Nanofibrous Scaffolds For Tissue Engineering Research Articles

Fabrication of glycidyl methacrylate-modified silk fibroin/poly(L-lactic acid-co-ε-caprolactone)–polyethylene glycol diacrylate hybrid 3D nanofibrous scaffolds for tissue engineering

Fabrication of glycidyl methacrylate-modified silk fibroin/poly(L-lactic acid-co-ε-caprolactone)–polyethylene glycol diacrylate hybrid 3D nanofibrous scaffolds for tissue engineering

Polycaprolactone-MXene Nanofibrous Scaffolds for Tissue Engineering.

New conductive materials for tissue engineering are needed for the development of regenerative strategies for nervous, muscular, and heart tissues. Polycaprolactone (PCL) is used to obtain biocompatible and biodegradable nanofiber scaffolds by electrospinning. MXenes, a large class of biocompatible 2D nanomaterials, can make polymer scaffolds conductive and hydrophilic. However, an understanding of how their physical properties affect potential biomedical applications is still lacking. We immobilized Ti3C2Tx MXene in several layers on the electrospun PCL membranes and used positron annihilation analysis combined with other techniques to elucidate the defect structure and porosity of nanofiber scaffolds. The polymer base was characterized by the presence of nanopores. The MXene surface layers had abundant vacancies at temperatures of 305-355 K, and a voltage resonance at 8 × 104 Hz with the relaxation time of 6.5 × 106 s was found in the 20-355 K temperature interval. The appearance of a long-lived component of the positron lifetime was observed, which was dependent on the annealing temperature. The study of conductivity of the composite scaffolds in a wide temperature range, including its inductive and capacity components, showed the possibility of the use of MXene-coated PCL membranes as conductive biomaterials. The electronic structure of MXene and the defects formed in its layers were correlated with the biological properties of the scaffolds in vitro and in bacterial adhesion tests. Double and triple MXene coatings formed an appropriate environment for cell attachment and proliferation with mild antibacterial effects. A combination of structural, chemical, electrical, and biological properties of the PCL-MXene composite demonstrated its advantage over the existing conductive scaffolds for tissue engineering.

Synthesis and Characterization of Graphene-doped Nanofibrous Scaffolds for Tissue Engineering

Synthesis and Characterization of Graphene-doped Nanofibrous Scaffolds for Tissue Engineering

Polycaprolactone/Gelatin Nanofibrous Scaffolds for Tissue Engineering

The combined use of polycaprolactone and gelatin has obviated many drawbacks associated with applying them alone. Polycaprolactone provides mechanical strength and buys sufficient time for tissue regeneration without degradation. Simultaneously, gelatin regulates the surface wettability of the composite scaffold. It makes the structure more cytocompatible by its cell recognition sites. Furthermore, these low polymers' cost, biocompatibility, and tuning of degradation time have added to their therapeutic appeal. In the current study, we have reviewed the application of polycaprolactone/gelatin scaffolds in tissue engineering and drug delivery fields, hoping to translate these scaffolds into medicine.

Hydrophilic Surface Functionalization of Electrospun Nanofibrous Scaffolds in Tissue Engineering.

Electrospun polymer nanofibers have received much attention in tissue engineering due to their valuable properties such as biocompatibility, biodegradation ability, appropriate mechanical properties, and, most importantly, fibrous structure, which resembles the morphology of extracellular matrix (ECM) proteins. However, they are usually hydrophobic and suffer from a lack of bioactive molecules, which provide good cell adhesion to the scaffold surface. Post-electrospinning surface functionalization allows overcoming these limitations through polar groups covalent incorporation to the fibers surface, with subsequent functionalization with biologically active molecules or direct deposition of the biomolecule solution. Hydrophilic surface functionalization methods are classified into chemical approaches, including wet chemical functionalization and covalent grafting, a physiochemical approach with the use of a plasma treatment, and a physical approach that might be divided into physical adsorption and layer-by-layer assembly. This review discusses the state-of-the-art of hydrophilic surface functionalization strategies of electrospun nanofibers for tissue engineering applications. We highlighted the major advantages and drawbacks of each method, at the same time, pointing out future perspectives and solutions in the hydrophilic functionalization strategies.

Evaluation of the potential of chimeric spidroins/poly(L-lactic-co-ε-caprolactone) (PLCL) nanofibrous scaffolds for tissue engineering.

