Gelatin nanocarriers as potential vectors for effective management of tuberculosis

Drug delivery strategies for local immunomodulation in transplantation: Bridging the translational gap

Drug delivery strategies for local immunomodulation hold tremendous promise compared to current clinical gold-standard systemic immunosuppression as they could improve the benefit to risk ratio of life-saving or life-enhancing transplants. Such strategies have facilitated prolonged graft survival in animal models at lower drug doses while minimizing off-target effects. Despite the promising outcomes in preclinical animal studies, progression of these strategies to clinical trials has faced challenges. A comprehensive understanding of the translational barriers is a critical first step towards clinical validation of effective immunomodulatory drug delivery protocols proven for safety and tolerability in pre-clinical animal models. This review overviews the current state-of-the-art in local immunomodulatory strategies for transplantation and outlines the key challenges hindering their clinical translation.

Pharmaceutical Applications of Biomass Polymers: Review of Current Research and Perspectives

Polymers derived from natural biomass have emerged as a valuable resource in the field of biomedicine due to their versatility. Polysaccharides, peptides, proteins, and lignin have demonstrated promising results in various applications, including drug delivery design. However, several challenges need to be addressed to realize the full potential of these polymers. The current paper provides a comprehensive overview of the latest research and perspectives in this area, with a particular focus on developing effective methods and efficient drug delivery systems. This review aims to offer insights into the opportunities and challenges associated with the use of natural polymers in biomedicine and to provide a roadmap for future research in this field.

Enhancing antimicrobial activity and reducing cytotoxicity of silver nanoparticles through gelatin nanoparticles

Aim: To develop a novel stabilizing agent for silver nanoparticles (AgNPs) with the aim of enhancing its antibacterial efficacy against wound associated pathogens while mitigating their cytotoxic effect on human cells. Materials & methods: In this study, monodispersed gelatin nanoparticles were synthesized to stabilize AgNPs. The stability, antibacterial activity and biocompatibility of the gelatin-stabilized AgNPs (Gel-AgNPs) were compared with citrate-stabilized AgNPs (citrate-AgNPs) or silver ions. Results & conclusion: Gelatin-stabilized AgNPs showed significantly better antibacterial activities compared with citrate-stabilized AgNPs against both Gram-positive and Gram-negative bacteria. These Gel-AgNPs showed significantly lower cytotoxicity to human dermal fibroblasts compared with Ag+. These findings provided the first evidence substantiating a novel functionality of gelatin nanoparticles in both stabilizing and enhancing the activity of AgNPs.

Degradable Polymeric Bio(nano)materials and Their Biomedical Applications: A Comprehensive Overview and Recent Updates

Degradable polymers (both biomacromolecules and several synthetic polymers) for biomedical applications have been promising very much in the recent past due to their low cost, biocompatibility, flexibility, and minimal side effects. Here, we present an overview with updated information on natural and synthetic degradable polymers where a brief account on different polysaccharides, proteins, and synthetic polymers viz. polyesters/polyamino acids/polyanhydrides/polyphosphazenes/polyurethanes relevant to biomedical applications has been provided. The various approaches for the transformation of these polymers by physical/chemical means viz. cross-linking, as polyblends, nanocomposites/hybrid composites, interpenetrating complexes, interpolymer/polyion complexes, functionalization, polymer conjugates, and block and graft copolymers, are described. The degradation mechanism, drug loading profiles, and toxicological aspects of polymeric nanoparticles formed are also defined. Biomedical applications of these degradable polymer-based biomaterials in and as wound dressing/healing, biosensors, drug delivery systems, tissue engineering, and regenerative medicine, etc., are highlighted. In addition, the use of such nano systems to solve current drug delivery problems is briefly reviewed.

Human Serum Albumin Nanoparticles: Synthesis, Optimization and Immobilization with Antituberculosis Drugs

The aim of this study was to create nanoparticles of human serum albumin immobilized with anti-TB drugs (rifampicin, isoniazid) using the desolvation method. Central Composite Design (CCD) was applied to study the effect of albumin, urea, L-cysteine, rifampicin and isoniazid concentration on particle size, polydispersity and loading degree of the drugs. The optimized nanoparticles were spherical in shape with an average particle size of 216.7 ± 3.7 nm and polydispersity of 0.286 ± 4.9. The loading degree of rifampicin and isoniazid in the optimized nanoparticles were 44% and 27%, respectively. The obtained nanoparticles were examined by Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC); the results showed the absence of drug-polymer interactions. The drug release from the polymer matrix was studied using dialysis membranes.

Biopolymer-Based Nanogel Approach in Drug Delivery: Basic Concept and Current Developments

Due to their increased surface area, extent of swelling and active substance-loading capacity and flexibility, nanogels made from natural and synthetic polymers have gained significant interest in scientific and industrial areas. In particular, the customized design and implementation of nontoxic, biocompatible, and biodegradable micro/nano carriers makes their usage very feasible for a range of biomedical applications, including drug delivery, tissue engineering, and bioimaging. The design and application methodologies of nanogels are outlined in this review. Additionally, the most recent advancements in nanogel biomedical applications are discussed, with particular emphasis on applications for the delivery of drugs and biomolecules.

