scholarly journals Printability Optimization of Gelatin-Alginate Bioinks by Cellulose Nanofiber Modification for Potential Meniscus Bioprinting

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Wenbin Luo ◽  
Zhengyi Song ◽  
Zhonghan Wang ◽  
Zhenguo Wang ◽  
Zuhao Li ◽  
...  

Meniscal injury is more likely to cause a permanent alteration of the biomechanical and biological environment of the knee joint, mainly due to the morphological mismatch and substantial loss of meniscal tissues. Herein, to overcome this challenge, we developed an improved bioink with enhanced printability, while maintaining the biocompatibility of major cellular component of the meniscus, namely fibrochondrocytes. Firstly, cellulose nanofiber (CNF) was mixed with gelatin-alginate thermal-responsive bioinks to improve the printability. Afterward, individual-specific meniscal prototypes based on the 3D reconstruction of MRI data were bioprinted using our bioink. The rheological and printability properties of the bioinks were characterized to select proper bioink content and bioprinting parameters. And then, a series of biological characterizations of the bioprinted samples, such as cell viability, metabolic activity, and extracellular matrix accumulation, were carried out in vitro. The results indicated that superior rheological performance and printability of CNF-modified bioink were achieved, ensuring high-precision bioprinting of specific-designed meniscal prototype when compared with the non-CNF-containing counterparts. Meanwhile, biological tests indicated that fibrochondrocytes encapsulated within the CNF-modified bioink maintained long-term cellular viability as well as acceptable extracellular matrix accumulation. This study demonstrates that the CNF-modified bioink is in favor of the printing fidelity of specific meniscus by improved rheological properties, minimizing the mismatch between artificial meniscal implants and native knee joint tissues, thereby permitting the evolution of clinical therapeutic methods of meniscal reconstruction.

Cells ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 1724
Author(s):  
Gry H. Dihazi ◽  
Marwa Eltoweissy ◽  
Olaf Jahn ◽  
Björn Tampe ◽  
Michael Zeisberg ◽  
...  

The secretome is an important mediator in the permanent process of reciprocity between cells and their environment. Components of secretome are involved in a large number of physiological mechanisms including differentiation, migration, and extracellular matrix modulation. Alteration in secretome composition may therefore trigger cell transformation, inflammation, and diseases. In the kidney, aberrant protein secretion plays a central role in cell activation and transition and in promoting renal fibrosis onset and progression. Using comparative proteomic analyses, we investigated in the present study the impact of cell transition on renal fibroblast cells secretome. Human renal cell lines were stimulated with profibrotic hormones and cytokines, and alterations in secretome were investigated using proteomic approaches. We identified protein signatures specific for the fibrotic phenotype and investigated the impact of modeling secretome proteins on extra cellular matrix accumulation. The secretion of peptidyl-prolyl cis-trans isomerase A (PPIA) was demonstrated to be associated with fibrosis phenotype. We showed that the in-vitro inhibition of PPIA with ciclosporin A (CsA) resulted in downregulation of PPIA and fibronectin (FN1) expression and significantly reduced their secretion. Knockdown studies of PPIA in a three-dimensional (3D) cell culture model significantly impaired the secretion and accumulation of the extracellular matrix (ECM), suggesting a positive therapeutic effect on renal fibrosis progression.


Author(s):  
Angela Seawright ◽  
Altug Ozcelikkale ◽  
J. Craig Dutton ◽  
Bumsoo Han

Cryopreservation can provide long-term storage of various biological tissues, which has significant impact on tissue engineering and regenerative medicine. For successful cryopreservation of tissues, tissue functionality must be maintained including physical properties such as mechanical, optical, and transport properties, as well as cellular viability. Such properties are associated with the extracellular matrix (ECM) microstructure. Thus, the preservation of the ECM microstructure may lead to successful cryopreservation [1,2]. Yet, there is still very little known about changes in the ECM microstructure during freezing/thawing.


2009 ◽  
Vol 297 (1) ◽  
pp. F200-F209 ◽  
Author(s):  
Jin Ji Li ◽  
Sun Ha Lee ◽  
Dong Ki Kim ◽  
Ri Jin ◽  
Dong-Sub Jung ◽  
...  