In this study, a novel type of chimeric spider silk proteins (spidroins) NTW1-4CT was blended with poly(L-lactic-co-ε-caprolactone) (PLCL) to obtain nanofibrous scaffolds via electrospinning. Spidroins are composed of a N-terminal module (NT) from major ampullate spidroins, a C-terminal module (CT) from minor ampullate spidroins and 1-4 repeat modules (W) from aciniform spidroins. Physical characteristics and structures of NTW1-4CT/PLCL (25/75, w/w) blend scaffolds were carried out by scanning electron microscope (SEM), water contact angles measurements, Fourier transform infrared (FTIR) spectroscopy and tensile mechanical tests. Results showed that blending with spidroins decreased diameters of nanofibers and increased porosity and wettability of scaffolds. Additionally, chimeric spidroins undergone a similar structural transition in electrospinning process as with the formation process of native and artificial spider silks from other spidroins. With amounts of W modules increasing, the tensile strength and elongation of blend scaffolds were also increased. Particularly, NTW4CT/PLCL (25/75) scaffolds revealed much higher breaking stress than pure PLCL scaffolds. In vitro experiments, human umbilical vein endothelial cells (HUVEC) cultured on NTW4CT/PLCL (25/75) scaffolds displayed significantly higher activity of proliferation and adhesion than on pure PLCL scaffolds. All results suggested that chimeric spidroins/PLCL, especially NTW4CT/PLCL (25/75) blend nanofibrous scaffolds had promising potential for vascular tissue engineering.

Fabrication of Poly(ε-Caprolactone), Hydrophilic and β-Tricalcium Phosphate Layer- by -Layer Nanofibrous Scaffolds for Tissue Engineering

Fabrication of Poly(ε-Caprolactone), Hydrophilic and β-Tricalcium Phosphate Layer- by -Layer Nanofibrous Scaffolds for Tissue Engineering

Fabrication of Three-Dimensional Fluffy Nanofibrous Scaffolds for Tissue Engineering via Electrospinning and CO2 Escaping Foaming

Electrospinning is a widely used technique to fabricate a nanofibrous scaffold to resemble the extracellular matrix (ECM) in tissue engineering. However, the intrinsic property (dense structure and...

A review: Nanofibrous scaffold in possible prevention and treatment of coronary artery disease.

Nanofibrous scaffolds have potential to improve coronary stent applications by promoting endothelial recovery on the stent surface and aids regeneration of cardiac tissues. Presently, scaffolds fabricated via electro-spinning are been widely used because of their ability to bio-mimic the precise anatomical structure of the protein fibers. Properties like convenience to spin on several components and functionalization with several bioactive molecules have signify the use of nanofibrous scaffolds for tissue engineering. This review highlights some recent applications of electrospun nanofibrous scaffolds in the treatment and management of cardiac arterial diseases and engineering new cardiac tissues.

Development of PVA/gelatin nanofibrous scaffolds for Tissue Engineering via electrospinning

The electrospinning process is an emerging and relatively easy technique to prepare three-dimensional matrices with micro- and nanofibers. To achieve it, aqueous polymer solutions from synthetic or natural polymers are used. PVA was selected as polymer and gelatin because of its biocompatibility and biodegradability. A complete characterization of the polymeric solutions (density, surface tension, etc) was previously performed. Subsequently, a standard electrospinning process (15 kV, 0.4 ml h−1 and 10 cm) was carried out to obtain scaffolds. The influence of the polymer concentration and the protein addition was observed by performing FTIR analyses and studied by analyzing the water contact angle and SEM images.

Development and characterization of heparin-immobilized polycaprolactone nanofibrous scaffolds for tissue engineering using gamma-irradiation

Polycaprolactone (PCL) has been considered a useful material for orthopedic devices and osseous implants because of its biocompatibility and bone-forming activity.

Investigation of microporous composite scaffolds fabricated by embedding sacrificial polyethylene glycol microspheres in nanofibrous membrane

The application of electrospun nanofibrous scaffolds in tissue engineering is limited due to their small pore size which leads to the failure of cell infiltration into the scaffolds. Microporous silk fibroin (SF)/gelatin composite scaffolds with biological properties could be fabricated to mimic tissue structure for tissue engineering applications. This study aimed to present a simple method to fabricate the composite scaffolds which is based on the simultaneously electrospraying of microspheres and electrospinning of nanofibers. Different contents of polyethylene glycol (PEG) microspheres were embedded into the SF/gelatin nanofibrous membranes by varying the content of PEG microsphere. Furthermore, microspheres can be selectively leached, obtaining the single SF/gelatin nanofibrous scaffolds and retaining the hierarchical organization of the porous nanofibers. In conclusion, the multilevel microporous and nanofibrous composite scaffolds can be obtained by varying pump flow rate of electrospraying.

