Evaluation and Biocompatibility of a New Type of Scaffold for Tissue Growth Based on Calcium Phosphate Cement

2008 ◽  
Vol 396-398 ◽  
pp. 667-670 ◽  
Author(s):  
Jéferson Luis de Moraes Machado ◽  
Luis Alberto Santos
Keyword(s):  
Body Fluid ◽  
Three Dimensional ◽  
Sodium Sulphate ◽  
Tissue Growth ◽  
Cellular Growth ◽  
Biological Molecules ◽  
In Vitro Tests ◽  
Porous Scaffolds ◽  
New Type

Growth of cells in three-dimensional porous scaffolds has gaining importance in the field of tissue engineering. The scaffolds guide cellular growth, synthesize extra-cellular matrix and other biological molecules, and make the formation of tissues and functional organs easier. The aim of this work was to use α-TCP (α-tricalcium phosphate) cement in order to obtain such scaffolds, with the aid of paraffin spheres as pores generators. These spheres were produced by suspension in an aqueous solution of polyvinylalcohol (PVA) and sodium sulphate (Na2SO4). The porosity of the scaffolds produced with paraffin spheres was analyzed and compared to the literature, and the study of scaffolds permeability using Forchenheimer equation allowed the analysis of pores interconnectivity. In vitro tests showed the behavior of scaffolds in solutions of SBF (Simulated Body Fluid), and viability and cell proliferation were also evaluated. Use of paraffin spheres showed to be appropriate to the formation of pores suitable size to allow cellular growth.

scholarly journals Robocasting of Bioactive SiO2-P2O5-CaO-MgO-Na2O-K2O Glass Scaffolds

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Francesco Baino ◽  
Jacopo Barberi ◽  
Elisa Fiume ◽  
Gissur Orlygsson ◽  
Jonathan Massera ◽  
...  
Keyword(s):  
Body Fluid ◽  
Bone Repair ◽  
Glass Powder ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
In Vitro Tests ◽  
Text File ◽  
Microstructural Parameters ◽  
Scaffold Architecture

Bioactive silicate glass scaffolds were fabricated by a robocasting process in which all the movements of the printing head were programmed by compiling a script (text file). A printable ink made of glass powder and Pluronic F-127, acting as a binder, was extruded to obtain macroporous scaffolds with a grid-like three-dimensional structure. The scaffold architecture was investigated by scanning electron microscopy and microtomographic analysis, which allowed quantifying the microstructural parameters (pore size 150–180 μm and strut diameter 300 μm). In vitro tests in simulated body fluid (SBF) confirmed the apatite-forming ability (i.e., bioactivity) of the scaffolds. The compressive strength (around 10 MPa for as-produced scaffolds) progressively decreased during immersion in SBF (3.3 MPa after 4 weeks) but remains acceptable for bone repair applications. Taken together, these results (adequate porosity and mechanical strength as well as bioactivity) support the potential suitability of the prepared scaffolds for bone substitution.

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.

Producing Neurospheroids and Hydrogels to Create a Three-dimensional in Vitro Model for the Use of Conduits in Peripheral Nerve Regeneration

Neurosurgery ◽  
2019 ◽  
Vol 84 (5) ◽  
pp. E272-E272
Author(s):  
Devyani Shete ◽  
Aran Batth ◽  
Aditi Nijhawan ◽  
Jaffer Choudhary ◽  
Ian Thompson
Keyword(s):  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Schwann Cells ◽  
Peripheral Nerve Regeneration ◽  
3D Structure ◽  
Three Dimensional ◽  
Negative Control ◽  
Cellular Growth ◽  
Live Cells

Abstract INTRODUCTION Peripheral nerve regeneration is a complex challenge that requires suitable nerve guidance systems to bridge the severed ends of 2 nerves back together. Current polymeric conduits on the market provide good cellular growth but are limited by the length of gap defect they can repair, and complete functional recovery is rare. This project focused on creating a three-dimensional (3D) in Vitro spheroidal sprouting assay for peripheral nerve regeneration, as well as producing and testing different polymeric hydrogels as potential scaffold materials for the conduit. METHODS Different concentrations of chitosan, methylcellulose (MC) and sodium alginate were produced, as well as blends of these materials. These hydrogels were seeded with 3D neurospheroids, along with NG108-15 (neuronal) cells and Schwann cells to test their biocompatibility. RESULTS MTT assays showed the mean absorbance of chitosan gels with NG108-15 cells at 24 hr (P < .001) and 72 hr (P > .05) was similar/slightly higher than the negative control. Live-Dead data showed 93.4% of live cells at DIV7 on MC: Ch blends, compared to 72% with chitosan alone. CONCLUSION Overall, both chitosan and MC were nontoxic and biocompatible with NG108-15 and Schwann cells. Blending chitosan with MC improved its chemical and physical properties. The cells formed spheroids that well on a gel; this pseudo-3D structure is excellent for research purposes compared to 2D as it mimics the body's internal environment.

