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Relationship between the applied compressive load and the measured tensile load for the 250N runs. Linear trendlines for each cyclic load run are included, with corresponding R2 values. Error bars represent standard deviations. For compressive loads above 10N, significant differences (p < 0.05) were observed between the tensile loads generated in the different scaffold groups.
Source publication
A fiber-reinforced degradable scaffold for replacement of meniscal tissue was designed, fabricated, and mechanically evaluated. The hypotheses were that (1) the fiber network design would share a portion of compressive loads via the generation of circumferential tensile loads, and (2) the scaffold tensile properties would be similar to those of the...
Contexts in source publication
Context 1
... the 250 N cyclic load runs, the average measured tensile load at regular intervals was plotted against the corresponding applied compressive load (Figure 4). For MS500 and MS1000 scaffolds, 24 data points were averaged for the 10 N and 250 N compressive loads. ...
Context 2
... the control group, 6 data points were averaged for 10 N and 250 N, while 11 were averaged for all other loads. A linear relationship was calculated between generated tensile load vs. applied compressive load, and the corresponding trendline and R 2 value are shown in Figure 4 for each scaffold type (MS500, MS1000, blank control). At applied compressive loads above 10 N, the tensile loads generated in each group were significantly different (p < 0.05). ...
Citations
... Potential host tissue fusion Failure in orthopedics [73] Poly(vinyl alcohol) Biocompatibility Non-toxicity Non-carcinogenicity Easy forming ability Easy manufacturing capability Low protein adsorption [74,75] Polyethylene oxide Limited cytotoxicity Fast degradation [76] promote ECM deposition, and accelerate mechanical improvement. Multiple attempts have been made to reproduce the anisotropy of the natural meniscus using synthesis methods like weaving [77], electrospinning [78], and 3D printing [79]. These techniques, however, have never been able to match the mechanics of the native meniscus in both compression and tension, and even fewer have exhibited the capacity to minimize contact stresses on the cartilage under the compressive bearing [80]. ...
... [20] Tensil mekanik özellikleriyle ön plana çıkan tirozin bazlı eriyebilen bir polimer ve kollajenin bileşiminden oluşan bir başka çatı iskelesinin sağlam koyun medial menisküsü ile benzer sertlikte olduğunu ortaya koymuş ve gerilim kuvvetlerinde artışın tibia platosunun kompresif yüklerini azaltarak kıkırdak hasarından koruyucu etki gösterebileceği sonucuna varılmıştır. [21] Tüm yapısı aynı malzemeden üretilen bahsi geçen çatı implantlarının aksine tarafımızca geliştirilen çok katlı meniskal skafoldun her bir tabakası farklı amaçlara yönelik olarak farklı biyomalzemelerin birleşimiyle üretilmişti. Skafoldun en üst tabakası sürtünme ve kompresyona dayanıklılığı arttırmak ve kıkırdak hasarını yavaşlatmak amacıyla polihidroksibütirat-ko-hidroksivalerat (PHBV) yapısında; tibia platosuna temas edecek alt yüzeyi ise hidroksiapatit nanotozları ve stronsiyum ranelat içererek osteokondüktif özelliklere sahip olacak ve implantın tibiaya tutunmasını arttıracak şekilde üretildi. ...
Özet
Menisküslerin korunması ve tamirinin önemi günümüzde çok iyi anlaşılmış olsa da, her zaman mümkün olmamaktadır. Onarılamayan defektler ya da menisektomiler sonrası menisküste oluşan boşluğun doldurulması amacıyla 1990’ların başında çatı (iskele) implantlarının geliştirilmeye başlanmasıyla menisküs cerrahisinde doku mühendisliği uygulamaları büyük bir ivme kazanmıştır. Doku mühendisliği; "doku fonksiyonunu restore etmek, sürdürmek veya iyileştirmek için biyolojik dokuların yerine geçecek malzemelerin geliştirilmesine yönelik hem mühendislik hem de yaşam bilimleri ilkelerinin" kullanılmasını öngören araştırma alanıdır ve temelde çatı implantları, biyoaktif ajanlar (büyüme faktörleri) ve hücreler olmak üzere üç ana değişkenden yararlanır.
