Microtube Arrays Research Articles

The angiogenic role of the alpha 9-nicotinic acetylcholine receptor in triple-negative breast cancers.

Nicotine acts as an angiogenic factor by stimulating endogenous cholinergic pathways. Several subtypes of nicotinic acetylcholine receptors (nAChRs) have been demonstrated to be closely correlated to the formation and progression of different types of cancers. Recently, several studies have found that nicotinic acetylcholine receptors α9 (α9-nAChRs) are highly expressed in breast tumors, especially in tumors derived from patients diagnosed at advanced stages. In vitro studies have demonstrated that activation of α9-nAChRs is associated with increased proliferation and migration of breast cancer. To study the tumor-promoting role of α9-nAChRs in breast cancers, we generated a novel anti-α9-nAChR and methoxy-polyethylene glycol (mPEG) bispecific antibody (α9 BsAb) for dissecting the molecular mechanism on α9-nAChR-mediated tumor progression. Unexpectedly, we discovered the angiogenic role of α9-nAChR in nicotine-induced neovascularization of tumors. It revealed α9 BsAbs reduced nicotine-induced endothelial cell tube formation, blood vessel development in Matrigel plug assay and angiogenesis in microtube array membrane murine model (MTAMs). To unbraid the molecular mechanism of α9-nAChR in nicotine-mediated angiogenesis, the α9 BsAbs were applied and revealed the inhibitory roles in nicotine-induced production of hypoxia-inducible factor-2 alpha (HIF-2α), vascular endothelial growth factor A (VEGF-A), phosphorylated vascular endothelial growth factor receptor 2 (p-VEGFR2), vascular endothelial growth factor receptor 2 (VEGFR2) and matrix metalloproteinase-9 (MMP9) from triple-negative breast cancer cells (MDA-MB-231), suggesting α9-nAChRs played an important role in nicotine-induced angiogenesis. To confirm our results, the shRNA targeting α9-nAChRs was designed and used to silence α9-nAChR expression and then evaluated the angiogenic role of α9-nAChRs. The results showed α9 shRNA also played an inhibitory effect in blocking the nicotine-induced angiogenic signaling. Taken together, α9-nAChR played a critical role in nicotine-induced angiogenesis and this bispecific antibody (α9 BsAb) may serve as a potential therapeutic candidate for treatments of the α9 positive cancers.

Engineering 3D microenvironments with femtosecond laser-fabricated microtubes to direct neuronal network formation

The regulation of cell growth characteristics through physical structures on material surfaces plays a crucial role in advancing our understanding of cell behavior. Three-dimensional (3D) microstructures, offering multidimensional growth space and a richer nutrient environment compared to their two-dimensional counterparts, have attracted significant attention from researchers. However, the fabrication of high-precision 3D microstructures, especially those with a high aspect ratio (H-AR), remains challenging. In this study, we employ femtosecond laser to achieve exceptional precision and patterning capabilities in fabricating 3D microstructures. To enhance the manufacturing efficiency of axial 3D structures, we introduce a novel single pulse multi-photon polymerization (SP-MPP) method for efficient fabrication of H-AR micropillar and microtube structures. Our innovative approach involves a dual-aperture optical modulation method that effectively modulates the annular energy distribution, enabling the creation of H-AR microstructures. We can achieve a maximum processing height of up to 130 μm with an aspect ratio of 16 within single pulse exposure of 217 fs. Compared to the layer-by-layer scanning method, our proposed approach enhances the axial manufacturing efficiency of 3D structures by 1–2 orders of magnitude. Through experimentation, we validate the applicability of microtube structures for guiding neuronal orientation by utilizing microtube arrays in hippocampal neuronal cell culture. Our results demonstrate that neurons not only grow along the patterned microtubes but also exhibit preliminary synaptic differentiation. Furthermore, we effectively regulate the 3D patterning of neuronal growth by implementing diverse patterned microtube arrays. This proposed method enables the rapid construction of a large-scale 3D cell growth environment, offering significant advantages in inducing neuronal orientation. Consequently, this technique holds immense potential for diverse applications in biomedicine and tissue engineering, including the establishment of isolated neural networks.

