Co-assembled Nanoparticles Towards Multi-target Combinational Therapy of Alzheimer's Disease by Making Full Use of Molecular Recognition and Self-assembly.

The complex pathologies in Alzheimer's disease (AD) severely limits the effectiveness of single-target pharmic interventions, thus necessitating multi-pronged therapeutic strategies. While flexibility is essentially demanded in constructing such multi-target systems, for achieving optimal synergies and also accommodating the inherent heterogeneity within AD. Utilizing the dynamic reversibility of supramolecular strategy for conferring sufficient tunability in component substitution and proportion adjustment, amphiphilic calixarenes are poised to be a privileged molecular tool for facilely achieving function integration. Herein, taking ß-amyloid (Aß) fibrillation and oxidative stress as model combination pattern, we proposed a supramolecular multifunctional integration by co-assembling guanidinium-modified calixarene with ascorbyl palmitate and loading dipotassium phytate within calixarene cavity. Serial pivotal events can be simultaneously addressed by this versatile system, including (1) inhibition of Aß production and aggregation, (2) disintegration of Aß fibrils, (3) acceleration of Aß metabolic clearance, and (4) regulation of oxidative stress, which is verified to significantly ameliorate the cognitive impairment of 5×FAD mice, with reduced Aß plaque content, neuroinflammation and neuronal apoptosis. Confronted with the extremely intricate clinical realities of AD, the strategy presented here exhibits ample adaptability for necessary alterations on combinations, thereby may immensely expedite the advancement of AD combinational therapy through providing an exceptionally convenient platform. This article is protected by copyright. All rights reserved.

A universal strategy to enhance photothermal conversion efficiency by regulating the molecular aggregation states for safe photothermal therapy of bacterial infections.

Photothermal therapy (PTT) has emerged as a promising approach for treating bacterial infections. However, achieving a high photothermal conversion efficiency (PCE) of photothermal agents (PTAs) remains a challenge. Such a problem is usually compensated by the use of a high-intensity laser, which inevitably causes tissue damage. Here, we present a universal strategy to enhance PCE by regulating the molecular aggregation states of PTAs within thermoresponsive nanogels. We demonstrate the effectiveness of this approach using aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) PTAs, showing significant enhancements in PCE without the need for intricate molecular modifications. Notably, the highest PCEs reach up to 80.9% and 64.4% for AIE-NG and ACQ-NG, respectively, which are nearly 2-fold of their self-aggregate counterparts. Moreover, we elucidate the mechanism underlying PCE enhancement, highlighting the role of strong intermolecular π-π interactions facilitated by nanogel-induced volume contraction. Furthermore, we validate the safety and efficacy of this strategy in in vitro and in vivo models of bacterial infections at safe laser power densities, demonstrating its potential for clinical translation. Our findings offer a straightforward, universal, and versatile method to improve PTT outcomes while minimizing cytotoxicity, paving the way for enhanced treatment of bacterial infections with safe PTT protocols.

Beyond surface modification strategies to control infections associated with implanted biomaterials and devices - Addressing the opportunities offered by nanotechnology.

Biomaterial-associated infection (BAI) is considered a unique infection due to the presence of a biomaterial yielding frustrated immune-cells, ineffective in clearing local micro-organisms. The involvement of surface-adherent/surface-adapted micro-organisms in BAI, logically points to biomaterial surface-modifications for BAI-control. Biomaterial surface-modification is most suitable for prevention before adhering bacteria have grown into a mature biofilm, while BAI-treatment is virtually impossible through surface-modification. Hundreds of different surface-modifications have been proposed for BAI-control but few have passed clinical trials due to the statistical near-impossibility of benefit-demonstration. Yet, no biomaterial surface-modification forwarded, is clinically embraced. Collectively, this leads us to conclude that surface-modification is a dead-end road. Accepting that BAI is, like most human infections, due to surface-adherent biofilms (though not always to a foreign material), and regarding BAI as a common infection, opens a more-generally-applicable and therewith easier-to-validate road. Pre-clinical models have shown that stimuli-responsive nano-antimicrobials and antibiotic-loaded nanocarriers exhibit prolonged blood-circulation times and can respond to a biofilm's micro-environment to penetrate and accumulate within biofilms, prompt ROS-generation and synergistic killing with antibiotics of antibiotic-resistant pathogens without inducing further antimicrobial-resistance. Moreover, they can boost frustrated immune-cells around a biomaterial reducing the importance of this unique BAI-feature. Time to start exploring the nano-road for BAI-control.

