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Functional block copolymers bearing pendant cinnamyl groups for enhanced solubilization of caffeic acid phenethyl ester

Abstract

The natural bioactive compound caffeic acid phenethyl ester (CAPE) possesses antioxidant, antiinflammatory and anticancer activity. However, the in vivo application of CAPE is limited due to its poor solubility in aqueous media. In this contribution, we report a strategy for enhancing the solubility of CAPE in water by novel micellar carriers comprising segments structurally similar to the CAPE molecule. A series of amphiphilic poly(ethylene oxide)-b-poly(α-cinnamyl-ε-caprolactone-co-ε-caprolactone)-b-poly(ethylene oxide) (PEO-b-P(CyCL-co-CL)-b-PEO) triblock copolymers were synthesized by combining ring-opening copolymerization and “click” reactions. Calculations of the Flory–Huggins parameter suggested that P(CyCL-co-CL) copolymers have a higher affinity for CAPE than do PCL polymer. Micellar carriers based on PEO-b-P(CyCL-co-CL)-b-PEO were formed via the solvent evaporation method and then loaded with CAPE. Dynamic light scattering (DLS) and cryogenic transmission electron microscopy (cryo-TEM) revealed the formation of nanosized spherical micelles that maintained their structural integrity upon dilution to 0.055–0.06 g L−1. The main characteristics of the PEO-b-P(CyCL-co-CL)-b-PEO systems were compared to those of the PEO-b-PCL-b-PEO system. The attachment of pendant cinnamyl moieties to the hydrophobic PCL block enhanced the encapsulation efficiency of the micelles and reduced their burst release behavior.

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Scheme 1
Fig. 1: 1H-NMR spectra of the precursors and hydrophobic macroreagent in CDCl3.
Fig. 2: 1H-NMR spectrum of the amphiphilic triblock copolymer in CDCl3.
Fig. 3: GPC chromatograms of the two macroreagents and the amphiphilic triblock copolymer.
Fig. 4: Preparation of CAPE-loaded polymeric micelles.
Fig. 5: Hydrodynamic diameter distribution of blank block copolmer micelles.
Fig. 6: Cryo-TEM micrographs and the corresponding histograms of block copolymer micelles in water.
Fig. 7: In vitro release of CAPE from block copolymer micelles in phosphate buffer (pH = 7.4).
Fig. 8: In vitro toxicity evaluation of blank micelles, pure drug and drug-loaded micelles.

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References

  1. Cabral H, Miyata K, Osada K, Kataoka K. Block copolymer micelles in nanomedicine applications. Chem Rev. 2018;118:6844–92.

    Article  CAS  Google Scholar 

  2. Deshmukh AS, Chauhan PN, Noolvi MN, Chaturvedi K, Ganguly K, Shukla SS, et al. Polymeric micelles: Basic research to clinical practice. Int J Pharm. 2017;532:249–68.

    Article  CAS  Google Scholar 

  3. Gong J, Chen M, Zheng Y, Wang S, Wang Y. Polymeric micelles drug delivery system in oncology. J Control Release. 2012;159:312–23.

    Article  CAS  Google Scholar 

  4. Cabral H, Kataoka K. Progress of drug-loaded polymeric micelles into clinical studies. J Control Release. 2014;190:465–76.

    Article  CAS  Google Scholar 

  5. Danson S, Ferry D, Alakhov V, Margison J, Kerr D, Jowle D, et al. Phase I dose escalation and pharmacokinetic study of pluronic polymer-bound doxorubicin (SP1049C) in patients with advanced cancer. Br J Cancer. 2004;90:2085–91.

    Article  CAS  Google Scholar 

  6. Allen TM. Ligand-targeted therapeutics in anticancer therapy. Nat Rev Cancer. 2002;2:750–63.

    Article  CAS  Google Scholar 

  7. Miyata K, Kakizawa Y, Nishiyama N, Yamasaki Y, Watanabe T, Kohara M, et al. Freeze-dried formulations for in vivo gene delivery of PEGylated polyplex micelles with disulfide crosslinked cores to the liver. J Control Release. 2005;109:15–23.

    Article  CAS  Google Scholar 

  8. Lavasanifar A, Samuel J, Sattari S, Kwon GS. Block copolymer micelles for the encapsulation and delivery of Amphotericin B. Pharm Res. 2002;19:418–22.

    Article  CAS  Google Scholar 

  9. Falamarzian A, Lavasanifar A. Chemical modification of hydrophobic block in poly(ethylene oxide) poly(caprolactone) based nanocarriers: Еffect on the solubilization and hemolytic activity of Amphotericin B. Macromol Biosci. 2010;10:648–56.

    Article  CAS  Google Scholar 

  10. Falamarzian A, Lavasanifar A. Optimization of the hydrophobic domain in poly(ethylene oxide)-poly(-caprolactone) based nano-carriers for the solubilization and delivery of Amphotericin B. Colloids Surf B: Biointerfaces. 2010;81:313–20.

