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Background: Hematopoietic cell transplantation (HCT) recipients have reduced antibody titers to tetanus, diphtheria, and pertussis. Tdap is approved for revaccinating adult HCT recipients in the United States, whereas DTaP is not approved in this population. To our knowledge, no studies to date have compared responses to DTaP versus Tdap in adult HCT patients. We conducted a retrospective study comparing responses to DTaP versus Tdap vaccines in otherwise similar adult HCT patients in order to determine if one of these vaccines elicits superior antibody responses. Methods: We evaluated 43 allogeneic and autologous transplant recipients as a combined cohort and as separate subsets for vaccine specific antibody titers and proportion of strong vaccine responders. Subset analysis focused on the autologous transplant recipients. Results: Higher median antibody titers were found to all vaccine components among DTaP recipients (diphtheria p =.021, pertussis p =.020, tetanus p =.007). DTaP recipients also had more strong responders to diphtheria and pertussis (diphtheria p =.002, pertussis p =.006). Among the autologous HCT recipient subset, there were more strong responders to diphtheria (p =.036). Conclusions: Our data shows that post‐HCT vaccination with DTaP leads to higher antibody titers and more strong responders, which suggests that DTaP is more effective than Tdap in HCT recipients. [ABSTRACT FROM AUTHOR]

Nanozyme is defined as a nanomaterial‐based artificial enzyme. It has rapidly attracted interest and been regarded as a promising alternative to natural enzymes due to its low cost, high stability, and high activity. Many researchers have recently paid attention to the optical properties of nanozymes and have found a variety of nanozymes with excellent photoactivity, called photo‐responsive nanozymes. In this minireview, we briefly introduce the mechanisms of photo‐responsive nanozymes, especially for the relationship between the enzyme‐like activity and photoactivity. Some activity regulation strategies for improving the performance of photo‐responsive nanozymes are also summarized. Moreover, the synergy of enzyme‐like activity and photoactivity in biomedical applications will also be discussed, including cancer therapy, antibacteria, and biological detection. We believe this minireview will be of great significance for understanding the optical properties of nanozymes and applying them in biomedicine. [ABSTRACT FROM AUTHOR]

With the increasing spread of multidrug-resistant (MDR) bacteria worldwide, it is needed to develop antibiotics-alternative strategies for the treatment of bacterial infections. This work develops a multifunctional single-component palladium nanosheet (PdNS) with broad-spectrum and highly effective bactericidal activity against MDR bacteria. PdNS exerts its endogenous nanoknife (mechanical cutting) effect and peroxidase-like activity independent of light. Under near-infrared region (NIR) light irradiation, PdNS exhibits photothermal effect to produce local heat and meanwhile possesses photodynamic effect to generate 1 O 2 ; notably, PdNS has catalase-like activity-dependent extra photodynamic effect upon H 2 O 2 addition. PdNS+H 2 O 2 +NIR employs a collectively synergistic mechanism of nanoknife effect, peroxidase/catalase-like catalytic activity, photothermal effect, and photodynamic effect for bacterial killing. PdNS+H 2 O 2 +NIR causes compensatory elevated phospholipid biosynthesis, disordered energy metabolism, increased cellular ROS levels and excessive oxidative stress, and inhibited nucleic acid synthesis in bacteria. In mice, PdNS+H 2 O 2 +NIR gives >92.7% bactericidal rates at infected wounds and almost the full recovery of infected wounds, and it leads to extensive down-regulation of proinflammatory pathways and comprehensive up-regulation of wound healing pathways, conferring elevated inflammation resolution and meanwhile accelerated wound repair. PdNS+H 2 O 2 +NIR represents a highly efficient nanoplatform for photoenhanced treatment of superficial infections., (© 2024 Wiley‐VCH GmbH.)

Single-atom nanozymes (SAzymes) are emerging natural enzyme mimics and have attracted much attention in the biomedical field. SAzymes with Metal─N x sites designed on carbon matrixes are currently the mainstream in research. It is of great significance to further expand the types of SAzymes to enrich the nanozyme library. Single-atom alloys (SAAs) are a material in which single-atom metal sites are dispersed onto another active metal matrix, and currently, there is limited research on their enzyme-like catalytic performance. In this work, a biodegradable Pt 1 Pd SAA is fabricated via a simple galvanic replacement strategy, and for the first time reveals its intrinsic enzyme-like catalytic performance including catalase-, oxidase-, and peroxidase-like activities, as well as its photodynamic effect. Experimental characterizations demonstrate that the introduction of single-atom Pt sites contributes to enhancing the affinity of Pt 1 Pd single-atom alloy nanozyme (SAAzyme) toward substrates, thus exhibiting boosted catalytic efficiency. In vitro and in vivo experiments demonstrate that Pt 1 Pd SAAzyme exhibits a photo-controlled therapeutic effect, with a tumor inhibition rate of up to 100%. This work provides vital guidance for opening the research direction of SAAs in enzyme-like catalysis., (© 2023 Wiley‐VCH GmbH.)

Single-atom nanozymes (SAzymes), with well-defined and uniform atomic structures, are an emerging type of natural enzyme mimics. Currently, it is important but challenging to rationally design high-performance SAzymes and deeply reveal the interaction mechanism between SAzymes and substrate molecules. Herein, this work reports the controllable fabrication of a unique Cu-N 1 S 2 -centred SAzyme (Cu-N/S-C) via a chemical vapor deposition-based sulfur-engineering strategy. Benefiting from the optimized geometric and electronic structures of single-atom sites, Cu-N/S-C SAzyme shows boosted enzyme-like activity, especially in catalase-like activity, with a 13.8-fold increase in the affinity to hydrogen peroxide (H 2 O 2 ) substrate and a 65.2-fold increase in the catalytic efficiency when compared to Cu-N-C SAzyme with Cu-N 3 sites. Further theoretical studies reveal that the increased electron density around single-atom Cu is achieved through electron redistribution, and the efficient charge transfer between Cu-N/S-C and H 2 O 2 is demonstrated to be more beneficial for the adsorption and activation of H 2 O 2 . The as-designed Cu-N/S-C SAzyme possesses an excellent antitumor effect through the synergy of catalytic therapy and oxygen-dependent phototherapy. This study provides a strategy for the rational design of SAzymes, and the proposed electron redistribution and charge transfer mechanism will help to understand the coordination environment effect of single-atom metal sites on H 2 O 2 -mediated enzyme-like catalytic processes., (© 2023 Wiley‐VCH GmbH.)