Tubular Scaffolds Research Articles

Organized Tubular Scaffolds to Build Vascularized Kidney Proximal Tubules

Organized Tubular Scaffolds to Build Vascularized Kidney Proximal Tubules

Electrospun Fiber‐Based Tubular Structures as 3D Scaffolds to Generate In Vitro Models for Small Intestine

AbstractRecently, in vitro models emerge as valuable tools in biomedical research by enabling the investigation of complex physiological processes in a controlled environment, replicating some traits of interest of the biological tissues. This study focuses on the development of tubular polymeric scaffolds, made of electrospun fibers, aimed to generate three‐dimensional (3D) in vitro intestinal models resembling the lumen of the gut. Polycaprolactone (PCL) and polyacrylonitrile (PAN) are used to produce tightly arranged ultrafine fiber meshes via electrospinning in the form of continuous tubular structures, mimicking the basement membrane on which the epithelial barrier is formed. Morphological, physical, mechanical, and piezoelectric properties of the PCL and PAN tubular scaffolds are investigated. They are cultured with Caco‐2 cells using different biological coatings (i.e., collagen, gelatin, and fibrin) and their capability of promoting a compact epithelial layer is assessed. PCL and PAN scaffolds show 42% and 50% porosity, respectively, with pore diameters and size suitable to impede cell penetration, thus promoting an intestinal epithelial barrier formation. Even if both polymeric structures allow Caco‐2 cell adhesion, PAN fiber meshes best suit many requirements needed by this model, including highest mechanical strength upon expansion, porosity and piezoelectric properties, along with the lowest pore size.

Muticomponent Melt‐Electrowritten Vascular Graft to Mimic and Guide Regeneration of Small Diameter Blood Vessels

AbstractCardiovascular disease is a leading cause of morbidity. Current treatments include vessel substitution using autologous/synthetic vascular grafts, but these commonly fail in small diameter applications, largely due to compliance mismatch and clot formation. In this study, a multicomponent vascular graft, that takes inspiration from native vessel architecture, is developed to overcome these limitations. Melt electrowriting (MEW) is used to produce tubular scaffolds with vascular‐mimetic fiber architecture and mechanics, which is combined with a lyophilized fibrinogen matrix with tailored degradation kinetics to generate a hybrid graft. The MEW framework not only contributes to graft mechanics, but also provides contact guidance to direct cell/neotissue orientation and mimic the native tunica media. This construct is further functionalized with heparin, which in combination with the smooth extracellular matrix (ECM) surface, reduced platelet adhesion and clot formation providing a substrate for endothelization, thereby mimicking the function of the intima. Lastly, an outer electrospun layer representing the adventitia is added to improve elasticity and reduce permeability. This graft satisfies ISO implantability requirements, matches the compliance of native vessels, and reestablishes physiological flow with minimal clot formation in a preclinical model. Therefore, this graft represents an innovative off‐the‐shelf alternative to address the unmet clinical need for small‐diameter vascular grafts.

A qualitative exploration and a Fuzzy Delphi validation of high-risk scaffolding tasks and fatigue-related safety behavioural deviation among scaffolders

BackgroundMost construction mishaps were caused by scaffolding incidents despite implementing various safety measures, and the association with human factors like fatigue has been widely reported. This study aims to identify all high-risk task sequences involved during the erection of the most commonly used scaffold; the deviation from the standard protocol led to a substandard fatigue state, followed by content validation using the Fuzzy Delphi Method. MethodsQualitative exploration was conducted via focal group discussions (FGDs) involving 30 certified experts. The findings generated from FGDs were further validated by utilising the Fuzzy Delphi Method (FDM) by consulting 19 experts with extensive practical experience and leadership roles in scaffolding safety. ResultsThe FGDs identified a total of 7 constructs and 50 items for task sequences involved in the tubular scaffold erection, namely construct Instruction (3 items), Preparation (3 items), Foundation (10 items), First Lift (8 items), Working Platform (7 items), Guardrails (5 items) and Second Lift (14 items). In the FDM validation process, the experts' consensus for each construct was fulfilled with a threshold value (d) ≤ 0.2; thus, all constructs were accepted. Experts' consensus for all items achieved an expert agreement of 75 % and above. Items ranking was conducted using average fuzzy numbers. The highest average fuzzy number documented was 0.8, while the lowest was 0.588. None of the items with the lowest ranking was discarded as all items perfectly fulfilled the second prerequisite and obtained excellent experts’ agreement. ConclusionsThe tool generated will help guide the development of a protocol for scaffolding safety management.

