Potential Bone Tissue Engineering Research Articles

The Investigation of ZnO/Poly(vinylidene fluoride) Nanocomposites with Improved Mechanical, Piezoelectric, and Antimicrobial Properties for Orthopedic Applications.

Studies have shown that piezoelectric materials can be used as bioactively charged surfaces to induce tissue regeneration (like bone reconstruction). β-phase poly(vinylidene fluoride) (PVDF) and zinc oxide (ZnO) are regarded as potential bone tissue engineering materials because of their piezoelectricity and biocompatibility. Additionally, ZnO nanoparticles (NPs) are ideal materials to reduce infection. In this study, PVDF scaffolds doped with ZnO NPs (ZnO/PVDF) were prepared by electrospinning increasing ZnO concentrations and the ratio of the β-phase PVDF resulting in an enhanced the modulus, elongation to failure and load stress. In vitro osteoblast assays were also performed to determine material cytotoxicity and bone reconstruction potential. Results exhibited that the piezo-excited scaffolds had a 30% greater osteoblast density, compared to non-piezoelectric-excited groups after 3 days of culture. To evaluate the scaffold's antimicrobial properties, three common etiologic agents of orthopedic after-surgery infection, Staphylococcus aureus (SA), Methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), were separately seeded and counted. Results of this in vitro study showed significantly reduced E. coli (45%), SA (48%) and MRSA (37%) density on the 1 mg/ml ZnO/PVDF scaffolds without piezo-excitation (compared to the control). Moreover, compared to the non-piezo-excited scaffolds, results showed for the first time that the density of the same bacteria on the piezo-excited scaffolds reduced by over 23%, 22%, and 33%, respectively. For the first time, the effects of novel ZnO/PVDF scaffolds on osteoblasts and bacteria were investigated here, and significantly decreased bacteria with increased osteoblast density on the piezo-excited scaffolds demonstrated that these scaffolds have a strong potential for numerous antibacterial orthopedic applications.

A 3D bioprinted in situ conjugated-co-fabricated scaffold for potential bone tissue engineering applications.

There is a demand for progressive approaches in bone tissue engineering to repair and regenerate bone defects resulting from trauma or disease. This investigation sought to engineer a single-step in situ conjugated polymeric scaffold employing 3D printing technology as an innovative fabricating tool. A polymeric scaffold was engineered in situ employing sodium alginate as a bio-ink which interacted with a poly(ethyleneimine) solution on bioprinting to form a polyelectrolyte complex through ionic bond formation. Silica gel was included in the bio-ink as temporal inorganic support component and for ultimate enhancement of osteoinduction. Characterization of the biorelevant properties of the scaffold was undertaken via Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry and Thermogravimentric Analysis, X-Ray diffraction, Scanning Electron Microscopy, and biomechanical testing. The scaffold maintained its 3D architecture for the duration of the 28-day degradation investigation, while potentially permitting the infiltration of nutrients, growth factor, and cells evident by the increased solvent penetration into the scaffold observed via Magnetic Resonance Imaging studies. The scaffold porosity and pore size were found to be 60% and 360 µm, respectively. Biomechanical evaluation revealed a Young's modulus of 18.37 MPa highlighting that the scaffold in its current form possesses the mechanical capabilities for certain bone tissue engineering applications. This investigation provided highlighted the applicability of alginate-poly(ethyeneimine)/silica for 3D bioprinting as a scaffold which could possess potential as a bone tissue engineering scaffold. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1311-1321, 2018.

The promoting effect on pre-osteoblast growth under electrical and magnetic double stimulation based on PEDOT/Fe3O4/PLGA magnetic-conductive bi-functional scaffolds.

Electrical stimulation (ES) and magnetic stimulation (MS) can promote bone tissue formation in vivo. Loading ES and MS simultaneously would be very beneficial for bone tissue construction in vitro or in vivo. Magnetic-conductive bi-functional scaffolds which are favorable for the transfer of ES and MS, could further facilitate bone cell/tissue growth. Poly(3,4-ethylenedioxythiophene) (PEDOT)/Fe3O4/polylactic acid-co-glycolic acid (PLGA) magnetic-conductive bi-functional fibrous scaffolds were prepared through in situ polymerization of EDOT on Fe3O4/PLGA fibers. MC3T3-E1 pre-osteoblasts were incubated on the PEDOT/Fe3O4/PLGA fibrous scaffolds and were stimulated by electrical, magnetic and electrical-magnetic signals respectively to detect the impact of different stimulation on cell viability. The measured results show that the scaffolds possess good conductivity and superparamagnetic responsiveness. Furthermore, both electrical and magnetic stimulation promoted cell proliferation and magnetic stimulation could induce cell alignment arrangement. Meanwhile, under electrical-magnetic double stimulation, cell viability was much higher than for cells under single electrical or magnetic stimulation. The growth promoting effects of PEDOT/Fe3O4/PLGA fibrous scaffolds under electrical-magnetic double stimulation has great practical potential for bone tissue engineering.

