Materials For Bone Tissue Engineering Research Articles

Silk Fibroin Magnetoactive Nanocomposite Films and Membranes for Dynamic Bone Tissue Engineering Strategies

Bone-related diseases are one of the most common health conditions that limit the quality of life of elderly. Novel materials for bone tissue engineering that actively assist on the regeneration of bone tissue are thus needed. In this work, magnetoactive scaffolds comprised of silk fibroin (SF) with different content of filler- cobalt ferrite nanoparticles- were produced by solvent-casting and electrospinning technique and further evaluated for bone cells growth under static and dynamic magnetic stimulation. The materials were evaluated for their enhanced electric properties, analyzed through the silk fibroin β-sheet content, an important factor for the envisaged cell stimulation strategy, which are in much higher content in films (~50%) than in electrospun fibres (~25%). Cell culture experiments under varying magnetic field, induced a magneto-mechanical stimulation on the materials, hence on cells, promoting improved cell viability after 4 days of culture. The scaffold morphology was found to play an important role in pre-osteoblast proliferation rate, being larger for cells growing on films, which is related to the topography of the material but also to the increased β-sheet content. It is shown that the use of magnetic cues on magnetoactive biocompatible scaffolds is a promising strategy for remote stimulation of bone for its regeneration.

Arabinoxylan-co-AA/HAp/TiO2 nanocomposite scaffold a potential material for bone tissue engineering: An in vitro study

Arabinoxylan (AX) is a natural biological macromolecule with several potential biomedical applications. In this research, AX, nano-hydroxyapatite (n-HAp) and titanium dioxide (TiO2) based polymeric nanocomposite scaffolds were fabricated by the freeze-drying method. The physicochemical characterizations of these polymeric nanocomposite scaffolds were performed for surface morphology, porosity, swelling, biodegradability, mechanical, and biological properties. The scaffolds exhibited good porosity and rough surface morphology, which were efficiently controlled by TiO2 concentrations. MC3T3-E1 cells were employed to conduct the biocompatibility of these scaffolds. Scaffolds showed unique biocompatibility in vitro and was favorable for cell attachment and growth. PNS3 proved more biocompatible, showed interconnected porosity and substantial mechanical strength compared to PNS1, PNS2 and PNS4. Furthermore, it has also showed more affinity to cells and cell growth. The results illustrated that the bioactive nanocomposite scaffold has the potential to find applications in the tissue engineering field.

β-tricalcium phosphate and octacalcium phosphate composite bioceramic material for bone tissue engineering.

In bone tissue engineering, suitable mechanical properties and excellent biological performance of biological substitutes are required. β-tricalcium phosphate has superior biocompatibility compared...

Fabrication and Application of a 3D-Printed Poly-ε-Caprolactone Cage Scaffold for Bone Tissue Engineering.

Poly-ε-caprolactone (PCL) is a promising synthetic material in bone tissue engineering (BTE). Particularly, the introduction of rapid prototyping (RP) represents the possibility of manufacturing PCL scaffolds with customized appearances and structures. Bio-Oss is a natural bone mineral matrix with significant osteogenic effects; however, it has limitations in being constructed and maintained into specific shapes and sites. In this study, we used RP and fabricated a hollow-structured cage-shaped PCL scaffold loaded with Bio-Oss to form a hybrid scaffold for BTE. Moreover, we adopted NaOH surface treatment to improve PCL hydrophilicity and enhance cell adhesion. The results showed that the NaOH-treated hybrid scaffold could enhance the osteogenesis of human bone marrow-derived mesenchymal stem cells (hBMMSCs) both in vitro and in vivo. Altogether, we reveal a novel hybrid scaffold that not only possesses osteoinductive function to promote bone formation but can also be fabricated into specific forms. This scaffold design may have great application potential in bone tissue engineering.

Preparation and properties of a highly dispersed nano-hydroxyapatite colloid used as a reinforcing filler for chitosan.

