Microscopic Analysis of Porous Biodegradable Scaffolds for Tissue Engineering

2000 ◽  
Vol 6 (S2) ◽  
pp. 988-989
Author(s):  
F. Buevich ◽  
S. Pulapura ◽  
J. Kohn
Keyword(s):  
Tissue Regeneration ◽  
Combinatorial Library ◽  
Three Dimensional ◽  
Microscopic Analysis ◽  
Porous Scaffolds ◽  
Biodegradable Scaffolds ◽  
Condensation Polymers ◽  
Scaffold Architecture ◽  
Useful Lifetime

Introduction: There is considerable interest in the use of three-dimensional porous scaffolds for tissue regeneration. The presence of an interconnected framework of pores with large surface area facilitates the formation of extracellular matrix and permits cellular ingrowth into implanted structures. For scaffolds to be useful for tissue regeneration, they must maintain good dimensional stability during the lifetime of the implant. While the initial scaffold architecture is often well characterized, a systematic study of the influence of incubation on the scaffold architecture is critical to ensure that the scaffolds retain their interconnected network of pores during their useful lifetime. Herein, we report on the evaluation of the architecture of polyarylate scaffolds and their stability under in vitro conditions using scanning electron microscopy (SEM).The polymers used in this study were selected from a library of degradable polyarylates. This library is the first reported combinatorial library of biodegradable condensation polymers.

scholarly journals Polycaprolactone Scaffolds Fabricated via Bioextrusion for Tissue Engineering Applications

2009 ◽  
Vol 2009 ◽  
pp. 1-9 ◽  
Author(s):  
Marco Domingos ◽  
Dinuccio Dinucci ◽  
Stefania Cometa ◽  
Michele Alderighi ◽  
Paulo Jorge Bártolo ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Tissue Regeneration ◽  
Low Cost ◽  
Biological Evaluation ◽  
Porous Scaffolds ◽  
3D Scaffolds ◽  
Cost System ◽  
Biodegradable Scaffolds ◽  
Donor Cells

The most promising approach in Tissue Engineering involves the seeding of porous, biocompatible/biodegradable scaffolds, with donor cells to promote tissue regeneration. Additive biomanufacturing processes are increasingly recognized as ideal techniques to produce 3D structures with optimal pore size and spatial distribution, providing an adequate mechanical support for tissue regeneration while shaping in-growing tissues. This paper presents a novel extrusion-based system to produce 3D scaffolds with controlled internal/external geometry for TE applications.The BioExtruder is a low-cost system that uses a proper fabrication code based on the ISO programming language enabling the fabrication of multimaterial scaffolds. Poly(ε-caprolactone) was the material chosen to produce porous scaffolds, made by layers of directionally aligned microfilaments. Chemical, morphological, and in vitro biological evaluation performed on the polymeric constructs revealed a high potential of the BioExtruder to produce 3D scaffolds with regular and reproducible macropore architecture, without inducing relevant chemical and biocompatibility alterations of the material.

In Vitro Degradation of β-TCP/PLLA Scaffolds with Different Proportions of β-TCP

2007 ◽  
Vol 336-338 ◽  
pp. 1545-1548
Author(s):  
Lin Luo ◽  
Guang Fu Yin ◽  
Yun Zhang ◽  
Ya Dong Yao ◽  
Wei Zhong Yang ◽  
...  
Keyword(s):  
Degradation Rate ◽  
Porous Scaffolds ◽  
Carbonate Apatite ◽  
Tissue Formation ◽  
Cellular Attachment ◽  
Biodegradable Scaffolds ◽  
Scaffold Structure ◽  
Mechanical Strengths

Porous biodegradable scaffolds are widely used in bone tissue engineering to provide temporary templates for cellular attachment and matrix synthesis. Ideally, the degradation rate in vivo may be similar or slightly less than that of tissue formation, allowing for the maintenance of the scaffold structure and the mechanical support during early stages of tissue formation. Eventually, the 3-D spaces occupied by the porous scaffolds will be replaced by newly formed tissue. In this work, β-tricalcium phosphate/Poly-L lactide (β-TCP/PLLA) scaffolds with different proportions of β-TCP to PLLA were investigated. The effects of β-TCP proportions on degradation rate and mechanical strengths of the scaffolds were evaluated in simulated body fluid (SBF) at 37°C up to 42 days. Results show that: different proportions of β-TCP to PLLA have significant influence on degradation behaviors of the scaffolds, and mechanical strengths of the scaffolds with weight proportion of β-TCP to PLLA being 2 to 1 are much higher than those of the others during the degradation period. And in this period, the scaffolds biodegrade slowly, and Hydroxyl Carbonate Apatite (HCA) forms in the surface of the material.

