Boronic Acid Functionalized Photosensitizers: A Strategy To Target the Surface of Bacteria and Implement Active Agents in Polymer Coatings

Abstract

Advanced methods for preventing and controlling hospital-acquired infections via eradication of free-floating bacteria and bacterial biofilms are of great interest. In this regard, the attractiveness of unconventional treatment modalities such as antimicrobial photodynamic therapy (aPDT) continues to grow. This study investigated a new and innovative strategy for targeting polysaccharides found on the bacterial cell envelope and the biofilm matrix using the boronic acid functionalized and highly effective photosensitizer (PS) silicon(IV) phthalocyanine. This strategy has been found to be successful in treating planktonic cultures and biofilms of Gram-negative E. coli. An additional advantage of boronic acid functionality is a possibility to anchor the tailor made PS to poly(vinyl alcohol) and to fabricate a self-disinfecting coating.

Gaining Access to Bacteria through (Reversible) Control of Lipophilicity

“…For instance, tetra‐ and octa‐cationic silicon(IV) phthalocyanines bearing four or eight N‐methylated pyridoxy substituents at their periphery were proven to be inefficient for the photodynamic inactivation of Gram‐negative E. coli . In our recent study, we showed that boronic acid functionality can confer activity to a tetra‐cationic silicon(IV) phthalocyanine by substantially increasing the local concentration of PS . Greater photobactericidal efficacy of toluidine blue in comparison to methylene blue was also found to be due to the stronger interaction of the former with LPS components .…”

“…Although several factors that are important in the photodynamic efficiency of silicon(IV) phthalocyanines (SiPcs) have been described previously,, they have not been consistently evaluated. In an effort to clarify this, a comprehensive study was undertaken to determine the impact of lipophilicity and host–guest complexation on the molecular features of 2(3),9(10),16(17),23(24)‐tetrakis(3‐pyridyloxy)phthalocyaninato dihydroxy‐silicon(IV) and its aPDT efficacy.…”

Design of an Amphiphilic Perylene Diimide for Optical Recognition of Anticancer Drug through a Chirality‐Induced Helical Structure

“…No significant changes were observed in the absorption (Figures S3 aa nd S4 a, Supporting Information), lifetimes( Figures S3 ca nd S4 c), and CD spectra ( Figures S3 da nd S4 d) of PDI-PBA in presence of DA and d-Glu, respectively.M oreover,a ss hown in Figure 2b and Figures S3 ba nd S4 b, both DA and d-Glu significantlyq uenched the fluorescenceo fP DI-PBA. d-Glu led to fluorescenceq uenching of PDI-PBA probablyd ue to slight aggregation of PDI-PBA, [19] since the energy levelsw ere not favorable for PET (Figure2c). In addition, 2'DU possessing trans-diol units displayed less of af luorescencer esponse, indicating the key role of the cis-position of the diol unit over trans in the molecular recognition process.F or other chiral anticancerd rugs DOX, CPT,a nd PTX, slight fluorescencec hanges of PDI-PBAw ere observed whereas only 5'DFU could significantly enhance the fluorescence of PDI-PBA.…”

Carbohydrate‐Responsive Surface Adhesion Based on the Dynamic Covalent Chemistry of Phenylboronic Acid‐ and Catechol‐Containing Polymer Brushes

“…[13] As imilar concept exploiting the redox-responsive host-guest chemistry of cyclodextrin and ferrocene was reported by Yane tal. [21][22][23][24][25][26] An alternative way for the use of catechols and boronic acids in materials is the preparation of polymers to obtain multivalent interactions.A ni nteresting approach was reported by Messersmith et al who investigated apHresponsive self-healing hydrogel by boronate-catechol complexation. [15] This type of chemistry exploits covalent yet reversible bonds,w hich are in at hermodynamic equilibrium and respond readily to changes in composition.…”