Nanotechnology-Based Approach in Tuberculosis Treatment

Antimicrobial peptides grafted onto the surface of N-acetylcysteine-chitosan nanoparticles can revitalize drugs against clinical isolates of Mycobacterium tuberculosis

Tuberculosis is caused by Mycobacterium tuberculosis (MTB) and is the leading cause of death from infectious diseases in the World. The search for new antituberculosis drugs is a high priority, since several drug-resistant TB-strains have emerged. Many nanotechnology strategies are being explored to repurpose or revive drugs. An interesting approach is to graft antimicrobial peptides (AMPs) to antibiotic-loaded nanoparticles. The objective of the present work was to determine the anti-MTB activity of rifampicin-loaded N-acetylcysteine-chitosan-based nanoparticles (NPs), conjugated with the AMP Ctx(Ile21)-Ha; against clinical isolates (multi- and extensively-drug resistant) and the H37Rv strain. The modified chitosan and drug-loaded NPs were characterized with respect to their physicochemical stability and their antimycobacterial profile, which showed potent inhibition (MIC values <0.977 μg/mL) by the latter. Furthermore, their accumulation within macrophages and cytotoxicity were determined. To understand the possible mechanisms of action, an in silico study of the peptide against MTB membrane receptors was performed. The results presented herein demonstrate that antibiotic-loaded NPs grafted with an AMP can be a powerful tool for revitalizing drugs against multidrug-resistant M. tuberculosis strains, by launching multiple attacks against MTB. This approach could potentially serve as a novel treatment strategy for various long-term diseases requiring extended treatment periods.

Micro-nanoemulsion and nanoparticle-assisted drug delivery against drug-resistant tuberculosis: recent developments

Tuberculosis (TB) is a major global health problem and the second most prevalent infectious killer after COVID-19. It is caused by Mycobacterium tuberculosis (Mtb) and has become increasingly challenging to treat due to drug resistance. The World Health Organization declared TB a global health emergency in 1993. Drug resistance in TB is driven by mutations in the bacterial genome that can be influenced by prolonged drug exposure and poor patient adherence. The development of drug-resistant forms of TB, such as multidrug resistant, extensively drug resistant, and totally drug resistant, poses significant therapeutic challenges. Researchers are exploring new drugs and novel drug delivery systems, such as nanotechnology-based therapies, to combat drug resistance. Nanodrug delivery offers targeted and precise drug delivery, improves treatment efficacy, and reduces adverse effects. Along with nanoscale drug delivery, a new generation of antibiotics with potent therapeutic efficacy, drug repurposing, and new treatment regimens (combinations) that can tackle the problem of drug resistance in a shorter duration could be promising therapies in clinical settings. However, the clinical translation of nanomedicines faces challenges such as safety, large-scale production, regulatory frameworks, and intellectual property issues. In this review, we present the current status, most recent findings, challenges, and limiting barriers to the use of emulsions and nanoparticles against drug-resistant TB.

Review of inhalable nanoparticles for the pulmonary delivery of anti-tuberculosis drugs

Tuberculosis is an airborne disease caused by the pathogen, Mycobacterium tuberculosis, which predominantly affects the lungs. World Health Organization (WHO) has reported that about 85% of TB patients are cured with the existing 6-month antibiotic regimen. However, the lengthy oral administration of high-dose anti-TB drugs is associated with significant side effects and leads to drug resistance cases. Alternatively, reformulating existing anti-tubercular drugs into inhalable nanoparticulate systems is a promising strategy to overcome the challenges associated with oral treatment as they could enhance drug retention in the pulmonary region to achieve an optimal drug concentration in the infected lungs. Hence, this review provides an overview of the literature on inhalable nano-formulations for the delivery of anti-TB drugs, including their formulation techniques and preclinical evaluations between the years 2000 and 2020, gathered from electronic journals via online search engines such as Google Scholar and PubMed. Previous in vitro and in vivo studies highlighted that the nano-size, low toxicity, and high efficacy were among the factors influencing the fate of nanoparticulate system upon deposition in the lungs. Although many preclinical studies have shown that inhalable nanoparticles increased therapeutic efficacy and minimised adverse drug reactions when delivered through the pulmonary route, none of them has progressed into clinical trials to date. This could be attributed to the high cost of inhaled regimes due to the expensive production and characterisation of the nanoparticles as well as the need for an inhalation device as compared to the oral treatment. Another barrier could be the lack of medical acceptance due to insufficient number of trained staff to educate the patients on the correct usage of the inhalation device. Hence, these barriers should be addressed satisfactorily to make the inhaled nanoparticles regimen a reality for the treatment of TB.

Overcoming Mycobacterium tuberculosis Drug Resistance: Novel Medications and Repositioning Strategies

Mycobacterium tuberculosis, the bacterium responsible for tuberculosis, is a global health concern, affecting millions worldwide. This bacterium has earned a reputation as a formidable adversary due to its multidrug-resistant nature, allowing it to withstand many antibiotics. The development of this drug resistance in Mycobacterium tuberculosis is attributed to innate and acquired mechanisms. In the past, rifampin was considered a potent medication for treating tuberculosis infections. However, the rapid development of resistance to this drug by the bacterium underscores the pressing need for new therapeutic agents. Fortunately, several other medications previously overlooked for tuberculosis treatment are already available in the market. Moreover, several innovative drugs are under clinical investigation, offering hope for more effective treatments. To enhance the effectiveness of these drugs, it is recommended that researchers concentrate on identifying unique target sites within the bacterium during the drug development process. This strategy could potentially circumvent the issues presented by Mycobacterium drug resistance. This review primarily focuses on the characteristics of novel drug resistance mechanisms in Mycobacterium tuberculosis. It also discusses potential medications being repositioned or sourced from novel origins. The ultimate objective of this review is to discover efficacious treatments for tuberculosis that can successfully tackle the hurdles posed by Mycobacterium drug resistance.

