SHAPE MEMORY MICROANCHORS WITH MAGNETIC GUIDANCE FOR INTRAVASCULAR MICROEMBOLIZATION

Untethered intelligent microdevices through the circulatory system show great potential for therapy but lack strategies to stably anchor them at the desired site in vascularized tissues to take action. This thesis presents a new strategy to develop an untethered shape memory polymeric microsystem capable of performing radial expansion to precisely lock inside the confined space of microscale vasculatures for biomedical applications.  We refer to this system as a shape memory magnetic microanchor (i.e., SM²A), which requires (1) biocompatibility in selected materials; (2) proper positioning with remote control; and (3) precisely controlled radial expansion with a proper recovery speed at a body-friendly shape recovery temperature. We developed SM²A with tunable shape recovery modes that could be thermally activated within a hyperthermia temperature range (37-45 °C) at a rapid speed to achieve precise microembolization in the vasculature. We designed a facile film sequential stretching processing technique that manipulates the polymer orientation of the shape memory microsystem at distinctive temperature settings to memorize versatile particle shapes. This approach produces purely entropy-driven shape recovery behavior precisely controlled by the polymeric glass transition, and features precisely controlled shape transformations to facilitate endovascular radial expansion. The SM²A system incorporated with superparamagnetic Fe₃O₄ nanoparticles can be remotely guided by a magnetic field through microscale vascular branches and subsequently undergo on-site radial expansion to anchor at a predetermined location upon shape recovery.  Such a microdevice has the potential to be employed for transcatheter embolization therapies and other biomedical applications that need precise delivery of therapeutic agents to vascularized tissues.

[1] J. Li, B. Esteban-Fernandez de Avila, W. Gao, L. Zhang, J. Wang, Micro/nanorobots for biomedicine: Delivery, surgery, sensing, and detoxification, Sci. Robot. 2(4) (2017) eaam6431. https://doi.org/10.1126/scirobotics.aam6431.
[2] S.K. Srivastava, G. Clergeaud, T.L. Andresen, A. Boisen, Micromotors for drug delivery in vivo: The road ahead, Adv. Drug Deliv. Rev. 138 (2019) 41-55. https://doi.org/10.1016/j.addr.2018.09.005.
[3] C. Gao, Y. Wang, Z. Ye, Z. Lin, X. Ma, Q. He, Biomedical micro-/nanomotors: From overcoming biological barriers to in vivo imaging, Adv Mater 33(6) (2021) e2000512. https://doi.org/10.1002/adma.202000512.
[4] G. Go, A. Yoo, H.W. Song, H.K. Min, S. Zheng, K.T. Nguyen, S. Kim, B. Kang, A. Hong, C.S. Kim, J.O. Park, E. Choi, Multifunctional biodegradable microrobot with programmable morphology for biomedical applications, ACS Nano 15(1) (2021) 1059-1076. https://doi.org/10.1021/acsnano.0c07954.
[5] M. Thiriet, K.H. Parker, Physiology and pathology of the cardiovascular system: A physical perspective, in: L. Formaggia, A. Quarteroni, A. Veneziani (Eds.), Cardiovascular mathematics: Modeling and simulation of the circulatory system, Springer Milan, Milano, 2009, pp. 1-45.
[6] R. Lopez-Benitez, G.M. Richter, H.U. Kauczor, S. Stampfl, J. Kladeck, B.A. Radeleff, M. Neukamm, P.J. Hallscheidt, Analysis of nontarget embolization mechanisms during embolization and chemoembolization procedures, Cardiovasc. Intervent. Radiol. 32(4) (2009) 615-622. https://doi.org/10.1007/s00270-009-9568-9.
[7] A.W. Heldman, L. Cheng, G.M. Jenkins, P.F. Heller, D.W. Kim, M. Ware, C. Nater, R.H. Hruban, B. Rezai, B.S. Abella, K.E. Bunge, J.L. Kinsella, S.J. Sollott, E.G. Lakatta, J.A. Brinker, W.L. Hunter, J.P. Froehlich, Paclitaxel stent coating inhibits neointimal hyperplasia at 4 weeks in a porcine model of coronary restenosis, Circulation 103(18) (2001) 2289-2295. https://doi.org/10.1161/01.CIR.103.18.2289.
