Preparation and performance of chitosan-gelatin sponge-like wound-healing dressing
- VernacularTitle:壳聚糖-明胶海绵状伤口敷料的制备及其性能特征
- Author:
Lanzhen HE
;
Yi LIU
;
Dan YANG
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2007;11(26):5252-5256
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND:Chitosan has good filming and viscosity, it contains free amido, and can coordinate and cross-link with gelatin, thus natural semi-interpentrating polymer network structure can be formed among molecules through hydrogen bonds.OBJECTIVE: To prepare sponge-like wound-healing dressing of good porosity, hydrophilia and air permeability by means of frozen chitosan-gelatin mixture induced phase separation.DESIGN: A comparative observation.SETTING: Laboratory of the College of Science, Guangdong Ocean University. MATERIALS: Chitosan was deacetylated by 97.55%, Mη=1.85×106; Gelatin (CP grade) was produced by Shanghai Chemical Dispensing Factory; Glacial acetic acid, NaOH, formaldehyde and glycerin were all CP grade. XL30-EDAX scanning electron microscope (Philips, Dutch); 3365-type universal material testing machine. METHODS: ① By means of frozen chitosan-gelatin mixture induced phase separation chitosan solution of 0.2, 0.4, 0.5, 0.6 and 0.8 (mass fraction) was mixed with gelatin solution, then a small amount of glycerin to prepare sponge-like wound-healing dressing of good porosity, hydrophilia and air permeability. then a small amount of glycerin, and stayed quietly to deaerate. The samples were plated with gold as routine methods, and then the surface and sectional structures were observed under the scanning electron microscope. The effects of different proportion of chitosan and gelatin on the performance parameters (water retention, moisture absorption, avulsion intensity, air permeability rate) of the sponge-like materials were observed. ② Chitosan-gelatin mixtures of 18, 20, 22, 25, 24, 26 and 28 g/L (mass fraction) were used to prepare sponge-like materials, and the effects of different contents on the performances of the materials were observed. ③ The effects of cross-linking agent (formaldehyde) of different dosages (0.002, 0.004, 0.006, 0.008, 0.010, 0.012 and 0.014 in volume fraction) on the avulsion intensity of the materials were observed.MAIN OUTCOME MEASURES: ① Surface and sectional structures of the sponge-like wound-healing dressing; ② Effects of different proportion of chitosan and gelatin on the performance parameters of the sponge-like materials; ③ Effects of different contents on the performances of the chitosan-gelatin sponge-like materials; ④ Effects of cross-linking agent of different dosages on the avulsion intensity of the materials.RESULTS: ① It could be clearly seen from the surface that the chitosan-gelatin sponge-like materials were porous structure, whereas seen from the section, the pores were honey-comb formation or three-dimensional lamellar structure accumulated by porous lamellars. ② When the content of chitosan was greater, the section looked like honey comb;Whereas as the content of chitosan decreased and gelatin content increased, the section tended to parallel lamellar structure, the water content and water retention of corresponding samples had an ascending trend, but the alvusion iintensity increased at first, and then decreased. The mass fraction of 0.5 was suitable for chitosan in the prepared solution by comprehensively analyzing the performance parameters. ③ The lower the total concentration of chitosan and gelatin, the higher the water content, the easier for the formation of bigger self-chips on the surface, the porosity of the prepared materials increased, hydrophilia and water retention ability were increased, but greater cracks formed on the material surface, and avulsion intensity was smaller. As the concentration became higher, the viscosity of the mixture became greater, the excessive viscosity was not good for mixing uniform, thus the material surface was not plain enough, and the porosity was smaller, the hydrophilia and water retention ability were relatively decreased, and the materials were harder. The total concentration should be 22-25 g/L. ④ Once the dosage of cross-linking agent was too low, very few cross-linking points generated, and the intensity was too low; Once the dosage of cross-linking agent was too high, too many cross-linking points generated, and the net space was reduced, then water content and water retention value were decreased; Whereas overdosage cross-linking agent could increase the fragility of the sponge-like materials, manifested as the decrease of avulsion intensity. When formaldehyde of 0.01 in volume fraction, the avulsion intensity was the maximal, thus the dosage of 0.01 in volume fraction was the most suitable.CONCLUSION: The main factors that affect the structures and performances of the sponge-like wound-healing dressing are the proportion of chitosan and gelatin in the mixture, total concentration of the prepared solution, amount of powder and dosage of cross-linkage agent, etc. The best matching iss chitosan of 0.05 (volume fraction)/gelatin of 0.05 (volume fraction), total mass concentration of 22-25 g/L, amount of chitosan-gelatin powder mixture is 1∶1, and the dosage of cross-linking agent is 0.01 (volume fraction).
