scholarly journals Functional Epithelium Remodeling in Response to Applied Stress under In Vitro Conditions

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Ivana Pajic-Lijakovic ◽  
Milan Milivojevic
Keyword(s):  
Tissue Engineering ◽  
Applied Stress ◽  
Volume Fraction ◽  
Volume Ratio ◽  
Cell Groups ◽  
Long Time ◽  
Analogous Model ◽  
Eyring Model ◽  
Migrating Cells

Mathematical modeling is often used in tissue engineering in order to overcome one of its major challenges: transformation of complex biological and rheological behaviors of cells and tissue in a mathematically predictive and physically manipulative engineering process. The successive accomplishment of this task will greatly help in quantifying and optimizing clinical application of the tissue engineering products. One of the problems emerging in this area is the relation between resting and migrating cell groups, as well as between different configurations of migrating cells and viscoelasticity. A deeper comprehension of the relation between various configurations of migrating cells and viscoelasticity at the supracellular level represents the prerequisite for optimization of the performance of the artificial epithelium. Since resting and migrating cell groups have a considerable difference in stiffness, a change in their mutual volume ratio and distribution may affect the viscoelasticity of multicellular surfaces. If those cell groups are treated as different phases, then an analogous model may be applied to represent such systems. In this work, a two-step Eyring model is developed in order to demonstrate the main mechanical and biochemical factors that influence configurations of migrating cells. This model could be also used for considering the long-time cell rearrangement under various types of applied stress. The results of this theoretical analysis point out the cause-consequence relationship between the configuration of migrating cells and rheological behavior of multicellular surfaces. Configuration of migrating cells is influenced by mechanical and biochemical perturbations, difficult to measure experimentally, which lead to uncorrelated motility. Uncorrelated motility results in (1) decrease of the volume fraction of migrating cells, (2) change of their configuration, and (3) softening of multicellular surfaces.

Preparation of Electrospun PLA Nanofiber Scaffold and the Evaluation In Vitro

2005 ◽  
Vol 288-289 ◽  
pp. 139-142 ◽  
Author(s):  
Xian Tao Wen ◽  
Hong Song Fan ◽  
Yan Fei Tan ◽  
H.D. Cao ◽  
H. Li ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Soft Tissue ◽  
High Surface ◽  
Volume Ratio ◽  
Electrospinning Process ◽  
High Porosity ◽  
Electrospun Scaffold ◽  
Nanofiber Scaffold ◽  
Soft Tissue Engineering

A electrospinning process to prepare soft tissue engineering scaffold was introduced in this study. This kind of scaffold was composed with ultrathin fiber and characterized with high porosity, well-interconnected pores and high surface-to-volume ratio. Biodegradable polylaticacid (PLA) was used to spin the scaffold and the scaffold was evaluated in vitro by analysis the microscopic structure, porosity, mechanical property, especially cytocompatibility. The results indicated that the electrospun PLA scaffold showed good cytocompatibility and the tensile property of electrospun scaffold was similar to human’s soft tissue. It could be expected that the electrospun scaffold would be potential in soft tissue engineering or soft tissue repair.

scholarly journals Basic Potential of Carbon Nanotubes in Tissue Engineering Applications

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Hisao Haniu ◽  
Naoto Saito ◽  
Yoshikazu Matsuda ◽  
Tamotsu Tsukahara ◽  
Yuki Usui ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Tissue Engineering ◽  
High Surface ◽  
High Surface Area ◽  
Volume Ratio ◽  
Medical Application ◽  
Mechanical And Thermal Properties ◽  
Biological Responses

Carbon nanotubes (CNTs) are attracting interest in various fields of science because they possess a high surface area-to-volume ratio and excellent electronic, mechanical, and thermal properties. Various medical applications of CNTs are expected, and the properties of CNTs have been greatly improved for use in biomaterials. However, the safety of CNTs remains unclear, which impedes their medical application. Our group is evaluating the biological responses of multiwall CNTs (MWCNTs)in vivoandin vitrofor the promotion of tissue regeneration as safe scaffold materials. We recently showed that intracellular accumulation is important for the cytotoxicity of CNTs, and we reported the active physiological functions CNTs in cells. In this review, we describe the effects of CNTsin vivoandin vitroobserved by our group from the standpoint of tissue engineering, and we introduce the findings of other research groups.

