| Recently, alternative wound dressing methods, which can maintain an optimal environment to accelerate the wound healing process, have been attracted by many studies. Natural biomaterials and synthetic materials have been employed to fabricate functional dressings for wound care. Among them, chitosan (CS) has been considered as a favorable material due to its biocompatibility, non-toxicity, biodegradability, intrinsic antibacterial properties, etc. Because of these good biological properties, the CS becomes one of the materials of for wound dressing. Chitosan wound dressings are a variety of forms. Chitosan fibers (CS-Fs) are the most popular form arising from its adequate drainage of exudates and adherence to wound bed to avoid dead space. Nevertheless, low liquor absorptivity and binding capacity of traditional CS-Fs are limited to create a moist environment around the wound surface. In addition, the CS-Fs tend to integrate into the wound during the healing process and lead to second injuries. Aiming to the existing defects of chitosan fiber, we need to modify CS-Fs to prepare of high fluid absorption CS-Fs wound dressings.In this paper, the chitosan fibers with surface N-succinylation (N-succinyl chitosan fibers, NSCS-Fs) were developed with the chitosan fibers and hydrophilic groups, which were exploited and conjugated to the amino groups of CS chains to strengthen the liquor absorption of CS fibrous. The purpose of this experiment is to resolve the problems of the low liquor absorptivity and binding capacity of CS-Fs. The physicochemical property, biosecurity, and biocompatibility of NSCS-Fs were done to evaluate the eligibility of NSCS-Fs for wound healing applications. According to FTIR spectrum and solid-state UC NMR analysis, it suggested that the amino groups of CS-Fs were substituted and the succinylation took place at the N-position. The DS of NSCS-Fs was determined to be 21.77% according to the element analysis.The MW of the NSCS-Fs obtained by GPC was 9.79×105 g/mol. The SEM (sanning electron microscope) showed that the surface of the modified NSCS-Fs is t smooth and displays various cracks. The morphological changes after lification were probably attributed to reduce the tenacity. Liquor absorbing capacity study showed the absorptivity of NSCS-Fs increased more rapidly, and the maximum liquor absorbing ratio of NSCS-Fs was 1400%, about 1.7 folds greater (?)hose of CS-Fs. Afterwards, a mass loss of NSCS-Fs during the above process (?)served. The biosecurity and biocompatibility of NSCS-Fs were done in vitro an in vivo. Cytotoxicity assay showed the cell viability of NSCS-Fs was higher than 100%at either concentration, demonstrating that NSCS-Fs were non-toxic in vitro. The i nhibition ratios of NSCS-Fs against E. coli and S. aureus were higher than 90%. The nhibition ratio of NSCS-Fs was higher than that of CS-Fs and CS, which proved ths the NSCS-Fs were more effective in inhibiting bacterial growth. In dermal in. ion test and delayed type hypersensitivity of NSCS-Fs’leach liquor, no erythema and dropsy were observed on the surface of any test points and the skin was in normal (?) These results indicated that NSCS-Fs were not irritating to skin and caused the (?)nflammatory response. In the acute oral toxicity test, no mouse showed toxic (?)toms and weight increase was observed for either group instead of weight loss a month administrated with NSCS-Fs* leach liquor. For the muscle implantation in (?), NSCS-Fs degraded into some small fragments after the 2 week. The number of inflammatory cells gradually decreased and the inflammatory response was weaker compared with the control groups. In addition, the macrophages packed the broken (?)ber fragments that indicated NSCS-Fs are more biocompatible material to be (?)wound dressings.According to the experiments, the results of physicochemical property, biosecurity, biocompatibility and many other features of NSCS-Fs indicated the NSCS-Fs were promising material for wound care. |
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