|
 
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| REVIEW ARTICLE |
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| Year : 2022 | Volume
: 8
| Issue : 1 | Page : 8 |
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Application of three-dimensional bioprinting technology in orthopedics
Shimin Li, Xiao Ouyang
Department of Orthopaedics, Xuzhou Hospital Affiliated to Jiangsu University, Xuzhou, Jiangsu, China
| Date of Submission | 27-Apr-2021 |
| Date of Decision | 20-Jun-2021 |
| Date of Acceptance | 06-Aug-2021 |
| Date of Web Publication | 21-Apr-2022 |
Correspondence Address:
Xiao Ouyang
Xuzhou Hospital Affiliated to Jiangsu University, 131 Huancheng Road, Xuzhou, Jiangsu
China
 Source of Support: None, Conflict of Interest: None  | Check |
DOI: 10.4103/digm.digm_9_21
The treatment of bone defects, especially large-area bone defects caused by trauma, congenital malformations, senile diseases, and other factors, is often the key and difficult point of orthopedic diseases, which often brings a lot of troubles in the daily work of orthopedic physicians. Bone tissue engineering attempts to repair bone defects using three-dimensional (3D) bioprinted living tissue, and induces osteoblasts to differentiate and proliferate by placing biological scaffolds, thus finally forming bone tissue commensurate with the original tissue functional structure, reducing the difficulty of surgery. Compared with the traditional bone grafting surgery, it causes less trauma to patients. It is an emerging technology with crossover and cutting edge, and has huge application space and good application prospect in biomedical field. In this article, the clinical application of 3D bioprinting technology in various orthopedic fields in recent 5 years is briefly discussed.
Keywords: 3D Bio-materials, Bone trauma, Cartilage damage, Pediatric orthopedics, Spine surgery, Three-dimensional bioprinting technology
How to cite this article:
Li S, Ouyang X. Application of three-dimensional bioprinting technology in orthopedics. Digit Med 2022;8:8 |
| Introduction | |  |
Three-dimensional (3D) biological printing technology accurately arranges various biological materials, tissue cells, and growth factors into a 3D structure according to a specific layout through computer 3D digital imaging and multilevel continuous printing technology so as to interact and exert biological activity, and finally realize biological performance similar to or even better than that of target tissues and organs. Compared with the traditional 3D printing technology, 3D biological printing technology due to the particularity of its materials, in terms of personalized built-in, has an irreplaceable position, as a print built-in essential “biological ink” tends to have the following characteristics: (1) good biocompatibility and biodegradability; (2) certain biomechanical strength; (3) plasticity; (4) ability to induce differentiation and regeneration of cells or tissues and effective surface activity; (5) no toxicity and immunogenicity; (6) appropriate 3D pore size and porosity.[1]
Hydrogels are the most common bio-linked scaffolds that absorb and retain large amounts of water.[2] They are flexible enough for cells, which can sense their existence and move toward them preferentially,[3] then freely migrate and interact in that stereo porou flexible network.[4],[5],[6] Hydrogels with different molecular weights and stimulating factors can recruit stem cells from bone marrow and synovium[7],[8] and promote cell migration and regulate cell proliferation.[9],[10],[11],[12],[13],[14],[15],[16] The gap between each mesh is usually between 100 and 300 nm, even larger, which is beneficial to the formation of new bone and capillary vessels.[17],[18],[19],[20],[21],[22]
The “bio-ink” is printed by a 3D bioprinter into a bioscaffold that fits perfectly with the implanted site and conforms to the stress characteristics, containing a loose porous microstructure, and the surface is adhered with bioactive factors which are convenient for cell adhesion and migration, promote cell differentiation and proliferation and the like, “see cells” will be accurately colonized in that biological scaffold material according to a certain spatial structure to obtain nutrients needed for growth and differentiation. While the scaffold is degraded intracorporeal, the “seed cells” will gradually grow and differentiate into structures with similar biological functions to the original tissues. Although this technology is in its initial stage, many scholars have conducted relevant research in clinical application, the following is a brief overview of the application of 3D bioprinting technology in various subprofessional disciplines of orthopedics and the problems currently faced.
| Application of Three-Dimensional Bioprinting Technology in Joint Surgery | | |
Traditional joint replacement is still dominant in treating most middle-aged and elderly joint diseases, especially femoral neck fracture, intertrochanteric fracture, and knee osteoarthritis. However, artificial prostheses have their service life, ranging from 5 to 15 years. When the prostheses are worn to a certain degree, replacement surgery needs to be performed again, but the replacement surgery is more difficult, for this kind of young patients. In order to ensure their quality of life, conservative treatment is the main treatment, and joint replacement can only be performed when they are at a suitable age or must undergo surgery. Using bioactive joint replacement with 3D bioprinting has unique advantages in such situations.