[Potential use of liposomes in tuberculosis treatment]

Tuberculosis is among the infectious diseases with the highest mortality and morbidity worldwide, behind the COVID-19 pandemic. It can affect any organ, although the respiratory infection is the most common. The correct activation of the immune response eliminates or contain the bacteria; however, the active disease is progressive and must be treated under strict supervision. Treatment for tuberculosis is prolonged and consists of a combination of several antibiotics associated with a wide variety of adverse effects. These effects are the main cause of therapeutic abandonment, which facilitates the appearance of drug-resistant strains. Hence the importance of developing new therapeutic strategies to reduce the dose of the drug or its administration time. To achieve these objectives, the use of nano-vehicles, which are controlled and directed drug release systems, has been proposed. Specifically, liposomes are formulations that have advantages when administered by the respiratory route since they facilitate the reach of the respiratory mucosa and the lungs, which are the main organs affected by tuberculosis. This review analyzes the use of nano-vehicles as effective drug delivery systems and the formulations under study. Perspectives for the application of nanotechnology in the development of new pharmacological treatments for tuberculosis are also proposed.

Evolution of tuberculosis diagnostics: From molecular strategies to nanodiagnostics

Tuberculosis has remained a global concern for public health affecting the lives of people for ages. Approximately 10 million people are affected by the disease and 1.5 million succumb to the disease worldwide annually. The COVID-19 pandemic has highlighted the role of early diagnosis to win the battle against such infectious diseases. Thus, advancement in the diagnostic approaches to provide early detection forms the foundation to eradicate and manage contagious diseases like tuberculosis. The conventional diagnostic strategies include microscopic examination, chest X-ray and tuberculin skin test. The limitations associated with sensitivity and specificity of these tests demands for exploring new techniques like probe-based assays, CRISPR-Cas and microRNA detection. The aim of the current review is to envisage the correlation between both the conventional and the newer approaches to enhance the specificity and sensitivity. A significant emphasis has been placed upon nanodiagnostic approaches manipulating quantum dots, magnetic nanoparticles, and biosensors for accurate diagnosis of latent, active and drug-resistant TB. Additionally, we would like to ponder upon a reliable method that is cost-effective, reproducible, require minimal infrastructure and provide point-of-care to the patients.

Innovative Therapeutic Approaches Based on Nanotechnology for the Treatment and Management of Tuberculosis

Tuberculosis (TB), derived from bacterium named Mycobacterium tuberculosis, has become one of the worst infectious and contagious illnesses in the world after HIV/AIDS. Long-term therapy, a high pill burden, lack of compliance, and strict management regimens are disadvantages which resulted in the extensively drug-resistant (XDR) along with multidrug-resistant (MDR) in the treatment of TB. One of the main thrust areas for the current scenario is the development of innovative intervention tools for early diagnosis and therapeutics towards Mycobacterium tuberculosis (MTB). This review discusses various nanotherapeutic agents that have been developed for MTB diagnostics, anti-TB drugs and vaccine. Undoubtedly, the concept of employing nanoparticles (NPs) has strong potential in this therapy and offers impressive outcomes to conquer the disease. Nanocarriers with different types were designed for drug delivery applications via various administration methods. Controlling and maintaining the drug release might be an example of the benefits of utilizing a drug-loaded NP in TB therapy over conventional drug therapy. Furthermore, the drug-encapsulated NP is able to lessen dosage regimen and can resolve the problems of insufficient compliance. Over the past decade, NPs were developed in both diagnostic and therapeutic methods, while on the other hand, the therapeutic system has increased. These "theranostic" NPs were designed for nuclear imaging, optical imaging, ultrasound, imaging with magnetic resonance and the computed tomography, which includes both single-photon computed tomography and positron emission tomography. More specifically, the current manuscript focuses on the status of therapeutic and diagnostic approaches in the treatment of TB.

Impact of nanoparticles on amyloid β-induced Alzheimer's disease, tuberculosis, leprosy and cancer: a systematic review

Nanotechnology is an interdisciplinary domain of science, technology and engineering that deals with nano-sized materials/particles. Usually, the size of nanoparticles lies between 1 and 100 nm. Due to their small size and large surface area-to-volume ratio, nanoparticles exhibit high reactivity, greater stability and adsorption capacity. These important physicochemical properties attract scientific community to utilize them in biomedical field. Various types of nanoparticles (inorganic and organic) have broad applications in medical field ranging from imaging to gene therapy. These are also effective drug carriers. In recent times, nanoparticles are utilized to circumvent different treatment limitations. For example, the ability of nanoparticles to cross the blood-brain barrier and having a certain degree of specificity towards amyloid deposits makes themselves important candidates for the treatment of Alzheimer's disease. Furthermore, nanotechnology has been used extensively to overcome several pertinent issues like drug-resistance phenomenon, side effects of conventional drugs and targeted drug delivery issue in leprosy, tuberculosis and cancer. Thus, in this review, the application of different nanoparticles for the treatment of these four important diseases (Alzheimer's disease, tuberculosis, leprosy and cancer) as well as for the effective delivery of drugs used in these diseases has been presented systematically. Although nanoformulations have many advantages over traditional therapeutics for treating these diseases, nanotoxicity is a major concern that has been discussed subsequently. Lastly, we have presented the promising future prospective of nanoparticles as alternative therapeutics. In that section, we have discussed about the futuristic approach(es) that could provide promising candidate(s) for the treatment of these four diseases.

Spotlight on mycobacterial lipid exploitation using nanotechnology for diagnosis, vaccines, and treatments

Tuberculosis (TB), historically the most significant cause of human morbidity and mortality, has returned as the top infectious disease worldwide, under circumstances worsened by the COVID-19 pandemic's devastating effects on public health. Although Mycobacterium tuberculosis, the causal agent, has been known of for more than a century, the development of tools to control it has been largely neglected. With the advancement of nanotechnology, the possibility of engineering tools at the nanoscale creates unique opportunities to exploit any molecular type. However, little attention has been paid to one of the major attributes of the pathogen, represented by the atypical coat and its abundant lipids. In this review, an overview of the lipids encountered in M. tuberculosis and interest in exploiting them for the development of TB control tools are presented. Then, the amalgamation of nanotechnology with mycobacterial lipids from both reported and future works are discussed.

