Isoniazid@Fe2O3Nanocontainers and Their Antibacterial Effect on Tuberculosis Mycobacteria

Macrophage targeted iron oxide nanodecoys augment innate immunological and drug killings for more effective Mycobacterium Tuberculosis clearance

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) infection, is still one of the top killers worldwide among infectious diseases. The escape of Mtb from immunological clearance and the low targeting effects of anti-TB drugs remain the substantial challenges for TB control. Iron is particularly required for Mtb growth but also toxic for Mtb in high dosages, which makes iron an ideal toxic decoy for the 'iron-tropic' Mtb. Here, a macrophage-targeted iron oxide nanoparticles (IONPs)-derived IONPs-PAA-PEG-MAN nanodecoy is designed to augment innate immunological and drug killings against intracellular Mtb. IONPs-PAA-PEG-MAN nanodecoy exhibits preferential uptake in macrophages to significantly increase drug uptake with sustained high drug contents in host cells. Moreover, it can serve as a specific nanodecoy for the 'iron-tropic' Mtb to realize the localization of Mtb contained phagosomes surrounding the drug encapsulated nanodecoys and co-localization of Mtb with the drug encapsulated nanodecoys in lysosomes, where the incorporated rifampicin (Rif) can be readily released under acidic lysosomal condition for enhanced Mtb killing. This drug encapsulated nanodecoy can also polarize Mtb infected macrophages into anti-mycobacterial M1 phenotype and enhance M1 macrophage associated pro-inflammatory cytokine (TNF-α) production to trigger innate immunological responses against Mtb. Collectively, Rif@IONPs-PAA-PEG-MAN nanodecoy can synergistically enhance the killing efficiency of intracellular Mtb in in vitro macrophages and ex vivo monocyte-derived macrophages, and also significantly reduce the mycobacterial burdens in the lung of infected mice with alleviated pathology. These results indicate that Rif@IONPs-PAA-PEG-MAN nanodecoy may have a potential for the development of more effective therapeutic strategy against TB by manipulating augmented innate immunity and drug killings.

Promoting the healing of methicillin-resistant Staphylococcus aureus-infected wound by a multi-target antimicrobial AIEgen of 6-Aza-2-thiothymine-decorated gold nanoclusters

The use of conventional antibiotic therapies is in question owing to the emergence of drug-resistant pathogenic bacteria. Therefore, novel, highly efficient antibacterial agents to effectively overcome resistant bacteria are urgently needed. Accordingly, in this work, we described a novel class luminogen of 6-Aza-2-thiothymine-decorated gold nanoclusters (ATT-AuNCs) with aggregation-induced emission property that possessed potent antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA). Scanning electron microscopy was performed to investigate the interactions between ATT-AuNCs and MRSA. In addition, ATT-AuNCs exhibited excellent ROS generation efficiency and could effectively ablate MRSA via their internalization to the cells. Finally, tandem mass tag-labeling proteome analysis was carried out to investigate the differential expression proteins in MRSA strains. The results suggested that ATT-AuNCs killed MRSA cells through altering the expression of multiple target proteins involved in DNA replication, aminoacyl-tRNA synthesis, peptidoglycan and arginine biosynthesis metabolism. Parallel reaction monitoring technique was further used for the validation of these proteome results. ATT-AuNCs could also be served as a wound-healing agent and accelerate the healing process. Overall, we proposed ATT-AuNCs could serve as a robust antimicrobial aggregation-induced emission luminogen (AIEgen) that shows the ability to alter the activities of multiple targets for the elimination of drug-resistant bacteria.

Alloyed nanostructures integrated metal-phenolic nanoplatform for synergistic wound disinfection and revascularization

New materials for combating bacteria-caused infection and promoting the formation of microvascular networks during wound healing are of vital importance. Although antibiotics can be used to prevent infection, treatments that can disinfect and accelerate wound healing are scarce. Herein, we engineer a coating that is both highly compatible with current wound dressing substrates and capable of simultaneously disinfecting and revascularizing wounds using a metal-phenolic nanoplatform containing an alloyed nanostructured architecture (Ag@Cu-MPN_NC). The alloyed nanostructure is formed by the spontaneous co-reduction and catalytic disproportionation reaction of multiple metal ions on a foundation metal-phenolic supramolecular layer. This synergistic presence of metals greatly improves the antibacterial activity against both Gram-negative and Gram-positive pathogenic bacteria, while demonstrating negligible cytotoxicity to normal tissue. In infected rat models, the Ag@Cu-MPN_NC could kill bacteria efficiently, promoting revascularization and accelerate wound closure with no adverse side effects in infected in vivo models. In other words, this material acts as a combination therapy by inhibiting bacterial invasion and modulating bio-nano interactions in the wound.