A supramolecular hydrogel dressing with antibacterial, immunoregulation, and pro-regeneration ability for biofilm-associated wound healing.

Chronic wound treatment has emerged as a significant healthcare concern worldwide due to its substantial economic burden and the limited effectiveness of current treatments. Effective management of biofilm infections, regulation of excessive oxidative stress, and promotion of tissue regeneration are crucial for addressing chronic wounds. Hydrogel stands out as a promising candidate for chronic wound treatment. However, its clinical application is hindered by the difficulty in designing and fabricating easily and conveniently. To overcome these obstacles, we present a supermolecular G-quadruplex hydrogel with the desired multifunction via a dynamic covalent strategy and Hoogsteen-type hydrogen bonding. The G-quadruplex hydrogel is made from the self-assembly of guanosine, 2-formylphenyboronic acid, polyethylenimine, and potassium chloride, employing dynamic covalent strategy and Hoogsteen-type hydrogen bonding. In the acidic/oxidative microenvironment associated with bacterial infections, the hydrogel undergoes controlled degradation, releasing the polyethylenimine domain, which effectively eliminates bacteria. Furthermore, nanocomplexes comprising guanosine monophosphate and manganese sulfate are incorporated into the hydrogel skeleton, endowing it with the ability to scavenge reactive oxygen species and modulate macrophages. Additionally, the integration of basic fibroblast growth factor into the G-quadruplex skeleton through dynamic covalent bonds facilitates controlled tissue regeneration. In summary, the facile preparation process and the incorporation of multiple functionalities render the G-quadruplex hydrogel a highly promising candidate for advanced wound dressing. It holds great potential to transition from laboratory research to clinical practice, addressing the pressing needs of chronic wound management.

A normalized parameter for comparison of biofilm dispersants in vitro.

Dispersal of infectious biofilms increases bacterial concentrations in blood. To prevent sepsis, the strength of a dispersant should be limited to allow the immune system to remove dispersed bacteria from blood, preferably without antibiotic administration. Biofilm bacteria are held together by extracellular polymeric substances that can be degraded by dispersants. Currently, comparison of the strength of dispersants is not possible by lack of a suitable comparison parameter. Here, a biofilm dispersal parameter is proposed that accounts for differences in initial biofilm properties, dispersant concentration and exposure time by using PBS as a control and normalizing outcomes with respect to concentration and time. The parameter yielded near-identical values based on dispersant-induced reductions in biomass or biofilm colony-forming-units and appeared strain-dependent across pathogens. The parameter as proposed is largely independent of experimental methods and conditions and suitable for comparing different dispersants with respect to different causative strains in particular types of infection.

Controlled Refolding of Denatured IL-12 Using In Situ Antigen-Capturing Nanochaperone Remarkably Reduces the Systemic Toxicity and Enhances Cancer Immunotherapy.

Cytokines are powerful in cancer immunotherapy, however, their therapeutic potential is limited by the severe systemic toxicity. Here a potent strategy to reduce the toxicity of systemic cytokine therapy by delivering its denatured form using a finely designed nanochaperone, is described. It is demonstrated that even if the denatured protein cargos are occasionally released under normal physiological conditions they are still misfolded, while can effectively refold into native states and release to function in tumor microenvironment. Consequently, the systemic toxicity of cytokines is nearly completely overcome. Moreover, an immunogenic cell death (ICD)-inducing chemotherapeutic is further loaded and delivered to tumor using this nanochaperone to trigger the release of tumor-associated antigens (TAAs) that are subsequently captured in situ by nanochaperone and then reflows into lymph nodes (LNs) to promote antigen cross-presentation. This optimized personalized nanochaperone-vaccine demonstrates unprecedented suppressive effects against large, advanced tumors, and in combination with immune checkpoint blockade (ICB) therapy results in a significant abscopal effect and inhibition of postoperative tumor recurrence and metastasis. Hence, this approach provides a simple and universal delivery strategy to reduce the systemic toxicities of cytokines, as well as provides a robust personalized cancer vaccination platform, which may find wide applications in cancer immunotherapy.

Rational design of ICD-inducing nanoparticles for cancer immunotherapy.

