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Ramaraju H, Garcia-Gomez E, McAtee AM, Verga AS, Hollister SJ. Shape memory cycle conditions impact human bone marrow stromal cell binding to RGD- and YIGSR-conjugated poly (glycerol dodecanedioate). Acta Biomater 2024; 186:246-259. [PMID: 39111679 DOI: 10.1016/j.actbio.2024.07.057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 07/21/2024] [Accepted: 07/30/2024] [Indexed: 08/16/2024]
Abstract
Bioresorbable shape memory polymers (SMP) are an emerging class of polymers that can help address several challenges associated with minimally invasive surgery by providing a solution for structural tissue repair. Like most synthetic polymer networks, SMPs require additional biorelevance and modification for biomedical applications. Methodologies used to incorporate bioactive ligands must preserve SMP thermomechanics and ensure biofunctionality following in vivo delivery. We have previously described the development of a novel thermoresponsive bioresorbable SMP, poly (glycerol dodecanedioate) (PGD). In this study, cell-adhesive peptide sequences RGD and YIGSR were conjugated with PGD. We investigated 1) the impact of conjugated peptides on the fixity (Rf), recovery (Rr), and recovery rate (dRr/dT), 2) the impact of conjugated peptides on cell binding, and 3) the impact of the shape memory cycle (Tprog) on conjugated peptide functionality towards binding human bone marrow stromal cells (BMSC). Peptide conjugation conditions impact fixity but not the recovery or recovery rate (p < 0.01). Peptide-conjugated substrates increased cell attachment and proliferation compared with controls (p < 0.001). Using complementary integrin binding cell-adhesive peptides increased proliferation compared with using single peptides (p < 0.05). Peptides bound to PGD substrates exhibited specificity to their respective integrin targets. Following the shape memory cycle, peptides maintained functionality and specificity depending on the shape memory cycle conditions (p < 0.001). The dissipation of strain energy during recovery can drive differential arrangement of conjugated sequences impacting functionality, an important design consideration for functionalized SMPs. STATEMENT OF SIGNIFICANCE: Shape memory elastomers are an emerging class of polymers that are well-suited for minimally invasive repair of soft tissues. Tissue engineering approaches commonly utilize biodegradable scaffolds to deliver instructive cues, including cells and bioactive signals. Delivering these instructive cues on biodegradable shape memory elastomers requires modification with bioactive ligands. Furthermore, it is necessary to ensure the specificity of the ligands to their biological targets when conjugated to the polymer. Moreover, the bioactive ligand functionality must be conserved after completing the shape memory cycle, for applications in tissue engineering.
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Affiliation(s)
- Harsha Ramaraju
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States.
| | - Elisa Garcia-Gomez
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Annabel M McAtee
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Adam S Verga
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
| | - Scott J Hollister
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, United States
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Hu R, Yao W, Fu Y, Lu F, Chen X. Synthesis and Properties of Photocurable Polymers Derived from the Polyesters of Glycerol and Aliphatic Dicarboxylic Acids. Polymers (Basel) 2024; 16:1278. [PMID: 38732746 PMCID: PMC11085142 DOI: 10.3390/polym16091278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 04/26/2024] [Accepted: 04/30/2024] [Indexed: 05/13/2024] Open
Abstract
The rapid development of 3D printing technology and the emerging applications of shape memory elastomer have greatly stimulated the research of photocurable polymers. In this work, glycerol (Gly) was polycondensed with sebacic, dodecanedioic, or tetradecanedioic acids to provide precursor polyesters with hydroxyl or carboxyl terminal groups, which were further chemically functionalized by acryloyl chloride to introduce sufficient, photocurable, and unsaturated double bonds. The chemical structures of the acrylated polyesters were characterized by FT IR and NMR spectroscopies. The photoinitiated crosslinking behavior of the acrylated polyesters under ultraviolet irradiation without the addition of any photoinitiator was investigated. The results showed that the precursor polyesters that had a greater number of terminated hydroxyls and a less branched structure obtained a relatively high acetylation degree. A longer chain of aliphatic dicarboxylic acids (ADCAs) and higher ADCA proportion lead to a relatively lower photopolymerization rate of acrylated polyesters. However, the photocured elastomers with a higher ADCA proportion or longer-chain ADCAs resulted in better mechanical properties and a lower degradation rate. The glass transition temperature (Tg) of the elastomer increased with the alkyl chain length of the ADCAs, and a higher Gly proportion resulted in a lower Tg of the elastomer due to its higher crosslinking density. Thermal gravimetric analysis (TGA) showed that the chain length of the ADCAs and the molar ratio of Gly to ADCAs had less of an effect on the thermal stability of the elastomer. As the physicochemical properties can be adjusted by choosing the alkyl chain length of the ADCAs, as well as changing the ratio of Gly:ADCA, the photocurable polyesters are expected to be applied in multiple fields.
