Design and Nanoengineering of Photoactive Antimicrobials for Bioapplications: from Fundamentals to Advanced Strategies

Abstract

Currently, microbial infections have posed an arduous challenge to global public health, whereas the rise of antibiotic resistance is rendering traditional antibiotic therapies futile, prompting the development of new antimicrobial technologies. Photoactive nanomaterials have thus garnered a thriving interest for disinfection owing to their superior antibacterial efficaciousness, favorable biosafety, and rapidness and spatiotemporal precision in excreting bactericidal actions. The review summarizes recent advances and emerging trends in the design, nanoengineering, and bioapplications of photoactive antimicrobials. It commences by elaborating fundamental theories on bacterial resistance, and antibacterial mechanisms of nanomaterials and phototherapy. Subsequently, the regulation of the antibacterial effectiveness of photoactive nanomaterials is comprehensively discussed, centering on criteria and strategies for tuning photoabsorption spectra, photothermal conversion, and photocatalytic efficiency, alongside tactics for enabling synergistic therapies. This is followed by comparative analyses of techniques and modalities for synthesizing and engineering photoactive nanomaterials with diverse structures, forms, and functionalities. Thereafter, the state‐of‐the‐art applications of phototherapies across various medical sectors are portrayed, and key challenges and opportunities are finally discussed to spur future innovations and translation. This review is envisaged to provide useful guidance for devising and developing nanomaterials‐based photoresponsive antimicrobials with application‐specific materials properties and biological functions.

Cu2O Nanocubes Embedded in Polycaprolactone Nanofibers for Photo–chemotherapeutic Wound Disinfection and Regeneration

“…, proteins and nucleic acids), leading to the denaturation and loss of function . Upon exposure to light, the active Cu 2 O NPs generated ROS and/or heat, which led to the damage of bacterial membrane and the oxidative damage of biomolecules . The synergistic photo–chemical effects endowed the mPCL-Cu 2 O scaffold with outstanding antibacterial and anti-infective properties (Figure h).…”

“…On the one hand, upon visible-light irradiation, the Cu 2 O NPs are excited to generate photogenerated electrons on the CB, leaving holes on VB. The photogenerated electrons were captured by O 2 , generating • O 2 – and other ROS . On the other hand, the Cu 2+ released from the mPCL-Cu 2 O per se could exert bacteriostatic effects.…”

“…The photogenerated electrons were captured by O 2 , generating • O 2 − and other ROS. 18 On the other hand, the Cu 2+ released from the mPCL-Cu 2 O per se could exert bacteriostatic effects. The synergistic actions of ROS and Cu 2+ lead to an antibacterial rate over 99% under a green LED lamp (0.2 W/cm 2 ).…”

“…42 Upon exposure to light, the active Cu 2 O NPs generated ROS and/or heat, which led to the damage of bacterial membrane and the oxidative damage of biomolecules. 18 The synergistic photo− chemical effects endowed the mPCL-Cu 2 O scaffold with outstanding antibacterial and anti-infective properties (Figure 4h). This comprehensive approach targeted bacteria through multiple mechanisms, enhancing the overall efficacy of the dressing in preventing and treating infections.…”

“…Owing to its low invasiveness, high spatiotemporal controllability, and rapidness in bacterial killing, phototherapy has propelled substantial interest over recent years for counteracting topical infections, such as those associated with diabetic foot ulcers, urinary tract injuries, and corneal and burn wounds. ,− Copper-derived semiconducting nanomaterials ( e.g. , CuO, Cu 2 O, CuS, and Cu 2 S) with narrow band gaps have been widely investigated to realize photodynamic therapy (PDT), in which photogenerated charges, due to electron–hole separation, react readily with water or oxygen to produce bactericidal species such as 1 O 2 , • OH, and • O 2 – .…”