Optimization Studies of Cryogel Scaffolds Prepared Using Different Chitosan and Polyvinyl Alcohol Ratios

Abstract

Cryogels are scaffolds structured with interconnected porous matrices produced from frozen solutions of monomeric or polymeric initiators. These scaffolds are seen as unique candidates with desirable properties for the different biomedical fields including tissue engineering, wound dressing, and drug delivery systems. In this study, polyvinyl alcohol (PVA) and chitosan (CS) were used to fabricate PVA:CS composite cryogels. Cryogels prepared at different polymer ratios were evaluated in terms of chemical structure, morphology, porosity, and swelling ratio. The chemical structure of composite cryogels was determined using Fourier-transform infrared spectroscopy (FTIR). The interconnected pore morphology was observed using Scanning Electron Microscopy (SEM). Porosity and swelling ratio values were determined based on the weight change of the cryogels. In general, all samples exhibited a porous structure, and it was revealed that porosity and other properties differ according to the ratio of each polymer in the scaffolds.

Keywords

• chitosan
• polyvinyl alcohol
• scaffold
• cryogel
• tissue engineering

Farklı Kitosan ve Polivinil Alkol Oranları Kullanılarak Hazırlanan Kriyojel Doku İskelelerinin Optimizasyon Çalışmaları

Öz

Kriyojeller, monomerik veya polimerik başlatıcıların donmuş çözeltilerinden üretilen birbirine bağlı gözenekli matrislerle yapılandırılmış yapı iskeleleridir. Bu yapı iskeleleri, doku mühendisliği, yara örtü ve ilaç salım sistemleri dahil olmak üzere farklı biyomedikal alanlar için arzu edilen özelliklere sahip benzersiz adaylar olarak görülmektedir. Bu çalışmada, polivinil alkol (PVA) ve kitosan (CS) polimerleri kullanılarak PVA:CS kompozit kriyojelleri üretilmiştir. Farklı polimer oranlarında hazırlanan kriyojeller kimyasal yapı, morfoloji, gözeneklilik ve şişme oranı açısından değerlendirilmiştir. Kompozit kriyojellerin kimyasal yapısı Fourier dönüşümü kızılötesi spektroskopisi (FTIR) kullanılarak belirlenmiştir. Birbirine bağlı gözenek morfolojisi, Taramalı Elektron Mikroskobu (SEM) kullanılarak gözlemlenmiştir. Porozite ve şişme oranı değerleri, kriyojellerin ağırlık değişimi esas alınarak belirlenmiştir. Genel olarak tüm numuneler gözenekli bir yapı sergilemiş ve gözeneklilik dahil diğer özelliklerin doku iskelesi yapısındaki her bir polimerin oranına göre farklılık gösterdiği ortaya konmuştur.

Anahtar Kelimeler

• kitosan
• polivinil alkol
• doku iskelesi
• kriyojel
• doku mühendisliği

Kaynakça

1. Akgönüllü, S., Bakhshpour, M., İdil, N., Andaç, M., Yavuz, H., & Denizli, A. (2020). Versatile polymeric cryogels and their biomedical applications. Hacettepe Journal of Biology and Chemistry, 48(2), 99–118. https://doi.org/10.15671/HJBC.629355
2. Annabi, N., Nichol, J. W., Zhong, X., Ji, C., Koshy, S., Khademhosseini, A., & Dehghani, F. (2010). Controlling the Porosity and Microarchitecture of Hydrogels for Tissue Engineering. Tissue Engineering. Part B, Reviews, 16(4), 371. https://doi.org/10.1089/TEN.TEB.2009.0639
3. Bölgen, N., Demir, D., Yalçın, M. S., & Özdemir, S. (2020). Development of Hypericum perforatum oil incorporated antimicrobial and antioxidant chitosan cryogel as a wound dressing material. International Journal of Biological Macromolecules, 161, 1581–1590. https://doi.org/10.1016/j.ijbiomac.2020.08.056
4. Ceylan, S., Göktürk, D., Demir, D., Damla Özdemir, M., & Bölgen, N. (2017). Comparison of additive effects on the PVA/starch cryogels: Synthesis, characterization, cytotoxicity, and genotoxicity studies. International Journal of Polymeric Materials and Polymeric Biomaterials, 1–10.
5. Choudhury, M., Mohanty, S., & Nayak, S. (2015). Effect of different solvents in solvent casting of porous PLA scaffolds—In biomedical and tissue engineering applications. Journal of Biomaterials and Tissue Engineering, 5(1), 1–9.
6. Demir, D., Ceylan, S., Göktürk, D., & Bölgen, N. (2020). Extraction of pectin from albedo of lemon peels for preparation of tissue engineering scaffolds. Polymer Bulletin, 78, 2211–2226. https://doi.org/10.1007/s00289-020-03208-1
7. Demir, D., Öfkeli, F., Ceylan, S., & Bölgen, N. (2016). Extraction and Characterization of Chitin and Chitosan from Blue Crab and Synthesis of Chitosan Cryogel Scaffolds. Journal of the Turkish Chemical Society, Section A: Chemistry, 3(3). https://doi.org/10.18596/jotcsa.00634
8. El-Sherbiny, I. M., & Yacoub, M. H. (2013). Hydrogel scaffolds for tissue engineering: Progress and challenges. Global Cardiology Science & Practice, 2013(3), 316. https://doi.org/10.5339/GCSP.2013.38

