scholarly journals Biochemical Stimulus-Based Strategies for Meniscus Tissue Engineering and Regeneration

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Mingxue Chen ◽  
Weimin Guo ◽  
Shunag Gao ◽  
Chunxiang Hao ◽  
Shi Shen ◽  
...  
Keyword(s):  
Limb Development ◽  
Critical Role ◽  
New Approach ◽  
Meniscus Tissue ◽  
Engineered Tissue ◽  
Seed Cells ◽  
Biomechanical Stimulation ◽  
Meniscus Regeneration ◽  
Therapy Strategies ◽  
Meniscus Injuries

Meniscus injuries are very common and still pose a challenge for the orthopedic surgeon. Meniscus injuries in the inner two-thirds of the meniscus remain incurable. Tissue-engineered meniscus strategies seem to offer a new approach for treating meniscus injuries with a combination of seed cells, scaffolds, and biochemical or biomechanical stimulation. Cell- or scaffold-based strategies play a pivotal role in meniscus regeneration. Similarly, biochemical and biomechanical stimulation are also important. Seed cells and scaffolds can be used to construct a tissue-engineered tissue; however, stimulation to enhance tissue maturation and remodeling is still needed. Such stimulation can be biomechanical or biochemical, but this review focuses only on biochemical stimulation. Growth factors (GFs) are one of the most important forms of biochemical stimulation. Frequently used GFs always play a critical role in normal limb development and growth. Further understanding of the functional mechanism of GFs will help scientists to design the best therapy strategies. In this review, we summarize some of the most important GFs in tissue-engineered menisci, as well as other types of biological stimulation.

scholarly journals Total Meniscus Reconstruction Using a Polymeric Hybrid-Scaffold: Combined with 3D-Printed Biomimetic Framework and Micro-Particle

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1910
Author(s):  
Hun-Jin Jeong ◽  
Se-Won Lee ◽  
Myoung Wha Hong ◽  
Young Yul Kim ◽  
Kyoung Duck Seo ◽  
...  
Keyword(s):  
Shape Matching ◽  
Femoral Condyle ◽  
Immunohistochemical Analysis ◽  
Cartilage Degeneration ◽  
Patient Specific ◽  
Hybrid Scaffold ◽  
Meniscus Tissue ◽  
Cell Source ◽  
3D Printed ◽  
Meniscus Regeneration

The meniscus has poor intrinsic regenerative capability, and its injury inevitably leads to articular cartilage degeneration. Although there are commercialized off-the-shelf alternatives to achieve total meniscus regeneration, each has its own shortcomings such as individualized size matching issues and inappropriate mechanical properties. We manufactured a polycaprolactone-based patient-specific designed framework via a Computed Tomography scan images and 3D-printing technique. Then, we completed the hybrid-scaffold by combining the 3D-printed framework and mixture micro-size composite which consists of polycaprolactone and sodium chloride to create a cell-friendly microenvironment. Based on this hybrid-scaffold with an autograft cell source (fibrochondrocyte), we assessed mechanical and histological results using the rabbit total meniscectomy model. At postoperative 12-week, hybrid-scaffold achieved neo-meniscus tissue formation, and its shape was maintained without rupture or break away from the knee joint. Histological and immunohistochemical analysis results showed obvious ingrowth of the fibroblast-like cells and chondrocyte cells as well as mature lacunae that were embedded in the extracellular matrix. Hybrid-scaffolding resulted in superior shape matching as compared to original meniscus tissue. Histological analysis showed evidence of extensive neo-meniscus cell ingrowth. Additionally, the hybrid-scaffold did not induce osteoarthritis on the femoral condyle surface. The 3D-printed hybrid-scaffold may provide a promising approach that can be applied to those who received total meniscal resection, using patient-specific design and autogenous cell source.

scholarly journals Ocular growth and metabolomics are dependent upon the spectral content of ambient white light

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Raymond P. Najjar ◽  
Juan Manuel Chao De La Barca ◽  
Veluchamy A. Barathi ◽  
Candice Ee Hua Ho ◽  
Jing Zhan Lock ◽  
...  
Keyword(s):  
Critical Role ◽  
Spectral Composition ◽  
Light Therapy ◽  
World Population ◽  
Spectral Content ◽  
Ocular Growth ◽  
Nitric Oxide Metabolism ◽  
Therapy Strategies ◽  
Indoor Lighting ◽  
The Impact

