Recent Developments in Drug Delivery for Treatment of Tuberculosis by Targeting Macrophages

Mannosamine-Modified Poly(lactic-co-glycolic acid)-Polyethylene Glycol Nanoparticles for the Targeted Delivery of Rifapentine and Isoniazid in Tuberculosis Therapy

Tuberculosis, caused by Mycobacterium tuberculosis, is the leading cause of mortality attributed to a single infectious agent. Following macrophage invasion, M. tuberculosis uses various mechanisms to evade immune responses and to resist antituberculosis drugs. This study aimed to develop a targeted drug delivery system utilizing mannosamine (MAN)-modified nanoparticles (NPs) composed of poly(lactic-co-glycolic acid)-polyethylene glycol (PLGA-PEG), loaded with rifapentine and isoniazid, to enhance macrophage-directed therapy and enhance bacterial elimination. PLGA-PEG copolymer was modified with mannosamine through an amidation reaction. Rifapentine- and isoniazid-loaded PLGA-PEG-MAN NPs were synthesized by using the double emulsion solvent evaporation technique. The NPs exhibited an average particle size of 117.67 nm and displayed favorable physicochemical properties without evidence of cellular or hemolytic toxicity. The drug loading rates were 11.73% for rifapentine and 5.85% for isoniazid. Sustained drug release was achieved over a period exceeding 72 h, with antibacterial activity remaining intact during encapsulation. Synergistic bactericidal effects were noted. Additionally, mannosamine-modified NPs enhanced the phagocytic activity of macrophages via mannose receptor-mediated endocytosis, thereby improving drug delivery efficiency and significantly boosting the antibacterial efficacy of the NPs within macrophages. Pathological staining and biochemical analysis of rat organs following intravenous injection indicated that the NPs did not cause any significant toxic side effects in vivo. The findings of this study indicate that mannosamine-modified PLGA-PEG NPs loaded with rifapentine and isoniazid represent a promising drug delivery system for targeting macrophages to enhance the efficacy of antitubercular therapy.

A review on biomacromolecular ligand-directed nanoparticles: New era in macrophage targeting

Traditional drug delivery strategies often have side effects due to uneven drug distribution leading to the subtherapeutic impacts. Ligand-modified nanoparticles offer a revolutionary approach to precise drug delivery. These modified nanoparticles can potentially target macrophages, which is crucial for defense and disease progression efficiently. Out of many classes of ligands, biomacromolecular ligands emerged as potential ligands for directing these nanoparticles to macrophages due to their consecutive receptors over the macrophage surface, assisting easy internalization and thus supporting elevated efficacy and reduced toxicity. This approach could significantly improve treatment for diseases like cancer, tuberculosis, etc. by directing drugs to macrophages and reducing side effects. By leveraging nanotechnology and biomacromolecular-based ligand-directed targeting, we can achieve more precise and effective treatments, paving the way for advancements in precision medicine.

3D spheroid model reveals enhanced efficacy of mannose-decorated nanoparticles for TB treatment

AIMS

Tuberculosis (TB), caused by Mycobacterium tuberculosis remains a significant global health challenge aggravated by drug-resistant strains and prolonged treatment regimens. Innovative strategies to enhance treatment efficacy, improve patient adherence, and reduce adverse effects are urgently required.

METHODS

We explored a combination therapy using bedaquiline and pretomanid encapsulated in polymeric nanoparticles (pNPs). Further, active targeting was achieved through mannose-decorated nanoparticles (Man-pNPs) for macrophage-specific delivery. The drug-loaded pNPs and Man-pNPs were spray-dried into dry powder particles to improve drug solubility and enable local lung delivery via inhalation. Man-pNPs were prepared to target macrophages, wherein TB bacteria reside.

RESULTS

Formulations exhibited high drug loading and excellent aerosolization performance (MMAD 1-5 µm, FPF > 75%) for pNPs and Man-pNPs. Man-pNPs formulation enhanced macrophage targeting via receptor-mediated endocytosis and phagocytosis, improving bacterial inhibition. Man-pNPs demonstrated similar MIC in vitro and enhanced intracellular M.tb inhibition compared to free drug combination and pNPs. In addition, a TB spheroid model was developed for formulation screening, mimicking granulomas' physiological conditions. Man-pNPs formulation showed superior intracellular bacterial inhibition in TB spheroid model compared to free drug combination and pNPs.

CONCLUSION

This research underscores the potential of combination therapy, particulate-based inhaled drug delivery, and active targeting to advance efficient and patient-friendly TB treatments.