Development of a biodegradable prosthesis through tissue engineering, for the organ-replacement or substitution of the extrahepatic bile duct

Introduction and ObjectivesThere are different situations in which an extrahepatic bile duct replacement or substitute is needed, such as initial and localized stages of bile duct cancer, agenesis, stenosis, or bile duct disruption. Materials and MethodsA prosthesis obtained by electrospinning composed of Poly (D,L-lactide-co-glycolide) (PGLA) - Polycaprolactone (PCL) - Gelatin (Gel) was developed, mechanical and biological tests were carried out to evaluate resistance to tension, biocompatibility, biodegradability, cytotoxicity, morphological analysis and cell culture. The obtained prosthesis was placed in the extrahepatic bile duct of 15 pigs with a 2-year follow-up. Liver function tests and cholangioscopy were evaluated during follow-up. ResultsMechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable. The prosthesis implanted in the experimental model allowed cell adhesion, migration, and proliferation, maintaining bile duct permeability without altering liver function tests. Immunohistochemical analysis indicates the presence of biliary epithelium. ConclusionsA tubular scaffold composed of electrospun PGLA-PCL-Gel nanofibers was used for the first time to replace the extrahepatic bile duct in pigs. Mechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable, making it an excellent candidate for use in bile ducts and potentially in other tissue engineering applications.

Surgical Implantation of Single-Staged Tissue-Engineered Urothelial Tubes in a Minipig Model.

Reconstructive surgeries are often challenged by a lack of grafting tissue. In the treatment of urogenital malformations, the conventional solution has been harvesting gastrointestinal tissue for non-orthotopic reconstruction due to its abundance to reestablish normal function in the patient. The clinical outcomes after rearranging native tissues within the body are often associated with significant morbidity; thus, tissue engineering holds specific potential within this field of surgery. Despite substantial advances, tissue-engineered scaffolds have not yet been established as a valid surgical treatment alternative, mainly due to the costly and complex requirements of materials, production, and implantation. In this protocol, we present a simple and accessible collagen-based tubular scaffold embedded with autologous organ-specific tissue particles, designed as a conduit for urinary diversion. The scaffold is constructed during the primary surgical procedure, comprises commonly available surgical materials, and requires conventional surgical skills. Secondly, the protocol describes an animal model designed to evaluate the short-term in vivo outcomes post-implantation, with the possibility of additional variations to the procedure. This publication aims to demonstrate the procedure step-by-step, with special attention to the use of autologous tissue and a tubular form.

Recombinant collagen coating 3D printed PEGDA hydrogel tube loading with differentiable BMSCs to repair bile duct injury

Bile duct injury presents a significant clinical challenge following hepatobiliary surgery, necessitating advancements in the repair of damaged bile ducts is a persistent issue in biliary surgery. 3D printed tubular scaffolds have emerged as a promising approach for the repair of ductal tissues, yet the development of scaffolds that balance exceptional mechanical properties with biocompatibility remains an ongoing challenge. This study introduces a novel, bio-fabricated bilayer bile duct scaffold using a 3D printing technique. The scaffold comprises an inner layer of polyethylene glycol diacrylate (PEGDA) to provide high mechanical strength, and an outer layer of biocompatible, methacryloylated recombinant collagen type III (rColMA) loaded with basic fibroblast growth factor (bFGF)-encapsulated liposomes (bFGF@Lip). This design enables the controlled release of bFGF, creating an optimal environment for the growth and differentiation of bone marrow mesenchymal stem cells (BMSCs) into cholangiocyte-like cells. These cells are instrumental in the regeneration of bile duct tissues, evidenced by the pronounced expression of cholangiocyte differentiation markers CK19 and CFTR. The PEGDA//rColMA/bFGF@Lip bilayer bile duct scaffold can well simulate the bile duct structure, and the outer rColMA/bFGF@Lip hydrogel can well promote the growth and differentiation of BMSCs into bile duct epithelial cells. In vivo experiments showed that the scaffold did not cause cholestasis in the body. This new in vitro pre-differentiated active 3D printed scaffold provides new ideas for the study of bile duct tissue replacement.

Fabrication of a Triple-Layer Bionic Vascular Scaffold via Hybrid Electrospinning.