Hydroxyapatite/chitosan (HAp/CS) composites have been widely studied and applied in tissue engineering fields due to their excellent biocompatibility and degradability. However, to improve the mechanical properties of CS, cross-linking agents are commonly added, which will seriously affect its biocompatibility and safety. In this study, the homogenously dispersed nano-hydroxyapatite (nHAp) colloidal solution was first synthesized using a co-precipitation method. The three-dimensional porous nano-hydroxyapatite/chitosan (nHAp/CS) composite scaffolds with different nHAp contents were then obtained through an environmentally friendly freeze-drying process without any cross-linking. The microstructure, porosity, phase composition, swelling ratio, mechanical properties, and biocompatibility of the nHAp/CS scaffolds were thoroughly investigated. The as-prepared nHAp/CS scaffolds exhibited a high porosity and excellent swelling performance. Compared with pure CS scaffolds, the nHAp/CS composite scaffolds not only showed higher compressive modulus but also exhibited better biocompatibility. This study provides a simple and environmentally friendly technique to construct three-dimensional porous nHAp/CS composite scaffolds, which demonstrate promising potential by being a scaffold material for bone tissue engineering.

In vitro and in vivo biocompatibility and bio-tribological properties of the calcium/amorphous-C composite films for bone tissue engineering application

Carbon-and diamond-like-carbon coated Ti alloys hold great promise for tissue engineering applications. Unfortunately, their strong intrinsic stress leads to the adhesion failure of the films. Herein, a series of a-C films with different Ca content were prepared on Ti6Al4V via co-sputtering deposition technology. Homogeneous spherical Ca nanoclusters, with an inner diameter of 2−6 nm, were formed in an amorphous carbon matrix. The addition of Ca induced indistinctive variation in either phase composition or topography. However, the introduction of Ca not only improved the mechanical properties of a-C film but also significantly strengthened its adhesion to osteoblasts. The bio-tribological properties of Ca/a-C films were also assessed using a tribometer in FBS solution. The Ca/a-C films exhibited a low friction coefficient of 0.083 and a low wear rate of 1.02-1.24×10−6 mm3/Nm. The low coefficient of friction (COF) of the Ca/a-C films indicates their superior mechanical properties, making them the promising target of nanocomposite films used in bio-tribological applications. Well-stretched cells and the developed actin filaments were distinctly observed on the Ca/a-C films in the osteoblast cell adhesion experiments. In addition, the Ca/a-C films promoted cell proliferation and showed high cell viability. After being implanted for 4 weeks, the Ca/a-C implant material still adhered well to the muscle tissue, without inducing hyperergic or inflammatory reactions. Collectively, our results suggest that the Ca/a-C film is an ideal mounting material for bone tissue engineering.

Cross-linked gelatin-nanocellulose scaffolds for bone tissue engineering

Wood-based cellulose nanofibrils (CNFs) have, in addition to high specific surface area and high surface reactivity, ability to mimic nanostructured collagen in bone extracellular matrix. These properties make CNFs promising materials for bone tissue engineering (BTE). The CNFs degrade slowly in vivo. By blending and cross-linking gelatin (Gel) with CNFs, scaffolds were produced with tuned degradation rate and enhanced mechanical properties, more suitable for BTE applications. This in vitro study aimed to examine initial biological responses of human bone marrow mesenchymal stem cells to cross-linked Gel-CNF scaffolds. The scaffolds were fabricated from 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-oxidized CNF blended with Gel and cross-linked either by dehydrothermal treatment (DHT) or by a combination of hexamethylenediamine, genipin, and DHT. CNF scaffolds without cross-linking served as control. The produced scaffolds supported cell attachment, spreading, and osteogenic differentiation. However, the early cell attachment after 1 day and the expression of RUNX2 and SPP1 genes after 7 days were highest in the CNF scaffolds. The results suggest that cross-linked Gel-CNF are cytocompatible and holds potential for BTE applications.