Nanoparticle-based cancer immunotherapy has shown promising therapeutic potential in clinical settings. However, current research mainly uses nanoparticles as delivery vehicles but overlooks their potential to directly modulate immune responses. Inspired by the endogenous endoplasmic reticulum (ER) stress caused by unfolded/misfolded proteins, we present a rationally designed immunogenic cell death (ICD) inducer named NanoICD, which is a nanoparticle engineered for ER targeting and retention. By carefully controlling surface composition and properties, we have obtained NanoICD that can effectively accumulate in the ER, induce ER stress, and activate ICD-associated immune responses. In addition, NanoICD is generally applicable to various proteins and enzymes to further enhance the immunomodulatory capacity, exemplified by encapsulating catalase (CAT) to obtain NanoICD/CAT, effectively alleviated immunosuppressive tumor microenvironment and induced robust antitumor immune responses in 4T1-bearing mice. This work demonstrates engineered nanostructures' potential to autonomously regulate biological processes and provides insights into the development of advanced nanomedicines for cancer treatment.

Metal-Phenolic Network with Pd Nanoparticle Nodes Synergizes Oxidase-Like and Photothermal Properties to Eradicate Oral Polymicrobial Biofilm-Associated Infections.

Designing an effective treatment strategy to combat oral diseases caused by complex polymicrobial biofilms remains a great challenge. Herein, a series of metal-phenolic network with Pd nanoparticle nodes using polyphenols as stabilizers and reducing agents is constructed. Among them, sulfonated lignin-Pd (SLS-Pd) with ultrafine size palladium nanoparticles and broadband near infrared absorption exhibit excellent oxidase-like activity and stable photothermal effect. In vitro experiments demonstrate that the superoxide radical generated by SLS-Pd oxidase-like activity exhibits selective antibacterial effects, while its photothermal effect induced hyperthermia exhibits potent antifungal properties. This difference is further elucidated by RNA-sequencing analysis and all-atom simulation. Moreover, the SLS-Pd-mediated synergistic antimicrobial system exhibits remarkable efficacy in combating various biofilms and polymicrobial biofilms. By establishing a root canal model and an oropharyngeal candidiasis model, the feasibility of the synergistic antimicrobial system in treating oral biofilm-related infections is further validated. This system provides a promising therapeutic approach for polymicrobial biofilm-associated infections in the oral cavity.

Recent advances and prospects in nanomaterials for bacterial sepsis management.

Bacterial sepsis is a life-threatening condition caused by bacteria entering the bloodstream and triggering an immune response, underscoring the importance of early recognition and prompt treatment. Nanomedicine holds promise for addressing sepsis through improved diagnostics, nanoparticle biosensors for detection and imaging, enhanced antibiotic delivery, combating resistance, and immune modulation. However, challenges remain in ensuring safety, regulatory compliance, scalability, and cost-effectiveness before clinical implementation. Further research is needed to optimize design, efficacy, safety, and regulatory strategies for effective utilization of nanomedicines in bacterial sepsis diagnosis and treatment. This review highlights the significant potential of nanomedicines, including improved drug delivery, enhanced diagnostics, and immunomodulation for bacterial sepsis. It also emphasizes the need for further research to optimize design, efficacy, safety profiles, and address regulatory challenges to facilitate clinical translation.

Development of self-cooperative nanochaperones with enhanced activity to facilitate protein refolding.

Regulating protein folding including assisting de novo folding, preventing misfolding and aggregation, and facilitating refolding of proteins are of significant importance for retaining protein's biological activities. Here, we report a mixed shell polymeric micelle (MSPM)-based self-cooperative nanochaperone (self-CO-nChap) with enhanced activity to facilitate protein refolding. This self-CO-nChap was fabricated by introducing Hsp40-mimetic artificial carriers into the traditional nanochaperone to cooperate with the Hsp70-mimetic confined hydrophobic microdomains. The artificial carrier facilitates transfer and immobilization of client proteins into confined hydrophobic microdomains, by which significantly improving self-CO-nChap's capability to inhibit unfolding and aggregation of client proteins, and finally facilitating refolding. Compared to traditional nanochaperones, the self-CO-nChap significantly enhances the thermal stability of horseradish peroxidase (HRP) epicyclically under harsher conditions. Moreover, the self-CO-nChap efficiently protects misfolding-prone proteins, such as immunoglobulin G (IgG) antibody from thermal denaturation, which is hardly achieved using traditional nanochaperones. In addition, a kinetic partitioning mechanism was devised to explain how self-CO-nChap facilitates refolding by regulating the cooperative effect of kinetics between the nanochaperone and client proteins. This work provides a novel strategy for the design of protein folding regulatory materials, including nanochaperones.

Multifunctional Polymer Vesicles for Synergistic Antibiotic-Antioxidant Treatment of Bacterial Keratitis.

