An ideal extracellular matrix (ECM) replacement scaffold in a three-dimensional cell (3D) culture should induce in vivo-like interactions between the ECM and cultured cells. Highly hydrophilic polyvinyl alcohol (PVA) nanofibers disintegrate upon contact with water, resulting in the loss of their fibrous morphology in cell cultures. This can be resolved by using chemical crosslinkers and post-crosslinking. A crosslinked, water-stable, porous, and optically transparent PVA nanofibrous membrane (NM) supports the 3D growth of various cell types. The binding of cells attached to the porous PVA NM is low, resulting in the aggregation of cultured cells in prolonged cultures. PVA NMs containing integrin-binding peptides of fibronectin and laminin were produced to retain the blended peptides as cell-binding substrates. These peptide-blended PVA NMs promote peptide-specific cell adherence and growth. Various cells, including epithelial cells, cultured on these PVA NMs form layers instead of cell aggregates and spheroids, and their growth patterns are similar to those of the cells cultured on an ECM-coated PVA NM. The peptide-retained PVA NMs are non-stimulatory to dendritic cells cultured on the membranes. These peptide-retaining PVA NMs can be used as an ECM replacement matrix by providing in vivo-like interactions between the matrix and cultured cells.
- Publication type
- Journal Article MeSH
Electrospinning is a widely employed manufacturing platform for tissue engineering applications because it produces structures that closely mimic the extracellular matrix. Herein, we demonstrate the potential of poly(vinyl alcohol) (PVA) electrospun nanofibers as scaffolds for tissue engineering. Nanofibers were created by needleless direct current electrospinning from PVA with two different degrees of hydrolysis (DH), namely 98% and 99% and subsequently heat treated at 180 °C for up to 16 h to render them insoluble in aqueous environments without the use of toxic cross-linking agents. Despite the small differences in the PVA chemical structure, the changes in the material properties were substantial. The higher degree of hydrolysis resulted in non-woven supports with thinner fibres (285 ± 81 nm c.f. 399 ± 153 nm) that were mechanically stronger by 62% (±11%) and almost twice as more crystalline than those from 98% hydrolysed PVA. Although prolonged heat treatment (16 h) did not influence fibre morphology, it reduced the crystallinity and tensile strength for both sets of materials. All samples demonstrated a lack or very low degree of haemolysis (<5%), and there were no notable changes in their anticoagulant activity (≤3%). Thrombus formation, on the other hand, increased by 82% (±18%) for the 98% hydrolysed samples and by 71% (±10%) for the 99% hydrolysed samples, with heat treatment up to 16 h, as a direct consequence of the preservation of the fibrous morphology. 3T3 mouse fibroblasts showed the best proliferation on scaffolds that were thermally stabilised for 4 and 8 h. Overall these scaffolds show potential as 'greener' alternatives to other electrospun tissue engineering materials, especially in cases where they may be used as delivery vectors for heat tolerant additives.
- Publication type
- Journal Article MeSH
Nanofibrous materials produced from natural polymers have wide range of potential uses in regenerative medicine. This paper focuses on preparation of nanofibrous layers produced from intentionally hydrophobized derivatives of hyaluronan, which is known for its ability to promote wound healing. This structural modification of hyaluronan expands the range of potential uses of this promising material, which is otherwise limited due to the hydrophilic nature of hyaluronic acid. The aim of this research was preparation of nanofibrous material that would retain its fibrous structure and dimensional stability even after getting into contact with an aqueous medium, which is impossible to achieve with layers composed solely of native hyaluronan. As a result, such material would be able to retain its breathability and good mechanical properties when both dry and wet. Furthermore, all prepared materials were proved non-toxic for cells. This self-supporting nanofibrous matrix can be used as a scaffold, or porous wound dressing.
