Small Diameter Vascular Scaffolds Research Articles

Design and preparation of an artificial vascular scaffold with internal surface modification.

Advances in regeneration methods have brought us improved vascular scaffolds with small diameters (φ < 6 mm) for enhancing biological suitability that solve their propensity for causing intimal hyperplasia post-transplantation. The correlation between the rehydration ratio of the hydrogel and its material concentration is obtained by adjusting the material ratio of the hydrogel solution. The vascular model with helical structure has been established and analyzed to verify the effect of helical microvascular structure on thrombosis formation by the fluid simulation methods. Then, the helical structure vascular has been fabricated by self-developed 3D bioprinter, the vascular scaffolds are freeze-dried and rehydrated in polyethylene glycol (PEG) solution. The experimental results showed that the hybrid hydrogel had a qualified rehydration ratio when the content of gelatin, sodium alginate, and glycerol was 5, 6, and 3 wt%. The established flow channel model can effectively reduce thrombus deposition and improve long-term patency ratio. After PEG solution modification, the contact angle of the inner wall of the vascular scaffold was less than 30°, showing better hydrophilic characteristics. In study, a small-diameter inner wall vascular scaffold with better long-term patency was successfully designed and prepared by wrinkling and PEG modification of the inner wall of the vascular scaffold. This study not only creates small-diameter vascular scaffolds with helical structure that improves the surface hydrophilicity to reduce the risk of thrombosis but also rekindles confidence in the regeneration of small caliber vascular structures.

Electrospun gelatin-based biomimetic scaffold with spatially aligned and three-layer architectures for vascular tissue engineering

The spatial cellular alignment and multi-layer structure are vitally important for the physiological functions of natural blood vessels. However, the two features are difficult to be constructed in one scaffold simultaneously, especially in the small-diameter vascular scaffold. Here we report a general strategy to construct a gelatin-based biomimetic three-layer vascular scaffold with spatial alignment features mimicking the natural structure of blood vessels. By using a sequential electrospinning strategy combined with folding and rolling manipulation, a three-layer vascular scaffold with inner and middle layers spatially perpendicular to each other was obtained. The special features of this scaffold could fully mimic the natural multi-layer structures of blood vessels and also possess great potential for spatial arrangement guidance of corresponding cells in blood vessels.

Fabrication Process of Triple-Layer Small-Diameter Vascular Scaffold with Microchannel Structure in the Inner Layer for Accelerated Endothelialization

Fabrication Process of Triple-Layer Small-Diameter Vascular Scaffold with Microchannel Structure in the Inner Layer for Accelerated Endothelialization

Effects of Chemical Composition on the Shape Memory Property of Poly(dl-lactide-co-trimethylene carbonate) as Self-Morphing Small-Diameter Vascular Scaffolds.

Smart materials have great potential in many biomedical applications, in which biodegradable shape memory polymers (SMPs) can be used as surgical sutures, implants, and stents. Poly(dl-lactide-co-trimethylene carbonate) (PDLLTC) represents one of the promising SMPs and is widely used in biomedical applications. However, the relationship between its shape memory property and chemical structure has not been fully studied and needs further elaboration. In this work, PDLLTC copolymers in different compositions have been synthesized, and their shape memory properties have been investigated. It has been found that the shape memory property is related to the chemical composition and polymeric chain segments. The copolymer with a DLLA/TMC ratio of 75:25 (PDLLTC7525) has been demonstrated with great shape fixation and recovery ratio at human body temperature. Furthermore, PDLLTC7525-based self-morphing small-diameter vascular scaffolds adhered with inner electrospun aligned gelatin/hyaluronic acid (Gel/HA) nanofibers have been constructed, as a merit of its shape memory property. The scaffolds have been demonstrated to facilitate the proliferation and adhesion of endothelial cells on the inner layer. Therefore, PDLLTC with tailorable shape memory properties represents a promising candidate for the development of SMPs, as well as for small-diameter vascular scaffolds construction.