As an acute ophthalmic infection, bacterial keratitis (BK) can lead to severe visual morbidity, such as corneal perforation, intraocular infection, and permanent corneal opacity, if rapid and effective treatments are not available. In addition to eradicating pathogenic bacteria, protecting corneal tissue from oxidative damage and promoting wound healing by relieving inflammation are equally critical for the efficient treatment of BK. Besides, it is very necessary to improve the bioavailability of drugs by enhancing the ocular surface adhesion and corneal permeability. In this investigation, therefore, a synergistic antibiotic-antioxidant treatment of BK was achieved based on multifunctional block copolymer vesicles, within which ciprofloxacin (CIP) was simultaneously encapsulated during the self-assembly. Due to the phenylboronic acid residues in the corona layer, these vesicles exhibited enhanced muco-adhesion, deep corneal epithelial penetration, and bacteria-targeting, which facilitated the drug delivery to corneal bacterial infection sites. Additionally, the abundant thioether moieties in the hydrophobic membrane enabled the vesicles to both have ROS-scavenging capacity and accelerated CIP release at the inflammatory corneal tissue. In vivo experiments on a mice model demonstrated that the multifunctional polymer vesicles achieved efficient treatment of BK, owing to the enhanced corneal adhesion and penetration, bacteria targeting, ROS-triggered CIP release, and the combined antioxidant-antibiotic therapy. This synergistic strategy holds great potential in the treatment of BK and other diseases associated with bacterial infections.

Self-Assembly Nanochaperone with Tunable Hydrophilic-Hydrophobic Surface for Controlled Protein Refolding.

Nanochaperones (nChaps) have significant potential to inhibit protein aggregation and assist in protein refolding. The interaction between nChaps and proteins plays an important role in nChaps performing chaperone-like functions, but the interaction mechanism remains elusive. In this work, a series of nChaps with tunable hydrophilic-hydrophobic surfaces are prepared, and the process of nChaps-assisted denatured protein refolding is systematically explored. It is found that an appropriate hydrophilic-hydrophobic balance on the nChap surface is critical for enhancing protein renaturation. This is because only the optimal interaction between nChap and protein can simultaneously guarantee the suitable capture and sufficient release of client proteins. The findings in this work will provide an effective reference for the design of nChaps and contribute to the development of the potential of nChaps in the future.

Supramolecular Photothermal Cascade Nano-Reactor Enables Photothermal Effect, Cascade Reaction, and In Situ Hydrogelation for Biofilm-Associated Tooth-Extraction Wound Healing.

Due to the emergence of drug resistance in bacteria and biofilm protection, achieving a satisfactory therapeutic effect for bacteria-infected open wounds with conventional measures is problematic. Here, a photothermal cascade nano-reactor (CPNC@GOx-Fe2+ ) is constructed through a supramolecular strategy through hydrogen bonding and coordination interactions between chitosan-modified palladium nano-cube (CPNC), glucose oxidase (GOx), and ferrous iron (Fe2+ ). CPNC@GOx-Fe2+ exhibits excellent photothermal effects and powers the GOx-assisted cascade reaction to generate hydroxyl radicals, enabling photothermal and chemodynamic combination therapy against bacteria and biofilms. Further proteomics, metabolomics, and all-atom simulation results indicate that the damage of the hydroxyl radical to the function and structure of the cell membrane and the thermal effect enhance the fluidity and inhomogeneity of the bacterial cell membrane, resulting in the synergistic antibacterial effect. In the biofilm-associated tooth extraction wound model, the hydroxyl radical generated from the cascade reaction process can initiate the radical polymerization process to form a hydrogel in situ for wound protection. In vivo experiments confirm that synergistic antibacterial and wound protection can accelerate the healing of infected tooth-extraction wounds without affecting the oral commensal microbiota. This study provides a way to propose a multifunctional supramolecular system for the treatment of open wound infection.

Activated alkyne-enabled turn-on click bioconjugation with cascade signal amplification for ultrafast and high-throughput antibiotic screening.

Antimicrobial susceptibility testing plays a pivotal role in the discovery of new antibiotics. However, the development of simple, sensitive, and rapid assessment approaches remains challenging. Herein, we report an activated alkyne-based cascade signal amplification strategy for ultrafast and high-throughput antibiotic screening. First of all, a novel water-soluble aggregation-induced emission (AIE) luminogen is synthesized, which contains an activated alkyne group to enable fluorescence turn-on and metal-free click bioconjugation under physiological conditions. Taking advantage of the in-house established method for bacterial lysis, a number of clickable biological substances (i.e., bacterial solutes and debris) are released from the bacterial bodies, which remarkably increases the quantity of analytes. By means of the activated alkyne-mediated turn-on click bioconjugation, the system fluorescence signal is significantly amplified due to the increased labeling sites as well as the AIE effect. Such a cascade signal amplification strategy efficiently improves the detection sensitivity and thus enables ultrafast antimicrobial susceptibility assessment. By integration with a microplate reader, this approach is further applied to high-throughput antibiotic screening.

