biostudies-literatureCai ZNational Natural Science Foundation of China4251-4257https://www.ebi.ac.uk/biostudies/studies/S-EPMC9049068biostudies-literatureUnknown10(8)Long-term administration of chemotherapeutic agents often leads to multiple drug resistance (MDR), which greatly impairs the treatment outcome. To overcome this problem, a biodegradable nanocarrier based on an acid-sensitive calcium phosphate/silica dioxide (CAP/SiO₂) composite was constructed for the codelivery of drug and siRNA. Anticancer drug doxorubicin (DOX) was encapsulated into the composite scaffold by interacting with the exposed Ca²⁺ of CAP/SiO₂ to achieve high drug loading (180 μg mg^-1). With further decoration of siRNA, the nanocarrier was applied to enhance the therapeutic efficacy by silencing MDR-relevant genes (P-gp) of DOX-resistance K562/ADR cancer cells. Benefiting from the intrinsic acid degradability of CAP/SiO₂, RSC advancespH-sensitive CAP/SiO₂ composite for efficient co-delivery of doxorubicin and siRNA to overcome multiple drug resistance.PMC90490682177507021475057Jiang LPHe ZZhang YCai ZChen YWu XfalsepH-sensitive CAP/SiO₂ composite for efficient co-delivery of doxorubicin and siRNA to overcome multiple drug resistance.Long-term administration of chemotherapeutic agents often leads to multiple drug resistance (MDR), which greatly impairs the treatment outcome. To overcome this problem, a biodegradable nanocarrier based on an acid-sensitive calcium phosphate/silica dioxide (CAP/SiO₂) composite was constructed for the codelivery of drug and siRNA. Anticancer drug doxorubicin (DOX) was encapsulated into the composite scaffold by interacting with the exposed Ca²⁺ of CAP/SiO₂ to achieve high drug loading (180 μg mg^-1). With further decoration of siRNA, the nanocarrier was applied to enhance the therapeutic efficacy by silencing MDR-relevant genes (P-gp) of DOX-resistance K562/ADR cancer cells. Benefiting from the intrinsic acid degradability of CAP/SiO₂, 2020-01-01T00:00:00Z2020 Jan2025-04-21T16:48:29.011Z2025-04-21T16:48:29.011ZS-EPMC90490683549526610.1039/c9ra07894k