In vitro investigations on the effects of graphene and graphene oxide on polycaprolactone bone tissue engineering scaffolds

Polycaprolactone(PCL)scaffolds that are produced through additive manufacturing are one of the most researched bone tissue engineering structures in the field.Due to the intrinsic limitations of PCL,carbon nanomaterials are often investigated to reinforce the PCL scaffolds.Despite several studies that have been conducted on carbon nanomaterials,such as graphene(G)and graphene oxide(GO),certain challenges remain in terms of the precise design of the biological and nonbiological properties of the scaffolds.This paper addresses this limitation by investigating both the nonbiological(element composition,surface,degradation,and thermal and mechanical properties)and biological characteristics of carbon nanomaterial-reinforced PCL scaffolds for bone tissue engineering applications.Results showed that the incorporation of G and GO increased surface properties(reduced modulus and wettability),material crystallinity,crystallization temperature,and degradation rate.However,the variations in compressive modulus,strength,surface hardness,and cell metabolic activity strongly depended on the type of reinforcement.Finally,a series of phenomenological models were developed based on experimental results to describe the variations of scaffold’s weight,fiber diameter,porosity,and mechanical properties as functions of degradation time and carbon nanomaterial concentrations.The results presented in this paper enable the design of three-dimensional(3D)bone scaffolds with tuned properties by adjusting the type and concentration of different functional fillers.

Magnesium-incorporated biocomposite scaffolds:A novel frontier in bone tissue engineering

Nonunion represents a crucial challenge in orthopedic medicine,demanding innovative solutions beyond the scope of traditional bone grafting methods.Among the various strategies available,magnesium(Mg)implants have been recognized for their biocompatibility and biodegradability.However,their susceptibility to rapid corrosion and degradation has garnered notable research interest in bone tissue engineering(BTE),particularly in the development of Mg-incorporated biocomposite scaffolds.These scaffolds gradually release Mg2+,which enhances immunomodulation,osteogenesis,and angiogenesis,thus facilitating effective bone regeneration.This review presents myriad fabrication techniques used to create Mg-incorporated biocomposite scaffolds,including electrospinning,three-dimensional printing,and sol-gel synthesis.Despite these advancements,the application of Mg-incorporated biocomposite scaffolds faces challenges such as controlling the degradation rate of Mg and ensuring mechanical stability.These limitations highlight the necessity for ongoing research aimed at refining fabrication techniques to better regulate the physicochemical and osteogenic properties of scaffolds.This review provides insights into the potential of Mg-incorporated biocomposite scaffolds for BTE and the challenges that need to be addressed for their successful translation into clinical applications.

Interplay between mesenchymal stem cells and macrophages:Promoting bone tissue repair

The repair of bone tissue damage is a complex process that is well-orchestrated in time and space,a focus and difficulty in orthopedic treatment.In recent years,the success of mesenchymal stem cells(MSCs)-mediated bone repair in clinical trials of large-area bone defects and bone necrosis has made it a candidate in bone tissue repair engineering and regenerative medicine.MSCs are closely related to macrophages.On one hand,MSCs regulate the immune regulatory function by influencing macrophages proliferation,infiltration,and phenotype polarization,while also affecting the osteoclasts differentiation of macrophages.On the other hand,macrophages activate MSCs and mediate the multilineage differentiation of MSCs by regulating the immune microenvironment.The cross-talk between MSCs and macrophages plays a crucial role in regulating the immune system and in promoting tissue regeneration.Making full use of the relationship between MSCs and macrophages will enhance the efficacy of MSCs therapy in bone tissue repair,and will also provide a reference for further application of MSCs in other diseases.