Two-Tailed Dynamic Covalent Amphiphile Combats Bacterial Biofilms.

Drug combination provides an efficient pathway to combat drug resistance in bacteria and bacterial biofilms. However, the facile methodology to construct the drug combinations and their applications in nanocomposites is still lacking. Here the two-tailed antimicrobial amphiphiles (T2 A2 ) composed of nitric oxide (NO)-donor (diethylenetriamine NONOate, DN) and various natural aldehydes are reported. T2 A2 self-assemble into nanoparticles due to their amphiphilic nature, with remarkably low critical aggregation concentration. The representative cinnamaldehyde (Cin)-derived T2 A2 (Cin-T2 A2 ) assemblies demonstrate excellent bactericidal efficacy, notably higher than free Cin and free DN. Cin-T2 A2 assemblies kill multidrug-resistant staphylococci and eradicate their biofilms via multiple mechanisms, as proved by mechanism studies, molecular dynamics simulations, proteomics, and metabolomics. Furthermore, Cin-T2 A2 assemblies rapidly eradicate bacteria and alleviate inflammation in the subsequent murine infection models. Together, the Cin-T2 A2 assemblies may provide an efficient, non-antibiotic alternative in combating the ever-increasing threat of drug-resistant bacteria and their biofilms.

Dynamic covalent nano-networks comprising antibiotics and polyphenols orchestrate bacterial drug resistance reversal and inflammation alleviation.

New antimicrobial strategies are urgently needed to meet the challenges posed by the emergence of drug-resistant bacteria and bacterial biofilms. This work reports the facile synthesis of antimicrobial dynamic covalent nano-networks (aDCNs) composing antibiotics bearing multiple primary amines, polyphenols, and a cross-linker acylphenylboronic acid. Mechanistically, the iminoboronate bond drives the formation of aDCNs, facilitates their stability, and renders them highly responsive to stimuli, such as low pH and high H2O2 levels. Besides, the representative A1B1C1 networks, composed of polymyxin B1(A1), 2-formylphenylboronic acid (B1), and quercetin (C1), inhibit biofilm formation of drug-resistant Escherichia coli, eliminate the mature biofilms, alleviate macrophage inflammation, and minimize the side effects of free polymyxins. Excellent bacterial eradication and inflammation amelioration efficiency of A1B1C1 networks are also observed in a peritoneal infection model. The facile synthesis, excellent antimicrobial performance, and biocompatibility of these aDCNs potentiate them as a much-needed alternative in current antimicrobial pipelines.

Vaginal Drug Delivery Systems to Control Microbe-Associated Infections.

The vagina has been regarded as a crucial route for drug delivery. Despite the wide range of available vaginal dosage forms for vaginal infection control, poor drug absorptivity remains a significant challenge due to various biological barriers in the vagina, such as mucus, epithelium, immune systems, and others. To overcome these barriers, different types of vaginal drug delivery systems (VDDSs), with outstanding mucoadhesive, mucus-penetrating properties, have been designed to enhance the absorptivity of vagina-administered agents in the past decades. In this Review, we introduce a general understanding of vaginal administration, its biological barriers, the commonly used VDDSs, such as nanoparticles and hydrogels, and their applications in controlling microbe-associated vaginal infections. Additionally, further challenges and concerns regarding the design of VDDSs will be discussed.

Lipid Prodrug Nanoassemblies via Dynamic Covalent Boronates.

Prodrug nanoassemblies combine the advantages of prodrug and nanomedicines, offering great potential in targeting the lesion sites and specific on-demand drug release, maximizing the therapeutic performance while minimizing their side effects. However, there is still lacking a facile pathway to prepare the lipid prodrug nanoassemblies (LPNAs). Herein, we report the LPNAs via the dynamic covalent boronate between catechol and boronic acid. The resulting LPNAs possess properties like drug loading in a dynamic covalent manner, charge reversal in an acidic microenvironment, and specific drug release at an acidic and/or oxidative microenvironment. Our methodology enables the encapsulation and delivery of three model drugs: ciprofloxacin, bortezomib, and miconazole. Moreover, the LPNAs are often more efficient in eradicating pathogens or cancer cells than their free counterparts, both in vitro and in vivo. Together, our LPNAs with intriguing properties may boost the development of drug delivery and facilitate their clinical applications.