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Affiliation(s)
| | | | - Yingjuan Fu
- State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China; (R.H.); (W.Y.); (F.L.); (X.C.)
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Jia B, Huang H, Dong Z, Ren X, Lu Y, Wang W, Zhou S, Zhao X, Guo B. Degradable biomedical elastomers: paving the future of tissue repair and regenerative medicine. Chem Soc Rev 2024; 53:4086-4153. [PMID: 38465517 DOI: 10.1039/d3cs00923h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Degradable biomedical elastomers (DBE), characterized by controlled biodegradability, excellent biocompatibility, tailored elasticity, and favorable network design and processability, have become indispensable in tissue repair. This review critically examines the recent advances of biodegradable elastomers for tissue repair, focusing mainly on degradation mechanisms and evaluation, synthesis and crosslinking methods, microstructure design, processing techniques, and tissue repair applications. The review explores the material composition and cross-linking methods of elastomers used in tissue repair, addressing chemistry-related challenges and structural design considerations. In addition, this review focuses on the processing methods of two- and three-dimensional structures of elastomers, and systematically discusses the contribution of processing methods such as solvent casting, electrostatic spinning, and three-/four-dimensional printing of DBE. Furthermore, we describe recent advances in tissue repair using DBE, and include advances achieved in regenerating different tissues, including nerves, tendons, muscle, cardiac, and bone, highlighting their efficacy and versatility. The review concludes by discussing the current challenges in material selection, biodegradation, bioactivation, and manufacturing in tissue repair, and suggests future research directions. This concise yet comprehensive analysis aims to provide valuable insights and technical guidance for advances in DBE for tissue engineering.
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Affiliation(s)
- Ben Jia
- School of Civil Aviation, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Heyuan Huang
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Zhicheng Dong
- School of Civil Aviation, Northwestern Polytechnical University, Xi'an, 710072, China
| | - Xiaoyang Ren
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Yanyan Lu
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Wenzhi Wang
- School of Aeronautics, Northwestern Polytechnical University, Xi'an, 710072, China.
| | - Shaowen Zhou
- Department of Periodontology, College of Stomatology, Xi'an Jiaotong University, Xi'an, 710049, China
| | - Xin Zhao
- State Key Laboratory for Mechanical Behavior of Materials, and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
| | - Baolin Guo
- State Key Laboratory for Mechanical Behavior of Materials, and Frontier Institute of Science and Technology, Xi'an Jiaotong University, Xi'an, 710049, China.
- Key Laboratory of Shaanxi Province for Craniofacial Precision Medicine Research, College of Stomatology, Xi'an Jiaotong University, Xi'an 710049, China
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Liu Y, Li Y, Ji J, Fan Y, Hong J, Wang L. A Shape Memory Polymeric Shield for Protecting Corneal Endothelium During Phacoemulsification. Transl Vis Sci Technol 2024; 13:11. [PMID: 38578634 PMCID: PMC11005075 DOI: 10.1167/tvst.13.4.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 02/16/2024] [Indexed: 04/06/2024] Open
Abstract
Background The purpose of this study was to explore the protective effect of a shape memory polymeric shield on corneal endothelium during phacoemulsification in rabbits. Methods Poly-(glycerol dodecanedioate) (PGD) with a transition temperature of 24.416°C was prepared to make a shape memory shield with a thickness of 100 µm, an arc length of 14 mm, and a radius of curvature of 8.8 mm. In the control group, a phaco-tip with bevel-down was used to simulate injury to the corneal endothelium by phacoemulsification in rabbits. In the experimental group, the pre-cooled and curled shape memory shield was injected into and removed from the anterior chamber before and after phaco-power release. Anterior segment optical coherence tomography (AS-OCT), confocal microscope, trypan blue/alizarin red staining, and scanning electron microscope were performed to measure endothelial damage after surgery. Results One day postoperatively, the lost cell ratio of the control group and the experimental group were 28.08 ± 5.21% and 3.50 ± 1.43%, respectively (P < 0.0001), the damaged cell ratios were 11.83 ± 2.30% and 2.55 ± 0.52%, respectively (P < 0.0001), and the central corneal thicknesses (CCT) were 406.75 ± 16.74 µm and 340. 5 ±13.48 µm, respectively (P < 0.0001). Seven days postoperatively, the endothelial cell density (ECD) of the control group and the experimental group were 1674 ± 285/mm2 and 2561 ± 554/mm2, respectively (P < 0.05). The above differences were all statistically significant. Conclusions This PGD based shape memory shield has a protective effect on corneal endothelium during phacoemulsification. It reduces postoperative corneal edema and ECD decrease in the short term after surgery. Translational Relevance The shape memory PGD "shield" in this study may have a use in certain human patients with vulnerable corneas of low endothelial cell count or shallow anterior chambers.