AbstractMyopia results from an excessive axial growth of the eye, causing abnormal projection of remote images in front of the retina. Without adequate interventions, myopia is forecasted to affect 50% of the world population by 2050. Exposure to outdoor light plays a critical role in preventing myopia in children, possibly through the brightness and blue-shifted spectral composition of sunlight, which lacks in artificial indoor lighting. Here, we evaluated the impact of moderate levels of ambient standard white (SW: 233.1 lux, 3900 K) and blue-enriched white (BEW: 223.8 lux, 9700 K) lights on ocular growth and metabolomics in a chicken-model of form-deprivation myopia. Compared to SW light, BEW light decreased aberrant ocular axial elongation and accelerated recovery from form-deprivation. Furthermore, the metabolomic profiles in the vitreous and retinas of recovering form-deprived eyes were distinct from control eyes and were dependent on the spectral content of ambient light. For instance, exposure to BEW light was associated with deep lipid remodeling and metabolic changes related to energy production, cell proliferation, collagen turnover and nitric oxide metabolism. This study provides new insight on light-dependent modulations in ocular growth and metabolomics. If replicable in humans, our findings open new potential avenues for spectrally-tailored light-therapy strategies for myopia.

Computational Simulation of a MEMS-Based Microactuator for Tissue Engineering Applications

2008 ◽  
Author(s):  
Joseph Keyes ◽  
Michael Junkin ◽  
Pak Kin Wong ◽  
Jonathan P. Vande Geest
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Mechanical Stimulation ◽  
Biological Function ◽  
Computational Simulation ◽  
3D Microstructure ◽  
Tissue Replacement ◽  
Engineered Tissue ◽  
Biomechanical Stimulation ◽  
The Relationship

The relationship between the 3D microstructure of tissue-engineered constructs (TECs) and their resulting mechanical and biological function is critical in providing TECs with clinically meaningful mechanical properties in reasonable incubation times. We hypothesize that the next generation of TECs must incorporate a controllable and optimized microstructure (and resulting mechanical properties) if they are to mechanically and biologically mimic tissue function. While the development of a robustly engineered tissue replacement will undoubtedly require simultaneous biochemical and biomechanical stimulation, this paper will focus on the development of a device to impose localized micro-mechanical stimulation.

scholarly journals A Social Enterprise Approach to Empowering Micro, Small and Medium Enterprises (SMEs) in Indonesia

2020 ◽  
Vol 6 (3) ◽  
pp. 50 ◽  
Author(s):  
Irfan Ridwan Maksum ◽  
Amy Yayuk Sri Rahayu ◽  
Dhian Kusumawardhani
Keyword(s):  
Social Welfare ◽  
Social Enterprise ◽  
Small And Medium Enterprises ◽  
Critical Role ◽  
New Approach ◽  
Indonesian Government ◽  
The Social ◽  
Medium Enterprises ◽  
Depth Interviews ◽  
Micro Enterprises

Micro-enterprises play a critical role in the Indonesian economy, in which they supply 99.8% of the country’s employment and account for more than 95% of all enterprises in Indonesia. However, these firms experience many impediments, including a lack of capital, skills, and technology, which creates poor competitiveness. Although the Indonesian government has implemented many policies to deal with these problems, none have been adequate in improving the capacity and productivity of micro, small, and medium enterprises (SMEs). The empowerment program “Iptekda LIPI—Penerapan dan Pemanfaatan Ilmu Pengetahuan dan Teknologi di Daerah Lembaga Ilmu Pengetahuan Indonesia (LIPI)—The Technology for Region Program of the Indonesian Institute of Sciences” proposed a new approach using a social enterprise to solve this issue. This paper analyses the social-enterprise approach of Iptekda LIPI which incorporates market and social welfare to determine the problems experienced by SMEs. The researchers conducted in-depth interviews with the owners of SMEs in West and East Java to explore how this approach may contribute to their businesses and to analyze the challenges of the social enterprise approach in empowering SMEs.

scholarly journals Targeted Disruption of the Wnt Regulator Kremen Induces Limb Defects and High Bone Density

2008 ◽  
Vol 28 (15) ◽  
pp. 4875-4882 ◽  
Author(s):  
Kristina Ellwanger ◽  
Hiroaki Saito ◽  
Philippe Clément-Lacroix ◽  
Nicole Maltry ◽  
Joachim Niedermeyer ◽  
...  
Keyword(s):  
Bone Formation ◽  
Limb Development ◽  
Critical Role ◽  
Functional Interaction ◽  
Triple Mutant ◽  
Targeted Disruption ◽  
Normal Bone ◽  
Physiological Relevance ◽  
High Bone ◽  
High Bone Density

