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Copper ions (Cu) grafted chitosan coating was prepared using the pneumatic spraying method on the silicone rubber surface. Coating's surface properties, morphology, composition, Cu releasing behavior, antibacterial, and anti‐inflammatory activities are investigated and discussed. Surface properties, composition, and morphology were investigated by scanning electron microscopy (SEM) and contact angle measurements. The antibacterial activity has been tested with Escherichia coli and Staphylococcus aureus suspensions in vitro. Besides, the morphology of the biofilm was inspected with a field emission SEM. To evaluate the anti‐inflammatory activity and biosafety of the coating in vivo, the optimized coating samples and control groups were implanted subcutaneously into the back of mice. The bacterial environment model was established by injection of the bacterial suspension. The morphology and bacterial adhered on the surface of catheters and the surrounding tissues were analyzed after 5 days of implantation. As in vitro results, the number of adhered bacterial on the surface of the silicon rubber surface was decreased, and the anti‐inflammatory rate was increased by the intensify of the Cu content in chitosan coating. As for in vivo results, after 5 days of implantation, there was no evident inflammation in the surrounding tissues of all catheters in all without the S. aureus injected group. In the injected chitosan/Cu coated group; the inflammation, the number of the adhered bacteria were observed less than other injected samples without Cu; no inflammation were noticeable. Results indicate that the Cu‐modified chitosan coating can confer excellent antibacterial and anti‐inflammatory activity as applied on medical catheters.

Retinoblastoma is the most common intraocular cancer with metastatic potential affecting infants and children. Although chemotherapy is available for retinoblastoma, side effects and drug resistance are frequent. Rpl41, encoding ribosomal protein L41 (RPL41), has been identified as a tumor suppressor gene, and its targeted degradation of activating transcription factor 4 (ATF4) produces an antitumor effect. The goal of the present study is to provide experimental evidence for the clinical application of a small peptide regimen in combination with chemotherapy for the treatment of retinoblastoma and to investigate the mechanism of their combined cytotoxicity. It was observed that treatment with the RPL41 peptide alone decreased the viability, migration, and invasion of retinoblastoma Y79 and Weri-Rb1 cells, in addition to promoting cell apoptosis and cell cycle arrest. Furthermore, RPL41 protein levels showed a significantly decreased trend in retinoblastoma specimens, whereas ATF4 protein levels tended to be increased. Mechanistically, ATF4 degradation as a result of RPL41 peptide treatment was observed in retinoblastoma Y79 and Weri-Rb1 cells. Most important, low-dose administration of the RPL41 peptide significantly enhanced the antitumor effect of carboplatin, and further analysis confirmed their synergistic effect as anti-retinoblastoma therapy, indicating that RPL41 sensitized Y79 and Weri-Rb1 retinoblastoma cells to carboplatin. Thus, our data provide a preclinical rationale for the exploration of the RPL41 peptide as a potential adjuvant to carboplatin treatment in retinoblastoma.

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