Bone tissue is the structural component of the body, which allows locomotion, protects vital internal organs, and provides the maintenance of mineral homeostasis. Several bone-related pathologies ...generate critical-size bone defects that our organism is not able to heal spontaneously and require a therapeutic action. Conventional therapies span from pharmacological to interventional methodologies, all of them characterized by several drawbacks. To circumvent these effects, tissue engineering and regenerative medicine are innovative and promising approaches that exploit the capability of bone progenitors, especially mesenchymal stem cells, to differentiate into functional bone cells. So far, several materials have been tested in order to guarantee the specific requirements for bone tissue regeneration, ranging from the material biocompatibility to the ideal 3D bone-like architectural structure. In this review, we analyse the state-of-the-art of the most widespread polymeric scaffold materials and their application in in vitro and in vivo models, in order to evaluate their usability in the field of bone tissue engineering. Here, we will present several adopted strategies in scaffold production, from the different combination of materials, to chemical factor inclusion, embedding of cells, and manufacturing technology improvement.
Bone tissue engineering using polymer based scaffolds have been studied a lot in last decades. Considering the qualities of all the polymers desired to be used as scaffolds, Polycaprolactone (PCL) ...polyester apart from being biocompatible and biodegradable qualifies to an appreciable level due its easy availability, cost efficacy and suitability for modification. Its adjustable physio-chemical state, biological properties and mechanical strength renders it to withstand physical, chemical and mechanical, insults without significant loss of its properties. This review aims to critically analyse the efficacy of PCL as a biomaterial for bone scaffolds.
Biomaterials that mimic biological tissues are in great demand in tissue engineering. Hydrogels are rising as a conducive candidate in tissue engineering on account of their water-holding capacity, ...mechanical strength, and elasticity. Nevertheless, the development of hydrogels that mimic biological tissues with the desired stability and mechanical strength, remains a notable barrier. In this investigation, chitosan/alginate hydrogels were prepared by tuning the chitosan concentration from 0.5 % to 2.5 %w/v with a fixed 1 %w/v alginate concentration using 0.1 % glutaraldehyde as a gelling agent. The hydrogel system forms through covalent bonding between chitosan and alginate, mediated by aldehyde groups of the glutaraldehyde. The mechanical strength of the hydrogel was elucidated by probing its viscoelastic behavior through rheological analysis. The rheological investigations revealed that the prepared chitosan/alginate hydrogels are profoundly stable with shear-thinning characteristics. The increase in chitosan concentration enhanced the stability and viscoelastic attributes of the hydrogels. The yield stress values ranging from 0.93 kPa to 14.24 kPa indicate the possibility of using these hydrogels in bioadhesives and soft and bone tissue engineering. The complex modulus of the prepared chitosan/alginate hydrogels resembles the shear modulus of liver tissues, osteogenic cells, and articular cartilage, and hence, these hydrogels pose as suitable candidates in liver, bone, and cartilage tissue engineering. The chitosan/alginate hydrogels possess outstanding self-healing ability, along with biocompatibility, stability, and mechanical strength, rendering them highly advantageous for applications in biomedical tissue engineering and bioadhesives.
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Bone tissue engineering (BTE) aims to develop implantable bone replacements for severe skeletal abnormalities that do not heal. In the field of BTE, chitosan (CS) has become a leading polysaccharide ...in the development of bone scaffolds. Although CS has several excellent properties, such as biodegradability, biocompatibility, and antibacterial properties, it has limitations for use in BTE because of its poor mechanical properties, increased degradation, and minimal bioactivity. To address these issues, researchers have explored other biomaterials, such as synthetic polymers, ceramics, and CS coatings on metals, to produce CS-based biocomposite scaffolds for BTE applications. These CS-based biocomposite scaffolds demonstrate superior properties, including mechanical characteristics, such as compressive strength, Young's modulus, and tensile strength. In addition, they are compatible with neighboring tissues, exhibit a controlled rate of degradation, and promote cell adhesion, proliferation, and osteoblast differentiation. This review provides a brief outline of the recent progress in making different CS-based biocomposite scaffolds and how to characterize them so that their mechanical properties can be tuned using crosslinkers for bone regeneration.
