Extraction of poultry feather keratin and its application as drug delivery systems for precise tumor chemotherapy

Glutathione (GSH)-triggered drug delivery systems (DDSs) have been well-recognized as a powerful approach for tumor-selective chemotherapy with minimized toxic side effects. As cysteine-containing derivatives of natural protein, the kerateines, which are obtained via the reduction of poultry feather keratin, possess plentiful thoil groups, making them promising candidate in the disulfide-containing DDS for GSH-triggered tumor-specific drug delivery, via non-covalent drug-loading or covalent conjugating drug onto the kerateines as prodrugs with disulfide linker as bioreducible dynamic covalent bond. Here, the extraction of poultry feather keratin and its application as drug delivery systems for precise tumor chemotherapy are reviewed. And the future perspective is also proposed.