Titanium-Based Metasurfaces for Optoelectronics.

We report on the fabrication method that enables the development of transparent conductive metasurfaces capable of the resonant absorption of light in specific frequency bands. The approach is based on embedding linear sp-carbon chains and metallic nanoparticles in a porous matrix of titanium dioxide (TiO2). We develop a blading technique for the formation of a periodical grating of TiO2 microtubes at the macroscale. The method allowed us to maintain the periodicity of an array of microtubes with an accuracy of ±5%. Tuning the diameter of the tubes and the concentration of metallic nanoparticles, we achieved the regime of strong resonant absorption of the fabricated complex metasurface in the visible range. Computer simulations helped revealthe regime of TE/TM-polarized laser pumping that allowed for the most efficient transformation of light energy into electric current flow. In the studied structures, the sp-carbon clusters embedded inside transparent titanium dioxide tubes play the role of atomic wires. The interplay between efficient conductivity through carbon wires and the plasmon-enhanced absorption of light allows the design of photodiode structures based on periodical metasurfaces and characterized by highly selective optical sensitivity.

Review of electrospun microtube array membrane (MTAM)-a novel new class of hollow fiber for encapsulated cell therapy (ECT) in clinical applications.

Encapsulated cell therapy (ECT) shows significant potential for treating neurodegenerative disorders including Alzheimer's and Parkinson's, which currently lack curative medicines and must be managed symptomatically. This novel technique encapsulates functional cells with a semi-permeable membrane, providing protection while enabling critical nutrients and therapeutic substances to pass through. Traditional ECT procedures, on the other hand, pose difficulties in terms of cell survival and retrieval. We introduce the Microtube Array Membrane (MTAM), a revolutionary technology that solves these constraints, in this comprehensive overview. Microtube Array Membrane has distinct microstructures that improve encapsulated cells' long-term viability by combining the advantages of macro and micron scales. Importantly, the MTAM platform improves biosafety by allowing the entire encapsulated unit to be retrieved in the event of an adverse reaction. Our findings show that MTAM-based ECT has a great potential in a variety of illness situations. For cancer treatment, hybridoma cells secreting anti-CEACAM 6 antibodies inhibit triple-negative breast cancer cell lines for an extended period of time. In animal brain models of Alzheimer's disease, hybridoma cells secreting anti-pTau antibodies successfully reduce pTau buildup, accompanied by improvements in memory performance. In mouse models, MTAM-encapsulated primary cardiac mesenchymal stem cells dramatically improve overall survival and heart function. These findings illustrate the efficacy and adaptability of MTAM-based ECT in addressing major issues such as immunological isolation, cell viability, and patient safety. We provide new possibilities for the treatment of neurodegenerative illnesses and other conditions by combining the potential of ECT with MTAM. Continued research and development in this subject has a lot of promise for developing cell therapy and giving hope to people suffering from chronic diseases.

Loading of a large Yb MOT on the 1S0 → 1P1 transition.

We present an experimental setup to laser cool and trap a large number of ytterbium atoms. Our design uses an oven with an array of micro-tubes for efficient collimation of the atomic beam, and we implement a magneto-optical trap of 174Yb on the 1S0 → 1P1 transition at 399nm. Despite the absence of a Zeeman slower, we obtain a loading of 4 × 109 at./s. We trap up to N = 109 at., where light-assisted collisions become the dominant loss mechanism. We precisely characterize our atomic beam, the loading rate of the magneto-optical trap, and several loss mechanisms relevant for trapping a large number of atoms.

Fabrication of hollow microtube arrays based on a femtosecond laser double-pulse multiphoton polymerization.