Innovative Strategies for Combating Multidrug-Resistant Tuberculosis: Advances in Drug Delivery Systems and Treatment

Multidrug-resistant tuberculosis (MDR-TB) is a significant public health challenge globally, exacerbated by the limited efficacy of existing therapeutic approaches, prolonged treatment duration, and severe side effects. As drug resistance continues to emerge, innovative drug delivery systems and treatment strategies are critical to combating this crisis. This review highlights the molecular mechanisms underlying resistance to drugs in Mycobacterium tuberculosis, such as genetic mutation, efflux pump activity, and biofilm formation, contributing to the persistence and difficulty in eradicating MDR-TB. Current treatment options, including second-line drugs, offer limited effectiveness, prompting the need for innovation of advanced therapies and drug delivery systems. The progression in drug discovery has resulted in the approval of innovative therapeutics, including bedaquiline and delamanid, amongst other promising candidates under investigation. However, overcoming the limitations of traditional drug delivery remains a significant challenge. Nanotechnology has emerged as a promising solution, with nanoparticle-based drug delivery systems offering improved bioavailability and targeted and controlled release delivery, particularly for pulmonary targeting and intracellular delivery to macrophages. Furthermore, the development of inhalable formulations and the potential of nanomedicines to bypass drug resistance mechanisms presents a novel approach to enhancing drug efficacy. Moreover, adjunctive therapies, including immune modulation and host-directed therapies, are being explored to improve treatment outcomes. Immunotherapies, such as cytokine modulation and novel TB vaccines, offer complementary strategies to the use of antibiotics in combating MDR-TB. Personalized medicine approaches, leveraging genomic profiling of both the pathogen and the host, offer promise in optimizing treatment regimens and minimizing drug resistance. This review underscores the importance of multidisciplinary approaches, combining drug discovery, advanced delivery system development, and immune modulation to address the complexities of treating MDR-TB. Continued innovation, global collaboration, and improved diagnostics are essential to developing practical, accessible, and affordable treatments for MDR-TB.

Decoding drug resistance in Mycobacterium tuberculosis complex: genetic insights and future challenges

INTRODUCTION

Tuberculosis (TB), particularly its drug-resistant forms (MDR-TB and XDR-TB), continues to pose a significant global health challenge. Despite advances in treatment and diagnosis, the evolving nature of drug resistance in Mycobacterium tuberculosis (MTB) complicates TB eradication efforts. This review delves into the complexities of anti-TB drug resistance, its mechanisms, and implications on healthcare strategies globally.

AREAS COVERED

We explore the genetic underpinnings of resistance to both first-line and second-line anti-TB drugs, highlighting the role of mutations in key genes. The discussion extends to advanced diagnostic techniques, such as Whole-Genome Sequencing (WGS), CRISPR-based diagnostics and their impact on identifying and managing drug-resistant TB. Additionally, we discuss artificial intelligence applications, current treatment strategies, challenges in managing MDR-TB and XDR-TB, and the global disparities in TB treatment and control, translating to different therapeutic outcomes and have the potential to revolutionize our understanding and management of drug-resistant tuberculosis.

EXPERT OPINION

The current landscape of anti-TB drug resistance demands an integrated approach combining advanced diagnostics, novel therapeutic strategies, and global collaborative efforts. Future research should focus on understanding polygenic resistance and developing personalized medicine approaches. Policymakers must prioritize equitable access to diagnosis and treatment, enhancing TB control strategies, and support ongoing research and augmented government funding to address this critical public health issue effectively.

Navigating Perioperative Challenges in Pott's Spine: A Comprehensive Review

Pott's spine, or tuberculous spondylitis, remains a significant public health concern in regions where tuberculosis is endemic. The management of Pott's spine poses unique perioperative challenges due to the complexity of the disease process, including vertebral destruction, spinal instability, and neurological compromise. This comprehensive review explores the intricacies of navigating perioperative challenges in Pott's spine surgery. Beginning with an overview of Pott's spine, including its etiology, clinical presentation, and classification, the review delves into the significance of perioperative challenges in this condition. Emphasis is placed on the need for multidisciplinary collaboration, meticulous preoperative assessment, and tailored surgical planning to optimize outcomes while minimizing the risk of complications. Critical considerations in the preoperative, intraoperative, and postoperative phases of care are discussed in detail, including patient assessment, imaging modalities, surgical techniques, anesthesia considerations, and postoperative rehabilitation. Special considerations such as pediatric Pott's spine and multidrug-resistant tuberculosis are also addressed. The review concludes by summarizing key points, highlighting implications for clinical practice, and providing recommendations for future research. By synthesizing current evidence and clinical expertise, this review offers valuable insights into the optimal management of perioperative challenges in Pott's spine, ultimately aiming to improve patient outcomes and reduce the burden of this debilitating condition.