Nano-Delivery System of Ethanolic Extract of Propolis Targeting Mycobacterium tuberculosis via Aptamer-Modified-Niosomes

Tuberculosis (TB) therapy requires long-course multidrug regimens leading to the emergence of drug-resistant TB and increased public health burden worldwide. As the treatment strategy is more challenging, seeking a potent non-antibiotic agent has been raised. Propolis serve as a natural source of bioactive molecules. It has been evidenced to eliminate various microbial pathogens including Mycobacterium tuberculosis (Mtb). In this study, we fabricated the niosome-based drug delivery platform for ethanolic extract of propolis (EEP) using thin film hydration method with Ag85A aptamer surface modification (Apt-PEGNio/EEP) to target Mtb. Physicochemical characterization of PEGNio/EEP indicated approximately -20 mV of zeta potential, 180 nm of spherical nanoparticles, 80% of entrapment efficiency, and the sustained release profile. The Apt-PEGNio/EEP and PEGNio/EEP showed no difference in these characteristics. The chemical composition in the nanostructure was confirmed by Fourier transform infrared spectrometry. Apt-PEGNio/EEP showed specific binding to Mycobacterium expressing Ag85 membrane-bound protein by confocal laser scanning microscope. It strongly inhibited Mtb in vitro and exhibited non-toxicity on alveolar macrophages. These findings indicate that the Apt-PEGNio/EEP acts as an antimycobacterial nanoparticle and might be a promising innovative targeted treatment. Further application of this smart nano-delivery system will lead to effective TB management.

Immunomodulation in age-related disorders and nanotechnology interventions

Recently, the aging population has increased exponentially around the globe bringing more challenges to improve quality of life in those populations while reducing the economic burden on healthcare systems. Aging is associated with changes in the immune system culminating in detrimental effects such as immune dysfunction, immunosenescence, and chronic inflammation. Age-related decline of immune functions is associated with various pathologies including cardiovascular, autoimmune, neurodegenerative, and infectious diseases to name a few. Conventional treatment addresses the onset of age-related diseases by early detection of risk factors, administration of vaccines as preventive care, immunomodulatory treatment, and other dietary supplements. However, these approaches often come with systemic side-effects, low bioavailability of therapeutic agents, and poor outcomes seen in the elderly. Recent innovations in nanotechnology have led to the development of novel biomaterials/nanomaterials, which explore targeted drug delivery and immunomodulatory interactions in vivo. Current nanotechnology-based immunomodulatory approaches that have the potential to be used as therapeutic interventions for some prominent age-related diseases are discussed here. Finally, we explore challenges and future aspects of nanotechnology in the treatments of age-related disorders to improve quality of life in the elderly. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Antimicrobial resistance: new insights and therapeutic implications

Antimicrobial resistance has not been a new phenomenon. Still, the number of resistant organisms, the geographic areas affected by emerging drug resistance, and the magnitude of resistance in a single organism are enormous and mounting. Disease and disease-causing agents formerly thought to be contained by antibiotics are now returning in new forms resistant to existing therapies. Antimicrobial resistance is one of the most severe and complicated health issues globally, driven by interrelated dynamics in humans, animals, and environmental health sectors. Coupled with various epidemiological factors and a limited pipeline for new antimicrobials, all these misappropriations allow the transmission of drug-resistant organisms. The problem is likely to worsen soon. Antimicrobial resistance in general and antibiotic resistance in particular is a shared global problem. Actions taken by any single country can adversely or positively affect the other country. Targeted coordination and prevention strategies are critical in stopping the spread of antibiotic-resistant organisms and hence its overall management. This article has provided in-depth knowledge about various methods that can help mitigate the emergence and spread of antimicrobial resistance globally. KEY POINTS: • Overview of antimicrobial resistance as a global challenge and explain various reasons for its rapid progression. • Brief about the intrinsic and acquired resistance to antimicrobials and development of antibiotic resistance in bacteria. • Systematically organized information is provided on different strategies for tackling antimicrobial resistance for the welfare of human health.

Recent advances in vitamin D implications in chronic respiratory diseases

Chronic airway inflammatory and infectious respiratory diseases are the most common medical respiratory conditions, associated with significant morbidity and mortality. Vitamin D (1,25(OH)₂D₃) deficiency has been shown to be highly prevalent in patients with chronic airway inflammatory and infectious diseases, correlated with increased disease severity. It has been established that vitamin D modulates ongoing abnormal immune responses in chronic respiratory diseases and is shown to restrict bacterial and viral colonization into the lungs. On the contrary, other studies revealed controversy findings regarding vitamin D efficacy in respiratory diseases. This review aims to update the current evidence regarding the role of vitamin D in airway inflammation and in various respiratory diseases. A comprehensive search of the last five years of literature was conducted using MEDLINE and non-MEDLINE PubMed databases, Ovid MEDLINE, SCOPUS-Elsevier, and data from in vitro and in vivo experiments, including clinical studies. This review highlights the importance of understanding the full range of implications that vitamin D may have on lung inflammation, infection, and disease severity in the context of chronic respiratory diseases.

Nanoparticle-Based Inhalation Therapy for Pulmonary Diseases

The lung is exposed to various pollutants and is the primary site for the onset of various diseases, including infections, allergies, and cancers. One possible treatment approach for such pulmonary diseases involves direct administration of therapeutics to the lung so as to maintain the topical concentration of the drug. Particles with nanoscale diameters tend to reach the pulmonary region. Nanoparticles (NPs) have garnered significant interest for applications in biomedical and pharmaceutical industries because of their unique physicochemical properties and biological activities. In this article, we describe the biological and pharmacological activities of NPs as well as summarize their potential in the formulation of drugs employed to treat pulmonary diseases. Recent advances in the use of NPs in inhalation chemotherapy for the treatment of lung diseases have also been highlighted.