Bioactive Materials for Bone Tissue Engineering

Bioactive Materials for Bone Tissue Engineering

Preparation and Characterization of α-Calcium Sulfate Hemihydrate (CSH)/Marine Shells Scaffold with Cervus and Cucumis Polypeptide Composite Biomaterials for Bone Reconstruction

Objective: Calcium sulfate, calcium carbonate and Cervus and Cucumis Polypeptide have been widely used for bone reconstruction. However, each of them has limitations. We aim to prepare and evaluate the safety and biocompatibility of α-calcium sulfate hemihydrate (CSH)/marine shells scaf- fold with cervus and cucumis polypeptide composites. Methods: α-CSH/marine shell scaffold with cervus and cucumis polypeptide composite was first prepared by chemical coprecipitation and the hydrothermal method. The cell morphology and proliferation in L929 fibroblasts and bone marrow stromal cells were tested by MTT assay. Phase composition and microstructure of the composites was determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM). In vivo Tox- icity tests indicated that composites are biocompatible and can be used as a safe bone implant in SD rats. Results: The structure, morphology and properties of α-calcium sulfate hemihydrate (CSH)/marine shells scaffold with cervus and cucumis polypeptide composites are characterized. The compressive strength of the composite was more than 6MPa which is adequate for clinical needs. The morphology of L929 fibroblasts and bone marrow stromal cells remain normal and could proliferate rapidly. Remarkably, the composites showed good biocompatibility in vivo since no toxicity and irritation effects were observed in rat muscles. Conclusion: Our study first prepared α-CSH/marine shell scaffold with cervus and cucumis polypeptide composites and proved its good biocompatibility, which is a desirable and suitable material for bone tissue engineering.

Высоконаполненные композиции на основе альгинатного геля и мелкодисперсного трикальцийфосфата для трёхмерной печати тканеинженерных матриксов

In order to obtain hydrogel matrices for bone tissue engineering, the process of formation of highly filled alginate-calcium phosphate structures by 3D printing was developed. Optimal conditions for the formation of three-dimensional structures from Ca2+ crosslinked alginate hydrogels and highly filled alginate compositions with fine (5–30 μm) α-tricalcium phosphate (TCP) were determined. Comparative analysis of physicomechanical properties of crosslinked alginate hydrogels showed lower strength and higher elastic modulus of the TCP-filled composite in comparison with pure hydrogel. The difference between the mechanical characteristics of the filled and pure gels increases with the crosslinking density. It was found that, because of the significant content of the mineral dispersed phase, the α-TCP-filled hydrogel does not shrink during crosslinking, unlike pure alginate hydrogel. Using cultures of human umbilical cord mesenchymal stem cells, it was shown in vitro that all the studied samples of both pure and highly filled composite alginate matrices with α-TCP do not have short-term cytotoxic effects.

Enhancing Osteochondral Tissue Regeneration of Gellan Gum by Incorporating Gallus gallus var Domesticus-Derived Demineralized Bone Particle.

Treatment for the osteochondral defects (ODs) is more challenging nowadays that needs to be addressed by developing alternative bone tissue engineering materials. Gellan gum (GG) is a widely used natural polysaccharide in the field of tissue engineering (TE) and regenerative medicine due to its versatile properties. There are many reports about the successful application of GG in cartilage tissue engineering and guiding bone formation. Functional coatings and porous composite materials have been introduced in next-generation materials for treating OD, whereas osteoconductive materials, such as demineralized bone particle (DBP) or bone derivatives, are used. However, modification of porosity, biocompatibility, cell proliferation, and mechanical properties is needed. DBP can activate human mesenchymal stem cells to differentiate into osteoblast cells. In this chapter, the potential application of GG with DBP in different combinations was reviewed, and the best suitable combinations were selected and further studied in small animal models for the soft and hard tissue engineering applications; also its application in the osteochondral integration fields were briefly discussed.

The Impact of the Ionic Cross-Linking Mode on the Physical and In Vitro Dexamethasone Release Properties of Chitosan/Hydroxyapatite Beads.