Role of immune relevant factors in regenerative processes of bone tissue: a bibliometric and visualized analysis

Background:There is a deficiency of bibliometric and visually represented analysis in research on the immunological related variables involved in bone tissue regeneration.Using bibliometric and visual analysis,this study sought to thoroughly examine the hotspots and future directions in the investigation of immunological important variables in bone tissue regeneration.Methods:The Web of Science Core Collection(WoSCC)database was searched and a collection of published works on the subject of immunological related factors in bone tissue regeneration between 2000 and 2021 was generated.The data chosen from the WoSCC were then subjected to a systematic bibliometric and visualized analysis using the online bibliometric analytics system,Apache ECharts,VOSviewer,Bibliographic Items Co-occurrence Matrix Builder 2.0,and Gcluto 1.0.Results:For this investigation,1,088 publications on the involvement of immune related components in bone tissue regeneration were chosen.Between 2000 and 2021,China maintained its supremacy in global research on the function of immune related components in bone tissue regeneration.Shanghai Jiao Tong University is the most productive institution.Biomaterials has published the most publications on the involvement of immune-related components in bone tissue regeneration.Xiao Y,Schmidt-Bleek K,and Ignatius A all played important roles in the study of immune-related variables in bone tissue regeneration.Research on the role of immune relevant factors in bone tissue regeneration has identified five hotspots:(1)macrophage-based immunomodulation on osteogenesis of mesenchymal stem cells(MSCs);(2)biomaterials for bone repair in bone tissue engineering;(3)osteoimmunomodulation mediated by inflammation and macrophages during bone healing;(4)osteoimmunomodulation in angiogenesis during bone regeneration;and(5)the effect of macrophage polarization regulated by bone tissue engineering on osteogenic differentiation of MSCs as bone tissue.Conclusion:This study represents the first-ever bibliometric and visualized examination of how immune factors contribute to bone tissue regeneration.The focus and forthcoming direction in bone regeneration research will be on macrophage-driven immunomodulation in the process of bone regeneration.

The fabrication of hydroxyapatite mineralized hydrogels for bone tissue engineering

Bone is a complex but orderly mineralized tissue with hydroxyapatite(HA)as the inorganic phase and collagen as the organic phase.Inspired by natural bone tissues,HA-mineralized hydrogels have been widely designed and used in bone tissue engineering.HA is majorly utilized for the treatment of bone defects because of its excellent osteoconduction and bone inductivity.Hydrogel is a three-dimensional hydrophilic network structure with similar properties to the extracellular matrix(ECM).The combination of HA and hydrogels produces a new hybrid material that could effectively promote osteointegration and accelerate the healing of bone defects.In this review,the structure and growth of bone and the common strategies used to prepare HA were briefly introduced.Importantly,we discussed the fabrication of HA mineralized hydrogels from simple blending to in situ mineralization.We hope this review can provide a reference for the development of bone repair hydrogels.

Effects of Fascial Manipulative Treatment on Bone Tissue

The experimental research, presented in this study, focuses on athletic tests with the purpose to highlight the elastic deformations of the bones of the lower limbs, intending to verify whether the manually treated anatomical structure increases in elasticity, becoming able to accumulate more energy in the loading phase, to then release it in the final phase of the thrust. Introduction: Too often neglected, the bone tissue is capable of deforming. The deformation has a key role in the cushioning and dissipation of stress, a function that is hindered in the event of fascial tension, which will consequently fall on other structures used for the same purpose (Discs, menisci, cartilage, …). Structures that, in the event of increased mechanical stress, could undergo degeneration, inflammation, and injury. Materials and Method: Randomized double-blind selection of 38 people, 18 in the treatment group and 20 in the control group, men and women, aged between 16 and 35, who have been part, for at least one year, of a sports club, with a large space dedicated to jumping in its training program, have been divided into two groups: the treatment group, which was treated to increase the performance of the jump and the control group subjected to mild manual pressures, without any intention. Results: The treatment group had an increase in Standing Long Jump (SLJ) for 3.67% (p Conclusions: This study has shown that an osteopathic manipulative treatment, aimed at increasing jumping performance, can increase the performance of the SLJ.

Study on β-TCP Coated Porous Mg as a Bone Tissue Engineering Scaffold Material

Three-dimensional honeycomb-structured magnesium （Mg） scaffolds with interconnected pores of accurately controlled pore size and porosity were fabricated by laser perforation technique. Biodegradable and bioactiveβ- tricalcium phosphate （β-TCP） coatings were prepared on and the biodegradation mechanism was simply evaluated the porous Mg to further improve its biocompatibility, in vitro. It was found that the mechanical properties of this type of porous Mg significantly depended on its porosity. Elastic modulus and compressive strength similar to human bones could be obtained for the porous Mg with porosity of 42.6%-51%. It was observed that the human osteosarcoma cells （UMR106） were well adhered and proliferated on the surface of the β- TCP coated porous Mg, which indicates that theβ-TCP coated porous Mg is promising to be a bone tissue engineering scaffold material.