Tuberculosis drug discovery: Progression and future interventions in the wake of emerging resistance

The emergence of drug resistance continues to afflict TB control where drug resistant strains have become a global health concern. Contrary to drug-sensitive TB, the treatment of MDR/XDR-TB is more complicated requiring the administration of second-line drugs that are inefficient than the first line drugs and are associated with greater side effects. The emergence of drug resistant Mtb strains had coincided with an innovation void in the field of drug discovery of anti-mycobacterials. However, the approval of bedaquiline and delamanid recently for use in MDR/XDR-TB has given an impetus to the TB drug discovery. The review discusses the drug discovery efforts in the field of tuberculosis with a focus on the strategies adopted and challenges confronted by TB research community. Here, we discuss the diverse clinical candidates in the current TB drug discovery pipeline. There is an urgent need to combat the current TB menace through multidisciplinary approaches and strategies making use of the recent advances in understanding the molecular biology and pathogenesis of Mtb. The review highlights the recent advances in drug discovery, with the host directed therapeutics and nanoparticles-drug delivery coming up as important tools to fight tuberculosis in the future.

2Receptor Specific Ligand conjugated Nanocarriers: an Effective Strategy for Targeted Therapy of Tuberculosis

Tuberculosis (TB) is an ancient chronic disease caused by the bacillus Mycobacterium tuberculosis, which has affected mankind for more than 4,000 years. Compliance with the standard conventional treatment can assure recovery from tuberculosis, but emergence of drug resistant strains pose a great challenge for effective management of tuberculosis. The process of discovery and development of new therapeutic entities with better specificity and efficacy is unpredictable and time consuming. Hence, delivery of pre-existing drugs with improved targetability is the need of the hour. Enhanced delivery and targetability can ascertain improved bioavailability, reduced toxicity, decreased frequency of dosing and therefore better patient compliance. Nanoformulations are being explored for effective delivery of therapeutic agents, however optimum specificity is not guaranteed. In order to achieve specificity, ligands specific to receptors or cellular components of macrophage and Mycobacteria can be conjugatedto nanocarriers. This approach can improve localization of existing drug molecules at the intramacrophageal site where the parasites reside, improve targeting to the unique cell wall structure of Mycobacterium or improve adhesion to epithelial surface of intestine or alveolar tissue (lectins). Present review focuses on the investigation of various ligands like Mannose, Mycolic acid, Lectin, Aptamers etc. installed nanocarriers that are being envisaged for targeting antitubercular drugs.

Alginate-Capped Silver Nanoparticles as a Potent Anti-mycobacterial Agent Against Mycobacterium tuberculosis

Tuberculosis (TB) is a leading cause of death from a single infectious agent, Mycobacterium tuberculosis (Mtb). Although progress has been made in TB control, still about 10 million people worldwide develop TB annually and 1.5 million die of the disease. The rapid emergence of aggressive, drug-resistant strains and latent infections have caused TB to remain a global health challenge. TB treatments are lengthy and their side effects lead to poor patient compliance, which in turn has contributed to the drug resistance and exacerbated the TB epidemic. The relatively low output of newly approved antibiotics has spurred research interest toward alternative antibacterial molecules such as silver nanoparticles (AgNPs). In the present study, we use the natural biopolymer alginate to serve as a stabilizer and/or reductant to green synthesize AgNPs, which improves their biocompatibility and avoids the use of toxic chemicals. The average size of the alginate-capped AgNPs (ALG-AgNPs) was characterized as nanoscale, and the particles were round in shape. Drug susceptibility tests showed that these ALG-AgNPs are effective against both drug-resistant Mtb strains and dormant Mtb. A bacterial cell-wall permeability assay showed that the anti-mycobacterial action of ALG-AgNPs is mediated through an increase in cell-wall permeability. Notably, the anti-mycobacterial potential of ALG-AgNPs was effective in both zebrafish and mouse TB animal models in vivo. These results suggest that ALG-AgNPs could provide a new therapeutic option to overcome the difficulties of current TB treatments.

Commercial utilities and future perspective of nanomedicines

The present review aims to describe the commercial utilities and future perspectives of nanomedicines. Nanomedicines are intended to increase precision medicine and decrease the adverse effects on the patient. Nanomedicines are produced, engineered, and industrialized at the cellular, chemical, and macromolecular levels. This study describes the various aspects of nanomedicine such as governing outlooks over high use of nanomedicine, regulatory advancements for nanomedicines, standards, and guidelines for nanomedicines as per Therapeutic Goods Administration (TGA). This review also focuses on the patents and clinical trials based on nanoformulation, along with nanomedicines utilization as drug therapy and their market value. The present study concludes that nanomedicines are of high importance in biomedical and pharmaceutical production and offer better therapeutic effects especially in the case of drugs that possess low aqueous solubility. The factual data presented in this study will assist the researchers and health care professionals in understanding the applications of nanomedicine for better diagnosis and effective treatment of a disease.

Novel mesoporous silica nanocarriers containing gold; a rapid diagnostic tool for tuberculosis

Tuberculosis (TB) is major health concern and reason of deaths from decades to current date. Even though with a lot of advancements, diagnostic techniques, and discovery of standard antibiotics TB remains crucial challenge and can create worst scenario for human health in near future. Nanoparticles play emerging role in diagnosis and treatment of TB. In this study, we developed mesoporous silica nanoparticles containing gold (MSNs@GNPs) for rapid diagnosis and treatment of TB. The physicochemical characterization revealed effective surface morphology and particles diameter, that is applicable for in vitro applications. The in vitro antimicrobial analysis revealed that the designed MSNs@GNPs has retained significantly lower minimal inhibitory concentration (MIC) values and can effectively demolish mycobacterium tuberculosis (Mtb). Furthermore, the diagnosis efficiency of the MSNs@GNPs was evaluated by calorimetric analysis. Which demonstrates that MSNs@GNPs can be used for rapid diagnosis of the tuberculosis when applied on in vitro culture of the Mtb. The current study needs further verification on human's clinical samples from tuberculosis patients. However, MSNs@GNPs can be a versatile clinical approach for the rapid diagnosis and clinical treatment of the tuberculosis.

