IN VITRO AND IN VIVO DEGRADATION OF A TWISTED SILK FIBROIN–POLY(LACTIC-CO-GLYCOLIC ACID) FIBER COMPOSITE ROPE-LIKE SCAFFOLD AND CHANGES IN ITS MECHANICAL PROPERTIES

2016 ◽  
Vol 16 (04) ◽  
pp. 1650053
Author(s):  
WENYUAN ZHANG ◽  
YADONG YANG ◽  
KEJI ZHANG ◽  
YING LI ◽  
GUOJIAN FANG
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Tissue Engineering ◽  
Mass Loss ◽  
Silk Fibroin ◽  
Glycolic Acid ◽  
Property Loss ◽  
In Vivo Degradation

Natural silk fibroin fiber is slowly degraded, which makes it difficult to be replaced quickly by regenerating tissues of tissue engineering. We used poly(lactic-co-glycolic acid) (PLGA, lactic acid:glycolic acid [Formula: see text] 10:90) fibers to adjust the overall degradation rate of the scaffolds. This study fabricated a three-strand helical composite rope-like scaffold from silk fibroin and PLGA fibers (silk fibroin:PLGA [Formula: see text] 36:64) using a twisting method. In vitro and in vivo degradation experiments were performed over 16 weeks. Results suggest that the in vitro and in vivo degradation tendencies of the scaffold were similar, with mass loss lagging behind mechanical property loss. The speed of degradation in vivo was faster than that in vitro. Mechanical property loss of the scaffold was fast during the first three weeks, when mass loss was slow. Mass loss rate accelerated from weeks 3 to 8. The mass and mechanical properties were relatively stable from 8 to 16 weeks. After 16 weeks of degradation, the scaffold still had considerably strong mechanical properties. The scaffold showed a reasonable and suitable degradation speed with good histocompatibility for ligament tissue engineering.

Porous-conductive chitosan scaffolds for tissue engineering II. in vitro and in vivo degradation

2005 ◽  
Vol 16 (11) ◽  
pp. 1017-1028 ◽  
Author(s):  
Ying Wan ◽  
Aixi Yu ◽  
Hua Wu ◽  
Zhaoxu Wang ◽  
Dijiang Wen
Keyword(s):  
Tissue Engineering ◽  
Chitosan Scaffolds ◽  
In Vivo Degradation

In Vitro and In Vivo Degradation, Mechanical Properties, and Histocompatibility of Weft-Knitted Silk Mesh-Like Grafts

2022 ◽  
Vol 12 (2) ◽  
pp. 411-416
Author(s):  
Liang Tang ◽  
Si-Yu Zhao ◽  
Ya-Dong Yang ◽  
Geng Yang ◽  
Wen-Yuan Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Degradation Rate ◽  
Maximum Load ◽  
Artificial Ligament ◽  
In Vivo Degradation

To investigate the degradation, mechanical properties, and histocompatibility of weft-knitted silk mesh-like grafts, we carried out the In Vitro and In Vivo silk grafts degradation assay. The In Vitro degradation experiment was performed by immersing the silk grafts in simulated body fluid for 1 year, and the results showed that the degradation rate of the silk mesh-like grafts was very slow, and there were few changes in the mechanical properties and quality of the silk mesh-like graft. In Vivo degradation assay was taken by implantation of the silk mesh-like grafts into the subcutaneous muscles of rabbits. At 3, 6, and 12 months postoperation, the rate of mass loss was 19.36%, 31.84%, and 58.77%, respectively, and the maximum load was 63.85%, 34.63%, and 10.76%, respectively of that prior to degradation. The results showed that the degradation rate of the silk graft and the loss of mechanical properties In Vivo were faster than the results obtained in the In Vitro experiments. In addition, there were no significant differences in secretion of serum IL-6 and TNF-α between the experimental and normal rabbits (P >0.05), suggesting no obvious inflammatory reaction. The findings suggest that the weft-knitted silk mesh-like grafts have good mechanical properties, histocompatibility, and In Vivo degradation rate, and therefore represent a candidate material for artificial ligament

scholarly journals Degradation and erosion mechanisms of bioresorbable porous acellular vascular grafts: an in vitro investigation

2017 ◽  
Vol 14 (132) ◽  
pp. 20170102 ◽  
Author(s):  
Piyusha S. Gade ◽  
Keewon Lee ◽  
Blaise N. Pfaff ◽  
Yadong Wang ◽  
Anne M. Robertson
Keyword(s):  
Mechanical Properties ◽  
Mass Loss ◽  
Mechanistic Model ◽  
Vascular Grafts ◽  
Damage Function ◽  
Surface Erosion ◽  
Outer Diameter ◽  
In Vitro Investigation

