Conjugated microporous polymers as a novel generation of drug carriers: A systemic study toward efficient carriers of tetracycline antibiotic

Abstract

Herein, a novel approach for synthesizing three distinct types of conjugated microporous polymers (CMPs) is presented. The method involves utilizing 2,1,3-benzothiadiazole (BBT) as a common monomeric unit, along with other monomeric units such as triphenylamine (TPA), tetraphenylethylene (TPE), and pyrene (Py), which exhibit varying levels of planarity. The synthesis of CMPs is achieved through a Suzuki coupling condensation reaction involving 4,7-dibromo-2,1,3-benzothiadiazole (BBT-Br2) and 1,4-benzeneboronic acid [PhB(OH)2]. The resulting CMPs possess unique structural characteristics, adjustable pore sizes, and exceptional chemical and physical properties, thereby surpassing other existing materials in their performance. Notably, these CMPs demonstrate favorable thermal stability and porosity comparable to previously reported CMPs in the literature. Among the synthesized CMPs, the TPE-Ph-BBT CMP exhibits the highest thermal stability, with a char yield of 72 wt%. Additionally, the biocompatibility and toxicity of the CMPs are assessed using an MTT assay and a live/dead cell viability assay. The findings reveal that the CMPs exhibit low toxicity and outstanding biocompatibility, as evidenced by cell viability values exceeding 90% after 24 or 48 h of incubation. Thus, these CMPs hold significant potential for biomedical applications. Furthermore, the CMPs can effectively serve as drug carriers for tetracycline antibiotics. The antimicrobial activity of tetracycline (TCH)-loaded CMPs is evaluated using an inhibition zone methodology, demonstrating wide zones of inhibition measuring up to 1.7 cm against Staphylococcus aureus (S. aureus) and 1.9 cm against Escherichia coli (E. coli). This study highlights the promising prospects of CMPs in molecular engineering and their utility in diverse therapeutic applications as efficient drug carriers.