Micro/nanotechnology-inspired rapid diagnosis of respiratory infectious diseases

Humans have suffered from a variety of infectious diseases since a long time ago, and now a new infectious disease called COVID-19 is prevalent worldwide. The ongoing COVID-19 pandemic has led to research of the effective methods of diagnosing respiratory infectious diseases, which are important to reduce infection rate and help the spread of diseases be controlled. The onset of COVID-19 has led to the further development of existing diagnostic methods such as polymerase chain reaction, reverse transcription polymerase chain reaction, and loop-mediated isothermal amplification. Furthermore, this has contributed to the further development of micro/nanotechnology-based diagnostic methods, which have advantages of high-throughput testing, effectiveness in terms of cost and space, and portability compared to conventional diagnosis methods. Micro/nanotechnology-based diagnostic methods can be largely classified into (1) nanomaterials-based, (2) micromaterials-based, and (3) micro/nanodevice-based. This review paper describes how micro/nanotechnologies have been exploited to diagnose respiratory infectious diseases in each section. The research and development of micro/nanotechnology-based diagnostics should be further explored and advanced as new infectious diseases continue to emerge. Only a handful of micro/nanotechnology-based diagnostic methods has been commercialized so far and there still are opportunities to explore.

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.

Applications of Nanoparticles for Herpes Simplex Virus (HSV) and Human Immunodeficiency Virus (HIV) Treatment

In recent years, the growing studies focused on the immunotherapy of hepatocellular carcinoma and proved the preclinical and clinical promises of host antitumor immune response. However, there were still various obstacles in meeting satisfactory clinic need, such as low response rate, primary resistance and secondary resistance to immunotherapy. Tackling these barriers required a deeper understanding of immune underpinnings and a broader understanding of advanced technology. This review described immune microenvironment of liver and HCC which naturally decided the complexity of immunotherapy, and summarized recent immunotherapy focusing on different points. The ever-growing clues indicated that the instant killing of tumor cell and the subsequent relive of immunosuppressive microenvironment were both indis- pensables. The nanotechnology applied in immunotherapy and the combination with intervention technology was also discussed.

Tuberculosis: An Overview of the Immunogenic Response, Disease Progression, and Medicinal Chemistry Efforts in the Last Decade toward the Development of Potential Drugs for Extensively Drug-Resistant Tuberculosis Strains

Tuberculosis (TB) is a slow growing, potentially debilitating disease that has plagued humanity for centuries and has claimed numerous lives across the globe. Concerted efforts by researchers have culminated in the development of various strategies to combat this malady. This review aims to raise awareness of the rapidly increasing incidences of multidrug-resistant (MDR) and extensively drug-resistant (XDR) tuberculosis, highlighting the significant modifications that were introduced in the TB treatment regimen over the past decade. A description of the role of pathogen-host immune mechanisms together with strategies for prevention of the disease is discussed. The struggle to develop novel drug therapies has continued in an effort to reduce the treatment duration, improve patient compliance and outcomes, and circumvent TB resistance mechanisms. Herein, we give an overview of the extensive medicinal chemistry efforts made during the past decade toward the discovery of new chemotypes, which are potentially active against TB-resistant strains.

Development of lipid nanocarriers for tuberculosis treatment: evaluation of suitable excipients and nanocarriers

BACKGROUND

Lipid nanocarriers have been widely tested as drug delivery systems to treat diseases due to their bioavailability, controlled release, and low toxicity. For the pulmonary route, the Food and Drug Administration favors the use of substances generally recognized as safe, as well as biodegradable and biocompatible to minimize the possibility of toxicity. Tuberculosis (TB) remains a public health threat worldwide, mainly due to the long treatment duration and adverse effects. Therefore, new drug delivery systems to treat TB are needed.

OBJECTIVE

Physicochemical characterization of different lipid-based nanocarriers was used to optimize carrier properties. Optimized systems were incubated with Mycobacterium tuberculosis to assess whether lipid-based systems act as an energy source for the bacteria, which could be counterproductive to therapy.

METHOD

Several excipients and surfactants were evaluated to prepare different types of nanocarriers using high-pressure homogenization.

RESULTS

A mixture of trimyristin with castor oil was chosen as the lipid matrix after differential scanning calorimetry analysis. A mixture of egg lecithin and PEG-660 stearate was selected as an optimal surfactant system as this mixture formed the most stable formulations. Three types of lipid nanocarriers, solid lipid nanoparticles, nanostructured lipid carriers (NLC), and Nano emulsions, were prepared, with the NLC systems showing the most suitable properties for further evaluation. It may provide the advantages of increasing the entrapment efficiency, drug release, and the ability to be lyophilized, producing powder for pulmonary administration being an alternative to entrap poor water-soluble molecules.

CONCLUSION

Furthermore, the NLC system can be considered for use as a platform for the treatment of TB by the pulmonary route.

Molecular mechanisms of underlying genetic factors and associated mutations for drug resistance in Mycobacterium tuberculosis

Nowadays, drug-resistant tuberculosis (DR-TB) and co-infected tuberculosis (CI-TB) strains are the leading cause for the enhancement of long-term morbidity and unpredicted mortality rates from this ghoulish acid fast-bacterium infection, globally. Unfortunately, the lack of/ample lethargic towards the development of compelling anti-TB regimens with a large-scale prevalence rate is a great challenge towards control of the pandemic situation. Indeed, the recent improvement in genomic studies for early diagnosis and understanding the mechanisms of drug resistance, as well as the identification of newer drug targets is quite remarkable and promising. Mainly, identification of such genetic factors, chromosomal mutations and associated pathways gives new ray of hope in current anti-TB drug discovery. This focused review provides molecular insights into the updated drug resistance mechanisms with encoded bacilli genetic factors as a novel target and potential source of development with screened-out newer anti-TB agents towards the control of MDR-TB soon.