9. Henderson, T. M. A., Ladewig, K., Haylock, D. N., McLean, K. M., & O’Connor, A. J. (2013). Cryogels for biomedical applications. Journal of Materials Chemistry B, 1(21), 2682–2695. https://doi.org/10.1039/C3TB20280A
10. Kanimozhi, K., Khaleel Basha, S., & Sugantha Kumari, V. (2016). Processing and characterization of chitosan/PVA and methylcellulose porous scaffolds for tissue engineering. Materials Science and Engineering: C, 61, 484–491. https://doi.org/10.1016/J.MSEC.2015.12.084
11. Kumar, A. (2016). Supermacroporous Cryogels Biomedical and Biotechnological Applications.
12. Loh, Q. L., & Choong, C. (2013). Three-Dimensional Scaffolds for Tissue Engineering Applications: Role of Porosity and Pore Size. Tissue Engineering. Part B, Reviews, 19(6), 485. https://doi.org/10.1089/TEN.TEB.2012.0437
13. Pavoni, J. M. F., dos Santos, N. Z., May, I. C., Pollo, L. D., & Tessaro, I. C. (2021). Impact of acid type and glutaraldehyde crosslinking in the physicochemical and mechanical properties and biodegradability of chitosan films. Polymer Bulletin, 78(2), 981–1000. https://doi.org/10.1007/S00289-020-03140-4/FIGURES/8
14. Razavi, M., Qiao, Y., & Thakor, A. S. (2019). Three-dimensional cryogels for biomedical applications. Journal of Biomedical Materials Research Part A, 107(12), 2736–2755. https://doi.org/10.1002/JBM.A.36777
15. Rogers, Z. J., & Bencherif, S. A. (2019). Cryogelation and Cryogels. Gels, 5(4), 46. https://doi.org/10.3390/GELS5040046
16. Savina, I. N., Zoughaib, M., & Yergeshov, A. A. (2021). Design and Assessment of Biodegradable Macroporous Cryogels as Advanced Tissue Engineering and Drug Carrying Materials. Gels 2021, Vol. 7, Page 79, 7(3), 79. https://doi.org/10.3390/GELS7030079
17. Sergeeva, A., Vikulina, A. S., & Volodkin, D. (2019). Porous Alginate Scaffolds Assembled Using Vaterite CaCO3 Crystals. Micromachines 2019, Vol. 10, Page 357, 10(6), 357. https://doi.org/10.3390/MI10060357
18. Sornkamnerd, S., Okajima, M. K., & Kaneko, T. (2017). Tough and Porous Hydrogels Prepared by Simple Lyophilization of LC Gels. ACS Omega, 2(8), 5304–5314. https://doi.org/10.1021/ACSOMEGA.7B00602/SUPPL_FILE/AO7B00602_LIVESLIDES.MP4
19. Tang, Y. F., Du, Y. M., Hu, X. W., Shi, X. W., & Kennedy, J. F. (2007). Rheological characterisation of a novel thermosensitive chitosan/poly(vinyl alcohol) blend hydrogel. Carbohydrate Polymers, 67(4), 491–499. https://doi.org/10.1016/J.CARBPOL.2006.06.015
20. Tripathi, A., Kathuria, N., & Kumar, A. (2009). Elastic and macroporous agarose-gelatin cryogels with isotropic and anisotropic porosity for tissue engineering. Journal of Biomedical Materials Research. Part A, 90(3), 680–694. https://doi.org/10.1002/JBM.A.32127