Microtubes with widely varied dimensions and materials have great prospects in functional devices applied in microoptics, microrobot, and biomedicine. However, the fabrication of vertically protruding hollow microtubes with high diameter-to-thickness ratio is challenging and few reported. Femtosecond laser two-photon polymerization can solve this problem via point-by-point scanning or SLM-based parallel processing, but the low efficiency limits its high throughput fabrication. Here, we report a novel, to the best of our knowledge, femtosecond laser double-pulse multiphoton polymerization approach for high efficiency fabrication of hollow microtube arrays. We established a two-aperture laser beam reshaping system to generate a circular beam via two rounds of Fresnel diffraction. Based on the unique laser energy distribution, hollow microtubes with high diameter-to-thickness ratio can be generated by two successively laser pulses exposure, which can improve the fabrication efficiency significantly. With the optimized parameters, we can achieve repeatable and uniform microtube array fabrication in large scale, and the yield can be 94.9%. Defocus testing showed that the proposed approach has a high range of focusing tolerance. The proposed microtube fabrication approach is meaningful in providing some enlightenment for researchers in the field of microfabrication.

Novel MCP-Windowed EUV Light Source and Its Mass Spectrometric Application for Detecting Chlorinated Methanes.

Various vacuum ultraviolet (VUV) lamps are simple and convenient VUV light sources for mass spectrometry and other research fields. However, the strong absorption of high-energy photons by window materials limits the application of an extreme ultraviolet (EUV) light. In this study, a novel high-flux EUV light source is developed using a microchannel plate (MCP) window to transmit 73.6 nm (16.9 eV) EUV light generated via the radio frequency (RF) inductive discharge of neon. The MCP used is a 0.5 mm thick glass plate with a regular array of microtubes (12 μm i.d.). The photon fluxes of the EUV light source with the MCP window (12 mm i.d.) and an aperture (1.8 mm i.d.) are ∼1.31 × 1014 and ∼9.80 × 1012 photons s-1, respectively, while their corresponding leakage flow rates of the discharge gas are 0.062 and 0.046 cm3 atom s-1, according to the contrast experiments. The transmission efficiency of the MCP to the EUV light is 30.2%, with a 1.2% deviation. An EUV photoionization time-of-flight mass spectrometer (EUV-PI-TOFMS) is built to validate the practicality of the MCP-windowed EUV light source further. The detection sensitivities in 30 s measurements for methyl chloride (CH3Cl), methylene chloride (CH2Cl2), trichloromethane (CHCl3), and carbon tetrachloride (CCl4) in synthetic air are 4366, 4120, 5854, and 4095 counts ppbv-1, respectively. The corresponding 3σ limits of detection (LODs) are 42, 34, 24, and 15 pptv. This study develops a new feasible method for efficiently utilizing high-energy EUV light, with many application prospects in scientific research.

Highly oriented microtube arrays of decagonal quasicrystal approximants in Al20Si20Mn20Fe20Ga20 high-entropy alloy

The unique structures of micro/nanotubular materials have received extensive attention, while the micro/nanotubular structures of quasicrystals or quasicrystal-related phases, especially oriented arrays, are rarely found. Here, oriented microtube arrays of high-entropy decagonal quasicrystal approximants are prepared in Al20Si20Mn20Fe20Ga20 alloy by simple melt spinning. Transmission electron microscopy revealed microtubes are mostly composed of alternating arrangements of (1/0, 2/1) quasicrystal approximant domains (lattice constants: a = 0.73 nm, b = 1.23 nm, and c = 2.24 nm) and defective (1/0, 2/1) domains. However, heat treatment leads to the change of the structure and morphology of microtubes. At 873 K, a primitive cubic phase existed, and at 973 K, microtube morphology disintegrated and the (1/0, 2/1)-related domain transformed into complex domains, showing instability. By nanoindentation testing, microtubes show the hardness of 10.9 GPa and the elastic modulus of 189.3 GPa. However, after heat treatment at 873 K, these values decreased to 5.3 GPa and 128.4 GPa, and to 3.2 GPa and 107.9 GPa at 973 K. We demonstrate that the formation of microtubes is mainly related to the temperature gradient, twinning growth of approximant domains, and also the insufficient supply of raw materials in the later stages of solidification.