[8] S. Chen, B. Zhang, B. Zhang, H. Lin, H. Yang, F. Zheng, M. Chen, Y. Ke, Assessment of structure integrity, corrosion behavior and microstructure change of az31b stent in porcine coronary arteries, J. Mater. Sci. Technol. 39 (2020) 39-47. https://doi.org/10.1016/j.jmst.2018.12.017.
[9] H. Kitahara, K. Okada, T. Kimura, P.G. Yock, A.J. Lansky, J.J. Popma, A.C. Yeung, P.J. Fitzgerald, Y. Honda, Impact of stent size selection on acute and long-term outcomes after drug-eluting stent implantation in de novo coronary lesions, Circ. Cardiovasc. Interv. 10(10) (2017) e004795. https://doi.org/10.1161/CIRCINTERVENTIONS.116.004795.
[10] L. Sun, X. Gao, D. Wu, Q. Guo, Advances in physiologically relevant actuation of shape memory polymers for biomedical applications, Polym. Rev. (2020) 1-39. https://doi.org/10.1080/15583724.2020.1825487.
[11] J.N. Rodriguez, F.J. Clubb, T.S. Wilson, M.W. Miller, T.W. Fossum, J. Hartman, E. Tuzun, P. Singhal, D.J. Maitland, In vivo response to an implanted shape memory polyurethane foam in a porcine aneurysm model, J. Biomed. Mater. Res. A 102(5) (2014) 1231-1242. https://doi.org/10.1002/jbm.a.34782.
[12] Y. Zhang, H. Gao, H. Wang, Z. Xu, X. Chen, B. Liu, Y. Shi, Y. Lu, L. Wen, Y. Li, Z. Li, Y. Men, X. Feng, W. Liu, Radiopaque highly stiff and tough shape memory hydrogel microcoils for permanent embolization of arteries, Adv. Funct. Mater. 28(9) (2018) 1705962. https://doi.org/10.1002/adfm.201705962.
[13] S. Sharifi, T.G. van Kooten, H.J. Kranenburg, B.P. Meij, M. Behl, A. Lendlein, D.W. Grijpma, An annulus fibrosus closure device based on a biodegradable shape-memory polymer network, Biomaterials 34(33) (2013) 8105-8113. https://doi.org/10.1016/j.biomaterials.2013.07.061.
[14] X. Jing, H.Y. Mi, H.X. Huang, L.S. Turng, Shape memory thermoplastic polyurethane (tpu)/poly(epsilon-caprolactone) (pcl) blends as self-knotting sutures, J. Mech. Behav. Biomed. Mater. 64 (2016) 94-103. https://doi.org/10.1016/j.jmbbm.2016.07.023.
[15] Y. Zheng, Y. Li, X. Hu, J. Shen, S. Guo, Biocompatible shape memory blend for self-expandable stents with potential biomedical applications, ACS Appl. Mater. Interfaces 9(16) (2017) 13988-13998. https://doi.org/10.1021/acsami.7b04808.
[16] X. Wan, H.Q. Wei, F.H. Zhang, Y.J. Liu, J.S. Leng, 3d printing of shape memory poly(d,l-lactide-co-trimethylene carbonate) by direct ink writing for shape-changing structures, J Appl Polym Sci 136(44) (2019) 48177. https://doi.org/10.1002/app.48177.
[17] Q. Ge, Z. Chen, J. Cheng, B. Zhang, Y.F. Zhang, H. Li, X. He, C. Yuan, J. Liu, S. Magdassi, S. Qu, 3d printing of highly stretchable hydrogel with diverse uv curable polymers, Sci. Adv. 7(2) (2021) eaba4261. https://doi.org/10.1126/sciadv.aba4261.
[18] R. Zamani Alavijeh, P. Shokrollahi, J. Barzin, A thermally and water activated shape memory gelatin physical hydrogel, with a gel point above the physiological temperature, for biomedical applications, J. Mater. Chem. B 5(12) (2017) 2302-2314. https://doi.org/10.1039/c7tb00014f.
[19] M. Jahangiri, A.E. Kalajahi, M. Rezaei, M. Bagheri, Shape memory hydroxypropyl cellulose-g-poly (ε-caprolactone) networks with controlled drug release capabilities, J. Polym. Res. 26(6) (2019) 136. https://doi.org/10.1007/s10965-019-1798-1.
[20] S.M. Brosnan, A.M. Jackson, Y. Wang, V.S. Ashby, Shape memory particles capable of controlled geometric and chemical asymmetry made from aliphatic polyesters, Macromol. Rapid Commun. 35(19) (2014) 1653-1660. https://doi.org/10.1002/marc.201400199.