scholarly journals Porous Geometry Guided Micro-mechanical Environment Within Scaffolds for Cell Mechanobiology Study in Bone Tissue Engineering

2021 ◽  
Vol 9 ◽  
Author(s):  
Feihu Zhao ◽  
Yi Xiong ◽  
Keita Ito ◽  
Bert van Rietbergen ◽  
Sandra Hofmann
Keyword(s):  
Porous Scaffold ◽  
Mechanical Strain ◽  
Three Dimensional ◽  
Pore Geometry ◽  
Cell Physiology ◽  
Porous Scaffolds ◽  
Mechanical Environment ◽  
Functional Features ◽  
Future Work

Mechanobiology research is for understanding the role of mechanics in cell physiology and pathology. It will have implications for studying bone physiology and pathology and to guide the strategy for regenerating both the structural and functional features of bone. Mechanobiological studies in vitro apply a dynamic micro-mechanical environment to cells via bioreactors. Porous scaffolds are commonly used for housing the cells in a three-dimensional (3D) culturing environment. Such scaffolds usually have different pore geometries (e.g. with different pore shapes, pore dimensions and porosities). These pore geometries can affect the internal micro-mechanical environment that the cells experience when loaded in the bioreactor. Therefore, to adjust the applied micro-mechanical environment on cells, researchers can tune either the applied load and/or the design of the scaffold pore geometries. This review will provide information on how the micro-mechanical environment (e.g. fluid-induced wall shear stress and mechanical strain) is affected by various scaffold pore geometries within different bioreactors. It shall allow researchers to estimate/quantify the micro-mechanical environment according to the already known pore geometry information, or to find a suitable pore geometry according to the desirable micro-mechanical environment to be applied. Finally, as future work, artificial intelligent – assisted techniques, which can achieve an automatic design of solid porous scaffold geometry for tuning/optimising the micro-mechanical environment are suggested.

scholarly journals COMPARATIVE ANALYSIS OF THREE-DIMENSIONAL NANOSTRUCTURE OF POROUS BIOCOMPATIBLE SCAFFOLDS MADE OF RECOMBINANT SPIDROIN AND SILK FIBROIN FOR REGENERATIVE MEDICINE

2015 ◽  
Vol 17 (2) ◽  
pp. 37-44 ◽  
Author(s):  
O. I. Agapova ◽  
A. E. Efimov ◽  
M. M. Moisenovich ◽  
V. G. Bogush ◽  
I. I. Agapov
Keyword(s):  
Volume Fraction ◽  
Three Dimensional ◽  
Scanning Probe ◽  
Porous Scaffolds ◽  
Volume Porosity ◽  
Integral Density ◽  
Regenerative Activity ◽  
Calculated Volume ◽  
Recombinant Spidroin

Aim.To perform a comparison of three-dimensional nanostructure of porous biocompatible scaffolds made of fibroinBombix moriand recombinant spidroin rS1/9.Materials and methods.Three-dimensional porous scaffolds were produced by salt leaching technique. The comparison of biological characteristics of the scaffolds shows that adhesion and proliferation of mouse fibroblastsin vitroon these two types of scaffolds do not differ significantly. Comparative experimentsin vivoshow that regeneration of bone tissue of rats is faster with implantation of recombinant spidroin scaffolds. Three-dimensional nanostructure of scaffolds and interconnectivity of nanopores were studied with scanning probe nanotomography (SPNT) to explain higher regenerative activity of spidroin-based scaffolds.Results.Significant differences were detected in the integral density and volume of pores: the integral density of nanopores detected on 2D AFM images is 46 μm–2    and calculated volume porosity is 24% in rS1/9-based scaffolds; in fibroin-based three-dimensional structures density of nanopores and calculated volume porosity were 2.4 μm–2  and 0.5%, respectively. Three-dimensional reconstruction system of nanopores and clusters of interconnected nanopores in rS1/9-based scaffolds showed that volume fraction of pores interconnected in percolation clusters is 35.3% of the total pore volume or 8.4% of the total scaffold volume.Conclusion.Scanning probe nanotomography method allows obtaining unique information about topology of micro – and nanopore systems of artificial biostructures. High regenerative activity of rS1/9-based scaffolds can be explained by higher nanoporosity of the scaffolds.