In this study, the effect of the ionic cross-linking mode on the ability to control physical properties and in vitro release behavior of the dexamethasone (DEX) drug from chitosan (CS) and chitosan/hydroxyapatite (CS/HA) beads was investigated. CS solutions without and with HA and DEX were dripped into two coagulation solutions, prepared with a non-toxic ionic crosslinker (sodium tripolyphosphate, TPP) and distilled water, one at pH = 9.0 and other at pH = 6.0. Optical microscopy (OM) and scanning electron microscopy (SEM) results showed changes on the surface topology of the beads, with a reduction of roughness for beads prepared at pH = 6.0 and an increase for the one prepared at pH = 9.0. The diameter and sphericity of the beads prepared at pH = 6.0 proved more uniform and had a larger pore size with a good interconnectivity framework. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) suggested a higher crosslinking degree for beads prepared at pH = 6.0, corroborated by X-ray diffraction profiles (XRD) analysis that indicated a decrease in the crystalline structure for such beads. In in vitro drug release data, all beads presented a sustained release during the studied period (24 h). The drug release rate was affected by the pH of the coagulation solution used in the preparation of the beads. The in vitro kinetics of the release process was of the Peppas–Sahlin model, controlled by both diffusion and relaxation of polymer chains or swelling (anomalous transport mechanism). Our results suggest that DEX-loaded CS/HA beads, crosslinked in TPP coagulation solution at pH = 9.0, led to a decrease in the DEX release rate and prolonged the release period. Thus, this composition might have prospective as a functional material for bone and cartilage tissue engineering.

Multilayered Titanium Carbide MXene Film for Guided Bone Regeneration.

PurposeMXenes are two-dimensional (2D) materials that are increasingly being applied in biomedical fields. This is ascribed to their good physiochemical properties, unique structure and high biological compatibility. However, the osteogenic activity and suitability of these materials for bone tissue engineering are not clearly understood. Thus, the aim of this study is to evaluate the biocompatibility, osteoinductivity and guided bone regeneration ability of Ti3C2Tx MXene in vitro and in vivo.MethodsMultilayered Ti3C2Tx MXene films were prepared and characterized by XRD and SEM. In vitro experiments were performed to evaluate the effect of MXene films on cell adhesion and morphology with SEM and fluorescence microscopy. The cytotoxicity of MXene films was detected with the Live/Dead double-staining tests. The EdU assay was employed to evaluate cell proliferation on MXene films and ALP activity was tested to determine the effect of the films on osteogenic differentiation in vitro. The mRNA expression of osteogenic differentiation-related markers was measured using qRT-PCR. In vivo animal studies were performed in which the MXene films were implanted subcutaneously in rats to evaluate biocompatibility and host tissue response in vivo. In addition, a rat calvarial defect model was established to examine the bone regeneration performance of the Ti3C2Tx MXene films. The specimens were analyzed with micro-CT evaluation and histological tests.ResultsThe XRD and SEM analyses revealed that the Ti3C2Tx MXene film was successfully synthesized. The cellular experiments showed that MXene films were highly cytocompatible and enhanced osteogenic differentiation in vitro. When implanted into subcutaneous sites and calvarial defect sites in rats, MXene films showed good biocompatibility, osteoinductivity and bone regeneration activity in vivo.ConclusionIn summary, this study presents new applications of MXenes in bone tissue engineering and in guided bone regeneration therapy.

A Biomimicking Polymeric Cryogel Scaffold for Repair of Critical-Sized Cranial Defect in a Rat Model.

Mineralized polymeric cryogels with interconnective macroporous structure have demonstrated their potential as promising scaffolding material in bone tissue engineering. However, their capability in inducing osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro and osteogenesis in vivo has not been explored yet. In this work, the roles of the mineralized cryogel on osteogenesis are systematically studied. Mineralized macroporous poly(ethylene glycol)-co-2-hydroxyethyl methacrylate cryogel promotes osteogenic differentiation of rat MSCs, particularly in upregulating the activity of alkaline phosphatase (ALP, ∼5.7-folds) and expression of related osteogenic gene markers (ALP ∼16-folds, osteocalcin ∼133-folds) at 14 days. In vivo implantation reveals that mineralized cryogels could promote fast osteogenesis and angiogenesis in critical-sized cranial bone defect of a Sprague-Dawley rat model in 4 weeks. The adsorption, entrapment, and concentration of osteogenic growth factors (bone morphogenetic protein 2) and angiogenesis growth factor (vascular endothelial growth factor [VEGF]) in the matrices in vivo may possibly participate in the process of osteogenesis and angiogenesis. Notably, the adsorption of larger amount of VEGF in nonmineralized cryogels facilitates obvious angiogenesis and comparable osteogenesis in bone defect in 8 weeks. Graphical abstract [Figure: see text] Impact Statement The current work reported the fabrication and characterization of a biomimicking mineralized polymeric cryogel as scaffolding material in bone regeneration. In addition to its three dimensional porous structure and the osteogenic potential, this biomimicking scaffold was also found to enhance the adsorption of biochemical cues, which in turn greatly promoted the angiogenesis as well as the tissue regeneration.

