%0 Journal Article
%T Photoreactive silver-containing supramolecular polymers that form self-assembled nanogels for efficient antibacterial treatment.
%A Fesseha YA
%A Manayia AH
%A Liu PC
%A Su TH
%A Huang SY
%A Chiu CW
%A Cheng CC
%J J Colloid Interface Sci
%V 654
%N 0
%D 2024 Jan 15
%M 37898080
%F 9.965
%R 10.1016/j.jcis.2023.10.119
%X In this study, an efficient synthetic strategy and potential route to obtain a photo-reactive silver-containing cytosine-functionalized polypropylene glycol polymer (Ag-Cy-PPG) was developed by combining a hydrophilic oligomeric polypropylene glycol (PPG) backbone with dual pH-sensitive/photo-reactive cytosine-silver-cytosine (Cy-Ag-Cy) linkages. The resulting photo-responsive Ag-Cy-PPG holds great promise as a multifunctional biomedical material that generates spherical-like nanogels in water; the nanogels exhibit high antibacterial activity and thus may significantly enhance the efficacy of antibacterial treatment. Due to the formation of photo-dimerized Cy-Ag-Cy cross-linkages after UV irradiation, Ag-Cy-PPG converts into water-soluble cross-linked nanogels that possess a series of interesting chemical and physical properties, such as intense and stable fluorescence behavior, highly sensitive pH-responsive characteristics, on/off switchable phase transition behavior, and well-controlled release of silver ions (Ag+) in mildly acidic aqueous solution. Importantly, antibacterial tests clearly demonstrated that irradiated Ag-Cy-PPG nanogels exhibited strong antibacterial activity at low doses (MIC values of < 50 μg/mL) against gram-positive and gram-negative bacterial pathogens, whereas non-irradiated Ag-Cy-PPG nanogels did not inhibit the viability of bacterial pathogens. These results indicate that irradiated Ag-Cy-PPG nanogels undergo a highly sensitive structural change in the bacterial microenvironment due to their relatively unstable π-conjugated structures (compared to non-irradiated nanogels); this change results in a rapid structural response that promotes intracellular release of Ag+ and induces potent antibacterial ability. Overall, this newly created metallo-supramolecular system may potentially provide an efficient route to dramatically enhance the therapeutic effectiveness of antibacterial treatments.