According to the image information collected before operation, the bioactive joint is printed and placed into the biological scaffold–osteoblast complex which matches the local anatomy of the patient and conforms to the stress characteristics of the site. While the bioactive scaffold is gradually degraded in the body, osteoblasts differentiate and proliferate, fuse with the patient's own tissue, and play the same role instead of the original joint. Compared with the traditional joint replacement surgery, it has less damage to the lesion site and its adjacent tissues, and the implanted artificial prosthesis has a higher matching degree. Studies have shown that the bioscaffold–osteoblast complex can be equipped with broad-spectrum antibiotic dressing, which not only meets the anti-loosening requirements of postoperative joints but also provides anti-infection guarantee,[23],[24] it can greatly avoid the possibility of secondary operation after postoperative infection and poor joint reduction. Sun et al.[25] used a GDF5-bound BMSC loaded scaffold in repairing rat osteoarthritis model through 3d bioprinting. Compared with the control group, the GDF5-bound scaffold showed better cartilage repair effect. Meanwhile, in rabbit knee joint transplantation, 3D bioprinted GDF 5-bound scaffold loaded with bone marrow stromal cells provided long-term cartilage protection for rabbit knee joint.[25]
Although the current 3D bioprinting technology has been able to produce osteochondral models similar to human body structure, there are still many problems in practical clinical application due to imperfect material limitations. The harsh conditions such as high temperature and high pressure in the production process may affect the viability of cells,[26] and the mechanical properties of printed cartilage tissue cannot meet the normal load-bearing of human body and the friction between bones, and the control of the degradation rate of bioactive scaffolds and the poor load-bearing of obese patients[27] are the implementation problems that limit the wide application of 3D bioprinting technology. With the development of “bio-ink,” the applicable population and influence of bioactive joint replacement will be wider and wider.
| Application of Biological Three-Dimensional Printing Technology in Cartilage Repair | | |
Cartilage is an important part of human body to resist pressure or stretching and reduce the direct friction and impact between bones. However, there are no nourishing blood vessels in adults' cartilage tissue, and its self-healing ability is poor, so the clinical treatment effect of cartilage tissue injury is often unsatisfactory.
With the development of the research on 3D bioprinting technology, various “bio-inks” have been developed and applied in clinical. At present, the “bio-ink” used in cartilage repair is mainly divided into natural biomaterials and synthetic biomaterials.[28]
Natural biomaterials
Agarose, alginate, fibrin, collagen, and hyaluronic acid[29],[30],[31],[32] are all commonly used “bio-inks” in current 3D bioprinting. These substances have good biocompatibility, fast degradation speed, less human reaction, and adverse reactions, which can promote osteoblast migration and produce extracellular molecules through specific surface receptors, and achieve the purpose of cell proliferation. However, their mechanical strength is low, and if they degrade too fast, they cannot achieve the desired therapeutic effect.
Synthetic biomaterials
The most common ones are polyethylene glycol (PEG), polylactic acid (PLA), polycaprolactone (PCL), hydroxyapatite (HA), PLA-glycolic acid, and polyurethane (PU).[33],[34],[35],[36],[37] This kind of material has good mechanical properties, little rejection from human body, but poor water solubility.
Generally speaking, synthetic biomaterials have better biocompatibility than natural ones and are more conducive to cell growth and differentiation.[38] When designing cartilage repair bio-ink, both its mechanical properties and biological benefits should be considered, and a single material often cannot achieve a satisfactory result. Therefore, researchers often mix two or more polymer materials to prepare cartilage bioprinting ink, which plays a complementary role.[39],[40] Taking alginates and HA s as examples, their biocompatibility, toughness, and degradation rate are more conducive to the formation of 3D porous structure.[41],[42] Alginate salt and PEG polymer covalent cross-linked through Ca2+ and decomposed by UV irradiation so as to form a PEG grid with good elasticity.[12],[43],[44] As a knee joint repair material, HA can stimulate chondrocyte metabolism, synthesize cartilage matrix components, and inhibit cartilage degenerative enzymes and inflammatory processes. They are equipped with intra-articular injection gels, and they also have the characteristics of high swelling rate needed to cover the joint surface to meet the requirements of cartilage repair.
This alginate-PEGDA hydrogel also has high stretchability and toughness, and can provide enough strength and rigidity to play a role between bone and cartilage remodeling[45],[46] Cui et al.[47] used the complex of PEG dimethacrylate and gelatin methacrylate to prepare PEG-GeIMA hydrogel scaffold, which was loaded with human mesenchymal stem cells and found that its osteogenic effect and chondrogenic differentiation promotion were stronger than before.
The biological scaffold printed by Li et al. and Wei et al.[48],[49] after mixing silk fibroin, gelatin, and hyaluronic acid with platelet-rich plasma dressing has been proved to be capable of promoting the differentiation and proliferation of adipose-derived mesenchymal stem cells and chondrocytes.
