Specific pathogen free rats

Healthy male, specific pathogen free rats aged 7 weeks and weighing ~300 g were provided by the Beijing Vital River Laboratory Animal Technology Co., Ltd. (Beijing, China). Animal use was in line with the guidelines of the National Institutes of Health (NIH) for animal studies (Principles for Feeding and Using Laboratory Animals) and approved by the Animal Ethics Committee of Jilin University (Approval No.: AEC-2017-01, Approval Date: 12 January 2017).
Ozonization was performed for 2 h before scaffold implantation, followed by ventilation in a super clean bench for 12 h. The rats were randomly assigned to four groups (n = 12/group): blank (Control) group; PLGA/HA scaffold (Scaffold) group; PLGA/HA+collagen (Scaffold+Col) group; and PLGA/HA+collagen+DGEA (Scaffold+Col+DGEA) group. All rats were sacrificed by anesthesia at 6 or 12 weeks after implantation.

Sixteen specific pathogen-free rats aged 6–8 weeks, with body weights of approximately 220–280 g, were purchased from Vital River Laboratory Animal Technology (Beijing, China). Among the rats, 8 were salt-sensitive (Dahl-ss), and 8 were salt-insensitive (SS-13BN). High-salt (8% sodium chloride) and low-salt (0.25% sodium chloride) diets were administered to the salt-sensitive (SS) and salt-insensitive (SI) groups, with four rats within each group assigned randomly to the high- and low-salt subgroups, respectively (Figure 1(a)). This research was performed according to the National Institutes of Health guide for the care and use of Laboratory Animals (NIH Publications No. 8023, revised 1978), and the animals used in the experiment are males. The study was approved by the Animal Welfare and Ethics Group of the Department of Laboratory Animal Science, Fudan University (201811001Z).