This book relates the mechanical and structural properties of bone to its function in man and other vertebrates. John Currey, one of the pioneers of modern bone research, reviews existing information ...in the field and particularly emphasizes the correlation of the structure of bone with its various uses.
Originally published in 1984.
ThePrinceton Legacy Libraryuses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.
Vitamin D3, vitamin K2, and Mg (10%, 1.25%, and 5%, w/w, respectively)-loaded PLA (12%, w/v) (TCP (5%, w/v))/PCL (12%, w/v) 1:1 (v/v) composite nanofibers (DKMF) were produced by electrospinning ...method (ES) and their osteoinductive effects were investigated in cell culture test. Neither pure nanofibers nor DKMF caused a significant cytotoxic effect in fibroblasts. The induction of the stem cell differentiation into osteogenic cells was observed in the cell culture with both DKMF and pure nanofibers, separately. Vitamin D3, vitamin K2, and magnesium demonstrated to support the osteogenic differentiation of mesenchymal stem cells by expressing Runx2, BMP2, and osteopontin and suppressing PPAR-γ and Sox9. Therefore, the Wnt/β-catenin signaling pathway was activated by DKMF. DKMF promoted large axonal sprouting and needle-like elongation of osteoblast cells and enhanced cellular functions such as migration, infiltration, proliferation, and differentiation after seven days of incubation using confocal laser scanning microscopy. The results showed that DKMF demonstrated sustained drug release for 144 h, tougher and stronger structure, higher tensile strength, increased water up-take capacity, decreased degradation ratio, and slightly lower Tm and Tg values compared to pure nanofibers. Consequently, DKMF is a promising treatment approach in bone tissue engineering due to its osteoinductive effects.
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•Vitamin D3, vitamin K2, and Mg were loaded in PLA(TCP)/PCL nanofibers (DKMF).•DKMF supported the osteogenic differentiation of mesenchymal stem cells.•DKMF expressed Runx2, BMP2, and osteopontin and suppressed PPAR-γ and Sox9.•The Wnt/β-Catenin signaling pathway was activated by DKMF.•DKMF promoted large axonal sprouting and needle-like elongation of osteoblast cells.
A review of 3D printed porous ceramics Zhang, Feng; Li, Zongan; Xu, Mengjia ...
Journal of the European Ceramic Society,
July 2022, 2022-07-00, Letnik:
42, Številka:
8
Journal Article
Recenzirano
Three-dimensional (3D) printing of ceramics has gained widespread attentions in recent years. Many excellent reviews have reported the printing of ceramics. However, most of them focus on printing of ...dense ceramics or general ceramic aspects, there is no systematical review about 3D printing of porous ceramics. In this review paper, the 3D printing technologies for fabricating of porous ceramic parts are introduced, including binder jetting, selective laser sintering, direct ink writing, stereolithography, laminated object manufacturing, and indirect 3D printing processes. The techniques to fabricate hierarchical porous ceramics by integrating 3D printing with one or more conventional porous ceramics fabrication approaches are reviewed. The main properties of porous ceramics such as pore size, porosity, and compressive strength are discussed. The emerging applications of 3D printed porous ceramics are presented with a focus on the booming application in bone tissue engineering. Finally, summary and a perspective on the future research directions for 3D printed porous ceramics are provided.
Polylactic acid/Hydroxyapatite (PLA/HA) composite was widely studied and applied in the field of biomaterials for its good processability, bioactivity, and mechanical properties. In addition to ...traditional preparation methods, additive manufacturing has also been adopted to prepare PLA/HA composites with customized geometries. This work combined the comprehensive optimized PLLA (L-polylactic acid)/nano-HA (nHA) composite with the low-cost and stable Fused deposition modeling (FDM) technology to successfully prepare PLLA/nHA porous bone repair scaffolds. The results showed that PLLA/nHA composite ink satisfied the smoothness of printing, and the accuracy also met the requirements of personalized bone repair application. The high loaded nHA scaffold had suitable compressive strength was significantly higher than those of pure HA ceramic scaffold and cancellous bone. Besides, in vitro bone-like apatite formation on the surface in the degradation process and in vivo evaluations further verified its good osteogenic property. Compared with other complex and cutting-edge 3D printing technologies, this study provides a low-cost, stable, simple and fast way to realize personalized printing of bone repair scaffolds, which is undoubtedly conductive to the improvement and rapid deployment of personalized biomaterials in clinical applications.