Near-field electrospinning of polydioxanone small diameter vascular graft scaffolds

The ideal “off the shelf” tissue engineering, small-diameter (SD) vascular graft hinges on designing a scaffold to act as a template that facilitates transmural ingrowth of capillaries to regenerate an endothelized neointimal surface. Towards this goal, we explored two types of near-field electrospun (NFES) polydioxanone (PDO) architectures, as SD vascular graft scaffolds. The first architecture type consisted of a 200 × 200 μm and 500 × 500 μm grid geometry with random fiber infill, while the second architecture consisted of aligned fibers written in a 45°/45° and 20°/70° offset from the long axis written, both on a 4 mm diameter cylindrical mandrel. These vascular graft scaffolds were evaluated for their effective pore size, mechanical properties, and platelet-material interactions compared to traditionally electrospun (TES) scaffolds and Gore-Tex® vascular grafts. It was found that effective pore size, given by 9.9 and 97 μm microsphere filtration through the scaffold wall for NFES scaffolds, was significantly more permeable compared to TES scaffolds and Gore-Tex® vascular grafts. Furthermore, ultimate tensile strength, percent elongation, suture retention, burst pressure, and Young's modulus were all tailorable compared to TES scaffold characterization. Lastly, platelet adhesion was attenuated on NFES scaffolds compared to TES scaffold which approximates the low level of platelet adhesion measured on Gore-Tex®, with all samples showing minimal platelet activation given by P-selectin surface expression. Together, these results suggest a highly tailorable process for the creation of the next generation of small-diameter vascular grafts.

Cyclopeptide-β-cyclodextrin/γ-glycerol methoxytrimethoxysilane film for potential vascular tissue engineering scaffolds

The mortality rate of cardiovascular diseases is the highest among all mortality rates worldwide. Allotransplantation and autotransplantation are limited by rejection reaction and availability. Tissue engineering provides new avenues for the treatment of cardiovascular diseases. However, the current small-diameter (<6 mm) vascular tissue-engineered scaffolds have many challenges, including thrombosis, stenosis, and infection. Small-diameter vascular scaffolds have structural and compositional requirements such as biocompatibility, porosity, and appropriate phase separation. We used liquid-crystal cyclopeptide（CYC）to modify β-cyclodextrin and mixed it with γ-glycerol methoxytrimethoxysilane (GPTMS) to prepare CYC-β-cyclodextrin (βCD)/GPTMS film by sol-gel. The chemical structure of CYC-βCD was confirmed by Fourier transform infrared spectroscopy and 1H-nuclear magnetic resonance. The chemical characterization of CYC-βCD/GPTMS film was performed by differential scanning calorimetry, X-ray diffraction, and small-angle X-ray scattering. The surface morphology and phase separation microstructure of the film were determined by scanning electron microscopy and atomic force microscopy, and the image of polarizing microscopy showed the liquid-crystal structure of the film. Cell culture experiments showed that CYC-βCD/GPTMS film had good cytocompatibility and induced growth and proliferation of cells. These results indicated the potential applications of CYC-βCD/GPTMS film in tissue engineering scaffolds.

Tissue engineered bovine saphenous vein extracellular matrix scaffolds produced via antigen removal achieve high in vivo patency rates

Diseases of small diameter blood vessels encompass the largest portion of cardiovascular diseases, with over 4.2 million people undergoing autologous vascular grafting every year. However, approximately one third of patients are ineligible for autologous vascular grafting due to lack of suitable donor vasculature. Acellular extracellular matrix (ECM) scaffolds derived from xenogeneic vascular tissue have potential to serve as ideal biomaterials for production of off-the-shelf vascular grafts capable of eliminating the need for autologous vessel harvest. A modified antigen removal (AR) tissue process, employing aminosulfabetaine-16 (ASB-16) was used to create off-the-shelf small diameter (< 3 mm) vascular graft from bovine saphenous vein ECM scaffolds with significantly reduced antigenic content, while retaining native vascular ECM protein structure and function. Elimination of native tissue antigen content conferred graft-specific adaptive immune avoidance, while retention of native ECM protein macromolecular structure resulted in pro-regenerative cellular infiltration, ECM turnover and innate immune self-recognition in a rabbit subpannicular model. Finally, retention of the delicate vascular basement membrane protein integrity conferred endothelial cell repopulation and 100% patency rate in a rabbit jugular interposition model, comparable only to Autograft implants. Alternatively, the lack of these important basement membrane proteins in otherwise identical scaffolds yielded a patency rate of only 20%. We conclude that acellular antigen removed bovine saphenous vein ECM scaffolds have potential to serve as ideal off-the-shelf small diameter vascular scaffolds with high in vivo patency rates due to their low antigen content, retained native tissue basement membrane integrity and preserved native ECM structure, composition and functional properties. Statement of significanceThe use of autologous vessels for the treatment of small diameter vascular diseases is common practice. However, the use of autologous tissue poses significant complications due to tissue harvest and limited availability. Developing an alternative vessel for use for the treatment of small diameter vessel diseases can potentially increase the success rate of autologous vascular grafting by eliminating complications related to the use of autologous vessel and increased availability. This manuscript demonstrates the potential of non-antigenic extracellular matrix (ECM) scaffolds derived from xenogeneic vascular tissue as off-the-shelf vascular grafts for the treatment of small diameter vascular diseases.