Tissue engineering aims to develop bionic scaffolds as alternatives to autologous vascular grafts due to their limited availability. This study introduces a novel wet-electrospinning fabrication technique to create small-diameter, uniformly aligned tubular scaffolds. By combining this innovative method with conventional electrospinning, a bionic tri-layer scaffold that mimics the zonal structure of vascular tissues is produced. The inner and outer layers consist of PCL/Gelatin and PCL/PLGA fibers, respectively, while the middle layer is crafted using PCL through Wet Vertical Magnetic Rod Electrospinning (WVMRE). The scaffold's morphology is analyzed using Scanning Electron Microscopy (SEM) to confirm its bionic structure. The mechanical properties, degradation profile, wettability, and biocompatibility of the scaffold are also characterized. To enhance hemocompatibility, the scaffold is crosslinked with heparin. The results demonstrate sufficient mechanical properties, good wettability of the inner layer, proper degradability of the inner and middle layers, and overall good biocompatibility. In conclusion, this study successfully develops a small-diameter tri-layer tubular scaffold that meets the required specifications.

Biomimetic approach to the design of artificial small‑diameter blood vessels

Objective: To create 2-mm diameter multilayer porous tubular scaffolds (PTS) with characteristics that resemble small-diameter native blood vessels in terms of characteristics.Materials and methods. PTS made of polycaprolactone (PCL, MM 80000) with a PCL-made sealing coat/layer with gelatin addition (PCL-gelatin) with a diameter of 2 mm were created by electrospinning (NANON-01A). Bioactive coating was applied to the PTS surface by sequential incubation in solutions of bovine serum albumin, heparin (Hp), and platelet lysate (PL). Cytotoxicity was investigated under conditions of direct contact of PTS with a monolayer of NIH/3T3 mouse fibroblasts. Viability of human umbilical vein endothelial cells (EA.hy926) was evaluated using Live/Dead® Viability/Cytotoxicity Kit. Permeability and blood flow parameters of the PTS implanted in the infrarenal section of the rat aorta were recorded using Doppler imaging.Results. A three-layer PTS construct with an inner diameter of 2 mm was developed. Its inner and outer layers were formed from 0.2 mL of PCL solution, and the middle sealing coat/layer was from 0.5 mL of PCL with addition of 30% (by weight of polymer) gelatin. Introduction of the sealing coat/layer reduced surgical porosity (SP) from 56.2 ± 8.7 mL/(cm2·min) for a single-layer PTS made of pure PCL to 8.9 ± 2.6 mL/(cm2·min) for a three-layer PTS. The resulting PTS demonstrated physicomechanical characteristics similar to those of native blood vessels; it also showed no cytotoxicity. Application of a bioactive coating of Hp and PL allowed for increased in vitro adhesion and proliferation of endothelial cells. The technique of implantation of 10 mm long fragments of three-layer PTS into the infrarenal section of a rat aorta was corrected, thus minimizing blood loss and narrowing the anastomosis site. In an acute experiment, it was proven that the prostheses were patent and that blood flow parameters (systolic and diastolic velocity, resistivity index) were close to the corresponding indicators of native rat aorta.Conclusion. The developed three-layer PTS constructs have low SP and physicomechanical properties close to those of native blood vessels. Bioactive coating improves the in vitro matrix properties of PTS relative to human endothelial cells. At short-term implantation into the aorta of experimental animals, PTS showed no early thrombosis, while blood flow parameters were close to those of native rat aorta. Thus, three-layer PTS with bioactive coating can be used as a scaffold for creation of in situ tissue-engineered construct of a small-diameter blood vessel.

Genipin crosslinking promotes biomechanical reinforcement and pro-regenerative macrophage polarization in bioartificial tubular substitutes