An Insight into Advances in Developing Nanotechnology Based Therapeutics, Drug Delivery, Diagnostics and Vaccines: Multidimensional Applications in Tuberculosis Disease Management

Tuberculosis (TB), one of the deadliest contagious diseases, is a major concern worldwide. Long-term treatment, a high pill burden, limited compliance, and strict administration schedules are all variables that contribute to the development of MDR and XDR tuberculosis patients. The rise of multidrug-resistant strains and a scarcity of anti-TB medications pose a threat to TB control in the future. As a result, a strong and effective system is required to overcome technological limitations and improve the efficacy of therapeutic medications, which is still a huge problem for pharmacological technology. Nanotechnology offers an interesting opportunity for accurate identification of mycobacterial strains and improved medication treatment possibilities for tuberculosis. Nano medicine in tuberculosis is an emerging research field that provides the possibility of efficient medication delivery using nanoparticles and a decrease in drug dosages and adverse effects to boost patient compliance with therapy and recovery. Due to their fascinating characteristics, this strategy is useful in overcoming the abnormalities associated with traditional therapy and leads to some optimization of the therapeutic impact. It also decreases the dosing frequency and eliminates the problem of low compliance. To develop modern diagnosis techniques, upgraded treatment, and possible prevention of tuberculosis, the nanoparticle-based tests have demonstrated considerable advances. The literature search was conducted using Scopus, PubMed, Google Scholar, and Elsevier databases only. This article examines the possibility of employing nanotechnology for TB diagnosis, nanotechnology-based medicine delivery systems, and prevention for the successful elimination of TB illnesses.

Current nanotechnological strategies using lipids, carbohydrates, proteins and metal conjugates-based carrier systems for diagnosis and treatment of tuberculosis - A review

Tuberculosis is a fatal disease caused by Mycobacterium tuberculosis with highest morbidity and mortality every year. The evolution of anti-TB drugs is promising in controlling and treating TB. Yet, the drug response varies depending on the bacterial load and host immunological profiles. The prolonged anti-TB treatment regimen and high pill burden leads to poor adherence to treatment and acquired drug resistance. In the clinical arena, sustainable nanotechnology improves the targeted strategies leading to enhance therapeutic recovery with minimum treatment duration and virtuous drug adherence. Determinants of nanosystems are the size, nature, formulation techniques, stable dosing patterns, bioavailability and toxicity. In the treatment of chronic illness, nanomedicines inclusive of biological macromolecules such as lipids, peptides, and nucleic acids occur to be a successive alternative to synthetic carriers. Most biological nanomaterials possess antimicrobial properties with other intrinsic characteristics. Recently, the pulmonary delivery of anti-TB drugs through polymeric nanocarrier systems is shown to be effective in achieving optimal drug levels in lungs for longer duration, enhanced tissue permeation and sustained systemic clearance. This thematic review provides a holistic insight into the nanodelivery systems pertinent to the therapeutic applications in pulmonary tuberculosis describing the choice of carriers, optimized process, metabolic action and excretion processes.

Polymeric Nanocomposite Hydrogel Scaffolds in Craniofacial Bone Regeneration: A Comprehensive Review

Nanocomposite biomaterials combine a biopolymeric matrix structure with nanoscale fillers. These bioactive and easily resorbable nanocomposites have been broadly divided into three groups, namely natural, synthetic or composite, based on the polymeric origin. Preparing such nanocomposite structures in the form of hydrogels can create a three-dimensional natural hydrophilic atmosphere pivotal for cell survival and new tissue formation. Thus, hydrogel-based cell distribution and drug administration have evolved as possible options for bone tissue engineering and regeneration. In this context, nanogels or nanohydrogels, created by cross-linking three-dimensional polymer networks, either physically or chemically, with high biocompatibility and mechanical properties were introduced as promising drug delivery systems. The present review highlights the potential of hydrogels and nanopolymers in the field of craniofacial tissue engineering and bone regeneration.

Enhancement of Antimycobacterial Activity of Rifampicin Using Mannose-Anchored Lipid Nanoparticles against Intramacrophage Mycobacteria

Tuberculosis treatment requires a multidrug combination for the long-term, associated with adverse effects which lead to nonpatient compliance and the emergence of drug-resistant strains. Thus, mannose-anchored rifampicin-loaded solid lipid nanoparticles (M-RIF-SLNs) were developed to enhance the effect of rifampicin by selectively delivering to the macrophage, which led to the high intracellular killing of mycobacteria. The synthesized M-RIF-SLNs show a particle size of ∼100 nm and a drug loading of ∼8%. Cytotoxicity assay confirms that M-RIF-SLNs are not toxic up to 16 μg/mL (equivalent to incorporated rifampicin in SLN) toward THP-1-differentiated macrophages. An antimicrobial assay exhibits a reduction of minimum inhibitory concentration by 4-fold and 8-fold against wild-type and laboratory drug-resistant strains of M. smegmatis, respectively, compared to free rifampicin. Furthermore, mannose-functionalized SLNs loaded with coumarin-6 exhibit a higher macrophage uptake than that of unfunctionalized SLNs. Finally, higher intramacrophage clearance of M. tuberculosis H37Ra was observed with M-RIF-SLNs compared to RIF-SLNs and free rifampicin. Hence, the overall results support that the developed M-RIF-SLNs can be a promising approach for improving the antibacterial activity of rifampicin against intracellular mycobacteria residing in the alveolar macrophages.

Changing paradigms in the treatment of tuberculosis

Tuberculosis, caused by Mycobacterium tuberculosis, is a disease long dealt with, but still remains the second leading cause of death world-wide. The current anti-tubercular chemotherapy primarily targets the microbial pathogenesis, which however, is failing due to the development of drug resistance. Moreover, with fewer new drugs reaching the market, there is a need to focus on alternate treatment approaches that could be used as stand-alone or adjunct therapy and the existing drugs, referred to as Track II chemotherapy. This article is an attempt to review the changing global patterns of tuberculosis and its treatment. Further, newer drug delivery approaches like multi-particulate drug carriers which increase the therapeutic efficacy and bring down the systemic toxicity associated with drugs have also been discussed. There is also a need to use interventions which can be used as Track II therapy. Host-directed therapeutics (HDT) is an emerging area concept in which host cell functions and hence the response to pathogens can be modulated, which can help manage TB. HDT decreases damage induced due to inflammation and necrosis in the lungs and other parts of the body due to the disease. Various immuno-modulatory pathways have been discussed in this review which could be explored further to treat TB. An in-depth understanding of multi-particulate drug carriers and HDT could help in dealing with tuberculosis; however, there is still a long way to go.