[21] L.M. Cox, J.P. Killgore, Z. Li, Z. Zhang, D.C. Hurley, J. Xiao, Y. Ding, Morphing metal-polymer janus particles, Adv. Mater. 26(6) (2014) 899-904. https://doi.org/10.1002/adma.201304079.
[22] F. Friess, U. Nochel, A. Lendlein, C. Wischke, Polymer micronetworks with shape-memory as future platform to explore shape-dependent biological effects, Adv. Healthcare Mater. 3(12) (2014) 1986-1990. https://doi.org/10.1002/adhm.201400433.
[23] T. Gong, K. Zhao, W. Wang, H. Chen, L. Wang, S. Zhou, Thermally activated reversible shape switch of polymer particles, J. Mater. Chem. B 2(39) (2014) 6855-6866. https://doi.org/10.1039/c4tb01155d.
[24] C. Wischke, A. Lendlein, Method for preparation, programming, and characterization of miniaturized particulate shape-memory polymer matrices, Langmuir 30(10) (2014) 2820-2827. https://doi.org/10.1021/la4025926.
[25] C. Wischke, M. Schossig, A. Lendlein, Shape-memory effect of micro-/nanoparticles from thermoplastic multiblock copolymers, Small 10(1) (2014) 83-87. https://doi.org/10.1002/smll.201202213.
[26] Q. Zhang, T. Sauter, L. Fang, K. Kratz, A. Lendlein, Shape-memory capability of copolyetheresterurethane microparticles prepared via electrospraying, Macromol. Mater. Eng. 300(5) (2015) 522-530. https://doi.org/10.1002/mame.201400267.
[27] L.M. Cox, J.P. Killgore, Z. Li, R. Long, A.W. Sanders, J. Xiao, Y. Ding, Influences of substrate adhesion and particle size on the shape memory effect of polystyrene particles, Langmuir 32(15) (2016) 3691-3698. https://doi.org/10.1021/acs.langmuir.6b00588.
[28] Q. Guo, C.J. Bishop, R.A. Meyer, D.R. Wilson, L. Olasov, D.E. Schlesinger, P.T. Mather, J.B. Spicer, J.H. Elisseeff, J.J. Green, Entanglement-based thermoplastic shape memory polymeric particles with photothermal actuation for biomedical applications, ACS Appl. Mater. Interfaces 10(16) (2018) 13333-13341. https://doi.org/10.1021/acsami.8b01582.
[29] C. Zhou, Y. Ni, W. Liu, B. Tan, M. Yao, L. Fang, C. Lu, Z. Xu, Near-infrared light-induced sequential shape recovery and separation of assembled temperature memory polymer microparticles, Macromol. Rapid Commun. 41(8) (2020) e2000043. https://doi.org/10.1002/marc.202000043.
[30] Y. Liu, M.Y. Razzaq, T. Rudolph, L. Fang, K. Kratz, A. Lendlein, Two-level shape changes of polymeric microcuboids prepared from crystallizable copolymer networks, Macromolecules 50(6) (2017) 2518-2527. https://doi.org/10.1021/acs.macromol.6b02237.
[31] Y. Liu, O.E.C. Gould, T. Rudolph, L. Fang, K. Kratz, A. Lendlein, Polymeric microcuboids programmable for temperature‐memory, Macromol. Mater. Eng. 305(10) (2020) 2000333. https://doi.org/10.1002/mame.202000333.
[32] F. Zhang, T. Zhao, D. Ruiz-Molina, Y. Liu, C. Roscini, J. Leng, S.K. Smoukov, Shape memory polyurethane microcapsules with active deformation, ACS Appl. Mater. Interfaces 12(41) (2020) 47059-47064. https://doi.org/10.1021/acsami.0c14882.
[33] J. Zhang, X. Zheng, F. Wu, B. Yan, S. Zhou, S. Qu, J. Weng, Shape memory actuation of janus nanoparticles with amphipathic cross-linked network, ACS Macro Lett. 5(12) (2016) 1317-1321. https://doi.org/10.1021/acsmacrolett.6b00730.
[34] B. Yan, X. Zheng, P. Tang, H. Yang, J. He, S. Zhou, Investigating switchable nanostructures in shape memory process for amphipathic janus nanoparticles, ACS Appl. Mater. Interfaces 10(42) (2018) 36249-36258. https://doi.org/10.1021/acsami.8b11276.
