Multivalent Nanosheet Antibody Mimics for Selective Microbial Recognition and Inactivation

Computer-aided nanodrug discovery: recent progress and future prospects

Nanodrugs, which utilise nanomaterials in disease prevention and therapy, have attracted considerable interest since their initial conceptualisation in the 1990s. Substantial efforts have been made to develop nanodrugs for overcoming the limitations of conventional drugs, such as low targeting efficacy, high dosage and toxicity, and potential drug resistance. Despite the significant progress that has been made in nanodrug discovery, the precise design or screening of nanomaterials with desired biomedical functions prior to experimentation remains a significant challenge. This is particularly the case with regard to personalised precision nanodrugs, which require the simultaneous optimisation of the structures, compositions, and surface functionalities of nanodrugs. The development of powerful computer clusters and algorithms has made it possible to overcome this challenge through in silico methods, which provide a comprehensive understanding of the medical functions of nanodrugs in relation to their physicochemical properties. In addition, machine learning techniques have been widely employed in nanodrug research, significantly accelerating the understanding of bio-nano interactions and the development of nanodrugs. This review will present a summary of the computational advances in nanodrug discovery, focusing on the understanding of how the key interfacial interactions, namely, surface adsorption, supramolecular recognition, surface catalysis, and chemical conversion, affect the therapeutic efficacy of nanodrugs. Furthermore, this review will discuss the challenges and opportunities in computer-aided nanodrug discovery, with particular emphasis on the integrated "computation + machine learning + experimentation" strategy that can potentially accelerate the discovery of precision nanodrugs.

Precise Capture and Dynamic Release of Circulating Liver Cancer Cells with Dual-Histidine-Based Cell Imprinted Hydrogels

Circulating tumor cells (CTCs) detection presents significant advantages in diagnosing liver cancer due to its noninvasiveness, real-time monitoring, and dynamic tracking. However, the clinical application of CTCs-based diagnosis is largely limited by the challenges of capturing low-abundance CTCs within a complex blood environment while ensuring them alive. Here, an ultrastrong ligand, l-histidine-l-histidine (HH), specifically targeting sialylated glycans on the surface of CTCs, is designed. Furthermore, HH is integrated into a cell-imprinted polymer, constructing a hydrogel with precise CTCs imprinting, high elasticity, satisfactory blood compatibility, and robust anti-interference capacities. These features endow the hydrogel with excellent capture efficiency (>95%) for CTCs in peripheral blood, as well as the ability to release CTCs controllably and alive. Clinical tests substantiate the accurate differentiation between liver cancer, cirrhosis, and healthy groups using this method. The remarkable diagnostic accuracy (94%), lossless release of CTCs, material reversibility, and cost-effectiveness ($6.68 per sample) make the HH-based hydrogel a potentially revolutionary technology for liver cancer diagnosis and single-cell analysis.

One-Stop Integrated Nanoagent for Bacterial Biofilm Eradication and Wound Disinfection

To meet the requirements of biomedical applications in the antibacterial realm, it is of great importance to explore nano-antibiotics for wound disinfection that can prevent the development of drug resistance and possess outstanding biocompatibility. Therefore, we attempted to synthesize an atomically dispersed ion (Fe) on phenolic carbon quantum dots (CQDs) combined with an organic photothermal agent (PTA) (Fe@SAC CQDs/PTA) via a hydrothermal/ultrasound method. Fe@SAC CQDs adequately exerted peroxidase-like activity while the PTA presented excellent photothermal conversion capability, which provided enormous potential in antibacterial applications. Based on our work, Fe@SAC CQDs/PTA exhibited excellent eradication of Escherichia coli (>99% inactivation efficiency) and Staphylococcus aureus (>99% inactivation efficiency) based on synergistic chemodynamic therapy (CDT) and photothermal therapy (PTT). Moreover, in vitro experiments demonstrated that Fe@SAC CQDs/PTA could inhibit microbial growth and promote bacterial biofilm destruction. In vivo experiments suggested that Fe@SAC CQDs/PTA-mediated synergistic CDT and PTT exhibited great promotion to wound disinfection and recovery effects. This work indicated that Fe@SAC CQDs/PTA could serve as a broad-spectrum antimicrobial nano-antibiotic, which was simultaneously beneficial for bacterial biofilm eradication, wound disinfection, and wound healing.