Unveiling the Power of Anticancer Drug Screening: A Clinical Case Study Comparing the Effectiveness of Hollow Fiber Assay Microtube Array Membrane (MTAM-HFA) in Breast Cancer Patients.

Breast cancer is a severe public health problem, and early treatment with powerful anticancer drugs is critical for success. The researchers investigated the clinical results of a novel screening tool termed Microtube Array Membrane Hollow Fiber Assay (MTAM-HFA) in breast cancer patients in this clinical investigation. In all trial participants, the MTAM-HFA was utilized to identify active medicines for the treatment of breast cancer. The MTAM-HFA was shown to be extremely useful in predicting patient response to anticancer medication therapy in this study. Furthermore, the substantial association between the MTAM-HFA screening outcome and the clinical outcome of the respective patients emphasizes the promise of this unique screening technology in discovering effective anticancer medication combinations for the treatment of breast cancer. These findings indicate that the MTAM-HFA has clinical significance and might be a valuable tool in the development of tailored therapy for cancer care. This study provides helpful information for physicians and scientists working on breast cancer therapy research. The potential benefits of employing MTAM-HFA to find accurate therapies for breast cancer patients might lead to enhanced personalized medicine approaches to cancer care, resulting in better patient outcomes. Overall, the MTAM-HFA screening approach has the potential to revolutionize customized cancer therapy, providing hope to both patients and physicians.

Degradable Biocompatible Porous Microtube Scaffold for Extended Donor Cell Survival and Activity.

Cell therapy has significant therapeutic potential but is often limited by poor donor cell retention and viability at the host implantation site. Biomaterials can improve cell retention by providing cells with increased cell-cell and cell-matrix contacts and materials that allow three-dimensional cell culture to better recapitulate native cell morphology and function. In this study, we engineered a scaffold that allows for cell encapsulation and sustained three-dimensional cell culture. Since cell therapy is largely driven by paracrine secretions, the material was fabricated by electrospinning to have a large internal surface area, micrometer-thin walls, and nanoscale surface pores to allow for nutrient exchange without early cell permeation. The material is degradable, which allows for less invasive removal of the implant. Here, a biodegradable poly(lactic-co-glycolic acid) (PLGA) microtube array membrane was fabricated. In vitro testing showed that the material supported the culture of human dermal fibroblasts for at least 21 days, with paracrine secretion of pro-angiogenic FGF2. In vivo xenotransplantation of human cells in an immunocompetent mouse showed that donor cells could be maintained for more than one month and the material showed no obvious toxicity. Analysis of gene expression and tissue histology surrounding the implant showed that the material produced muted inflammatory and immune responses compared to a permanent implant and increased markers of angiogenesis.

Dopamine-intercalated vanadate hollow microtube arrays with S-doping for high-performance zinc-ion batteries: disorder/defect-induced clusters and a reversible phase transition.

S-undoped or -doped (C8H9NO2)0.18V2O5 (DA-VO) was synthesized by a facile one-step hydrothermal reaction of dopamine (DA) and V2O5 or VS2. Rietveld refinement reveals the intercalation of DA into V2O5 with a large interlayer spacing of 11.0 Å. The S-doped sample DA-VO (S) was obtained based on the transformation of VS2 → V2O5 and the doping of the in situ released S element. DA-VO (S) exhibits a unique morphology of hollow microtube arrays built by cross-linked nanoribbons and provides a high specific capacity (476 mA h g-1 at 0.1 A g-1) and excellent long-term cycling durability with capacity retention of ∼95.3% over 3000 cycles at 5 A g-1 and ∼77.7% over 1000 cycles at 1 A g-1. It is associated with the intercalated DA, which not only increases the interlayer spacing of vanadium oxide, but also offers extra capacity due to the phenol-keto conversion. Furthermore, the disorders/defects and polyoxovanadate clusters induced by S-doping lead to a pseudo-reversible partial phase transition of DA-VO (S) ↔ Zn-doped HxV2O5. However, the undoped counterpart only experiences a transformation of DA-VO → Zn3(OH)2V2O7·2H2O due to the irreversible capture of Zn2+, as evidenced by density functional theory (DFT) calculations.