[35] Y. Zhang, H. Gao, H. Wang, Z. Xu, X. Chen, B. Liu, Y. Shi, Y. Lu, L. Wen, Y. Li, Z. Li, Y. Men, X. Feng, W. Liu, Radiopaque highly stiff and tough shape memory hydrogel microcoils for permanent embolization of arteries, Advanced Functional Materials 28(9) (2018). https://doi.org/10.1002/adfm.201705962.
[36] B. Liu, Z. Xu, H. Gao, C. Fan, G. Ma, D. Zhang, M. Xiao, B. Zhang, Y. Yang, C. Cui, T. Wu, X. Feng, W. Liu, Stiffness self‐tuned shape memory hydrogels for embolization of aneurysms, Advanced Functional Materials 30(22) (2020). https://doi.org/10.1002/adfm.201910197.
[37] D. Shi, H. Zhang, H. Zhang, L. Li, S. Li, Y. Zhao, C. Zheng, G. Nie, X. Yang, The synergistic blood-vessel-embolization of coagulation fusion protein with temperature sensitive nanogels in interventional therapies on hepatocellular carcinoma, Chemical Engineering Journal 433 (2022). https://doi.org/10.1016/j.cej.2021.134357.
[38] H. Li, K. Qian, H. Zhang, L. Li, L. Yan, S. Geng, H. Zhao, H. Zhang, B. Xiong, Z. Li, C. Zheng, Y. Zhao, X. Yang, Pickering gel emulsion of lipiodol stabilized by hairy nanogels for intra-artery embolization antitumor therapy, Chemical Engineering Journal 418 (2021). https://doi.org/10.1016/j.cej.2021.129534.
[39] L. Li, Y. Liu, H. Li, X. Guo, X. He, S. Geng, H. Zhao, X. Peng, D. Shi, B. Xiong, G. Zhou, Y. Zhao, C. Zheng, X. Yang, Rational design of temperature-sensitive blood-vessel-embolic nanogels for improving hypoxic tumor microenvironment after transcatheter arterial embolization, Theranostics 8(22) (2018) 6291-6306. https://doi.org/10.7150/thno.28845.
[40] Y. Liu, X. Peng, K. Qian, Y. Ma, J. Wan, H. Li, H. Zhang, G. Zhou, B. Xiong, Y. Zhao, C. Zheng, X. Yang, Temperature sensitive p(n-isopropylacrylamide-co-acrylic acid) modified gold nanoparticles for trans-arterial embolization and angiography, J Mater Chem B 5(5) (2017) 907-916. https://doi.org/10.1039/c6tb02383e.
[41] Y. Ma, J. Wan, K. Qian, S. Geng, N. He, G. Zhou, Y. Zhao, X. Yang, The studies on highly concentrated complex dispersions of gold nanoparticles and temperature-sensitive nanogels and their application as new blood-vessel-embolic materials with high-resolution angiography, J Mater Chem B 2(36) (2014) 6044-6053. https://doi.org/10.1039/c4tb00748d.
[42] Y. Zhao, C. Zheng, Q. Wang, J. Fang, G. Zhou, H. Zhao, Y. Yang, H. Xu, G. Feng, X. Yang, Permanent and peripheral embolization: Temperature-sensitive p(n-isopropylacrylamide-co-butyl methylacrylate) nanogel as a novel blood-vessel-embolic material in the interventional therapy of liver tumors, Advanced Functional Materials 21(11) (2011) 2035-2042. https://doi.org/10.1002/adfm.201002510.
[43] T. Mu, L. Liu, X. Lan, Y. Liu, J. Leng, Shape memory polymers for composites, Composites Science and Technology 160 (2018) 169-198. https://doi.org/10.1016/j.compscitech.2018.03.018.
[44] H. Yang, X. Zheng, Z. Zheng, J. He, D. Kong, K. Ding, S. Zhou, Precise control of shape-variable nanomicelles in nanofibers reveals the enhancement mechanism of passive delivery, ACS Appl Mater Interfaces 13(46) (2021) 54715-54726. https://doi.org/10.1021/acsami.1c15858.
