold reduced at first then increased slowly, while the surface morphology of the scaffold changed from smooth to rough. The weight loss of the scaffold increased by dissolution of the degraded products and TCP component, but mainly by dissolution of the glycyl-rich degraded products of the PLGA component. The molecular weight of the PLGA component reduced with time, but the molecular weight distribution increased at first and then reduced. The compressive strength and modulus of the scaffold increased at first and then reduced with further degradation. The effect of degradation on modulus was much bigger than that on compressive strength. Based on excellent cell affinity of the PLGA(70/30)/TCP composite scaffold, a potentially useful bone tissue engineering scaffold is proposed.     

Controlled release of doxorubicin from electrospun MWCNTs/PLGA hybrid nanofibers

In this study, multiwalled carbon nanotubes (MWCNTs) were used to encapsulate a model anticancer drug, doxorubicin (Dox). Then, the drug-loaded MWCNTs (Dox/MWCNTs) with an optimized drug encapsulation percentage were mixed with poly(lactide-co-glycolide) (PLGA) polymer solution for subsequent electrospinning to form drug-loaded composite nanofibrous mats. The structure, morphology, and mechanical properties of the formed electrospun Dox/PLGA, MWCNTs/PLGA, and Dox/MWCNTs/PLGA composite nanofibrous mats were characterized using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy, and tensile testing. In vitro viability assay and SEM morphology observation of mouse fibroblast cells cultured onto the MWCNTs/PLGA fibrous scaffolds demonstrate that the developed MWCNTs/PLGA composite nanofibers are cytocompatible. The incorporation of Dox-loaded MWCNTs within the PLGA nanofibers is able to improve the mechanical durability and maintain the three-dimensional structure of the nanofibrous mats. More importantly, our results indicate that this double-container drug delivery system (both PLGA polymer and MWCNTs are drug carriers) is beneficial to avoid the burst release of the drug and able to release the antitumor drug Dox in a sustained manner for 42 days. The developed composite electrospun nanofibrous drug delivery system may be used as therapeutic scaffold materials for post-operative local chemotherapy.     

In Vivo Degradation Behavior of Porous Composite Scaffolds of Poly（lactide-co-glycolide） and Nano-hydroxyapatite Surface Grafted with Poly（L-lactide）

The biodegradable porous composite scaffold, composed of poly(lactide-co-glycolide)(PLGA) and hydroxyapatite nanoparticles(n-HAP) surface-grafted with poly(L-lactide)(PLLA)(g-HAP)(g-HAP/PLGA), was fabricated using the solvent casting/particulate leaching method, and its in vivo degradation behavior was investigated by the intramuscular implantation in rabbits. The composite of un-grafted n-HAP/PLGA and neat PLGA were used as controls. The scaffolds had interconnected pore structures with average pore sizes between 137 μm and 148 μm and porosities between 83% and 86%. There was no significant difference in the pore size and porosity among the three scaffolds. Compared with n-HAP/PLGA, the thermo-degradation temperature(Tc) of g-HAP/PLGA decreased while its glass transition temperature(Tg) increased. The weight change, grey value analysis of radiographs and SEM observation showed that the composite scaffolds of g-HAP/PLGA and n-HAP/PLGA showed slower degradation and higher mineralization than the pure PLGA scaffold after the intramuscular implantation. The rapid degradation of PLGA, g-HAP/PLGA and n-HAP/PLGA occurred at 8–12 weeks, 12–16 weeks and 16–20 weeks, respectively. Compared with n-HAP/PLGA, g-HAP/PLGA showed an improved absorption and biomineralization property mostly because of its improved distribution of HAP nanoparticles. The levels of both calcium and phosphorous in serum and urine could be affected to some extent at 3–4 weeks after the implantation of g-HAP/PLGA, but the biochemical detection of serum AST, ALT, ALP, and GGT as well as BUN and CRE showed no obvious influence on the functions of liver and kidney.     