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Affiliation(s)
- Yinan Liu
- Department of Ophthalmology, Peking University Third Hospital, 49th North Garden Road, Haidian District, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, 49th North Garden Road, Haidian District, Beijing, China
| | - Yuqi Li
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
| | - Jing Ji
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
| | - Jing Hong
- Department of Ophthalmology, Peking University Third Hospital, 49th North Garden Road, Haidian District, Beijing, China
- Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, 49th North Garden Road, Haidian District, Beijing, China
| | - Lizhen Wang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
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Fan Y, Hong R, Sun X, Luo Q, Wei H, Chen Y, Zhang Z, Zhou X, Wan J. Gastric acid-responsive deformable sodium alginate/Bletilla striata polysaccharide in situ gel for the protection and treatment of alcohol-induced peptic ulcers. Int J Biol Macromol 2024; 258:128815. [PMID: 38114010 DOI: 10.1016/j.ijbiomac.2023.128815] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/21/2023] [Accepted: 12/13/2023] [Indexed: 12/21/2023]
Abstract
First-line drugs for peptic ulcer (PU) treatment are typically limited by poor targeting and adverse effects associated with long-term use. Despite recent advancements in novel therapeutic approaches for PU, the development of sustained-release delivery systems tailored to specific pathological characteristics remains challenging. Persistent inflammation, particularly gastric inflammatory microenvironment imbalance, characterizes the PU. In this study, we prepared an in situ gel composed of sodium alginate, deacetylated gellan gum, calcium citrate, and Bletilla striata polysaccharide (BSP) to achieve sustained release of BSP. The BSP in situ gel demonstrated favorable fluidity in vitro and completed self-assembly in vivo in response to the acidic milieu at a pH of 1.5. Furthermore, the shear, extrusion, and deformation properties increased by 26.4 %, 103.7 %, and 46.3 %, respectively, with long-term gastric retention (4 h) and mucosal adaptation. Animal experiments confirmed that the BSP in situ gel could attenuate necrotic injury and inflammatory cell infiltration, maintain mucosal barrier integrity, regulate cytokine imbalance and inflammation-associated hyperapoptosis, thus effectively alleviate the inflammatory microenvironmental imbalance in PU without significant side effects. Overall, our findings demonstrated that the BSP in situ gel is a promising therapeutic strategy for PU and opens avenues for developing self-assembled formulations targeting the pathological features of PUs.
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Affiliation(s)
- Yilin Fan
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Ran Hong
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Xiaoli Sun
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Qiaomei Luo
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Huilin Wei
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Yajuan Chen
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Zengni Zhang
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Xia Zhou
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China
| | - Jun Wan
- School of Life Science and Engineering, Southwest Jiaotong University, 610031, China.
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Li J, Carlos C, Zhou H, Sui J, Wang Y, Silva-Pedraza Z, Yang F, Dong Y, Zhang Z, Hacker TA, Liu B, Mao Y, Wang X. Stretchable piezoelectric biocrystal thin films. Nat Commun 2023; 14:6562. [PMID: 37848410 PMCID: PMC10582159 DOI: 10.1038/s41467-023-42184-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 10/02/2023] [Indexed: 10/19/2023] Open
Abstract
Stretchability is an essential property for wearable devices to match varying strains when interfacing with soft tissues or organs. While piezoelectricity has broad application potentials as tactile sensors, artificial skins, or nanogenerators, enabling tissue-comparable stretchability is a main roadblock due to the intrinsic rigidity and hardness of the crystalline phase. Here, an amino acid-based piezoelectric biocrystal thin film that offers tissue-compatible omnidirectional stretchability with unimpaired piezoelectricity is reported. The stretchability was enabled by a truss-like microstructure that was self-assembled under controlled molecule-solvent interaction and interface tension. Through the open and close of truss meshes, this large scale biocrystal microstructure was able to endure up to 40% tensile strain along different directions while retained both structural integrity and piezoelectric performance. Built on this structure, a tissue-compatible stretchable piezoelectric nanogenerator was developed, which could conform to various tissue surfaces, and exhibited stable functions under multidimensional large strains. In this work, we presented a promising solution that integrates piezoelectricity, stretchability and biocompatibility in one material system, a critical step toward tissue-compatible biomedical devices.
