@article{zhang_tao_gluck_wang_daneshmand_king_2023, title={A textile-reinforced composite vascular graft that modulates macrophage polarization and enhances endothelial cell migration, adhesion and proliferation in vitro}, volume={1}, ISSN={["1744-6848"]}, url={https://doi.org/10.1039/D2SM01190E}, DOI={10.1039/D2SM01190E}, abstractNote={We engineered a textile-reinforced hydrogel vascular graft. The textile provides robustness while the hydrogel promotes endothelial cell attachment and growth. The composite enhanced macrophage activation, which increased endothelial cell migration.}, journal={SOFT MATTER}, author={Zhang, Fan and Tao, Hui and Gluck, Jessica M. and Wang, Lu and Daneshmand, Mani A. and King, Martin W.}, year={2023}, month={Jan} } @article{zhang_gluck_brown_zaharoff_king_2023, title={Heparin Affinity-Based IL-4 Delivery to Modulate Macrophage Phenotype and Endothelial Cell Activity In Vitro}, volume={15}, ISSN={1944-8244 1944-8252}, url={http://dx.doi.org/10.1021/acsami.3c00489}, DOI={10.1021/acsami.3c00489}, abstractNote={Macrophages play a pivotal role in wound healing and tissue regeneration, as they are rapidly recruited to the site of injury or implanted foreign material. Depending on their interaction with the material, macrophages can develop different phenotypes, with the M1 pro-inflammatory and M2 pro-regenerative phenotypes being highly involved in tissue regeneration. M2 macrophages mitigate inflammation and promote tissue regeneration and extracellular matrix remodeling. In this study, we engineered a gelatin-heparin-methacrylate (GelMA-HepMA) hydrogel that gradually releases interleukin-4 (IL-4), a cytokine that modulates macrophages to adopt the M2 phenotype. Methacrylation of heparin improved the retention of both heparin and IL-4 within the hydrogel. The GelMA-HepMA hydrogel and IL-4 synergistically downregulated M1 gene expression and upregulated M2 gene expression in macrophages within 48 h of in vitro cell culture. However, the M2-like macrophage phenotype induced by the GelMA-HepMA-IL-4 hydrogel did not necessarily further improve endothelial cell proliferation and migration in vitro.}, number={23}, journal={ACS Applied Materials & Interfaces}, publisher={American Chemical Society (ACS)}, author={Zhang, Fan and Gluck, Jessica M. and Brown, Ashley C. and Zaharoff, David A. and King, Martin W.}, year={2023}, month={Jun}, pages={27457–27470} } @article{xie_zhang_akkus_king_2022, title={A collagen/PLA hybrid scaffold supports tendon-derived cell growth for tendon repair and regeneration}, volume={7}, ISSN={["1552-4981"]}, url={https://doi.org/10.1002/jbm.b.35116}, DOI={10.1002/jbm.b.35116}, abstractNote={AbstractA rotator cuff tendon tear is a common shoulder injury with a relatively high rate of recurrence after surgical repair. In order to reinforce the repair and reduce the risk of clinical complications, a patch scaffold is typically sutured over the tendon tear to provide post‐surgical mechanical support. However, despite considerable research effort in this area, a patch scaffold that provides both superior initial mechanical properties and supports cell proliferation at the same time has not yet been achieved. In this study, we engineered a collagen/poly(lactic acid) (COL/PLA) hybrid yarn to leverage mechanical strength of PLA yarn and the bioactivity of collagen. The COL/PLA yarns were used to fabricate a tissue engineering scaffold using textile weaving technology. This hybrid scaffold had a tensile strength of 354.0 ± 36.0 N under dry conditions and 267.2 ± 15.9 N under wet conditions, which was satisfactory to maintain normal tendon function. By introducing COL yarns into the hybrid scaffold, the proliferation of tendon‐derived cells was significantly improved on the scaffold. Cell coverage after 28‐days of in vitro cell culture was noticeably higher on the COL yarns compared to the PLA yarns as a result of a larger number of cells and more spread cell morphology on collagen. Cells spread in multiple directions on COL yarns, which resembled a more natural cell attachment on extracellular matrix. On the contrary, the cells attached to the PLA filaments presented an elongated morphology along the fiber's axial direction. Combining the mechanical robustness of PLA and the biological activity of collagen, the woven COL/PLA hybrid scaffold has shown its potential to be a promising candidate for tendon repair applications.}, journal={JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART B-APPLIED BIOMATERIALS}, author={Xie, Yu and Zhang, Fan and Akkus, Ozan and King, Martin W.