Small diameter polycaprolactone vascular grafts are patent in sheep carotid bypass but require antithrombotic therapy.

Background: Polycaprolactone (PCL) scaffolds exhibit high biocompatibility and are attractive as vascular conduits. Materials & methods: PCL tubes were cultivated in bioreactor with human adipose regenerative cellsto assess ex vivo cytocompatibility, whereas in vivo PCL tube patency was evaluated in sheep carotid bypass with and without antithrombotic treatment. Results:Ex vivo results revealed increasing adipose regenerative cells on PCL using dynamic bioreactor culturing. In vivo data showed that 67% (2/3) of grafts in the antithrombotic group were patent at day 28, while 100% (3/3) of control grafts were occluded already during the first week due to thrombosis. Histology showed that patent PCL grafts were recellularized by host cells. Conclusion: PCL tubes may work as small diameter vascular scaffolds under antithrombotic treatment.

Fabrication and assessment of chondroitin sulfate-modified collagen nanofibers for small-diameter vascular tissue engineering applications

Chondroitin sulfate (ChS) has shown promising results in promoting cell proliferation and antithrombogenic activity. To engineered develop a dual-function vascular scaffold with antithrombosis and endothelialization, ChS was tethered to collagen to accelerate the growth of endothelial cells and prevent platelet activation. First, ChS was used to conjugate with collagen to generate glycosylated products (ChS-COL) via reductive amination. Then, the fabricated ChS-COL conjugates were electrospun into nanofibers and their morphologies and physicochemical characteristics, cell-scaffold responses and platelet behaviors upon ChS-COL nanofibers were comprehensively characterized to evaluate their potential use for small-diameter vascular tissue-engineered scaffolds. The experimental results demonstrated that the ChS modified collagen electrospun nanofibers were stimulatory of endothelial cell behavior, alleviated thrombocyte activation and maintained an antithrombotic effect in vivo in 10-day post-transplantation. The ChS-COL scaffolds encouraged rapid endothelialization, thus probably ensuring the antithrombotic function in long-term implantation, suggesting their promise for small-diameter vascular tissue engineering applications.

Tissue Engineered Bovine Saphenous Vein Extracellular Matrix Scaffolds Produced Via Antigen Removal Achieve High &lt;i&gt;In Vivo&lt;/i&gt; Patency Rates

Diseases of small diameter blood vessels encompass the largest portion of cardiovascular diseases, with over 4.2 million people undergoing autologous vascular grafting every year. However, approximately one third of patients are ineligible for autologous vascular grafting due to lack of suitable donor vasculature. Acellular extracellular matrix (ECM) scaffolds derived from xenogeneic vascular tissue have potential to serve as ideal biomaterials for production of an off-the-shelf vascular graft capable of eliminating the need for autologous vessel harvest. Using the antigen removal tissue processing method an off-the-shelf small diameter (< 3 mm) vascular graft from bovine saphenous vein was produced with significantly reduced antigenic content, while retaining the structure and function of its native vascular ECM proteins. Elimination of native tissue antigen content conferred graft-specific adaptive immune avoidance. Retention of native ECM protein macromolecular structure, as assessed by collagen polarization, resulted in pro-regenerative cellular infiltration, ECM turnover and innate immune self-recognition. Finally, retention of the delicate vascular basement membrane protein integrity conferred endothelial cell repopulation and 100% patency rate in a rabbit jugular interposition model, comparable only to Autograft implants. Alternatively, the lack of these important basement membrane proteins in otherwise identical scaffolds yielded a patency rate of only 20%. We conclude that acellular antigen removed bovine saphenous vein ECM scaffolds have potential to serve as ideal off-the-shelf small diameter vascular scaffolds with high in vivo patency rates due to their low antigen content, retained native tissue basement membrane integrity and preserved native ECM structure, composition and functional properties.