Conversion of liquid chitosan-based nanoemulsions into inhalable solid microparticles: Process challenges with polysaccharide

Solid particles ≤5 μm are essential to allow lower lung deposition and macrophage phagocytosis of anti-tubercular drugs. Decorating liquid nanoemulsion of anti-tubercular drug with macrophage-specific chitosan and chitosan-folate conjugate and spray drying the nanoemulsion with lactose produced oversized solid particles due to polysaccharide binding effects. This study designed solid nanoemulsion using lactose as the primary solid carrier and explored additives and spray-drying variables to reduce the binding and particle growth effects of chitosan. Deposition of magnesium stearate on lactose negated chitosan-inducible excessive lactose-liquid nanoemulsion binding and solid particle growth. Moderating the adhesion of chitosan-decorated liquid nanoemulsion onto lactose produced smooth-surface solid microparticles (size: 5.45 ± 0.26 μm; roughness: ∼80 nm) with heterogeneous size (span: 1.87 ± 1.21) through plasticization of constituent materials of nanoemulsion and lactose involving OH/N-H, C-H, CONH and/or COO moieties. Smaller solid particles could attach onto the larger particles with minimal steric hindrance by smooth surfaces. Together with round solid particulate structures (circularity: 0.919 ± 0.002), good pulmonary inhalation beneficial for treatment of pulmonary tuberculosis as well as other diseases is conferred.

Nano vs Resistant Tuberculosis: Taking the Lung Route

Tuberculosis (TB) is among the top 10 infectious diseases worldwide. It is categorized among the leading killer diseases that are the reason for the death of millions of people globally. Although a standardized treatment regimen is available, non-adherence to treatment has increased multi-drug resistance (MDR) and extensive drug-resistant (XDR) TB development. Another challenge is targeting the death of TB reservoirs in the alveoli via conventional treatment. TB Drug resistance may emerge as a futuristic restraint of TB with the scarcity of effective Anti-tubercular drugs. The paradigm change towards nano-targeted drug delivery systems is mostly due to the absence of effective therapy and increased TB infection recurrent episodes with MDR. The emerging field of nanotechnology gave an admirable opportunity to combat MDR and XDR via accurate diagnosis with effective treatment. The new strategies targeting the lung via the pulmonary route may overcome the new incidence of MDR and enhance patient compliance. Therefore, this review highlights the importance and recent research on pulmonary drug delivery with nanotechnology along with prevalence, the need for the development of nanotechnology, beneficial aspects of nanomedicine, safety concerns of nanocarriers, and clinical studies.

Biomimetic Systems Involving Macrophages and Their Potential for Targeted Drug Delivery

The concept of targeted drug delivery can be described in terms of the drug systems' ability to mimic the biological objects' property to localize to target cells or tissues. For example, drug delivery systems based on red blood cells or mimicking some of their useful features, such as long circulation in stealth mode, have been known for decades. On the contrary, therapeutic strategies based on macrophages have gained very limited attention until recently. Here, we review two biomimetic strategies associated with macrophages that can be used to develop new therapeutic modalities: first, the mimicry of certain types of macrophages (i.e., the use of macrophages, including tumor-associated or macrophage-derived particles as a carrier for the targeted delivery of therapeutic agents); second, the mimicry of ligands, naturally absorbed by macrophages (i.e., the use of therapeutic agents specifically targeted at macrophages). We discuss the potential applications of biomimetic systems involving macrophages for new advancements in the treatment of infections, inflammatory diseases, and cancer.

Advanced drug delivery and therapeutic strategies for tuberculosis treatment

Tuberculosis (TB) remains a significant global health challenge, necessitating innovative approaches for effective treatment. Conventional TB therapy encounters several limitations, including extended treatment duration, drug resistance, patient noncompliance, poor bioavailability, and suboptimal targeting. Advanced drug delivery strategies have emerged as a promising approach to address these challenges. They have the potential to enhance therapeutic outcomes and improve TB patient compliance by providing benefits such as multiple drug encapsulation, sustained release, targeted delivery, reduced dosing frequency, and minimal side effects. This review examines the current landscape of drug delivery strategies for effective TB management, specifically highlighting lipid nanoparticles, polymer nanoparticles, inorganic nanoparticles, emulsion-based systems, carbon nanotubes, graphene, and hydrogels as promising approaches. Furthermore, emerging therapeutic strategies like targeted therapy, long-acting therapeutics, extrapulmonary therapy, phototherapy, and immunotherapy are emphasized. The review also discusses the future trajectory and challenges of developing drug delivery systems for TB. In conclusion, nanomedicine has made substantial progress in addressing the challenges posed by conventional TB drugs. Moreover, by harnessing the unique targeting abilities, extended duration of action, and specificity of advanced therapeutics, innovative solutions are offered that have the potential to revolutionize TB therapy, thereby enhancing treatment outcomes and patient compliance.

Lipid Nanoparticles as Delivery Vehicles for Inhaled Therapeutics

Lipid nanoparticles (LNPs) have emerged as a powerful non-viral carrier for drug delivery. With the prevalence of respiratory diseases, particularly highlighted by the current COVID-19 pandemic, investigations into applying LNPs to deliver inhaled therapeutics directly to the lungs are underway. The progress in LNP development as well as the recent pre-clinical studies in three main classes of inhaled encapsulated drugs: small molecules, nucleic acids and proteins/peptides will be discussed. The advantages of the pulmonary drug delivery system such as reducing systemic toxicity and enabling higher local drug concentration in the lungs are evaluated together with the challenges and design considerations for improved formulations. This review provides a perspective on the future prospects of LNP-mediated delivery of inhaled therapeutics for respiratory diseases.