scholarly journals Biofabrication of Electrospun Scaffolds for the Regeneration of Tendons and Ligaments

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1963 ◽  
Author(s):  
Alberto Sensini ◽  
Luca Cristofolini
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Tissue Regeneration ◽  
Electrospun Scaffolds ◽  
General Overview ◽  
Different Types ◽  
Non Linear ◽  
Nanometric Size ◽  
Ligament Tissue Engineering

Tendon and ligament tissue regeneration and replacement are complex since scaffolds need to guarantee an adequate hierarchical structured morphology, and non-linear mechanical properties. Moreover, to guide the cells’ proliferation and tissue re-growth, scaffolds must provide a fibrous texture mimicking the typical of the arrangement of the collagen in the extracellular matrix of these tissues. Among the different techniques to produce scaffolds, electrospinning is one of the most promising, thanks to its ability to produce fibers of nanometric size. This manuscript aims to provide an overview to researchers approaching the field of repair and regeneration of tendons and ligaments. To clarify the general requirements of electrospun scaffolds, the first part of this manuscript presents a general overview concerning tendons’ and ligaments’ structure and mechanical properties. The different types of polymers, blends and particles most frequently used for tendon and ligament tissue engineering are summarized. Furthermore, the focus of the review is on describing the different possible electrospinning setups and processes to obtain different nanofibrous structures, such as mats, bundles, yarns and more complex hierarchical assemblies. Finally, an overview concerning how these technologies are exploited to produce electrospun scaffolds for tendon and ligament tissue applications is reported together with the main findings and outcomes.

scholarly journals 3D Printing for Soft Tissue Regeneration and Applications in Medicine

Biomedicines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 336
Author(s):  
Sven Pantermehl ◽  
Steffen Emmert ◽  
Aenne Foth ◽  
Niels Grabow ◽  
Said Alkildani ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Additive Manufacturing ◽  
Soft Tissue ◽  
3D Printing ◽  
Tissue Regeneration ◽  
Research Area ◽  
Modern Medicine ◽  
Soft Tissue Regeneration ◽  
General Overview

The use of additive manufacturing (AM) technologies is a relatively young research area in modern medicine. This technology offers a fast and effective way of producing implants, tissues, or entire organs individually adapted to the needs of a patient. Today, a large number of different 3D printing technologies with individual application areas are available. This review is intended to provide a general overview of these various printing technologies and their function for medical use. For this purpose, the design and functionality of the different applications are presented and their individual strengths and weaknesses are explained. Where possible, previous studies using the respective technologies in the field of tissue engineering are briefly summarized.

scholarly journals Harnessing the Topography of 3D Spongy-Like Electrospun Bundled Fibrous Scaffold via a Sharply Inclined Array Collector

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1444 ◽  
Author(s):  
Sun Hee Cho ◽  
Jeong In Kim ◽  
Cheol Sang Kim ◽  
Chan Hee Park ◽  
In Gi Kim
Keyword(s):  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Three Dimensional ◽  
Living System ◽  
Pivotal Role ◽  
Skin Tissue ◽  
Target Tissue ◽  
Fibrous Scaffold ◽  
Electrospun Scaffolds ◽  
Directional Change

To date, many researchers have studied a considerable number of three-dimensional (3D) cotton-like electrospun scaffolds for tissue engineering, including the generation of bone, cartilage, and skin tissue. Although numerous 3D electrospun fibrous matrixes have been successfully developed, additional research is needed to produce 3D patterned and sophisticated structures. The development of 3D fibrous matrixes with patterned and sophisticated structures (FM-PSS) capable of mimicking the extracellular matrix (ECM) is important for advancing tissue engineering. Because modulating nano to microscale features of the 3D fibrous scaffold to control the ambient microenvironment of target tissue cells can play a pivotal role in inducing tissue morphogenesis after transplantation in a living system. To achieve this objective, the 3D FM-PSSs were successfully generated by the electrospinning using a directional change of the sharply inclined array collector. The 3D FM-PSSs overcome the current limitations of conventional electrospun cotton-type 3D matrixes of random fibers.

scholarly journals Alginate/Gelatin Hydrogels Reinforced with TiO2 and β-TCP Fabricated by Microextrusion-based Printing for Tissue Regeneration

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 457 ◽  
Author(s):  
Rodrigo Urruela-Barrios ◽  
Erick Ramírez-Cedillo ◽  
A. Díaz de León ◽  
Alejandro Alvarez ◽  
Wendy Ortega-Lara
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Tissue Regeneration ◽  
Average Pore Size ◽  
Three Dimensional ◽  
Engineering Applications ◽  
Average Pore ◽  
Viscous Deformation ◽  
Freeze Dried ◽  
3D Printed