Li et al.[50] used alginate and PEG as 3D bioprinting ink to repair an oval defect with a volume of 39.29 mm3, and printed cartilage highly matched with the defect. The average printing time was only 36.61 s. The results of these studies show that the customized hydrogel printed by 3D biology has great flexibility, can better meet the characteristics needed for cartilage repair,[51],[52] and provides another strategy for cartilage repair.
| Application of Biological Three-Dimensional Printing Technology in Traumatic Orthopedics | | |
The repair of bone defects
In our daily life, we often encounter fractures caused by car accidents, falling from a height, severe violence, etc., among which there are many patients with comminuted fractures, which are difficult to treat. Large-scale bone defects, postoperative nonunion or delayed union, and even osteomyelitis are all difficult problems that we need to consider in the treatment process. Zhang et al.[53] used 3D bioprinting technology to print bone matrix gelatin-β-tricalcium phosphate into hierarchical porous scaffolds, which is beneficial to the growth of new blood vessels. Experiments have proved that the newly generated bone cells are highly expressed with the genes related to new blood vessels, which proves that they play an important role in the process of osteoblast formation and angiogenesis. Zhao et al.[54] carried the powder of L-PLA, levofloxacin, and tobramycin on the bone implant, and developed a controlled-release multidrug artificial bone, which achieved good results when used alone, and also achieved satisfactory results when used with titanium mesh. Byambaa et al.[55] co-cultured human bone marrow mesenchymal stem cells and human umbilical vein endothelial cells to develop a new hydrogel, which can promote angiogenesis and bone formation in large bone defects. After 3 weeks of culture in vitro, it showed high cell viability, proliferation rate, and structural stability. The results also showed that mature trabeculae were formed after 21 days in vitro culture. Fedorovich et al.[56] printed alginate gel and cell matrix into vascularized scaffold, filled with endothelial cell precursors and mesenchymal stem cells, and implanted into mice subcutaneous to test the formation of derived bone. Osteoblasts and ectopic bone deposition were found after 6 weeks.
Soft-tissue repair
Fracture is often accompanied by adjacent soft-tissue and skin injury, which often induces inflammation and affects fracture healing. 3D bioprinting technology can print bioactive tissues or organs, and cooperate with bioprinting implants to improve the angiogenesis rate and have a good effect on fracture healing. Such as Tan et al.[57] provided personalized implants for patients with finger or toe defects, which achieved good therapeutic effects and improved the quality of life of patients. Kim et al.[58] added skin-derived extracellular matrix to 3D bioprinting stent, which could observe the formation of new blood vessels and accelerate wound healing. Yokota et al.[59] used 3D bioprinting technology to make keratinocytes and fibroblasts into artificial skin similar in structure and function to human skin, providing a new idea for skin transplantation. Gomez-Barrena et al.[60] combined 3D bioprinting stent with recombinant human growth factor and/or stem cells to solve the problem of insufficient growth of implanted neovascularization. Verboket et al.[61] implanted bone marrow mesenchymal stem cells into bone substitutes, which were used to fill the poor healing caused by unconnected bones after traditional surgery.
Although most experimental studies of 3D bioprinting tissue technology have not been applied to clinical practice, through the unremitting efforts of researchers, its broad development prospects are expected, and it will play the advantages of personalized and precise treatment in the future treatment of traumatic surgical diseases.
| Application of Biological Three-Dimensional Printing Technology in Spinal Surgery | | |
The spine is mainly responsible for protecting the spinal cord and bearing part of the weight of human body. The structure of this part is complex, involving many important nerve vessels, and the treatment requirements are very detailed. Spinal surgery patients are more common in spinal cord dysfunction caused by trauma, tumor, intervertebral disc degeneration, etc., among which intervertebral disc degeneration is the most important cause, and some scholars have started relevant research on intervertebral disc substitutes.
Rosenzweig et al.[62] planted articular chondrocytes and nucleus pulposus cells in acrylonitrile butadiene styrene-PLA composite scaffold. After 3 weeks, it was found that many proteoglycans and type II collagen adhered to the scaffold, which reflected that chondrocytes and nucleus pulposus cells grew and differentiated well. The compound may be used as an intervertebral disc substitute to treat various intervertebral disc degenerations. Whatley et al.[63] printed PU as intervertebral disc scaffold. The research shows that this material has a fast degradation rate, which is beneficial to cell adhesion and proliferation. Gluais et al.[64] successfully developed a cell-free PCL fiber scaffold using sheep AF-defects model. This implant could potentially act as a 3D scaffold that induces the production of AF-like tissue and that could prevent IVD recurrent herniation, as well as neural and vascular ingrowth, and that might also slow the IVD degeneration process.