Nanohydrogels: Advanced Polymeric Nanomaterials in the Era of Nanotechnology for Robust Functionalization and Cumulative Applications

In the era of nanotechnology, the synthesis of nanomaterials for advanced applications has grown enormously. Effective therapeutics and functionalization of effective drugs using nano-vehicles are considered highly productive and selectively necessary. Polymeric nanomaterials have shown their impact and influential role in this process. Polymeric nanomaterials in molecular science are well facilitated due to their low cytotoxic behavior, robust functionalization, and practical approach towards in vitro and in vivo therapeutics. This review highlights a brief discussion on recent techniques used in nanohydrogel designs, biomedical applications, and the applied role of nanohydrogels in the construction of advanced therapeutics. We reviewed recent studies on nanohydrogels for their wide applications in building strategies for advantageously controlled biological applications. The classification of polymers is based on their sources of origin. Nanohydrogel studies are based on their polymeric types and their endorsed utilization for reported applications. Nanotechnology has developed significantly in the past decades. The novel and active role of nano biomaterials with amplified aspects are consistently being studied to minimize the deleterious practices and side effects. Here, we put forth challenges and discuss the outlook regarding the role of nanohydrogels, with future perspectives on delivering constructive strategies and overcoming the critical objectives in nanotherapeutic systems.

Polymeric nanoparticles as therapeutic agents against coronavirus disease

Nanotechnology has the potential to improve the combat against life-threatening conditions. Considering the COVID-19 scenario, and future outbreaks, nanotechnology can play a pivotal role in several steps, ranging from disinfection protocols, manufacture of hospital clothes, to implementation of healthcare settings. Polymeric nanoparticles are colloidal particles with size ranging from 10 to 999 nm, composed of natural or synthetic polymers. The versatility of polymeric-based nanoparticle engineering can provide (i) specificity, (ii) tunable release kinetics, and (iii) multimodal drug composition, making it possible to overcome common limitations encountered during traditional drug development. Consequently, these particles have been widely used as drug delivery systems against several diseases, such as cancer. Due to inherent competitive advantages, polymeric-based nanoparticles hold astonishing potential to counteract the new coronavirus disease (COVID-19). For this reason, in the present study, the latest advancements in polymer-based nanotechnology approaches used to fight against SARS-CoV-2 are compiled and discussed. Moreover, the importance of forefront in vitro technologies - such as 3D bioprinting and organ-on-chip - to evaluate the efficacy of nanotherapeutic agents is also highlighted. Polymeric nanoparticles can be functionalized to enhance its potential as a nanotherapeutic agent. Due to its many advantages, polymeric-based nanoparticles systems are a promising approach against coronavirus disease 2019 (COVID-19).

A Freezing and Thawing Method for Fabrication of Small Gelatin Nanoparticles with Stable Size Distributions for Biomedical Applications

BACKGROUND

Gelatin, a natural polymer, has a number of advantages as a material for fabricating nanoparticles, such as its hydrophilicity, biodegradability, nontoxicity, and biocompatibility, as well as low cost. Despite these various advantages, gelatin-based nanoparticles still have critical limitation for biomedical applications due to their relatively larger size than those of other materials.

METHODS

In this study, a new strategy to design and fabricate small gelatin nanoparticles (GNPs) was proposed. The technique was based on the natural phenomenon where with decreasing temperature, the compression between the molecules of substances increases and the volume shrinks.

RESULTS

The average size of the fabricated small GNPs was less than 100 nm and their gelatin properties (including non-cytotoxicity) were well maintained. The drug release profiles of the GNPs were confirmed, for which a simple mathematical model based on the conventional diffusion equation was proposed. There was a burst of drug release in the first 3 days, with different release profiles according to the concentration of model drugs loaded onto the GNPs. It was also demonstrated that the drug release profiles of the proposed mathematical model were consistent with the experimental results.

CONCLUSION

Our work proposes that these small GNPs could be used as efficient drug and gene delivery and tissue engineering platforms for various biomedical applications.

Challenges and Opportunities of Nanotechnological based Approach for the Treatment of Tuberculosis

Mycobacterium tuberculosis, because of its unique biochemical behavior and a complex host relationship, successfully evades the host immune system. Therefore, chemotherapy appears to be the first-line option for patients with tuberculosis. However, poor patient compliance with anti-tubercular treatment and variability in anti-tubercular drug pharmacokinetics are among the major driving factors for the emergence of drug resistance. The rising cases of extrapulmonary TB, cross-resistance patterns, high prevalence of tuberculosis and HIV co-infections make tuberculosis treatment more complicated than conventional multidrug therapy. Due to their distinct advantages like higher solubility, increased payload, controlled release profiles, tissue-specific accumulation, and lack of toxicity, nanoscale materials have immense potential for drug delivery applications. An appropriate selection of polymer and careful particle engineering further improves therapeutic outcomes with opportunities to overcome conventional anti-tubercular drugs' challenges. The present review introduces the prospect of using nanotechnology in tuberculosis (TB) chemotherapy and provides a comprehensive overview of recent advances in nanocarriers implied for delivering anti-tubercular drugs.