Traumatic nerve injuries are nowadays a significant clinical challenge and new substitutes with adequate biological and mechanical properties are in need. In this context, fibrin-agarose hydrogels (FA) have shown the possibility to generate tubular scaffolds with promising results for nerve repair. However, to be clinically viable, these scaffolds need to possess enhanced mechanical properties. In this line, genipin (GP) crosslinking has demonstrated to improve biomechanical properties with good biological properties compared to other crosslinkers. In this study, we evaluated the impact of different GP concentrations (0.05, 0.1 and 0.2% (m/v)) and reaction times (6, 12, 24, 72 h) on bioartificial nerve substitutes (BNS) consisting of nanostructured FA scaffolds. First, crosslinked BNS were studied histologically, ultrastructurally and biomechanically and then, its biocompatibility and immunomodulatory effects were ex vivo assessed with a macrophage cell line. Results showed that GP was able to improve the biomechanical resistance of BNS, which were dependent on both the GP treatment time and concentration without altering the structure. Moreover, biocompatibility analyses on macrophages confirmed high cell viability and a minimal reduction of their metabolic activity by WST-1. In addition, GP-crosslinked BNS effectively directed macrophage polarization from a pro-inflammatory (M1) towards a pro-regenerative (M2) phenotype, which was in line with the cytokines release profile. In conclusion, this study considers time and dose-dependent effects of GP in FA substitutes which exhibited increased biomechanical properties while reducing immunogenicity and promoting pro-regenerative macrophage shift. These tubular substitutes could be useful for nerve application or even other tissue engineering applications such as urethra.

Structural design and mechanical analysis of small-caliber bilayer vascular prostheses

This research comprehensively addresses the influence of structural properties and polymer type on the mechanical performance of bilayer vascular grafts. The grafts consist of inner layers with randomly distributed polycaprolactone(PCL)/polylactic acid(PLA) or poly(l-lactide-co-caprolactone)(PLCL) fibers and an outer layer with radially oriented PLCL fibers, manufactured through a sequential electrospinning process. Highlighted results indicate that tubular scaffolds possess an inner layer ranging in thickness from 62 to 94 µm, while their outer layers vary in thickness from 180 to 296 µm. In addition, radially oriented fibers enhance tensile strength in radial direction (9–11 MPa), while depending on polymer composition and wall thickness proportions of individual layers, tensile strength values change between 2.7 and 7.7 MPa in longitudinal direction. Scaffolds with elastic PCL or PLCL inner layers display higher compliance values (above 1%/mmHg × 10−2).

Hierarchical porous poly (L-lactic acid) fibrous vascular graft with controllable architectures and stable structure

Electrospun fibre has shown great potential in tissue engineering and regenerative medicine due to its high specific surface area and extracellular matrix-mimicking structure. However, fabricating an electrospun fibrous scaffold with controllable complex 3D macroscopic configuration remains a challenge. In the present study, a novel method was designed to transform 2D electrospun poly (L-lactic acid) (PLLA) fibrous membrane to tubular PLLA fibrous scaffolds with 3D complex but tailored configuration. The electrospun PLLA fibrous membrane was rolled around a designed mould and then treated with acetone. Treated vascular grafts’ length, diameter, and shape can be tailored by the mould parameters. Moreover, treated vascular grafts achieve favourable mechanical properties (Young’s modulus = 155 MPa, tensile stress = 8.79 MPa and radial force = 2.2 N) and the mechanical properties could be engineered on demand. In addition, treated vascular grafts kept their initial structure and size during long-term in vitro experiments once they were formed. In addition, with the acetone-induced recrystallization of PLLA, pristine solid PLLA fibres were changed to hierarchical porous PLLA fibres with ultra-high specific surface area (28.9 m2/g) and wettability (water contact angle = 101.32°), which has positive effects on cell adhesion and proliferation ability. A7r5 in vitro experiment shows that the proliferation rate of treated vascular grafts increased 153% at day 4 and 170.6% at day 7 compared with pristine vascular grafts.

Gas‐Separating Metal‐Organic Framework Membrane Films on Large‐Area 3D‐Printed Tubular Ceramic Scaffolds

Polycrystalline metal‐organic framework (MOF) membrane films prepared on ceramic supports can separate gases with high energy efficiency. They generally exhibit very high permeance and selectivity but suffer from cost issues through the required ceramic supports. Increasing the area and reducing the ceramic component to a minimum can be a strategy to enabling neat membranes of MOFs. In a rapid prototyping approach using 3D‐printed porous scaffolds with a double‐helical channel geometry, an increased active membrane area‐to‐volume ratio is shown. Following stereolithographic printing and debinding of a ceramic slurry, an adapted sintering protocol is employed to sinter commercially available alumina slurries into porous scaffolds. The 3D‐printed scaffolds are optimized at a porosity of 40%, with satisfying mechanical stability. Furthermore, synthetic procedures yielding omnidirectional, homogeneous coatings on the outside and inside of the tubular scaffolds are developed. Membrane films of zeolitic imidazolate framework 8 and Hong Kong University of Science and Technology 1 covering a huge 50 cm2 membrane area are produced in this way by applying a counter‐diffusion methodology. Gas‐separation performance is evaluated for H2, CO2, N2, and CH4, in single‐gas measurements and on their binary‐gas mixtures.

