scholarly journals Plasma Spray vs. Electrochemical Deposition: Toward a Better Osteogenic Effect of Hydroxyapatite Coatings on 3D-Printed Titanium Scaffolds

2021 ◽  
Vol 9 ◽  
Author(s):  
Yang Sun ◽  
Xing Zhang ◽  
Mingran Luo ◽  
Weifan Hu ◽  
Li Zheng ◽  
...  
Keyword(s):  
Electrochemical Deposition ◽  
Plasma Spray ◽  
Bone Repair ◽  
Three Dimensional ◽  
Repair Capacity ◽  
Electrochemically Deposited ◽  
3D Printed ◽  
Plasma Sprayed

Surface modification of three-dimensional (3D)-printed titanium (Ti) scaffolds with hydroxyapatite (HA) has been a research hotspot in biomedical engineering. However, unlike HA coatings on a plain surface, 3D-printed Ti scaffolds have inherent porous structures that influence the characteristics of HA coatings and osteointegration. In the present study, HA coatings were successfully fabricated on 3D-printed Ti scaffolds using plasma spray and electrochemical deposition, named plasma sprayed HA (PSHA) and electrochemically deposited HA (EDHA), respectively. Compared to EDHA scaffolds, HA coatings on PSHA scaffolds were smooth and continuous. In vitro cell studies confirmed that PSHA scaffolds have better potential to promote bone mesenchymal stem cell adhesion, proliferation, and osteogenic differentiation than EDHA scaffolds in the early and late stages. Moreover, in vivo studies showed that PSHA scaffolds were endowed with superior bone repair capacity. Although the EDHA technology is simpler and more controllable, its limitation due to the crystalline and HA structures needs to be improved in the future. Thus, we believe that plasma spray is a better choice for fabricating HA coatings on implanted scaffolds, which may become a promising method for treating bone defects.

Three-Dimensional-Printed External Scaffolds Mitigate Loss of Volume and Topography in Engineered Elastic Cartilage Constructs

Cartilage ◽  
2021 ◽  
pp. 194760352110495
Author(s):  
Xue Dong ◽  
Ishani D. Premaratne ◽  
Jaime L. Bernstein ◽  
Arash Samadi ◽  
Alexandra J. Lin ◽  
...  
Keyword(s):  
Injection Molding ◽  
Type I Collagen ◽  
Three Dimensional ◽  
Type I ◽  
Base Area ◽  
Elastic Cartilage ◽  
3D Printed ◽  
Injection Molded

Objective: A major obstacle in the clinical translation of engineered auricular scaffolds is the significant contraction and loss of topography that occur during maturation of the soft collagen-chondrocyte matrix into elastic cartilage. We hypothesized that 3-dimensional-printed, biocompatible scaffolds would “protect” maturing hydrogel constructs from contraction and loss of topography. Design: External disc-shaped and “ridged” scaffolds were designed and 3D-printed using polylactic acid (PLA). Acellular type I collagen constructs were cultured in vitro for up to 3 months. Collagen constructs seeded with bovine auricular chondrocytes (BAuCs) were prepared in 3 groups and implanted subcutaneously in vivo for 3 months: preformed discs with (“Scaffolded/S”) or without (“Naked/N”) an external scaffold and discs that were formed within an external scaffold via injection molding (“Injection Molded/SInj”). Results: The presence of an external scaffold or use of injection molding methodology did not affect the acellular construct volume or base area loss. In vivo, the presence of an external scaffold significantly improved preservation of volume and base area at 3 months compared to the naked group ( P < 0.05). Construct contraction was mitigated even further in the injection molded group, and topography of the ridged constructs was maintained with greater fidelity ( P < 0.05). Histology verified the development of mature auricular cartilage in the constructs within external scaffolds after 3 months. Conclusion: Custom-designed, 3D-printed, biocompatible external scaffolds significantly mitigate BAuC-seeded construct contraction and maintain complex topography. Further refinement and scaling of this approach in conjunction with construct fabrication utilizing injection molding may aid in the development of full-scale auricular scaffolds.

scholarly journals Biocompatibility of Bespoke 3D-Printed Titanium Alloy Plates for Treating Acetabular Fractures

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Xuezhi Lin ◽  
Xingling Xiao ◽  
Yimeng Wang ◽  
Cheng Gu ◽  
Canbin Wang ◽  
...  
Keyword(s):  
Titanium Alloy ◽  
Culture Medium ◽  
Three Dimensional ◽  
Acetabular Fractures ◽  
Three Dimensional Printing ◽  
3D Printed ◽  
Manufacturing Techniques ◽  
Dimensional Printing