Menisküs doku mühendisliğinde farklı malzeme özelliklerine sahip birçok biyomateryalden üretilen çatı implantları, çok sayıda farklılaşmış veya kök hücreler ve bunları uyaracak biyokimyasal, biyomekanik ve gen tedavi yöntemleri hasarlı menisküsün yerini alacak ideal implantın arayışında kullanılmıştır. Geliştirilen bu implantlar ile kıkırdak hasarı ve ileride gelişebilecek osteoartritin de önüne geçilmesi amaçlanmıştır. Ancak hiçbir yapay malzeme menisküsün mekanik özelliklerini sağlamada tam olarak başarılı olamamış ve tüm çabalara rağmen kıkırdağı çok iyi koruduğu kanıtlanarak rutin klinik kullanıma girmiş bir implant henüz tasarlanamamıştır. Günümüzde en umut vadeden yaklaşımlar defekte uygun boyutta üretilebilen, hücre yüklü çatı implantlarının biyomekanik, biyokimyasal ve gen tedavisi yöntemleriyle zenginleştirildiği uygulamalar olarak öne çıkmaktadır. Menisküsün biyolojik ve mekanik yapısını birebir taklit ederek menisküsün yerini alabilecek bir malzemenin hala uzağında olsak da, gelecekte bu yönde katedilecek yol doku mühendisliği uygulamalarından geçecektir.
Anahtar sözcükler: menisküs; doku mühendisliği; çatı implant
Abstract
Although the importance of saving and repairing the menisci is well understood today, it may not always be possible. Tissue engineering applications in meniscal surgery gained momentum with the development of scaffold implants in the early 1990s to fill the defect of the meniscus after irreparable defects or meniscectomies. Tissue engineering is a field of research that envisages the use of "both engineering and life science principles for the development of materials to replace biological tissues to restore, maintain or improve tissue function" and basically utilizes three main variables: scaffolds, cells and bioactive agents (growth factors). Scaffolds produced from several different biomaterials with various material properties; a large number of differentiated or stem cells; gene therapy methods and biochemical or biomechanical stimuli have been applied in meniscus tissue engineering, to develop the ideal implant to replace the damaged meniscus. With these implants, it is aimed to prevent cartilage damage and the risk of future osteoarthritis. However, no artificial material has been fully successful in providing the mechanical properties of the native meniscus, and despite all efforts an implant that has been routinely used in clinics by proving that it protects the cartilage adequately, has not been designed yet. Today, the most promising approaches stand out as applications where cell-loaded scaffolds produced in appropriate sizes for the defect which are enriched with biomechanical, biochemical and gene therapy methods. Although we are still far away from a material that can replace the meniscus by simulating the biological and mechanical structure of the meniscus; in the future the path to be taken in this direction will be through tissue engineering applications.
Key words: meniscus; tissue engineering; scaffolds.
... Some strategies also consist of mimicking the anisotropic organization of the collagen fibers by weaving a 3D matrix of freeze-dried collagen reinforced by a network of synthetic polymer fibers [79]. However, on top of being heavy in terms of manufacturing, it is also not possible to do personalized medicine with this implant as cutting it will not retain the weaving of the fibers. ...
Walking, running, jumping, or even just standing up are habits that we all have to perform in our everyday lives. However, defects in tissues composing the knee joint can drastically alter our ability to complete those simple actions. The knee joint is made up of the interaction between bones (femur, tibia, and patella), tendons, ligaments, and the two menisci (lateral and medial) in order to ensure smooth body movements. The meniscus corresponds to a crescent-shaped fibrocartilaginous tissue, which is found in the knee joint between the femoral condyles and the tibial plateau. It plays a key role in the stability of the knee joint. However, it is quite vulnerable and therefore tears can occur within this tissue and compromise the proper function of the knee. Recently, numerous efforts have been made in order to find solutions to repair and regenerate the meniscus, supported by both bioengineering researchers and orthopedic surgeons. However, due to its poor healing capacity and its complex structure, the reconstruction of the meniscus remains particularly challenging. In this review, the current treatment options will be explained and the possibility of using organoids as building blocks for implant formation or as an in vitro three-dimensional model will be highlighted.
... (C) Multiporous silk scaffold composing of three individual layers with different pore sizes and orientations in each layer (Mandal et al., 2011). (D) Fiber-weaved meniscus scaffold from bovine dermal collagen reinforced by a network of degradable tyrosine-derived polymer fibers (Balint et al., 2012). (E) The 3D-printed polymer network infusing with collagen-hyaluronic acid (Ghodbane et al., 2019b). ...
Meniscus is a semilunar wedge-shaped structure with fibrocartilaginous tissue, which plays an essential role in preventing the deterioration and degeneration of articular cartilage. Lesions or degenerations of it can lead to the change of biomechanical properties in the joints, which ultimately accelerate the degeneration of articular cartilage. Even with the manual intervention, lesions in the avascular region are difficult to be healed. Recent development in regenerative medicine of multipotent stromal cells (MSCs) has been investigated for the significant therapeutic potential in the repair of meniscal injuries. In this review, we provide a summary of the sources of MSCs involved in repairing and regenerative techniques, as well as the discussion of the avenues to utilizing these cells in MSC therapies. Finally, current progress on biomaterial implants was reviewed.