Biologically Inspired Self-assembling Synthesis of Bone-like Nano-hydroxyapatite/PLGA-(PEG-ASP)_n Composite: A New Biomimetic Bone Tissue Engineering Scaffold Material

A new biomimetic bone tissue engineering scaffold material, nano-HAI PLGA-（ PEG-Asp ）n composite, was synthesized by a biologically inspired self-assembling approach. A novel biodegradable PLGA- （ PEG-Asp ）n copolymer with pendant amine functional groups and enhanced hydrophilicity woo synthesized by bulk ring-opening copolymerization by DL-lactide（ DLLA） and glycolide（ GA ） with Aspartic acid （ Asp ）-Polyethylene glycol（PEG） alt-prepolymer. A Three-dimensional, porous scaffold of the PLGA-（ PEG- Asp）n copolymer was fabricated by a solvent casting , particulate leaching process. The scaffold woo then incubated in modified simulated body fluid （naSBF）. Growth of HA nanocrystals on the inner pore surfaces of the porous scaffold is confirmed by calcium ion binding analyses, SEM , mass increooe meoourements and quantification of phosphate content within scaffolds. SEM analysis demonstrated the nucleation and growth of a continuous bonelike, low crystalline carbonated HA nanocrystals on the inner pore surfaces of the PLGA- （ PEG-Asp ）n scaffolds. The amount of calcium binding, total mass and the mass of phosphate on experimental PLGA- （ PEG-Asp ） n scaffolds at different incubation times in mSBF was significantly greater than that of control PLGA scaffolds. This nano-HA/ PLGA-（ PEG- Asp ）n composite stunts some features of natural bone both in main composition and hierarchical microstrueture. The Asp- PEG alt-prepolymer modified PleA copolymer provide a controllable high surface density and distribution of anionic functional groups which would enhance nucleation and growth of bonelike mineral following exposure to mSBF. This biomimetic treatment provides a simple method for surface functionalization and sabsequent mineral nucleation and self-oosembling on bodegradable polymer scaffolds for tissue engineering.

Experimental Study on Allogenic Decalcified Bone Matrix as Carrier for Bone Tissue Engineering

The biocompatibility and osteogenic activity of allogenic decalcified bone matrix (DBM) used as a carrier for bone tissue engineering were studied. Following the method described by Urist, allogenic DBM was made. In vitro, DBM and bone marrow stromal cell (BMSC) from rabbits were co-cultured for 3-7 days and subjected to HE staining, and a series of histomorphological observations were performed under phase-contrast microscopy and scanning electron microscopy (SEM). In vivo the mixture of DBM/BMSC co-cultured for 3 days was planted into one side of muscules sacrospinalis of rabbits, and the DBM without BMSC was planted into other side as control. Specimens were collected at postoperative week 1, 2 and 4, and subjected to HE staining, and observed under SEM. The results showed during culture in vitro, the BMSCs adherent to the wall of DBM grew, proliferated and had secretive activity. The in vivo experiment revealed that BMSCs and undifferentiated mesenchymal cells in the perivascular region invaded gradually and proliferated together in DBM/BMSC group, and colony-forming units of chondrocytes were found. Osteoblasts, trabecular bone and medullary cavity appeared. The inflammatory reaction around muscles almost disappeared at the second weeks. In pure DBM group, the similar changes appeared from the surface of the DBM to center, and the volume of total regenerate bones was less than the DBM/BMSC group at the same time. The results indicated that the mixture of DBM and BMSC had good biocompatibility and ectopic induced osteogenic activity.

