Scaffolds For Bone Reconstruction Research Articles

Effects of biopolymer functionalization and nanohydroxyapatite heat treatment on the tensile and thermomechanical properties of Bone-Inspired 3D printable nanocomposite biomaterials

Bone-inspired biopolymer nanocomposite grafts are an alternative to conventional bone substitutes if designed to offer a structure with adequate mechanical properties and biocompatibility. In this study, a set of novel 3D printable bone-inspired nanocomposite biomaterials was developed to investigate the effects of additional cross-linking of the biopolymer matrix and heat treatment of nHA particles on the tensile and thermo-mechanical properties of these nanocomposites used in extrusion-based 3D printing. We observed that additional functionalization of acrylated epoxidized soybean oil (AESO), as the main component of the biopolymer matrix, with additional methacrylate groups (mAESO), increased the strength and elastic modulus of extruded nanocomposites by more than three times, as well as doubled the glass transition temperature due to an increased degree of crosslinking in the functionalized matrices. The mAESO-based nanocomposite filaments demonstrated a strength safety factor of 1.5 against the minimum required standard mechanical properties for bone cement according to ISO standard5833. While heat treatment of nHA reduced the frequency of larger agglomerations, no significant difference in mechanical properties was observed. These novel 3D printable nanocomposite biomaterials with their improved strength, modulus and thermo-mechanical properties could be suitable candidates for fabricating complex ‘by design’ 3D printed grafts and scaffolds for bone reconstruction.

Tissue engineering using scaffolds for bone reconstruction: a review of sol-gel silica materials for bone morphogenetic proteins (BMP) encapsulation and release

Tissue engineering using scaffolds for bone reconstruction: a review of sol-gel silica materials for bone morphogenetic proteins (BMP) encapsulation and release

Biocompatibility and Physico-Chemical Properties of Highly Porous PLA/HA Scaffolds for Bone Reconstruction.

The major problem in bone tissue engineering is the development of scaffolds which can simultaneously meet the requirements of porous structure, as well as have the ability to guide the regeneration of damaged tissue by biological fixation. Composites containing biodegradable matrix and bioactive filler are the new hope in this research field. Herein we employed a simple and facile solvent casting particulate-leaching method for producing polylactide acid/hydroxyapatite (PLA/HA) composites at room temperature. FT-IR analysis confirmed the existence of necessary functional groups associated with the PLA/HA composite, whereas energy-dispersive X-ray (EDX) spectra indicated the uniform distribution of hydroxyapatite particles in the polymer matrix. The beehive-like surface morphology of the composites revealed the presence of macropores, ranged from 300 to 400 μm, whereas the thickness of the pores was noticed to be 1–2 μm. The total porosity of the scaffolds, calculated by hydrostatic weighing, was found to be 79%. The water contact angle of pure PLA was decreased from 83.6 ± 1.91° to 62.4 ± 4.17° due to the addition of hydroxyapatite in the polymer matrix. Thus, the wettability of the polymeric biomaterial could be increased by preparing their composites with hydroxyapatite. The adhesion of multipotent mesenchymal stromal cells over the surface of PLA/HA scaffolds was 3.2 times (p = 0.03) higher than the pure PLA sample. Subcutaneous implantation in mice demonstrated a good tolerance of all tested porous scaffolds and widespread ingrowth of tissue into the implant pores. HA-containing scaffolds showed a less pronounced inflammatory response after two weeks of implantation compared to pure PLA. These observations suggest that PLA/HA composites have enormous potential for hard tissue engineering and restoring maxillofacial defects.

Recent Trends and Future Outlooks in the Field of Clay‐Containing Polymer Nanocomposites

Clays are the oldest and potentially one of the most interesting and versatile nanofillers. The blending of surface‐functionalized clay platelets with a polymer matrix can yield a new class of hybrid materials, commonly known as clay‐containing polymer nanocomposites (PCNs), where 1–5% (in general) clay particles by volume are molecularly dispersed within the polymer matrix. The dispersed clay platelets, with their large aspect ratios and low percolation thresholds, can significantly improve the properties of the polymer matrix relative to those of a neat polymer matrix and can introduce new value‐added properties. Over the last few years, researchers have made extraordinary progress in the practical processing and development of various products from different PCNs. The variation of the polymer matrix with different clay surface functionalities can lead to PCNs suited for a wide range of applications, including automobiles, construction materials, packaging, tissue regeneration, load‐bearing scaffolds for bone reconstruction, and many more. This article focuses on recent research efforts in processing and characterization techniques, properties, and applications, and key research challenges and future outlook in the development of multifunctional PCNs. image

Porous zirconia/hydroxyapatite scaffolds for bone reconstruction

ObjectiveHighly porous apatite-based bioceramic scaffolds have been widely investigated as three-dimensional (3D) templates for cell adhesion, proliferation, and differentiation promoting the bone regeneration. Their fragility, however, limits their clinical application especially for a large bone defect. MethodsTo address the hypothesis that using a ZrO2/hydroxyapatite (HAp) composite might improve both the mechanical properties and cellular compatibility of the porous material, we fabricated ZrO2/HAp composite scaffolds with different ZrO2/HAp ratios, and evaluated their characteristics. In addition, porous ZrO2/HAp scaffolds containing bone marrow derived stromal cells (BMSCs) were implanted into critical-size bone defects for 6 weeks in order to evaluate the bone tissue reconstruction with this material. ResultsThe porosity of a ZrO2/HAp scaffold can be adjusted from 72% to 91%, and the compressive strength of the scaffold increased from 2.5 to 13.8MPa when the ZrO2 content increased from 50 to 100wt%. The cell adhesion and proliferation in the ZrO2/HAp scaffold was greatly improved when compared to the scaffold made with ZrO2 alone. Moreover, in vivo study showed that a BMSCs-loaded ZrO2/HAp scaffold provided a suitable 3D environment for BMSC survival and enhanced bone regeneration around the implanted material. SignificanceWe thus showed that a porous ZrO2/HAp composite scaffold has excellent mechanical properties, and cellular/tissue compatibility, and would be a promising substrate to achieve both bone reconstruction and regeneration needed in the treatment of large bone defects.

Novel Porous Composite Polymeric/Ceramic Scaffolds For Bone Reconstruction

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