Polyethylene imine conjugated supramolecular stereocomplexed nanomicelles for intracellular delivery of rifampicin against Mycobacterium bovis

The main objective of this study was to investigate polyethylene imine (PEI) based stereocomplexed nanomiceles for intracellular delivery of rifampicin against Mycobacterium bovis (M. bovis) and their in vitro-in vivo evaluation. The formation of Rifampicin (Rif) loaded isotactic (PEI-g-PLLA and PEI-g-PDLA) and stereocomplexed nanomicelles (StM) of PEI conjugated poly l- and poly d-lactic acid via self-assembly was thoroughly explored. Synthesis of polymer graft was confirmed via FTIR and NMR. A 2-fold reduction in CMC of StM was observed along with decreased particle size in comparison to isotactic nanomicelles. In vitro, StM exhibited a higher encapsulation efficiency and 84 % of drug release in 48 h. at pH 5 with minimal initial burst release in comparison to isotactic nanomicelles. Minimum inhibitory concentration (MIC) of StM was found to be four folds lower in contrast to isotactic nanomicelles. Ex vivo studies exhibited a better uptake of StM and minimum cytotoxicity in murine alveolar macrophages. Following oral administration in mice, drug loaded StM exhibited highest distribution in macrophage rich organs, longer half-life, AUC, AUMC and MRT in comparison to isotactic nanomicelles indicating maximum bioavailability and efficacy of StM. In vivo antimycobacterial activity also demonstrated a higher reduction (2.38fold) in M. bovis CFU at reduced dosing frequency by drug loaded StM in comparison to control group. Thus, StM can be regarded as a simple, stable, efficient, and biocompatible carrier system for delivery of rifampicin to intracellular M. bovis with added advantage of reduced dosing frequency and improved patient compliance.

Fabrication and Characterization of Surface Engineered Rifampicin Loaded Lipid Nanoparticulate Systems for the Potential Treatment of Tuberculosis: An In Vitro and In Vivo Evaluation

The main aim of the present investigation highlights the development of mannose appended rifampicin containing solid lipid nanoparticles (Mn-RIF-SLNs) for the management of pulmonary TB. The developed Mn-RIF-SLNs showed particle size of Mn-RIF-SLNs (479 ± 13 nm) which was found to be greater than that of unconjugated SLNs (456 ± 11 nm), with marginal reduction in percentage entrapment efficiency (79.41 ± 2.42%). The in vitro dissolution studies depicted an initial burst release followed by sustained release profile indicating biphasic release pattern, close-fitting Weibull model having least F-value. The cytotoxicity studies using J774A.1 cell line represented that the developed SLNs were non-toxic and safe as compared to free drug. Fluorescence imaging and flow cytometric (FACS) analysis depicted significant (1.79-folds) intracellular uptake of coumarin-6 (fluorescent marker) loaded Mn-C6-SLNs. The in vivo pharmacokinetic studies in sprague-dawley rats were performed and Mn-RIF-SLNs showed remarkable enhancement in terms of relative bioavailability (~17-folds) as compared to its drug solution via oral administration. The biodistribution studies revealed higher lung accumulation (1.8-folds) of Mn-RIF-SLNs as compared to the Un-RIF-SLNs. In conclusion, the developed Mn-RIF-SLNs could serve as a promising tool for delivering the drug cargo to the site of infection (lungs) in the treatment of TB.

Self-Assembled chitosan/phospholipid nanoparticles: from fundamentals to preparation for advanced drug delivery

With the development of nanotechnology, self-assembled chitosan/phospholipid nanoparticles (SACPNs) show great promise in a broad range of applications, including therapy, diagnosis, in suit imaging and on-demand drug delivery. Here, a brief review of the SACPNs is presented, and its critical underlying formation mechanisms are interpreted with an emphasis on the intrinsic physicochemical properties. The state-of-art preparation methods of SACPNs are summarized, with particular descriptions about the classic solvent injection method. Then SACPNs microstructures are characterized, revealing the unique spherical core-shell structure and the drug release mechanisms. Afterwards, a comprehensive and in-depth depiction of their emerging applications, with special attention to drug delivery areas, are categorized and reviewed. Finally, conclusions and outlooks on further advancing the SACPNs toward a more powerful and versatile platform for investigations covering from fundamental understanding to developing multi-functional drug delivery systems are discussed.

Development of Rifapentine-Loaded PLGA-Based Nanoparticles: In vitro Characterisation and in vivo Study in Mice

Background

Tuberculosis (TB) is a leading cause of death amongst infectious diseases. The poor response to antitubercular agents necessitates the long-term use of high drug doses, resulting in low patient compliance, which is the main reason for chemotherapy failure and contributes to the development of multidrug-resistant TB. Patient non-compliance has been a major obstacle in the successful management of TB. The aim of this work was to develop and characterise rifapentine (RPT)-loaded PLGA-based nanoparticles (NPs) for reducing dosing frequency.

Methods

RPT-loaded PLGA and PLGA–PEG NPs were prepared using premix membrane homogenisation combined with solvent evaporation method. The resulting NPs were characterised in terms of physicochemical characteristics, toxicity, cellular uptake and antitubercular activity. NPs were further evaluated for pharmacokinetic and biodistribution studies in mice.

Results

The resulting NPs showed suitable and safe physicochemical characteristics and could be taken up by macrophages. RPT-loaded NPs were more effective against Mycobacterium tuberculosis than free RPT. In vivo studies revealed that NPs could improve pharmacokinetic parameters, particularly for RPT/PLGA–PEG NPs. Moreover, both formulations had no toxicity to the organs of mice and could reduce hepatotoxicity.

Conclusion

The application of PLGA-based NPs as sustained-release delivery vehicles for RPT could prolong drug release, modify pharmacokinetics, increase antitubercular activity and diminish toxicity, thereby allowing low dosage and frequency.

Controlling Particle Size and Release Kinetics in the Sustained Delivery of Oral Antibiotics Using pH-Independent Mucoadhesive Polymers

Copolymers synthesized from acrylic acid and methacrylic acid used as gastroprotective and mucoadhesive enteric coatings have been used to prepare micro- (∼2 μm), submicro- (∼200 nm), and nanoparticles (∼20 nm) containing rifampicin (Rif) to obtain time-controlled drug release kinetics. Different particle sizes and drug release kinetics have been obtained using different synthesis conditions and fabrication techniques including the use of an electrosprayer and an interdigital microfabricated micromixer. The antimicrobial action of the encapsulated Rif has been demonstrated against Staphylococcus aureus ATCC 25923 and compared with the effect of the equivalent dose of the free macrolide antibiotic. At low concentrations, the encapsulated antibiotic showed superior antimicrobial activity than the free drug. The stability of the developed particles has been evaluated in vitro under simulated gastric and intestinal conditions. At the concentrations tested, a reduced cytotoxicity against different human cell lines was observed after analyzing their subcytotoxic doses and the influence on their cell cycle by flow cytometry. Drug release kinetics can be tuned by adjusting particle sizes, and it would be possible to reach the minimum inhibitory concentration or the minimum bactericidal concentration at different time points depending on the medical needs.