Bone tissue engineering via nanostructured calcium phosphate biomaterials and stem cells

Tissue engineering is promising to meet the increasing need for bone regeneration. Nanostructured calcium phosphate （CAP） biomaterials/scaffolds are of special interest as they share chemical/crystallographic similarities to inorganic components of bone. Three applications of nano-CaP are discussed in this review： nanostructured calcium phosphate cement （CPC）; nano-CaP composites; and nano-CaP coatings. The interactions between stem cells and nano-CaP are highlighted, including cell attachment, orientation/ morphology, differentiation and in vivo bone regeneration. Several trends can be seen： （i） nano-CaP biomaterials support stem cell attachment/proliferation and induce osteogenic differentiation, in some cases even without osteogenic supplements; （ii） the influence of nano-CaP surface patterns on cell alignment is not prominent due to non-uniform distribution of nano-crystals; （iii） nano-CaP can achieve better bone regeneration than conventional CaP biomaterials; （iv） combining stem cells with nano-CaP accelerates bone regeneration, the effect of which can be further enhanced by growth factors; and （v） cell microencapsulation in nano-CaP scaffolds is promising for bone tissue engineering. These understandings would help researchers to further uncover the underlying mechanisms and interactions in nano-CaP stem cell constructs in vitro and in vivo, tailor nano-CaP composite construct design and stem cell type selection to enhance cell function and bone regeneration, and translate laboratory findings to clinical treatments.

Exploring the interconnectivity of biomimetic hierarchical porous Mg scaffolds for bone tissue engineering:Effects of pore size distribution on mechanical properties,degradation behavior and cell migration ability

Interconnectivity is the key characteristic of bone tissue engineering scaffold modulating cell migration,blood vessels invasion and transport of nutrient and waste.However,efforts and understanding of the interconnectivity of porous Mg is limited due to the diverse architectures of pore struts and pore size distribution of Mg scaffold systems.In this work,biomimetic hierarchical porous Mg scaffolds with tailored interconnectivity as well as pore size distribution were prepared by template replication of infiltration casting.Mg scaffold with better interconnectivity showed lower mechanical strength.Enlarging interconnected pores would enhance the interconnectivity of the whole scaffold and reduce the change of ion concentration,pH value and osmolality of the degradation microenvironment due to the lower specific surface area.Nevertheless,the degradation rates of five tested Mg scaffolds were no different because of the same geometry of strut unit.Direct cell culture and evaluation of cell density at both sides of four typical Mg scaffolds indicated that cell migration through hierarchical porous Mg scaffolds could be enhanced by not only bigger interconnected pore size but also larger main pore size.In summary,design of interconnectivity in terms of pore size distribution could regulate mechanical strength,microenvironment in cell culture condition and cell migration potential,and beyond that it shows great potential for personalized therapy which could facilitate the regeneration process.

Vitamin D receptor expression in human bone tissue and dose-dependent activation in resorbing osteoclasts

The effects of vitamin D on osteoblast mineralization are well documented. Reports of the effects of vitamin D on osteoclasts, however, are conflicting, showing both inhibition and stimulation. Finding that resorbing osteoclasts in human bone express vitamin D receptor （VDR）, we examined their response to different concentrations of 25-hydroxy vitamin D3 [25（OH）D3] （100 or 500 nmol·L^-1） and 1,25-dihydroxy vitamin D3 [1,25（OH）2D3] （0.1 or 0.5 nmol·L^-1） metabolites in cell cultures. Specifically, CD14＋ monocytes were cultured in charcoal-stripped serum in the presence of receptor activator of nuclear factor kappa-B ligand （RANKL） and macrophage colony-stimulating factor （M-CSF）. Tartrate-resistant acid phosphatase （TRAP） histochemical staining assays and dentine resorption analysis were used to identify the size and number of osteoclast cells, number of nuclei per cell and resorption activity. The expression of VDR was detected in human bone tissue （ex vivo） by immunohistochemistry and in vitro cell cultures by western blotting. Quantitative reverse transcription-PCR （qRT-PCR） was used to determine the level of expression of vitamin D-related genes in response to vitamin D metabolites. VDR-related genes during osteoclastogenesis, shown by qRT-PCR, was stimulated in response to 500 nmol·L^-1 of 25（OH）D3 and 0.1-0.5 nmol·L^-1 of 1,25（OH）2D3, upregulating cytochrome P450 family 27 subfamily B member I （CYP27B1） and cytochrome P450 family 24 subfamily A member I （CYP24A1）. Osteoclast fusion transcripts transmembrane 7 subfamily member 4 （tm7sf4） and nuclear factor of activated T-cell cytoplasmic 1 （nfatcl） where downregulated in response to vitamin D metabolites. Osteoclast number and resorption activity were also increased. Both 25（OH）D3 and 1,25（OH）2D3 reduced osteoclast size and number when co-treated with RANKL and M-CSF. The evidence for VDR expression in resorbing osteoclasts in vivo and low-dose effects of 1,25（OH）2D3 on osteoclasts in vitro may therefore provide insight into the effects of clinical vitamin D treatments, further providing a counterpoint to the high-dose effects reported from in vitro experiments.