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Affiliation(s)
- Jun Li
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Corey Carlos
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Hao Zhou
- Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, China
| | - Jiajie Sui
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Yikai Wang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Zulmari Silva-Pedraza
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
- Department of Surgery, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Fan Yang
- Department of Orthopaedics, Shanghai Key Laboratory for Prevention and Treatment of Bone and Joint Diseases, Shanghai Institute of Traumatology and Orthopaedics, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, Shanghai, 200025, China
| | - Yutao Dong
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Ziyi Zhang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA
| | - Timothy A Hacker
- Cardiovascular Research Center, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Bo Liu
- Department of Surgery, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, 53705, USA
| | - Yanchao Mao
- Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou, 450001, China.
| | - Xudong Wang
- Department of Materials Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
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7
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Wang L, Jin K, Li N, Xu P, Yuan H, Ramaraju H, Hollister SJ, Fan Y. Innovative design of minimal invasive biodegradable poly(glycerol-dodecanoate) nucleus pulposus scaffold with function regeneration. Nat Commun 2023; 14:3865. [PMID: 37391454 PMCID: PMC10313828 DOI: 10.1038/s41467-023-39604-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 06/21/2023] [Indexed: 07/02/2023] Open
Abstract
Minimally invasive biodegradable implants with regeneration have been a frontier trend in clinic. Degeneration of nucleus pulposus (NP) is irreversible in most of spine diseases, and traditional spinal fusion or discectomy usually injure adjacent segments. Here, an innovative minimally invasive biodegradable NP scaffold with function regeneration inspired by cucumber tendril is developed using shape memory polymer poly(glycerol-dodecanoate) (PGD), whose mechanical property is controlled to the similar with human NP by adjusting synthetic parameters. The chemokine stromal cell-derived factor-1α (SDF-1α) is immobilized to the scaffold recruiting autologous stem cells from peripheral tissue, which has better ability of maintaining disc height, recruiting autologous stem cells, and inducing regeneration of NP in vivo compared to PGD without chemokine group and hydrogel groups significantly. It provides an innovative way to design minimally invasive implants with biodegradation and functional recovery, especially for irreversible tissue injury, including NP, cartilage and so on.
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Affiliation(s)
- Lizhen Wang
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Kaixiang Jin
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Nan Li
- Department of Spine Surgery, Beijing Jishuitan Hospital, The Fourth Clinical Medical College of Peking University, Beijing, 100035, China
| | - Peng Xu
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Hao Yuan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China
| | - Harsha Ramaraju
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA
| | - Scott J Hollister
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA
| | - Yubo Fan
- Key Laboratory of Biomechanics and Mechanobiology (Beihang University), Ministry of Education, Beijing Advanced Innovation Center for Biomedical Engineering, School of Biological Science and Medical Engineering, School of Engineering Medicine, Beihang University, Beijing, 100083, China.
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Baghersad S, Sathish Kumar A, Kipper MJ, Popat K, Wang Z. Recent Advances in Tissue-Engineered Cardiac Scaffolds-The Progress and Gap in Mimicking Native Myocardium Mechanical Behaviors. J Funct Biomater 2023; 14:jfb14050269. [PMID: 37233379 DOI: 10.3390/jfb14050269] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 05/04/2023] [Accepted: 05/06/2023] [Indexed: 05/27/2023] Open
Abstract
Heart failure is the leading cause of death in the US and worldwide. Despite modern therapy, challenges remain to rescue the damaged organ that contains cells with a very low proliferation rate after birth. Developments in tissue engineering and regeneration offer new tools to investigate the pathology of cardiac diseases and develop therapeutic strategies for heart failure patients. Tissue -engineered cardiac scaffolds should be designed to provide structural, biochemical, mechanical, and/or electrical properties similar to native myocardium tissues. This review primarily focuses on the mechanical behaviors of cardiac scaffolds and their significance in cardiac research. Specifically, we summarize the recent development of synthetic (including hydrogel) scaffolds that have achieved various types of mechanical behavior-nonlinear elasticity, anisotropy, and viscoelasticity-all of which are characteristic of the myocardium and heart valves. For each type of mechanical behavior, we review the current fabrication methods to enable the biomimetic mechanical behavior, the advantages and limitations of the existing scaffolds, and how the mechanical environment affects biological responses and/or treatment outcomes for cardiac diseases. Lastly, we discuss the remaining challenges in this field and suggestions for future directions to improve our understanding of mechanical control over cardiac function and inspire better regenerative therapies for myocardial restoration.
