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Biological membrane derived nanomedicines for cancer therapy

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Abstract

The development of nanomedicine systems for applications in cancer therapies has been widely explored in the last decade. With inherent biocompatibility, nanomedicine devices derived from biological membranes have shown many unique advantages compared with traditional artificial nanomaterials for biomedical applications. Herein, we present a comprehensive review of the recent development of cell membrane derived nanomedicines in cancer treatment. We firstly outline the advantages of biological membranes in nanomedicine design derived from their intrinsic characteristics, and then discuss the applications of biological membrane derived nanomedicines. For the first major category of membrane-derived nanomedicine, synthetic nanoparticles are usually camouflaged with cell membranes to acquire additional functionalities. The other type of membrane-based nanomedicine is directly using the engineered cell membrane-derived vesicles or nanovesicles secreted by cells for tumor treatment. At last, we discuss the challenges of membrane-derived nanomedicines towards future clinical applications, following with perspectives on possible solutions to the current problems.

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References

  1. Miller KD, Siegel RL, Lin CC, Mariotto AB, Kramer JL, Rowland JH, Stein KD, Alteri R, Jemal A. CA Cancer J, 2016, 66: 271–289

    Article  Google Scholar 

  2. Gu L, Mooney DJ. Nat Rev Cancer, 2016, 16: 56–66

    Article  Google Scholar 

  3. Yu B, Goel S, Ni D, Ellison PA, Siamof CM, Jiang D, Cheng L, Kang L, Yu F, Liu Z, Barnhart TE, He Q, Zhang H, Cai W. Adv Mater, 2018, 30: 1704934

    Article  Google Scholar 

  4. Wang C, Li Z, Cao D, Zhao YL, Gaines JW, Bozdemir OA, Ambrogio MW, Frasconi M, Botros YY, Zink JI, Stoddart JF. Angew Chem Int Ed, 2012, 51: 5460–5465

    Article  Google Scholar 

  5. Maeda H. Adv Drug Deliver Rev, 2015, 91: 3–6

    Article  Google Scholar 

  6. Barenholz YC. J Control Release, 2012, 160: 117–134

    Article  Google Scholar 

  7. Sofias AM, Dunne M, Storm G, Allen C. Adv Drug Deliver Rev, 2017, 122: 20–30

    Article  Google Scholar 

  8. Bertrand N, Wu J, Xu X, Kamaly N, Farokhzad OC. Adv Drug Deliver Rev, 2014, 66: 2–25

    Article  Google Scholar 

  9. Kemp JA, Shim MS, Heo CY, Kwon YJ. Adv Drug Deliver Rev, 2016, 98: 3–18

    Article  Google Scholar 

  10. Kwiatkowski S, Knap B, Przystupski D, Saczko J, Kędzierska E, Knap-Czop K, Kotlińska J, Michel O, Kotowski K, Kulbacka J. Biomed Pharmacother, 2018, 106: 1098–1107

    Article  Google Scholar 

  11. Masood F. Mater Sci Eng-C, 2016, 60: 569–578

    Article  Google Scholar 

  12. Hu Y, Mignani S, Majoral JP, Shen M, Shi X. Chem Soc Rev, 2018, 47: 1874–1900

    Article  Google Scholar 

  13. Zarschler K, Rocks L, Licciardello N, Boselli L, Polo E, Garcia KP, De Cola L, Stephan H, Dawson KA. Nanomed, 2016, 12: 1663–1701