2D imprinted substrates and 3D electrospun scaffolds revolutionize biomedicine.

Momentous advances in engineering in the 1980s and 1990s reduced significantly the manufacturing cost of equipment that can produce nano to low microscale materials. This was a key milestone in the field of biomedicine, as from the early 2000s, we entered the era of nanobiomedicine. Essentially, with very low capital cost, every laboratory in the world could develop cell culture substrates and/or implantable devices with morphological features down to the nanometer scale. The rationale of using such small dimensional features derives from the fact that the extracellular space is comprised of nanoto microscale supramolecular assemblies. Further, cells employ probing filopodia extensions and contractile intracellular machinery to gather topographical, spatial, mechanical and chemical information from the extracellular environment, which consequently determines cell functionality, lineage commitment and fate. Among the various fabrication technologies, lithography constitutes the most popular 2D top-down method, while electrospinning represents the most widely used 3D bottomup method [1–7]. The produced 2D and 3D constructs have enabled the study of cell and tissue responses at previously economical and technological prohibiting small scales and the rational design thereof for a specific application/clinical indication. Key to the design tenant is that topographical features and morphological structures should promote cellular polarization and organized extracellular matrix assembly, resembling the natural conformation of tissues. Using photolithography back in 1983, microscale V-shape grooves were created to study human gingival and porcine epithelial cell response [8]. By 1997, we were in a position to fabricate substrates with feature (square) accuracy down to 14 nm (depth) to study Xenopus neurites outgrowth using electron-beam lithography [9,10]. To date, we have successfully imprinted various gratings and geometric shapes along different scales onto thermoplastic polymers to create biologically relevant topographical interfaces. Data obtained from these and other studies clearly illustrate that topographical features are powerful modulators of cell morphology and differential function [11–15]. Further, nanoand microscale arrays have been shown to be potent tools in maintaining the phenotype fidelity of permanently differentiated cells and in differentiating stem cells toward specific lineages [16,17]. Multiple topographic arrays have also been used as high-throughput systems to elucidate the cell–surface interactions and enable identification of improved surfaces for optimal/required cell response [18,19]. Specifically, topographical features have been shown to directly modulate cell–material interaction and to affect the composition, orientation and conformation of adsorbed extracellular matrix components [20,21]. Further, nanoimprinted materials have been shown to either 2D imprinted substrates and 3D electrospun scaffolds revolutionize biomedicine

Electrospun Poly(lactide-co-glycolide-co-3(S)-methyl-morpholine-2,5-dione) Nanofibrous Scaffolds for Tissue Engineering.

Biomimetic scaffolds have been investigated in vascular tissue engineering for many years. Excellent biodegradable materials are desired as temporary scaffolds to support cell growth and disappear gradually with the progress of guided tissue regeneration. In the present paper, a series of biodegradable copolymers were synthesized and used to prepared micro/nanofibrous scaffolds for vascular tissue engineering. Poly(lactide-co-glycolide-co-3(S)-methyl-morpholine-2,5-dione) [P(LA-co-GA-co-MMD)] copolymers with different l-lactide (LA), glycolide (GA), and 3(S)-methyl-2,5-morpholinedione (MMD) contents were synthesized using stannous octoate as a catalyst. Moreover, the P(LA-co-GA-co-MMD) nanofibrous scaffolds were prepared by electrospinning technology. The morphology of scaffolds was analyzed by scanning electron microscopy (SEM), and the results showed that the fibers are smooth, regular, and randomly oriented with diameters of 700 ± 100 nm. The weight loss of scaffolds increased significantly with the increasing content of MMD, indicating good biodegradable property of the scaffolds. In addition, the cytocompatibility of electrospun nanofibrous scaffolds was tested by human umbilical vein endothelial cells. It is demonstrated that the cells could attach and proliferate well on P(LA-co-GA-co-MMD) scaffolds and, consequently, form a cell monolayer fully covering on the scaffold surface. Furthermore, the P(LA-co-GA-co-MMD) scaffolds benefit to excellent cell infiltration after subcutaneous implantation. These results indicated that the P(LA-co-GA-co-MMD) nanofibrous scaffolds could be potential candidates for vascular tissue engineering.

Hyaluronic acid/EDC/NHS-crosslinked green electrospun silk fibroin nanofibrous scaffolds for tissue engineering

The mechanical properties of SF nanofibrous matrices were enhanced through crosslinking with HA/EDC/NHS for soft tissue engineering.