In addition to the intervertebral disc substitute, Gullbrand et al.[65] also carried out the experiment of artificial vertebral replacement. They put an endplate-modified DAPS (eDAPS) into a goat cervical disc replacement model. Results showed that the eDAPS composition and structure were maintained up to 8 weeks within the disc space, the imaging data showed that the position and intervertebral space of the prosthesis were good, and the mechanical function of the eDAPS implants was similar to native disc mechanical properties.
The feasibility of 3D bioprinting technology has been proved by cell experiments and animal experiments, and its development prospect is very optimistic. With more and more animal simulation operations, more and more valuable experience has been accumulated, and 3D bioprinting technology will eventually gain its own place in spinal surgery.
| Application of Biological Three-Dimensional Printing Technology in Pediatric Orthopedics | | |
The treatment of bone defects
In the treatment of children's bone tumors, a large area of bone is often removed, even including epiphysis and metaphysis. A few serious comminuted fractures will also lead to the loss of a large area of bone mass, which will make children's bone growth disorder and seriously affect their quality of life. Some researchers solved such problems by using bony inlays. DIPY-3DPBC scaffold was used to repair children's craniofacial defect model. Six months later, the results showed that there was significant bone regeneration in alveolar bone and alveolar bone defect, and there was no significant difference in trabecular thickness among regenerated bone, bone graft, and natural bone.[66] Lu et al.[67] showed that the combination of β-tricalcium phosphate bioceramics and vascularized fibula can restore the function of lower limbs, promote bone healing, and reduce postoperative complications in repairing bone defects after resection of malignant tumors of lower limbs. In another situation, Bose et al. have implanted 3D printed bioabsorbable airway splint into infants.[68]
Repair of metaphyseal injury
Children's metaphyseal end is composed of cancellous bone, which is covered with thin cortical bone, with weak anatomical structure and easy to fracture. If a bone bridge is formed after injury, it is easy to form deformity in future development, which has a great impact on patients. 3D bioprinting technology cannot print out the substitute materials of metaphyseal tissue for the time being, and plays the roles of preoperative simulation, intraoperative positioning, postoperative auxiliary treatment, and so on in metaphyseal injury repair surgery.
Although the short-term treatment effect of 3D bioprinted prosthetic implant is good, the long-term effect is not satisfied because children are still growing.[69] Developing implants that meet the needs of children's bone growth and development is a difficult point for 3D bioprinting technology to make great progress in pediatric orthopedics.
In addition, 3D bioprinting has made some progress in bone tumor research. 3D bioprinting model can simulate cell–cell and cell–matrix interaction in three dimensions, and integrate the vascular system to analyze how cancer cells grow and other carcinogenic events.[70],[71] At present, 3D biomimetic bone matrix has been used to create a bone metastasis model of breast cancer, which has a bone-like microenvironment and can be used to analyze the relationship among breast cancer cells, human bone marrow mesenchymal stem cells, and osteoblasts.[72] Zhu et al.[73] used a 3D printed nano-ink, made of HA nanoparticles suspended in hydrogel, to simulate the specific environment of bone to study the invasion of breast cancer on bone.
| Problems Faced By Three-Dimensional Bioprinting Technology at Present | | |
“Bio-ink” is an important part in the process of 3D bioprinting. Although some progress has been made in the research and development of “bio-ink,” there is still a lack of printing materials that can perfectly fit the human body, and the structural strength of the built-in objects generally cannot meet the needs of the human body.
In addition, bio-3D printing technology cannot print cross-category materials at present, and can only produce products with relatively single function and structure. Furthermore, the printing accuracy of 3D printers of different levels and different manufacturers is quite different, especially the commercial desktop 3D printers, whose printing accuracy cannot meet the requirements of orthopedic surgical implants, and such 3D printers are expensive, and their operation processes also require specialized personnel to spend time to learn, and the maintenance and repair of machines is also a huge expense, which makes the price of printed products always high, which is the most important reason for its limited development.[74] Besides, how to ensure the absolute sterility of bone and cartilage tissue substitutes and avoid iatrogenic damage to patients are also the key to the wide application of 3D bioprinting technology in clinical practice.