    Article  Google Scholar 

  14. Mandal B, Bhattacharjee H, Mittal N, Sah H, Balabathula P, Thoma LA, Wood GC. Nanomed, 2013, 9: 474–491

    Article  Google Scholar 

  15. Karakoti AS, Das S, Thevuthasan S, Seal S. Angew Chem Int Ed, 2011, 50: 1980–1994

    Article  Google Scholar 

  16. Moghimi SM, Hunter AC, Andresen TL. Annu Rev Pharmacol Toxicol, 2012, 52: 481–503

    Article  Google Scholar 

  17. Liu WL, Zou MZ, Qin SY, Cheng YJ, Ma YH, Sun YX, Zhang XZ. Adv Funct Mater, 2020, 30: 2003559

    Article  Google Scholar 

  18. Zhen X, Cheng P, Pu K. Small, 2019, 15: 1804105

    Article  Google Scholar 

  19. Pegtel DM, Gould SJ. Annu Rev Biochem, 2019, 88: 487–514

    Article  Google Scholar 

  20. Li R, He Y, Zhang S, Qin J, Wang J. Acta Pharm Sin B, 2018, 8: 14–22

    Article  Google Scholar 

  21. Maas SLN, Breakefield XO, Weaver AM. Trends Cell Biol, 2017, 27: 172–188

    Article  Google Scholar 

  22. Gao M, Liang C, Song X, Chen Q, Jin Q, Wang C, Liu Z. Adv Mater, 2017, 29: 1701429

    Article  Google Scholar 

  23. Rao L, Bu LL, Meng QF, Cai B, Deng WW, Li A, Li K, Guo SS, Zhang WF, Liu W, Sun ZJ, Zhao XZ. Adv Funct Mater, 2017, 27: 1604774

    Article  Google Scholar 

  24. Huang Y, Mei C, Tian Y, Nie T, Liu Z, Chen T. NPG Asia Mater, 2018, 10: 1002–1015

    Article  Google Scholar 

  25. Yang R, Xu J, Xu L, Sun X, Chen Q, Zhao Y, Peng R, Liu Z. ACS Nano, 2018, 12: 5121–5129

    Article  Google Scholar 

  26. Liu J, Chen Q, Feng L, Liu Z. Nano Today, 2018, 21: 55–73

    Article  Google Scholar 

  27. Han X, Shen S, Fan Q, Chen G, Archibong E, Dotti G, Liu Z, Gu Z, Wang C. Sci Adv, 2019, 5: eaaw6870

    Article  Google Scholar 

  28. Zhang X, Wang C, Wang J, Hu Q, Langworthy B, Ye Y, Sun W, Lin J, Wang T, Fine J, Cheng H, Dotti G, Huang P, Gu Z. Adv Mater, 2018, 30: 1707112