- Publication type
- Journal Article MeSH
An ideal decellularized allogenic or xenogeneic cardiovascular graft should be capable of preventing thrombus formation after implantation. The antithrombogenicity of the graft is ensured by a confluent endothelial cell layer formed on its surface. Later repopulation and remodeling of the scaffold by the patient's cells should result in the formation of living autologous tissue. In the work presented here, decellularized porcine pericardium scaffolds were modified by growing a fibrin mesh on the surface and inside the scaffolds, and by attaching heparin and human vascular endothelial growth factor (VEGF) to this mesh. Then the scaffolds were seeded with human adipose tissue-derived stem cells (ASCs). While the ASCs grew only on the surface of the decellularized pericardium, the fibrin-modified scaffolds were entirely repopulated in 28 d, and the scaffolds modified with fibrin, heparin and VEGF were already repopulated within 6 d. Label free mass spectrometry revealed fibronectin, collagens, and other extracellular matrix proteins produced by ASCs during recellularization. Thin layers of human umbilical endothelial cells were formed within 4 d after the cells were seeded on the surfaces of the scaffold, which had previously been seeded with ASCs. The results indicate that an artificial tissue prepared by in vitro recellularization and remodeling of decellularized non-autologous pericardium with autologous ASCs seems to be a promising candidate for cardiovascular grafts capable of accelerating in situ endothelialization. ASCs resemble the valve interstitial cells present in heart valves. An advantage of this approach is that ASCs can easily be collected from the patient by liposuction.
- MeSH
- Bioprosthesis MeSH
- Decellularized Extracellular Matrix chemistry MeSH
- Human Umbilical Vein Endothelial Cells MeSH
- Endothelial Cells cytology MeSH
- Extracellular Matrix metabolism MeSH
- Fibrinogen chemistry MeSH
- Fibronectins chemistry MeSH
- Microscopy, Fluorescence MeSH
- Stem Cells MeSH
- Collagen chemistry MeSH
- Humans MeSH
- Lipectomy MeSH
- Pericardium metabolism pathology MeSH
- Swine MeSH
- Cell Proliferation MeSH
- Heart Valves * MeSH
- In Vitro Techniques MeSH
- Tissue Engineering methods MeSH
- Tissue Scaffolds * chemistry MeSH
- Thrombin chemistry MeSH
- Adipose Tissue cytology MeSH
- Vascular Endothelial Growth Factor A metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The effectiveness of cell transplantation can be improved by optimization of the transplantation site. For some types of cells that form highly oxygen-demanding tissue, e.g., pancreatic islets, a successful engraftment depends on immediate and sufficient blood supply. This critical point can be avoided when cells are transplanted into a bioengineered pre-vascularized cavity which can be formed using a polymer scaffold. In our study, we tested surface-modified poly(lactide-co-caprolactone) (PLCL) capsular scaffolds containing the pro-angiogenic factor VEGF. After each modification step (i.e., amination and heparinization), the surface properties and morphology of scaffolds were characterized by ATR-FTIR and XPS spectroscopy, and by SEM and AFM. All modifications preserved the gross capsule morphology and maintained the open pore structure. Optimized aminolysis conditions decreased the Mw of PLCL only up to 10% while generating a sufficient number of NH2 groups required for the covalent immobilization of heparin. The heparin layer served as a VEGF reservoir with an in vitro VEGF release for at least four weeks. In vivo studies revealed that to obtain highly vascularized PLCL capsules (a) the optimal VEGF dose for the capsule was 50 μg and (b) the implantation time was four weeks when implanted into the greater omentum of Lewis rats; dense fibrous tissue accompanied by vessels completely infiltrated the scaffold and created sparse granulation tissue within the internal cavity of the capsule. The prepared pre-vascularized pouch enabled the islet graft survival and functioning for at least 50 days after islet transplantation. The proposed construct can be used to create a reliable pre-vascularized pouch for cell transplantation.