Fabrication of Novel Silk Fibroin - LDHs Composite Arhitectures for Potential Bone Tissue Engineering

Nanocomposite materials have attracted a high interest for biomedical applications because their special properties related with structure and composition. In this paper we synthesized novel hydrogel nanocomposite materials special designed for hard tissue engineering. The nanocomposite materials are able to promote hydroxyapatite formation by alternating soaking mineralization demanded for increasing of cells biocompatibility and adhesion.

Evaluation of the in vitro biodegradation and biological behavior of poly(lactic-co-glycolic acid)/nano-fluorhydroxyapatite composite microsphere-sintered scaffold for bone tissue engineering

The objective of this research was to study the degradation and biological characteristics of the three-dimensional porous composite scaffold made of poly(lactic- co-glycolic acid)/nano-fluorhydroxyapatite microsphere using sintering method for potential bone tissue engineering. Our previous experimental results demonstrated that poly(lactic- co-glycolic acid)/nano-fluorhydroxyapatite composite scaffold with a ratio of 4:1 sintered at 90ºC for 2 h has the greatest mechanical properties and a proper pore structure for bone repair applications. The weight loss percentage of both poly(lactic- co-glycolic acid)/nano-fluorhydroxyapatite and poly(lactic- co-glycolic acid) scaffolds demonstrated a monotonic trend with increasing degradation time, that is, the incorporation of nano-fluorhydroxyapatite into polymeric scaffold could lead to weight loss in comparison with that of pure poly(lactic- co-glycolic acid). The pH change for composite scaffolds showed that there was a slight decrease until 2 weeks after immersion in simulated body fluid, followed by a significant increase in the pH of simulated body fluid without a scaffold at the end of immersion time. The mechanical properties of composite scaffold were higher than that of poly(lactic- co-glycolic acid) scaffold at total time of incubation in simulated body fluid; however, it should be noted that the incorporation of nano-fluorhydroxyapatite into composite scaffold leads to decline in the relatively significant mechanical strength and modulus during hydrolytic degradation. In addition, MTT assay and alkaline phosphatase activity results defined that a general trend of increasing cell viability was seen for poly(lactic- co-glycolic acid)/nano-fluorhydroxyapatite scaffold sintered by time when compared to control group. Eventually, experimental results exhibited poly(lactic- co-glycolic acid)/nano-fluorhydroxyapatite microsphere-sintered scaffold is a promising scaffold for bone repair.

Fabrication of Electrospun 3D Nanofibrous Poly(3-Hydroxybutyrate-Co-4-Hydroxybutyrate)/Graphene Scaffolds for Potential Bone Tissue Engineering: Effects of Graphene on Scaffold Properties and Cellular Behaviors

Fabrication of Electrospun 3D Nanofibrous Poly(3-Hydroxybutyrate-Co-4-Hydroxybutyrate)/Graphene Scaffolds for Potential Bone Tissue Engineering: Effects of Graphene on Scaffold Properties and Cellular Behaviors

Cryogenic 3D printing for producing hierarchical porous and rhBMP-2-loaded Ca-P/PLLA nanocomposite scaffolds for bone tissue engineering