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.

Vascularized Cardiac Spheroids as Novel 3D in vitro Models to Study Cardiac Fibrosis

2017 ◽  
Vol 204 (3-4) ◽  
pp. 191-198 ◽  
Author(s):  
Gemma A. Figtree ◽  
Kristen J. Bubb ◽  
Owen Tang ◽  
Eddy Kizana ◽  
Carmine Gentile
Keyword(s):  
Growth Factor ◽  
Transforming Growth Factor Beta ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Three Dimensional ◽  
In Vitro Models ◽  
Tissue Growth ◽  
Cardiovascular Research

Spheroid cultures are among the most explored cellular biomaterials used in cardiovascular research, due to their improved integration of biochemical and physiological features of the heart in a defined architectural three-dimensional microenvironment when compared to monolayer cultures. To further explore the potential use of spheroid cultures for research, we engineered a novel in vitro model of the heart with vascularized cardiac spheroids (VCSs), by coculturing cardiac myocytes, endothelial cells, and fibroblasts isolated from dissociated rat neonatal hearts (aged 1-3 days) in hanging drop cultures. To evaluate the validity of VCSs in recapitulating pathophysiological processes typical of the in vivo heart, such as cardiac fibrosis, we then treated VCSs with transforming growth factor beta 1 (TGFβ1), a known profibrotic agent. Our mRNA analysis demonstrated that TGFβ1-treated VCSs present elevated levels of expression of connective tissue growth factor, fibronectin, and TGFβ1 when compared to control cultures. We demonstrated a dramatic increase in collagen deposition following TGFβ1 treatment in VCSs in the PicroSirius Red-stained sections. Doxorubicin, a renowned cardiotoxic and profibrotic agent, triggered apoptosis and disrupted vascular networks in VCSs. Taken together, our findings demonstrate that VCSs are a valid model for the study of the mechanisms involved in cardiac fibrosis, with the potential to be used to investigate novel mechanisms and therapeutics for treating and preventing cardiac fibrosis in vitro.

DEGRADATION BEHAVIOR OF A BIODEGRADABLE Fe-Mn ALLOY PRODUCED BY POWDER SINTERING

2012 ◽  
Vol 06 ◽  
pp. 774-779
Author(s):  
QIAN ZHANG ◽  
X. G. Wang ◽  
PENG CAO ◽  
WEI GAO
Keyword(s):  
Simulated Body Fluid ◽  
Body Fluid ◽  
Degradation Rate ◽  
Hardness Measurement ◽  
Degradation Behavior ◽  
Biodegradable Metal ◽  
Powder Sintering ◽  
New Type ◽  
Powder Compacts

Biodegradable stenting and implantation materials have received considerable attention in biomaterials community, with magnesium having been received most wide attention. However, magnesium corrodes too fast by nature, in human body environment. A new type of biodegradable metal – Fe and its alloys – has been introduced in recent years. In this study, a Fe 35 wt % Mn alloy was produced using powder sintering. Powder mixture was mechanically milled, pressed and then sintered to consolidate powder compacts. Microstructure characterization and hardness measurement were carried out on the as-sintered samples. In vitro degradability evaluation of the samples was performed in 5% NaCl and Simulated Body Fluid (SBF) media. The experimental results show that a higher porosity results in a higher degradation rate. All samples, with porosity being from 6.5% to 12.2 %, revealed a degradation rate from 0.6 to 1.4 mm/year.

Effects of Mechanical Stress on the In Vitro Degradation of Porous Composite Scaffold for Bone Tissue Engineering

2007 ◽  
Vol 342-343 ◽  
pp. 273-276 ◽  
Author(s):  
Yun Qing Kang ◽  
Guang Fu Yin ◽  
Lin Luo ◽  
Ke Feng Wang ◽  
Yu Zhang
Keyword(s):  
Tissue Engineering ◽  
Simulated Body Fluid ◽  
Bone Tissue Engineering ◽  
Mechanical Stress ◽  
Mechanical Loading ◽  
Body Fluid ◽  
Compressive Loading ◽  
Porous Scaffolds ◽  
In Vitro Degradation

In bone tissue engineering, porous scaffolds served as the temporary matrix are often subjected to mechanical stress when implanted in the body. Based on this fact, the goal of this study was to examine the effects of mechanical loading on the in vitro degradation characteristics and kinetics of porous scaffolds in a custom-designed loading system. Porous Poly(L-lactic acid)/β-Tricalcium Phosphate (PLLA/β-TCP) composite scaffolds fabricated by using solution casting/compression molding/particulate leaching technique (SCP) were subjected to degradation in simulated body fluid (SBF) at 37°C for up to 6 weeks under the conditions: with and without static compressive loading, respectively. The results indicated that the increase of the porosity and decrease of the compressive strength under static compressive loading were slower than that of non-loading case, and so did the mass loss rate. It might be due to that the loading retarded the penetration, absorption and transfer of simulated body fluid. These data provide an important step towards understanding mechanical loading factors contributing to degradation.

