scholarly journals In VivoMagnetic Resonance Imaging of Type I Collagen Scaffold in Rat: Improving Visualization of Bladder and Subcutaneous Implants

2014 ◽  
Vol 20 (12) ◽  
pp. 964-971 ◽  
Author(s):  
Yi Sun ◽  
Paul Geutjes ◽  
Egbert Oosterwijk ◽  
Arend Heerschap
2014 ◽  
Vol 26 (01) ◽  
pp. 1450005 ◽  
Author(s):  
Tingwei Bao ◽  
Huiming Wang ◽  
Wentao Zhang ◽  
Xuefeng Xia ◽  
Jiabei Zhou ◽  
...  

Purpose: Plasmid loading into scaffolds to enhance sustained release of growth factors is an important focus of regenerative medicine. The aim of this study was to build gene-activated matrices (GAMs) and examine the bone augmentation properties. Methods: Generation 5 polyamidoamine dendrimers (G5 dPAMAM)/plasmid recombinant human bone morphogenetic protein-2 (rhBMP-2) complexes were immobilized into beta-tricalcium phosphate (β-TCP)/type I collagen porous scaffolds. After cultured with rat mesenchymal stem cells (rMSCs), transfection efficiencies were examined. The secretion of rhBMP-2 and alkaline phosphatase (ALP) were detected to evaluate the osteogenic properties. Scanning electron microscopy (SEM) was used to observe attachment and proliferation. Moreover, we applied these GAMs directly into freshly created segmental bone defects in rat femurs, and their osteogenic efficiencies were evaluated. Results: Released plasmid complexes were transfected into stem cells and were expressed, which caused osteogenic differentiations of rat mesenchymal stem cells (rMSCs). SEM analysis showed excellent cell attachment. Bioactivity of plasmid rhBMP-2 was maintained in vivo, and the X-ray observation, histological analysis and immunohistochemistry (IHC) of bone tissue demonstrated that the bone healing in segmental femoral defects was enhanced by implantation of GAMs. Conclusions: Such biomaterials offer therapeutic opportunities in critical-sized bone defects.


2021 ◽  
pp. 2100326
Author(s):  
Ranjeet Ajit Bapat ◽  
Senthil Kumar Muthusamy ◽  
Preena Sidhu ◽  
Mak Kit‐Kay ◽  
Abhishek Parolia ◽  
...  

2014 ◽  
Vol 1585 ◽  
pp. 37-50 ◽  
Author(s):  
Haktan Altinova ◽  
Sven Möllers ◽  
Tobias Führmann ◽  
Ronald Deumens ◽  
Ahmet Bozkurt ◽  
...  

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 306 ◽  
Author(s):  
Haowen Kwan ◽  
Emanuele Chisari ◽  
Wasim S. Khan

Chondral knee defects have a limited ability to be repaired. Current surgical interventions have been unable to regenerate articular cartilage with the mechanical properties of native hyaline cartilage. The use of a scaffold-based approach is a potential solution. Scaffolds are often implanted with cells to stimulate cartilage regeneration, but cell-based therapies are associated with additional regulatory restrictions, an additional surgical procedure for cell harvest, time for cell expansion, and the associated costs. To overcome these disadvantages, cell-free scaffolds can be used in isolation allowing native cells to attach over time. This review discusses the optimal properties of scaffolds used for chondral defects, and the evidence for the use of hydrogel scaffolds and hydrogel–synthetic polymer hybrid scaffolds. Preclinical and clinical studies have shown that cell-free scaffolds can support articular cartilage regeneration and have the potential to treat chondral defects. However, there are very few studies in this area and, despite the many biomaterials tested in cell-based scaffolds, most cell-free studies focused on a specific type I collagen scaffold. Future studies on cell-free scaffolds should adopt the modifications made to cell-based scaffolds and replicate them in the clinical setting. More studies are also needed to understand the underlying mechanism of cell-free scaffolds.


1991 ◽  
Vol 252 ◽  
Author(s):  
David Christiansen ◽  
George Pins ◽  
Ming Che Wang ◽  
Michael G. Dunn ◽  
Frederick H. Silver

ABSTRACTResults of implantation studies in a variety of animal tissue models demonstrate that the rate of biogradation of a collagen scaffold should parallel the rate of wound healing observed in particular anatomic sites. This rapid degradation maximizes tissue regeneration and minimizes encapsulation of the implant. The following paper reviews the effects of crosslinking on the rate of tissue ingrowth and regeneration. In addition, preliminary mechanical data on newly developed soluble type I collagen fibers is presented as a possible advance in the production of high strength collagen based tissue scaffolds.