[45] Q. Guo, C.J. Bishop, R.A. Meyer, D.R. Wilson, L. Olasov, D.E. Schlesinger, P.T. Mather, J.B. Spicer, J.H. Elisseeff, J.J. Green, Entanglement-based thermoplastic shape memory polymeric particles with photothermal actuation for biomedical applications, ACS Appl Mater Interfaces 10(16) (2018) 13333-13341. https://doi.org/10.1021/acsami.8b01582.
[46] T. Gong, K. Zhao, W. Wang, H. Chen, L. Wang, S. Zhou, Thermally activated reversible shape switch of polymer particles, J Mater Chem B 2(39) (2014) 6855-6866. https://doi.org/10.1039/c4tb01155d.
[47] F. Friess, U. Nochel, A. Lendlein, C. Wischke, Polymer micronetworks with shape-memory as future platform to explore shape-dependent biological effects, Adv Healthc Mater 3(12) (2014) 1986-1990. https://doi.org/10.1002/adhm.201400433.
[48] S.M. Brosnan, A.M. Jackson, Y. Wang, V.S. Ashby, Shape memory particles capable of controlled geometric and chemical asymmetry made from aliphatic polyesters, Macromol Rapid Commun 35(19) (2014) 1653-1660. https://doi.org/10.1002/marc.201400199.
[49] C. Zhou, Y. Ni, W. Liu, B. Tan, M. Yao, L. Fang, C. Lu, Z. Xu, Near-infrared light-induced sequential shape recovery and separation of assembled temperature memory polymer microparticles, Macromol Rapid Commun 41(8) (2020) e2000043. https://doi.org/10.1002/marc.202000043.
[50] J. Huang, L. Lai, H. Chen, S. Chen, J. Gao, Development of a new shape-memory polymer in the form of microspheres, Materials Letters 225 (2018) 24-27. https://doi.org/10.1016/j.matlet.2018.04.066.
[51] Q. Zhang, T. Sauter, L. Fang, K. Kratz, A. Lendlein, Shape-memory capability of copolyetheresterurethane microparticles prepared via electrospraying, Macromolecular Materials and Engineering 300(5) (2015) 522-530. https://doi.org/10.1002/mame.201400267.
[52] L.M. Cox, J.P. Killgore, Z. Li, Z. Zhang, D.C. Hurley, J. Xiao, Y. Ding, Morphing metal-polymer janus particles, Adv Mater 26(6) (2014) 899-904. https://doi.org/10.1002/adma.201304079.
[53] B. Yan, X. Zheng, P. Tang, H. Yang, J. He, S. Zhou, Investigating switchable nanostructures in shape memory process for amphipathic janus nanoparticles, ACS Appl Mater Interfaces 10(42) (2018) 36249-36258. https://doi.org/10.1021/acsami.8b11276.
[54] J. Zhang, X. Zheng, F. Wu, B. Yan, S. Zhou, S. Qu, J. Weng, Shape memory actuation of janus nanoparticles with amphipathic cross-linked network, ACS Macro Letters 5(12) (2016) 1317-1321. https://doi.org/10.1021/acsmacrolett.6b00730.
[55] U. Mendibil, R. Ruiz-Hernandez, S. Retegi-Carrion, N. Garcia-Urquia, B. Olalde-Graells, A. Abarrategi, Tissue-specific decellularization methods: Rationale and strategies to achieve regenerative compounds, Int J Mol Sci 21(15) (2020). https://doi.org/10.3390/ijms21155447.
[56] D. Choudhury, M. Yee, Z.L.J. Sheng, A. Amirul, M.W. Naing, Decellularization systems and devices: State-of-the-art, Acta Biomater 115 (2020) 51-59. https://doi.org/10.1016/j.actbio.2020.07.060.
[57] T.J. Keane, I.T. Swinehart, S.F. Badylak, Methods of tissue decellularization used for preparation of biologic scaffolds and in vivo relevance, Methods 84 (2015) 25-34. https://doi.org/10.1016/j.ymeth.2015.03.005.
[58] J. Liao, B. Xu, R. Zhang, Y. Fan, H. Xie, X. Li, Applications of decellularized materials in tissue engineering: Advantages, drawbacks and current improvements, and future perspectives, J Mater Chem B 8(44) (2020) 10023-10049. https://doi.org/10.1039/d0tb01534b.
[59] G. Mazza, K. Rombouts, A. Rennie Hall, L. Urbani, T. Vinh Luong, W. Al-Akkad, L. Longato, D. Brown, P. Maghsoudlou, A.P. Dhillon, B. Fuller, B. Davidson, K. Moore, D. Dhar, P. De Coppi, M. Malago, M. Pinzani, Decellularized human liver as a natural 3d-scaffold for liver bioengineering and transplantation, Sci Rep 5 (2015) 13079. https://doi.org/10.1038/srep13079.
