高分子可用於植入缺損部位的三維（3-D）多孔支架結構，因此在組織工程中引起了很多興趣。由於高分子顆粒具有高表面積與體積比，因此小體積的高分子球型顆粒能提供高單位體積細胞產量。在此研究中 以懸浮聚合法和乳化聚合法，成功地合成了微米級和奈米級的Poly(HEMA)顆粒。在微米顆粒中，將帶正電的DEAEMA單體與HEMA單體進行無規共聚，以增強細胞在顆粒上的附著力。此外將殼聚糖塗覆在Poly(HEMA)微米顆粒表面，以增加高分子的生物相容性。為了增 強細胞與高分子顆粒間的作用力，成功合成了平均直徑為400微米的多孔性Poly(HEMA)顆粒。為了比較粒徑大小的影響，還合成了平均直徑為650 奈米的Poly(HEMA)顆粒，在Poly(HEMA)微米顆粒中添加DEAEMA單體可增強高分子的熱穩定性，根據熱重分析不含有與含有DEAEMA的Poly(HEMA)微米顆粒的裂解溫度分別為204℃和275℃。Poly(HEMA)微米顆粒中含有陽離子單體，明顯地促進了L929細胞的黏附及生長。殼聚糖塗覆的Poly(HEMA）微米顆粒，也顯著增加了L929細胞的黏附及生長數量。實驗結果顯示，在具有0.02 莫爾 DEAEMA和殼聚糖塗層的Poly(HEMA)微米顆粒，可獲得最佳的細胞黏附及生長。另外，為了進行比較，在這項研究中也使用奈米級的Poly(HEMA)顆粒進行細胞培養。結果顯示，Poly(HEMA)的奈米顆粒對於L929細胞的黏附力太弱，因此顆粒無法黏附在細胞上。此研究成果顯示，將殼聚糖塗覆在所合成的Poly(HEMA)多孔微米顆粒，顯示了最佳結果，此結果顯示其在三維組織工程中，可作為良好的生物支架，擁有良好的前景。

Polymer beads have gained a lot of interest in tissue engineering due to the construction of three dimensional (3-D) porous scaffolds for implanting into a defect site. Polymer beads which are spherical particles offer high cell yields in small volumes due to high surface area to volume ratio of polymeric particles. In this research, preparations of poly(2-hydroxyethyl methacrylate) (poly(HEMA)) in microparticle and nanoparticle size were successfully synthesized via suspension and emulsion polymerization techniques. In microparticle, a positively charged monomer of 2-(diethylamino)ethyl methacrylate (DEAEMA) was randomly copolymerized with HEMA monomer to enhance the cell adhesion onto the particles. Moreover, chitosan was coated on poly(HEMA) microparticles to increase the biocompatibility of the particles. To promote the intermolecular forces onto cells, porous poly(HEMA) microparticles with average diameter of 400 µm were successfully synthesized. For comparison, the average diameter around 650 nm poly(HEMA) nanoparticles were also synthesized. Adding of DEAEMA monomer in poly(HEMA) microparticles enhanced the thermal stability of the synthesized particles. From the thermogravimetric analysis, the temperatures of 5% weight loss (T5%) for poly(HEMA) microparticles without and with DEAEMA were estimated as 204℃ and 275℃, respectively. The synthesized cationic charged monomer consisted in poly(HEMA) microparticles promoted the L929 cell adhesion clearly. Chitosan coated poly(HEMA) microparticles also increased the attached cell amounts of L929 significantly. The optimal cell adhesion was achieved on the poly(HEMA) microparticles with 0.02 mol DEAEMA and chitosan coating. In this study, cell culture using poly(HEMA) nanoparticles was also carried out. The results showed that poly(HEMA) nanoparticles adhesion on L929 cells was too weak to attach onto cells. From the results, the synthesized poly(HEMA) porous microparticles coated with chitosan showed a good future for 3-D tissue engineering application using as scaffolds.