The Macrophage Response to Mycobacterium tuberculosis and Opportunities for Autophagy Inducing Nanomedicines for Tuberculosis Therapy

The major causative agent of tuberculosis (TB), i.e., Mycobacterium tuberculosis (Mtb), has developed mechanisms to evade host defense responses and persist within host cells for prolonged periods of time. Mtb is also increasingly resistant to existing anti-TB drugs. There is therefore an urgent need to develop new therapeutics for TB and host directed therapies (HDTs) hold potential as effective therapeutics for TB. There is growing interest in the induction of autophagy in Mtb host cells using autophagy inducing compounds (AICs). Nanoparticles (NPs) can enhance the effect of AICs, thus improving stability, enabling cell targeting and providing opportunities for multimodal therapy. In this review, we focus on the macrophage responses to Mtb infection, in particular, the mechanistic aspects of autophagy and the evasion of autophagy by intracellular Mtb. Due to the overlap between the onset of autophagy and apoptosis; we also focus on the relationship between apoptosis and autophagy. We will also review known AICs in the context of Mtb infection. Finally, we discuss the applications of NPs in inducing autophagy with the intention of sharing insights to encourage further research and development of nanomedicine HDTs for TB therapy.

Recent applications and strategies in nanotechnology for lung diseases

Lung diseases, including COVID-19 and lung cancers, is a huge threat to human health. However, for the treatment and diagnosis of various lung diseases, such as pneumonia, asthma, cancer, and pulmonary tuberculosis, are becoming increasingly challenging. Currently, several types of treatments and/or diagnostic methods are used to treat lung diseases; however, the occurrence of adverse reactions to chemotherapy, drug-resistant bacteria, side effects that can be significantly toxic, and poor drug delivery necessitates the development of more promising treatments. Nanotechnology, as an emerging technology, has been extensively studied in medicine. Several studies have shown that nano-delivery systems can significantly enhance the targeting of drug delivery. When compared to traditional delivery methods, several nanoparticle delivery strategies are used to improve the detection methods and drug treatment efficacy. Transporting nanoparticles to the lungs, loading appropriate therapeutic drugs, and the incorporation of intelligent functions to overcome various lung barriers have broad prospects as they can aid in locating target tissues and can enhance the therapeutic effect while minimizing systemic side effects. In addition, as a new and highly contagious respiratory infection disease, COVID-19 is spreading worldwide. However, there is no specific drug for COVID-19. Clinical trials are being conducted in several countries to develop antiviral drugs or vaccines. In recent years, nanotechnology has provided a feasible platform for improving the diagnosis and treatment of diseases, nanotechnology-based strategies may have broad prospects in the diagnosis and treatment of COVID-19. This article reviews the latest developments in nanotechnology drug delivery strategies in the lungs in recent years and studies the clinical application value of nanomedicine in the drug delivery strategy pertaining to the lung.

Approaches to treating tuberculosis by encapsulating metal ions and anti-mycobacterial drugs utilizing nano- and microparticle technologies

Tuberculosis (TB) is caused by a bacterial infection that affects a number of human organs, primarily the lungs, but also the liver, spleen, and spine, causing key symptoms of fever, fatigue, and persistent cough, and if not treated properly, can be fatal. Every year, 10 million individuals become ill with active TB resulting with a mortality approximating 1.5 million. Current treatment guidelines recommend oral administration of a combination of first-line anti-TB drugs for at least 6 months. While efficacious under optimum conditions, 'Directly Observed Therapy Short-course' (DOTS) is not without problems. The long treatment time and poor pharmacokinetics, alongside drug side effects lead to poor patient compliance and has accelerated the emergence of multi-drug resistant (MDR) organisms. All this, combined with the limited number of newly discovered TB drugs to treat MDR-TB and shorten standard therapy time, has highlighted the need for new targeted drug delivery systems. In this respect, there has been recent focus on micro- and nano-particle technologies to prepare organic or/and metal particles loaded with TB drugs to enhance their efficacy by targeted delivery via the inhaled route. In this review, we provide a brief overview of the current epidemiology of TB, and risk factors for progression of latent stage tuberculosis (LTBI) to the active TB. We identify current TB treatment regimens, newly discovered TB drugs, and identify studies that have used micro- or nano-particles technologies to design a reliable inhalation drug delivery system to treat TB more effectively.

Mycogenic Metal Nanoparticles for the Treatment of Mycobacterioses

Mycobacterial infections are a resurgent and increasingly relevant problem. Within these, tuberculosis (TB) is particularly worrying as it is one of the top ten causes of death in the world and is the infectious disease that causes the highest number of deaths. A further concern is the on-going emergence of antimicrobial resistance, which seriously limits treatment. The COVID-19 pandemic has worsened current circumstances and future infections will be more incident. It is urgent to plan, draw solutions, and act to mitigate these issues, namely by exploring new approaches. The aims of this review are to showcase the extensive research and application of silver nanoparticles (AgNPs) and other metal nanoparticles (MNPs) as antimicrobial agents. We highlight the advantages of mycogenic synthesis, and report on their underexplored potential as agents in the fight against all mycobacterioses (non-tuberculous mycobacterial infections as well as TB). We propose further exploration of this field.

DNA flowerstructure co-localizes with human pathogens in infected macrophages

Herein, we characterize the cellular uptake of a DNA structure generated by rolling circle DNA amplification. The structure, termed nanoflower, was fluorescently labeled by incorporation of ATTO488-dUTP allowing the intracellular localization to be followed. The nanoflower had a hydrodynamic diameter of approximately 300 nanometer and was non-toxic for all mammalian cell lines tested. It was internalized specifically by mammalian macrophages by phagocytosis within a few hours resulting in specific compartmentalization in phagolysosomes. Maximum uptake was observed after eight hours and the nanoflower remained stable in the phagolysosomes with a half-life of 12 h. Interestingly, the nanoflower co-localized with both Mycobacterium tuberculosis and Leishmania infantum within infected macrophages although these pathogens escape lysosomal degradation by affecting the phagocytotic pathway in very different manners. These results suggest an intriguing and overlooked potential application of DNA structures in targeted treatment of infectious diseases such as tuberculosis and leishmaniasis that are caused by pathogens that escape the human immune system by modifying macrophage biology.