[60] B.E. Uygun, A. Soto-Gutierrez, H. Yagi, M.L. Izamis, M.A. Guzzardi, C. Shulman, J. Milwid, N. Kobayashi, A. Tilles, F. Berthiaume, M. Hertl, Y. Nahmias, M.L. Yarmush, K. Uygun, Organ reengineering through development of a transplantable recellularized liver graft using decellularized liver matrix, Nat Med 16(7) (2010) 814-820. https://doi.org/10.1038/nm.2170.
[61] Y. Liu, L. Qin, R. Tong, T. Liu, C. Ling, T. Lei, D. Zhang, Y. Wang, S. Deng, Regulatory changes in china on xenotransplantation and related products, Xenotransplantation 27(3) (2020) e12601. https://doi.org/10.1111/xen.12601.
[62] Y. Gao, Z. Li, Y. Hong, T. Li, X. Hu, L. Sun, Z. Chen, Z. Chen, Z. Luo, X. Wang, J. Kong, G. Li, H.-L. Wang, H.L. Leo, H. Yu, L. Xi, Q. Guo, Decellularized liver as a translucent ex vivo model for vascular embolization evaluation, Biomaterials 240 (2020). https://doi.org/10.1016/j.biomaterials.2020.119855.
[63] X. Gao, Z. Chen, Z. Chen, X. Liu, Y. Luo, J. Xiao, Y. Gao, Y. Ma, C. Liu, H.L. Leo, H. Yu, Q. Guo, Visualization and evaluation of chemoembolization on a 3d decellularized organ scaffold, ACS Biomater Sci Eng 7(12) (2021) 5642-5653. https://doi.org/10.1021/acsbiomaterials.1c01005.
[64] X. Shen, Q. Wang, W. Chen, Y. Pang, One-step synthesis of water-dispersible cysteine functionalized magnetic fe3o4 nanoparticles for mercury(ii) removal from aqueous solutions, Appl. Surf. Sci. 317 (2014) 1028-1034. https://doi.org/10.1016/j.apsusc.2014.09.033.
[65] J.W. Yoo, S. Mitragotri, Polymer particles that switch shape in response to a stimulus, Proc. Natl Acad. Sci. USA 107(25) (2010) 11205-11210. https://doi.org/10.1073/pnas.1000346107.
[66] R.A. Meyer, R.S. Meyer, J.J. Green, An automated multidimensional thin film stretching device for the generation of anisotropic polymeric micro- and nanoparticles, J. Biomed. Mater. Res. A 103(8) (2015) 2747-2757. https://doi.org/10.1002/jbm.a.35399.
[67] R.Z. Li, Time-temperature superposition method for glass transition temperature of plastic materials, Mat Sci Eng a-Struct 278(1-2) (2000) 36-45.
[68] M.L. Williams, R.F. Landel, J.D. Ferry, The temperature dependence of relaxation mechanisms in amorphous polymers and other glass-forming liquids, J. Am. Chem. Soc. 77(14) (1955) 3701-3707. https://doi.org/10.1021/ja01619a008.
[69] P.A. O’Connell, G.B. McKenna, Arrhenius-type temperature dependence of the segmental relaxation below tg, J. Chem. Phys. 110(22) (1999) 11054-11060. https://doi.org/10.1063/1.479046.
[70] E.A. Di Marzio, A.J. Yang, Configurational entropy approach to the kinetics of glasses, J. Res. Natl. Inst. Stand. Technol. 102(2) (1997) 135-157. https://doi.org/10.6028/jres.102.011.
[71] Q. Ge, K. Yu, Y. Ding, H. Jerry Qi, Prediction of temperature-dependent free recovery behaviors of amorphous shape memory polymers, Soft Matter 8(43) (2012) 11098-11105. https://doi.org/10.1039/c2sm26249e.
[72] Y. Gao, Z. Li, Y. Hong, T. Li, X. Hu, L. Sun, Z. Chen, Z. Chen, Z. Luo, X. Wang, J. Kong, G. Li, H.L. Wang, H.L. Leo, H. Yu, L. Xi, Q. Guo, Decellularized liver as a translucent ex vivo model for vascular embolization evaluation, Biomaterials 240 (2020) 119855. https://doi.org/10.1016/j.biomaterials.2020.119855.