Biomimetic hybrid scaffold containing niosomal deferoxamine promotes angiogenesis in full-thickness wounds

Effective management of full-thickness wounds faces significant challenges due to poor angiogenesis and impaired healing. Biomimetic tissue-engineered scaffolds with angiogenic properties can, however, enhance the regeneration capacity of the damaged skin. Here, we developed a hybrid double-layer nanofibrous scaffold, comprised of egg white (EW) and polyvinyl alcohol (PVA), loaded with niosomal Deferoxamine (NDFO) for enhanced angiogenesis and wound healing features. The hybrid scaffold showed enhanced mechanical properties with comparable modulus and shape-recovery behavior of the human skin. Thanks to the porous morphology and uniform distribution of NDFO within the nanofibers, in vitro drug release studies indicated controlled and sustained release of DFO for up to 9 days. The constructs also promoted a significant increase in vascular sprouting area in vitro and enhanced vascular branches ex vivo. In vivo, implantation of the hybrid scaffold in full-thickness wounds in rats revealed early angiogenic response, a higher number of neo-formed vessels, a faster healing rate and complete epithelialization as early as day 10, compared to the control groups. Thus, the presented biomimetic hybrid scaffold with DFO control release features holds great promise in accelerated full-thickness wound healing and soft tissue regeneration.     

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.     

Bioactive gelatin cryogels with BMP-2 biomimetic peptide and VEGF:A potential scaffold for synergistically induced osteogenesis

A poor biocompatibility and bioactivity of invasive materials remains major problems for biomaterialbased therapy. In this study, we introduced gelatin scaffolds carrying both bone morphogenetic protein-2(BMP-2) biomimetic peptide and vascular endothelial growth factor-165(VEGF) that achieved controlled release, cell attachment, proliferation and differentiation. To promote osteogenesis with VEGF, we designed the BMP-2 biomimetic peptide that comprised BMP-2 core sequence oligopeptide(SSVPT), ph...     

Cell‐Free HA‐MA/PLGA Scaffolds with Radially Oriented Pores for In Situ Inductive Regeneration of Full Thickness Cartilage Defects

A bioactive scaffold with desired microstructure is of great importance to induce infiltration of somatic and stem cells, and thereby to achieve the in situ inductive tissue regeneration. In this study, a scaffold with oriented pores in the radial direction is prepared by using methacrylated hyaluronic acid (HA‐MA) via controlled directional cooling of a HA‐MA solution, and followed with photo‐crosslinking to stabilize the structure. Poly(lactide‐co‐glycolide) (PLGA) is further infiltrated to enhance the mechanical strength, resulting in a compressive modulus of 120 kPa. In vitro culture of bone marrow stem cells (BMSCs) reveals spontaneous cell aggregation inside this type of scaffold with a spherical morphology. In vivo transplantation of the cell‐free scaffold in rabbit knees for 12 w regenerates simultaneously both cartilage and subchondral bone with a Wakitani score of 2.8. Moreover, the expression of inflammatory factor interleukin‐1β (IL‐1β) is down regulated, although tumor necrosis factor‐α (TNF‐α) is remarkably up regulated. With the anti‐inflammatory, bioactive properties and good restoration of full thickness cartilage defect in vivo, the oriented macroporous HA‐MA/PLGA hybrid scaffold has a great potential for the practical application in the in situ cartilage regeneration.

     

Tantalum nanoparticles enhance the osteoinductivity of multiscale composites based on poly(lactide-co-glycolide) electrospun fibers embedded in a gelatin hydrogel

Bioresorbable polymeric materials have risen great interest as implants for bone tissue regeneration, since they show substantial advantages with respect to conventional metal devices, including biodegradability, flexibility, and the possibility to be easily modified to introduce specific functionalities. In the present work, an innovative nanocomposite scaffold, properly designed to show biomimetic and osteoinductive properties for potential application in bone tissue engineering, was developed. The scaffold is characterized by a multi-layer structure, completely different with respect to the so far employed polymeric implants, consisting in a poly(d,l-lactide-co-glycolide)/polyethylene glycol electrospun nanofibrous mat sandwiched between two hydrogel gelatin layers enriched with tantalum nanoparticles (NPs). The composition of the electrospun fibers, containing 10 wt% of polyethylene glycol, was selected to ensure a proper integration of the fibers in the gel phase, essential to endow the composite with flexibility and to prevent delamination between the layers. The scaffold maintained its structural integrity after six weeks of soaking in physiological solutions, albeit the gelatin phase was partially released. The combined use of gelatin, bioresorbable electrospun fibers and tantalum NPs endows the final device with biomimetic and osteoinductive properties. Indeed, results of the in vitro tests demonstrate that the obtained scaffolds clearly represent a favorable milieu for normal human bone-marrow derived mesenchymal stem cells viability and osteoblastic differentiation; moreover, inclusion of tantalum NPs in the scaffold improves cell performance with particular regard to early and late markers of osteoblastic differentiation.     