Gelatin nanoparticles for NSAID systemic administration: Quality by design and artificial neural networks implementation

The present study evaluates the preparation of systemic administrated NSAID gelatin nanoparticles with the aid of quality by design and artificial neural networks (ANNs). Specifically, two different preparation techniques (i.e. nanoprecipitation and two-step desolvation) were implemented for the formulation of diclofenac sodium (DLC) gelatin nanoparticles (GNs). Preliminary screening experiments showed that in the case of nanoprecipitation the best compromise (in terms of achieving both small particle size and high encapsulation efficiency) was the use of poloxamer 407 (as stabilizer) and acetone (as non-solvent), while in the case of two-step desolvation significant effect had the use of acetone, gelatin type and bloom number (type B with bloom 150 was selected for further evaluation). Implementation of a central composite experimental design (CCD), showed that in the case of nanoprecipitation the optimum formulation can be achieved at high poloxamer, high gelatin and moderate to high glutaraldehyde (GTA used for crosslinking) concentrations, while in the case of two-step desolvation high gelatin and GTA concentrations are needed. Artificial neural networks (ANN) implementation showed significantly improved prediction ability compared to MLR, while verification experiments showed good agreement between the ANN predicted and the experimentally obtained results. SEM analysis of the optimum suggested formulations showed nanoparticles with smooth surface, while powder X-ray diffraction (XRD) analysis showed the formation of amorphously dispersed systems, and Fourier transform infrared spectroscopy (FTIR) revealed the presence of molecular interactions irrespectively of the preparation method followed. A slightly faster release profile was observed in the case of nanoprecipitation based GNs, while all formulations followed biphasic release profile.

Carbon nanomaterials: a new way against tuberculosis

Introduction: Tuberculosis (TB) remains one of the most alarming worldwide infectious diseases primarily in low-income countries, where the infection shows a higher and unvaried prevalence. In the last years, the emergence and spread of Mycobacterium tuberculosis (Mtb) strains resistant to first-line anti-TB drugs are the cause of major concern and prompted the implementation of new treatments, including the development of new drugs and the repurposing of old ones. Areas covered: In this review, we discuss solutions against TB based on nanomaterials (NMTs), alone or combined with current anti-TB drugs. We will summarize drug delivery platforms tested in in vivo or in vitro models and their activity against mycobacteria. We will describe how the new nanotechnologies based on carbon nanomaterials, like carbon nanotubes and graphene oxide are now facing the panorama of the medical fight against TB. Expert opinion: We foresee that in the next decade carbon nanomaterials will be at the forefront in fighting emerging antibiotic-resistant Mtb strains by shortening treatment periods, reducing adverse effects and mitigating antibiotic use. However, toxicity and biodegradation studies should be done prior to the clinical translation of carbon nanomaterials.

Pharmacokinetic, toxicokinetic, and bioavailability studies of epigallocatechin-3-gallate loaded solid lipid nanoparticle in rat model

Epigallocatechin-3-gallate (EGCG), derived from green tea, is an active phytochemical against many types of cancer, cardiovascular, neurological and inflammatory diseases. However, its pharmaceutical activity is limited due to low bioavailability and chemical instability. To overcome these limitations, we fabricated spherical, EGCG loaded solid lipid nanoparticles (SLN-EGCG) as an oral delivery system. The SLN-EGCG showed a hydrodynamic diameter of 300.2 ± 3.8 nm with the drug encapsulation efficiency of 81 ± 1.4%. Additionally, a slow and sustained release of EGCG was noted. Mathematical modeling of release kinetic data suggested that the SLN-EGCG followed the Higuchi model and released EGCG via fickian diffusion method. The data on pharmacokinetic parameters indicated significantly improved bioavailability and protection of EGCG from degradation due to encapsulation into SLN. The SLN-EGCG did not show any acute or sub-chronic toxicity when compared with free EGCG in the rat model. Together these data supported the hypothesis that SLN-EGCG is capable of enhancing the bioavailability and stability of EGCG and can be used as an alternative system for oral administration of EGCG.

Polymeric Co-Delivery Systems in Cancer Treatment: An Overview on Component Drugs' Dosage Ratio Effect

Multiple factors are involved in the development of cancers and their effects on survival rate. Many are related to chemo-resistance of tumor cells. Thus, treatment with a single therapeutic agent is often inadequate for successful cancer therapy. Ideally, combination therapy inhibits tumor growth through multiple pathways by enhancing the performance of each individual therapy, often resulting in a synergistic effect. Polymeric nanoparticles prepared from block co-polymers have been a popular platform for co-delivery of combinations of drugs associated with the multiple functional compartments within such nanoparticles. Various polymeric nanoparticles have been applied to achieve enhanced therapeutic efficacy in cancer therapy. However, reported drug ratios used in such systems often vary widely. Thus, the same combination of drugs may result in very different therapeutic outcomes. In this review, we investigated polymeric co-delivery systems used in cancer treatment and the drug combinations used in these systems for synergistic anti-cancer effect. Development of polymeric co-delivery systems for a maximized therapeutic effect requires a deeper understanding of the optimal ratio among therapeutic agents and the natural heterogenicity of tumors.