Mechanical Stimulus Inhibits the Growth of a Bone Tissue Model Cultured In Vitro

Objectives To construct the cancellous bone explant model and a method of culturing these bone tissues in vitro, and to investigate the effect of mechanical load on growth of cancellous bone tissue in vtro. Methods Cancellous bone were extracted from rabbit femoral head and cut into I-ram-thick and 8-ram-diameter slices under sterile conditions. HE staining and scanning electron microscopy were employed to identify the histomorphology of the model after being cultured with a new dynamic load and circulating perfusion bioreactor system for 0, 3, 5, and 7 days, respectively. We built a three-dimensional model using microCT and analyzed the loading effects using finite element analysis. The model was subjected to mechanical load of 1000, 2000, 3000, and 4000 με respectively for 30 minutes per day. After 5 days of continuous stimuli, the activities of alkaline phosphatase （AKP） and tartrate-resistant acid phosphatase （TRAP） were detected. Apoptosis was analyzed by DNA ladder detection and caspase-3/8/9 activity detection. Results After being cultured for 3, 5, and 7 days, the bone explant model grew well. HE staining showed the apparent nucleus in cells at the each indicated time, and electron microscope revealed the living cells in the bone tissue. The activities of AKP and TRAP in the bone explant model under mechanical load of 3000 and 4000 με were significantly lower than those in the unstressed bone tissues （all P〈0.05）. DNA ladders were seen in the bone tissue under 3000 and 4000με mechanical load. Moreover, there was significant enhancement in the activities of caspase-3/8/9 in the mechanical stress group of 3000 and 4000 με （all P〈0.05）. Conclusions The cancellous bone explant model extracted from the rabbit femoral head could be alive at least for 7 days in the dynamic load and circulating perfusion bioreactor system, however, pathological mechanical load could affect the bone tissue growth by apoptosis in vitro. The differentiation of osteobiasts and osteoclasts might be inhibited after the model is stimulated by mechanical load of 3000 and 4000 με.

Reduced graphene oxide-grafted bovine serum albumin/bredigite nanocomposites with high mechanical properties and excellent osteogenic bioactivity for bone tissue engineering

The optimization of the scaffolds to provide a suitable matrix and accelerate the regeneration process is vital for bone tissue engineering.However,poor mechanical and biological characteristics remain the primary challenges that must be addressed.For example,although bredigite(Br)has shown great potential for application in bone tissue engineering,it easily fails in replacement.In the present work,these challenges are addressed by reinforcing the Br matrix with nanosheets of graphene oxide(rGO)that have been reduced by bovine serum albumin(BSA)in order to enhance the mechanical properties and biological behavior.The reduction of graphene oxide by BSA improves the water stability of the nanosheets and provides an electrostatic interaction between theBSA-rGO nanosheets and theBr particles.The high thermal conductivity of theBSA-rGO nanosheets decreases the porosity of the Br by transferring heat to the core of the tablet.Furthermore,the addition of BSA-rGO nanosheets into the Br matrix enhances the adhesion of G-292 cells on the surface of the tablets.These findings suggest that the tablet consisting of BSA-rGO-reinforced Br has encouraging potential for application in bone tissue engineering.

