The Characterization of chitosan-hyaluronan-metal nanocomposites
Yang-Chia Shih
1, a, Hui-Hsuan Hsieh
2,b, Tzong-Ming Wu
2,cand Chih-Wei
Chou*
3,d1 Department of Biotechnology, Asia University, Taichung, Taiwan
2 Department of Materials Science and Engineering, National Chung Hsing University, Taichung,
Taiwan
3 Department of Cosmeceutic, China Medical University, Taichung, Taiwan, R.O.C. a[email protected], b[email protected], c [email protected], d
Keywords: chitosan, Hyaluronan, nanocomposites
Abstract. Chitosan and hyaluronan were used as biocompatible materials for biomedical
application. In here, we prepared the Hyaluronan (HA) coated metal nanostructures. The chitosan (CS) films containing various concentrations of HA-coated Au or HA-coated Ag@Au nanostructures. We demonstrated that HA-coated spherical-like gold (HA-AuS), HA-coated wire-like gold (HA-AuW) or HA-coated Ag@Au could be dispersed in chitosan matrix by mixing and in aqueous solution casting. The introduction of HA-AuS, HA AuW and HA-Ag@Au nanostructures could not only improve the physical properties of CS, but also enhance the biocompatibility.
Introduction
In recent years, the structure and properties of composite thin films consisting of nanosized metal particles dispersed in polymeric matrices has been the subject of intense research both for fundamental reasons and for practical applications [1,2]. The physical and chemical properties of such composite films are usually dependent on film microstructure. To obtain a composite film with the desired properties, it is necessary to manipulate the microstructure of the film, i.e., size and concentration of the dispersed metal particles, and the spatial distribution of the particles in the composite film. There are a wide variety of fabrication methods for polymer films containing small metal particles [3,4], including physical and chemical processes such as casting of polymer solutions, inclusion of metal particles and plasma polymerization of organic monomers with simultaneous or alternating metal evaporation or sputtering.
In this study, we synthesized the biocompatible chitosan (CS)-Hyaluronan (HA)-coated metal nanocomposites. The CS films containing various concentrations of HA-coated Au or HA-coated Ag@Au nanostructures were characterized by UV-Vis-NIR spectrophotometer, field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM).
All glassware used in the following procedures was cleaned of freshly prepared 3:1 v/v HCl: HNO3 (aqua regia) and rinsed thoroughly in Milli-Q grade water prior to use. The synthesis of gold seeds was adapted according to the Frens method [5]. A 100 mL of an aqueous solution of 1 × 10-4 M HAuCl4 was heated to boiling. Next, 10 mL of an aqueous solution of 1% sodium citrate was added to HAuCl4 solution and boiling was continued. The color of the solution first turned purple and on further boiling changed to ruby red, indicating the formation of gold seeds. The size of seeds in this study about was 15 ± 3 nm.
The different concentration of HA/seeds mixture solutions were prepared by mixing the HA powder into seeds solutions under strong stirring. Next, an aqueous solution HAuCl4 or AgNO3 was added to the HA/seeds mixed solution. After heating reaction, HA-coated Au or HA-coated Ag@Au nanostructures were synthesized. Then, the nanostructures were added to the chitosan solution to synthesize chitosan (CS)-Hyaluronan (HA)-coated metal nanocomposites.
Results
Fig. 1 showed UV-Vis-NIR spectra of HA-metal NSs, we can find HA-AuS and HA-AuW appear 538 and 559 nm, respectively. The HA-Ag@Au peak at 435 nm corresponds to the characteristic surface plasmon resonance of silver nanoparticles. Fig. 2 revealed SEM and TEM images of HA-metal particles. The average particle size of HA-AuS (Fig.2 A) is estimated to be 37 nm with spherical structure from the TEM micrographs. Fig.2 B showed the structures are wire-like in shape. The EDS analysis (Fig. 3) giving an evidence of the gold or silver presence. The carbon, nitro and oxygen identified the element of hyaluronic acid. Fig. 4 are SEM imagse of pure CS film and CS-HA-metal film. The pure chitosan film was more smooth, and the chitosan-HA-metal film were became rough, may is the addition of HA-metal NSs make the crystalline structure change. The water contact angle results of pure CS film and CS-HA-metal film are showed in Fig. 5. The angle of chitosan-HA-metal film are lower angle than pure chitosan film might because the content of HA.
Fig.2. SEM and TEM micrographs of HA-metal nanocomposites. (A)HA-AuS (B)HA-AuW (C) HA-Ag@Au.
Fig.3 EDS analysis of HA-metal nanocomposites. (A)HA-AuS (B)HA-Ag@Au.
Fig.4. SEM micrographs of (A) pure CS film and CS-HA-metal film: (B)HA-AuS (C)HA-AuW (D) HA-Ag@Au.
Fig.5. Water contact angle of (A) pure CS film and CS-HA-metal film: (B)HA-AuS (C)HA-AuW (D) HA-Ag@Au.
Conclusion
This research successfully synthesized metal nanoparticles with high biocompatibility by greenmethod. We demonstrated that HA-coated spherical-like gold (HA-AuS), HA-coated wire-like gold (HA-AuW) or HA-coated Ag@Au could be dispersed in chitosan matrix by mixing and in aqueous solution casting. Further research is required to characterize this chitosan-hyaluronan-metal nanocomposites for variety application.
References
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