A fundamental mechanism of in situ tissue regeneration from biodegradable synthetic acellular vascular grafts is the effective interplay between graft degradation, erosion and the production of extracellular matrix. In order to understand this crucial process of graft erosion and degradation, we conducted an in vitro investigation of grafts ( n = 4 at days 1, 4, 7, 10 each) exposed to enzymatic degradation. Herein, we provide constitutive relationships for mass loss and mechanical properties based on much-needed experimental data. Furthermore, we formulate a mathematical model to provide a physics-based framework for understanding graft erosion. A novel finding is that despite their porous nature, grafts lost mass exponentially via surface erosion demonstrating a 20% reduction in outer diameter and no significant change in apparent density. A diffusion based, concentration gradient-driven mechanistic model of mass loss through surface erosion was introduced which can be extended to an in vivo setting through the use of two degradation parameters. Furthermore, notably, mechanical properties of degrading grafts did not scale with mass loss. Thus, we introduced a damage function scaling a neo-Hookean model to describe mechanical properties of the degrading graft; a refinement to existing mass-dependent growth and remodelling (G&R) models. This framework can be used to improve accuracy of well-established G&R theories in biomechanics; tools that predict evolving structure–function relationships of neotissues and guide graft design.

Functional Tissue Engineering: The Role of Biomechanics

2000 ◽  
Vol 122 (6) ◽  
pp. 570-575 ◽  
Author(s):  
David L. Butler ◽  
Steven A. Goldstein ◽  
Farshid Guilak
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Physical Factors ◽  
Cellular Activity ◽  
Biosynthetic Activity ◽  
Functional Tissue Engineering ◽  
Functional Tissue ◽  
Engineered Tissues

“Tissue engineering” uses implanted cells, scaffolds, DNA, protein, and/or protein fragments to replace or repair injured or diseased tissues and organs. Despite its early success, tissue engineers have faced challenges in repairing or replacing tissues that serve a predominantly biomechanical function. An evolving discipline called “functional tissue engineering” (FTE) seeks to address these challenges. In this paper, the authors present principles of functional tissue engineering that should be addressed when engineering repairs and replacements for load-bearing structures. First, in vivo stress/strain histories need to be measured for a variety of activities. These in vivo data provide mechanical thresholds that tissue repairs/replacements will likely encounter after surgery. Second, the mechanical properties of the native tissues must be established for subfailure and failure conditions. These “baseline data” provide parameters within the expected thresholds for different in vivo activities and beyond these levels if safety factors are to be incorporated. Third, a subset of these mechanical properties must be selected and prioritized. This subset is important, given that the mechanical properties of the designs are not expected to completely duplicate the properties of the native tissues. Fourth, standards must be set when evaluating the repairs/replacements after surgery so as to determine, “how good is good enough?” Some aspects of the repair outcome may be inferior, but other mechanical characteristics of the repairs and replacements might be suitable. New and improved methods must also be developed for assessing the function of engineered tissues. Fifth, the effects of physical factors on cellular activity must be determined in engineered tissues. Knowing these signals may shorten the iterations required to replace a tissue successfully and direct cellular activity and phenotype toward a desired end goal. Finally, to effect a better repair outcome, cell-matrix implants may benefit from being mechanically stimulated using in vitro “bioreactors” prior to implantation. Increasing evidence suggests that mechanical stress, as well as other physical factors, may significantly increase the biosynthetic activity of cells in bioartificial matrices. Incorporating each of these principles of functional tissue engineering should result in safer and more efficacious repairs and replacements for the surgeon and patient. [S0148-0731(00)00206-5]

A Poly(lactic-co-glycolic acid) Knitted Scaffold for Tendon Tissue Engineering: An In Vitro and In Vivo Study

2010 ◽  
Vol 21 (13) ◽  
pp. 1737-1760 ◽  
Author(s):  
Cédryck Vaquette ◽  
Saïd Slimani ◽  
Cyril J. F. Kahn ◽  
Nguyen Tran ◽  
Rachid Rahouadj ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Glycolic Acid ◽  
In Vivo Study ◽  
Tendon Tissue ◽  
Tendon Tissue Engineering

A Strain Energy-Based Constitutive Model for Continuous-Fiber Tissue Engineered Valved Conduit Tissue

2011 ◽  
Author(s):  
Chad E. Eckert ◽  
Michael S. Sacks
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Strain Energy ◽  
Growth And Remodeling ◽  
Continuous Fiber ◽  
Analog System ◽  
Mechanical Quality ◽  
Valved Conduit