- MeSH
- Bioengineering * MeSH
- Diabetes Mellitus, Experimental chemically induced metabolism pathology MeSH
- Neovascularization, Physiologic * MeSH
- Injections, Intraperitoneal MeSH
- Blood Glucose analysis MeSH
- Rats MeSH
- Molecular Structure MeSH
- Polyesters chemistry metabolism MeSH
- Rats, Inbred Lew MeSH
- Streptozocin administration & dosage MeSH
- Capsules chemistry metabolism MeSH
- Islets of Langerhans Transplantation * MeSH
- Vascular Endothelial Growth Factors chemistry metabolism MeSH
- Particle Size MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Vitiligo is the most common depigmentation disorder of the skin. Currently, its therapy focuses on the halting of the immune response and stimulation of the regenerative processes, leading to the restoration of normal melanocyte function. Platelet-rich plasma (PRP) represents a safe and cheap regenerative therapy option, as it delivers a wide spectrum of native growth factors, cytokines and other bioactive molecules. The aim of this study was to develop a simple delivery system to prolong the effects of the bioactive molecules released from platelets. The surface of electrospun and centrifugally spun poly-ε-caprolactone (PCL) fibrous scaffolds was functionalized with various concentrations of platelets; the influence of the morphology of the scaffolds and the concentration of the released platelet-derived bioactive molecules on melanocytes, was then assessed. An almost two-fold increase in the amount of the released bioactive molecules was detected on the centrifugally spun vs. electrospun scaffolds, and a sustained 14-day release of the bioactive molecules was demonstrated. A strong concentration-dependent response of melanocyte to the bioactive molecules was observed; higher concentrations of bioactive molecules resulted in improved metabolic activity and proliferation of melanocytes. This simple system improves melanocyte viability, offers on-site preparation and is suitable for prolonged topical PRP administration.
- MeSH
- Drug Delivery Systems * methods MeSH
- Humans MeSH
- Melanocytes MeSH
- Platelet-Rich Plasma * MeSH
- Vitiligo therapy MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The study involved the electrospinning of the copolymer poly(L-lactide-co-ε-caprolactone) (PLCL) into tubular grafts. The subsequent material characterization, including micro-computed tomography analysis, revealed a level of porosity of around 70%, with pore sizes of 9.34 ± 0.19 μm and fiber diameters of 5.58 ± 0.10 μm. Unlike fibrous polycaprolactone, the electrospun PLCL copolymer promoted fibroblast and endothelial cell adhesion and proliferation in vitro. Moreover, the regeneration of the vessel wall was detected following implantation and, after six months, the endothelialization of the lumen and the infiltration of arranged smooth muscle cells producing collagen was observed. However, the degradation rate was found to be accelerated in the rabbit animal model. The study was conducted under conditions that reflected the clinical requirements-the prostheses were sutured in the end-to-side fashion and the long-term end point of prosthesis healing was assessed. The regeneration of the vessel wall in terms of endothelialization, smooth cell infiltration and the presence of collagen fibers was observed after six months in vivo. A part of the grafts failed due to the rapid degradation rate of the PLCL copolymer.
- MeSH
- Aorta pathology MeSH
- Carotid Arteries pathology MeSH
- Cell Adhesion MeSH
- 3T3 Cells MeSH
- Blood Vessel Prosthesis * MeSH
- Human Umbilical Vein Endothelial Cells MeSH
- Endothelial Cells MeSH
- Fibroblasts cytology MeSH
- Collagen metabolism MeSH
- Rabbits MeSH
- Rats MeSH
- Humans MeSH
- Myocytes, Smooth Muscle cytology MeSH
- Mice MeSH
- Polyesters chemistry MeSH
- Polymers chemistry MeSH
- Porosity MeSH
- Swine MeSH
- Dogs MeSH
- Regeneration MeSH
- X-Ray Microtomography MeSH
- Tissue Engineering methods MeSH
- Tissue Scaffolds MeSH
- Vascular Grafting * MeSH
- Imaging, Three-Dimensional MeSH
- Animals MeSH
- Check Tag
- Rabbits MeSH
- Rats MeSH
- Humans MeSH
- Mice MeSH
- Dogs MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
The study describes the detailed examination of the effect of ethylene oxide sterilization on electrospun scaffolds constructed from biodegradable polyesters. Different fibrous layers fabricated from polycaprolactone (PCL) and a copolymer consisting of polylactide and polycaprolactone (PLCL) were investigated for the determination of their mechanical properties, degradation rates and interaction with fibroblasts. It was discovered that the sterilization procedure influenced the mechanical properties of the electrospun PLCL copolymer scaffold to the greatest extent. No effect of ethylene oxide sterilization on degradation behavior was observed. However, a delayed fibroblast proliferation rate was noticed with concern to the ethylene oxide sterilized samples compared to the ethanol sterilization of the materials.