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Affiliation(s)
- Somayeh Baghersad
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA
| | - Abinaya Sathish Kumar
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA
| | - Matt J Kipper
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA
- Department of Chemical and Biological Engineering, Colorado State University, Fort Collins, CO 80523, USA
- School of Materials Science and Engineering, Colorado State University, Fort Collins, CO 80523, USA
| | - Ketul Popat
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA
- School of Materials Science and Engineering, Colorado State University, Fort Collins, CO 80523, USA
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA
| | - Zhijie Wang
- School of Biomedical Engineering, Colorado State University, Fort Collins, CO 80523, USA
- Department of Mechanical Engineering, Colorado State University, Fort Collins, CO 80523, USA
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Li Z, Liu PX, Hou W. Modeling fibrous soft tissue dissection with elastic-plastic deformation for simulation of brain tumor removal. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2023; 232:107420. [PMID: 36854236 DOI: 10.1016/j.cmpb.2023.107420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 02/11/2023] [Accepted: 02/12/2023] [Indexed: 06/18/2023]
Abstract
BACKGROUND AND OBJECTIVE Realistic modeling the dissection of brain tissue is of key importance for simulation of brain tumor removal in virtual neurosurgery systems. However, existing methods are unable to characterize inelastic behaviors of brain tissue, such as plastic deformation and dissection evolution, making it ineffective in simulating brain tumor removal procedures. METHODS In this paper, a model of fibrous soft tissue dissection for the simulation of brain tumor removal is proposed. A dissection variable of representative volume element is used to characterize the dissection state of the fibrous soft tissue. The evolution of dissection with elastic-plastic deformation under the effects of external loads is presented. RESULTS Simulation results show that the proposed model provides realistic, stable and intuitive results in the simulation of fracture in fibrous soft tissues. As the external load increases, the fibrous soft tissue begins to crack, with the cracks growing and multiplying until they eventually merge to form a fracture. The proposed model is incorporated into the simulation of brain tumor removal. CONCLUSIONS The experimental results demonstrate the feasibility of modeling fibrous soft tissue dissection with elastic-plastic deformation. A relative high degree of realistic visual feedback is achieved.
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Affiliation(s)
- Zimeng Li
- School of Information Science and Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China
| | - Peter Xiaoping Liu
- School of Information Science and Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China; Department of Systems and Computer Engineering, Carleton University, Ottawa, ON KIS 5B6, Canada.
| | - Wenguo Hou
- School of Information Science and Engineering, Zhejiang Sci-Tech University, Hangzhou, Zhejiang, China.
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10
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Ramaraju H, McAtee AM, Akman RE, Verga AS, Bocks ML, Hollister SJ. Sterilization effects on poly(glycerol dodecanedioate): A biodegradable shape memory elastomer for biomedical applications. J Biomed Mater Res B Appl Biomater 2023; 111:958-970. [PMID: 36479954 DOI: 10.1002/jbm.b.35205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 10/31/2022] [Accepted: 11/15/2022] [Indexed: 12/13/2022]
Abstract
Biodegradable shape memory polymers provide unique regenerative medicine approaches in minimally invasive surgeries. Once heated, thermally responsive shape memory polymer devices can be compressed, programmed to fit within a small profile, delivered in the cold programmed state, and expanded when heated to body temperature. We have previously developed a biodegradable shape memory elastomer (SME), poly(glycerol dodecanedioate) (PGD), with transition temperatures near 37°C exhibiting nonlinear elastic properties like numerous soft tissues. Using SMEs in the clinic requires disinfection and sterilization methods that conserve physiochemical, thermomechanical, and shape recovery properties. We evaluated disinfection protocols using 70% ethanol and UV254 nm for research applications and ethylene oxide (EtO) gas sterilization for clinical applications. Samples disinfected with ethanol for 0.5 and 1 min showed no changes in physiochemical material properties, but after 15 min showed slower recovery rates than controls (p < .05). EtO sterilization at 54.4°C decreased transition temperatures and shape recovery rate compared to EtO sterilization at 37.8°C (p < .01) and controls (p < .05). Aging samples for 9 months in a vacuum desiccator significantly reduced shape recovery, and the recovery rate in EtO sterilized samples compared to controls (p < .001). Cytotoxicity testing (ISO-10993.5C:2012) revealed media extractions from EtO sterilized samples, sterilized at 37.8°C, and high-density polyethylene negative control samples exhibit lower cytotoxicity (IC50) than Ethanol 1 min, UV 2 h, and EtO 54.4°C. Cell viability of NIH3T3 fibroblasts on sterilized surfaces was equivalent on EtO 37.7°C, EtO 54.4°C and Ethanol sterilized substrates. Finally, chromogenic bacterial endotoxin testing showed endotoxin levels were below the FDA prescribed levels for devices contacting blood and lymphatic tissues for ethanol 1 min, UV 120 min, EtO 37.7°C, EtO 54.4°C. These findings outline various disinfection and sterilization processes for research and pre-clinical application and provide a pathway for developing custom sterilization cycles for the translation of biomedical devices utilizing PGD shape memory polymers.
