Self-assembling peptides, offering favorable biocompatibility, high stability, and easy incorporation of various functionalities, have demonstrated enormous potential for the precise design of next-generation nanodrugs for non-invasive tumor therapy. Peptide-based supramolecular photodynamic therapy (PDT) has shown great promise as an emerging modality for cancer treatment, achieving substantially-enhanced photosensitizer delivery selectivity and treatment efficacy, based on peptide biological activity and self-assembly potential. Although considerable research has been conducted toward fabricating self-assembling peptide-based smart nanodrugs for PDT, few studies have investigated cellular biophysical responses as indicators of tumor function and metabolic state. Here, via atomic force microscopy (AFM)-based morphological and mechanical measurements, including optical microscopy and scanning electron microscopy, we observed, for the first time, variation in membrane stiffness of human liver (HepG2) cancer cells treated with self-assembling peptides serving as a PDT nanodrug. This biophysical information will help to establish a comprehensive understanding of the anticancer effect of peptide-based smart nanodrugs, and highlight the exceptional ability of AFM in determining cell-surface properties.
Polyurethane with zwitterionic side chains (PCB-ester-PU) based on a poly(carboxybetaine) ester analogue is developed for marine coatings and biomedical applications by introducing dihydroxy-terminated PCB-ester(OH)2 with different polymerization as the macrodiol, 4,4′-diphenylmethane diisocyanate (MDI) as the diisocyanate, and 1,4-butanediol (1,4-BD) as the chain extender. Robust coatings are obtained and exhibit long-term excellent resistance to nonspecific protein adsorption, bacterial adhesion, and human umbilical vein endothelial cell (HUVEC) attachment after hydrolysis. Tests of adhesion on different substrates and film hardness indicate that the material possesses far more stable mechanic properties than hydrogel coatings. Moreover, such a resistance can be generated not only by alkaline solution, but also by a physiological buffer (such as phosphate-buffered saline (0.15 M pH 7.4 PBS)) or by steam in an autoclave. Ultimately, its excellent long-term nonfouling property, its healing capability through self-regeneration and superior mechanic properties (such as hardness and elasticity), and its good adhesiveness as a paint on both polar and nonpolar substrates make this material an ideal candidate as a coating for marine and medical devices.
危险品化学品经营许可证（带存储）