Synthesis and Characterization of Chitosan- Polyvinyl alcohol Blend Modified by Genipin and Nanohydroxyapatite for Bone Tissue Engineering

Use nanohydroxyapatite into the polymeric matrix as bioactive material for bone tissue engineering has enormous therapeutic potential because beneficial properties biocompatibility, biodegradability, and consider a major inorganic constituent of the bone matrix. The blended films of Chitosan and Polyvinyl alcohol with Genipin as cross-link agent were studied with and without addition Nanohydroxyapatite. Samples were prepared by solvent casting. The resulting films blended composite were characterized by Fourier transfer infrared (FTIR) spectroscopy, degradation behavior, swelling degree and tensile strength. Degree of swelling, and weight loss of the films blended composite was decreased with an increase of genipin and nanohydroxyapatie concentrations while tensile strength was increased with an increase of genipin and nanohydroxyapaite concentrations. The results showed that the chitosan composite could be used as effective biomaterials for bone regeneration engineering with different degradation rates.

The effect of biomimetic coating and cuttlebone microparticle reinforcement on the osteoconductive properties of cellulose-based scaffolds

Polymer-based scaffolds have already gained popularity in many biomedical applications due to convenient routes for fabrication and favourable structural, physicochemical and functional characteristics. However, polymeric scaffolds lack osteoconductivity and some synthetic polymers carry the risk of inflammatory response caused by degradation by-products. Those facts limit their practical use in bone tissue engineering. In this study, three-dimensional (3D) porous scaffolds from naturally derived polymer, namely regenerated cellulose, were prepared using a non-hydrolytic sol-gel and lyophilization techniques. To induce osteoconductive properties of the polymeric scaffolds, cuttlebone microparticles were immobilized and the surface coating was achieved via in vitro mineralization using 10-fold concentrated simulated body fluid (10x SBF). Biogenic activity of cuttlebone is explained by its chemical composition, which includes polysaccharide β-chitin and macro-, micro- and trace elements favourable for mineralization. Parallel the scaffolds were examined during long-term (24 weeks) in vitro mineralization in 1x SBF for the purpose to investigate apatite-forming ability of the scaffolds. A nice cauliflower-like structures and needle-like dents of the spherical aggregates, which are characteristic to hydroxyapatite precursors, were observed on the surface of cellulose/cuttlebone scaffolds by SEM. 10x SBF coating enhanced cell attachment to the scaffolds because SBF elements are known to increase bioactivity by inducing re-deposition of carbonate apatite crystallites on scaffold surface. Additionally, calcium and phosphate depositions were clearly observed on the developed scaffolds using von Kossa and Alizarin Red S staining. Proliferative and osteoconductive effects on the osteoblast-like MG-63 cells demonstrate the cellulose/cuttlebone scaffolds soaked in 10x SBF as a favourable material for bone tissue engineering.

Arginine based poly (ester amide)/ hyaluronic acid hybrid hydrogels for bone tissue Engineering

Bone transplantations are still facing many serious challenges, hydrogel as a new kind of artificial bone substitutes has developed into a promising bone scaffold material. However, it is still a challenge to combine bioactive agents and hydrogel matrix to promote osteoinductivity. Herein, we developed a novel bioactive hydrogel based on arginine-based unsaturated poly (ester amide) (Arg-UPEA) and methacrylated hyaluronic acid (HA-MA) via photo-crosslinking. As the results indicated, we found that the introduction of Arg-UPEA into HA-MA hydrogels could finely modulate their compressive modulus, swelling level and porous structure. Besides, among groups of different feed ratio, groups of 10 % and 15 % of Arg-UPEA content effectively enhanced osteogenic differentiation in osteoblasts when compared with HA-MA hydrogel. Furthermore, better bone regeneration and expression of osteogenesis-related factors in vivo also verified the Arg-UPEA/HA-MA hybrid hydrogels as a promising scaffold material for bone tissue engineering.