How to arrange the biological materials, seed cells, and growth factors of the printed tissues and organs so as to ensure the cell activity and meet the basic demands of patients in daily life in the future is another poser for 3D biological printing technology. These requirements may seem simple, but they test the researchers' knowledge storage and the integration ability in various disciplines and technologies. Only after a large number of related experiments, can they obtain a nearly perfect answer. With the improvement of the level of science and technology, improve the precision of equipment at the same time industry personnel operating skills will also be gradually improved, holiday time will be able to overcome the above problems.
| Conclusions | | |
As a cutting-edge technology, 3D bioprinting can only print single-cell tissues with no specific biological function now. There are still many problems should to be discussed in the practical application of orthopedics, but it still has potential value that cannot be ignored. Fast, accurate and personalized are the most distinctive features. According to relevant data, there are about 40 million patients with joint diseases in China,[75] and joint replacements are also one of the most common operations in orthopedics today. Due to everyone's body structure and pathophysiology is different, the demand for individualized treatment provides a broad performance stage for 3D bioprinting technology. How to customize personalized hip implant stents and treatment of AIDS according to patients' respective anatomical morphology, pathophysiology and treatment needs is a feasible direction for 3D bioprinting; In addition, because of its degradation–regeneration mechanism, 3D bioprinting stent can get rid of the restriction of built-in objects on children's growth and development, and make a great breakthrough in this field, so as to truly achieve personalized medicine and precise medicine. In addition, 3D bioprinting technology is also full of infinite possibilities in human bone replacement. With the deepening of the research on 3D bioprinting technology, with the cooperation of many researchers, the technology will gradually mature, and more and more valuable experiences will be summarized, which will have a tremendous impact on the treatment of orthopedic diseases in the future.
Financial support and sponsorship
Nil.
Conflicts of interest
There are no conflicts of interest.
| References | | |
| 1. | Zhao F, Cheng J, Zhang J, Yu H, Dai W, Yan W, et al. Comparison of three different acidic solutions in tendon decellularized extracellular matrix bio-ink fabrication for 3D cell printing. Acta Biomater 2021;131:262-75.  |
| 2. | Hospodiuk M, Dey M, Sosnoski D, Ozbolat IT. The bioink: A comprehensive review on bioprintable materials. Biotechnol Adv 2017;35:217-39. |
| 3. | Lo CM, Wang HB, Dembo M, Wang YL. Cell movement is guided by the rigidity of the substrate. Biophys J 2000;79:144-52. |
| 4. | Ye Q, Zünd G, Benedikt P, Jockenhoevel S, Hoerstrup SP, Sakyama S, et al. Fibrin gel as a three dimensional matrix in cardiovascular tissue engineering. Eur J Cardio Thorac Surg 2000;17:587-91. |
| 5. | Drury JL, Mooney DJ. Hydrogels for tissue engineering: Scaffold design variables and applications. Biomaterials 2003;24:4337-51. |
| 6. | Rajan N, Habermehl J, Coté MF, Doillon CJ, Mantovani D. Preparation of ready-to-use, storable and reconstituted type I collagen from rat tail tendon for tissue engineering applications. Nat Protoc 2006;1:2753-8. |
| 7. | Shi D, Xu X, Ye Y, Song K, Cheng Y, Di J, et al. Photo-cross-linked scaffold with kartogenin-encapsulated nanoparticles for cartilage regeneration. ACS Nano 2016;10:1292-9. |
| 8. | Chung C, Burdick JA. Engineering cartilage tissue. Adv Drug Deliv Rev 2008;60:243-62. |
| 9. | Kawada A, Hiura N, Tajima S, Takahara H. Alginate oligosaccharides stimulate VEGF-mediated growth and migration of human endothelial cells. Arch Dermatol Res 1999;291:542-7. |
| 10. | Kim M, Jung WK, Kim G. Bio-composites composed of a solid free-form fabricated polycaprolactone and alginate-releasing bone morphogenic protein and bone formation peptide for bone tissue regeneration. Bioprocess Biosyst Eng 2013;36:1725-34. |