... This strategy allows advanced scaffolds with gross appearance and anatomic size suitable for replacing injured menisci. 48,112,113 While it is challenging for replacing injured meniscus tissues, electrospun scaffolds have found opportunities as wrapping materials to stabilize sutured meniscal tissues and to facilitate repair processes. 114 Suture techniques are commonly used for repairing simple meniscal tears. ...
The meniscus plays a critical role in maintaining the homeostasis, biomechanics, and structural stability of the knee joint. Unfortunately, it is predisposed to damages either from sports-related trauma or age-related degeneration. The meniscus has an inherently limited capacity for tissue regeneration. Self-healing of injured adult menisci only occurs in the peripheral vascularized portion, while the spontaneous repair of the inner avascular region seems never happens. Repair, replacement, and regeneration of menisci through tissue engineering strategies are promising to address this problem. Recently, many scaffolds for meniscus tissue engineering have been proposed for both experimental and preclinical investigations. Electrospinning is a feasible and versatile technique to produce nano- to micro-scale fibers that mimic the microarchitecture of native extracellular matrix and is an effective approach to prepare nanofibrous scaffolds for constructing engineered meniscus. Electrospun scaffolds are reported to be capable of inducing colonization of meniscus cells by modulating local extracellular density and stimulating endogenous regeneration by driving reprogramming of meniscus wound microenvironment. Electrospun nanofibrous scaffolds with tunable mechanical properties, controllable anisotropy, and various porosities have shown promises for meniscus repair and regeneration and will undoubtedly inspire more efforts in exploring effective therapeutic approaches towards clinical applications. In this article, we review the current advances in the use of electrospun nanofibrous scaffolds for meniscus tissue engineering and repair and discuss prospects for future studies.
... Electrospun nanofibers can be a good candidate for biomaterial combining with natural biomaterials for fabricating fiber-reinforced composite scaffolds. This strategy allows advanced scaffolds with gross appreance and anatomic size suitable for replacing injured menisci[66,127,128]. While it is challenging for replacing injured meniscus tissues, electrospun scaffolds have found opportunities as wrapping materials to stabilize sutured meniscal tissues and to facilitate repair processes[129]. ...
The meniscus plays a critical role in maintaining the homeostasis, biomechanics, and structural stability of the knee joint. Unfortunately, it is predisposed to damages either from sports-related trauma or age-related degeneration. The meniscus has an inherently limited capacity for tissue regeneration. Self-healing of injured adult menisci only occurs in the peripheral vascularized portion, while the spontaneous repair of the inner avascular region seems never happens. Repair, replacement, and regeneration of menisci through tissue engineering strategies are promising to address this problem. Recently, many scaffolds for meniscus tissue engineering have been proposed for both experimental and preclinical investigations. Electrospinning is a feasible and versatile technique to produce nano- to micro-scale fibers that mimic the microarchitecture of native extracellular matrix and is an effective approach to prepare nanofibrous scaffolds for constructing engineered meniscus. Electrospun scaffolds are reported to be capable of inducing colonization of meniscus cells by modulating local extracellular density and stimulating endogenous regeneration by driving reprogramming of meniscus wound microenvironment. Electrospun nanofibrous scaffolds with tunable mechanical properties, controllable anisotropy, and various porosities have shown promises for meniscus repair and regeneration and will undoubtedly inspire more efforts in exploring effective therapeutic approaches towards clinical applications. In this article, we review the current advances in the use of electrospun nanofibrous scaffolds for meniscus tissue engineering and repair and discuss prospects for future studies.
... Balint et al. [29] used a different approach in developing a total meniscal substitute where a porous scaffold of collagen-hyaluronan matrix with degradable poly (desaminotyrosyl-tyrosine dodecyl ester dodecanoate) reinforcement fibers was studied. These scaffolds proved to be successful, with considerable mechanical properties suitable as meniscal substitutes; however, implant extrusion remains a challenge [30,31]. ...
The potential use of fiber-reinforced based polycarbonate-urethanes (PCUs) as candidate meniscal substitutes was investigated in this study. Mechanical test pieces were designed and fabricated using a compression molding technique. Ultra-High Molecular Weight Polyethylene (UHMWPE) fibers were impregnated into PCU matrices, and their mechanical and microstructural properties evaluated. In particular, the tensile moduli of the PCUs were found unsuitable, since they were comparatively lower than that of the meniscus, and may not be able to replicate the inherent role of the meniscus effectively. However, the inclusion of fibers produced a substantial increment in the tensile modulus, to a value within a close range measured for meniscus tissues. Increments of up to 227% were calculated with a PCU fiber reinforcement composite. The embedded fibers in the PCU composites enhanced the fracture mechanisms by preventing the brittle failure and plastic deformation exhibited in fractured PCUs. The behavior of the composites in compression varied with respect to the PCU matrix materials. The mechanical characteristics demonstrated by the developed PCU composites suggest that fiber reinforcements have a considerable potential to duplicate the distinct and multifaceted biomechanical roles of the meniscus.