Nanomedicines as Drug Delivery Carriers of Anti-Tubercular Drugs: From Pathogenesis to Infection Control

In spite of advances in tuberculosis (TB) chemotherapy, TB is still airborne deadly disorder as a major issue of health concern worldwide today. Extensive researches have been focused to develop novel drug delivery systems to shorten the lengthy therapy approaches, prevention of relapses, reducing dose-related toxicities and to rectify technologically related drawbacks of anti-tubercular drugs. Moreover, the rapid emergence of drug resistance, poor patient compliance due to negative therapeutic outcomes and intracellular survival of Mycobacterium highlighted to develop carrier with optimum effectiveness of the anti-tubercular drugs. This could be achieved by targeting and concentrating the drug on the infection reservoir of Mycobacterium. In this article, we briefly compiled the general aspects of Mycobacterium pathogenesis, disease treatment along with progressive updates in novel drug delivery carrier system to enhance therapeutic effects of drug and the high level of patient compliance. Recently developed several vaccines might be shortly available as reported by WHO.

Polymeric curcumin nanoparticles by a facile in situ method for macrophage targeted delivery

Targeting macrophages is a promising strategy for improved therapy of intracellular infections as macrophages exhibit rapid phagocytosis of particles >200 nm. Entrapment of Curcumin (CUR) in nanocarriers could provide bioenhancement and macrophage targeting. We present a simple and facile in situ nanoprecipitation approach for instantaneous and on-site generation of curcumin nanoparticles (ISCurNP). ISCurNP optimised by Box-Behnken design exhibited average size of 208.25 ± 7.55 nm and entrapment efficiency of 90.16 ± 1.17%. Differential scanning calorimetry and X-Ray diffraction confirmed amorphization of CUR in ISCurNP. Sustained release was observed over 72 hr in vitro at lysosomal pH 4.5. Rapid and high uptake in RAW 264.7 macrophages was confirmed by flow cytometry and high performance liquid chromatography. Confocal microscopy established localisation of ISCurNP in lysosomal compartment. The facile in situ nanoprecipitation method provides simple, scalable technology to enable macrophage targeted delivery of CUR, with great promise for improved therapy of intracellular infections.

Therapeutic implications of nano-encapsulated rifabutin, azithromycin & ethambutol against experimental Mycobacterium avium infection in mice

Background & objectives

Mycobacterium avium causes atypical infection in both immunocompetent and immunocompromised individuals. Conventional chemotherapy for M. avium infection is not efficient due to lengthy course of treatment and drug-associated toxic side effects. The present study was aimed at reducing dosing frequency of antimicrobial regimen consisting of azithromycin (AZM), rifabutin (RBT) and ethambutol (EMB) by encapsulation of drugs in nanoparticles (NPs) in experimental M. avium infection in mice.

Methods

Poly (DL-lactide-co-glycolide) NPs containing anti-M. avium drugs were prepared, characterized and studied for their pharmacokinetics and pharmacodynamics parameters. Drug-loaded NPs were further analyzed for their therapeutic efficacy against experimental M. avium infection in mice.

Results

Drug-loaded NPs were of size 227.3±16.4 for RBT, 334.35±11.7 for AZM and 509.85±20.5 for EMB with smooth surface morphology and negative zeta potential. AZM, EMB and RBT from NPs were detectable for 6, 4 and 5 days, respectively, in the mice plasma, whereas free drugs were cleared from mice circulation within 24 h. Chemotherapeutic effects of weekly administered drug-loaded NPs were equivalent to daily administered free drugs.

Interpretation & conclusions

Our findings showed that NPs gave sustained release of drugs inside plasma and organs, thus decreasing dosage frequency, and their weekly dosage had therapeutic efficacy equivalent to daily dosage of free drugs.

Sericin-chitosan doped maleate gellan gum nanocomposites for effective cell damage in Mycobacterium tuberculosis

Polysaccharides are increasingly used as biodegradable nanocarrier to selectively deliver therapeutic agents to specific cells. In this study, maleate gellan gum (MA-GG) formed by addition of free radical polymerizable groups, which can be polymerized presence of acetone to design biodegradable three-dimensional networks, were synthesized by esterification. Natural silk sericin was grafted over the maleate gellan gum surface. Maleate Gellan Gum- Silk Sericin-Chitosan (MA-GG-SS-CS) nanocomposites loaded with rifampicin (RF) and pyrazinamide (PZA) to overcome the problems associated with Tuberculosis (TB) therapy. The pH responsive behavior of gellan gum nanocomposites was reposed by silk sericin and exhibited sustained release of 79% RF and 82% PZA for 120 h at pH 4.0. The designed formulations shows higher antimycobacterial activity and rapid delivery of drugs at TB infected macrophage. Nanomaterial effectively aggregated and internalized into the bacterial cells and MH-S cells. Dual drug release inside the cells makes damage in the cell membrane. Green nanocomposites studies pave the way for important use of macromolecules in pulmonary delivery TB drugs.

EGCG Nanoparticles Attenuate Aluminum Chloride Induced Neurobehavioral Deficits, Beta Amyloid and Tau Pathology in a Rat Model of Alzheimer's Disease

Rational: Alzheimer's disease (AD) is a neurodegenerative pathology characterized by the presence of neuritic plaques and neurofibrillary tangles. Aluminum has been reported to play an important role in the etiology and pathogenesis of this disease. Hence, the present study aimed to evaluate the neuroprotective role of epigallocatechin-gallate (EGCG) loaded nanoparticles (nanoEGCG) against aluminum chloride (AlCl3) induced neurobehavioral and pathological changes in AD induced rats. Method: 100 mg/kg body weight AlCl3 was administered orally for 60 days, which was followed by 10 mg/kg body weight free EGCG and nanoEGCG treatment for 30 days. Morris water maze, open field and novel object recognition tests were employed for neurobehavioral assessment of the rats. This was followed by histopathological assessment of the cortex and the hippocampus in the rat brain. For further validation biochemical, immunohistochemistry and western blot assays were carried out. Result: Aluminum exposure reduced the exploratory and locomotor activities in open field and significantly reduced the memory and learning curve of rats in Morris water maze and novel object recognition tests. These neurobehavioral impairments were significantly attenuated in nanoEGCG treated rats. Histopathological assessment of the cortex and hippocampus of AlCl3 induced rat brains showed the presence of both neuritic plaques and neurofibrillary tangles. In nanoEGCG treated rats this pathology was absent. Significant increase in biochemical, immunohistochemical and protein levels was noted in AlCl3 induced rats. While these levels were greatly reduced in nanoEGCG treated rats. Conclusion: In conclusion, this study strengthens the hypothesis that EGCG nanoparticles can reverse memory loss, neuritic plaque and neurofibrillary tangles formation.