Three-dimensional (3D) printing technologies have become an attractive manufacturing process to fabricate scaffolds in tissue engineering. Recent research has focused on the fabrication of alginate complex shaped structures that closely mimic biological organs or tissues. Alginates can be effectively manufactured into porous three-dimensional networks for tissue engineering applications. However, the structure, mechanical properties, and shape fidelity of 3D-printed alginate hydrogels used for preparing tissue-engineered scaffolds is difficult to control. In this work, the use of alginate/gelatin hydrogels reinforced with TiO2 and β-tricalcium phosphate was studied to tailor the mechanical properties of 3D-printed hydrogels. The hydrogels reinforced with TiO2 and β-TCP showed enhanced mechanical properties up to 20 MPa of elastic modulus. Furthermore, the pores of the crosslinked printed structures were measured with an average pore size of 200 μm. Additionally, it was found that as more layers of the design were printed, there was an increase of the line width of the bottom layers due to its viscous deformation. Shrinkage of the design when the hydrogel is crosslinked and freeze dried was also measured and found to be up to 27% from the printed design. Overall, the proposed approach enabled fabrication of 3D-printed alginate scaffolds with adequate physical properties for tissue engineering applications.

scholarly journals Glycosaminoglycans: From Vascular Physiology to Tissue Engineering Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Antonio Junior Lepedda ◽  
Gabriele Nieddu ◽  
Marilena Formato ◽  
Matthew Brandon Baker ◽  
Julia Fernández-Pérez ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Growth Factors ◽  
Tissue Regeneration ◽  
Vascular Tissue ◽  
Small Diameter ◽  
Relative Molecular Mass ◽  
Vascular Cells ◽  
Vascular Events ◽  
Vascular Regeneration

Cardiovascular diseases represent the number one cause of death globally, with atherosclerosis a major contributor. Despite the clinical need for functional arterial substitutes, success has been limited to arterial replacements of large-caliber vessels (diameter > 6 mm), leaving the bulk of demand unmet. In this respect, one of the most challenging goals in tissue engineering is to design a “bioactive” resorbable scaffold, analogous to the natural extracellular matrix (ECM), able to guide the process of vascular tissue regeneration. Besides adequate mechanical properties to sustain the hemodynamic flow forces, scaffold’s properties should include biocompatibility, controlled biodegradability with non-toxic products, low inflammatory/thrombotic potential, porosity, and a specific combination of molecular signals allowing vascular cells to attach, proliferate and synthesize their own ECM. Different fabrication methods, such as phase separation, self-assembly and electrospinning are currently used to obtain nanofibrous scaffolds with a well-organized architecture and mechanical properties suitable for vascular tissue regeneration. However, several studies have shown that naked scaffolds, although fabricated with biocompatible polymers, represent a poor substrate to be populated by vascular cells. In this respect, surface functionalization with bioactive natural molecules, such as collagen, elastin, fibrinogen, silk fibroin, alginate, chitosan, dextran, glycosaminoglycans (GAGs), and growth factors has proven to be effective. GAGs are complex anionic unbranched heteropolysaccharides that represent major structural and functional ECM components of connective tissues. GAGs are very heterogeneous in terms of type of repeating disaccharide unit, relative molecular mass, charge density, degree and pattern of sulfation, degree of epimerization and physicochemical properties. These molecules participate in a number of vascular events such as the regulation of vascular permeability, lipid metabolism, hemostasis, and thrombosis, but also interact with vascular cells, growth factors, and cytokines to modulate cell adhesion, migration, and proliferation. The primary goal of this review is to perform a critical analysis of the last twenty-years of literature in which GAGs have been used as molecular cues, able to guide the processes leading to correct endothelialization and neo-artery formation, as well as to provide readers with an overall picture of their potential as functional molecules for small-diameter vascular regeneration.