The performance of bone tissue engineering scaffolds can be assessed through cell responses to scaffolds, including cell attachment, infiltration, morphogenesis, proliferation, differentiation, etc, which are determined or heavily influenced by the composition, structure, mechanical properties, and biological properties (e.g. osteoconductivity and osteoinductivity) of scaffolds. Although some promising 3D printing techniques such as fused deposition modeling and selective laser sintering could be employed to produce biodegradable bone tissue engineering scaffolds with customized shapes and tailored interconnected pores, effective methods for fabricating scaffolds with well-designed hierarchical porous structure (both interconnected macropores and surface micropores) and tunable osteoconductivity/osteoinductivity still need to be developed. In this investigation, a novel cryogenic 3D printing technique was investigated and developed for producing hierarchical porous and recombinant human bone morphogenetic protein-2 (rhBMP-2)-loaded calcium phosphate (Ca-P) nanoparticle/poly(L-lactic acid) nanocomposite scaffolds, in which the Ca-P nanoparticle-incorporated scaffold layer and rhBMP-2-encapsulated scaffold layer were deposited alternatingly using different types of emulsions as printing inks. The mechanical properties of the as-printed scaffolds were comparable to those of human cancellous bone. Sustained releases of Ca2+ ions and rhBMP-2 were achieved and the biological activity of rhBMP-2 was well-preserved. Scaffolds with a desirable hierarchical porous structure and dual delivery of Ca2+ ions and rhBMP-2 exhibited superior performance in directing the behaviors of human bone marrow-derived mesenchymal stem cells and caused improved cell viability, attachment, proliferation, and osteogenic differentiation, which has suggested their great potential for bone tissue engineering.

Ag-loaded MgSrFe-layered double hydroxide/chitosan composite scaffold with enhanced osteogenic and antibacterial property for bone engineering tissue.

Bone tissue engineering scaffolds for the reconstruction of large bone defects should simultaneously promote osteogenic differentiation and avoid postoperative infection. Herein, we develop, for the first time, Ag-loaded MgSrFe-layered double hydroxide/chitosan (Ag-MgSrFe/CS) composite scaffold. This scaffold exhibits three-dimensional interconnected macroporous structure with a pore size of 100-300 μm. The layered double hydroxide nanoplates in the Ag-MgSrFe/CS show lateral sizes of 200-400 nm and thicknesses of ∼50 nm, and the Ag nanoparticles with particle sizes of ∼20 nm are uniformly dispersed on the scaffold surfaces. Human bone marrow-derived mesenchymal stem cells (hBMSCs) present good adhesion, spreading, and proliferation on the Ag-MgSrFe/CS composite scaffold, suggesting that the Ag and Sr elements in the composite scaffold have no toxicity to hBMSCs. When compared with MgFe/CS composite scaffold, the Ag-MgSrFe/CS composite scaffold has better osteogenic property. The released Sr2+ ions from the composite scaffold enhance the alkaline phosphatase activity of hBMSCs, promote the extracellular matrix mineralization, and increase the expression levels of osteogenic-related RUNX2 and BMP-2. Moreover, the Ag-MgSrFe/CS composite scaffold possesses good antibacterial property because the Ag nanoparticles in the composite scaffold effectively prevent biofilm formation against S. aureus. Hence, the Ag-MgSrFe/CS composite scaffold with excellent osteoinductivity and antibacterial property has a great potential for bone tissue engineering. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 863-873, 2018.

Effects of the donor age on proliferation, senescence and osteogenic capacity of human urine-derived stem cells.

To study the effects of the donor age on the application potential of human urine-derived stem cells (hUSCs) in bone tissue engineering, by comparing proliferation, senescence and osteogenic differentiation of hUSCs originated from volunteers with different ages. The urine samples were collected from 19 healthy volunteers (6 cases from children group aged from 5 to 14, 5 cases from middle-aged group aged from 30 to 40, and 8 cases from the elder group aged from 65 to 75), and hUSCs were isolated and cultured. The cell morphology was observed by microscope and the cell surface markers were identified by flow cytometry. Their abilities to undergo osteogenic, adipogenic and chondrogenic differentiation were determined in vitro, and cell proliferation analyses were performed using Cell Counting Kit-8 (CCK8) Assay. The senescence of hUSCs among three groups was assessed by senescence-associated β galactosidase staining. After osteogenic differentiation, the alkaline phosphatase (ALP) activity of hUSCs was measured and expression of osteogenic-related runt-related transcription factor 2 (RUNX2) and osteocalcin (OCN) was determined by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. The hUSCs isolated from urine samples were adherent cells displayed "rice gain"-like and "spindle-shaped" morphology, expressing surface markers of mesenchymal stem cells (MSCs) (CD73, CD90, CD105) and the peripheral cell marker (CD146), but not hematopoietic stem cell markers (CD34, CD45) or the embryonic stem cell marker (OCT3/4). The obtained hUSCs could be induced into osteogenic, adipogenic or chondrogenic differentiation. The hUSCs from the children group showed higher proliferation and lower tendency to senescence than those from the middle-aged and elder groups. After osteogenic induction, the ALP activity and RUNX2 and OCN expression of hUSCs from the children group were higher than those from the elder group. While no significant differences were observed when comparing the middle-aged group with the children group or the elder group. Donor age could influence the potency of hUSCs on proliferation, senescence and capacity of osteogenic differentiation. hUSCs from children group have shown higher proliferation, lower tendency to senescence, and stronger osteogenic capacity, which means to be more suitable for basic research and have better clinical application. Furthermore, hUSCs from all groups suggest the application potential in bone tissue engineering as seed cells.

