Pore functionally graded Ti6Al4V scaffolds for bone tissue engineering application

Wang, Su; Liu, Linlin; Li, Kai; Zhu, Luchuang; Chen, Jian; Hao, Yongqiang

doi:10.1016/j.matdes.2019.107643

Cited by 134 publications

(76 citation statements)

References 41 publications

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“…Statistically significant differences between mean Ocn intensity scores for the treatment groups when compared to the other groups were determined byby ANOVA (Significant: * p < 0.0001,^p = 0.004, ■ p < 0.0001, ♦ p = 0.006, ▼p < 0.0001, • p = 0.002) waste products from the larger pores of the construct [43]. But the offset and 250 μm scaffolds with narrower pore sizes were more prone to blockage with soft tissue as the limitation of oxygen and nutrients diffusion that leading to inhibition of bone cell migration and bone growth [44]. In grad 250.top scaffolds that has the smaller pore size (250 μm) on the outside region of scaffold, i.e.…”

Section: Discussionmentioning

confidence: 99%

“…In the micro-CT and histologic evaluations, more bone growth and penetration into the pores was attributed to the higher permeability of the gradient and 500 μm scaffolds which is able to increase the delivery of nutrients and O 2 as well as removing waste products from the larger pores of the construct [ 43 ]. But the offset and 250 μm scaffolds with narrower pore sizes were more prone to blockage with soft tissue as the limitation of oxygen and nutrients diffusion that leading to inhibition of bone cell migration and bone growth [ 44 ]. In grad 250.top scaffolds that has the smaller pore size (250 μm) on the outside region of scaffold, i.e.…”

Section: Discussionmentioning

confidence: 99%

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In vivo bone regeneration assessment of offset and gradient melt electrowritten (MEW) PCL scaffolds

et al. 2020

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Background Biomaterial-based bone tissue engineering represents a promising solution to overcome reduced residual bone volume. It has been previously demonstrated that gradient and offset architectures of three-dimensional melt electrowritten poly-caprolactone (PCL) scaffolds could successfully direct osteoblast cells differentiation toward an osteogenic lineage, resulting in mineralization. The aim of this study was therefore to evaluate the in vivo osteoconductive capacity of PCL scaffolds with these different architectures. Methods Five different calcium phosphate (CaP) coated melt electrowritten PCL pore sized scaffolds: 250 μm and 500 μm, 500 μm with 50% fibre offset (offset.50.50), tri layer gradient 250–500-750 μm (grad.250top) and 750–500-250 μm (grad.750top) were implanted into rodent critical-sized calvarial defects. Empty defects were used as a control. After 4 and 8 weeks of healing, the new bone was assessed by micro-computed tomography and immunohistochemistry. Results Significantly more newly formed bone was shown in the grad.250top scaffold 8 weeks post-implantation. Histological investigation also showed that soft tissue was replaced with newly formed bone and fully covered the grad.250top scaffold. While, the bone healing did not happen completely in the 250 μm, offset.50.50 scaffolds and blank calvaria defects following 8 weeks of implantation. Immunohistochemical analysis showed the expression of osteogenic markers was present in all scaffold groups at both time points. The mineralization marker Osteocalcin was detected with the highest intensity in the grad.250top and 500 μm scaffolds. Moreover, the expression of the endothelial markers showed that robust angiogenesis was involved in the repair process. Conclusions These results suggest that the gradient pore size structure provides superior conditions for bone regeneration.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

In vivo bone regeneration assessment of offset and gradient melt electrowritten (MEW) PCL scaffolds

et al. 2020

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“…Furthermore, higher pore size in gradient scaffolds has been shown to enhance permeability, cell migration, as well as sufficient nutrients and oxygen tension in larger pores and up-regulate osteopontin and collagen type I expression, thus generating more bone mass, vascularization and blood vessel ingrowth while inhibiting the formation of cartilaginous tissue in the regenerating sites [16,17]. On the other hand, the smaller size of gradient pores promote cell seeding and growth by providing higher surface area [18].…”