2021 ◽  
pp. 1-12
Author(s):  
Ruo-Fu Tang ◽  
Xiao-zhong Zhou ◽  
Lie Niu ◽  
Yi-Ying Qi

BACKGROUND: Cartilage tissue lacks the ability to heal. Cartilage tissue engineering using cell-free scaffolds has been increasingly used in recent years. OBJECTIVE: This study describes the use of a type I collagen scaffold combined with WNT5A plasmid to promote chondrocyte proliferation and differentiation in a rabbit osteochondral defect model. METHODS: Type I collagen was extracted and fabricated into a collagen scaffold. To improve gene transfection efficiency, a cationic chitosan derivative N,N,N-trimethyl chitosan chloride (TMC) vector was used. A solution of TMC/WNT5A complexes was adsorbed to the collagen scaffold to prepare a WNT5A scaffold. Osteochondral defects were created in the femoral condyles of rabbits. The rabbits were divided into defect, scaffold, and scaffold with WNT5A groups. At 6 and 12 weeks after creation of the osteochondral defects, samples were collected from all groups for macroscopic observation and gene expression analysis. RESULTS: Samples from the defect group exhibited incomplete cartilage repair, while those from the scaffold and scaffold with WNT5A groups exhibited “preliminary cartilage” covering the defect. Cartilage regeneration was superior in the scaffold with WNT5A group compared to the scaffold group. Safranin O staining revealed more proteoglycans in the scaffold and scaffold with WNT5A groups compared to the defect group. The expression levels of aggrecan, collagen type II, and SOX9 genes were significantly higher in the scaffold with WNT5A group compared to the other two groups. CONCLUSIONS: Type I collagen scaffold showed effective adsorption and guided the three-dimensional arrangement of stem cells. WNT5A plasmid promoted cartilage repair by stimulating the expression of aggrecan, type II collagen, and SOX9 genes and proteins, as well as inhibiting cartilage hypertrophy.


PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248292
Author(s):  
Alexander R. A. Szojka ◽  
Colleen N. Moore ◽  
Yan Liang ◽  
Stephen H. J. Andrews ◽  
Melanie Kunze ◽  
...  

Low oxygen and mechanical loading may play roles in regulating the fibrocartilaginous phenotype of the human inner meniscus, but their combination in engineered tissues remains unstudied. Here, we investigated how continuous low oxygen (“hypoxia”) combined with dynamic compression would affect the fibrocartilaginous “inner meniscus-like” matrix-forming phenotype of human meniscus fibrochondrocytes (MFCs) in a porous type I collagen scaffold. Freshly-seeded MFC scaffolds were cultured for 4 weeks in either 3 or 20% O2 or pre-cultured for 2 weeks in 3% O2 and then dynamically compressed for 2 weeks (10% strain, 1 Hz, 1 h/day, 5 days/week), all with or without TGF-β3 supplementation. TGF-β3 supplementation was found necessary to induce matrix formation by MFCs in the collagen scaffold regardless of oxygen tension and application of the dynamic compression loading regime. Neither hypoxia under static culture nor hypoxia combined with dynamic compression had significant effects on expression of specific protein and mRNA markers for the fibrocartilaginous matrix-forming phenotype. Mechanical properties significantly increased over the two-week loading period but were not different between static and dynamic-loaded tissues after the loading period. These findings indicate that 3% O2 applied immediately after scaffold seeding and dynamic compression to 10% strain do not affect the fibrocartilaginous matrix-forming phenotype of human MFCs in this type I collagen scaffold. It is possible that a delayed hypoxia treatment and an optimized pre-culture period and loading regime combination would have led to different outcomes.


2020 ◽  
Author(s):  
David A. Kukla ◽  
Whitney L. Stoppel ◽  
David L. Kaplan ◽  
Salman R. Khetani

ABSTRACTThe shortage of donor organs for transplantation has prompted the development of alternative implantable human liver tissues; however, the need for a clinically viable liver tissue that can be fabricated using physiologically-relevant primary human hepatocytes (PHHs) is unmet. Purified silk proteins provide desirable features for generating implantable tissues, such as sustainable sourcing from insects/arachnids, biocompatibility, tunable mechanical properties and degradation rates, and low immunogenicity upon implantation; however, the utility of such scaffolds to generate human liver tissues using PHHs remains unclear. Here, we show that the incorporation of type I collagen during the fabrication and/or autoclaving of silk scaffolds was necessary to enable robust PHH attachment/function. Scaffolds with small pores (73 +/- 25 µm) promoted higher PHH functions than large pores (235 +/- 84 µm). Further incorporation of growth-arrested 3T3-J2 fibroblasts into scaffolds enhanced PHH functions up to 5-fold for 5 months in culture, an unprecedented longevity, and functions were better retained than 2D configurations. Lastly, encapsulating PHHs within Matrigel™ while housed in the silk/collagen scaffold led to higher functions than Matrigel or silk/collagen alone. In conclusion, porous silk scaffolds are useful for generating long-term PHH +/- fibroblast tissues which may ultimately find applications in regenerative medicine and drug development.


2020 ◽  
Vol 8 (25) ◽  
pp. 5515-5528
Author(s):  
Hanene Belkahla ◽  
Joana C. Antunes ◽  
Yoann Lalatonne ◽  
Odile Sainte Catherine ◽  
Corinne Illoul ◽  
...  

USPIO–PO–PEG–collagelin nanoparticles specifically target type I collagen and allow fibrosis detection at an early stage by Magnetic Resonance Imaging.


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