| 11. | Moshaverinia A, Ansari S, Chen C, Xu X, Akiyama K, Snead ML, et al. Co-encapsulation of anti-BMP2 monoclonal antibody and mesenchymal stem cells in alginate microspheres for bone tissue engineering. Biomaterials 2013;34:6572-9. |
| 12. | Venkatesan J, Bhatnagar I, Manivasagan P, Kang KH, Kim SK. Alginate composites for bone tissue engineering: A review. Int J Biol Macromol 2015;72:269-81. |
| 13. | Guillaume O, Naqvi SM, Lennon K, Buckley CT. Enhancing cell migration in shape-memory alginate–collagen composite scaffolds: In vitro and ex vivo assessment for intervertebral disc repair. J Biomater Appl 2015;29:1230-46. |
| 14. | Fraser JR, Laurent TC, Pertoft H, Baxter E. Plasma clearance, tissue distribution and metabolism of hyaluronic acid injected intravenously in the rabbit. Biochem J 1981;200:415-24. |
| 15. | Andreutti D, Geinoz A, Gabbiani G. Effect of hyaluronic acid on migration, proliferation and alpha-smooth muscle actin expression by cultured rat and human fibroblasts. J Submicrosc Cytol Pathol 1999;31:173-7. |
| 16. | Xu W, Qian J, Zhang Y, Suo A, Cui N, Wang J, et al. A double-network poly (Nε-acryloyl L-lysine)/hyaluronic acid hydrogel as a mimic of the breast tumor microenvironment. Acta Biomater 2016;33:131-41. |
| 17. | Wang W, Yeung KW. Bone grafts and biomaterials substitutes for bone defect repair: A review. Bioact Mater 2017;2:224-47. |
| 18. | Zhang L, Yang G, Johnson BN, Jia X. Three-dimensional (3D) printed scaffold and material selection for bone repair. Acta Biomater 2019;84:16-33. |
| 19. | Karageorgiou V, Kaplan D. Porosity of 3D biomaterial scaffolds and osteogenesis. Biomaterials 2005;26:5474-91. |
| 20. | Al-Munajjed AA, Hien M, Kujat R, Gleeson JP, Hammer J. Influence of pore size on tensile strength, permeability and porosity of hyaluronan-collagen scaffolds. J Mater Sci Mater Med 2008;19:2859-64. |
| 21. | Goriainov V, Cook R, M Latham J, G Dunlop D, Oreffo RO. Bone and metal: An orthopaedic perspective on osseointegration of metals. Acta Biomater 2014;10:4043-57. |
| 22. | Fujita T. Hierarchical nanoporous metals as a path toward the ultimate three-dimensional functionality. Sci Technol Adv Mater 2017;18:724-40. |
| 23. | Billiet T, Vandenhaute M, Schelfhout J, Van Vlierberghe S, Dubruel P. A review of trends and limitations in hydrogel-rapid prototyping for tissue engineering. Biomaterials 2012;33:6020-41. |
| 24. | Aldrich A, Kuss MA, Duan B, Kielian T. 3D bioprinted scaffolds containing viable macrophages and antibiotics promote clearance of staphylococcus aureus craniotomy-associated biofilm infection. ACS Appl Mater Interfaces 2019;11:12298-307. |
| 25. | Sun Y, You Y, Jiang W, Zhai Z, Dai K. 3D-bioprinting a genetically inspired cartilage scaffold with GDF5-conjugated BMSC-laden hydrogel and polymer for cartilage repair. Theranostics 2019;9:6949-61. |
| 26. | Gu Y, Zhang L, Du X, Fan Z, Wang L, Sun W, et al. Reversible physical crosslinking strategy with optimal temperature for 3D bioprinting of human chondrocyte-laden gelatin methacryloyl bioink. J Biomater Appl 2018;33:609-18. |
| 27. | Bociaga D, Bartniak M, Grabarczyk J, Przybyszewska K. Sodium alginate/gelatine hydrogels for direct bioprinting-the effect of composition selection and applied solvents on the bioink properties. Materials (Basel) 2019;12:E2669. |
| 28. | Mondschein RJ, Kanitkar A, Williams CB, Verbridge SS, Long TE. Polymer structure-property requirements for stereolithographic 3D printing of soft tissue engineering scaffolds. Biomaterials 2017;140:170-88. |
| 29. | Zheng X, Huang J, Lin J, Yang D, Xu T, Chen D, Zan X, Wu A. 3D bioprinting in orthopedics translational research. J Biomater Sci Polym Ed 2019;30:1172-87. |
| 30. | Hunt NC, Grover LM. Cell encapsulation using biopolymer gels for regenerative medicine. Biotechnol Lett 2010;32:733-42. |
| 31. | Li Z, Kawashita M. Current progress in inorganic artificial biomaterials. J Artif Organs 2011;14:163-70. |
| 32. | de Melo BA, Jodat YA, Cruz EM, Benincasa JC, Shin SR, Porcionatto MA. Strategies to use fibrinogen as bioink for 3D bioprinting fibrin-based soft and hard tissues. Acta Biomater 2020;117:60-76. |
| 33. | Hutmacher DW, Schantz T, Zein I, Ng KW, Teoh SH, Tan KC. Mechanical properties and cell cultural response of polycaprolactone scaffolds designed and fabricated via fused deposition modeling. J Biomed Mater Res 2001;55:203-16. |