Understanding growth and remodeling of extracelluar matrix (ECM) embedded in a scaffold phase is crucial for improving tissue engineering efforts, especially within the context of a mechanically-demanding enviroment to which engineered heart valve tissues (EHVT) are subjected. Our previous modeling efforts at short in vitro timepoints (one to three weeks) [1] illustrated the strong dependency of ECM-scaffold composite mechanical properties on that of the existing continuous scaffold phase. In this work, we build on these efforts by developing a generalized, large-deformation continuum-based model for short timepoint in vitro/in vivo environments and validating it using a ECM-analog system to simulate remodeling tissue. It is our intent to estimate the ECM mechanical quality from the measured scaffold-ECM composite.

scholarly journals Engineered Hypopharynx from Coculture of Epithelial Cells and Fibroblasts Using Poly(ester urethane) as Substratum

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Zhisen Shen ◽  
Jingjing Chen ◽  
Cheng Kang ◽  
Changfeng Gong ◽  
Yabin Zhu
Keyword(s):  
Tissue Engineering ◽  
Epithelial Cells ◽  
Silk Fibroin ◽  
Porous Scaffold ◽  
Engineering Research ◽  
Polymeric Scaffolds ◽  
Cell Tissue ◽  
Silkworm Cocoon

Porous polymeric scaffolds have been much investigated and applied in the field of tissue engineering research. Poly(ester urethane) (PEU) scaffolds, comprising pores of 1–20 μm in diameter on one surface and ≥200 μm on the opposite surface and in bulk, were fabricated using phase separation method for hypopharyngeal tissue engineering. The scaffolds were grafted with silk fibroin (SF) generated from natural silkworm cocoon to enhance the scaffold’s hydrophilicity and further improve cytocompatibility to both primary epithelial cells (ECs) and fibroblasts of human hypopharynx tissue. Coculture of ECs and fibroblasts was conducted on the SF-grafted PEU scaffold (PEU-SF) to evaluate itsin vitrocytocompatibility. After co-culture for 14 days, ECs were lined on the scaffold surface while fibroblasts were distributed in scaffold bulk. The results ofin vivoinvestigation showed that PEU porous scaffold possessed good biocompatibility after it was grafted by silk fibroin. SF grafting improved the cell/tissue infiltration into scaffold bulk. Thus, PEU-SF porous scaffold is expected to be a good candidate to support the hypopharynx regeneration.

scholarly journals Biomechanical study of cellulose scaffolds for bone tissue engineering in vivo and in vitro.

2021 ◽  
Author(s):  
Maxime Leblanc Latour ◽  
Maryam Tarar ◽  
Ryan J. Hickey ◽  
Charles M. Cuerrier ◽  
Isabelle Catelas ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Bone Tissue Engineering ◽  
Osteogenic Differentiation ◽  
Bone Tissue ◽  
Cell Invasion ◽  
Osteogenic Potential ◽  
Load Bearing

Plant-derived cellulose biomaterials have recently been utilized in several tissue engineering applications. These naturally-derived cellulose scaffolds have been shown to be highly biocompatible in vivo, possess structural features of relevance to several tissues, and support mammalian cell invasion and proliferation. Recent work utilizing decellularized apple hypanthium tissue has shown that it possesses a pore size similar to trabecular bone and can successfully host osteogenic differentiation. In the present study, we further examined the potential of apple-derived cellulose scaffolds for bone tissue engineering (BTE) and analyzed their mechanical properties in vitro and in vivo. MC3T3-E1 pre-osteoblasts were seeded in cellulose scaffolds. Following chemically-induced osteogenic differentiation, scaffolds were evaluated for mineralization and for their mechanical properties. Alkaline phosphatase and Alizarin Red staining confirmed the osteogenic potential of the scaffolds. Histological analysis of the constructs revealed cell invasion and mineralization throughout the constructs. Furthermore, scanning electron microscopy demonstrated the presence of mineral aggregates on the scaffolds after culture in differentiation medium, and energy-dispersive spectroscopy confirmed the presence of phosphate and calcium. However, although the Young′s modulus significantly increased after cell differentiation, it remained lower than that of healthy bone tissue. Interestingly, mechanical assessment of acellular scaffolds implanted in rat calvaria defects for 8 weeks revealed that the force required to push out the scaffolds from the surrounding bone was similar to that of native calvarial bone. In addition, cell infiltration and extracellular matrix deposition were visible within the implanted scaffolds. Overall, our results confirm that plant-derived cellulose is a promising candidate for BTE applications. However, the discrepancy in mechanical properties between the mineralized scaffolds and healthy bone tissue may limit their use to low load-bearing applications. Further structural re-engineering and optimization to improve the mechanical properties may be required for load-bearing applications.

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