Scaffolds and Tissue Engineering Applications by 3D Bio-Printing Process

2021 ◽  
pp. 718-733
Author(s):  
Ranjit Barua ◽  
Sudipto Datta ◽  
Pallab Datta ◽  
Amit Roy Chowdhury
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Manufacturing Process ◽  
Cross Linking ◽  
Engineering Applications ◽  
Printing Process ◽  
Important Thing ◽  
Bone Scaffolds ◽  
Complex Design ◽  
Different Types

3D bio-printing is a revolutionary manufacturing process that is widely used in medical fields especially in preparing bone scaffolds and tissue engineering. With the help of new biocompatible material like polymers, bio-gels, ceramics, this technology has created a new site in advanced tissue engineering and scaffolds manufacturing area. Another important thing is that, with the use of CAD file software, any complex design can be prepared (i.e., this technology does not have any limited sites). But here it is very much essential to study and analyze machine printability characteristics, cross-linking time and biocompatibility of printing objects as well as bio-ink. However, mechanical properties like shear thinning, mechanical elasticity are also required. In this chapter, different types of scaffold-preparing methods and the bio-printing process are discussed, which are used in scaffold and tissue engineering.

Natural Scaffold, from Bovine Bone Marrow, Reproduces Native Microenvironment and Supports CD34+ and Stromal Cells

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 2400-2400
Author(s):  
Renata Giardini Rosa ◽  
Juares E. Romero Bianco ◽  
Gabriela Pereira dos Santos ◽  
Stephen D. Waldman ◽  
Joanna Weber ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Marrow ◽  
Extracellular Matrix ◽  
Tissue Regeneration ◽  
Stromal Cells ◽  
Bovine Bone ◽  
Ecm Proteins ◽  
Histological Staining

Abstract Background: The idea of studying bone marrow outside its native environment is attractive and ideal. Due to the many functions of extracellular matrix (ECM), currently there is an interest in creating an environment that mimics the ECM present in the tissue, similar to the microenvironment in vivo. Molds replacing the ECM (scaffolds) have a porous structure and may assist the tissue regeneration by forming a suitable environment for adhesion, migration, proliferation and cellular differentiation. The appropriate ECM is a key factor as ECM proteins are site-specific and provide protein 'footprints' of previous resident cells. Because ECM proteins are among the most conserved proteins, the removal of xenogenic/allogenic cellular contents via decellularization could theoretically produce an essentially minimally immunogenic scaffold with a native intact structure for new tissue regeneration. Thus, the search for a scaffold that could be used to assess the behavior of cells and their interactions with the ECM in vitro/in vivo, and has different niches in its composition is highly desirable. Aims: In recent years, a large number of molecular and cytogenetic abnormalities have been identified in AML, MDS and multiple myeloma, many of these defects can serve as markers for diagnosis/prognosis or as therapeutic targets. However, there are still many unknown molecular factors involved in genetic abnormalities or signaling pathways that contribute to the pathogenesis of the disease. Another very important aspect of these diseases is that they all are related to the mutual interaction of neoplastic cells and the microenvironment of bone marrow. In the absence of an ideal model or even the difficulty in reproduce a native environment, we proposed the characterization of a natural scaffold, from bovine bone marrow, which can be used as a study model, previously patented by our laboratory. Materials and Methods: Bone marrow was decellularized by one or more incubations in an enzymatic digestion solution and polar solvent extractions, comprising an extracellular matrix with well-preserved 3D structure. Scaffolds were analyzed after the decelularization process for potential changes in structure (TEM, SEM, Histological staining, and immunohistochemistry for collagen III, IV, fibronectin) and mechanical properties. To verify if the scaffold would hold and support cell survival and extracellular matrix production, an in vitro study was performed using CD34+ (non-stromal) and HS-5 (stromal) cells. Cell-seeded decellularized scaffolds were cultured for 7-14 days and analyzed for Histological staining. Results: Histology sections (H&E staining), TEM and SEM demonstrated the structure and ultrastructure of the processed matrix and confirmed both cellular extraction and preservation of the macroscopic 3-D architecture of the collagen fibers, blood vessels, and preservation of an organized matrix. Also, the decellularized scaffold was quite comparable to the native tissue in terms of its mechanical properties. Immunohistochemistry of the scaffold showed that the main components of the ECM were preserved. The in vitro experiments of both stromal cells (HS-5) and non-stromal cells (CD34+) demonstrated that they were able to adhere and in the HS-5 case also produce ECM during 7-14 days of culture. In both cases, an increase in cell number was observed and CD34+ overtime formed cluster and with 14 days of culture the cluster formation increased in size. Conclusions: The results demonstrated that the decellularization process was efficient in keeping a 3-D structure and mechanical properties with a well-organized-preserved ECM. In vitro experiments showed that both CD34+ and HS-5 were able to proliferate and adhere in specific sites of the scaffold, suggesting that they were able to recognize their native environment. HS-5 produced ECM indicating that the scaffold worked as an optimal microenvironment. In conclusion, the scaffold could be used as a model, which has the potential to mimic the native microenvironment to enable research/studies of factors that are involved in self-renewal and maintenance of neoplastic cells in bone marrow. Also, this model could be very useful for pharmacological testing of bone marrow in vitro. Disclosures No relevant conflicts of interest to declare.