}, year={2022}, month={Jul} } @article{zhang_scull_gluck_brown_king_2022, title={Effects of sterilization methods on gelatin methacryloyl hydrogel properties and macrophage gene expression in vitro}, volume={18}, ISSN={1748-6041 1748-605X}, url={http://dx.doi.org/10.1088/1748-605X/aca4b2}, DOI={10.1088/1748-605X/aca4b2}, abstractNote={Abstract To assure the long-term safety and functional performance after implantation, it is of critical importance to completely sterilize a biomaterial implant. Ineffective sterilization can cause severe inflammation and infection at the implant site, leading to detrimental events of morbidity and even mortality. Macrophages are pivotal players in the inflammatory and foreign body response after implanting a biomaterial in the body. However, the relationship between the sterilization procedure and macrophage response has not been established. In this study, three commonly used sterilization methods, including autoclaving, ethylene oxide gas and ethanol treatment, were used to sterilize a gelatin methacryloyl hydrogel. The impacts of different sterilization methods on the structure and physical properties of the hydrogel were compared. Macrophage responses to the sterilized hydrogel were analyzed based on their morphology, viability and in vitro gene expression. It was found that the sterilization methods only marginally altered the hydrogel morphology, swelling behavior and elastic modulus, but significantly impacted macrophage gene expression within 48 h and over 7 d in vitro. Therefore, when selecting sterilization methods for GelMA hydrogel, not only the sterility and hydrogel properties, such as material destruction and degradation caused by temperature and moisture, should be taken into consideration, but also the cellular responses to the sterilized material which could be substantially different.}, number={1}, journal={Biomedical Materials}, publisher={IOP Publishing}, author={Zhang, Fan and Scull, Grant and Gluck, Jessica M and Brown, Ashley C and King, Martin W}, year={2022}, month={Dec}, pages={015015} } @article{zhang_king_2022, title={Immunomodulation Strategies for the Successful Regeneration of a Tissue-Engineered Vascular Graft}, volume={3}, ISSN={["2192-2659"]}, url={https://doi.org/10.1002/adhm.202200045}, DOI={10.1002/adhm.202200045}, abstractNote={AbstractCardiovascular disease leads to the highest morbidity worldwide. There is an urgent need to solve the lack of a viable arterial graft for patients requiring coronary artery bypass surgery. The current gold standard is to use the patient's own blood vessel, such as a saphenous vein graft. However, some patients do not have appropriate vessels to use because of systemic disease or secondary surgery. On the other hand, there is no commercially available synthetic vascular graft available on the market for small diameter (<6 mm) blood vessels like coronary, carotid, and peripheral popliteal arteries. Tissue‐engineered vascular grafts (TEVGs) are studied in recent decades as a promising alternative to synthetic arterial prostheses. Yet only a few studies have proceeded to a clinical trial. Recent studies have uncovered that the host immune response can be directed toward increasing the success of a TEVG by shedding light on ways to modulate the macrophage response and improve the tissue regeneration outcome. In this review, the basic concepts of vascular tissue engineering and immunoengineering are considered. The state‐of‐art of TEVGs is summarized and the role of macrophages in TEVG regeneration is analyzed. Current immunomodulatory strategies based on biomaterials are also discussed.}, journal={ADVANCED HEALTHCARE MATERIALS}, author={Zhang, Fan and King, Martin W.}, year={2022}, month={Mar} } @article{zhang_bambharoliya_xie_liu_celik_wang_akkus_king_2021, title={A hybrid vascular graft harnessing the superior mechanical properties of synthetic fibers and the biological performance of collagen filaments}, volume={118}, ISSN={["1873-0191"]}, url={http://dx.doi.org/10.1016/j.msec.2020.111418}, DOI={10.1016/j.msec.2020.111418}, abstractNote={Tissue-engineered small caliber vascular grafts have attracted much research attention as a viable alternative to traditional vascular grafts with their biocompatibility and potential to achieve complete healing. However, the major challenge is to fabricate a scaffold with both satisfactory mechanical properties and fast endothelialization. In this study, a hybrid tubular vascular tissue engineered scaffold has been circular-knitted using novel electrochemically aligned collagen (ELAC) filaments plied together with traditional poly(lactic acid) (PLA) yarn. The collagen