Progress in the Application of Carbon Dots-Based Nanozymes

As functional nanomaterials with simulating enzyme-like properties, nanozymes can not only overcome the inherent limitations of natural enzymes in terms of stability and preparation cost but also possess design, versatility, maneuverability, and applicability of nanomaterials. Therefore, they can be combined with other materials to form composite nanomaterials with superior performance, which has garnered considerable attention. Carbon dots (CDs) are an ideal choice for these composite materials due to their unique physical and chemical properties, such as excellent water dispersion, stable chemical inertness, high photobleaching resistance, and superior surface engineering. With the continuous emergence of various CDs-based nanozymes, it is vital to thoroughly understand their working principle, performance evaluation, and application scope. This review comprehensively discusses the recent advantages and disadvantages of CDs-based nanozymes in biomedicine, catalysis, sensing, detection aspects. It is expected to provide valuable insights into developing novel CDs-based nanozymes.

Tumor microenvironment-triggered in situ cancer vaccines inducing dual immunogenic cell death for elevated antitumor and antimetastatic therapy

Cancer vaccines are made from tumor-specific antigens, which are then injected back into the body to activate immune responses for cancer immunotherapy. Despite the high specificity and therapeutic efficiency, the vaccine has huge challenges such as complex preparation process, expensiveness and limited durational effects. Herein, a strategy to develop in situ cancer vaccines by enhancing the immunomodulatory effects for immunogenic cell death (ICD) is presented. First, amorphous iron oxide-packaged oxaliplatin (AIOoxp) nanoprodrugs with a high drug loading efficiency of 12.9% were prepared. By utilizing tumor microenvironment (TME) as an endogenous stimulus, this inorganic nanoprodrug can effectively realize TME-responsive combined treatments of chemotherapy and chemodynamic therapy (CDT), and thus achieve dual and precise ICD induction. Further, in vivo immunopotentiation performances further prove that this enhanced ICD effect is able to efficiently promote the maturity of dendritic cells (DCs), T cell activation and correlative cytokine secretion. Furthermore, the obtained nanoprodrugs not only reduce systemic toxicities of Oxp and achieve T1/T2 magnetic resonance imaging (MRI), but also dramatically inhibit tumor growth and lung metastasis. We believe that the design of in situ cancer vaccines by enhancing the ICD effects will inspire future studies on cancer vaccines.

An overview of zinc oxide nanoparticles produced by plant extracts for anti-tuberculosis treatments

Tuberculosis (TB), induced by Mycobacterium tuberculosis (MTB), is a fatal infectious disease that kills millions of lives worldwide. The emergence of drug-resistant and multidrug-resistant cases is regarded as one of the most challenging threats to TB control due to the low cure rate. Therefore, TB and drug-resistant TB epidemics urge us to explore more effective therapies. The increasing knowledge of nanotechnology has extended to some nanomedicines for disease treatment in the clinic, which also provides novel possibilities for nano-based medicines for TB treatment. Zinc oxide nanoparticles (ZnO NPs) have gained increasing attention for anti-bacterial uses based on their strong ability to induce reactive oxidative species (ROS) and release bactericidal Zinc ions (Zn²⁺), which are expected to act as novel strategies for TB and drug-resistant TB treatment. Some active herbal medicines from plant extracts have been widely reported to show attractive anti-bacterial activity for infectious treatment, including TB. Here, we summarize the synthesis of ZnO NPs using plant extracts (green synthesized ZnO NPs) and further discuss their potentials for anti-TB treatments. This is the first review article discussing the anti-TB activity of ZnO NPs produced using plant extracts, which might contribute to the further applications of green synthesized ZnO NPs for anti-TB and drug-resistant TB treatment.