Study of Electrospun PLLACL Nanofibrous Mats for Drug Delivery System

2009 ◽  
Vol 610-613 ◽  
pp. 1319-1322 ◽  
Author(s):  
Shui Ping Liu ◽  
Xiao Qiang Li ◽  
Yan Su ◽  
Lian Jiang Tan ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Tissue Engineering ◽  
Drug Delivery System ◽  
Wound Dressing ◽  
Coaxial Electrospinning ◽  
Release Behavior ◽  
The Core ◽  
Vis Spectroscopy ◽  
Long Time

In the present study an innovative tissue engineering scaffold was developed which can be used on wound dressing with a controllable drug-releasing capability. By coaxial electrospinning a coaxial nanofibrous mats were obtained which was made from Poly(L-lactid-co-ε-caprolactone) (PLLACL) and Tetracycline Hydrochloride (TCH), with P(LLA-CL) as the shell and TCH as the core. The TCH release behavior of the coaxial nanofibrous mats was measured by ultraviolet-visible (UV-vis) spectroscopy in vitro environment of 37°C for a maximum 180 hours. To compare with the method of mix electrospinning, TCH without any other material could encapsulated in P(LLA-CL) nanofibers very well and released for a long time.

scholarly journals Poly(lactide- co -glycolide) porous scaffolds for tissue engineering and regenerative medicine

2012 ◽  
Vol 2 (3) ◽  
pp. 366-377 ◽  
Author(s):  
Zhen Pan ◽  
Jiandong Ding
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Regenerative Medicine ◽  
Porous Scaffolds ◽  
Plga Scaffold ◽  
Degradation Rates ◽  
Long Time ◽  
Facile Fabrication

Porous scaffolds fabricated from biocompatible and biodegradable polymers play vital roles in tissue engineering and regenerative medicine. Among various scaffold matrix materials, poly(lactide- co -glycolide) (PLGA) is a very popular and an important biodegradable polyester owing to its tunable degradation rates, good mechanical properties and processibility, etc. This review highlights the progress on PLGA scaffolds. In the latest decade, some facile fabrication approaches at room temperature were put forward; more appropriate pore structures were designed and achieved; the mechanical properties were investigated both for dry and wet scaffolds; a long time biodegradation of the PLGA scaffold was observed and a three-stage model was established; even the effects of pore size and porosity on in vitro biodegradation were revealed; the PLGA scaffolds have also been implanted into animals, and some tissues have been regenerated in vivo after loading cells including stem cells.

scholarly journals Identifying chondrogenesis strategies for tissue engineering of articular cartilage

2019 ◽  
Vol 10 ◽  
pp. 204173141984243 ◽  
Author(s):  
Michael J Chen ◽  
Jonathan P Whiteley ◽  
Colin P Please ◽  
Franziska Ehlicke ◽  
Sarah L Waters ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Articular Cartilage ◽  
Chondrogenic Differentiation ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β ◽  
Native Cartilage ◽  
Long Time ◽  
Cartilage Cells ◽  
Tissue Construct

A key step in the tissue engineering of articular cartilage is the chondrogenic differentiation of mesenchymal stem cells (MSCs) into chondrocytes (native cartilage cells). Chondrogenesis is regulated by transforming growth factor- β (TGF- β), a short-lived cytokine whose effect is prolonged by storage in the extracellular matrix. Tissue engineering applications aim to maximise the yield of differentiated MSCs. Recent experiments involve seeding a hydrogel construct with a layer of MSCs lying below a layer of chondrocytes, stimulating the seeded cells in the construct from above with exogenous TGF- β and then culturing it in vitro. To investigate the efficacy of this strategy, we develop a mathematical model to describe the interactions between MSCs, chondrocytes and TGF- β. Using this model, we investigate the effect of varying the initial concentration of TGF- β, the initial densities of the MSCs and chondrocytes, and the relative depths of the two layers on the long-time composition of the tissue construct.

Bi-layered electrospun nanofibrous polyurethane-gelatin scaffold with targeted heparin release profiles for tissue engineering applications

2017 ◽  
Vol 37 (9) ◽  
pp. 933-941 ◽  
Author(s):  
Mohammad Mahdi Safikhani ◽  
Ali Zamanian ◽  
Farnaz Ghorbani ◽  
Azadeh Asefnejad ◽  
Mostafa Shahrezaee
Keyword(s):  
Tissue Engineering ◽  
High Surface ◽  
High Surface Area ◽  
Three Dimensional ◽  
Coagulation Factor ◽  
Volume Ratio ◽  
Fibroblast Cell ◽  
Porous Scaffolds ◽  
Nanofibrous Scaffolds