| 34. | Sherwood JK, Riley SL, Palazzolo R, Brown SC, Monkhouse DC, Coates M, et al. A three-dimensional osteochondral composite scaffold for articular cartilage repair. Biomaterials 2002;23:4739-51. |
| 35. | Dietzel JM, Kleinmeyer J, Harris D, Beck Tan NC. The effect of processing variables on the morphology of electrospun nanofibers and textiles. Polymer (Guildf) 2001;42:261-72. |
| 36. | Park JS, Kim JM, Lee SJ, Lee SG, Jeong YK, Kim SE, et al. Surface hydrolysis of fibrous poly (ε-caprolactone) scaffolds for enhanced osteoblast adhesion and proliferation. Macromol Res 2007;15:424-9. |
| 37. | Oh SH, Kang SG, Kim ES, Cho SH, Lee JH. Fabrication and characterization of hydrophilic poly(lactic-co-glycolic acid)/poly(vinyl alcohol) blend cell scaffolds by melt-molding particulate-leaching method. Biomaterials 2003;24:4011-21. |
| 38. | Panwar A, Tan LP. Current status of bioinks for micro-extrusion-based 3D bioprinting. Molecules 2016;21:E685. |
| 39. | Takahashi R, Sun TL, Saruwatari Y, Kurokawa T, King DR, Gong JP. Creating stiff, tough, and functional hydrogel composites with low-melting-point alloys. Adv Mater 2018;30:e1706885. |
| 40. | Kim MH, Kim BS, Park H, Lee J, Park WH. Injectable methylcellulose hydrogel containing calcium phosphate nanoparticles for bone regeneration. Int J Biol Macromol 2018;109:57-64. |
| 41. | Pawar SN, Edgar KJ. Alginate derivatization: A review of chemistry, properties and applications. Biomaterials 2012;33:3279-305. |
| 42. | Mooney KY, David J. Alginate: properties and biomedical applications. Prog Polym Sci 2012;37:106-26. |
| 43. | Hong S, Sycks D, Chan HF, Lin S, Lopez GP, Guilak F, et al. 3D printing: 3D printing of highly stretchable and tough hydrogels into complex, cellularized structures. Adv Mater 2015;27:4034. |
| 44. | Li C, Qian Y, Zhao S, Yin Y, Li J. Alginate/PEG based microcarriers with cleavable crosslinkage for expansion and non-invasive harvest of human umbilical cord blood mesenchymal stem cells. Mater Sci Eng C Mater Biol Appl 2016;64:43-53. |
| 45. | Raeissadat SA, Rayegani SM, Hassanabadi H, Fathi M, Ghorbani E, Babaee M, et al. Knee osteoarthritis injection choices: Platelet- rich plasma (PRP) Versus hyaluronic acid (A one-year randomized clinical trial). Clin Med Insights Arthritis Musculoskelet Disord 2015;8:1-8. |
| 46. | Chou AI, Akintoye SO, Nicoll SB. Photo-crosslinked alginate hydrogels support enhanced matrix accumulation by nucleus pulposus cells in vivo. Osteoarthritis Cartilage 2009;17:1377-84. |
| 47. | Cui X, Breitenkamp K, Finn MG, Lotz M, D'Lima DD. Direct human cartilage repair using three-dimensional bioprinting technology. Tissue Eng Part A 2012;18:1304-12. |
| 48. | Li Z, Jia S, Xiong Z, Long Q, Yan S, Hao F, et al. 3D-printed scaffolds with calcified layer for osteochondral tissue engineering. J Biosci Bioeng 2018;126:389-96. |
| 49. | Wei L, Wu S, Kuss M, Jiang X, Sun R, Patrick R, et al. 3D printing of silk fibroin-based hybrid scaffold treated with platelet rich plasma for bone tissue engineering. Bioact Mater 2019;4:256-60. |
| 50. | Li L, Yu F, Shi J, Shen S, Teng H, Yang J, et al. In situ repair of bone and cartilage defects using 3D scanning and 3D printing. Sci Rep 2017;7:9416. |
| 51. | Grigolo B, Roseti L, Fiorini M, Fini M, Giavaresi G, Aldini NN, et al. Transplantation of chondrocytes seeded on a hyaluronan derivative (hyaff-11) into cartilage defects in rabbits. Biomaterials 2001;22:2417-24. |
| 52. | Masters KS, Shah DN, Leinwand LA, Anseth KS. Crosslinked hyaluronan scaffolds as a biologically active carrier for valvular interstitial cells. Biomaterials 2005;26:2517-25. |
| 53. | Zhang Y, Xia L, Zhai D, Shi M, Luo Y, Feng C, et al. Mesoporous bioactive glass nanolayer-functionalized 3D-printed scaffolds for accelerating osteogenesis and angiogenesis. Nanoscale 2015;7:19207-21. |
| 54. | Zhao Y, Li Y, Mao S, Sun W, Yao R. The influence of printing parameters on cell survival rate and printability in microextrusion-based 3D cell printing technology. Biofabrication 2015;7:045002. |
| 55. | Byambaa B, Annabi N, Yue K, Trujillo-de Santiago G, Alvarez MM, Jia W, et al. Bioprinted osteogenic and vasculogenic patterns for engineering 3D bone tissue. Adv Healthc Mater 2017;6:1700015. |