3D Nanocomposite Hydrogel Scaffolds Fabricated by Rapid Prototyping for Bone Tissue Engineering

Colloidal gels made of oppositely charged nanoparticles are a novel class of hydrogels and can exhibit pseudoplastic behavior which will enable them to mold easily into specific shapes.These moldable gels can be used as building blocks to self-assemble into integral scaffolds from bottom to up through electrostatic forces.However,they are too weak to maintain scaffold morphology just depending on interparticle interactions such as Van der Waals attraction and electrostatic forces especially for bone tissue engineering.In this study,oppositely charged gelatin nanoparticles were firstly prepared by two-step desolvation method,followed by the mixture with water to form colloid gels.To solve the problem of weak mechanical performance of colloid gels, gelatin macromolecules were introduced into the prepared gels to form blend gels.The blend gels can be easily processed into three-dimensional( 3D) porous scaffolds via motor assisted microsyringe( MAM)system,a nozzle-based rapid prototyping technology,under mild conditions.After fabrication the scaffolds were crosslinked by glutaraldehyde( GA,25% solution in water by weight),then the crosslinked gelatin macromolecules network could form to improve the mechanical properties of colloid gels.The average particle size and zeta potential of gelatin nanoparticles were measured by NanoZS instrument.The morphology and microstructures of scaffolds were characterized by macroscopic images.The mechanical properties of the scaffolds were studied by a universal material testing machine.

Oxysterols as promising small molecules for bone tissue engineering: Systematic review

BACKGROUND Bone tissue engineering is an area of continued interest within orthopaedic surgery,as it promises to create implantable bone substitute materials that obviate the need for autologous bone graft.Recently,oxysterols–oxygenated derivatives of cholesterol-have been proposed as a novel class of osteoinductive small molecules for bone tissue engineering.Here,we present the first systematic review of the in vivo evidence describing the potential therapeutic utility of oxysterols for bone tissue engineering.AIM To systematically review the available literature examining the effect of oxysterols on in vivo bone formation.METHODS We conducted a systematic review of the literature following PRISMA guidelines.Using the PubMed/MEDLINE,Embase,and Web of Science databases,we queried all publications in the English-language literature investigating the effect of oxysterols on in vivo bone formation.Articles were screened for eligibility using PICOS criteria and assessed for potential bias using an expanded version of the SYRCLE Risk of Bias assessment tool.All full-text articles examining the effect of oxysterols on in vivo bone formation were included.Extracted data included:Animal species,surgical/defect model,description of therapeutic and control treatments,and method for assessing bone growth.Primary outcome was fusion rate for spinal fusion models and percent bone regeneration for critical-sized defect models.Data were tabulated and described by both surgical/defect model and oxysterol employed.Additionally,data from all included studies were aggregated to posit the mechanism by which oxysterols may mediate in vivo bone formation.RESULTS Our search identified 267 unique articles,of which 27 underwent full-text review.Thirteen studies(all preclinical)met our inclusion/exclusion criteria.Of the 13 included studies,5 employed spinal fusion models,2 employed critical-sized alveolar defect models,and 6 employed critical-sized calvarial defect models.Based upon SYRCLE criteria,the included studies were found to possess an overall“unclear risk of bias”;54%of studies reported treatment randomization and 38%reported blinding at any level.Overall,seven unique oxysterols were evaluated:20(S)-hydroxycholesterol,22(R)-hydroxycholesterol,22(S)-hydroxycholesterol,Oxy4/Oxy34,Oxy18,Oxy21/Oxy133,and Oxy49.All had statistically significant in vivo osteoinductive properties,with Oxy4/Oxy34,Oxy21/Oxy133,and Oxy49 showing a dose-dependent effect in some cases.In the eight studies that directly compared oxysterols to rhBMP-2-treated animals,similar rates of bone growth occurred in the two groups.Biochemical investigation of these effects suggests that they may be primarily mediated by direct activation of Smoothened in the Hedgehog signaling pathway.CONCLUSION Present preclinical evidence suggests oxysterols significantly augment in vivo bone formation.However,clinical trials are necessary to determine which have the greatest therapeutic potential for orthopaedic surgery patients.

3D Printed Scaffolds as a New Perspective for Bone Tissue Regeneration: Literature Review

Due to the high incidence of bone fractures in the population, it became necessary to produce scaffolds that are able to assist in tissue regeneration. It is necessary to find an appropriate balance between the mechanical and biological properties, in order to mimic the natural tissue, these properties are directly related to the architecture and their degree of porosity, as well as the size of their pores and their interconnectivity. In this perspective, the 3D printing stands out, where the structure is obtained layer by layer, according to a predetermined computational model which provides a greater control of architecture and scaffold geometry and overcomes, in this way, the limitations of traditional techniques of scaffolds manufacturing. In this way, the objective of this seminar is to present the state of the art of the polymer scaffolds produced by 3D printing and applied to bone tissue regeneration, highlighting the advantages and limitations of this process.