Silica nanoparticles enhance interfacial self-adherence of a multi-layered extracellular matrix scaffold for vascular tissue regeneration.

Based on the clinical need for grafts for vascular tissue regeneration, our group developed a customizable scaffold derived from the human amniotic membrane. Our approach consists of rolling the decellularized amniotic membrane around a mandrel to form a multilayered tubular scaffold with tunable diameter and wall thickness. Herein, we aimed to investigate if silica nanoparticles (SiNP) could enhance the adhesion of the amnion layers within these rolled grafts. To test this, we assessed the structural integrity and mechanical properties of SiNP-treated scaffolds. Mechanical tests were repeated after six months to evaluate adhesion stability in aqueous environments. Our results showed that the rolled SiNP-treated scaffolds maintained their tubular shape upon hydration, while non-treated scaffolds collapsed. By scanning electron microscopy, SiNP-treated scaffolds presented more densely packed layers than untreated controls. Mechanical analysis showed that SiNP treatment increased the scaffold's tensile strength up to tenfold in relation to non-treated controls and changed the mechanism of failure from interfacial slipping to single-point fracture. The nanoparticles reinforced the scaffolds both at the interface between two distinct layers and within each layer of the extracellular matrix. Finally, SiNP-treated scaffolds significantly increased the suture pullout force in comparison to untreated controls. Our study demonstrated that SiNP prevents the unraveling of a multilayered extracellular matrix graft while improving the scaffolds' overall mechanical properties. In addition to the generation of a robust biomaterial for vascular tissue regeneration, this novel layering technology is a promising strategy for a number of bioengineering applications.

Effective Needleless Electrospinning for the Production of Tubular Scaffolds

Effective Needleless Electrospinning for the Production of Tubular Scaffolds

Hybrid Co‐Spinning and Melt Electrowriting Approach Enables Fabrication of Heterotypic Tubular Scaffolds Resembling the Non‐Linear Mechanical Properties of Human Blood Vessels

AbstractThe current barrier to clinical translation of small‐caliber tissue‐engineered vascular grafts (TEVGs) is the long‐term patency upon implantation in vivo. Key contributors are thrombosis and stenosis caused by inadequate mechanical graft properties and mismatch of hemodynamic conditions. Herein, the authors report on an approach for the fabrication of a mechanically tunable bilayered composite TEVGs. Using a combination of solution electrospinning (SES) and melt electrowriting (MEW), it is shown that the mechanical properties can be tailored and the natural J‐shape of the stress–strain relationship can be recapitulated. Upon cell seeding, the luminal surface of the composite SES layers permits the formation of a confluent mature endothelium. MEW fibers provide structural support to promote stacking and orientation of MSCs in a near‐circumferential native vessel like direction. By adjusting the ratios of poly(ε‐caprolactone) and poly(ester‐urethane) during the SES process, TEVGs with a range of tunable mechanical properties can be manufactured. Notably, this hybrid approach permits modulation of the radial tensile properties of TEVGs to approximate different native vessels. Overall, a strategy for the fabrication of TEVGs with mechanical properties resembling those of native vessels which can help to accommodate long‐term patency of TEVGs at various treatment sites in future applications is demonstrated.

Development of tissue-engineered vascular grafts from decellularized parsley stems.

