Dendrimer (PAMAM)-promoted pH-responsive membranes: Exploring open and close gate configurations for doxorubicin separation

Abstract

This research explores the separation of the antitumor drug doxorubicin (DOX) using smart membranes that respond to pH changes. To address the challenge of evaluating the efficiency of membranes with open and close gates, four types of membranes were synthesized: open gate (PADD0/PSf), bifunctional open gate (PADD1/PSf), close gate (PAADD0/PSf), and a combination of close/open gate (PAADD1/PSf). The results demonstrated that open gate membranes effectively separated DOX through molecular screening mechanism, with enhanced performance achieved through bi-functionalization and pH adjustments. The PADD0/PSf membrane exhibited a 93 % rejection rate at pH 7, which increased to approximately 99 % for the bifunctional PADD1/PSf at pH 2.7. In contrast, the PAADD0/PSf close gate membrane revealed only an 87 % rejection rate at pH 7, relying on Donnan repulsion for separation while achieving higher flux. Given the significance of treatment rates in membrane processes, the PADD0/PSf and PADD1/PSf membranes recorded fluxes of 4.6 LMH and 5 LMH at pH 7, respectively, while the PAADD0/PSf close gate membrane exhibited a significantly higher flux (226 %). The PAADD1/PSf close/open gate membrane was synthesized to optimize both separation and flux, achieving the highest flux at pH 2.7 with a 90 % DOX separation rate. At pH 11.2, it reached a separation rate of 95 % with a flux of 21 LMH, surpassing all other membranes across different pHs. Overall performance assessments indicated that PAADD1/PSf achieved an overall performance parameter of 1704 at pH = 2.7, compared to values of 78 for PADD0/PSf, 90 for PADD1/PSf, and 727 for PAADD1/PSf. © 2025 Elsevier Ltd