| 56. | Fedorovich NE, De Wijn JR, Verbout AJ, Alblas J, Dhert WJ. Three-dimensional fiber deposition of cell-laden, viable, patterned constructs for bone tissue printing. Tissue Eng Part A 2008;14:127-33. |
| 57. | Tan H, Yang K, Wei P, Zhang G, Dimitriou D, Xu L, et al. A novel preoperative planning technique using a combination of CT angiography and three-dimensional printing for complex toe-to-hand reconstruction. J Reconstr Microsurg 2015;31:369-77. |
| 58. | Kim BS, Kwon YW, Kong JS, Park GT, Gao G, Han W, et al. 3D cell printing of in vitro stabilized skin model and in vivo pre-vascularized skin patch using tissue-specific extracellular matrix bioink: A step towards advanced skin tissue engineering. Biomaterials 2018;168:38-53. |
| 59. | Yokota K, Matsumoto T, Murakami Y, Ando K, Akiyama M. Three-dimensional modeling and printing facilitate preoperative simulation and planning in skin surgery. J Dermatol 2016;43:1450-1. |
| 60. | Gomez-Barrena E, Rosset P, Gebhard F, Hernigou P, Baldini N, Rouard H, et al. Feasibility and safety of treating non-unions in tibia, femur and humerus with autologous, expanded, bone marrow-derived mesenchymal stromal cells associated with biphasic calcium phosphate biomaterials in a multicentric, non-comparative trial. Biomaterials 2019;196:100-8. |
| 61. | Verboket R, Leiblein M, Seebach C, Nau C, Janko M, Bellen M, et al. Autologous cell-based therapy for treatment of large bone defects: From bench to bedside. Eur J Trauma Emerg Surg 2018;44:649-65. |
| 62. | Rosenzweig DH, Carelli E, Steffen T, Jarzem P, Haglund L. 3D-printed ABS and PLA scaffolds for cartilage and nucleus pulposus tissue regeneration. Int J Mol Sci 2015;16:15118-35. |
| 63. | Whatley BR, Kuo J, Shuai C, Damon BJ, Wen X. Fabrication of a biomimetic elastic intervertebral disk scaffold using additive manufacturing. Biofabrication 2011;3:015004. |
| 64. | Gluais M, Clouet J, Fusellier M, Decante C, Moraru C, Dutilleul M, et al. In vitro and in vivo evaluation of an electrospun-aligned microfibrous implant for Annulus fibrosus repair. Biomaterials. 2019;205:81-93. |
| 65. | Gullbrand SE, Ashinsky BG, Bonnevie ED, Kim DH, Engiles JB, Smith LJ, et al. Long-term mechanical function and integration of an implanted tissue-engineered intervertebral disc. Sci Transl Med 2018;10:eaau0670. |
| 66. | Wang MM, Flores RL, Witek L, Torroni A, Ibrahim A, Wang Z, et al. Dipyridamole-loaded 3D-printed bioceramic scaffolds stimulate pediatric bone regeneration in vivo without disruption of craniofacial growth through facial maturity. Sci Rep 2019;9:18439. |
| 67. | Lu Y, Chen G, Long Z, Li M, Ji C, Wang F, et al. Novel 3D-printed prosthetic composite for reconstruction of massive bone defects in lower extremities after malignant tumor resection. J Bone Oncol 2019;16:100220. |
| 68. | Bose S, Vahabzadeh S, Bandyopadhyay A. Bone tissue engineering using 3D printing. Mater Today 2013;16:496-504. |
| 69. | Xue K, Qi L, Zhou G, Liu K. A two-step method of constructing mature cartilage using bone marrow-derived mesenchymal stem cells. Cells Tissues Organs 2013;197:484-95. |
| 70. | Qiao H, Tang T. Engineering 3D approaches to model the dynamic microenvironments of cancer bone metastasis. Bone Res 2018;6:3. |
| 71. | Ozbolat IT, Peng W, Ozbolat V. Application areas of 3D bioprinting. Drug Discov Today 2016;21:1257-71. |
| 72. | Zhou X, Zhu W, Nowicki M, Miao S, Cui H, Holmes B, et al. 3D bioprinting a cell-laden bone matrix for breast cancer metastasis study. ACS Appl Mater Interfaces 2016;8:30017-26. |
| 73. | Zhu W, Holmes B, Glazer RI, Zhang LG. 3D printed nanocomposite matrix for the study of breast cancer bone metastasis. Nanomedicine 2016;12:69-79. |
| 74. | Mashari A, Montealegre-Gallegos M, Jeganathan J, Yeh L, Qua Hiansen J, Meineri M, et al. Low-cost three-dimensional printed phantom for neuraxial anesthesia training: Development and comparison to a commercial model. PLoS One 2018;13:e0191664. |
| 75. | Xie SH, Wang Q, Wang LQ, Wang L, Song KP, He CQ. Effect of Internet-Based Rehabilitation Programs on Improvement of Painand Physical Functionin Patients with Knee Osteoarthritis: Systematic Reviewand Meta-analysis of Randomized Controlled Trials. J Med Internet Res 2021;23:e21542. |
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