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Wang Q, Gao C, Zhai H, Peng C, Yu X, Zheng X, Zhang H, Wang X, Yu L, Wang S, Ding J. Electrospun Scaffolds are Not Necessarily Always Made of Nanofibers as Demonstrated by Polymeric Heart Valves for Tissue Engineering. Adv Healthc Mater 2024; 13:e2303395. [PMID: 38554036 DOI: 10.1002/adhm.202303395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 02/09/2024] [Indexed: 04/01/2024]
Abstract
In the last 30 years, there are ≈60 000 publications about electrospun nanofibers, but it is still unclear whether nanoscale fibers are really necessary for electrospun tissue engineering scaffolds. The present report puts forward this argument and reveals that compared with electrospun nanofibers, microfibers with diameter of ≈3 µm (named as "oligo-micro fiber") are more appropriate for tissue engineering scaffolds owing to their better cell infiltration ability caused by larger pores with available nuclear deformation. To further increase pore sizes, electrospun poly(ε-caprolactone) (PCL) scaffolds are fabricated using latticed collectors with meshes. Fiber orientation leads to sufficient mechanical strength albeit increases porosity. The latticed scaffolds exhibit good biocompatibility and improve cell infiltration. Under aortic conditions in vitro, the performances of latticed scaffolds are satisfactory in terms of the acute systolic hemodynamic functionality, except for the higher regurgitation fraction caused by the enlarged pores. This hierarchical electrospun scaffold with sparse fibers in macropores and oligo-micro fibers in filaments provides new insights into the design of tissue engineering scaffolds, and tissue engineering may provide living heart valves with regenerative capabilities for patients with severe valve disease in the future.
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Affiliation(s)
- Qunsong Wang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Caiyun Gao
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Huajuan Zhai
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Chen Peng
- Institute for Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai, 200433, China
| | - Xiaoye Yu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Xiaofan Zheng
- Institute for Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai, 200433, China
| | - Hongjie Zhang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Xin Wang
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Lin Yu
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
| | - Shengzhang Wang
- Institute for Biomechanics, Department of Aeronautics and Astronautics, Fudan University, Shanghai, 200433, China
| | - Jiandong Ding
- State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai, 200438, China
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Macromolecular Insights into the Altered Mechanical Deformation Mechanisms of Non-Polyolefin Contaminated Polyolefins. Polymers (Basel) 2022; 14:polym14020239. [PMID: 35054644 PMCID: PMC8779932 DOI: 10.3390/polym14020239] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 12/16/2021] [Accepted: 12/20/2021] [Indexed: 02/01/2023] Open
Abstract
Current recycling technologies rarely achieve 100% pure plastic fractions from a single polymer type. Often, sorted bales marked as containing a single polymer type in fact contain small amounts of other polymers as contaminants. Inevitably, this will affect the properties of the recycled plastic. This work focuses on understanding the changes in tensile deformation mechanism and the related mechanical properties of the four dominant types of polyolefin (PO) (linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP)), contaminated with three different non-polyolefin (NPO) polymers (polyamide-6 (PA-6), polyethylene terephthalate (PET), and polystyrene (PS)). Under the locally elevated stress state induced by the NPO phase, the weak interfacial adhesion typically provokes decohesion. The resulting microvoids, in turn, initiate shear yielding of the PO matrix. LLDPE, due to the linear structure and intercrystalline links, is well able to maintain high ductility when contaminated. LDPE shows deformation similar to the pure material, but with decreasing ductility as the amount of NPO increases. Addition of 20 wt% PA-6, PET, and PS causes a drop in strain at break of 79%, 63%, and 84%, respectively. The typical ductile necking of the high-crystalline HDPE and PP is strongly disturbed by the NPO phase, with a transition even to full brittle failure at high NPO concentration.
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Arrigo R, Malucelli G, Mantia FPL. Effect of the Elongational Flow on the Morphology and Properties of Polymer Systems: A Brief Review. Polymers (Basel) 2021; 13:3529. [PMID: 34685288 PMCID: PMC8541082 DOI: 10.3390/polym13203529] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/12/2021] [Accepted: 10/12/2021] [Indexed: 01/04/2023] Open
Abstract
Polymer-processing operations with dominating elongational flow have a great relevance, especially in several relevant industrial applications. Film blowing, fiber spinning and foaming are some examples in which the polymer melt is subjected to elongational flow during processing. To gain a thorough knowledge of the material-processing behavior, the evaluation of the rheological properties of the polymers experiencing this kind of flow is fundamental. This paper reviews the main achievements regarding the processing-structure-properties relationships of polymer-based materials processed through different operations with dominating elongational flow. In particular, after a brief discussion on the theoretical features associated with the elongational flow and the differences with other flow regimes, the attention is focused on the rheological properties in elongation of the most industrially relevant polymers. Finally, the evolution of the morphology of homogeneous polymers, as well as of multiphase polymer-based systems, such as blends and micro- and nano-composites, subjected to the elongational flow is discussed, highlighting the potential and the unique characteristics of the processing operations based on elongation flow, as compared to their shear-dominated counterparts.
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Affiliation(s)
- Rossella Arrigo
- Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Viale Teresa Michel 5, 15121 Alessandria, Italy; (R.A.); (G.M.)
- National Interuniversity Consortium of Materials Science and Technology, Via Giusti 9, 50121 Firenze, Italy
| | - Giulio Malucelli
- Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, Viale Teresa Michel 5, 15121 Alessandria, Italy; (R.A.); (G.M.)
- National Interuniversity Consortium of Materials Science and Technology, Via Giusti 9, 50121 Firenze, Italy
| | - Francesco Paolo La Mantia
- National Interuniversity Consortium of Materials Science and Technology, Via Giusti 9, 50121 Firenze, Italy
- Dipartimento di Ingegneria, Università di Palermo, Viale delle Scienze, 90128 Palermo, Italy
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Gopi S, Ramsay BA, Ramsay JA, Kontopoulou M. Preparation, Characterization and Processing of PCL/PHO Blends by 3D Bioplotting. INT POLYM PROC 2020. [DOI: 10.3139/217.3971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- S. Gopi
- Department of Chemical Engineering, Queen's University, Kingston, ON, Canada
| | - B. A. Ramsay
- Department of Chemical Engineering, Queen's University, Kingston, ON, Canada
| | - J. A. Ramsay
- Department of Chemical Engineering, Queen's University, Kingston, ON, Canada
| | - M. Kontopoulou
- Department of Chemical Engineering, Queen's University, Kingston, ON, Canada
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