    Article  Google Scholar 

  29. Kim HY, Kang M, Choo YW, Go SH, Kwon SP, Song SY, Sohn HS, Hong J, Kim BS. Nano Lett, 2019, 19: 5185–5193

    Article  Google Scholar 

  30. Yong T, Zhang X, Bie N, Zhang H, Zhang X, Li F, Hakeem A, Hu J, Gan L, Santos HA, Yang X. Nat Commun, 2019, 10: 3838

    Article  Google Scholar 

  31. Lv P, Liu X, Chen X, Liu C, Zhang Y, Chu C, Wang J, Wang X, Chen X, Liu G. Nano Lett, 2019, 19: 2993–3001

    Article  Google Scholar 

  32. Nam GH, Choi Y, Kim GB, Kim S, Kim SA, Kim IS. Adv Mater, 2020, 32: 2002440

    Article  Google Scholar 

  33. Kim OY, Park HT, Dinh NTH, Choi SJ, Lee J, Kim JH, Lee SW, Gho YS. Nat Commun, 2017, 8: 626

    Article  Google Scholar 

  34. Chen Q, Bai H, Wu W, Huang G, Li Y, Wu M, Tang G, Ping Y. Nano Lett, 2020, 20: 11–21

    Article  Google Scholar 

  35. Hong Y, Nam GH, Koh E, Jeon S, Kim GB, Jeong C, Kim DH, Yang Y, Kim IS. Adv Funct Mater, 2018, 28: 1703074

    Article  Google Scholar 

  36. Murray S, O’Brien R, Mattson K, Ceccarelli C, Sykora R, West K, Davis Jr. J. Angew Chem Int Ed, 2010, 49: 2755–2758

    Article  Google Scholar 

  37. Fang RH, Kroll AV, Gao W, Zhang L. Adv Mater, 2018, 30: 1706759

    Article  Google Scholar 

  38. EL Andaloussi S, Mäger I, Breakefield XO, Wood MJA. Nat Rev Drug Discov, 2013, 12: 347–357

    Article  Google Scholar 

  39. Hu CMJ, Fang RH, Zhang L. Adv Healthc Mater, 2012, 1: 537–547

    Article  Google Scholar 

  40. Fang RH, Hu CMJ, Zhang L. Expert Opin Biol Ther, 2012, 12: 385–389

    Article  Google Scholar 

  41. Gao W, Hu CMJ, Fang RH, Luk BT, Su J, Zhang L. Adv Mater, 2013, 25: 3549–3553

    Article  Google Scholar 

  42. Fang RH, Hu CMJ, Luk BT, Gao W, Copp JA, Tai Y, O’Connor DE, Zhang L. Nano Lett, 2014, 14: 2181–2188

    Article  Google Scholar 

  43. Gao W, Fang RH, Thamphiwatana S, Luk BT, Li J, Angsantikul P, Zhang Q, Hu CMJ, Zhang L. Nano Lett, 2015, 15: 1403–1409

    Article  Google Scholar 

  44. Hu CMJ, Fang RH, Wang KC, Luk BT, Thamphiwatana S, Dehaini D, Nguyen P, Angsantikul P, Wen CH, Kroll AV, Carpenter C, Ramesh M, Qu V, Patel SH, Zhu J, Shi W, Hofman FM, Chen TC, Gao W, Zhang K, Chien S, Zhang L. Nature, 2015, 526: 118–121

    Article  Google Scholar 

  45. Chen Z, Hu Q, Gu Z. Acc Chem Res, 2018, 51: 668–677

    Article  Google Scholar 

  46. Wu M, Liu X, Bai H, Lai L, Chen Q, Huang G, Liu B, Tang G. ACS Appl Mater Interfaces, 2019, 11: 9850–9859

    Article  Google Scholar 

  47. Yan H, Shao D, Lao YH, Li M, Hu H, Leong KW. Adv Sci, 2019, 6: 1900605

    Article  Google Scholar 

  48. Qiu WX, Zhang MK, Liu LH, Gao F, Zhang L, Li SY, Xie BR, Zhang C, Feng J, Zhang XZ. Biomaterials, 2018, 161: 81–94

    Article  Google Scholar 

  49. Fan Z, Zhou H, Li PY, Speer JE, Cheng H. J Mater Chem B, 2014, 2: 8231–8238

    Article  Google Scholar 

  50. Pei Q, Hu X, Zheng X, Liu S, Li Y, Jing X, Xie Z. ACS Nano, 2018, 12: 1630–1641

    Article  Google Scholar 

  51. Zhang N, Li M, Sun X, Jia H, Liu W. Biomaterials, 2018, 159: 25–36

    Article  Google Scholar 

  52. Duan Y, Wu M, Hu D, Pan Y, Hu F, Liu X, Thakor N, Ng WH, Liu X, Sheng Z, Zheng H, Liu B. Adv Funct Mater, 2020, 30: 2004346

    Article  Google Scholar 

  53. Wang F, Fang RH, Luk BT, Hu CMJ, Thamphiwatana S, Dehaini D, Angsantikul P, Kroll AV, Pang Z, Gao W, Lu W, Zhang L. Adv Funct Mater, 2016, 26: 1628–1635