Mesoporous porphyrinic metal-organic framework nanoparticles/3D nanofibrous scaffold as a versatile platform for bone tumor therapy

Removal of residual tumor cells and regeneration of large bone defects are urgently required after surgical resection of bone tumors. To address these issues, a bifunctional scaffold with high photothermal effect and osteogenesis was developed for bone tumor therapy. Sintered mesoporous imidazolate framework 8 (ZIF8) nanoparticles with porphyrin-like macrocycles were synthesized by calcination of ZIF8 precursors under an N₂ atmosphere. The prepared ZIF8 possesses good photothermal efficacy and drug loading capability. Phenamil (Phe), an activator of bone morphogenetic protein pathways, was encapsulated into ZIF8 before loading onto gelatin nanofibrous (GF) scaffolds. The loaded Phe exhibited sustained and near-infrared triggered release profiles, which is capable of promoting bone morphogenetic protein 2 induced osteogenic differentiation even under near-infrared treatment. Moreover, our studies revealed that the photothermal effect of GF/ZIF8-Phe scaffolds can kill MG-63 cells in vitro and inhibit subcutaneous tumor growth in vivo. Therefore, the GF/ZIF8-Phe scaffold represents a novel bifunctional platform for tumor therapy and bone regeneration.     

A collagen(Col)/nano-hydroxyapatite (nHA) biological composite bone scaffold with double multi-level interface reinforcement

IntroductionBone scaffold is expected to possess excellent mechanical and biological properties similar to natural bone tissues. In this study, we aimed to prepare a biomineralized Col and hydroxyapatite composite scaffold consisting of biomimetic bone components and multi-level bionic bone structure to strengthen its mechanical properties.MethodsWe prepared a Col/nano-hydroxyapatite biological composite scaffold with multi-level structure (from nanofibers to micron bionic bone motif to bionc bone scaffold) of biomimetic bone tissue, and biomineralized the scaffold in simulated body fluid (SBF) preheated to 37 °C. X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy and Scanning electron microscope, were used to characterize the biomineralized products.ResultsMorphological study confirmed in situ deposition of nHA in the multi-scale hierarchical structure of the biomineralized scaffold. We explored the biomineralization nucleation mechanism of the scaffolds at the atomic level based on the first principles and the mechanisms for growth of mineralized nHA crystal array in its multi-scale structure, and how the double multiscales structure strengthened the mechanical properties of the material.ConclusionsThis synthetic bone scaffold, with bionic bone composition and double multi-level interface reinforcement, provides a new strategy for synthesizing bioactive bone scaffolds with enhanced biomechanical properties.     

In vitro degradation of porous poly(dl-lactide-co-glycolide) (PLGA)/bioactive glass composite foams with a polar structure

In vitro degradation of porous 50/50, 70/30 and 90/10 PLGA (poly(dl-lactide-co-glycolide)) foams and PLGA/bioactive glass (20 wt%) composite foams was studied up to 16 weeks in TRIS (pH 7.4; 37 °C). Polar PLGA/bioactive glass composite films were prepared by applying the bioactive glass (S53P4) on one side of the composite. Porous foams were made by solvent casting and pressure quenching with CO₂. The fabricated foams had an initial pore size of 50-500 μm and thickness of 2-2.5 mm. In vitro degradation of the prepared foams was evaluated after 1, 2, 4, 6, 8, 12 and 16 weeks. Weight loss, water uptake, molecular mass and the amount of dissolved bioactive glass were measured after each time period. Changes in pore morphology were analysed with SEM. The present in vitro results will be evaluated and compared with the results from ongoing animal studies where comparable implants are used for bone defect treatment under non-load-bearing conditions.     

Enhanced mechanical performance and biological evaluation of a PLGA coated β-TCP composite scaffold for load-bearing applications

Porous β-tricalcium phosphate (β-TCP) has been used for bone repair and replacement in clinics due to its excellent biocompatibility, osteoconductivity, and biodegradability. However, the application of β-TCP has been limited by its brittleness. Here, we demonstrated that an interconnected porous β-TCP scaffold infiltrated with a thin layer of poly(lactic-co-glycolic acid) (PLGA) polymer showed improved mechanical performance compared to an uncoated β-TCP scaffold while retaining its excellent interconnectivity and biocompatibility. The infiltration of PLGA significantly increased the compressive strength of β-TCP scaffolds from 2.90 to 4.19 MPa, bending strength from 1.46 to 2.41 MPa, and toughness from 0.17 to 1.44 MPa, while retaining an interconnected porous structure with a porosity of 80.65%. These remarkable improvements in the mechanical properties of PLGA-coated β-TCP scaffolds are due to the combination of the systematic coating of struts, interpenetrating structural characteristics, and crack bridging. The in vitro biological evaluation demonstrated that rat bone marrow stromal cells (rBMSCs) adhered well, proliferated, and expressed alkaline phosphatase (ALP) activity on both the PLGA-coated β-TCP and the β-TCP. These results suggest a new strategy for fabricating interconnected macroporous scaffolds with significantly enhanced mechanical strength for potential load-bearing bone tissue regeneration.     