scholarly journals The development of a decellularized extracellular matrix–based biomaterial scaffold derived from human foreskin for the purpose of foreskin reconstruction in circumcised males

2018 ◽  
Vol 9 ◽  
pp. 204173141881261 ◽  
Author(s):  
Valeria Purpura ◽  
Elena Bondioli ◽  
Eric J Cunningham ◽  
Giovanni De Luca ◽  
Daniela Capirossi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Growth Factor ◽  
Tensile Stress ◽  
Fibroblast Growth Factor ◽  
Fibroblast Growth ◽  
Stress Tests ◽  
Viable Cells ◽  
Dermal Matrices

The circumcision of males is emphatically linked to numerous sexual dysfunctions. Many of the purported benefits do not hold up to the scrutiny of extensive literature surveys. Involuntary circumcision, particularly when not medically warranted, is also associated with many psychological and emotional traumas. Current methods to reconstruct the ablated tissue have significant drawbacks and produce a simple substitute that merely imitates the natural foreskin. Extracellular matrix–based scaffolds have been shown to be highly effective in the repair and regeneration of soft tissues; however, due to the unique nature of the foreskin tissue, commercially available biomaterial scaffolds would yield poor results. Therefore, this study discusses the development and evaluation of a tissue engineering scaffold derived from decellularized human foreskin extracellular matrix for foreskin reconstruction. A chemicophysical decellularization method was applied to human foreskin samples, sourced from consenting adult donors. The resulting foreskin dermal matrices were analyzed for their suitability for tissue engineering purposes, by biological, histological, and mechanical assessment; fresh frozen foreskin was used as a negative control. Sterility of samples at all stages was ensured by microbiological analysis. MTT assay was used to evaluate the absence of viable cells, and histological analysis was used to confirm the maintenance of the extracellular matrix structure and presence/integrity of collagen fibers. Bioactivity was determined by submitting tissue extracts to enzyme-linked immunosorbent assay and quantifying basic fibroblast growth factor content. Mechanical properties of the samples were determined using tensile stress tests. Results found foreskin dermal matrices were devoid of viable cells ( p < 0.0001) and the matrix of foreskin dermal matrices was maintained. Basic fibroblast growth factor content doubled within after decellularization ( p < 0.0001). Tensile stress tests found no statistically significant differences in the mechanical properties ( p < 0.05). These results indicate that the derived foreskin dermal matrix may be suitable in a regenerative approach in the reconstruction of the human foreskin.

scholarly journals Detergent-Enzymatic Decellularization of Swine Blood Vessels: Insight on Mechanical Properties for Vascular Tissue Engineering

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Alessandro F. Pellegata ◽  
M. Adelaide Asnaghi ◽  
Ilaria Stefani ◽  
Anna Maestroni ◽  
Silvia Maestroni ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tissue Engineering ◽  
Extracellular Matrix ◽  
Vascular Tissue ◽  
Complete Removal ◽  
Vascular Tissue Engineering ◽  
Promising Tool ◽  
Complete Cell ◽  
Synthetic Grafts

Small caliber vessels substitutes still remain an unmet clinical need; few autologous substitutes are available, while synthetic grafts show insufficient patency in the long term. Decellularization is the complete removal of all cellular and nuclear matters from a tissue while leaving a preserved extracellular matrix representing a promising tool for the generation of acellular scaffolds for tissue engineering, already used for various tissues with positive outcomes. The aim of this work is to investigate the effect of a detergent-enzymatic decellularization protocol on swine arteries in terms of cell removal, extracellular matrix preservation, and mechanical properties. Furthermore, the effect of storage at −80°C on the mechanical properties of the tissue is evaluated. Swine arteries were harvested, frozen, and decellularized; histological analysis revealed complete cell removal and preserved extracellular matrix. Furthermore, the residual DNA content in decellularized tissues was far low compared to native one. Mechanical testings were performed on native, defrozen, and decellularized tissues; no statistically significant differences were reported for Young’s modulus, ultimate stress, compliance, burst pressure, and suture retention strength, while ultimate strain and stress relaxation of decellularized vessels were significantly different from the native ones. Considering the overall results, the process was confirmed to be suitable for the generation of acellular scaffolds for vascular tissue engineering.

Sign in / Sign up

Export Citation Format

Share Document