scholarly journals Additive Manufacturing of Biopolymers for Tissue Engineering and Regenerative Medicine: An Overview, Potential Applications, Advancements, and Trends

2021 ◽  
Vol 2021 ◽  
pp. 1-20 ◽  
Author(s):  
Dhinakaran Veeman ◽  
M. Swapna Sai ◽  
P. Sureshkumar ◽  
T. Jagadeesha ◽  
L. Natrayan ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Regenerative Medicine ◽  
Tissue Regeneration ◽  
Three Dimensional ◽  
Porous Scaffolds ◽  
Wide Range ◽  
Potential Applications ◽  
Pharmaceutical Industries

As a technique of producing fabric engineering scaffolds, three-dimensional (3D) printing has tremendous possibilities. 3D printing applications are restricted to a wide range of biomaterials in the field of regenerative medicine and tissue engineering. Due to their biocompatibility, bioactiveness, and biodegradability, biopolymers such as collagen, alginate, silk fibroin, chitosan, alginate, cellulose, and starch are used in a variety of fields, including the food, biomedical, regeneration, agriculture, packaging, and pharmaceutical industries. The benefits of producing 3D-printed scaffolds are many, including the capacity to produce complicated geometries, porosity, and multicell coculture and to take growth factors into account. In particular, the additional production of biopolymers offers new options to produce 3D structures and materials with specialised patterns and properties. In the realm of tissue engineering and regenerative medicine (TERM), important progress has been accomplished; now, several state-of-the-art techniques are used to produce porous scaffolds for organ or tissue regeneration to be suited for tissue technology. Natural biopolymeric materials are often better suited for designing and manufacturing healing equipment than temporary implants and tissue regeneration materials owing to its appropriate properties and biocompatibility. The review focuses on the additive manufacturing of biopolymers with significant changes, advancements, trends, and developments in regenerative medicine and tissue engineering with potential applications.

scholarly journals Subaxolemmal cytoskeleton in squid giant axon. II. Morphological identification of microtubule- and microfilament-associated domains of axolemma.

1986 ◽  
Vol 102 (5) ◽  
pp. 1710-1725 ◽  
Author(s):  
S Tsukita ◽  
S Tsukita ◽  
T Kobayashi ◽  
G Matsumoto
Keyword(s):  
Electron Microscopy ◽  
Three Dimensional ◽  
Preceding Paper ◽  
Microscopic Analysis ◽  
Giant Axon ◽  
Squid Giant Axon ◽  
Molecular Organization ◽  
Fixation Method ◽  
Morphological Identification

In the preceding paper (Kobayashi, T., S. Tsukita, S. Tsukita, Y. Yamamoto, and G. Matsumoto, 1986, J. Cell Biol., 102:1710-1725), we demonstrated biochemically that the subaxolemmal cytoskeleton of the squid giant axon was highly specialized and mainly composed of tubulin, actin, axolinin, and a 255-kD protein. In this paper, we analyzed morphologically the molecular organization of the subaxolemmal cytoskeleton in situ. For thin section electron microscopy, the subaxolemmal cytoskeleton was chemically fixed by the intraaxonal perfusion of the fixative containing tannic acid. With this fixation method, the ultrastructural integrity was well preserved. For freeze-etch replica electron microscopy, the intraaxonally perfused axon was opened and rapidly frozen by touching its inner surface against a cooled copper block (4 degrees K), thus permitting the direct stereoscopic observation of the cytoplasmic surface of the axolemma. Using these techniques, it became clear that the major constituents of the subaxolemmal cytoskeleton were microfilaments and microtubules. The microfilaments were observed to be associated with the axolemma through a specialized meshwork of thin strands, forming spot-like clusters just beneath the axolemma. These filaments were decorated with heavy meromyosin showing a characteristic arrowhead appearance. The microtubules were seen to run parallel to the axolemma and embedded in the fine three-dimensional meshwork of thin strands. In vitro observations of the aggregates of axolinin and immunoelectron microscopic analysis showed that this fine meshwork around microtubules mainly consisted of axolinin. Some microtubules grazed along the axolemma and associated laterally with it through slender strands. Therefore, we were led to conclude that the axolemma of the squid giant axon was specialized into two domains (microtubule- and microfilament-associated domains) by its underlying cytoskeletons.

