Paraformaldehyde (pfa)

The modified resin synthesis formula is as follows. The molar ratio of phenol to aldehyde is 1:1.4, while the amount of 3-pentadecyl-phenol is approximately 5%–25% (the step was 2%) of the total amount of phenol. The amount of the basic catalyst was 1% of the total amount of the phenol.
The synthetic route for phenolic resin modified by 3-pentadecyl-phenol is shown in Scheme 1, while the detailed synthetic methods are described below.
We first added phenol and 3-pentadecyl-phenol to the three-necked flask (Tianjin Damao Chemical Reagent Factory, Tianjin, China) which was stirred using a paddle according to the ratio (the temperature of the water bath is about 60–65 °C). After this, we added a certain amount of sodium hydroxide as the catalyst and stirred it evenly for about 5 min, which allowed for the activation of phenol and modifiers. After we added the paraformaldehyde into the flask (Tianjin Damao Chemical Reagent Factory, Tianjin, China) in three batches within half an hour, we maintained the temperature of the water bath for 30–40 min and let the paraformaldehyde react fully. After this, we raised the temperature of the water bath to 85–90 °C and allowed the mixture to react continuously for about 90 min to obtain the modified phenolic resin.

SM was obtained from Shanxi Taihang Pharmaceutical Co., Ltd. (Shanxi, China). Atorvastatin calcium salt trihydrate was supplied by Tokyo Chemical Industry Co., Ltd. (Tokyo, Japan). 12 hydration disodium hydrogen phosphate, potassium chloride, sodium chloride, potassium dihydrogen phosphate, and sodium dihydrogen phosphate were all purchased from Tianjin Zhiyuan Chemical Reagent Co., Ltd. (Tianjin China). The liver tissues of each mice were fixed in 4% paraformaldehyde at 4°C for 24 h, then the fixed tissues were embedded in paraffin and cut into 3-μm sections with a microtome (Leica, Nussloch, Germany). paraformaldehyde (analytical grade) was supplied by Damao Chemical Reagent Factory (Tianjin). Hematoxylin–eosin (H&E) and neutral gum were purchased from Beijing Legend Biotech Co., Ltd. (Beijing, China) and Shanghai Yiyang Instrument Co., Ltd. (Shanghai, China), respectively. Triglyceride, total cholesterol, glucose, LDL-C, and HDL-C were measured by commercially available kits obtained from Shanghai Rongsheng Biotech Co., Ltd., while insulin was detected using kits supplied by Wuhan Huamei Biological Engineering Co. Ltd. (Wuhan, China).