Protein Based Nanostructures for Drug Delivery

The key role of protein based nanostructures has recently revolutionized the nanomedicine era. Protein nanoparticles have turned out to be the major grounds for the transformation of different properties of many conventional materials by virtue of their size and greater surface area which instigates them to be more reactive to some other molecules. Protein nanoparticles have better biocompatibilities and biodegradability and also have the possibilities for surface modifications. These nanostructures can be synthesized by using protein like albumin, gelatin, whey protein, gliadin, legumin, elastin, zein, soy protein, and milk protein. The techniques for their fabrication include emulsification, desolvation, complex coacervation, and electrospray. The characterization parameters of protein nanoparticles comprise particle size, particle morphology, surface charge, drug loading, determination of drug entrapment, and particle structure and in vitro drug release. A plethora of protein nanoparticles applications via different routes of administration are explored and reported by eminent researchers which are highlighted in the present review along with the patents granted for protein nanoparticles as drug delivery carriers.

Nanomaterials in the Prevention, Diagnosis, and Treatment of Mycobacterium Tuberculosis Infections

Despite the tremendous advancements that have been made in biomedical research, Mycobacterium tuberculosis (TB) still remains one of the top 10 causes of death worldwide, outpacing the Human Immunodeficiency Virus as a leading cause of death from an infectious disease. In the light of such significant disease burden, tremendous efforts have been made worldwide to stem this burgeoning spread of disease. The use of nanomaterials in TB management has increased in the past decade, particularly in the areas of early TB detection, prevention, and treatment. Nanomaterials have been proven to be efficacious in the rapid and accurate detection of TB pathogens. Novel nanocarriers have also shown tremendous promise in improving drug delivery, potentially enhancing drug concentrations in target organs while at the same time, reducing treatment frequency. In addition, the engineering of antigen nanocarriers represents an exciting front in TB research, potentially paving the way for the successful development of a new class of effective TB vaccines. This article discusses epidemiology and pathogenesis of TB infections, current TB therapeutics, advanced nanomaterials for anti-TB drug delivery, and TB vaccines. In addition, challenges and future perspectives in developing safe and effective nanomaterials in TB diagnosis and therapy are also presented.

Highlights in nanocarriers for the treatment against cervical cancer

Cervical cancer is the second most common malignant tumor in women worldwide and has a high mortality rate, especially when it is associated with human papillomavirus (HPV). In US, an estimated 12,820 cases of invasive cervical cancer and an estimated 4210 deaths from this cancer will occur in 2017. With rare and very aggressive conventional treatments, one sees in the real need of new alternatives of therapy as the delivery of chemotherapeutic agents by nanocarriers using nanotechnology. This review covers different drug delivery systems applied in the treatment of cervical cancer, such as solid lipid nanoparticles (SNLs), liposomes, nanoemulsions and polymeric nanoparticles (PNPs). The main advantages of drug delivery thus improving pharmacological activity, improving solubility, bioavailability to bioavailability reducing toxicity in the target tissue by targeting of ligands, thus facilitating new innovative therapeutic technologies in a too much needed area. Among the main disadvantage is the still high cost of production of these nanocarriers. Therefore, the aim this paper is review the nanotechnology based drug delivery systems in the treatment of cervical cancer.

How can nanoparticles contribute to antituberculosis therapy?

Therapeutic approaches using nanoparticles are being successfully used in foods and in several fields of medicine, including infectious diseases. Regarding tuberculosis (TB) treatment, nanoparticles can be a useful strategy for two distinct applications: (i) for their intrinsic antimycobacterial activity; (ii) as vehicles for known antitubercular drugs to allow reduction of dose- and drug-associated side-effects and administration via user-friendly administration routes such as pulmonary or oral ones. Promising results were obtained in vitro and in animal Mycobacterium tuberculosis models and need now to be translated into clinical drug candidates. Such a prospect can provide an opportunity regarding the current limited therapeutic options for drug-resistant TB and the scarcity of novel antituberculosis drugs in the drug discovery pipeline.

Targeted delivery of rifampicin to tuberculosis-infected macrophages: design, in-vitro, and in-vivo performance of rifampicin-loaded poly(ester amide)s nanocarriers

We have developed a nano drug delivery system for the treatment of tuberculosis (TB) using rifampicin (RF) encapsulated in poly(ester amide)s nanoparticles (PEA-RF-NPs), which are biocompatible polymers. In this study, biodegradable amino acid based poly(ester amide)s (PEAs) were synthesized by the poly condensation reaction and RF-loaded NPs were fabricated by the dialysis method. The surface morphology and in-vitro drug release efficiency were examined. The effect of time and temperature on the cellular uptake of PEA-RF-NPs in NR8383 cells was evaluated. Fluorescence microscopic results of PEA-RF-NPs from NR8383 cell lines suggest its potential application in treating TB. The antibacterial activity of RF against Mycobacterium smegmatis was also evaluated. Based on these results, this approach provides a new means for controlled and efficient release of RF using the PEA-NPs delivery system and is promising for the treatment of TB.