[73] W. Nichols, M. O’Rourke, V. C, Properties of the arterial wall: Theory, in: W. Nichols, M. O’Rourke, V. C (Eds.), Mcdonald’s blood flow in arteries theoretical, experimental and clinical principles, CRC Press, London, UK, 2011, pp. 55-75.
[74] S. Umale, S. Chatelin, N. Bourdet, C. Deck, M. Diana, P. Dhumane, L. Soler, J. Marescaux, R. Willinger, Experimental in vitro mechanical characterization of porcine glisson's capsule and hepatic veins, J. Biomech. 44(9) (2011) 1678-1683. https://doi.org/10.1016/j.jbiomech.2011.03.029.
[75] R. Marlow, A general first-invariant hyperelastic constitutive model, in: J. Busfield, A. Muhr (Eds.), Constitutive models for rubber iii: Proceedings of the third european conference on constitutive models for rubber, CRC Press, London, UK, 2003, pp. 157-160.
[76] A. Prasad, N. Xiao, X.Y. Gong, C.K. Zarins, C.A. Figueroa, A computational framework for investigating the positional stability of aortic endografts, Biomech. Model. Mechanobiol. 12(5) (2013) 869-887. https://doi.org/10.1007/s10237-012-0450-3.
[77] S. de Gelidi, G. Tozzi, A. Bucchi, The effect of thickness measurement on numerical arterial models, Mater. Sci. Eng. C Mater. Biol. Appl. 76 (2017) 1205-1215. https://doi.org/10.1016/j.msec.2017.02.123.
[78] Y. Xing, Y. Jia, Z. Zhan, J. Li, C. Hu, A flexible magnetic field mapping model for calibration of magnetic manipulation system, 2021 IEEE International Conference on Robotics and Automation (ICRA), 2021, pp. 7281-7287.
[79] Y. Xing, D. Hussain, C. Hu, Optimized dynamic motion performance for a 5-dof electromagnetic manipulation, IEEE Robotics and Automation Letters 7(4) (2022) 8604-8610. https://doi.org/10.1109/lra.2022.3187501.
[80] K. Yu, Q. Ge, H.J. Qi, Reduced time as a unified parameter determining fixity and free recovery of shape memory polymers, Nat. Commun. 5 (2014) 3066. https://doi.org/10.1038/ncomms4066.
[81] A. Lendlein, S. Kelch, K. Kratz, J. Schulte, Shape-memory polymers, in: K.H.J. Buschow, R.W. Cahn, M.C. Flemings, B. Ilschner, E.J. Kramer, S. Mahajan, P. Veyssière (Eds.), Encyclopedia of materials: Science and technology, Elsevier, Oxford, 2005, pp. 1-9.
[82] J.L. White, J.E. Spruiell, The specification of orientation and its development in polymer processing, Polym. Eng. Sci. 23(5) (1983) 247-256. https://doi.org/DOI 10.1002/pen.760230503.
[83] C. Debbaut, P. Segers, P. Cornillie, C. Casteleyn, M. Dierick, W. Laleman, D. Monbaliu, Analyzing the human liver vascular architecture by combining vascular corrosion casting and micro-ct scanning: A feasibility study, J. Anat. 224(4) (2014) 509-517. https://doi.org/10.1111/joa.12156.
[84] A. Nakai, I. Sekiya, A. Oya, T. Koshino, T. Araki, Assessment of the hepatic arterial and portal venous blood flows during pregnancy with doppler ultrasonography, Arch. Gynecol. Obstet. 266(1) (2002) 25-29. https://doi.org/10.1007/pl00007495.
[85] J.Y. Li, X.J. Li, T. Luo, R. Wang, C.C. Liu, S.X. Chen, D.F. Li, J.B. Yue, S.H. Cheng, D. Sun, Development of a magnetic microrobot for carrying and delivering targeted cells, Sci. Robotics 3(19) (2018) eaat8829. https://doi.org/10.1126/scirobotics.aat8829.
[86] L. Fan, M. Duan, Z. Xie, K. Pan, X. Wang, X. Sun, Q. Wang, W. Rao, J. Liu, Injectable and radiopaque liquid metal/calcium alginate hydrogels for endovascular embolization and tumor embolotherapy, Small 16(2) (2020) e1903421. https://doi.org/10.1002/smll.201903421.
