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Silk is a fibrous biopolymer with a recorded history in the textile industries for centuries. This fibre is constituted of two different proteins: fibroin and sericin, of which the latter accounting for approximately 20–30 % of the silk mass. Silk sericin (SSER) was previously considered as a waste by-product in silk fibroin extraction. SSER has recently garnered significant scientific interest due to its extensive biological and pharmacological properties. These include antioxidant effects, biocompatibility, low immunogenicity, controlled biodegradability, and the ability to induce cell proliferation. This review covers studies about various aspects of this emerging material, namely, its general morphology, specific structure, molecular weight, features of different layers, and gene sequences. The impact of different extraction methods and the application of extracted SSER based on molecular weight are discussed. Additionally, the characteristic functional groups in the amino acids of sericin facilitate its applications in regenerative medicine, wound healing, drug delivery, textile, environment, and energy, in various forms like hydrogels, films, scaffolds, and conduits. SSER-based materials offer great potentials for multi-functional applications in the upcoming decades, showcasing adaptability for various functional uses and promising future technological advancements.

Synthetic 4-Chloroethcathinone (4-CEC) is a derivative of cathinone that belongs to one of the more severe abused substances among new psychoactive substances (NPS). Current researches on 4-CEC mainly focus on metabolite identification studies, and there is a lack of researches on pharmacokinetic, tissue distribution and metabolomics studies in vivo. A sensitive and reliable LC-MS/MS assay was developed and validated for the determination of 4-CEC concentrations in plasma and tissue homogenates. According to the pharmacokinetic results, the absorption and elimination of 4-CEC were faster after administration. The Cmax was 1896 ± 876 ng/ml, the peak time Tmax was 10.1 ± 9.2 min, and the elimination half-life t1/2 was 100.4 min. Metabolomics studies showed that the highest concentrations of 4-CEC were found in brain, lung, kidney and liver. The results of tissue biopsy showed that the liver, kidney and brain tissue had a certain degree of damage. After 4-CEC administration, amino acid-related metabolism and biosynthesis, lipid metabolism, niacin and niacinamide metabolism in mice were interfered, suggesting that 4-CEC could cause energy metabolism disorder in mice. The metabolic pathways and toxicity mechanisms related to 4-CEC entry into the body were explained at the overall metabolic level by multivariate data analysis, screening and identification of differential metabolites and metabolic pathway analysis.