    Article  Google Scholar 

  54. Rao L, Cai B, Bu LL, Liao QQ, Guo SS, Zhao XZ, Dong WF, Liu W. ACS Nano, 2017, 11: 3496–3505

    Article  Google Scholar 

  55. Villa CH, Anselmo AC, Mitragotri S, Muzykantov V. Adv Drug Deliver Rev, 2016, 106: 88–103

    Article  Google Scholar 

  56. Yoo JW, Irvine DJ, Discher DE, Mitragotri S. Nat Rev Drug Discov, 2011, 10: 521–535

    Article  Google Scholar 

  57. Harris AL. Nat Rev Cancer, 2002, 2: 38–47

    Article  Google Scholar 

  58. Carmeliet P, Jain RK. Nature, 2011, 473: 298–307

    Article  Google Scholar 

  59. Leamon CP, Reddy JA. Adv Drug Deliver Rev, 2004, 56: 1127–1141

    Article  Google Scholar 

  60. Pei Q, Hu X, Zhou J, Liu S, Xie Z. Biomater Sci, 2017, 5: 1517–1521

    Article  Google Scholar 

  61. Yuan Y, Liu J, Liu B. Angew Chem Int Ed, 2014, 53: 7163–7168

    Article  Google Scholar 

  62. Yang W, Guo W, Le W, Lv G, Zhang F, Shi L, Wang X, Wang J, Wang S, Chang J, Zhang B. ACS Nano, 2016, 10: 10245–10257

    Article  Google Scholar 

  63. Ding H, Cai Y, Gao L, Liang M, Miao B, Wu H, Liu Y, Xie N, Tang A, Fan K, Yan X, Nie G. Nano Lett, 2019, 19: 203–209

    Article  Google Scholar 

  64. Smith BR, Gambhir SS. Chem Rev, 2017, 117: 901–986

    Article  Google Scholar 

  65. Kim K, Kim JH, Park H, Kim YS, Park K, Nam H, Lee S, Park JH, Park RW, Kim IS, Choi K, Kim SY, Park K, Kwon IC. J Control Release, 2010, 146: 219–227

    Article  Google Scholar 

  66. You Y, He L, Ma B, Chen T. Adv Funct Mater, 2017, 27: 1703313

    Article  Google Scholar 

  67. Rao L, Yu G, Meng Q, Bu L, Tian R, Lin L, Deng H, Yang W, Zan M, Ding J, Li A, Xiao H, Sun Z, Liu W, Chen X. Adv Funct Mater, 2019, 29: 1905671

    Article  Google Scholar 

  68. Batrakova EV, Gendelman HE, Kabanov AV. Expert Opin Drug Deliver, 2011, 8: 415–433

    Article  Google Scholar 

  69. Li SY, Cheng H, Xie BR, Qiu WX, Zeng JY, Li CX, Wan SS, Zhang L, Liu WL, Zhang XZ. ACS Nano, 2017, 11: 7006–7018

    Article  Google Scholar 

  70. Xu J, Lv J, Zhuang Q, Yang Z, Cao Z, Xu L, Pei P, Wang C, Wu H, Dong Z, Chao Y, Wang C, Yang K, Peng R, Cheng Y, Liu Z. Nat Nanotechnol, 2020, 15: 1043–1052

    Article  Google Scholar 

  71. Gonzalez H, Hagerling C, Werb Z. Genes Dev, 2018, 32: 1267–1284

    Article  Google Scholar 

  72. Joyce JA, Fearon DT. Science, 2015, 348: 74–80

    Article  Google Scholar 

  73. Ferreira LMR, Muller YD, Bluestone JA, Tang Q. Nat Rev Drug Discov, 2019, 18: 749–769

    Article  Google Scholar 

  74. Han Y, Pan H, Li W, Chen Z, Ma A, Yin T, Liang R, Chen F, Ma Y, Jin Y, Zheng M, Li B, Cai L. Adv Sci, 2019, 6: 1900251

    Article  Google Scholar 

  75. Wang H, Wang R, Cai K, He H, Liu Y, Yen J, Wang Z, Xu M, Sun Y, Zhou X, Yin Q, Tang L, Dobrucki IT, Dobrucki LW, Chaney EJ, Boppart SA, Fan TM, Lezmi S, Chen X, Yin L, Cheng J. Nat Chem Biol, 2017, 13: 415–424

    Article  Google Scholar 

  76. Chen Z, Zhao P, Luo Z, Zheng M, Tian H, Gong P, Gao G, Pan H, Liu L, Ma A, Cui H, Ma Y, Cai L. ACS Nano, 2016, 10: 10049–10057

    Article  Google Scholar 

  77. Lee S, Koo H, Na JH, Han SJ, Min HS, Lee SJ, Kim SH, Yun SH, Jeong SY, Kwon IC, Choi K, Kim K. ACS Nano, 2014, 8: 2048–2063

    Article  Google Scholar 

  78. Li W, Pan H, He H, Meng X, Ren Q, Gong P, Jiang X, Liang Z, Liu L, Zheng M, Shao X, Ma Y, Cai L. Small, 2019, 15: 1804383