1. Justice, B.A., Badr, N.A., and Felder, R.A., 3D cell culture opens new dimensions in cell-based assays. Drug discovery today, 2009. 14(1-2): p. 102-107.
2. Cer, E., Gurpinar, O.A., Onur, M.A., and Tuncel, A., Polyethylene glycol-based cationically charged hydrogel beads as a new microcarrier for cell culture. J Biomed Mater Res B Appl Biomater, 2007. 80(2): p. 406-14.
3. Chen, R., Curran, S.J., Curran, J.M., and Hunt, J.A., The use of poly (l-lactide) and RGD modified microspheres as cell carriers in a flow intermittency bioreactor for tissue engineering cartilage. Biomaterials, 2006. 27(25): p. 4453-4460.
4. Gumusderelioglu, M., Cakmak, S., Timucin, H.O., and Cakmak, A.S., Thermosensitive PHEMA microcarriers: ATRP synthesis, characterization, and usabilities in cell cultures. J Biomater Sci Polym Ed, 2013. 24(18): p. 2110-25.
5. Bukowska, A., Bukowski, W., and Noworól, J., New 2-hydroxyethyl methacrylate resins with good swelling characteristics. Journal of Applied Polymer Science, 2006. 101(3): p. 1487-1493.
6. Peppas, N.A. and Korsmeyer, R.W., Dynamically swelling hydrogels in controlled release applications. Hydrogels in medicine and pharmacy, 1987. 3: p. 109-136.
7. Arica, M., Hasirci, V., and Alaeddinoǧlu, N., Covalent immobilization of α-amylase onto pHEMA microspheres: preparation and application to fixed bed reactor. Biomaterials, 1995. 16(10): p. 761-768.
8. Robert, C.C., Buri, P.A., and Peppas, N.A., Influence of the drug solubility and dissolution medium on the release from poly (2-hydroxyethylmethacrylate) microspheres. Journal of controlled release, 1987. 5(2): p. 151-157.
9. Hutcheon, G., Messiou, C., Wyre, R., Davies, M., and Downes, S., Water absorption and surface properties of novel poly (ethylmethacrylate) polymer systems for use in bone and cartilage repair. Biomaterials, 2001. 22(7): p. 667-676.
10. Hattori, S., Andrade, J., Hibbs Jr, J., Gregonis, D., and King, R., Fibroblast cell proliferation on charged hydroxyethyl methacrylate copolymers. Journal of Colloid and Interface Science, 1985. 104(1): p. 72-78.
11. Islam, M.M., Shahruzzaman, M., Biswas, S., Nurus Sakib, M., and Rashid, T.U., Chitosan based bioactive materials in tissue engineering applications-A review. Bioact Mater, 2020. 5(1): p. 164-183.
12. Callister Jr, W.D. and Rethwisch, D.G., Fundamentals of materials science and engineering: an integrated approach. 2012: John Wiley & Sons.
13. Carraher Jr, C.E., Seymour/Carraher's polymer chemistry. Vol. 16. 2003: CRC press.
14. Odian, G., Principles of polymerization. 2004: John Wiley & Sons.
15. Chern, C., Emulsion polymerization mechanisms and kinetics. Progress in polymer science, 2006. 31(5): p. 443-486.
16. El-hoshoudy, A.N.M.B., Emulsion Polymerization Mechanism. Recent Research in Polymerization, 2018: p. 1.
17. Ma, P.X., Scaffolds for tissue fabrication. Materials today, 2004. 7(5): p. 30-40.
18. Viola, J., Lal, B., and Grad, O., The emergence of tissue engineering as a research field. National Science Foundation, Arlington, VA, 2003: p. 2-11.
19. Leong, K.F., Chua, C.K., Sudarmadji, N., and Yeong, W.Y., Engineering functionally graded tissue engineering scaffolds. Journal of the Mechanical Behavior of Biomedical Materials, 2008. 1(2): p. 140-152.