Inflammation Caused by Nanosized Delivery Systems: Is There a Benefit?

Secondary macrophage cytotoxicity induced by nanoparticles was described before. The study aim was to investigate the role of secondary cytotoxic effect in a macrophage-lung cancer coculture model after nanoparticle treatment in the presence and absence of anti-inflammatory drugs. An in vitro coculture model composed of confluent alveolar macrophage MH-S and A-549 lung cancer cells separated by a 0.4 μm porous membrane was used in the study. Macrophages were treated with two sizes of gelatin nanoparticles and two sizes of poly(isobutyl cyanoacrylate) (PIBCA) nanoparticles, with and without doxorubicin as a chemotherapeutic drug. The treatment effect with and without the presence of anti-inflammatory drug was studied using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The model drugs were ibuprofen, celecoxib, prednisolone, dexamethasone, and methotrexate. Different nanoparticles in different sizes were synthesized with a range of physicochemical characteristics. Doxorubicin loaded nanoparticles were prepared with an entrapment efficiency of 82-83% for PIBCA and 39-42% for gelatin. Nanoparticle treatment of macrophages showed a secondary cytotoxic effect on A-549 cancer cells at 24 and 36 h, with a drop in cell viability of 40-62%. However, this effect was significantly reduced to 10-48% if the macrophages were exposed to anti-inflammatory drugs. When ibuprofen and celecoxib were used the cell viability rebounded between 24 and 36 h. For prednisolone, dexamethasone, and methotrexate the cell viability dropped further between 24 and 36 h. Macrophages exposed to nanoparticles show secondary cytotoxicity, which has a significant antitumor effect in the microclimate of the coculture model. The beneficial nanoparticle treatment effect was significantly reduced if nonsteroidal anti-inflammatory drugs (NSAIDs), glucocorticoids, or methotrexate was given at the same time. The data suggest that anti-inflammatory treatments can decrease the carrier-induced macrophage cytotoxicity and its antitumor effectiveness with chemotherapy.

Fungal diseases: could nanostructured drug delivery systems be a novel paradigm for therapy?

Invasive mycoses are a major problem for immunocompromised individuals and patients in intensive care units. Morbidity and mortality rates of these infections are high because of late diagnosis and delayed treatment. Moreover, the number of available antifungal agents is low, and there are problems with toxicity and resistance. Alternatives for treating invasive fungal infections are necessary. Nanostructured systems could be excellent carriers for antifungal drugs, reducing toxicity and targeting their action. The use of nanostructured systems for antifungal therapy began in the 1990s, with the appearance of lipid formulations of amphotericin B. This review encompasses different antifungal drug delivery systems, such as liposomes, carriers based on solid lipids and nanostructure lipids, polymeric nanoparticles, dendrimers, and others. All these delivery systems have advantages and disadvantages. Main advantages are the improvement in the antifungal properties, such as bioavailability, reduction in toxicity, and target tissue, which facilitates innovative therapeutic techniques. Conversely, a major disadvantage is the high cost of production. In the near future, the use of nanosystems for drug delivery strategies can be used for delivering peptides, including mucoadhesive systems for the treatment of oral and vaginal candidiasis.

Autofluorescent gelatin nanoparticles as imaging probes to monitor matrix metalloproteinase metabolism of cancer cells

In this paper, autofluorescent gelatin nanoparticles were synthesized as matrix metalloproteinase (MMP) responsive probes for cancer cell imaging. A modified two-step desolvation method was employed to generate these nanoparticles whose size was controllable and had stable autofluorescence. As glutaraldehyde was introduced as the crosslinking agent, the generation of Schiff base (CN) and double carbon bond (CC) between glutaraldehyde and gelatin endowed these gelatin nanoparticles distinct autofluorescence. Considering MMPs were usually overexpressed on the surface of cancer cells and they had degradation ability toward gelatin, we utilized these nanoparticles as imaging probes to responsively monitor the MMP metabolism of cancer cells according to the luminance change. As fluorescent probes, these nanoparticles had facile synthesis procedure and good biocompatibility, and provided a smart strategy to monitor cancer cell behaviors. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2854-2860, 2016.

The relevancy of controlled nanocrystallization on rifampicin characteristics and cytotoxicity

Purpose

This article investigated the influence of novel rifampicin nanosuspension (RIF NS) for enhancing drug delivery properties.

Methods

RIF NS was fabricated using the antisolvent precipitation technique. The impact of solvent type and flow rate, stabilizer type and concentration, and stirring time and apparatus together with the solvent–antisolvent volume ratio on its controlled nanocrystallization has been evaluated. NSs were characterized by transmission electron microscopy, particle size and zeta potential analysis, solubility, and dissolution profiles. The compatibility between RIF and the stabilizer was investigated via Fourier transform infrared spectroscopy and the differential scanning calorimetry techniques. The shelf-life stability of the RIF NS was assessed within a period of 3 months at different storage temperatures. Cell cytotoxicity was evaluated using 3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay on lung epithelial cells.

Results

Polyvinyl alcohol at 0.4% w/v, 1:15 methanol to deionized water volume ratio and 30-minutes sonication were the optimal parameters for RIF NS preparation. Nanocrystals were obtained with a nanometeric particle size (101 nm) and a negative zeta potential (−26 mV). NS exhibited a 50-fold enhancement in RIF solubility and 97% of RIF was dissolved after 10 minutes. The RIF NS was stable at 4±0.5°C with no significant change in particle size or zeta potential. The MTT cytotoxicity assay of RIF NS demonstrated a good safety profile and reduction in cell cytotoxicity with half maximal inhibitory concentration values of 0.5 and 0.8 mg/mL for free RIF and RIF NS, respectively.

Conclusion

A novel RIF NS could be followed as an approach for enhancing RIF physicochemical characteristics with a prominence of a safer and better drug delivery.