Nanomedicine for the Detection and Treatment of Ocular Bacterial Infections

Ocular bacterial infection is a prevalent cause of blindness worldwide, with substantial consequences for normal human life. Traditional treatments for ocular bacterial infections areless effective, necessitating the development of novel techniques to enable accurate diagnosis, precise drug delivery, and effective treatment alternatives. With the rapid advancement of nanoscience and biomedicine, increasing emphasis has been placed on multifunctional nanosystems to overcome the challenges posed by ocular bacterial infections. Given the advantages of nanotechnology in the biomedical industry, it can be utilized to diagnose ocular bacterial infections, administer medications, and treat them. In this review, the recent advancements in nanosystems for the detection and treatment of ocular bacterial infections are discussed; this includes the latest application scenarios of nanomaterials for ocular bacterial infections, in addition to the impact of their essential characteristics on bioavailability, tissue permeability, and inflammatory microenvironment. Through an in-depth investigation into the effect of sophisticated ocular barriers, antibacterial drug formulations, and ocular metabolism on drug delivery systems, this review highlights the challenges faced by ophthalmic medicine and encourages basic research and future clinical transformation based on ophthalmic antibacterial nanomedicine.

Rapid Identification and Monitoring of Multiple Bacterial Infections Using Printed Nanoarrays

Fast and accurate detection of microbial cells in clinical samples is highly valuable but remains a challenge. Here, a simple, culture-free diagnostic system is developed for direct detection of pathogenic bacteria in water, urine, and serum samples using an optical colorimetric biosensor. It consists of printed nanoarrays chemically conjugated with specific antibodies that exhibits distinct color changes after capturing target pathogens. By utilizing the internal capillarity inside an evaporating droplet, target preconcentration is achieved within a few minutes to enable rapid identification and more efficient detection of bacterial pathogens. More importantly, the scattering signals of bacteria are significantly amplified by the nanoarrays due to strong near-field localization, which supports a visualizable analysis of the growth, reproduction, and cell activity of bacteria at the single-cell level. Finally, in addition to high selectivity, this nanoarray-based biosensor is also capable of accurate quantification and continuous monitoring of bacterial load on food over a broad linear range, with a detection limit of 10 CFU mL^-1 . This work provides an accessible and user-friendly tool for point-of-care testing of pathogens in many clinical and environmental applications, and possibly enables a breakthrough in early prevention and treatment.

Computational Biomaterials: Computational Simulations for Biomedicine

With the flourishing development of material simulation methods (quantum chemistry methods, molecular dynamics, Monte Carlo, phase field, etc.), extensive adoption of computing technologies (high-throughput, artificial intelligence, machine learning, etc.), and the invention of high-performance computing equipment, computational simulation tools have sparked the fundamental mechanism-level explorations to predict the diverse physicochemical properties and biological effects of biomaterials and investigate their enormous application potential for disease prevention, diagnostics, and therapeutics. Herein, the term "computational biomaterials" is proposed and the computational methods currently used to explore the inherent properties of biomaterials, such as optical, magnetic, electronic, and acoustic properties, and the elucidation of corresponding biological behaviors/effects in the biomedical field are summarized/discussed. The theoretical calculation of the physiochemical properties/biological performance of biomaterials applied in disease diagnosis, drug delivery, disease therapeutics, and specific paradigms such as biomimetic biomaterials is discussed. Additionally, the biosafety evaluation applications of theoretical simulations of biomaterials are presented. Finally, the challenges and future prospects of such computational simulations for biomaterials development are clarified. It is anticipated that these simulations would offer various methodologies for facilitating the development and future clinical translations/utilization of versatile biomaterials.