20. Turnbull, G., Clarke, J., Picard, F., Riches, P., Jia, L., Han, F., Li, B., and Shu, W., 3D bioactive composite scaffolds for bone tissue engineering. Bioactive materials, 2018. 3(3): p. 278-314.
21. Puppi, D., Chiellini, F., Piras, A., and Chiellini, E., Polymeric materials for bone and cartilage repair. Progress in Polymer Science, 2010. 35(4): p. 403-440.
22. Gabler, F., Frauenschuh, S., Ringe, J., Brochhausen, C., Götz, P., Kirkpatrick, C.J., Sittinger, M., Schubert, H., and Zehbe, R., Emulsion-based synthesis of PLGA-microspheres for the in vitro expansion of porcine chondrocytes. Biomolecular engineering, 2007. 24(5): p. 515-520.
23. Workman, V.L., Tezera, L.B., Elkington, P.T., and Jayasinghe, S.N., Controlled Generation of Microspheres Incorporating Extracellular Matrix Fibrils for Three‐Dimensional Cell Culture. Advanced functional materials, 2014. 24(18): p. 2648-2657.
24. Fang, J., Zhang, Y., Yan, S., Liu, Z., He, S., Cui, L., and Yin, J., Poly (L-glutamic acid)/chitosan polyelectrolyte complex porous microspheres as cell microcarriers for cartilage regeneration. Acta biomaterialia, 2014. 10(1): p. 276-288.
25. Caló, E. and Khutoryanskiy, V.V., Biomedical applications of hydrogels: A review of patents and commercial products. European Polymer Journal, 2015. 65: p. 252-267.
26. Cook, A.D., Sagers, R.D., and Pitt, W.G., Bacterial adhesion to poly (HEMA)‐based hydrogels. Journal of biomedical materials research, 1993. 27(1): p. 119-126.
27. Bayramoğlu, G., Yalçin, E., and Arıca, M.Y., Immobilization of urease via adsorption onto l-histidine–Ni(II) complexed poly(HEMA-MAH) microspheres: Preparation and characterization. Process Biochemistry, 2005. 40(11): p. 3505-3513.
28. Cer, E., Gürpınar, Ö.A., Onur, M.A., and Tuncel, A., Polyethylene glycol‐based cationically charged hydrogel beads as a new microcarrier for cell culture. Journal of Biomedical Materials Research Part B: Applied Biomaterials: An Official Journal of The Society for Biomaterials, The Japanese Society for Biomaterials, and The Australian Society for Biomaterials and the Korean Society for Biomaterials, 2007. 80(2): p. 406-414.
29. Lao, L., Tan, H., Wang, Y., and Gao, C., Chitosan modified poly (L-lactide) microspheres as cell microcarriers for cartilage tissue engineering. Colloids and Surfaces B: Biointerfaces, 2008. 66(2): p. 218-225.
30. Xu, X., Goponenko, A.V., and Asher, S.A., Polymerized PolyHEMA Photonic Crystals:  pH and Ethanol Sensor Materials. Journal of the American Chemical Society, 2008. 130(10): p. 3113-3119.
31. Mendizabal, E., Castellanos-Ortega, J., and Puig, J., A method for selecting a polyvinyl alcohol as stabilizer in suspension polymerization. Colloids and surfaces, 1992. 63(3-4): p. 209-217.
32. Kiremitçi, M. and Çukurova, H., Production of highly crosslinked hydrophilic polymer beads: effect of polymerization conditions on particle size and size distribution. Polymer, 1992. 33(15): p. 3257-3261.
33. Lim, A.R., Schueneman, G., and Novak, B., The T1ρ 13C spin-lattice relaxation time of interpenetrating networks by solid state NMR. Solid state communications, 1999. 109(7): p. 465-470.
34. Samsonova, O., Pfeiffer, C., Hellmund, M., Merkel, O.M., and Kissel, T., Low molecular weight pDMAEMA-block-pHEMA block-copolymers synthesized via RAFT-polymerization: potential non-viral gene delivery agents? Polymers, 2011. 3(2): p. 693-718.