Recent studies have demonstrated that an inflammatory mechanism contributes to the pathogenesis of diabetic nephropathy (DN). It is also known that colchicine (Col) can prevent various renal injuries via its anti-inflammatory action. However, the effect of colchicine on DN has never been explored. This study was undertaken to elucidate the effect of colchicine on inflammation and extracellular matrix accumulation in DN. In vivo, 64 rats were injected with diluent (C; n = 32) or streptozotocin intraperitoneally (DM, n = 32). Sixteen rats from each group were treated with Col. In vitro, rat mesangial cells and NRK-52E cells were cultured in media with 5.6 mM glucose (NG) or 30 mM glucose (HG) with or without 10−8M Col. Monocyte chemotactic protein-1 (MCP-1) mRNA expression was determined by real-time PCR (RT-PCR), and the levels of MCP-1 in renal tissue and culture media were measured by ELISA. RT-PCR and Western blotting were also performed for intercellular adhesion molecule-1 (ICAM-1) and fibronectin (FN) mRNA and protein expression, respectively, and immunohistochemical staining (IHC) for ICAM-1, FN, and ED-1 with renal tissue. Twenty-four-hour urinary albumin excretion at 6 wk and 3 mo were significantly higher in DM compared with C rats ( P < 0.05), and colchicine treatment significantly reduced albuminuria in DM rats ( P < 0.05). Col significantly inhibited the increase in MCP-1 mRNA expression and protein levels under diabetic conditions both in vivo and in vitro. ICAM-1 and FN expression showed a similar pattern to the expression of MCP-1. IHC revealed that the number of ED-1(+) cells were significantly higher in DM compared with C kidney ( P < 0.005), and this increase was significantly attenuated by Col treatment ( P < 0.01). In conclusion, Col prevents not only inflammatory cell infiltration via inhibition of enhanced MCP-1 and ICAM-1 expression but also ECM accumulation in DN. These findings provide a new perspective on the renoprotective effects of Col in DN.


Author(s):  
Leonie Gronbach ◽  
Philipp Jurmeister ◽  
Monika Schäfer-Korting ◽  
Ulrich Keilholz ◽  
Ingeborg Tinhofer ◽  
...  

3D tumor models clearly outperform 2D cell cultures in recapitulating tissue architecture and drug response. However, their potential in understanding treatment efficacy and resistance development should be better exploited if also long-term effects of treatment could be assessed in vitro. The main disadvantages of the matrices commonly used for in vitro culture are their limited cultivation time and the low comparability with patient-specific matrix properties. Extended cultivation periods are feasible when primary human cells produce the extracellular matrix in situ. Herein, we adapted the hyalograft-3D approach from reconstructed human skin to normal and tumor oral mucosa models and compared the results to bovine collagen-based models. The hyalograft models showed similar morphology and cell proliferation after 7 weeks compared to collagen-based models after 2 weeks of cultivation. Tumor thickness and VEGF expression increased in hyalograft-based tumor models, whereas expression of laminin-332, tenascin C, and hypoxia-inducible factor 1α was lower than in collagen-based models. Taken together, the in situ produced extracellular matrix better confined tumor invasion in the first part of the cultivation period, with continuous tumor proliferation and increasing invasion later on. This proof-of-concept study showed the successful transfer of the hyalograft approach to tumor oral mucosa models and lays the foundation for the assessment of long-term drug treatment effects. Moreover, the use of an animal-derived extracellular matrix is avoided.


Nephron ◽  
2019 ◽  
Vol 142 (4) ◽  
pp. 328-350 ◽  
Author(s):  
Hélène Bon ◽  
Paul Hales ◽  
Simon Lumb ◽  
Gill Holdsworth ◽  
Tim Johnson ◽  
...  

2019 ◽  
Vol 41 (2) ◽  
pp. 306-316 ◽  
Author(s):  
Paul W Holzer ◽  
Alexandre G Lellouch ◽  
Krysta Moulton ◽  
Laurence Zhu ◽  
Zhi Yang Ng ◽  
...  

Abstract Vital, genetically engineered, porcine xenografts represent a promising alternative to human cadaveric allografts (HCA) in the treatment of severe burns. However, their clinical value would be significantly enhanced if preservation and long-term storage—without the loss of cellular viability—were feasible. The objective of this study was to examine the direct impact of cryopreservation and the length of storage on critical in vivo and in vitro parameters, necessary for a successful, potentially equivalent substitute to HCA. In this study, vital, porcine skin grafts, continuously cryopreserved for more than 7 years were compared side-by-side to otherwise identically prepared skin grafts stored for only 15 minutes. Two major histocompatibility complex (MHC)-controlled donor–recipient pairs received surgically created deep-partial wounds and subsequent grafting with split-thickness porcine skin grafts, differentiated only by the duration of storage. Clinical and histological outcomes, as well as quantification of cellular viability via a series of 3-4,5-dimethylthiazol-2-yl]-2,5 diphenyltetrazolium bromide (MTT) assays, were assessed. No statistically significant differences were observed between skin grafts cryopreserved for 15 minutes vs 7 years. Parametric distinctions between xenografts stored for short- vs long-term durations could not be ascertained across independent clinical, histological, or in vitro evaluative methods. The results of this study validate the ability to reliably preserve, store, and retain the essential metabolic activity of porcine tissues after cryopreservation. Plentiful, safe, and readily accessible inventories of vital xenografts represent an advantageous solution to numerous limitations associated with HCA, in the treatment of severe burns.


2017 ◽  
Vol 39 (2) ◽  
pp. 222-229 ◽  
Author(s):  
Hai-fei Liu ◽  
Hong Liu ◽  
Lin-li Lv ◽  
Kun-ling Ma ◽  
Yi Wen ◽  
...  

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