Accelerating Neurite Growth and Directing Neuronal Connections Constrained by 3D Porous Microtubes.

Investigation of neural growth and connection is crucial in the field of neural tissue engineering. Here, using a femtosecond laser direct writing (fs-DLW) technique, we propose a directionally aligned porous microtube array as a culture system for accelerating the growth of neurons and directing the connection of neurites. These microtubes exhibited an unprecedented guidance effect toward the outgrowth of primary embryonic rat hippocampal neurons, with a wrap resembling the myelin sheaths of neurons. The speed of neurite growth inside these microtubes was significantly faster than that outside these microtubes. We also achieved selective/directing connection of neural networks inside the magnetic microtubes via precise microtube delivery to a gap between two neural clusters. This work not only proposes a powerful microtube platform for accelerated growth of neurons but also offers a new idea for constructing biological neural circuits by arranging the size, location, and pattern of microtubes.

Nb-doped VO2 single crystal microtube arrays

Nb-doped VO2 microtube arrays were fabricated by a thermal oxidation process of V–Nb alloy foils in air. The Nb-doped VO2 microtubes are featured with the rod-like, hollow, and rectangular cross-sectional single crystal, where arrays aligned nearly vertically on the surface of a Nb-doped V2O5 substrate. Phase transition examinations demonstrate that Nb doping can decrease the metal-insulator transition temperatures of VO2 by approximately 15 °C/at. % Nb, which reaches the highest decrease efficiency for metal-insulator transition temperatures of Nb-doped VO2. The phase transition route and mechanism of Nb-doped VO2 microtube arrays are revealed.

Microtube Array Membrane Encapsulated Cell Therapy: A Novel Platform Technology Solution for Treatment of Alzheimer's Disease.

Alzheimer’s disease is the most frequent form of dementia in aging population and is presently the world’s sixth largest cause of mortality. With the advancement of therapies, several solutions have been developed such as passive immunotherapy against these misfolded proteins, thereby resulting in the clearance. Within this segment, encapsulated cell therapy (ECT) solutions that utilize antibody releasing cells have been proposed with a multitude of techniques under development. Hence, in this study, we utilized our novel and patented Microtube Array Membranes (MTAMs) as an encapsulating platform system with anti-pTau antibody-secreting hybridoma cells to study the impact of it on Alzheimer’s disease. In vivo results revealed that in the water maze, the mice implanted with hybridoma cell MTAMs intracranially (IN) and subcutaneously (SC) showed improvement in the time spent the goal quadrant and escape latency. In passive avoidance, hybridoma cell loaded MTAMs (IN and SC) performed significantly well in step-through latency. At the end of treatment, animals with hybridoma cell loaded MTAMs had lower phosphorylated tau (pTau) expression than empty MTAMs had. Combining both experimental results unveiled that the clearance of phosphorylated tau might rescue the cognitive impairment associated with AD.

Abstract 200: Microtube Array Membrane-Hollow Fiber Assay (MTAM-HFA): A combination of immunocheckpoint blocker (ICBs) and secondary drug anti-cancer drug screening system with significant clinical value propositions for personalized medicine and pre-clinical drug development