[87] X. Li, X. Ji, K. Chen, M.W. Ullah, X. Yuan, Z. Lei, J. Cao, J. Xiao, G. Yang, Development of finasteride/phbv@polyvinyl alcohol/chitosan reservoir-type microspheres as a potential embolic agent: From in vitro evaluation to animal study, Biomater. Sci. 8(10) (2020) 2797-2813. https://doi.org/10.1039/c9bm01775e.
[88] W. Nichols, M. O’Rourke, V. C, Properties of the arterial wall: Practice, in: W. Nichols, M. O’Rourke, V. C (Eds.), Mcdonald’s blood flow in arteries theoretical, experimental and clinical principles, CRC Press, London, UK, 2011, pp. 77-109.
[89] T.P. Santisakultarm, C.J. Kersbergen, D.K. Bandy, D.C. Ide, S.H. Choi, A.C. Silva, Two-photon imaging of cerebral hemodynamics and neural activity in awake and anesthetized marmosets, J Neurosci Methods 271 (2016) 55-64. https://doi.org/10.1016/j.jneumeth.2016.07.003.
[90] A.K. Gamperl, T.W. Hein, L. Kuo, B.A. Cason, Isoflurane-induced dilation of porcine coronary microvessels is endothelium dependent and inhibited by glibenclamide, Journal of the American Society of Anesthesiologists 96(6) (2002) 1465-1471. https://doi.org/10.1097/00000542-200206000-00028.
[91] H.A. Van Den Brenk, R.D. Chambers, Effects of anaesthetic agents and relaxants on vascular tone studies in sandison clark chambers, Br J Anaesth 28(3) (1956) 98-112. https://doi.org/10.1093/bja/28.3.98.
[92] M. Buscema, S.E. Hieber, G. Schulz, H. Deyhle, A. Hipp, F. Beckmann, J.A. Lobrinus, T. Saxer, B. Muller, Ex vivo evaluation of an atherosclerotic human coronary artery via histology and high-resolution hard x-ray tomography, Sci Rep 9(1) (2019) 14348. https://doi.org/10.1038/s41598-019-50711-1.
[93] M. Cooley, A. Sarode, M. Hoore, D.A. Fedosov, S. Mitragotri, A. Sen Gupta, Influence of particle size and shape on their margination and wall-adhesion: Implications in drug delivery vehicle design across nano-to-micro scale, Nanoscale 10(32) (2018) 15350-15364. https://doi.org/10.1039/c8nr04042g.
[94] A. Da Silva-Candal, T. Brown, V. Krishnan, I. Lopez-Loureiro, P. Avila-Gomez, A. Pusuluri, A. Perez-Diaz, C. Correa-Paz, P. Hervella, J. Castillo, S. Mitragotri, F. Campos, Shape effect in active targeting of nanoparticles to inflamed cerebral endothelium under static and flow conditions, J. Control. Release 309 (2019) 94-105. https://doi.org/10.1016/j.jconrel.2019.07.026.
[95] R. Gupta, Y. Badhe, S. Mitragotri, B. Rai, Permeation of nanoparticles across the intestinal lipid membrane: Dependence on shape and surface chemistry studied through molecular simulations, Nanoscale 12(11) (2020) 6318-6333. https://doi.org/10.1039/c9nr09947f.
[96] P.A. James, S. Oparil, B.L. Carter, W.C. Cushman, C. Dennison-Himmelfarb, J. Handler, D.T. Lackland, M.L. LeFevre, T.D. MacKenzie, O. Ogedegbe, S.C. Smith, Jr., L.P. Svetkey, S.J. Taler, R.R. Townsend, J.T. Wright, Jr., A.S. Narva, E. Ortiz, 2014 evidence-based guideline for the management of high blood pressure in adults: Report from the panel members appointed to the eighth joint national committee (jnc 8), JAMA 311(5) (2014) 507-520. https://doi.org/10.1001/jama.2013.284427.
[97] K. Varghese, S. Adhyapak, Therapeutic embolization, Springer International Publishing, Switzerland, 2017.
[98] M. Caine, D. Carugo, X. Zhang, M. Hill, M.R. Dreher, A.L. Lewis, Review of the development of methods for characterization of microspheres for use in embolotherapy: Translating bench to cathlab, Adv. Healthcare Mater. 6(9) (2017) 1601291. https://doi.org/10.1002/adhm.201601291.