Isoniazid-phytochemical conjugation: A new approach for potent and less toxic anti-TB drug development

Mycobacterium tuberculosis (Mtb) causes one of the most grievous pandemic infectious diseases, tuberculosis (TB), with long-term morbidity and high mortality. The emergence of drug-resistant Mtb strains, and the co-infection with human immunodeficiency virus, challenges the current WHO-TB stewardship programs. The first-line anti-TB drugs, isoniazid (INH) and rifampicin (RIF), have become extensively obsolete in TB control from chromosomal mutations during the last decades. However, based on clinical trial statistics, the production of well-tolerated anti-TB drug(s) is miserably low. Alternately, semi-synthesis or structural modifications of first-line obsolete antitubercular drugs remain as the versatile approach for getting some potential medicines. The use of any suitable phytochemicals with INH in a hybrid formulation could be an ideal approach for the development of potent anti-TB drug(s). The primary objective of this review was to highlight and analyze available INH-phytochemical hybrid research works. The utilization of phytochemicals through chemical conjugation is a new trend toward the development of safer/non-toxic anti-TB drugs.

Silver Nanoparticles for the Therapy of Tuberculosis

Rapid emergence of aggressive, multidrug-resistant Mycobacteria strain represents the main cause of the current antimycobacterial-drug crisis and status of tuberculosis (TB) as a major global health problem. The relatively low-output of newly approved antibiotics contributes to the current orientation of research towards alternative antibacterial molecules such as advanced materials. Nanotechnology and nanoparticle research offers several exciting new-concepts and strategies which may prove to be valuable tools in improving the TB therapy. A new paradigm in antituberculous therapy using silver nanoparticles has the potential to overcome the medical limitations imposed in TB treatment by the drug resistance which is commonly reported for most of the current organic antibiotics. There is no doubt that AgNPs are promising future therapeutics for the medication of mycobacterial-induced diseases but the viability of this complementary strategy depends on overcoming several critical therapeutic issues as, poor delivery, variable intramacrophagic antimycobacterial efficiency, and residual toxicity. In this paper, we provide an overview of the pathology of mycobacterial-induced diseases, andhighlight the advantages and limitations of silver nanoparticles (AgNPs) in TB treatment.

Multi-functionalized nanocarriers targeting bacterial reservoirs to overcome challenges of multi drug-resistance

INTRODUCTION

Infectious diseases associated with intracellular bacteria such as Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis are important public health concern. Emergence of multi and extensively drug-resistant bacterial strains have made it even more obstinate to offset such infections. Bacteria residing within intracellular compartments provide additional barriers to effective treatment.

METHOD

Information provided in this review has been collected by accessing various electronic databases including Google scholar, Web of science, Scopus, and Nature index. Search was performed using keywords nanoparticles, intracellular targeting, multidrug resistance, Staphylococcus aureus; Salmonella typhimurium; Mycobacterium tuberculosis. Information gathered was categorized into three major sections as 'Intracellular targeting of Staphylococcus aureus, Intracellular targeting of Salmonella typhimurium and Intracellular targeting of Mycobacterium tuberculosis' using variety of nanocarrier systems.

RESULTS

Conventional management for infectious diseases typically comprises of long-term treatment with a combination of antibiotics, which may lead to side effects and decreased patient compliance. A wide range of multi-functionalized nanocarrier systems have been studied for delivery of drugs within cellular compartments where bacteria including Staphylococcus aureus, Salmonella typhimurium and Mycobacterium tuberculosis reside. Such carrier systems along with targeted delivery have been utilized for sustained and controlled delivery of drugs. These strategies have been found useful in overcoming the drawbacks of conventional treatments including multi-drug resistance.

CONCLUSION

Development of multi-functional nanocargoes encapsulating antibiotics that are proficient in targeting and releasing drug into infected reservoirs seems to be a promising strategy to circumvent the challenge of multidrug resistance. Graphical abstract.

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.

Diagnosis of Tuberculosis: Nanodiagnostics Approaches

Tuberculosis (TB) remains one of the most devastating infectious diseases worldwide. The burden of TB is alarmingly high in developing countries, where diagnosis latent TB infection (LTBI), Extra-pulmonary tuberculosis (EPTB), drug-resistant tuberculosis (DR-TB), HIV-associated TB, and paediatric TB is still a challenge. This is mainly due to delayed or misdiagnosis of TB, which continues to fuel its worldwide epidemic. The ideal diagnostic test is still unavailable, and conventional methods remain a necessity for TB diagnosis, though with poor diagnostic ability. The nanoparticles have shown potential for the improvement of drug delivery, reducing treatment frequency and diagnosis of various diseases. The engineering of antigens/antibody nanocarriers represents an exciting front in the field of diagnostics, potentially flagging the way toward development of better diagnostics for TB. This chapter discusses the presently available tests for TB diagnostics and also highlights the recent advancement in the nanotechnology-based detection tests for M. tuberculosis.