ABSTRACT Kremen1 and Kremen2 (Krm1 and Krm2) are transmembrane coreceptors for Dickkopf1 (Dkk1), an antagonist of Wnt/β-catenin signaling. The physiological relevance of Kremen proteins in mammals as Wnt modulators is unresolved. We generated and characterized Krm mutant mice and found that double mutants show enhanced Wnt signaling accompanied by ectopic postaxial forelimb digits and expanded apical ectodermal ridges. Triple mutant Krm1 −/ − Krm2 −/ − Dkk1 +/ − mice show enhanced growth of ectopic digits, indicating that Dkk1 and Krm genes genetically interact during limb development. Wnt/β-catenin signaling also plays a critical role in bone formation. Single Krm mutants show normal bone formation and bone mass, while double mutants show increased bone volume and bone formation parameters. Our study provides the first genetic evidence for a functional interaction of Kremen proteins with Dkk1 as negative regulators of Wnt/β-catenin signaling and reveals that Kremen proteins are not universally required for Dkk1 function.

scholarly journals Sall4-Gli3 system in early limb progenitors is essential for the development of limb skeletal elements

2015 ◽  
Vol 112 (16) ◽  
pp. 5075-5080 ◽  
Author(s):  
Ryutaro Akiyama ◽  
Hiroko Kawakami ◽  
Julia Wong ◽  
Isao Oishi ◽  
Ryuichi Nishinakamura ◽  
...  
Keyword(s):  
Progenitor Cells ◽  
Sonic Hedgehog ◽  
Limb Development ◽  
Critical Role ◽  
Dependent Manner ◽  
Skeletal Element ◽  
Proximal Development ◽  
Limb Outgrowth ◽  
Common Regulator

Limb skeletal elements originate from the limb progenitor cells, which undergo expansion and patterning to develop each skeletal element. Posterior-distal skeletal elements, such as the ulna/fibula and posterior digits develop in a Sonic hedgehog (Shh)-dependent manner. However, it is poorly understood how anterior-proximal elements, such as the humerus/femur, the radius/tibia and the anterior digits, are developed. Here we show that the zinc finger factors Sall4 and Gli3 cooperate for proper development of the anterior-proximal skeletal elements and also function upstream of Shh-dependent posterior skeletal element development. Conditional inactivation of Sall4 in the mesoderm before limb outgrowth caused severe defects in the anterior-proximal skeletal elements in the hindlimb. We found that Gli3 expression is reduced in Sall4 mutant hindlimbs, but not in forelimbs. This reduction caused posteriorization of nascent hindlimb buds, which is correlated with a loss of anterior digits. In proximal development, Sall4 integrates Gli3 and the Plzf-Hox system, in addition to proliferative expansion of cells in the mesenchymal core of nascent hindlimb buds. Whereas forelimbs developed normally in Sall4 mutants, further genetic analysis identified that the Sall4-Gli3 system is a common regulator of the early limb progenitor cells in both forelimbs and hindlimbs. The Sall4-Gli3 system also functions upstream of the Shh-expressing ZPA and the Fgf8-expressing AER in fore- and hindlimbs. Therefore, our study identified a critical role of the Sall4-Gli3 system at the early steps of limb development for proper development of the appendicular skeletal elements.

scholarly journals Soil Biogeochemical Cycle Couplings Inferred from a Function-Taxon Network

Research ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Bin Ma ◽  
Erinne Stirling ◽  
Yuanhui Liu ◽  
Kankan Zhao ◽  
Jizhong Zhou ◽  
...  
Keyword(s):  
Eastern China ◽  
Critical Role ◽  
Biogeochemical Cycles ◽  
Ecosystem Functions ◽  
Bipartite Network ◽  
Biogeochemical Processes ◽  
Soil Factors ◽  
New Approach ◽  
Latitudinal Transect ◽  
Coupled Biogeochemical Cycles