Cardiovascular diseases are mostly associated with narrowing or blockage of blood vessels, and it is the most common cause of death worldwide. The use of vascular grafts is a promising approach to bypass or replace the blocked vessels for long-term treatment. Although autologous arteries or veins are the most preferred tissue sources for vascular bypass, the limited presence and poor quality of autologous vessels necessitate seeking alternative biomaterials. Recently, synthetic grafts have gained attention as an alternative to autologous grafts. However, the high failure rate of synthetic grafts has been reported primarily due to thrombosis, atherosclerosis, intimal hyperplasia, or infection. Thrombosis, the main reason for failure upon implantation, is associated with damage or absence of endothelial cell lining in the vascular graft's luminal surface. To overcome this, tissue-engineered vascular grafts (TEVGs) have come into prominence. Alongside the well-established scaffold manufacturing techniques, decellularized plant-based constructs have recently gained significant importance and are an emerging field in tissue engineering and regenerative medicine. Accordingly, in this study, we demonstrated the fabrication of tubular scaffolds from decellularized parsley stems and recellularized them with human endothelial cells to be used as a potential TEVG. Our results suggested that the native plant DNA was successfully removed, and soft tubular biomaterials were successfully manufactured via the chemical decellularization of the parsley stems. The decellularized parsley stems showed suitable mechanical and biological properties to be used as a TEVG material, and they provided a suitable environment for the culture of human endothelial cells to attach and create a pseudo endothelium prior to implantation. This study is the first one to demonstrate the potential of the parsley stems to be used as a potential TEVG biomaterial.

Intravascular elimination of circulating tumor cells and cascaded embolization with multifunctional 3D tubular scaffolds.

The primary tumor ("root") and circulating tumor cells (CTCs; "seeds") are vital factors in tumor progression. However, current treatment strategies mainly focus on inhibiting the tumor while ignoring CTCs, resulting in tumor metastasis. Here, we design a multifunctional 3D scaffold with interconnected macropores, excellent photothermal ability and perfect bioaffinity as a blood vessel implantable device. When implanted upstream of the primary tumor, the scaffold intercepts CTCs fleeing back to the primary tumor and then forms "micro-thrombi" to block the supply of nutrients and oxygen to the tumor for embolization therapy. The scaffold implanted downstream of the tumor efficiently captures and photothermally kills the CTCs that escape from the tumor, thereby preventing metastasis. Experiments using rabbits demonstrated excellent biosafety of this scaffold with 86% of the CTC scavenging rate, 99% of the tumor inhibition rate and 100% of CTC killing efficiency. The multifunctional 3D scaffold synergistically inhibits the "root" and eliminates the "seeds" of the tumor, demonstrating its potential for localized cancer therapy with few side effects and high antitumor efficacy.

ПРОЧНЫЙ АНАЛИЗ ОПАЛУБКИ С ПРИМЕНЕНИЕМ ЛЕТНОЙ СИСТЕМЫ НА ПЛИТНО-СВАЙНОЙ КОНСТРУКЦИИ

The Semarang-Demak Toll Road was planned with detailed procedures to address disorganized road networks, increased traffic volumes, congestion, land subsidence, and tidal floods. It has toll entrances in Semarang, Genuk, and Sayung sub-districts and ends in Demak City. Its purpose is to minimize traffic jams, provide access to tourist cities, and serve as a tidal barrier sea embankment. The formwork support system's proper design is crucial to ensure the safe construction of the main structure. A unique disk lock and steel tubular scaffold are utilized for a slab-on-pile structure employing a flying falsework system. This approach results in a structurally sound and secure construction that is not susceptible to twisting, providing quick erection and disassembly, significantly improving construction efficiency. The system was employed in a portion of the Semarang-Demak toll road project, and its efficacy was evaluated using finite element analysis software. The software provides security and convenience in analyzing structures, paying attention to the nominal strength of each steel profile and the internal forces at work. All components are safe as their actual deflection falls within the maximum limit.

Unlocking the print of poly(L-lactic acid) by melt electrowriting for medical application

Melt electrowriting (MEW) is an advanced 3D printing technology to process high-resolution scaffolds. Although MEW has printed many biodegradable polymers, most of them have low printability, including poly(L-lactic acid) (PLLA) discussed in this study. While the print of PLLA scaffolds by MEW is elementarily realized, the scaffolds' limited structural change and mechanical properties influence their application. This study aims at improving the printability and the mechanical properties of the PLLA. To this end, the printability of the PLLA regarding jet lag angle and critical translation speed is investigated; the print limitation of PLLA is discovered, and the uniaxial and cyclic tensile tests for the scaffolds in linear and nonlinear structures are carried out. The results suggest that drying the PLLA before printing can significantly restrain polymer degradation to extend the printing period to approximately one day; planar PLLA scaffolds are able to reach 25 layers, 100 µm interfiber distance, and 8 × 8 cm2 in dimension, and tubular PLLA scaffolds with 6 layers are successfully printed out; the mechanical properties of the PLLA scaffold reach the level of electrospun nonwoven fabrics. Thus, this study is a milestone work for the MEW technology to extend the printable materials.