Antibiofilm and Anticancer Activity of Multi-Walled Carbon Nanotubes Fabricated with Hot-Melt Extruded Astaxanthin-Mediated Synthesized Silver Nanoparticles.

Purpose: Multi-walled carbon nanotubes (MWCNTs) were used as carriers for silver nanoparticles (AgNPs). In this process, MWCNTs were coated with mesoporous silica (MWCNT-Silica) for uniform and regular loading of AgNPs on the MWCNTs. In addition, astaxanthin (AST) extract was used as a reducing agent for silver ions to enhance the antioxidant, antibiofilm, and anticancer activities of AgNPs. In this process, AST was extracted from and processed by hot melt extrusion (HME) to enhance the AST content of . AST has strong antioxidative properties, which leads to anticancer activity. In addition, AgNPs are well known for their strong antibacterial properties. The antibiofilm and anticancer effects were studied comprehensively by loading the AST AgNPs onto MWCNT-Silica.

Methods: AgNPs-loaded MWCNT-silica (MWCNT-Ag) was prepared through the binding reaction of TSD and silanol groups and the aggregation interaction of Ag and TSD. To enhance the antioxidant, antibiofilm, and anticancer activities of AgNPs, HME-treated extract (HME-AST) was used as a reducing solution of silver ions. The increased AST content of HME-AST was confirmed by high-performance liquid chromatography (HPLC) analysis, and the total phenol and flavonoid content analysis confirmed that HME enhanced the active components of . The antibiofilm activity of MWCNT-AST was investigated by biofilm inhibition and destruction test, SEM, and CLSM analysis, and the anticancer activity was investigated by WST assay, fluorescent staining analysis, and flow cytometry analysis.

Results: MWCNT-AST showed higher antioxidant activity and antibiofilm activity than MWCNT-Ag against , and methicillin-resistant (MRSA). MWCNT-AST showed higher anticancer activity against breast cancer cells (MDA-MB-231) than MWCNT-Ag, and lower toxicity in normal cells HaCaT and NIH3T3.

Conclusion: MWCNT-AST exhibits higher antioxidant, antibiofilm, and anticancer activities than MWCNT-Ag, and exhibits lower toxicity to normal cells.