Abstract Despite modern advances in technology, significant challenges still plague the development of new cancer drugs and cancer care. To address these issue, we are introducing our novel platform technology- Microtube Array Membrane-Hollow Fiber Assay (MTAM-HFA) that is based on combination of the patented MTAM membrane with unique microstructures; replacing the role of traditional hollow fibers enabled the entire HFA assay to be significantly improved in terms of clinical relevance, accuracy, reliability and cost resulting in unprecedented value propositions as an anti-cancer drug screening platform. In the current work, we have clinically demonstrated in several cases where the MTAM-HFA system is capable of accurately predicting clinical response in several Cancers-Lung, Breast and Colon cancers; with unprecedented flexibility of being screened against multiple drug class (including anti-PD1/PDL1) in monotherapy and combination therapy settings. Despite being a phenotypic based assay, the test cycle of MTAM-HFA is only 7-10 days while maintaining a very low cost of up to 60% savings when compared to traditional models such as Patient Derived Xenografts (PDX). When screening ICBs, without the need to use Genetically Engineered Mice (GEM) translates to a cost savings of 98% just for the animal model alone. The combined value proposition of MTAM-HFA makes is a suitable system fulfilling the needs of multiple stakeholders. Citation Format: Wan-Ting Huang, Chee Ho Chew, Amanda Chen, Kang-Yuan Lee, Hsing-Lun Lee, Po-Hao Feng, Jeng-Fong Chiou, Kuan-Chou Lin, Po-Li Wei, Chien-Chung Chen. Microtube Array Membrane-Hollow Fiber Assay (MTAM-HFA): A combination of immunocheckpoint blocker (ICBs) and secondary drug anti-cancer drug screening system with significant clinical value propositions for personalized medicine and pre-clinical drug development [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 200.

Microtube Array Membrane Hollow Fiber Assay (MTAM-HFA)-An Accurate and Rapid Potential Companion Diagnostic and Pharmacological Interrogation Solution for Cancer Immunotherapy (PD-1/PD-L1).

Immunotherapy is one of the most promising forms of cancer treatment. In particular, immune checkpoint blockers (ICBs) represent some of the leading candidates which many drug developers have heavily invested in. During pre-clinical development and prior to human clinical trials, animal tests are a critical component for determining the safety and efficacy of newly developed ICBs for cancer treatment. In this study, we strive to demonstrate the feasibility of using hollow fiber assay microtube array membrane (MTAM-HFA) in the screening of anti-cancer ICBs. The MTAM-HFA process was carried out by encapsulating peripheral blood mononuclear cells (PBMCs) and the target cancer cells (cell lines or primary cells) and subcutaneously implanting them into Balb/C mice. At predetermined time points combination regimens of PD-1/PD-L1+ were administered accordingly and at a predetermined time point, the MTAMs were retrieved, and cell viability assays were carried out. The outcomes of the MTAM-HFA were compared against the clinical outcome of patients. Clinical comparison demonstrated excellent correlation between the screening outcome of MTAM-HFA of PD-1/PD-L1+ combination therapy and the clinical outcome of the lung cancer patients. Basic cell studies revealed that the utilization of MTAM-HFA in PD-1/PD-L1+ combination therapy revealed enhanced T-cell activity upon the administration of the PD-1/PD-L1 drug; thereby resulting in the reduction of tumor cell viability by up to 70%, and the cytotoxic effects by 82%. The outcome was echoed in the in vivo cell studies. This suggested that the MTAM-HFA system is suitable for use in PD-1/PD-L1+ screening and the accuracy, rapidity and cost effectiveness made it extremely suitable for application as a companion diagnostic system in both personalized medicine for cancer treatment and could potentially be applied to screen for candidate compounds in the development of next generation PD-1/PD-L1+ combination therapies.

Facile fabrication of carbon microtube arrays from waste wood for use as self-supporting supercapacitor electrodes

Porous carbon materials with microtube arrays have been fabricated from larch waste wood by coupling green delignification and multistage carbonization. The pore size of the sample was effectively controlled by multistage carbonization.

A Selective Etching Route for Large-Scale Fabrication of β-Ga2O3 Micro-/Nanotube Arrays.

In this paper, based on the different etching characteristics between GaN and Ga2O3, large-scale and vertically aligned β-Ga2O3 nanotube (NT) and microtube (MT) arrays were fabricated on the GaN template by a facile and feasible selective etching method. GaN micro-/nanowire arrays were prepared first by inductively coupled plasma (ICP) etching using self-organized or patterning nickel masks as the etching masks, and then the Ga2O3 shell layer converted from GaN was formed by thermal oxidation, resulting in GaN@Ga2O3 micro-/nanowire arrays. After the GaN core of GaN@Ga2O3 micro-/nanowire arrays was removed by ICP etching, hollow Ga2O3 tubes were obtained successfully. The micro-/nanotubes have uniform morphology and controllable size, and the wall thickness can also be controlled with the thermal oxidation conditions. These vertical β-Ga2O3 micro-/nanotube arrays could be used as new materials for novel optoelectronic devices.