A quaternary composite fiber membrane for guided tissue regeneration

This work reported a novel composite fiber membrane containing poly(1actic‐co‐glycolic acid)/six‐armed poly(ε‐caprolactone)/hydroxylapatite‐grafted poly(l ‐lactide)/Pluronic F‐108 (PLGA/SAPCL/HA‐g‐PLLA/PF‐108) produced by electrospinning. SAPCL, HA‐g‐PLLA, and PF‐108 could be well blended with PLGA to make fibers. Fibrous surface and diameter had little difference in morphology with the change of fibrous component. Compared with simple PLGA, PLGA/SAPCL, or PLGA/SAPCL/HA‐g‐PLLA fiber membrane, the quaternary composites not only showed the improved mechanics stability but also possessed better hydrophilicity. The quaternary membrane was conductive to accelerate degradation and maintained nice bioactivity. It was not cytotoxicity. These results suggest that the composite fiber membrane may be qualified as guided bone regeneration substrate. Copyright © 2015 John Wiley & Sons, Ltd.     

The dose-effect of icariin on the proliferation and osteogenic differentiation of human bone mesenchymal stem cells

Icariin had been reported as a potential agent for osteogenesis, but the dose-effect relationship needed further research to realize the clinical application of icariin. We isolated and purified human bone mesenchymal stem cells (hBMSCs) and stimulated them with different concentrations of icariin. The cytotoxicity of icariin was evaluated by the methylthiazolytetrazolium (MTT) assay method. The proliferation and osteogenic differentiation of such hBMSCs were investigated for different concentrations of icariin. We found that icariin had a dose-dependent effect on the proliferation and osteogenic differentiation of hBMSCs in a suitable concentration range from 10(-9) M to 10(-6) M, but at concentrations above 10(-5) M, the cytotoxicity limited its use. The extremely low cost of icariin and its high abundance make it appealing for bone regeneration.     

Development of nano-tricalcium phosphate/polycaprolactone/platelet-rich plasma biocomposite for bone defect regeneration

Nano-tricalcium phosphate (n-TCP) is an osteoconductive substance which, like polycaprolactone (PCL), has been used for clinical purposes for many years; It has now been licensed for a range of products for clinical and medication distribution. This research aimed to examine the effects of platelet-rich plasma on mesenchymal stem cell proliferation and osteogenic differentiation. Thus, we decided to examine the in vitro and in vivo actions of PRP-treated porous biocomposite scaffolds based on nano-tricalcium phosphate- polycaprolactone (n-TCP-PCL/PRP). The prepared samples were described utilizing FTIR, XRD, and SEM. MTT has measured the cytotoxicity of the biocomposite scaffolds. After two weeks of cell seeding, Alizarin red staining confirmed bone mineral formation by MSCs cells. Moreover, from day 4 to day 7, n-TCP-PCL/PRP biocomposite scaffold improved the expresses of bone marker genes. Platelet-rich plasma (PRP) in conjunction with nano-tricalcium phosphate- polycaprolactone (n-TCP-PCL) biocomposite scaffold is beneficial for the regeneration and stability of the freshly developed bone tissue.     

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.     

A Silk Fibroin and Peptide Amphiphile‐Based Co‐Culture Model for Osteochondral Tissue Engineering

New biomaterials with the properties of both bone and cartilage extracellular matrices (ECM) should be designed and used with co‐culture systems to address clinically applicable osteochondral constructs. Herein, a co‐culture model is described based on a trilayered silk fibroin‐peptide amphiphile (PA) scaffold cultured with human articular chondrocytes (hACs) and human bone marrow mesenchymal stem cells (hBMSCs) in an osteochondral cocktail medium for the cartilage and bone sides, respectively. The presence of hACs in the co‐cultures significantly increases the osteogenic differentiation potential of hBMSCs based on ALP activity, RT‐PCR for osteogenic markers, calcium analyses, and histological stainings, whereas hACs produces a significant amount of glycosaminoglycans (GAGs) for the cartilage region, even in the absence of growth factor TGF‐β family in the co‐culture medium. This trilayered scaffold with trophic effects offers a promising strategy for the study of osteochondral defects.

     

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.