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•Comprehensive optimized PLLA/nano-hydroxyapatite composite was made successfully for bone repair scaffold printing.•Bone-like apatite can form on the scaffold surface in vitro degradation experiments just in PBS, indicating the high bioactivity of scaffold.•The high loaded nano- hydroxyapatite scaffold has suitable compressive strength and good osteogenic property.•This study provides a low-cost, stable, simple and fast way to realize personalized printing of bone repair scaffolds.
Tissue‐engineered hydrogels have received extensive attention as their mechanical properties, chemical compositions, and biological signals can be dynamically modified for mimicking extracellular ...matrices (ECM). Herein, the synthesis of novel double network (DN) hydrogels with tunable mechanical properties using combinatorial screening methods is reported. Furthermore, nanoengineered (NE) hydrogels are constructed by addition of ultrathin 2D black phosphorus (BP) nanosheets to the DN hydrogels with multiple functions for mimicking the ECM microenvironment to induce tissue regeneration. Notably, it is found that the BP nanosheets exhibit intrinsic properties for induced CaP crystal particle formation and therefore improve the mineralization ability of NE hydrogels. Finally, in vitro and in vivo data demonstrate that the BP nanosheets, mineralized CaP crystal nanoparticles, and excellent mechanical properties provide a favorable ECM microenvironment to mediate greater osteogenic cell differentiation and bone regeneration. Consequently, the combination of bioactive chemical materials and excellent mechanical stimuli of NE hydrogels inspire novel engineering strategies for bone‐tissue regeneration.
Black phosphorus (BP) nanosheets–based hydrogels show excellent mechanical properties, favorable mineralization, and high bioactivity. The ultra‐high strength hydrogels are made of covalent bonds combined with a high density of polymer entanglements and hydrogen bonds. Notably, the BP nanosheets exhibit intrinsic properties for induced calcium phosphate particle formation and therefore improve the mineralization of the hydrogels.
The implantation of bioresorbable compositions has emerged as a promising therapeutic strategy to treat damaged bone tissues. To develop versatile bone scaffolds, polycaprolactone (PCL) is known as a ...dominant polymeric material regarding its unique biocompatibility and biodegradability. However, using PCL in a single structure reveals insufficient mechanical properties, in tandem with poor biological activity. To modulate these features, the combination of PCL and chitosan has been broadly proposed due to the proper bioactivity behavior of the chitosan component. It is also declared that the presence of MXene elements in the bone scaffolds could enhance the osteogenic impact and modify the mechanical behavior to match the surrounding bone tissue. To explore the synergetic effect of chitosan and MXene in enhancing the features of PCL structure, the PCL/chitosan/MXene ternary system was designed in this study. Accordingly, MXene nanosheets were synthesized and incorporated with various filler contents of 1, 3, and 5 % into PCL/chitosan to boost the overall characteristics. The obtained data exhibited a rise in porosity ratio from 22 to 30 % and a decrease in contact angle from 95.45 to 79.86⁰ by embedding MXene up to 3 %. Young's modulus was enhanced from 0.4 to 1.2 MPa, corroborating the generation of scaffolds with superior mechanical strength and rigidity. The compositions containing MXene up to 3 % revealed no cytotoxicity and human osteoblast cell assay approved the cell adhesion affinity of the designed architectures. Furthermore, the presence of MXene nanosheets resulted in the promoting of antimicrobial features in the membranes as a bifunctional behavior. Correspondingly, embedding an optimized ratio of MXene nanoparticles into the PCL/chitosan scaffold could create a suitable scaffolding architecture toward the generation of new bone tissues, benefiting appropriate cell attachment, proliferation, and differentiation.
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•PCL/chitosan bifunctional compositions loaded with MXene (Ti3C2Tx) nanoflakes were developed for bone tissue regeneration.•The addition of Ti3C2Tx filler into the PCL/chitosan caused the formation of tiny pores in a highly porous structure.•Inherent features of Ti3C2Tx and chitosan components enhanced hydrophilicity in the designed tissues.•PCL and Ti3C2Tx provided proper mechanical characteristics in the developed ternary architecture.•Cell adhesion and antimicrobial properties were inclined as a result of MXene presence in the deployed scaffolds.
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