Three-dimensional silk fibroin microsphere-nanofiber scaffolds for vascular tissue engineering

A significant limitation in the engineering of artificial small-diameter vascular scaffolds is that the number of endothelial cells (ECs) is not sufficient to generate a confluent coverage of the vascular scaffolds, so that the surfaces of vascular scaffolds form thrombus via platelet adhesion and aggregation. Thrombus decrease relies on three-dimensional (3D) scaffolds to mimic the natural extracellular matrix (ECM) as templates to regulate cell behavior and facilitate tissue maturation. Here, we developed 3D scaffolds consisting of silk fibroin (SF) nanofibers and homogeneous microspheres by electrospinning and microfluidics. The nanofibers with diameters ranging from 250 to 350 ​nm doped with microspheres (2–10 ​μm) formed bridge-shaped structures. ECs were seeded and maintained on the 3D microsphere-nanofiber scaffolds with a mean fiber diameter of 300 ​nm. A 10% higher ratio of cell proliferation on 3D microsphere-nanofiber SF scaffolds was noted as compared to that on microporous and sponge-like SF scaffolds with small surface network fabricated by freeze-drying. Moreover, the gene transcript levels including CD146, VE-C and PECAM-1 were better preserved on 3D microsphere-nanofiber SF scaffolds than those on freeze-dried scaffolds. Thus, the developed 3D microsphere-nanofiber structure may have a myriad of applications in vascular tissue engineering scaffolds and cardiovascular devices.

Effect of corrugated structure on the collapsing of the small-diameter vascular scaffolds.

Major barriers to the development of a desirable small-diameter vascular scaffold are the compliance mismatch between natural and artificial vessels and low long-term patency. In the present study,...

Temperature Responsive Shape-Memory Scaffolds with Circumferentially Aligned Nanofibers for Guiding Smooth Muscle Cell Behavior.

Structural simulation of the smooth muscle layer plays an important role in tissue engineering of blood vessels for the replacement of damaged arteries. However, it is difficult to construct small-diameter tubular scaffolds to homogenously locate and align smooth muscle cells (SMCs). In this work, novel temperature responsive shape-memory scaffolds are designed for SMC culturing. The scaffolds are composed of an outer layer of poly(lactide-glycolide-trimethylene carbonate) (PLGATMC) for programming the deformation from planar to small-diameter tubular shape and an inner layer of aligned nanofibrous membrane of poly(lactide-glycolide)/chitosan (PLGA/CS) to regulate cell adhesion, proliferation, and morphology. The SMC behaviors and functions are dependent on the PLGA/CS ratios of membranes, and the scaffold with PLGA/CS 7:3 membrane exhibits the most suitable ability to regulate SMC behavior. The PLGA/CS@PLGATMC scaffold can be deformed into a temporary planar at 20 °C for convenient seeding and attachment of SMCs and then immediately self-rolled into 3D tube at 37 °C. The proposed strategy offers a practical approach for the development of small-diameter vascular scaffolds from 2D planar into 3D tubular shape by self-rolling.

Small Diameter Xenogeneic Extracellular Matrix Scaffolds for Vascular Applications.

Currently, despite the success of percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG) remains among the most commonly performed cardiac surgical procedures in the United States. Unfortunately, the use of autologous grafts in CABG presents a major clinical challenge as complications due to autologous vessel harvest and limited vessel availability pose a significant setback in the success rate of CABG surgeries. Acellular extracellular matrix (ECM) scaffolds derived from xenogeneic vascular tissues have the potential to overcome these challenges, as they offer unlimited availability and sufficient length to serve as "off-the-shelf" CABGs. Unfortunately, regardless of numerous efforts to produce a fully functional small diameter xenogeneic ECM scaffold, the combination of factors required to overcome all failure mechanisms in a single graft remains elusive. This article covers the major failure mechanisms of current xenogeneic small diameter vessel ECM scaffolds, and reviews the recent advances in the field to overcome these failure mechanisms and ultimately develop a small diameter ECM xenogeneic scaffold for CABG. Impact Statement Currently, the use of autologous vessel in coronary artery bypass graft (CABG) is common practice. However, the use of autologous tissue poses significant complications due to tissue harvest and limited availability. Developing an alternative vessel for use in CABG can potentially increase the success rate of CABG surgery by eliminating complications related to the use of autologous vessel. However, this development has been hindered by an array of failure mechanisms that currently have not been overcome. This article describes the currently identified failure mechanisms of small diameter vascular xenogeneic extracellular matrix scaffolds and reviews current research targeted to overcoming these failure mechanisms toward ensuring long-term graft patency.