Treatment of acetabular fractures is challenging, not only because of its complicated anatomy but also because of the lack of fitting plates. Personalized titanium alloy plates can be fabricated by selective laser melting (SLM) but the biocompatibility of these three-dimensional printing (3D-printed) plates remains unknown. Plates were manufactured by SLM and their cytocompatibility was assessed by observing the metabolism of L929 fibroblasts incubated with culture medium extracts using a CCK-8 assay and their morphology by light microscopy. Allergenicity was tested using a guinea pig maximization test. In addition, acute systemic toxicity of the 3D-printed plates was determined by injecting extracts from the implants into the tail veins of mice. Finally, the histocompatibility of the plates was investigated by implanting them into the dorsal muscles of rabbits. The in vitro results suggested that cytocompatibility of the 3D-printed plates was similar to that of conventional plates. The in vivo data also demonstrated histocompatibility that was comparable between the two manufacturing techniques. In conclusion, both in vivo and in vitro experiments suggested favorable biocompatibility of 3D-printed titanium alloy plates, indicating that it is a promising option for treatment of acetabular fractures.

scholarly journals Three-dimensional printed polylactic acid scaffold integrated with BMP-2 laden hydrogel for precise bone regeneration

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Misun Cha ◽  
Yuan-Zhe Jin ◽  
Jin Wook Park ◽  
Kyung Mee Lee ◽  
Shi Huan Han ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Polylactic Acid ◽  
Three Dimensional ◽  
Burst Release ◽  
Defect Model ◽  
Ectopic Ossification ◽  
Significant Difference ◽  
3D Printed

Abstract Background Critical bone defects remain challenges for clinicians, which cannot heal spontaneously and require medical intervention. Following the development of three-dimensional (3D) printing technology is widely used in bone tissue engineering for its outstanding customizability. The 3D printed scaffolds were usually accompanied with growth factors, such as bone morphometric protein 2 (BMP-2), whose effects have been widely investigated on bone regeneration. We previously fabricated and investigated the effect of a polylactic acid (PLA) cage/Biogel scaffold as a carrier of BMP-2. In this study, we furtherly investigated the effect of another shape of PLA cage/Biogel scaffold as a carrier of BMP-2 in a rat calvaria defect model and an ectopic ossification (EO) model. Method The PLA scaffold was printed with a basic commercial 3D printer, and the PLA scaffold was combined with gelatin and alginate-based Biogel and BMP-2 to induce bone regeneration. The experimental groups were divided into PLA scaffold, PLA scaffold with Biogel, PLA scaffold filled with BMP-2, and PLA scaffold with Biogel and BMP-2 and were tested both in vitro and in vivo. One-way ANOVA with Bonferroni post-hoc analysis was used to determine whether statistically significant difference exists between groups. Result The in vitro results showed the cage/Biogel scaffold released BMP-2 with an initial burst release and followed by a sustained slow-release pattern. The released BMP-2 maintained its osteoinductivity for at least 14 days. The in vivo results showed the cage/Biogel/BMP-2 group had the highest bone regeneration in the rat calvarial defect model and EO model. Especially, the bone regenerated more regularly in the EO model at the implanted sites, which indicated the cage/Biogel had an outstanding ability to control the shape of regenerated bone. Conclusion In conclusion, the 3D printed PLA cage/Biogel scaffold system was proved to be a proper carrier for BMP-2 that induced significant bone regeneration and induced bone formation following the designed shape.

scholarly journals Vascularized Bone Regeneration Accelerated by 3D-Printed Nanosilicate-Functionalized Polycaprolactone Scaffold

2021 ◽  
Author(s):  
Xiongcheng Xu ◽  
Long Xiao ◽  
Yanmei Xu ◽  
Jin Zhuo ◽  
Xue Yang ◽  
...  
Keyword(s):  
3D Printing ◽  
Bone Regeneration ◽  
Bone Repair ◽  
Cytokine Secretion ◽  
Printing Technology ◽  
3D Printing Technology ◽  
3D Printed ◽  
Vascularized Bone

Abstract Critical oral-maxillofacial bone defects, damaged by trauma and tumors, not only affect the physiological functions and mental health of patients but are also highly challenging to reconstruct. Personalized biomaterials customized by 3D printing technology have the potential to match oral-maxillofacial bone repair and regeneration requirements. Laponite nanosilicates have been added to biomaterials to achieve biofunctional modification owing to their excellent biocompatibility and bioactivity. Herein, porous nanosilicate-functionalized polycaprolactone (PCL/LAP) was fabricated by 3D printing technology, and its bioactivities in bone regeneration were investigated in vitro and in vivo. In vitro experiments demonstrated that PCL/LAP exhibited good cytocompatibility and enhanced the viability of BMSCs. PCL/LAP functioned to stimulate osteogenic differentiation of BMSCs at the mRNA and protein levels and elevated angiogenic gene expression and cytokine secretion. Moreover, BMSCs cultured on PCL/LAP promoted the angiogenesis potential of endothelial cells by angiogenic cytokine secretion. Then, PCL/LAP scaffolds were implanted into the calvarial defect model. Toxicological safety of PCL/LAP was confirmed, and significant enhancement of vascularized bone formation was observed. Taken together, 3D-printed PCL/LAP scaffolds with brilliant osteogenesis to enhance bone regeneration could be envisaged as an outstanding bone substitute for a promising change in oral-maxillofacial bone defect reconstruction.