Facile method for fabricating uniformly patterned and porous nanofibrous scaffolds for tissue engineering

Electrospinning is a technique that has been widely utilized to create nanofibrous scaffolds that mimic the cellular environment. Scaffold fabrication using the conventional electrospinning technique is cost-effective and simple. However, this method is slightly problematic in terms of creating a well-defined structure. To create a uniformly patterned and porous nanofibrous scaffold, in this study, we utilized an easy module consisting of a patterned watersoluble film placed on the top of a conventional collector. Scaffolds fabricated with either poly(lactide-co-glycolide) (PLGA) or poly(e-caprolactone) (PCL) were seeded with human adipose-derived stem cells (hASCs), and evaluated for cellular proliferation. The patterned and porous nanofibrous scaffolds facilitated significantly better hASC proliferation compared to scaffolds prepared using a conventional collector apparatus. Enhanced hASC proliferation was confirmed by total cellular proliferation activity evaluation and scanning electron microscopy (SEM). These results indicate that the facile method described in this study would be promising for preparation of patterned and porous nanofibrous scaffolds for a variety of tissue engineering applications. Open image in new window

Effect of nanofiber content on bone regeneration of silk fibroin/poly(ε-caprolactone) nano/microfibrous composite scaffolds.

The broad application of electrospun nanofibrous scaffolds in tissue engineering is limited by their small pore size, which has a negative influence on cell migration. This disadvantage could be significantly improved through the combination of nano- and microfibrous structure. To accomplish this, different nano/microfibrous scaffolds were produced by hybrid electrospinning, combining solution electrospinning with melt electrospinning, while varying the content of the nanofiber. The morphology of the silk fibroin (SF)/poly(ε-caprolactone) (PCL) nano/microfibrous composite scaffolds was investigated with field-emission scanning electron microscopy, while the mechanical and pore properties were assessed by measurement of tensile strength and mercury porosimetry. To assay cell proliferation, cell viability, and infiltration ability, human mesenchymal stem cells were seeded on the SF/PCL nano/microfibrous composite scaffolds. From in vivo tests, it was found that the bone-regenerating ability of SF/PCL nano/microfibrous composite scaffolds was closely associated with the nanofiber content in the composite scaffolds. In conclusion, this approach of controlling the nanofiber content in SF/PCL nano/microfibrous composite scaffolds could be useful in the design of novel scaffolds for tissue engineering.

Advancements in Electrospinning of Polymeric Nanofibrous Scaffolds for Tissue Engineering

Polymeric nanofibers have potential as tissue engineering scaffolds, as they mimic the nanoscale properties and structural characteristics of native extracellular matrix (ECM). Nanofibers composed of natural and synthetic polymers, biomimetic composites, ceramics, and metals have been fabricated by electrospinning for various tissue engineering applications. The inherent advantages of electrospinning nanofibers include the generation of substrata with high surface area-to-volume ratios, the capacity to precisely control material and mechanical properties, and a tendency for cellular in-growth due to interconnectivity within the pores. Furthermore, the electrospinning process affords the opportunity to engineer scaffolds with micro- to nanoscale topography similar to the natural ECM. This review describes the fundamental aspects of the electrospinning process when applied to spinnable natural and synthetic polymers; particularly, those parameters that influence fiber geometry, morphology, mesh porosity, and scaffold mechanical properties. We describe cellular responses to fiber morphology achieved by varying processing parameters and highlight successful applications of electrospun nanofibrous scaffolds when used to tissue engineer bone, skin, and vascular grafts.

Starting with Form, Emerging with Function: Nanofibrous Scaffolds for Tissue Engineering of Orthopedic Tissues

Starting with Form, Emerging with Function: Nanofibrous Scaffolds for Tissue Engineering of Orthopedic Tissues

Self-Assembling Peptide Nanofibrous Scaffolds for Tissue Engineering: Novel Approaches and Strategies for Effective Functional Regeneration

Tissue engineering requires an ideal scaffold that will aid in the regeneration of the damaged tissues both structurally and functionally. Conventionally, polymeric nanofibrous scaffolds have been extensively used due to their structural similarity to the native extracellular matrix. Thus far, top-down approaches like electrospinning and phase separation have been predominantly used for the nanofiber fabrication. Recently, self-assembling peptide nanofibers (SAPNF) have been identified as promising scaffolds for tissue engineering applications. Molecular self-assembly of peptides, which is a bottom-up approach has laid foundations for the development of such novel scaffolds. Designer self-assembling peptides provide functional support as well as bio-recognition due to the presence of bioactive motifs embedded in them. However, there are certain limitations to both electrospun and SAPNF scaffolds in terms of synthesis, cues presented to the biological system and applications. Design of composite, hybrid scaffolds by super-positioning possible cues may result in effective functional tissue regeneration at multiple levels.