Soil biogeochemical cycles and their interconnections play a critical role in regulating functions and services of environmental systems. However, the coupling of soil biogeochemical processes with their mediating microbes remains poorly understood. Here, we identified key microbial taxa regulating soil biogeochemical processes by exploring biomarker genes and taxa of contigs assembled from metagenomes of forest soils collected along a latitudinal transect (18° N to 48° N) in eastern China. Among environmental and soil factors, soil pH was a sensitive indicator for functional gene composition and diversity. A function-taxon bipartite network inferred from metagenomic contigs identified the microbial taxa regulating coupled biogeochemical cycles between carbon and phosphorus, nitrogen and sulfur, and nitrogen and iron. Our results provide novel evidence for the coupling of soil biogeochemical cycles, identify key regulating microbes, and demonstrate the efficacy of a new approach to investigate the processes and microbial taxa regulating soil ecosystem functions.

scholarly journals From Doing to Thinking: Developing the Entrepreneurial Mindset through Scaffold Assignments and Self-Regulated Learning Reflection

2019 ◽  
Vol 1 (1) ◽  
pp. 106-121 ◽  
Author(s):  
Lisa Bosman
Keyword(s):  
Value Creation ◽  
Design Thinking ◽  
Experimental Approach ◽  
Learning Experience ◽  
Critical Role ◽  
Value Proposition ◽  
New Approach ◽  
Self Regulated Learning ◽  
Business Model Canvas ◽  
Future Utility

AbstractEngineer, innovators, and designers play a critical role in the economy by addressing pressing problems and creating solutions that are new and innovative. It is a role that involves technical skills but also requires curiosity, an ability to connect pieces of knowledge to discover solutions, and a focus on value creation – which are all characteristic of the entrepreneurial mindset. There are many different design-focused frameworks that can be used to enhance the entrepreneurial mindset; this study focuses on four of them: systems thinking, design thinking, the value proposition canvas, and the business model canvas. The purpose of this paper is to highlight a new approach to developing the entrepreneurial mindset that goes beyond the proverbial “checking boxes” to providing an approach for demonstrating the integration of doing (artifact development) and thinking (reflection). This innovative and experimental approach offers two unique attributes. First, it is a scaffold in that instruction of each of the four modules builds on the other, further enhancing and grounding the learning experience. Second, students are required to continuously reflect on the process. This encourages students to think about learning in a holistic manner, allowing the ability to connect classroom learning with specific current and future utility. The findings suggest that students were able to recognize why the design-focused frameworks and learning activities were important outside of the classroom, particularly in relation to workforce preparation and securing future employment.

scholarly journals 3D Printed Poly(ε-Caprolactone)/Meniscus Extracellular Matrix Composite Scaffold Functionalized With Kartogenin-Releasing PLGA Microspheres for Meniscus Tissue Engineering

2021 ◽  
Vol 9 ◽  
Author(s):  
Hao Li ◽  
Zhiyao Liao ◽  
Zhen Yang ◽  
Cangjian Gao ◽  
Liwei Fu ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Composite Scaffold ◽  
Prolonged Release ◽  
Plga Microspheres ◽  
Cell Vitality ◽  
Meniscal Tissue ◽  
Meniscus Tissue ◽  
Meniscus Regeneration

Meniscus tissue engineering (MTE) aims to fabricate ideal scaffolds to stimulate the microenvironment for recreating the damaged meniscal tissue. Indeed, favorable mechanical properties, suitable biocompatibility, and inherent chondrogenic capability are crucial in MTE. In this study, we present a composite scaffold by 3D printing a poly(ε-caprolactone) (PCL) scaffold as backbone, followed by injection with the meniscus extracellular matrix (MECM), and modification with kartogenin (KGN)-loaded poly(lactic-co-glycolic) acid (PLGA) microsphere (μS), which serves as a drug delivery system. Therefore, we propose a plan to improve meniscus regeneration via KGN released from the 3D porous PCL/MECM scaffold. The final results showed that the hydrophilicity and bioactivity of the resulting PCL/MECM scaffold were remarkably enhanced. In vitro synovium-derived mesenchymal stem cells (SMSCs) experiments suggested that introducing MECM components helped cell adhesion and proliferation and maintained promising ability to induce cell migration. Moreover, KGN-incorporating PLGA microspheres, which were loaded on scaffolds, showed a prolonged release profile and improved the chondrogenic differentiation of SMSCs during the 14-day culture. Particularly, the PCL/MECM-KGN μS seeded by SMSCs showed the highest secretion of total collagen and aggrecan. More importantly, the synergistic effect of the MECM and sustained release of KGN can endow the PCL/MECM-KGN μS scaffolds with not only excellent cell affinity and cell vitality preservation but also chondrogenic activity. Thus, the PCL/MECM-KGN μS scaffolds are expected to have good application prospects in the field of MTE.

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