Iodine-doped carbon dots with inherent peroxidase catalytic activity for photocatalytic antibacterial and wound disinfection

A new type of nitrogen-iodine co-doped carbon dot (N/I-CD) was synthesized by a one-step hydrothermal method with a fluorescence quantum yield of 37%. The prepared N/I-CDs exhibit peroxidase-like activity, can catalyze bio-safety levels of H2O2 to generate hydroxyl radicals (•OH) under visible light and enhance the level of reactive oxygen species (ROS) in bacteria cells. All in vitro experiments showed that the designed system has strong photocatalytic antibacterial activity against both E. coli and S. aureus bacteria. The light-induced antibacterial function of N/I-CDs was evaluated under the conditions of changing other experimental parameters. When the visible light irradiation time was extended to 60 min, the antibacterial efficiency of N/I-CDs (0.21 mg·mL-1) against S. aureus and E. coli reached 100% in the presence of exogenous H2O2 (0.07 mM). More importantly, wound disinfection in vivo demonstrates the high antibacterial efficiency, low toxicity and application potential of good biocompatibility due to the nanozyme activity of N/I-CDs.

Nano-antimicrobials: A New Paradigm for Combating Mycobacterial Resistance

BACKGROUND

Mycobacterium group contains several pathogenic bacteria including M. tuberculosis where the emergence of multidrug-resistant tuberculosis (MDR-TB) and extensively drug-resistant tuberculosis (XDR-TB) is alarming for human and animal health around the world. The condition has further aggravated due to the speed of discovery of the newer drugs has been outpaced by the rate of resistance developed in microorganisms, thus requiring alternative combat strategies. For this purpose, nano-antimicrobials have emerged as a potential option.

OBJECTIVE

The current review is focused on providing a detailed account of nanocarriers like liposome, micelles, dendrimers, solid lipid NPs, niosomes, polymeric nanoparticles, nano-suspensions, nano-emulsion, mesoporous silica and alginate-based drug delivery systems along with the recent updates on developments regarding nanoparticle-based therapeutics, vaccines and diagnostic methods developed or under pipeline with their potential benefits and limitations to combat mycobacterial diseases for their successful eradication from the world in future.

RESULTS

Distinct morphology and the underlying mechanism of pathogenesis and resistance development in this group of organisms urge improved and novel methods for the early and efficient diagnosis, treatment and vaccination to eradicate the disease. Recent developments in nanotechnology have the potential to meet both the aspects: nano-materials are proven components of several efficient targeted drug delivery systems and the typical physicochemical properties of several nano-formulations have shown to possess distinct bacteriocidal properties. Along with the therapeutic aspects, nano-vaccines and theranostic applications of nano-formulations have grown in popularity in recent times as an effective alternative means to combat different microbial superbugs.

CONCLUSION

Nanomedicine holds a bright prospect to perform a key role in global tuberculosis elimination program.

Silver-Containing Titanium Dioxide Nanocapsules for Combating Multidrug-Resistant Bacteria

BACKGROUND

Joint arthroplasty has improved the quality of life of patients worldwide, but infections of the prosthesis are frequent and cause significant morbidity. Antimicrobial coatings for implants promise to prevent these infections.

METHODS

We have synthesized nanocapsules of titanium dioxide in amorphous or anatase form containing silver as antibacterial agent and tested their impact on bacterial growth. Furthermore, we explored the possible effect of the nanocapsules on the immune system. First, we studied their uptake into macrophages using a combination of electron microscopy and energy-dispersive spectroscopy. Second, we exposed immune cells to the nanocapsules and checked their activation state by flow cytometry and enzyme-linked immunosorbent assay.

RESULTS

Silver-containing titanium dioxide nanocapsules show strong antimicrobial activity against both E. coli and S. aureus and even against a multidrug-resistant strain of S. aureus. We could demonstrate the presence of the nanocapsules in macrophages, but, importantly, the nanocapsules did not affect cell viability and did not activate proinflammatory responses at doses up to 20 μg/mL.

CONCLUSION

Our bactericidal silver-containing titanium dioxide nanocapsules fulfill important prerequisites for biomedical use and represent a promising material for the coating of artificial implants.

Antitubercular nanocarrier monotherapy: Study of In Vivo efficacy and pharmacokinetics for rifampicin

Tuberculosis represents a major global health problem for which improved approaches are needed to shorten the course of treatment and to combat the emergence of resistant strains. The development of effective and safe nanobead-based interventions can be particularly relevant for increasing the concentrations of antitubercular agents within the infected site and reducing the concentrations in the general circulation, thereby avoiding off-target toxic effects. In this work, rifampicin, a first-line antitubercular agent, was encapsulated into biocompatible and biodegradable polyester-based nanoparticles. In a well-established BALB/c mouse model of pulmonary tuberculosis, the nanoparticles provided improved pharmacokinetics and pharmacodynamics. The nanoparticles were well tolerated and much more efficient than an equivalent amount of free rifampicin.

