Biosafety evaluation of chitosan lactate/hyaluronate sponge / 中国组织工程研究

ABSTRACT

BACKGROUND: Functional dressings have been widely used in clinical practice, but so far none of existing dressings can meet the clinical needs in terms of gas permeability, biocompatibility, comfort, and degradability. OBJECTIVE: To systemically evaluate the biosafety properties of water-soluble chitosan lactate/hyaluronan sponge after modification. METHODS: In the study, there were 10 male BALB/C mice of SPF grade (6-8 weeks old), 20 Sprague-Dawley rats of SPF grade (7 weeks old, both genders), and 3 male New Zealand white rabbits (8 weeks old), all provided by Dongguan Songshanhu Pearl Animal Technology Co., Ltd. The chitosan lactate/hyaluronan sponge was prepared for cytotoxicity test. A blank control group was set. According to the GB/T16886 biological evaluation system, the rabbits were subjected to composite sponge stimulation and sensitization and intradermal reaction tests from the perspective of biosafety, and then divided into non-polar extract group, polar extract group and negative control group. The inoculation site was observed within 72 hours. The mice were subjected to acute toxicity test, and divided into experimental group (extraction solution) and control group (pure saline), and their manifestations were observed for 72 hours. The rats were subjected to subchronic toxicity test, and then divided into experimental group (subcutaneous implantation of composite sponge) and control group (making a skin incision on the back followed by suturing). The changes in body weight of the rats were observed, blood samples from the rats were taken intravenously for blood routine analysis at 13 weeks after testing, and the rats were anesthetized and executed in the next day for gross observations of the heart, liver, spleen, kidney, brain, pancreas, thymus, stomach, and bladder. RESULTS AND CONCLUSION: (1) The chemical structure of the modified composite sponge formed as expected. The cytotoxicity of the composite sponge was grade 1, which was not significantly different from the negative control group. (2) The skin irritation test showed no skin erythema and edema in the New Zealand white rabbits after being stimulated by the composite sponge, and the existing stimulation reactions were extremely mild. Almost no obvious sensitization reaction occurred. (3) No erythema and edema were captured in the intradermal reaction test, and intradermal reaction stimulation of the composite sponge was very weak. (4) In the acute toxicity test, no obvious toxicity symptoms such as hypocinesis, dyspnea and abdominal stimulation were observed in the mice. Furthermore, at the observational time point of 72 hours, no acute systemic toxicity occurred in the two groups. (5) In the subchronic toxicity test, no obvious difference was detected in the rat body mass between the experimental and control groups. The same conclusion was made in the hematology and organ coefficient tests. To conclude, the chitosan lactate/hyaluronate sponge has excellent biological properties and good biosafety, which can be applied for further clinical use.