Electroactive composite scaffold with locally expressed osteoinductive factor for synergistic bone repair upon electrical stimulation

Tissue engineering is a promising strategy for the repair of large-scale bone defects, in which scaffolds and growth factors are two critical issues influencing the efficacy of bone regeneration. Unfortunately, the broad application of growth factors is limited by their poor stability in the scaffolds. In the present study, the strictly controlled expression of human bone morphogenetic protein-4 (hBMP-4) in the presence of doxycycline is achieved by adding an hBMP-4 gene fragment into a non-viral artificial restructuring plasmid vector (pSTAR) to form the pSTAR-hBMP-4 plasmid (phBMP-4). Furthermore, the controlled release of phBMP-4 is obtained with an electroactive tissue engineering scaffold, generated by combining a triblock copolymer of poly(l-lactic acid)-block-aniline pentamer-block-poly(l-lactic acid) (PLA-AP) with poly(lactic-co-glycolic acid)/hydroxyapatite (PLGA/HA). This PLGA/HA/PLA-AP/phBMP-4 composite scaffold, with controlled gene release and Dox-regulated gene expression upon electrical stimulation, operating synergistically, exhibits an improved cell proliferation ability, enhanced osteogenesis differentiation in vitro, and effective bone healing in vivo in a rabbit radial defect model. Taking these results together, the proposed smart PLGA/HA/PLA-AP/phBMP-4 scaffold lays a solid theoretical and experimental basis for future applications of such multi-functional materials in bone tissue engineering to help patients in need.

Stretchable poly(glycerol‐sebacate)/β‐tricalcium phosphate composites with shape recovery feature by extrusion

ABSTRACTThere has been a great interest in research towards elastomers and their composites with an attempt to obtain the desired biological and mechanical response to scaffold materials in bone tissue engineering. Composites made of ceramic‐thermoplastic mixtures have been shown success to deliver the inorganic component while fail to provide replacement of an elastic protein, that is, collagen, of the target bone tissue. Thus, in order to match up with the inherent elasticity of the native tissue, it is proposed an alternative to well‐known thermoplastic‐containing matrices by using a poly(glycerol‐sebacate) (PGS)–beta‐tricalcium phosphate elastomeric composite to offer flexibility and mechanical integrity. This study reports for the first time a successful extrusion of PGS containing biodegradable composites with shape‐memory feature. The resulting structures are physically and chemically characterized. In vitro cell culture performance of the obtained materials is investigated by using an MC3T3‐E1 mouse preosteoblast cell line. The materials obtained in this study can be shaped into the desired size and various forms via temperature stimuli. Resulting materials have been proposed for craniofacial tissue engineering as a bone filler in which surgeons need to shape biomaterials during the surgical procedure due to the complex geometry of the bones. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 137, 48689.

Advanced Open-Celled Structures from Low-Temperature Sintering of a Crystallization-Resistant Bioactive Glass.

Most materials for bone tissue engineering are in form of highly porous open-celled components (porosity >70%) developed by means of an adequate coupling of formulations and manufacturing technologies. This paper is dedicated to porous components from BGMS10 bioactive glass, originally designed to undergo viscous flow sintering without crystallization, which is generally known to degrade the bioactivity of 45S5 bioglass. The adopted manufacturing technologies were specifically conceived to avoid any contamination and give excellent control on the microstructures by simple operations. More precisely, ‘green’ components were obtained by digital light processing and direct foaming of glass powders suspended in a photosensitive organic binder or in an aqueous solution, activated with an organic base, respectively. Owing to characteristic quite large sintering window of BGMS10 glass, sintering at 750 °C caused the consolidation of the structures generated at room temperature, without any evidence of viscous collapse.