scholarly journals Fabrication of High-Strength and Porous Hybrid Scaffolds Based on Nano-Hydroxyapatite and Human-Like Collagen for Bone Tissue Regeneration

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 61 ◽  
Author(s):  
Yannan Liu ◽  
Juan Gu ◽  
Daidi Fan
Keyword(s):  
Mechanical Properties ◽  
Enzymatic Hydrolysis ◽  
Bone Tissue ◽  
Tissue Regeneration ◽  
Bone Repair ◽  
Three Dimensional ◽  
High Strength ◽  
Biological Properties ◽  
Bone Tissue Regeneration

A novel, three-dimensional, porous, human-like collagen (HLC)/nano-hydroxyapatite (n-HA) scaffold cross-linked by 1,2,7,8-diepoxyoctane (DEO) was successfully fabricated, which showed excellent mechanical and superior biological properties for bone tissue regeneration in this study. The physicochemical characterizations of different n-HA/HLC/DEO (nHD) scaffolds were investigated by determining the morphology, compression stress, elastic modulus, Young’s modulus and enzymatic hydrolysis behavior in vitro. The results demonstrated that nHD-2 and nHD-3 scaffolds showed superior mechanical properties and resistance to enzymatic hydrolysis compared to nHD-1 scaffolds. The cell viability, live cell staining and cell adhesion analysis results demonstrated that nHD-2 scaffolds exhibited low cytotoxicity and excellent cytocompatibility compared with nHD-1 and nHD-3 scaffolds. Furthermore, subcutaneous injections of nHD-2 scaffolds in rabbits produced superior anti-biodegradation effects and histocompatibility compared with injections of nHD-1 and nHD-3 scaffolds after 1, 2 and 4 weeks. In addition, the repair of bone defects in rabbits demonstrated that nHD-2 scaffolds presented an improved ability for guided bone regeneration and reconstruction compared to commercially available bone scaffold composite hydroxyapatite/collagen (HC). Collectively, the results show that nHD-2 scaffolds show promise for application in bone tissue engineering due to their excellent mechanical properties, anti-biodegradation, anti-biodegradation, biocompatibility and bone repair effects.

scholarly journals Development and AFM study of porous scaffolds for wound healing applications

2004 ◽  
Vol 18 (4) ◽  
pp. 587-596 ◽  
Author(s):  
T. A. Doneva ◽  
H. B. Yin ◽  
P. Stephens ◽  
W. R. Bowen ◽  
D. W. Thomas
Keyword(s):  
Atomic Force Microscopy ◽  
Wound Healing ◽  
Human Fibroblasts ◽  
Three Dimensional ◽  
Positive Influence ◽  
Porous Scaffolds ◽  
Force Microscopy ◽  
Cellular Assays ◽  
Atomic Force

An engineering approach to the development of biomaterials for promotion of wound healing emphasises the importance of a well‒controlled architecture and concentrates on optimisation of morphology and surface chemistry to stimulate guidance of the cells within the wound environment. A series of three‒dimensional porous scaffolds with 80–90% bulk porosity and fully interconnected macropores were prepared from two biodegradable materials – cellulose acetate (CA) and poly (lactic‒co‒glycolic acid) (PLGA) through the phase inversion mechanism of formation. Surface morphology of obtained scaffolds was determined using atomic force microscopy (AFM) in conjunction with optical microscopy. Scanning Electron Microscopy (SEM) was applied to characterise scaffolds bulk morphology. Biocompatibility and biofunctionality of the prepared materials were assessed through a systematic study of cell/material interactions using atomic force microscopy (AFM) methodologies together within vitrocellular assays. Preliminary data with human fibroblasts demonstrated a positive influence of both scaffolds on cellular attachment and growth. The adhesion of cells on both biomaterials were quantified by AFM force measurements in conjunction with a cell probe technique since, for the first time, a fibroblast probe has been successfully developed and optimal conditions of immobilisation of the cells on the AFM cantilever have been experimentally determined.

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