Development of double porous poly (ε - caprolactone)/chitosan polymer as tissue engineering scaffold.

Polymer blend made from poly(ε - caprolactone)/chitosan (PCL/CHT) offers interesting opportunities for biological applications. The paper presents a new way to fabricate PCL/CHT double-porosity (macrovoids with interconnected microporosity) membrane materials from a chemical optimization of the solvent and non-solvent phases and from a modified phase inversion technique. By varying the PCL/CHT proportion, it is shown that it is possible to improve the chemical and physical properties of the CHT carbohydrate polymer. The PCL/CHT membranes are fully characterized in term of physico-chemical properties (ATR-FTIR, XRD and DSC) to understand the miscibility of the two-polymer blend. Morphological characterization by SEM shows that by increasing CHT wt% in the blend, the size of the macrovoids was increasing. Rapid enzymatic degradation of PCL from all the blend was found by using lipase (from P. cepacia). The mechanisms at the origin of the morphological structuration of the material is also discussed. To test the ability to operate these materials as small diameter vascular scaffolds, cell culture with human umbilical vein endothelial cells (HUVECs) were carried out on the membrane and the results analyzed with laser scanning confocal microscopy (LSCM). Data suggest that the blend membrane with higher concentration of CHT polymer wt% have suitable properties that promote high number of cells on the surface by maintaining cellular cytoskeleton integrity within 3 days. The blend membrane with a double porous morphology could be potentially applicable in future for small diameter vascular graft application. The surface macrovoids (20-90 μm) could be useful for three-dimensional cellular adhesion and proliferation and interconnected microporous spongy network (7-20 μm) is expected to transfer essential nutrients, oxygen, growth factor between the macrovoids and the supernatant.

Fabrication of hydrophilic small diameter vascular foam scaffolds of poly(ε-caprolactone)/polylactic blend by sodium hydroxide solution

Small diameter (diameter < 6 mm) vascular scaffolds lead to increased hemodynamic disturbances and thrombogenic complications which challenged the material scientists. A compatible interface with applicable mechanical properties of scaffolds is the key issue. In this study, 4 mm inner-diameter poly(ε-caprolactone)/polylactic (PCL/PLA) blend foam vascular scaffolds were fabricated by supercritical carbon dioxide via batch foaming. A uniform open-cell morphology on the cross section of PCL/PLA foams was achieved. To improve the porosity and hydrophilicity on the surface of scaffolds, sodium hydroxide solution was used to hydrolyze off PLA phase. Tensile properties, suture retention, bursting resistance and cell culture of PCL/PLA foam scaffolds were also improved and showed a great promise for vascular tissue engineering application.

Design and Fabrication of a Biomimetic Vascular Scaffold Promoting in Situ Endothelialization and Tunica Media Regeneration.

Multilayered vascular scaffolds may be considered advantageous in regenerating vascular tissues due to the nature of mimicking the native structure of a blood vessel. However, there are currently limited small-diameter vascular scaffolds integrating the specific features of native tunica intima (anti-thrombus and rapid endothelialization) and tunica media (the alignment and ingrowth of smooth muscle cells (SMCs), structural elements capable of promoting vascular regeneration and function). To address this limitation, we developed a modified electrospinning method capable of fabricating a bilayer vascular scaffold with a 2-mm inner diameter and investigated the in vivo performance and regenerative capacity using a rat abdominal aorta, with a 2-month implantation period. The vascular scaffold was fabricated from poly(l-lactide-co-caprolactone)/collagen (PLCL/COL) nanofibers and nanofiber yarns, comprising the luminal and medial layers, respectively. Heparin and anti-CD133 antibody (HEP/CD133) were incorporated into the PLCL/COL nanofibers comprising the luminal layer. The mechanical characterizationdemonstrated compliance of the bilayer scaffold, which was comparable to the human saphenous vein and improved over commercially available e-PTFE grafts. The incorporated components (HEP/CD133) were released over a period of nearly 40 days, during which the nanofibers and nanofiber yarns maintained their structure. Moreover, the released heparin contributed to lumen anticoagulation functionality initially, and the incorporated anti-CD133 antibody promoted the development of a neo-intima. In addition, SMCs proliferated and penetrated throughout the entire nanofiber yarn outer structure. In vivo evaluations demonstrated that a monolayer of endothelial cells (CD31 positive), as well as the aligned and infiltrated smooth muscle tissues (α-SMA positive), were regenerated on the inner and outer layers of the fabricated scaffold, respectively, demonstrating the capacity to regenerate structures mimicking native blood vessels. In conclusion, the functionalized bilayer scaffold can be viewed as a promising candidate for in situ vascular tissue regeneration.