... However, author claimed that further investigations were needed to establish mechanical property and long-term data. Balint et al., developed fiber reinforced collagen scaffold from acid insoluble bovine dermal collagen reinforced by a network of defadable tyrosine derived polymer fibers, poly (desaminotyrosyl-tyrosine dodecyl ester dodecanoate) P(DTD DD) only to determine the tensile properties [59]. ...
Meniscus is a vital functional unit in knee joint. It acts as a lubricating structure, a nutrient transporting structure, as well as shock absorber during jumping, twisting and running and offers stability within the knee joint. It helps in load distribution, in bearing the tensile hoop stresses and balancing by providing a cushion effect between hard surfaces of two bones. Meniscus may be injured in sports, dancing, accident or any over stressed condition. Any meniscal lesion can lead to a gradual development of osteoarthritis or erosion of bone contact surface due to disturbed load and contact stress distribution caused by injury/pain. Once injured, the possibilities of self-repair are rare in avascular region of meniscus, due to lack of blood supply in avascular region. Meniscus has vascular and avascular regions in structure. Majority of the meniscus parts turn avascular with increase in age.
Purpose of this review is to highlight advances in meniscus repair with special focus on tissue engineering using textile/fiber based scaffolds, as well as the recent technical advances in scaffolds for meniscus recon- struction/ regeneration treatment.
... Additionally, anisotropic scaffolds result in improved cellular and extracellular matrix (ECM) alignment, increased ECM deposition, and an increased rate of mechanical improvement. [23][24][25][26][27] Groups have attempted to recreate the anisotropy of the native meniscus utilizing fabrication techniques such as weaving, 28 electrospinning, 29 or 3D-printing. 19,30 However, these devices have never successfully matched the mechanics of the native meniscus in both compression and tension, and fewer have demonstrated the ability to reduce contact stresses on the cartilage under compressive loading. ...
The menisci transmit load by increasing the contact area and decreasing peak contact stresses on the articular surfaces. Meniscal lesions are among the most common orthopedic injuries, and resulting meniscectomies are associated with adverse polycaprolactone contact mechanics changes and, ultimately, an increased likelihood of osteoarthritis. Meniscus scaffolds were fabricated by 3D‐printing a network of circumferential and radial filaments of resorbable polymer (poly(desaminotyrosyl‐tyrosine dodecyl ester dodecanoate)) and infused with collagen‐hyaluronan. The scaffold demonstrated an instantaneous compressive modulus (1.66 ± 0.44 MPa) comparable to native meniscus (1.52 ± 0.59 MPa). The scaffold aggregate modulus (1.33 ± 0.51 MPa) was within 2% of the native value (1.31 ± 0.36 MPa). In tension, the scaffold displayed a comparable stiffness to native tissue (127.6–97.1 N/mm) and an ultimate load of 33% of the native value. Suture pull‐out load of scaffolds (83.1 ± 10.0 N) was within 10% of native values (91.5 ± 15.4 N). Contact stress analysis demonstrated the scaffold reduced peak contact stress by 60–67% and increased contact area by 38%, relative to partial meniscectomy. This is the first meniscal scaffold to match both the axial compressive properties and the circumferential tensile stiffness of the native meniscus. The improvement of joint contact mechanics, relative to partial meniscectomy alone, motivates further investigation using a large animal model. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res B Part B, 2019.
... The fiber network design enabled the scaffold to convert compressive loads into tensile hoop stresses, which mimics the native meniscus. However, the main concern with this scaffold design is that the high fiber density may impede cellular and tissue ingrowth [136]. When GelMA is reinforced Chondrocytes however did show improved fibrocartilaginous tissue deposition however displayed some limitations with regards mechanical properties and fixation [130] Confirmed fibrocartilaginous tissue deposition over 1 year period. ...
This review focuses on the meniscus and the biomaterials involved in meniscal repair and regeneration. Clinical issues associated with the meniscus are introduced and treatment strategies are discussed in terms of biomaterial choice: extracellular matrix materials (ECM), natural materials (ECM-like), synthetic or hybrids of these. These material choices lead to a myriad of options ranging from permanent implants to biodegradable scaffolds (with and without cells, binding ligands and growth factors). The latest chemistries behind emerging candidate materials are discussed in terms of functional modifications, crosslinking agents and techniques. Finally, we review the latest and promising advances associated with bioprinted meniscal implants and the drive toward more functional bioinks with the overall goal of achieving a patient-specific meniscal implant.