scholarly journals An Unbiased Functional Genetics Screen Identifies Rare Activating ERBB4 Mutations

2022 ◽  
Vol 2 (1) ◽  
pp. 10-27
Author(s):  
Deepankar Chakroborty ◽  
Veera K. Ojala ◽  
Anna M. Knittle ◽  
Jasmin Drexler ◽  
Mahlet Z. Tamirat ◽  
...  
Keyword(s):  
Kinase Inhibitors ◽  
Three Dimensional ◽  
Culture Conditions ◽  
Cellular Growth ◽  
Expression Library ◽  
Functional Genetics ◽  
Mutational Hotspots ◽  
Cancer Types

Despite the relatively high frequency of somatic ERBB4 mutations in various cancer types, only a few activating ERBB4 mutations have been characterized, primarily due to lack of mutational hotspots in the ERBB4 gene. Here, we utilized our previously published pipeline, an in vitro screen for activating mutations, to perform an unbiased functional screen to identify potential activating ERBB4 mutations from a randomly mutated ERBB4 expression library. Ten potentially activating ERBB4 mutations were identified and subjected to validation by functional and structural analyses. Two of the 10 ERBB4 mutants, E715K and R687K, demonstrated hyperactivity in all tested cell models and promoted cellular growth under two-dimensional and three-dimensional culture conditions. ERBB4 E715K also promoted tumor growth in in vivo Ba/F3 cell mouse allografts. Importantly, all tested ERBB4 mutants were sensitive to the pan-ERBB tyrosine kinase inhibitors afatinib, neratinib, and dacomitinib. Our data indicate that rare ERBB4 mutations are potential candidates for ERBB4-targeted therapy with pan-ERBB inhibitors. Statement of Significance: ERBB4 is a member of the ERBB family of oncogenes that is frequently mutated in different cancer types but the functional impact of its somatic mutations remains unknown. Here, we have analyzed the function of over 8,000 randomly mutated ERBB4 variants in an unbiased functional genetics screen. The data indicate the presence of rare activating ERBB4 mutations in cancer, with potential to be targeted with clinically approved pan-ERBB inhibitors.

Development of HA-PLGA Scaffold Encapsulating Intact BMP-2 Using Solid Freeform Fabrication Technology

2011 ◽  
Author(s):  
Jin-Hyung Shim ◽  
Jong Young Kim ◽  
Kyung Shin Kang ◽  
Jung Kyu Park ◽  
Sei Kwang Hahn ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Bone Regeneration ◽  
Porous Scaffold ◽  
Solid Freeform Fabrication ◽  
Three Dimensional ◽  
Porous Scaffolds ◽  
Prolonged Release ◽  
Cellular Activity ◽  
Freeform Fabrication

Tissue engineering is an interdisciplinary field that focuses on restoring and repairing tissues or organs. Cells, scaffolds, and biomolecules are recognized as three main components of tissue engineering. Solid freeform fabrication (SFF) technology is required to fabricate three-dimensional (3D) porous scaffolds to provide a 3D environment for cellular activity. SFF technology is especially advantageous for achieving a fully interconnected, porous scaffold. Bone morphogenic protein-2 (BMP-2), an important biomolecule, is widely used in bone tissue engineering to enhance bone regeneration activity. However, methods for the direct incorporation of intact BMP-2 within 3D scaffolds are rare. In this work, 3D porous scaffolds with poly(lactic-co-glycolic acid) chemically grafted hyaluronic acid (HA-PLGA), in which intact BMP-2 was directly encapsulated, were successfully fabricated using SFF technology. BMP-2 was previously protected by poly(ethylene glycol) (PEG), and the BMP-2/PEG complex was incorporated in HA-PLGA using an organic solvent. The HAPLGA/PEG/BMP-2 mixture was dissolved in chloroform and deposited via a multi-head deposition system (MHDS), one type of SFF technology, to fabricate a scaffold for tissue engineering. An additional air blower system and suction were installed in the MHDS for the solvent-based fabrication method. An in vitro evaluation of BMP-2 release was conducted, and prolonged release of intact BMP-2, for up to 28 days, was confirmed. After confirmation of advanced proliferation of pre osteoblasts, a superior differentiation effect of the HA-PLGA/PEG/BMP-2 scaffold was validated by measuring high expression levels of bone-specific markers, such as alkaline phosphatase (ALP) and osteocalcin (OC). We show that our solvent-based fabrication is a non-toxic method for restoring cellular activity. Moreover, the HAPLGA/PEG/BMP-2 scaffold was effective for bone regeneration.

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