- MeSH
- Biocompatible Materials chemistry metabolism pharmacology MeSH
- Cell Line MeSH
- Blood Vessel Prosthesis MeSH
- Ethylene Oxide chemistry pharmacology MeSH
- Microscopy, Electron, Scanning MeSH
- Elastic Modulus MeSH
- Mice MeSH
- Nanofibers chemistry MeSH
- Tensile Strength MeSH
- Polyesters chemistry metabolism MeSH
- Sterilization MeSH
- Cell Survival drug effects MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Purpose: Incisional hernia repair is an unsuccessful field of surgery, with long-term recurrence rates reaching up to 50% regardless of technique or mesh material used. Various implants and their positioning within the abdominal wall pose numerous long-term complications that are difficult to treat due to their permanent nature and the chronic foreign body reaction they trigger. Materials mimicking the 3D structure of the extracellular matrix promote cell adhesion, proliferation, migration, and differentiation. Some electrospun nanofibrous scaffolds provide a topography of a natural extracellular matrix and are cost effective to manufacture. Materials and methods: A composite scaffold that was assembled out of a standard polypropylene hernia mesh and poly-ε-caprolactone (PCL) nanofibers was tested in a large animal model (minipig), and the final scar tissue was subjected to histological and biomechanical testing to verify our in vitro results published previously. Results: We have demonstrated that a layer of PCL nanofibers leads to tissue overgrowth and the formation of a thick fibrous plate around the implant. Collagen maturation is accelerated, and the final scar is more flexible and elastic than under a standard polypropylene mesh with less pronounced shrinkage observed. However, the samples with the composite scaffold were less resistant to distracting forces than when a standard mesh was used. We believe that the adverse effects could be caused due to the material assembly, as they do not comply with our previous results. Conclusion: We believe that PCL nanofibers on their own can cause enough fibroplasia to be used as a separate material without the polypropylene base, thus avoiding potential adverse effects caused by any added substances.
- MeSH
- Abdominal Wall surgery MeSH
- Surgical Mesh * MeSH
- Hernia * MeSH
- Collagen metabolism MeSH
- Swine, Miniature MeSH
- Disease Models, Animal MeSH
- Mice MeSH
- Nanofibers chemistry MeSH
- Herniorrhaphy instrumentation methods MeSH
- Polyesters MeSH
- Polypropylenes chemistry MeSH
- Swine MeSH
- Materials Testing MeSH
- Tissue Scaffolds chemistry MeSH
- Animals MeSH
- Check Tag
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Biodegradable polyesters, namely polycaprolactone (PCL) and copolymer of polylactide and polycaprolactone (PLCL) were electrospun into various fibrous structures and their hemocompatibility was evaluated in vitro. Firstly, hemolytic effect was evaluated upon incubation with diluted whole blood. The results showed that the degree of hemolysis depended on chemical composition and fibrous morphology. Electrospun polycaprolactone induced slight degree of hemolysis depending on its molecular weight and fibrous morphology; copolymer PLCL did not cause detectable hemolysis. The influence of coagulation pathways was examined by measurement of coagulation times. It was showed that intrinsic coagulation pathway assessed by activated partial thromboplastin time (APTT) was moderately accelerated after incubation with PCL and prolonged after incubation with copolymer PLCL. Extrinsic activation of coagulation tested by prothrombin time (PT) was slightly accelerated after incubation with all tested electrospun samples. Thrombogenicity assessment of fibrous samples revealed high thrombogenic properties of fibrous materials that was comparable to high degree of collagen thrombogenicity. The level of platelet activation was dependent on chemical composition and surface morphology of tested materials.
- MeSH
- Biocompatible Materials chemical synthesis chemistry pharmacology MeSH
- Hemolysis drug effects MeSH
- Collagen chemistry MeSH
- Blood Cells cytology drug effects metabolism MeSH
- Humans MeSH
- Microscopy, Electron, Scanning MeSH
- Partial Thromboplastin Time MeSH
- Polyesters chemistry MeSH
- Polymers chemical synthesis chemistry MeSH
- Prothrombin Time MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