Local application of lactoferrin promotes bone regeneration in a rat critical-sized calvarial defect model as demonstrated by micro-CT and histological analysis.

Lactoferrin is a multifunctional glycoprotein with therapeutic potential for bone tissue engineering. The aim of this study was to assess the efficacy of local application of lactoferrin on bone regeneration. Five‐millimetre critical‐sized defects were created over the right parietal bone in 64 Sprague–Dawley rats. The rats were randomized into four groups: group 1 (n = 20) had empty defects; group 2 (n = 20) had defects grafted with collagen gels (3 mg/ml); group 3 (n = 20) had defects grafted with collagen gels impregnated with bovine lactoferrin (10 μg/gel); and group 4 (n = 4) had sham surgeries (skin and periosteal incisions only). The rats were sacrificed at 4 or 12 weeks post‐operatively, and the calvaria were excised and evaluated with micro‐CT (Skyscan 1172) followed by histology. The bone volume fraction (BV/TV) was higher in lactoferrin‐treated animals at both timepoints, with groups 1, 2, 3 and 4 measuring 10.5 ± 1.1%, 8.6 ± 1.4%, 16.5 ± 0.6% and 24.27 ± 2.6%, respectively, at 4 weeks (P < 0.05); and 12.2 ± 1.3%, 13.6 ± 1.5%, 21.9 ± 1.2% and 29.3 ± 0.8%, respectively, at 12 weeks (P < 0.05). Histological analysis revealed that the newly formed bone within the calvarial defects of all groups was a mixture of woven and lamellar bone, with more bone in the group treated with lactoferrin at both timepoints. Our study demonstrated that local application of lactoferrin significantly increased bone regeneration in a rat critical‐sized calvarial defect model. The profound effect of lactoferrin on bone regeneration has therapeutic potential to improve the poor clinical outcomes associated with bony non‐union. LF In Vivo JTERM Authors Contributions. Copyright © 2016 The Authors Journal of Tissue Engineering and Regenerative Medicine Published by John Wiley & Sons, Ltd.

Controlled Release of Vanadium from a Composite Scaffold Stimulates Mesenchymal Stem Cell Osteochondrogenesis.

Large bone defects often require the use of autograft, allograft, or synthetic bone graft augmentation; however, these treatments can result in delayed osseous integration. A tissue engineering strategy would be the use of a scaffold that could promote the normal fracture healing process of endochondral ossification, where an intermediate cartilage phase is later transformed to bone. This study investigated vanadyl acetylacetonate (VAC), an insulin mimetic, combined with a fibrous composite scaffold, consisting of polycaprolactone with nanoparticles of hydroxyapatite and beta-tricalcium phosphate, as a potential bone tissue engineering scaffold. The differentiation of human mesenchymal stem cells (MSCs) was evaluated on 0.05 and 0.025wt% VAC containing composite scaffolds (VAC composites) in vitro using three different induction media: osteogenic (OS), chondrogenic (CCM), and chondrogenic/osteogenic (C/O) media, which mimics endochondral ossification. The controlled release of VAC was achieved over 28days for the VAC composites, where approximately 30% of the VAC was released over this period. MSCs cultured on the VAC composites in C/O media had increased alkaline phosphatase activity, osteocalcin production, and collagen synthesis over the composite scaffold without VAC. In addition, gene expressions for chondrogenesis (Sox9) and hypertrophic markers (VEGF, MMP-13, and collagen X) were the highest on VAC composites. Almost a 1000-fold increase in VEGF gene expression and VEGF formation, as indicated by immunostaining, was achieved for cells cultured on VAC composites in C/O media, suggesting VAC will promote angiogenesis in vivo. These results demonstrate the potential of VAC composite scaffolds in supporting endochondral ossification as a bone tissue engineering strategy.