Ligand-Mediated Exfoliation and Antibacterial Activity of 2H Transition-Metal Dichalcogenides

Transition-metal dichalcogenides (TMDs) exists mainly in two polymorphs, namely, 1T (metallic) and 2H (semiconducting). To tailor the characteristics and practical utility of TMDs for different applications, functionalization is essential. In our earlier studies, we have shown that functionalized 1T and 2H MoS₂ exhibit exceptionally high antibacterial activity. The functionalization and related biological applications of other 1T (chemically exfoliated) TMDs were reported, but regarding other 2H TMDs, the functionalization and antibacterial activity are not explored yet. Hence, here we prepared functionalized 2H TMDs such as WS₂, WSe₂, and MoSe₂ other than MoS₂ by using a positively charged thiolate surfactant ligand. Further, functionalized 2H TMDs were utilized for antibacterial activity against Gram-positive and Gram-negative bacteria for a comparative antibacterial analysis. Interestingly, we found disparity in activity among the functionalized 2H TMDs, that is, MoS₂ shows higher activity than WS₂ followed by MoSe₂ and WSe₂. The intracellular reactive oxygen species measurement was found to be in the order MoS₂ > WS₂ > MoSe₂ > WSe₂, which is solely responsible for variation in the activity of functionalized TMDs. These results indicate that the easy functionalization of all types TMDs by using thiol ligand and importance of core material should be considered while designing functionalized material for specific applications.

Bacterium-Sculpted Porphyrin-Protein-Iron Sulfide Clusters for Distinction and Inhibition of Staphylococcus aureus

Microbe-catalyzed surface modification is a promising method for the production of special targeting nanomaterials. A bacterium-selective material can be obtained by investigating the microbe-catalyzed mineralization of proteins. Herein, a novel method was fabricated for the biosynthesis of FeS-decorated porphyrin-protein clusters (P-CA@BE) via E. coli (Escherichia coli)-catalyzed bio-Fe(III) reduction and bio-sulfidation of porphyrin (P), caffeic acid (CA), and protein [bovine serum albumin (BSA)] assemblies. The assembly (P-CA@BSA) was identified by spectroscopic methods. Next, the P-CA@BSA assembly was transferred into FeS-decorated porphyrin-protein clusters (P-CA@BE) catalyzed by E. coli. There are partial β-folding proteins in P-CA@BE, which selectively recognize S. aureus (Staphylococcus aureus) and show different antibacterial properties against E. coli and S. aureus. Results demonstrate that the E. coli-catalyzed mineralization of the porphyrin-protein assembly is an effective method for the biosynthesis of S. aureus-sensitive metal-protein clusters.

Transition-Metal Dichalcogenide Artificial Antibodies with Multivalent Polymeric Recognition Phases for Rapid Detection and Inactivation of Pathogens

Antibodies are recognition molecules that can bind to diverse targets ranging from pathogens to small analytes with high binding affinity and specificity, making them widely employed for sensing and therapy. However, antibodies have limitations of low stability, long production time, short shelf life, and high cost. Here, we report a facile approach for the design of luminescent artificial antibodies with nonbiological polymeric recognition phases for the sensitive detection, rapid identification, and effective inactivation of pathogenic bacteria. Transition-metal dichalcogenide (TMD) nanosheets with a neutral dextran phase at the interfaces selectively recognized S. aureus, whereas the nanosheets bearing a carboxymethylated dextran phase selectively recognized E. coli O157:H7 with high binding affinity. The bacterial binding sites recognized by the artificial antibodies were thoroughly identified by experiments and molecular dynamics simulations, revealing the significance of their multivalent interactions with the bacterial membrane components for selective recognition. The luminescent WS₂ artificial antibodies could rapidly detect the bacteria at a single copy from human serum without any purification and amplification. Moreover, the MoSe₂ artificial antibodies selectively killed the pathogenic bacteria in the wounds of infected mice under light irradiation, leading to effective wound healing. This work demonstrates the potential of TMD artificial antibodies as an alternative to antibodies for sensing and therapy.