scholarly journals 3D Bioprinting of Vascularized Tissues for in vitro and in vivo Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Earnest P. Chen ◽  
Zeren Toksoy ◽  
Bruce A. Davis ◽  
John P. Geibel
Keyword(s):  
Tissue Engineering ◽  
Drug Testing ◽  
Rapid Development ◽  
Three Dimensional ◽  
3D Bioprinting ◽  
Vascular Networks ◽  
Main Challenge ◽  
3D Printed

With a limited supply of organ donors and available organs for transplantation, the aim of tissue engineering with three-dimensional (3D) bioprinting technology is to construct fully functional and viable tissue and organ replacements for various clinical applications. 3D bioprinting allows for the customization of complex tissue architecture with numerous combinations of materials and printing methods to build different tissue types, and eventually fully functional replacement organs. The main challenge of maintaining 3D printed tissue viability is the inclusion of complex vascular networks for nutrient transport and waste disposal. Rapid development and discoveries in recent years have taken huge strides toward perfecting the incorporation of vascular networks in 3D printed tissue and organs. In this review, we will discuss the latest advancements in fabricating vascularized tissue and organs including novel strategies and materials, and their applications. Our discussion will begin with the exploration of printing vasculature, progress through the current statuses of bioprinting tissue/organoids from bone to muscles to organs, and conclude with relevant applications for in vitro models and drug testing. We will also explore and discuss the current limitations of vascularized tissue engineering and some of the promising future directions this technology may bring.

scholarly journals In vivo delivery of VEGF RNA and protein to increase osteogenesis and intraosseous angiogenesis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Robin M. H. Rumney ◽  
Stuart A. Lanham ◽  
Janos M. Kanczler ◽  
Alexander P. Kao ◽  
Lalitha Thiagarajan ◽  
...  
Keyword(s):  
Blood Vessel ◽  
Bone Repair ◽  
Three Dimensional ◽  
Model Systems ◽  
High Dose ◽  
In Ovo ◽  
Calvarial Bone ◽  
Endothelial Growth Factor

AbstractDeficient bone vasculature is a key component in pathological conditions ranging from developmental skeletal abnormalities to impaired bone repair. Vascularisation is dependent upon vascular endothelial growth factor (VEGF), which drives both angiogenesis and osteogenesis. The aim of this study was to examine the efficacy of blood vessel and bone formation following transfection with VEGF RNA or delivery of recombinant human VEGF165 protein (rhVEGF165) across in vitro and in vivo model systems. To quantify blood vessels within bone, an innovative approach was developed using high-resolution X-ray computed tomography (XCT) to generate quantifiable three-dimensional reconstructions. Application of rhVEGF165 enhanced osteogenesis, as evidenced by increased human osteoblast-like MG-63 cell proliferation in vitro and calvarial bone thickness following in vivo administration. In contrast, transfection with VEGF RNA triggered angiogenic effects by promoting VEGF protein secretion from MG-63VEGF165 cells in vitro, which resulted in significantly increased angiogenesis in the chorioallantoic (CAM) assay in ovo. Furthermore, direct transfection of bone with VEGF RNA in vivo increased intraosseous vascular branching. This study demonstrates the importance of continuous supply as opposed to a single high dose of VEGF on angiogenesis and osteogenesis and, illustrates the potential of XCT in delineating in 3D, blood vessel connectivity in bone.

scholarly journals Controlled release of basic fibroblast growth factor from a peptide biomaterial for bone regeneration

2020 ◽  
Vol 7 (4) ◽  
pp. 191830 ◽  
Author(s):  
WeiKang Zhao ◽  
Yuling Li ◽  
Ao Zhou ◽  
Xiaojun Chen ◽  
Kai Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bone Repair ◽  
Three Dimensional ◽  
Controlled Drug Release ◽  
Confocal Laser ◽  
Polyamide 66 ◽  
Bone Mesenchymal Stem Cells ◽  
Alizarin Red