35. Demirelli, K., Coşkun, M., and Kaya, E., A detailed study of thermal degradation of poly (2-hydroxyethyl methacrylate). Polymer degradation and stability, 2001. 72(1): p. 75-80.
36. Ayhan, H., Gurhan, I., and Piskin, E., Attachment of 3T3 and MDBK cells onto poly(EGDMA/HEMA) based microbeads and their biologically modified forms. Artif Cells Blood Substit Immobil Biotechnol, 2000. 28(2): p. 155-71.
37. YU, B. and ZHAO, Y., CO 2-Modulated Self-Assembly of Block Copolymers. World Scientific Reference of Hybrid Materials, 2019. 17: p. 209.
38. Sekerak, N.M., Hutchins, K.M., Luo, B., Kang, J.G., Braun, P.V., Chen, Q., and Moore, J.S., Size control of cross-linked carboxy-functionalized polystyrene particles: Four orders of magnitude of dimensional versatility. European Polymer Journal, 2018. 101: p. 202-210.
39. Sencadas, V., Correia, D.M., Ribeiro, C., Moreira, S., Botelho, G., Gómez Ribelles, J.L., and Lanceros-Mendez, S., Physical-chemical properties of cross-linked chitosan electrospun fiber mats. Polymer Testing, 2012. 31(8): p. 1062-1069.
40. Singh, P., Medronho, B., Alves, L., da Silva, G., Miguel, M., and Lindman, B., Development of carboxymethyl cellulose-chitosan hybrid micro-and macroparticles for encapsulation of probiotic bacteria. Carbohydrate polymers, 2017. 175: p. 87-95.
41. Vargün, E. and Usanmaz, A., Degradation of poly (2-hydroxyethyl methacrylate) obtained by radiation in aqueous solution. Journal of Macromolecular Science, Part A: Pure and Applied Chemistry, 2010. 47(9): p. 882-891.
42. Xi, J., Chen, J., Garcia, M., and Penn, L., Quartz crystal microbalance in cell biology studies. J Biochips Tissue Chips S, 2013. 5: p. 1-9.
43. Kumar, M.N.R., A review of chitin and chitosan applications. Reactive and functional polymers, 2000. 46(1): p. 1-27.
44. Kim, I.-Y., Seo, S.-J., Moon, H.-S., Yoo, M.-K., Park, I.-Y., Kim, B.-C., and Cho, C.-S., Chitosan and its derivatives for tissue engineering applications. Biotechnology advances, 2008. 26(1): p. 1-21.
45. Parish, C.R., Fluorescent dyes for lymphocyte migration and proliferation studies. Immunology and cell biology, 1999. 77(6): p. 499-508.
46. Kapałczyńska, M., Kolenda, T., Przybyła, W., Zajączkowska, M., Teresiak, A., Filas, V., Ibbs, M., Bliźniak, R., Łuczewski, Ł., and Lamperska, K., 2D and 3D cell cultures–a comparison of different types of cancer cell cultures. Archives of medical science: AMS, 2018. 14(4): p. 910.
47. Lydon, M., Minett, T., and Tighe, B., Cellular interactions with synthetic polymer surfaces in culture. Biomaterials, 1985. 6(6): p. 396-402.
48. Roointan, A., Farzanfar, J., Mohammadi-Samani, S., Behzad-Behbahani, A., and Farjadian, F., Smart pH responsive drug delivery system based on poly (HEMA-co-DMAEMA) nanohydrogel. International journal of pharmaceutics, 2018. 552(1-2): p. 301-311.
49. Takeuchi, I., Ariyama, M., and Makino, K., Chitosan Coating Effect on Cellular Uptake of PLGA Nanoparticles for Boron Neutron Capture Therapy. Journal of oleo science, 2019: p. ess18239.