component was able to promote the recruitment and proliferation of endothelial cells by increasing the initial cell adhesion 10-fold and the eventual cell population 3.2 times higher than the PLA scaffold alone. At the same time, the PLA yarn was able to provide sufficient mechanical strength and structural stability, as well as facilitate scaffold fabrication on high speed textile production equipment. The tubular hybrid scaffold exhibited excellent bursting strength (1.89 ± 0.43 MPa) and suture retention strength (10.86 ± 0.49 N), and had comparable compliance (3.98 ± 1.94%/100 mmHg) to that of the coronary artery (3.8 ± 0.3%/100 mmHg) under normotensive pressure. With its excellent mechanical and biological performance, this prototype hybrid scaffold is a promising candidate for the construction of a clinically successful and easily translatable tissue-engineered small caliber vascular graft.}, journal={MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS}, publisher={Elsevier BV}, author={Zhang, Fan and Bambharoliya, Tushar and Xie, Yu and Liu, Laijun and Celik, Hakan and Wang, Lu and Akkus, Ozan and King, Martin W.}, year={2021}, month={Jan} } @article{zhang_king_2020, title={Biodegradable Polymers as the Pivotal Player in the Design of Tissue Engineering Scaffolds}, volume={5}, url={https://doi.org/10.1002/adhm.201901358}, DOI={10.1002/adhm.201901358}, abstractNote={AbstractBiodegradable polymers play a pivotal role in in situ tissue engineering. Utilizing various technologies, researchers have been able to fabricate 3D tissue engineering scaffolds using biodegradable polymers. They serve as temporary templates, providing physical and biochemical signals to the cells and determining the successful outcome of tissue remodeling. Furthermore, a biodegradable scaffold also presents the fourth dimension for tissue engineering, namely time. The properties of the biodegradable polymer change over time, presenting continuously changing features during the degradation process. These changes become more complicated when different materials are combined together to fabricate a composite or heterogeneous scaffold. This review undertakes a systematic analysis of the basic characteristics of biodegradable polymers and describe recent advances in making composite biodegradable scaffolds for in situ tissue engineering and regenerative medicine. The interaction between implanted biodegradable biomaterials and the in vivo environment are also discussed, including the properties and functional changes of the degradable scaffold, the local effect of degradation on the contiguous tissue and their evaluation using both in vitro and in vivo models.}, journal={Advanced Healthcare Materials}, publisher={Wiley}, author={Zhang, Fan and King, Martin W.}, year={2020}, month={Jul}, pages={1901358} } @book{coronary artery disease and the evolution of angioplasty devices_2020, url={http://dx.doi.org/10.1007/978-3-030-42443-5}, DOI={10.1007/978-3-030-42443-5}, journal={SpringerBriefs in Materials}, year={2020}, month={May} } @article{zahabi_white_zhang_winslow_zhang_huang_kaber_2019, title={Application of Cognitive Task Performance Modeling for Assessing Usability of Transradial Prostheses}, volume={49}, ISSN={["2168-2305"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-85063397939&partnerID=MN8TOARS}, DOI={10.1109/THMS.2019.2903188}, abstractNote={The goal of this study was to investigate the use of cognitive modeling to assess the usability of an upper-limb prosthesis with a focus on mental workload responses. Prior studies have investigated usability of upper-limb prostheses with subjective surveys and physiological measures. However, these approaches have limitations, including subject recall of conditions and physiological response contamination by head and body movements and user speech during task performance as well as sensitivity to physical fatigue and room lighting conditions. Cognitive modeling was used to assess mental workload in use of transradial upper-limb prosthesis. A case study was conducted with a participant with upper-limb amputation using two different types of electromyography-based control schemes, including conventional direct control (DC) and pattern recognition (PR) control in order to compare cognitive model outcomes with mental workload assessment using eye-tracking measures. Cognitive models time estimates were also compared with actual task completion time results from the case study to further assess the validity of cognitive modeling as an analytical tool for evaluating upper limb prosthesis usability. Findings of both the cognitive models and case study revealed the PR mode to be more intuitive, reduce cognitive load, and increase efficiency in prosthetic control as compared to the DC mode. Results of the present study revealed that cognitive modeling can be used as an analytical approach for assessing upper-limb prosthetic device usability in terms of workload outcomes. Future studies should validate the present findings with more precise time estimations and a larger user sample size.