Small-diameter vascular graft using co-electrospun composite PCL/PU nanofibers

Small-diameter vascular scaffolds have been developed by a co-electrospinning method using polyethylene terephthalate (PCL) and elastic polytetrafluoroethylene (PU) as biopolymers with long degradation time. Although they possess favorable properties, individually these two polymers do not meet the requirements for the production of synthetic vascular scaffolds. The co-electrospinning method was adopted to develop and mechanically improve the composite PCL/PU vascular scaffolds. The morphological, mechanical and biological properties of these vascular scaffolds were evaluated through scanning electron microscopy, differential scanning calorimetry, Fourier transform infrared spectroscopy, compliance, tensile testing and MTT assay. The in vivo study of the vascular scaffolds was performed by implanting them on rat and sheep models. The compliance of the composite vascular scaffolds improved by up to 43% through an increased percentage of PU from 10%–90%. The obtained UTS of the scaffolds at 10%, 25%, 50%, 75% and 90% of PU were 4.7 ± 0.34, 3.4 ± 0.6, 4.8 ± 0.62, 2.2 ± 0.34 and 4.4 ± 1.9 MPa, respectively. The results of MTT assays indicated that the cell growth on the scaffolds was augmented when compared to the control, from day one to day seven. Mild edema, mild foreign-body granulomatous reaction and mild fibrosis were observed by pathology test as the side effects in the composite scaffold with 50% PCL. Doppler ultrasound and angiography images confirm that no aneurysm, thrombogenesis, neointimal hyperplasia or occlusion exist, and there is complete patency at the end of an eight month investigation. The fabricated composite vascular scaffolds provide appropriate mechanical and biological properties and clinical requirements, indicating their required potential to be applied as a small-diameter vascular graft.

Control of Mechanical Properties of Small Diameter Vascular Scaffolds by Electrospinning Techniques.

Control of Mechanical Properties of Small Diameter Vascular Scaffolds by Electrospinning Techniques.

Manipulating the structure and mechanical properties of thermoplastic polyurethane/polycaprolactone hybrid small diameter vascular scaffolds fabricated via electrospinning using an assembled rotating collector.

The success of blood vessel transplants with vascular scaffolds (VSs) highly depends on their structure and mechanical properties. The fabrication of small diameter vascular scaffolds (SDVSs) mimicking the properties of native blood vessels has been a challenge. Herein, we propose a facile method to fabricate thermoplastic polyurethane (TPU)/polycaprolactone (PCL) hybrid SDVSs via electrospinning using a modified rotating collector. By varying the ratio between the TPU and the PCL, and changing the electrospinning volume, SDVSs with a wavy configuration and different properties could be obtained. Detailed investigation revealed that certain TPU/PCL hybrid SDVSs closely resembled the mechanical behaviors of blood vessels due to the presence of a wavy region and the combination of flexible TPU and rigid PCL, which mimicked the properties of elastin and collagen in blood vessels. The fabricated TPU/PCL SDVSs achieved lumen diameters of 1-3mm, wall thicknesses of 100-570µm, circumferential moduli of 1-6MPa, ultimate strengths of 2-8MPa, over 250% elongation-at-break values, toe regions of 5.3-9.4%, high recoverability, and compliances close to those of human veins. Moreover, these TPU/PCL SDVSs possessed sufficient suture retention strength and burst pressure to fulfill transplantation requirements and maintain normal blood flow. Human endothelial cell culture revealed good biocompatibility of the scaffolds, and cells were able to grow on the inner surface of the tubular scaffolds, indicating promising prospects for use as tissue-engineered vascular grafts.