Section: Introductionmentioning

confidence: 99%

Role of offset and gradient architectures of 3-D melt electrowritten scaffold on differentiation and mineralization of osteoblasts

et al. 2020

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Background: Cell-scaffold based therapies have the potential to offer an efficient osseous regenerative treatment and PCL has been commonly used as a scaffold, however its effectiveness is limited by poor cellular retention properties. This may be improved through a porous scaffold structure with efficient pore arrangement to increase cell entrapment. To facilitate this, melt electrowriting (MEW) has been developed as a technique able to fabricate cell-supporting scaffolds with precise micro pore sizes via predictable fibre deposition. The effect of the scaffold's architecture on cellular gene expression however has not been fully elucidated. Methods: The design and fabrication of three different uniform pore structures (250, 500 and 750 μm), as well as two offset scaffolds with different layout of fibres (30 and 50%) and one complex scaffold with three gradient pore sizes of 250-500-750 μm, was performed by using MEW. Calcium phosphate modification was applied to enhance the PCL scaffold hydrophilicity and bone inductivity prior to seeding with osteoblasts which were then maintained in culture for up to 30 days. Over this time, osteoblast cell morphology, matrix mineralisation, osteogenic gene expression and collagen production were assessed. Results: The in vitro findings revealed that the gradient scaffold significantly increased alkaline phosphatase activity in the attached osteoblasts while matrix mineralization was higher in the 50% offset scaffolds. The expression of osteocalcin and osteopontin genes were also upregulated compared to other osteogenic genes following 30 days culture, particularly in offset and gradient scaffold structures. Immunostaining showed significant expression of osteocalcin in offset and gradient scaffold structures. Conclusions: This study demonstrated that the heterogenous pore sizes in gradient and fibre offset PCL scaffolds prepared using MEW significantly improved the osteogenic potential of osteoblasts and hence may provide superior outcomes in bone regeneration applications.

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“…Therefore, novel solutions and biomaterials are being developed to support tissue regeneration. To date, numerous scaffolds based on ceramics (e.g., titanium dioxide [ 3 , 4 ]), metals [ 5 ], or natural and synthetic polymers [ 6 , 7 ]) have been developed and evaluated in terms of their biocompatibility and bioactivity.…”

Section: Introductionmentioning

confidence: 99%

Surface-Modified Poly(l-lactide-co-glycolide) Scaffolds for the Treatment of Osteochondral Critical Size Defects—In Vivo Studies on Rabbits

Krok-Borkowicz

Reczyńska

Rumian

et al. 2020

IJMS

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Poly(l-lactide-co-glycolide) (PLGA) porous scaffolds were modified with collagen type I (PLGA/coll) or hydroxyapatite (PLGA/HAp) and implanted in rabbits osteochondral defects to check their biocompatibility and bone tissue regeneration potential. The scaffolds were fabricated using solvent casting/particulate leaching method. Their total porosity was 85% and the pore size was in the range of 250–320 µm. The physico-chemical properties of the scaffolds were evaluated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffractometry (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), sessile drop, and compression tests. Three types of the scaffolds (unmodified PLGA, PLGA/coll, and PLGA/HAp) were implanted into the defects created in New Zealand rabbit femoral trochlears; empty defect acted as control. Samples were extracted after 1, 4, 12, and 26 weeks from the implantation, evaluated using micro-computed tomography (µCT), and stained by Masson–Goldner and hematoxylin-eosin. The results showed that the proposed method is suitable for fabrication of highly porous PLGA scaffolds. Effective deposition of both coll and HAp was confirmed on all surfaces of the pores through the entire scaffold volume. In the in vivo model, PLGA and PLGA/HAp scaffolds enhanced tissue ingrowth as shown by histological and morphometric analyses. Bone formation was the highest for PLGA/HAp scaffolds as evidenced by µCT. Neo-tissue formation in the defect site was well correlated with degradation kinetics of the scaffold material. Interestingly, around PLGA/coll extensive inflammation and inhibited tissue healing were detected, presumably due to immunological response of the host towards collagen of bovine origin. To summarize, PLGA scaffolds modified with HAp are the most promising materials for bone tissue regeneration.

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Pore functionally graded Ti6Al4V scaffolds for bone tissue engineering application

Cited by 134 publications

References 41 publications

In vivo bone regeneration assessment of offset and gradient melt electrowritten (MEW) PCL scaffolds

In vivo bone regeneration assessment of offset and gradient melt electrowritten (MEW) PCL scaffolds

Role of offset and gradient architectures of 3-D melt electrowritten scaffold on differentiation and mineralization of osteoblasts

Surface-Modified Poly(l-lactide-co-glycolide) Scaffolds for the Treatment of Osteochondral Critical Size Defects—In Vivo Studies on Rabbits

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