    Article  CAS  Google Scholar 

  11. Mahmud A, Patel S, Molavi O, Choi P, Samuel J, Lavasanifar A. Self-associating poly(ethylene oxide)-b-poly(α-cholesteryl carboxylate-ε-caprolactone) block copolymer for the solubilization of stat-3 inhibitor Cucurbitacin I. Biomacromolecules. 2009;10:471–8.

    Article  CAS  Google Scholar 

  12. Chen Y-J, Shiao MS, Wang SY. The antioxidant caffeic acid phenethyl ester induces apoptosis associated with selective scavenging of hydrogen peroxide in human leukemic HL-60 cells. Anti-Cancer Drugs. 2001;12:143–9.

    Article  CAS  Google Scholar 

  13. Orban Z, Mitsiades N, Burke TR Jr, Tsokos M, Chrousos GP. Caffeic acid phenethyl ester induces leukocyte apoptosis, modulates nuclear factor-kappa B and suppresses acute inflammation. Neuroimmunomodulation. 2000;7:99–105.

    Article  CAS  Google Scholar 

  14. Akyol S, Ozturk G, Ginis Z, Armutcu F, Yigitoglu MR, Akyol O. In vivo and in vitro antineoplastic actions of caffeic acid phenethyl ester (CAPE): therapeutic perspectives. Nutr Cancer. 2013;65:515–26.

    Article  CAS  Google Scholar 

  15. Tsai TH, Yu CH, Chang YP, Lin YT, Huang CJ, Kuo YH, et al. Protective effect of caffeic acid derivatives on tert-butyl hydroperoxideinduced oxidative hepato-toxicity and mitochondrial dysfunction in HepG2 cells. Molecules. 2017;22:702.

    Article  Google Scholar 

  16. Derman S. Caffeic acid phenethyl ester loaded PLGA nanoparticles: effect of various process parameters on reaction yield, encapsulation efficiency, and particle size. J Nanomater. 2015; 341848. https://www.hindawi.com/journals/jnm/2015/341848/cta/

  17. Lee HY, Jeong YI, Kim EJ, Lee KD, Choi SH, Kim YJ, et al. Preparation of caffeic acid phenethyl ester-incorporated nanoparticles and their biological activity. J Pharm Sci. 2015;104:144–54.

    Article  CAS  Google Scholar 

  18. Yoncheva K, Tzankova V, Yordanov Y, Tzankov B, Grancharov G, Aluani D, et al. Evaluation of antioxidant activity of caffeic acid phenethyl ester loaded block copolymer micelles. Biotechnol Biotechnol Equip. 2019;33:64–74.

    Article  Google Scholar 

  19. Darcos V, El Habnouni S, Nottelet B, El Ghzaoui A, Coudane J. Well-defined PCL-graft-PDMAEMA prepared by ring-opening polymerisation and click chemistry. Polym Chem. 2010;1:280–2.

    Article  CAS  Google Scholar 

  20. Flory PJ. Principle of polymer chemistry. Ithaca, NY: Cornell University Press; 1953.

    Google Scholar 

  21. Fedors RF. A method for estimating both the solubility parameters and molar volumes of liquids. J Polym Eng Sci. 1974;14:147–54.

    Article  CAS  Google Scholar 

  22. Kolb HC, Finn MG, Sharpless KB. Click chemistry: diverse chemical function from a few good reactions. Angew Chem Int Ed. 2001;40:2004–21.

    Article  CAS  Google Scholar 

  23. Parrish B, Breitenkamp R, Emrick T. PEG- and peptide-grafted aliphatic polyesters by click chemistry. J Am Chem Soc. 2005;127:7404–10.

    Article  CAS  Google Scholar 

  24. Quaglia F, Ostacolo L, De Rosa G, La Rotonda MI, Ammendola M, Nese G, et al. Nanoscopic core-shell drug carriers made of amphiphilic triblock and star-diblock copolymers. Int J Pharm. 2006;324:56–66.

    Article  CAS  Google Scholar 

  25. Samad A, Bakkour Y, Fanny C, Omar F, Coudane J, Nottelet B. From nanospheres to micelles: simple control of PCL-g-PEG copolymers amphiphilicity through thiol-yne photografting. Polym Chem. 2015;6:5093–102.

    Article  Google Scholar 

  26. ISO 10993-5:2009. Biological evaluation of medical devices–Part 5: Tests for in vitro cytotoxicity. International Organization for Standardization. 2009. https://www.iso.org/standard/36406.html. Accessed 26 Sept 2019.

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Acknowledgements

This work was supported by the Bulgarian National Science Fund [Grant number DN 09-1/2016]. The authors thank Mrs R. Radeva and Dr Ch. Novakov for GPC measurements.

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Correspondence to Petar D. Petrov.

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Grancharov, G., Atanasova, MD., Aluani, D. et al. Functional block copolymers bearing pendant cinnamyl groups for enhanced solubilization of caffeic acid phenethyl ester. Polym J 52, 435–447 (2020). https://doi.org/10.1038/s41428-019-0297-x

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