Tissue-Engineered Vascular Graft with Co-Culture of Smooth Muscle Cells and Human Endothelial Vein Cells on an Electrospun Poly(lactic-co-glycolic acid) Microtube Array Membrane.

Coronary artery disease is one of the major diseases that plagues today’s modern society. Conventional treatments utilize synthetic vascular grafts such as Dacron® and Teflon® in bypass graft surgery. Despite the wide adaptation, these synthetic grafts are often plagued with weaknesses such as low hemocompatibility, thrombosis, intimal hyperplasia, and risks of graft infection. More importantly, these synthetic grafts are not available at diameters of less than 6 mm. In view of these challenges, we strived to develop and adapt the electrospun Poly Lactic-co-Glycolic Acid (PLGA) Microtube Array Membrane (MTAM) vascular graft for applications smaller than 6 mm in diameter. Homogenously porous PLGA MTAMs were successfully electrospun at 5.5–8.5 kV under ambient conditions. Mechanically, the PLGA MTAMs registered a maximum tensile strength of 5.57 ± 0.85 MPa and Young’s modulus value of 1.134 ± 0.01 MPa; while MTT assay revealed that seven-day Smooth Muscle Cells (SMCs) and Human Umbilical Vein Endothelial Cells (HUVECs) registered a 6 times and 2.4 times higher cell viability when cultured in a co-culture setting in medium containing α-1 haptaglobulin. When rolled into a vascular graft, the PLGA MTAMs registered an overall degradation of 82% after 60 days of cell co-culture. After eight weeks of culturing, immunohistochemistry staining revealed the formation of a monolayer of HUVECs with tight junctions on the surface of the PLGA MTAM, and as for the SMCs housed within the lumens of the PLGA MTAMs, a monolayer with high degree of orientation was observed. The PLGA MTAM registered a burst pressure of 1092.2 ± 175.3 mmHg, which was sufficient for applications such as small diameter blood vessels. Potentially, the PLGA MTAM could be used as a suitable substrate for vascular engineering.

Ultra-High Packing Density Next Generation Microtube Array Membrane for Absorption Based Applications.

Previously, we successfully developed an extracorporeal endotoxin removal device (EERD) that is based on the novel next generation alternating microtube array membrane (MTAM-A) that was superior to the commercial equivalent. In this article, we demonstrated multiple different parameter modifications that led to multiple different types of novel new MTAM structures, which ultimately led to the formation of the MTAM-A. Contrary to the single layered MTAM, the MTAM-A series consisted of a superior packing density fiber connected in a double layered, alternating position which allowed for the greater fiber count to be packed per unit area. The respective MTAM variants were electrospun by utilizing our internally developed tri-axial electrospinning set up to produce the novel microstructures as seen in the respective MTAM variants. A key uniqueness of this study is the ability to produce self-arranged fibers into the respective MTAM variants by utilizing a single spinneret, which has not been demonstrated before. Of the MTAM variants, we observed a change in the microstructure from a single layered MTAM to the MTAM-A series when the ratio of surfactant to shell flow rate approaches 1:1.92. MTAM-A registered the greatest surface area of 2.2 times compared to the traditional single layered MTAM, with the greatest tensile strength at 1.02 ± 0.13 MPa and a maximum elongation of 57.70 ± 9.42%. The MTAM-A was selected for downstream immobilization of polymyxin B (PMB) and assembly into our own internally developed and fabricated dialyzer housing. Subsequently, the entire setup was tested with whole blood spiked with endotoxin; and benchmarked against commercial Toraymyxin fibers of the same size. The results demonstrated that the EERD based on the MTAM-A performed superior to that of the commercial equivalent, registering a rapid reduction of 73.18% of endotoxin (vs. Toraymyxin at 38.78%) at time point 15 min and a final total endotoxin removal of 89.43% (vs. Toraymyxin at 65.03%)