A novel comby scaffold with improved mechanical strength for bone tissue engineering

Porous scaffold is an integral part of bone tissue engineering. However, low mechanical strength is a major challenge. A biomimetic comby scaffold was designed to get an improvement of strength in this paper. Fabrication of this bone scaffold involved first creating a pore-forming mold by using three-dimensional printing (3DP), which was cast into chitosan/nano-hydroxyapatite (CS/nHA) powders to create an inverse mold. The sacrificial mold and inverse one were then pressed by cold isostatic pressing as a whole in order to enhance the strength. Finally, the wax template was removed, resulting in a scaffold with honeycomb geometry. Compression tests were carried out to evaluate the strength of the scaffold. The behaviors and responses of preosteoblast cells on the scaffold were studied as well. The scaffold with high porosity were found to display improved compressive strength (1.62±0.22MPa) and Young’s modulus (110±22Mpa) approaching the values of cancellous bone. Moreover, MC3T3-E1 cells exhibited good proliferation on the scaffold. The comby scaffold had great application potential in bone tissue engineering. This novel structural bionic approach would offer some new ideas in design and fabrication of porous scaffolds for tissue engineering.

Fabrication of porous bioceramics for bone tissue applications using luffa cylindrical fibres (LCF) as template

Three-dimensionally orderedmacroporous biomaterials containing hydroxyapatite were synthesized using natural luffa cylindrical fibres (with diameter of 100-400 μm) as templates. The preliminary evaluation of this novel method for production of porous bioceramics showed promising potential applications in bone tissue engineering. The produced bioceramics were subjected to microstructural, physical, mechanical, and in vitro characterisation. Mercury intrusion porosimetry, supported by SEM analysis, showed the presence of bimodal porosity (smaller pores with diameters of 10 to 30 μm and cylindrical macropores with diameters from 100 to 400 μm) and 60% of the interconnected porosity. These porous calcium phosphate ceramics proved to be bioactive and exhibited mechanical properties comparable to those of natural spongy bones with compressive strength up to 3MPa and elastic modulus in compression around 0.05GPa. In vitro characterization of the porous ceramics showed cells attaching to the apatite crystals that make up the scaffold matrix. Cell adhesion resulted in elongated and highly stretched cells within the macropores with focal adhesion points on the scaffolds. Moreover, the cells adhered to the calcium phosphate cement (CPC) and developed cytoplasmic extensions as shown by SEM imagery. Their proliferation in the scaffolds in culture demonstrates that the scaffold architecture is suitable for Mesenchymal stem cells seeding and growth.

Development of Novel Biocomposite Scaffold of Chitosan-Gelatin/Nanohydroxyapatite for Potential Bone Tissue Engineering Applications.

In this study, a three-dimensional chitosan-gelatin/nanohydroxyapatite (ChG/nHaP) scaffold was successfully fabricated and characterized in terms of swelling, degradation, cell proliferation, cell attachment, and mineralization characterizations. The ChG/nHaP scaffold was fabricated with a mean pore size of 100–180 μm. Our results showed that the physicochemical and biological properties of the scaffolds were affected by the presence of HaP. The swelling and degradation characteristics of the ChG scaffold were remarkably decreased by the addition of HaP. On the other hand, the presence of HaP remarkably improved the MC3T3-E1 cell attachment and cell growth in the scaffold membrane. The biocompatible nature of the ChG/nHaP scaffold leads to the development of finely scaled mineral deposits on the scaffold membrane. Thus, HaP played an important role in improving the biological performance of the scaffold. Therefore, the ChG/nHaP scaffold could be applied as a suitable material for bone tissue engineering applications.

Hydrogel fibers encapsulating human stem cells in an injectable calcium phosphate scaffold for bone tissue engineering