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Affiliation(s)
- Harsha Ramaraju
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Annabel M McAtee
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Ryan E Akman
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Adam S Verga
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Martin L Bocks
- UH Rainbow Babies & Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, Ohio, USA
| | - Scott J Hollister
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia, USA
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Ramaraju H, Massarella D, Wong C, Verga AS, Kish EC, Bocks ML, Hollister SJ. Percutaneous delivery and degradation of a shape memory elastomer poly(glycerol dodecanedioate) in porcine pulmonary arteries. Biomaterials 2023; 293:121950. [PMID: 36580715 DOI: 10.1016/j.biomaterials.2022.121950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 11/23/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
Shape memory biodegradable elastomers are an emergent class of biomaterials well-suited for percutaneous cardiovascular repair requiring nonlinear elastic materials with facile handling. We have previously developed a chemically crosslinked shape memory elastomer, poly (glycerol dodecanedioate) (PGD), exhibiting tunable transition temperatures around body temperature (34-38 °C), exhibiting nonlinear elastic properties approximating cardiac tissues, and favorable degradation rates in vitro. Degree of tissue coverage, degradation and consequent changes in polymer thermomechanical properties, and inflammatory response in preclinical animal models are unknown material attributes required for translating this material into cardiovascular devices. This study investigates changes in the polymer structure, tissue coverage, endothelialization, and inflammation of percutaneously implanted PGD patches (20 mm × 9 mm x 0.5 mm) into the branch pulmonary arteries of Yorkshire pigs for three months. After three months in vivo, 5/8 samples exhibited (100%) tissue coverage, 2/8 samples exhibited 85-95% tissue coverage, and 1/8 samples exhibited limited (<20%) tissue coverage with mild-moderate inflammation. PGD explants showed a (60-70%) volume loss and (25-30%) mass loss, and a reduction in polymer crosslinks. Lumenal and mural surfaces and the cross-section of the explant demonstrated evidence of degradation. This study validates PGD as an appropriate cardiovascular engineering material due to its propensity for rapid tissue coverage and uneventful inflammatory response in a preclinical animal model, establishing a precedent for consideration in cardiovascular repair applications.
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Affiliation(s)
- Harsha Ramaraju
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology Atlanta, GA 30312, USA.
| | - Danielle Massarella
- UH Rainbow Babies & Children's Hospital, Department of Pediatrics, Division of Pediatric, Cardiology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Courtney Wong
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology Atlanta, GA 30312, USA
| | - Adam S Verga
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology Atlanta, GA 30312, USA
| | - Emily C Kish
- UH Rainbow Babies & Children's Hospital, Department of Pediatrics, Division of Pediatric, Cardiology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Martin L Bocks
- UH Rainbow Babies & Children's Hospital, Department of Pediatrics, Division of Pediatric, Cardiology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Scott J Hollister
- Wallace H. Coulter Department of Biomedical Engineering, Georgia Institute of Technology Atlanta, GA 30312, USA.
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Ramaraju H, Sferra SR, Kunisaki SM, Hollister SJ. Finite element analysis of esophageal atresia repair with biodegradable polymer sleeves. J Mech Behav Biomed Mater 2022; 133:105349. [DOI: 10.1016/j.jmbbm.2022.105349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/20/2022] [Accepted: 06/28/2022] [Indexed: 10/17/2022]
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Shape memory elastomers: A review of synthesis, design, advanced manufacturing, and emerging applications. POLYM ADVAN TECHNOL 2022. [DOI: 10.1002/pat.5652] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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