Design and Preparation of Bone Tissue Engineering Scaffolds with Porous Controllable Structure

A novel method of designing and preparing bone tissue engineering scaffolds with controllable porous structure of both macro channels and micro pores was proposed. The CAD software UG NX3.0 was used to design the macro channels＇ shape, size and distribution. By integrating rapid prototyping and traditional porogen technique, the macro channels and micro pores were formed respectively. The size, shape and quantity of micro pores were controlled by porogen particulates. The sintered β-TCP porous scaffolds possessed connective macro channels of approximately 500 μm and micro pores of 200-400 μm. The porosity and connectivity of micro pores became higher with the increase of porogen ratio, while the mechanical properties weakened. The average porosity and compressive strength offl-TCP scaffolds prepared with porogen ratio of 60wt% were 78.12% and 0.2983 MPa, respectively. The cells＇ adhesion ratio of scaffolds was 67.43%. The ALP activity, OCN content and cells micro morphology indicated that cells grew and proliferated well on the scaffolds.

Morphological Evaluation of PLA/Soybean Oil Epoxidized Acrylate Three-Dimensional Scaffold in Bone Tissue Engineering

Tissue engineering’s main goal is to regenerate or replace tissues or organs that have been destroyed by disease,injury,or congenital disabilities.Tissue engineering now uses artificial supporting structures called scaffolds to restore damaged tissues and organs.These are utilized to attach the right cells and then grow them.Rapid prototyping appears to be the most promising technology due to its high level of precision and control.Bone tissue replacement“scaffolding”is a common theme discussed in this article.The fused deposition technique was used to construct our scaffold,and a polymer called polylactic acids and soybean oil resin were used to construct our samples.The samples were then divided into two groups;the first group was left without immersion in the simulated body fluid and served as a control for comparison.The second group was immersed in the simulated body fluid.The results of the Field Emission Scanning Electron Microscope(FESEM),Energy Dispersive X-ray Spectroscopy(EDX)and X-ray diffraction(XRD)were utilized to interpret the surface attachment to ions,elements,and compounds,giving us a new perspective on scaffold architecture.In this study,an innovative method has been used to print therapeutic scaffold that combines fused deposition three-dimensional printing with ultraviolet curing to create a high-quality biodegradable polymeric scaffold.Finally,the results demonstrate that adding soybean oil resin to the PLA increased ion attachment to the surface while also attracting tricalcium phosphate formation on the surface of the scaffold,which is highly promising in bone tissue replacement.In conclusion,the soybean oil resin,which is new in the field of bone tissue engineering,shows magnificent characteristics and is a good replacement biopolymer that replaces many ceramic and polymeric materials used in this field that have poor morphological characteristics.

Wnt3a-induced ST2 decellularized matrix ornamented PCL scaffold for bone tissue engineering

The limited bioactivity of scaffold materials is an important factor that restricts the development of bone tissue engineering.Wnt3a activates the classicWnt/β-catenin signaling pathway which effects bone growth and development by the accumulation ofβ-catenin in the nucleus.In this study,we fabricated 3D printed PCL scaffold with Wnt3a-induced murine bone marrow-derived stromal cell line ST2 decellularized matrix(Wnt3a-ST2-dCM-PCL)and ST2 decellularized matrix(ST2-dCM-PCL)by freeze-thaw cycle and DNase decellularization treatment which efficiently decellularized>90%DNA while preserved most protein.Compared to ST2-dCM-PCL,Wnt3a-ST2-dCM-PCL significantly enhanced newly-seeded ST2 proliferation,osteogenic differentiation and upregulated osteogenic marker genes alkaline phosphatase(Alp),Runx2,type I collagen(Col 1)and osteocalcin(Ocn)mRNA expression.After 14 days of osteogenic induction,Wnt3a-ST2-dCM-PCL promoted ST2 mineralization.These results demonstrated that Wnt3a-induced ST2 decellularized matrix improve scaffold materials’osteoinductivity and osteoconductivity.