Merged experimental guided computational strategy toward tuberculosis treatment mediated by alveolar macrophages mannose receptor

Macrophage mannose receptor (MMR) is a C-type lectin that regulates the phagocytosis and phagocytosis-lysosome (P-L) fusion in tuberculosis. Mannose-capped lipoarabinomannan, a lipoglycan present at the surface of Mycobacterium tuberculosis, is an important factor in phagocyte attachment and internalization that is specific for MMR. Based on this idea, herein we have designed our experiment to understand the better site-specific delivery against tuberculosis. An experimental outcome was used as a basis to revisit the reverse experimental strategy for tuberculosis management. Stearic mannose was prepared from stearic acid incubation with the D-mannose. Interestingly, stearic mannose explained its internalization via stimulating actin-mediated phagocytic pathway of MMR experimentally. Following, an in silico strategy towards hypothetical designing of various mannose-stearyl conjugates (SBKK1-7) against tuberculosis, as binding promoter of MMR (PDB: 1EGI), was carried out using molecular docking and dynamics approaches. Overall, SPKK-5 viz. ortho stearic mannose showed a higher binding affinity with notable H-bonding and hydrophobic interactions. Pharmacokinetic and toxicity examinations illustrated an ideal range of descriptors values for apex screened compounds. Molecular dynamics simulations have confirmed its significant intactness with the MMR. Ultimately, the whole effort led to the identification of promising hit (SBKK-5), which positively correlates with the experimental work and furthermore need to explore its novel drug delivery systems with improved anti-tubercular therapy.Communicated by Ramaswamy H. Sarma.

Recent updates on drug resistance in Mycobacterium tuberculosis

Tuberculosis (TB) along with acquired immune deficiency syndrome and malaria rank among the top three fatal infectious diseases which pose threat to global public health, especially in middle and low income countries. TB caused by Mycobacterium tuberculosis (Mtb) is an airborne infectious disease and one-third of the world's population gets infected with TB leading to nearly 1·6 million deaths annually. TB drugs are administered in different combinations of four first-line drugs (rifampicin, isoniazid, pyrazinamide and ethambutol) which form the core of treatment regimens in the initial treatment phase of 6-9 months. Several reasons account for the failure of TB therapy such as (i) late diagnosis, (ii) lack of timely and proper administration of effective drugs, (iii) lower availability of less toxic, inexpensive and effective drugs, (iv) long treatment duration, (v) nonadherence to drug regimen and (vi) evolution of drug-resistant TB strains. Drug-resistant TB poses a significant challenge to TB therapy and control programs. In the background of worldwide emergence of 558 000 new TB cases with resistance to rifampicin in the year 2017 and of them, 82% becoming multidrug-resistant TB (MDR-TB), it is essential to continuously update the knowledge on the mechanisms and molecular basis for evolution of Mtb drug resistance. This narrative and traditional review summarizes the progress on the anti-tubercular agents, their mode of action and drug resistance mechanisms in Mtb. The aim of this review is to provide recent updates on drug resistance mechanisms, newly developed/repurposed anti-TB agents in pipeline and international recommendations to manage MDR-TB. It is based on recent literature and WHO guidelines and aims to facilitate better understanding of drug resistance for effective TB therapy and clinical management.

Nanotechnology based therapeutics for lung disease

Nanomedicine is a multidisciplinary research field with an integration of traditional sciences such as chemistry, physics, biology and materials science. The application of nanomedicine for lung diseases as a relatively new area of interdisciplinary science has grown rapidly over the last 10 years. Promising research outcomes suggest that nanomedicine will revolutionise the practice of medicine, through the development of new approaches in therapeutic agent delivery, vaccine development and nanotechnology-based medical detections. Nano-based approaches in the diagnosis and treatment of lung diseases will, in the not too distant future, change the way we practise medicine. This review will focus on the current trends and developments in the clinical translation of nanomedicine for lung diseases, such as in the areas of lung cancer, cystic fibrosis, asthma, bacterial infections and COPD.

Pulmonary surfactant and drug delivery: Focusing on the role of surfactant proteins

Pulmonary surfactant (PS) has been extensively studied because of its primary role in mammalian breathing. The deposition of this surface-active material at the alveolar air-water interface is essential to lower surface tension, thus avoiding alveolar collapse during expiration. In addition, PS is involved in host defense, facilitating the clearance of potentially harmful particulates. PS has a unique composition, including 92% of lipids and 8% of surfactant proteins (SPs) by mass. Although they constitute the minor fraction, SPs to a large extent orchestrate PS-related functions. PS contains four surfactant proteins (SPs) that can be structurally and functionally divided in two groups, i.e. the large hydrophilic SP-A and SP-D and the smaller hydrophobic SP-B and SP-C. The former belong to the family of collectins and are involved in opsonization processes, thus promoting uptake of pathogens and (nano)particles by phagocytic cell types. The latter SPs regulate interfacial surfactant adsorption dynamics, facilitating (phospho)lipid transfer and membrane fusion processes. In the context of pulmonary drug delivery, the exploitation of PS as a carrier to promote drug spreading along the alveolar interface is gaining interest. In addition, recent studies investigated the interaction of PS with drug-loaded nanoparticles (nanomedicines) following pulmonary administration, which strongly influences their biological fate, drug delivery efficiency and toxicological profile. Interestingly, the specific biophysical mode-of-action of the four SPs affect the drug delivery process of nanomedicines both on the extra-and intracellular level, modulating pulmonary distribution, cell targeting and intracellular delivery. This knowledge can be harnessed to exploit SPs for the design of unique and bio-inspired drug delivery strategies.

Cure of tuberculosis using nanotechnology: An overview

Mycobacterium tuberculosis is the causative agent of tuberculosis (TB), a major health issue of the present era. The bacterium inhabits the host macrophage and other immune cells where it modulates the lysosome trafficking protein, hinders the formation of phagolysosome, and blocks the TNF receptor-dependent apoptosis of host macrophage/monocytes. Other limitations such as resistance to and low bioavailability and bio-distribution of conventional drugs aid to their high virulence and human mortality. This review highlights the use of nanotechnology-based approaches for drug formulation and delivery which could open new avenues to limit the pathogenicity of tuberculosis. Moreover phytochemicals, such as alkaloids, phenols, saponins, steroids, tannins, and terpenoids, extracted from terrestrial plants and mangroves seem promising against M. tuberculosis through different molecular mechanisms. Further understanding of the genomics and proteomics of this pathogenic microbe could also help overcome various research gaps in the path of developing a suitable therapy against tuberculosis.