Abstract Tissue engineering is a biotechnology that is used to develop biological substitutes to restore, maintain, or improve functions. Thus, the porous scaffolds are used to accommodate cells in tissue engineering. In this research, three dimensional (3D) bi-layered polyurethane (PU)-gelatin nanofibrous scaffolds were prepared by the electrospinning method, after which the capability of the released heparin as an anti-coagulation factor was evaluated. Electrospinning has been extensively investigated for the preparation of fibers that exhibit a high surface area to volume ratio. Results showed that scanning electron microscopy (SEM) micrographs exhibited a smooth surface as well as a highly porous and bead-free structure, in which fibers were distributed in the range of 100–600 nm. The modulus and ultimate tensile strength (UTS) decreased and increased, respectively, after crosslinking the reaction of polymers. This process also reduced swelling ratio, the hydrolytic biodegradation rate, and the release rate as a function of time. Moreover, an in vitro assay demonstrated that 3D nanofibrous scaffolds supported L929 fibroblast cell viability and that cells adhered and spread on the fibers. Based on the obtained results, the heparin-loaded electrospinning nanofibrous scaffolds have initial physicochemical and mechanical properties to protect neo-tissue formation.

Decellularized bone extracellular matrix in skeletal tissue engineering

2020 ◽  
Vol 48 (3) ◽  
pp. 755-764
Author(s):  
Benjamin B. Rothrauff ◽  
Rocky S. Tuan
Keyword(s):  
Tissue Engineering ◽  
Bone Regeneration ◽  
Tissue Regeneration ◽  
Animal Studies ◽  
Tumor Resection ◽  
Regenerative Capacity ◽  
Skeletal Tissue ◽  
Large Bone

Bone possesses an intrinsic regenerative capacity, which can be compromised by aging, disease, trauma, and iatrogenesis (e.g. tumor resection, pharmacological). At present, autografts and allografts are the principal biological treatments available to replace large bone segments, but both entail several limitations that reduce wider use and consistent success. The use of decellularized extracellular matrices (ECM), often derived from xenogeneic sources, has been shown to favorably influence the immune response to injury and promote site-appropriate tissue regeneration. Decellularized bone ECM (dbECM), utilized in several forms — whole organ, particles, hydrogels — has shown promise in both in vitro and in vivo animal studies to promote osteogenic differentiation of stem/progenitor cells and enhance bone regeneration. However, dbECM has yet to be investigated in clinical studies, which are needed to determine the relative efficacy of this emerging biomaterial as compared with established treatments. This mini-review highlights the recent exploration of dbECM as a biomaterial for skeletal tissue engineering and considers modifications on its future use to more consistently promote bone regeneration.

Bioreaktoren für Knochen-Tissue-Engineering

2013 ◽  
Vol 22 (03) ◽  
pp. 188-195 ◽  
Author(s):  
H.-H. Hsu ◽  
C. Goepfert ◽  
R. Pörtner
Keyword(s):  
Tissue Engineering

ZusammenfassungZur medizinischen Behandlung großer Knochendefekte oder Verletzungen werden als Alternative zu etablierten Behandlungs-methoden neue Konzepte des Tissue Engineering (TE) diskutiert. Beim Knochen-TE ist es das Ziel, eine mit Zellen besiedelte drei-dimensionale (3D), biologisch abbaubare Struktur am Ort der Verletzung zu implantieren. Techniken für die organotypische Kultivierung von Knochenzellen in vitro beruhen auf der Kultivierung von Gewebezellen in Bioreaktoren in einem definierten Kultur-medium auf porösen Matrizes (Scaffolds), um ein gewebeähnliches Wachstum in 3D-Strukturen zu ermöglichen. Ein wichtiger Faktor für die erfolgreiche 3D-Kultur ist die Schaffung adäquater Strömungsbedingungen, die wiederum Einfluss auf die biochemischen und biophysikalischen (z. B. mechanische) Reize haben, denen die Zellen ausgesetzt sind. Hier müssen neben Schereffekten auch Stofftransportlimitierungen berücksichtigt werden. Der Beitrag fasst den aktuellen Stand bei der Entwicklung von Bioreaktoren für die Generierung von Knochenersatzmaterialien zusammen.

In vitro- / in vivo- Untersuchungen zur Biokompatibilität und Bioresorption amorpher Kieselgelfaser für das Tissue engineering humaner Knorpelgewebe

2004 ◽  
Vol 83 (02) ◽  
Author(s):  
A Haisch ◽  
A Evers ◽  
K Jöhrens-Leder ◽  
S Jovanovic ◽  
B Sedlmaier ◽  
...  
Keyword(s):  
Tissue Engineering
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