Self-assembled peptide scaffolds based on D-RADA16 are an important matrix for controlled drug release and three-dimensional cell culture. In this work, D-RADA16 peptide hydrogels were coated on artificial bone composed of nano-hydroxyapatite/polyamide 66 (nHA/PA66) to obtain a porous drug-releasing structure for treating bone defects. The developed materials were characterized via transmission electron microscopy and scanning electron microscopy. The proliferation and adhesion of bone mesenchymal stem cells (BMSCs) were examined by confocal laser microscopy and CCK-8 experiments. The osteogenic ability of the porous materials towards bone BMSCs was examined in vitro by staining with Alizarin Red S and alkaline phosphatase, and bioactivity was evaluated in vivo . The results revealed that nHA/PA66/D-RADA16/bFGF reduces the degradation rate of D-RADA16 hydrogels and prolongs sustained release of bFGF, which would promote BMSCs proliferation, adhesion and osteogenesis in vitro and bone repair in vivo . Thus, it deserves more attention and is worthy of further research.

scholarly journals Biomimetic Mineralization on 3d Printed Pla Scaffolds: On the Response of Human Primary Osteoblasts Spheroids and in Vivo Implantation

2020 ◽  
Author(s):  
Marianna O. C. Maia-Pinto ◽  
Ana Carolina B. Brochado ◽  
Bruna Nunes Teixeira ◽  
Suelen C. Sartoretto ◽  
Marcelo J. Uzeda ◽  
...  
Keyword(s):  
Bone Repair ◽  
In Vitro Release ◽  
Biological Response ◽  
Bone Morphogenetic Protein 2 ◽  
Primary Osteoblast ◽  
Rat Calvaria ◽  
3D Printed ◽  
Human Primary Osteoblast

This study aimed to assess the response of 3D printed PLA scaffolds biomimetically coated with apatite on human primary osteoblast spheroids and evaluate the biological response to its association with Bone Morphogenetic Protein 2 (rhBMP-2) in rat calvaria. PLA scaffolds were produced via 3D printing, soaked in simulated body fluid (SBF) solution, and characterized by physical-chemical, morphological, and mechanical properties. The in vitro biological response was assessed with human primary osteoblast (HOb) spheroids. The in vivo analysis was conducted through the implantation of 3D printed PLA scaffolds either alone, covered by apatite (PLA-CaP) or PLA-CaP loaded with rhBMP-2 (PLA-CaP+rhBMP-2) on critical-sized defects (8 mm) of rat calvaria. Increased cell adhesion and in vitro release of growth factors (PDGF, bFGF, VEGF) was observed for PLA-CaP scaffolds when pre-treated with FBS. PLA-CaP+BMP2 presented higher values of newly formed bone (NFB) than other groups at all experimental periods (p&amp;lt;0.05), attaining 44.85% of NFB after 6 months. These findings indicate that functionalization of PLA scaffolds with biomimetic apatite can improve its biological properties in the presence of complex biological media. Its association with BMP2 may enhance bone repair, suggesting this strategy as a promising candidate for bone tissue engineering.

scholarly journals Three-Dimensional-Printed Scaffolds for Meniscus Tissue Engineering: Opportunity for the Future in the Orthopaedic World

2021 ◽  
Vol 12 (4) ◽  
pp. 69
Author(s):  
Angelo V. Vasiliadis ◽  
Nikolaos Koukoulias ◽  
Konstantinos Katakalos
Keyword(s):  
Tissue Engineering ◽  
Three Dimensional ◽  
In Vivo Studies ◽  
Cell Based Therapy ◽  
Meniscus Tissue ◽  
The Future ◽  
Healthy Knee ◽  
3D Printed

The meniscus is a critical component of a healthy knee joint. It is a complex and vital fibrocartilaginous tissue that maintains appropriate biomechanics. Injuries of the meniscus, particularly in the inner region, rarely heal and usually progress into structural breakdown, followed by meniscus deterioration and initiation of osteoarthritis. Conventional therapies range from conservative treatment, to partial meniscectomy and even meniscus transplantation. All the above have high long-term failure rates, with recurrence of symptoms. This communication presents a brief account of in vitro and in vivo studies and describes recent developments in the field of 3D-printed scaffolds for meniscus tissue engineering. Current research in meniscal tissue engineering tries to combine polymeric biomaterials, cell-based therapy, growth factors, and 3D-printed scaffolds to promote the healing of meniscal defects. Today, 3D-printing technology represents a big opportunity in the orthopaedic world to create more specific implants, enabling the rapid production of meniscal scaffolds and changing the way that orthopaedic surgeons plan procedures. In the future, 3D-printed meniscal scaffolds are likely to be available and will also be suitable substitutes in clinical applications, in an attempt to imitate the complexity of the native meniscus.

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

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