}, number={4}, journal={IEEE TRANSACTIONS ON HUMAN-MACHINE SYSTEMS}, author={Zahabi, Maryam and White, Melissa Mae and Zhang, Wenjuan and Winslow, Anna T. and Zhang, Fan and Huang, He and Kaber, David B.}, year={2019}, month={Aug}, pages={381–387} } @article{zhang_xie_celik_akkus_bernacki_king_2019, title={Engineering small-caliber vascular grafts from collagen filaments and nanofibers with comparable mechanical properties to native vessels}, volume={11}, ISSN={["1758-5090"]}, url={https://doi.org/10.1088/1758-5090/ab15ce}, DOI={10.1088/1758-5090/ab15ce}, abstractNote={At the present time, there is no successful synthetic, off-the-shelf small-caliber vascular graft (<6 mm) for the repair or bypass of the coronary or carotid arteries. This stimulates on-going investigations to fabricate an artificial vascular graft that has both sufficient mechanical properties as well as superior biological performance. Collagen has long been considered as a viable material to encourage cell recruitment, tissue regeneration, and revascularization, but its use has been limited by its inferior mechanical properties. In this study, novel electrochemically aligned collagen filaments were used to engineer a bilayer small-caliber vascular graft, by circular knitting the collagen filaments and electrospinning collagen nanofibers. The collagen prototype grafts showed significantly greater bursting strength under dry and hydrated conditions to that of autografts such as the human internal mammary artery and the saphenous vein (SV). The suture retention strength was sufficient under dry condition, but that under hydrated condition needs to be further improved. The radial dynamic compliance of the collagen grafts was similar to that of the human SV. During in vitro cell culture assays with human umbilical vein endothelial cells, the prototype collagen grafts also encouraged cell adhesion and promoted cell proliferation compared to the synthetic poly(lactic acid) grafts. In conclusion, this study demonstrated the feasibility of the use of novel collagen filaments for fabricating small caliber tissue-engineered vascular grafts that provide both sufficient mechanical properties and superior biological performance.}, number={3}, journal={BIOFABRICATION}, publisher={IOP Publishing}, author={Zhang, Fan and Xie, Yu and Celik, Hakan and Akkus, Ozan and Bernacki, Susan H. and King, Martin W.}, year={2019}, month={Jul} } @inbook{king_chen_deshpande_he_ramakrishna_xie_zhang_zhao_2019, title={Structural Design, Fabrication and Evaluation of Resorbable Fiber-Based Tissue Engineering Scaffolds}, url={http://dx.doi.org/10.5772/intechopen.84643}, DOI={10.5772/intechopen.84643}, abstractNote={The use of tissue engineering to regenerate viable tissue relies on selecting the appropriate cell line, developing a resorbable scaffold and optimizing the culture conditions including the use of biomolecular cues and sometimes mechanical stimulation. This review of the literature focuses on the required scaffold properties, including the polymer material, the structural design, the total porosity, pore size distribution, mechanical performance, physical integrity in multiphase structures as well as surface morphology, rate of resorption and biocompatibility. The chapter will explain the unique advantages of using textile technologies for tissue engineering scaffold fabrication, and will delineate the differences in design, fabrication and performance of woven, warp and weft knitted, braided, nonwoven and electrospun scaffolds. In addition, it will explain how different types of tissues can be regener-ated by each textile technology for a particular clinical application. The use of different synthetic and natural resorbable polymer fibers will be discussed, as well as the need for specialized finishing techniques such as heat setting, cross linking, coating and impregnation, depending on the tissue engineering application.}, booktitle={Biotechnology and Bioengineering}, author={King, M.W. and Chen, J. and Deshpande, M. and He, T. and Ramakrishna, H. and Xie, Y. and Zhang, F. and Zhao, F.}, editor={In E. Jacob-Lopes, & L. Queiroz Zepka (Eds.Editor}, year={2019}, month={Nov} }