Multimodal X-ray imaging of nanocontainer-treated macrophages and calcium distribution in the perilacunar bone matrix

Studies of biological systems typically require the application of several complementary methods able to yield statistically-relevant results at a unique level of sensitivity. Combined X-ray fluorescence and ptychography offer excellent elemental and structural imaging contrasts at the nanoscale. They enable a robust correlation of elemental distributions with respect to the cellular morphology. Here we extend the applicability of the two modalities to higher X-ray excitation energies, permitting iron mapping. Using a long-range scanning setup, we applied the method to two vital biomedical cases. We quantified the iron distributions in a population of macrophages treated with Mycobacterium-tuberculosis-targeting iron-oxide nanocontainers. Our work allowed to visualize the internalization of the nanocontainer agglomerates in the cytosol. From the iron areal mass maps, we obtained a distribution of antibiotic load per agglomerate and an average areal concentration of nanocontainers in the agglomerates. In the second application we mapped the calcium content in a human bone matrix in close proximity to osteocyte lacunae (perilacunar matrix). A concurrently acquired ptychographic image was used to remove the mass-thickness effect from the raw calcium map. The resulting ptychography-enhanced calcium distribution allowed then to observe a locally lower degree of mineralization of the perilacunar matrix.

Macrophage-Targeted Isoniazid-Selenium Nanoparticles Promote Antimicrobial Immunity and Synergize Bactericidal Destruction of Tuberculosis Bacilli

Pathogenesis hallmarks for tuberculosis (TB) are the Mycobacterium tuberculosis (Mtb) escape from phagolysosomal destruction and limited drug delivery into infected cells. Several nanomaterials can be entrapped in lysosomes, but the development of functional nanomaterials to promote phagolysosomal Mtb clearance remains a big challenge. Here, we report on the bactericidal effects of selenium nanoparticles (Se NPs) against Mtb and further introduce a novel nanomaterial-assisted anti-TB strategy manipulating Ison@Man-Se NPs for synergistic drug-induced and phagolysosomal destruction of Mtb. Ison@Man-Se NPs preferentially entered macrophages and accumulated in lysosomes releasing Isoniazid. Surprisingly, Ison@Man-Se/Man-Se NPs further promoted the fusion of Mtb into lysosomes for synergistic lysosomal and Isoniazid destruction of Mtb. Concurrently, Ison@Man-Se/Man-Se NPs also induced autophagy sequestration of Mtb, evolving into lysosome-associated autophagosomal Mtb degradation linked to ROS-mitochondrial and PI3K/Akt/mTOR signaling pathways. This novel nanomaterial-assisted anti-TB strategy manipulating antimicrobial immunity and Mtb clearance may potentially serve in more effective therapeutics against TB and drug-resistant TB.

Rifampicin Nanoformulation Enhances Treatment of Tuberculosis in Zebrafish

Mycobacterium tuberculosis, the etiologic agent of tuberculosis, is an intracellular pathogen of alveolar macrophages. These cells avidly take up nanoparticles, even without the use of specific targeting ligands, making the use of nanotherapeutics ideal for the treatment of such infections. Methoxy poly(ethylene oxide)- block-poly(ε-caprolactone) nanoparticles of several different polymer blocks' molecular weights and sizes (20-110 nm) were developed and critically compared as carriers for rifampicin, a cornerstone in tuberculosis therapy. The polymeric nanoparticles' uptake, consequent organelle targeting and intracellular degradation were shown to be highly dependent on the nanoparticles' physicochemical properties (the cell uptake half-lives 2.4-21 min, the degradation half-lives 51.6 min-ca. 20 h after the internalization). We show that the nanoparticles are efficiently taken up by macrophages and are able to effectively neutralize the persisting bacilli. Finally, we demonstrate, using a zebrafish model of tuberculosis, that the nanoparticles are well tolerated, have a curative effect, and are significantly more efficient compared to a free form of rifampicin. Hence, these findings demonstrate that this system shows great promise, both in vitro and in vivo, for the treatment of tuberculosis.