    Article  Google Scholar 

  79. Huang R, Wang X, Zhou Y, Xiao Y. Bone Res, 2017, 5: 17019

    Article  Google Scholar 

  80. Lanier LL. Annu Rev Immunol, 2005, 23: 225–274

    Article  Google Scholar 

  81. Shimasaki N, Jain A, Campana D. Nat Rev Drug Discov, 2020, 19: 200–218

    Article  Google Scholar 

  82. Deng G, Sun Z, Li S, Peng X, Li W, Zhou L, Ma Y, Gong P, Cai L. ACS Nano, 2018, 12: 12096–12108

    Article  Google Scholar 

  83. Wang C, Wang Y, Zhang L, Miron RJ, Liang J, Shi M, Mo W, Zheng S, Zhao Y, Zhang Y. Adv Mater, 2018, 30: 1804023

    Article  Google Scholar 

  84. Zhang Y, Cai K, Li C, Guo Q, Chen Q, He X, Liu L, Zhang Y, Lu Y, Chen X, Sun T, Huang Y, Cheng J, Jiang C. Nano Lett, 2018, 18: 1908–1915

    Article  Google Scholar 

  85. He H, Guo C, Wang J, Korzun WJ, Wang XY, Ghosh S, Yang H. Nano Lett, 2018, 18: 6164–6174

    Article  Google Scholar 

  86. Kumar S, Han J, Michael IJ, Ki D, Sunkara V, Park J, Gautam S, Ha HK, Zhang L, Cho Y. Adv Funct Mater, 2019, 29: 1902669

    Article  Google Scholar 

  87. Nagasaki E, Takahara A, Koido S, Sagawa Y, Aiba K, Tajiri H, Yagita H, Homma S. J ImmunoTher, 2010, 33: 467–474

    Article  Google Scholar 

  88. Li D, Li Y, Xing H, Guo J, Ping Y, Tang G. Adv Funct Mater, 2014, 24: 5482–5492

    Article  Google Scholar 

  89. Sahai E, Astsaturov I, Cukierman E, DeNardo DG, Egeblad M, Evans RM, Fearon D, Greten FR, Hingorani SR, Hunter T, Hynes RO, Jain RK, Janowitz T, Jorgensen C, Kimmelman AC, Kolonin MG, Maki RG, Powers RS, Puré E, Ramirez DC, Scherz-Shouval R, Sherman MH, Stewart S, Tlsty TD, Tuveson DA, Watt FM, Weaver V, Weeraratna AT, Werb Z. Nat Rev Cancer, 2020, 20: 174–186

    Article  Google Scholar 

  90. Li J, Zhen X, Lyu Y, Jiang Y, Huang J, Pu K. ACS Nano, 2018, 12: 8520–8530

    Article  Google Scholar 

  91. Miao Q, Yeo DC, Wiraja C, Zhang J, Ning X, Xu C, Pu K. Angew Chem Int Ed, 2018, 57: 1256–1260

    Article  Google Scholar 

  92. Marvel D, Gabrilovich DI. J Clin Invest, 2015, 125: 3356–3364

    Article  Google Scholar 

  93. Yu GT, Rao L, Wu H, Yang LL, Bu LL, Deng WW, Wu L, Nan X, Zhang WF, Zhao XZ, Liu W, Sun ZJ. Adv Funct Mater, 2018, 28: 1801389

    Article  Google Scholar 

  94. Shayakhmetov DM, Li ZY, Ni S, Lieber A. J Virol, 2004, 78: 5368–5381

    Article  Google Scholar 

  95. Jiang Q, Liu Y, Guo R, Yao X, Sung S, Pang Z, Yang W. Biomaterials, 2019, 192: 292–308

    Article  Google Scholar 

  96. Bu L, Rao L, Yu G, Chen L, Deng W, Liu J, Wu H, Meng Q, Guo S, Zhao X, Zhang W, Chen G, Gu Z, Liu W, Sun Z. Adv Funct Mater, 2019, 29: 1807733

    Article  Google Scholar 

  97. Rao L, Meng QF, Huang Q, Wang Z, Yu GT, Li A, Ma W, Zhang N, Guo SS, Zhao XZ, Liu K, Yuan Y, Liu W. Adv Funct Mater, 2018, 28: 1803531