Human induced pluripotent stem cells (hiPSCs), human embryonic stem cells (hESCs) and human umbilical cord mesenchymal stem cells (hUCMSCs) are exciting cell sources for use in regenerative medicine. There have been no reports on long hydrogel fibers encapsulating stem cells inside an injectable calcium phosphate cement (CPC) scaffold for bone tissue engineering. The objectives of this study were: (1) to develop a novel injectable CPC construct containing hydrogel fibers encapsulating cells for bone engineering, and (2) to investigate and compare cell viability, proliferation and osteogenic differentiation of hiPSC-MSCs, hESC-MSCs and hUCMSCs in injectable CPC. The pastes encapsulating the stem cells were fully injectable under a small injection force, and the injection did not harm the cells, compared with non-injected cells (p > 0.1). The mechanical properties of the stem cell–CPC construct were much better than those of previous injectable polymers and hydrogels for cell delivery. The hiPSC-MSCs, hESC-MSCs and hUCMSCs in hydrogel fibers in CPC had excellent proliferation and osteogenic differentiation. All three cell types yielded high alkaline phosphatase, runt-related transcription factor, collagen I and osteocalcin expression (mean ± SD; n = 6). Cell-synthesized minerals increased substantially with time (p < 0.05), with no significant difference among the three types of cells (p > 0.1). Mineralization by hiPSC-MSCs, hESC-MSCs and hUCMSCs in CPC at 14 d was 13-fold that at 1 d. In conclusion, all three types of cells (hiPSC-MSCs, hESC-MSCs and hUCMSCs) in a CPC scaffold showed high potential for bone tissue engineering, and the novel injectable CPC construct with cell-encapsulating hydrogel fibers is promising for enhancing bone regeneration in dental, craniofacial and orthopedic applications.

Investigating the potential of combined growth factors delivery, from non-mulberry silk fibroin grafted poly(ɛ-caprolactone)/hydroxyapatite nanofibrous scaffold, in bone tissue engineering

Mineralized scaffolds have the advantage of better mimicking the natural bone structure and thus show an improved potential for bone tissue engineering. This study uses cycles of alternative soaking to deposit hydroxyapatite (HAp) layers upon non-mulberry silk fibroin (from Antheraea mylitta) grafted poly(ɛ-caprolactone) nanofibrous matrices. Alternate soaking, of one through three cycles, is used due to its simplicity and deposition efficiency. HAp deposition improved mechanical strength of the scaffolds up to two cycles of soaking (by nearly 75%). Analysis of mechanical properties, bioactivity and in vitro study results (with MG-63 cell line) showed scaffolds fabricated using two-cycle soaking to be the most suitable. These constructs were loaded with growth factors (transforming growth factor beta (TGF-β) 4ng and bone morphogenic protein-2 (rhBMP-2) 100ng) using carbodiimide-coupling reaction. The following three different combinations of growth factor loaded composites were analyzed: solely rhBMP-2, solely TGF-β and rhBMP-2-TGF-β combinations. Scaffolds with both growth factors supported cellular activity and proliferation better (p<0.01), generated greater calcium deposits (p<0.01), facilitated early cell differentiation and yielded significantly better expression of genes linked to bone growth (p<0.05). These dual growth factor loaded scaffolds are mechanically robust and enhance cell proliferation and early differentiation of osteoblast-like cells. They thus show potential of being further optimized for use in bone tissue engineering.

Natural origin hydroxyapatite scaffold as potential bone tissue engineering substitute

Fish scales derived natural hydroxyapatite (FS-HAp) scaffolds were prepared through solvent casting technique, which could mimic the structure of cortical and cancellous bone tissues of body system. The hydroxyapatite (HAp) biomaterial was synthesized by thermal decomposition of chemically treated fish scales. Fabricated scaffolds were characterized through morphological analysis, volumetric shrinkage, mechanical tests, and in vitro, in vivo biological studies. The projected scaffolds successfully mimic the cancellous/cortical bone system in terms of structure, porosity, mechanical strength, and exhibit excellent bioactive behavior. The FS-HAp scaffolds manifest good mechanical behaviors with Vickers Hardness (HV) of ~0.78GPa, 0.52GPa compressive stress, 190MPa tensile stress and ~35% porosity on sintering at 1200°C. In vitro and in vivo studies suggest these nontoxic HAp scaffolds graft with osteoconductive support, facilitating new cell growth on the developed scaffold surface. The graded grafts have a great potential for application as traumatized tissue augmentation substitute, and ideal for load-bearing bone applications.

Novel polyvinyl alcohol-bioglass 45S5 based composite nanofibrous membranes as bone scaffolds

Composite nanofibrous membranes based on sol-gel derived 45SiO2 24.5CaO 24.5 Na2O 6 P2O5 (bioglass, BG) and 43SiO2 24.5CaO 24.5 Na2O 6 P2O5 2Fe2O3 (magnetic bioglass, MBG) blended with polyvinyl alcohol (PVA) have been electrospun. These low cost membranes were mostly amorphous in structure with minor crystalline (sodium calcium phosphate) precipitates. All membranes were biodegradable. Among these, the composites exhibited higher tensile strength, better proliferation of human osteosarcoma MG63 cells and higher alkaline phosphatase enzyme activity than the bare PVA membrane, indicating their potential in bone tissue engineering. The magnetic PVA-MBG scaffold was also found to be a promising candidate for magnetic hyperthermia application.