Zirconyl Clindamycinphosphate Antibiotic Nanocarriers for Targeting Intracellular Persisting Staphylococcus aureus

[ZrO]²⁺[CLP]^2- (CLP: clindamycinphosphate) inorganic-organic hybrid nanoparticles (IOH-NPs) represent a novel strategy to treat persisting, recurrent infections with multiresistant Staphylococcus aureus. [ZrO]²⁺[CLP]^2- is prepared in water and contains the approved antibiotic with unprecedented high load (82 wt % CLP per nanoparticle). The IOH-NPs result in 70-150-times higher antibiotic concentrations at difficult-to-reach infection sites, offering new options for improved drug delivery for chronic and difficult-to-treat infections.

Engineering Multifunctional RNAi Nanomedicine To Concurrently Target Cancer Hallmarks for Combinatorial Therapy

Cancer hallmarks allow the complexity and heterogeneity of tumor biology to be better understood, leading to the discovery of various promising targets for cancer therapy. An amorphous iron oxide nanoparticle (NP)-based RNAi strategy is developed to co-target two cancer hallmarks. The NP technology can modulate the glycolysis pathway by silencing MCT4 to induce tumor cell acidosis, and concurrently exacerbate oxidative stress in tumor cells via the Fenton-like reaction. This strategy has the following features for systemic siRNA delivery: 1) siRNA encapsulation within NPs for improving systemic stability; 2) effective endosomal escape through osmotic pressure and/or endosomal membrane oxidation; 3) small size for enhancing tumor tissue penetration; and 4) triple functions (RNAi, Fenton-like reaction, and MRI) for combinatorial therapy and in vivo tracking.

Toxicity effects of AgZnO nanoparticles and rifampicin on Mycobacterium tuberculosis into the macrophage

The World Health Organization acknowledges tuberculosis as a global threat. Tuberculosis infection is one of the top 10 causes of death worldwide. Nanotechnology and microbiology researchers are looking for new and safe nano drugs for eliminating Mycobacterium tuberculosis, the causative agent of tuberculosis. In this study, AgZnO nano-crystals (AgZnONCs) is synthesized via the decomposition of the precursor of oxalate method. Characterization of AgZnONCs were evaluated. Next, various concentrations of AgZnONCs, as well AgZnONCs+Rifampicin, were prepared. The MTT assay was employed to study the viability of human macrophage cell lines (THP-1) exposed to AgZnONCs. The bactericidal effects of AgZnONCs and AgZnONCs+Rifampicin were studied by Minimum Bactericidal Concentration (MBC) test. Subsequently, THP-1 were infected by H₃₇ Rv strain of M. tuberculosis (H₃₇ RvMtb). Also, bactericidal effects of AgZnONCs and AgZnONCs+Rifampicin were compared with ex-vivo conditions. The MBC of AgZnONCs and AgZnONCs+Rifampicin were ratios of 1:4 and 1:32 respectively (p-value <0.05). Also, more than 50% and 80% of THP-1 were alive in ratios of 1:4 and 1:32 in the presence of AgZnONCs, respectively. All phagocytic H₃₇ RvMtb were killed in the presence of AgZnONCs+Rifampicin (p-value <0.05), while AgZnONCs were not able to kill all the H₃₇ RvMtb (p-value >0.05). This study showed that, AgZnONCs+Rifampicin has the most anti-tubercular behavior with respect to the macrophages.

Gold Nanorods as Drug Delivery Vehicles for Rifampicin Greatly Improve the Efficacy of Combating Mycobacterium tuberculosis with Good Biocompatibility with the Host Cells

TB remains a challenging disease to control worldwide. Nanoparticles have been used as drug carriers to deliver high concentrations of antibiotics directly to the site of infection, reducing the duration of treatment along with any side effects of off-target toxicities after systemic exposure to the antibiotics. Herein we have developed a drug delivery platform where gold nanorods (AuNRs) are conjugated to rifampicin (RF), which is released after uptake into macrophage cells (RAW264.7). Due to the nature of the macrophage cells, the nanoparticles are actively internalized into macrophages and release RF after uptake, under the safety frame of the host cells (macrophage). AuNRs without RF conjugation exhibit obvious antimicrobial activity. Therefore, AuNRs could be a promising antimycobacterial agent and an effective delivery vehicle for the antituberculosis drug Rifampicin for use in tuberculosis therapy.