    Article  Google Scholar 

  98. Dehaini D, Wei X, Fang RH, Masson S, Angsantikul P, Luk BT, Zhang Y, Ying M, Jiang Y, Kroll AV, Gao W, Zhang L. Adv Mater, 2017, 29: 1606209

    Article  Google Scholar 

  99. Wolf P. Br J Haematol, 1967, 13: 269–288

    Article  Google Scholar 

  100. van Dommelen SM, Vader P, Lakhal S, Kooijmans SAA, van Solinge WW, Wood MJA, Schiffelers RM. J Control Release, 2012, 161: 635–644

    Article  Google Scholar 

  101. Xu R, Greening DW, Rai A, Ji H, Simpson RJ. Methods, 2015, 87: 11–25

    Article  Google Scholar 

  102. Kowal J, Tkach M, Théry C. Curr Opin Cell Biol, 2014, 29: 116–125

    Article  Google Scholar 

  103. Xu R, Rai A, Chen M, Suwakulsiri W, Greening DW, Simpson RJ. Nat Rev Clin Oncol, 2018, 15: 617–638

    Article  Google Scholar 

  104. Wang J, Dong Y, Li Y, Li W, Cheng K, Qian Y, Xu G, Zhang X, Hu L, Chen P, Du W, Feng X, Zhao YD, Zhang Z, Liu BF. Adv Funct Mater, 2018, 28: 1707360

    Article  Google Scholar 

  105. Hribar KC, Lee MH, Lee D, Burdick JA. ACS Nano, 2011, 5: 2948–2956

    Article  Google Scholar 

  106. Zhou H, Fan Z, Deng J, Lemons PK, Arhontoulis DC, Bowne WB, Cheng H. Nano Lett, 2016, 16: 3268–3277

    Article  Google Scholar 

  107. Koh E, Lee EJ, Nam GH, Hong Y, Cho E, Yang Y, Kim IS. Biomaterials, 2017, 121: 121–129

    Article  Google Scholar 

  108. Ing R, Segura M, Thawani N, Tam M, Stevenson MM. J Immunol, 2006, 176: 441–450

    Article  Google Scholar 

  109. Parker BS, Rautela J, Hertzog PJ. Nat Rev Cancer, 2016, 16: 131–144

    Article  Google Scholar 

  110. Lee CH, Wu CL, Shiau AL. Clin Cancer Res, 2008, 14: 1905–1912

    Article  Google Scholar 

  111. Li Y, Zhao R, Cheng K, Zhang K, Wang Y, Zhang Y, Li Y, Liu G, Xu J, Xu J, Anderson GJ, Shi J, Ren L, Zhao X, Nie G. ACS Nano, 2020, 14: 16698–16711

    Article  Google Scholar 

  112. Zhuang Q, Xu J, Deng D, Chao T, Li J, Zhang R, Peng R, Liu Z. Biomaterials, 2021, 268: 120550

    Article  Google Scholar 

  113. Teijaro JR. Semin Immunopathol, 2017, 39: 501–503

    Article  Google Scholar 

  114. Munn DH, Mellor AL. J Clin Invest, 2007, 117: 1147–1154

    Article  Google Scholar 

  115. Chen D, Yang D, Dougherty CA, Lu W, Wu H, He X, Cai T, Van Dort ME, Ross BD, Hong H. ACS Nano, 2017, 11: 4315–4327

    Article  Google Scholar 

  116. Cheng X, Lee RJ. Adv Drug Deliver Rev, 2016, 99: 129–137

    Article  Google Scholar 

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Acknowledgements

This work was partially supported by the National Research Programs from Ministry of Science and Technology of China (2016YFA0201200), the National Natural Science Foundation of China (21907073, 52032008), the Jiangsu Social Development Project (BE2019658), Collaborative Innovation Center of Suzhou Nano Science and Technology, the “111” program from the Ministry of Education of China and the Key Scientific and Technological Projects of Henan Province of China (192102310071).

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Sun, L., Xiong, Z., Shen, F. et al. Biological membrane derived nanomedicines for cancer therapy. Sci. China Chem. 64, 719–733 (2021). https://doi.org/10.1007/s11426-020-9943-9

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