Minocycline Loaded Hybrid Composites Nanoparticles for Mesenchymal Stem Cells Differentiation into Osteogenesis.

Bone transplants are used to treat fractures and increase new tissue development in bone tissue engineering. Grafting of massive implantations showing slow curing rate and results in cell death for poor vascularization. The potentials of biocomposite scaffolds to mimic extracellular matrix (ECM) and including new biomaterials could produce a better substitute for new bone tissue formation. A purpose of this study is to analyze polycaprolactone/silk fibroin/hyaluronic acid/minocycline hydrochloride (PCL/SF/HA/MH) nanoparticles initiate human mesenchymal stem cells (MSCs) proliferation and differentiation into osteogenesis. Electrospraying technique was used to develop PCL, PCL/SF, PCL/SF/HA and PCL/SF/HA/MH hybrid biocomposite nanoparticles and characterization was analyzed by field emission scanning electron microscope (FESEM), contact angle and Fourier transform infrared spectroscopy (FT-IR). The obtained results proved that the particle diameter and water contact angle obtained around 0.54 ± 0.12 to 3.2 ± 0.18 µm and 43.93 ± 10.8° to 133.1 ± 12.4° respectively. The cell proliferation and cell-nanoparticle interactions analyzed using (3-(4,5-dimethyl thiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium inner salt) MTS assay (Promega, Madison, WI, USA), FESEM for cell morphology and 5-Chloromethylfluorescein diacetate (CMFDA) dye for imaging live cells. Osteogenic differentiation was proved by expression of osteocalcin, alkaline phosphatase activity (ALP) and mineralization was confirmed by using alizarin red (ARS). The quantity of cells was considerably increased in PCL/SF/HA/MH nanoparticles when compare to all other biocomposite nanoparticles and the cell interaction was observed more on PCL/SF/HA/MH nanoparticles. The electrosprayed PCL/SF/HA/MH biocomposite nanoparticle significantly initiated increased cell proliferation, osteogenic differentiation and mineralization, which provide huge potential for bone tissue engineering.

Glycol chitosan/nanohydroxyapatite biocomposites for potential bone tissue engineering and regenerative medicine

In the last few decades, research on biocomposite nanomaterials has grown exponentially due to the global demand for novel solutions in bone tissue engineering and repair. In the present study, it is reported the design and synthesis of biocomposites based on glycol chitosan (GLY-CHI) matrices incorporated with nano-hydroxyapatite particles (nHA) produced via an eco-friendly chemical colloidal process in water media followed by solvent casting and evaporation methods at room temperature. The structure, morphology, and crystallinity of the components and biocomposites were extensively characterized by light microscopy (LM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), wavelength dispersive X-ray fluorescence spectroscopy (WD-XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray micro-computed tomography analysis (μCT). Furthermore, cytotoxicity and cell viability tests were performed on three cell lines using a 3-(4,5-dimethylthiazol-2yl) 2,5-diphenyl tetrazolium bromide (MTT) assay, an alkaline phosphatase (ALP) activity test, and LIVE/DEAD® assays. The results demonstrated that the GLY-CHI ligand played a major role in the nucleation, growth and colloidal stabilization of calcium phosphate particles at nanoscale dimensions with a narrow distribution and average size of 74±15nm. The FTIR spectroscopy associated with the XRD results indicated that nanosized hydroxyapatite (nHA) was the predominant calcium phosphate phase produced in the colloidal processing route. In addition, the X-ray micro-CT analysis of the nanocomposite membranes showed that nHA particles were homogenously dispersed in the glycol-chitosan polymeric matrix. Moreover, according to the in vitro bioassays, the biocomposites showed an adequate cell viability response and non-cytotoxic behavior toward osteoblastic-like (SAOS) and embryonic cell lines (HEK293T). Finally, the results of osteogenic differentiation tests demonstrated that the nHA/GLY-CHI composites are osteoinductive for human bone marrow mesenchymal stem cells (HBMS), which can be envisioned for prospective use in tissue engineering (e.g., bone, cartilage and periodontal) applications.