Therapeutic Nanoparticles and Their Targeted Delivery Applications

Understanding the impact of more realistic low-dose, prolonged engineered nanomaterial exposure on genotoxicity using 3D models of the human liver

BACKGROUND

With the continued integration of engineered nanomaterials (ENMs) into everyday applications, it is important to understand their potential for inducing adverse human health effects. However, standard in vitro hazard characterisation approaches suffer limitations for evaluating ENM and so it is imperative to determine these potential hazards under more physiologically relevant and realistic exposure scenarios in target organ systems, to minimise the necessity for in vivo testing. The aim of this study was to determine if acute (24 h) and prolonged (120 h) exposures to five ENMs (TiO₂, ZnO, Ag, BaSO₄ and CeO₂) would have a significantly different toxicological outcome (cytotoxicity, (pro-)inflammatory and genotoxic response) upon 3D human HepG2 liver spheroids. In addition, this study evaluated whether a more realistic, prolonged fractionated and repeated ENM dosing regime induces a significantly different toxicity outcome in liver spheroids as compared to a single, bolus prolonged exposure.

RESULTS

Whilst it was found that the five ENMs did not impede liver functionality (e.g. albumin and urea production), induce cytotoxicity or an IL-8 (pro-)inflammatory response, all were found to cause significant genotoxicity following acute exposure. Most statistically significant genotoxic responses were not dose-dependent, with the exception of TiO₂. Interestingly, the DNA damage effects observed following acute exposures, were not mirrored in the prolonged exposures, where only 0.2-5.0 µg/mL of ZnO ENMs were found to elicit significant (p ≤ 0.05) genotoxicity. When fractionated, repeated exposure regimes were performed with the test ENMs, no significant (p ≥ 0.05) difference was observed when compared to the single, bolus exposure regime. There was < 5.0% cytotoxicity observed across all exposures, and the mean difference in IL-8 cytokine release and genotoxicity between exposure regimes was 3.425 pg/mL and 0.181%, respectively.

CONCLUSION

In conclusion, whilst there was no difference between a single, bolus or fractionated, repeated ENM prolonged exposure regimes upon the toxicological output of 3D HepG2 liver spheroids, there was a difference between acute and prolonged exposures. This study highlights the importance of evaluating more realistic ENM exposures, thereby providing a future in vitro approach to better support ENM hazard assessment in a routine and easily accessible manner.

Properties and Applications of Nanoparticles from Plant Proteins

Nanoparticles from plant proteins are preferred over carbohydrates and synthetic polymeric-based materials for food, medical and other applications. In addition to their large availability and relatively low cost, plant proteins offer higher possibilities for surface modifications and functionalizing various biomolecules for specific applications. Plant proteins also avoid the immunogenic responses associated with the use of animal proteins. However, the sources of plant proteins are very diverse, and proteins from each source have distinct structures, properties and processing requirements. While proteins from corn (zein) and wheat (gliadin) are soluble in aqueous ethanol, most other plant proteins are insoluble in aqueous conditions. Apart from zein and gliadin nanoparticles (which are relatively easy to prepare), soy proteins, wheat glutenin and proteins from several legumes have been made into nanoparticles. The extraction of soluble proteins, hydrolyzing with alkali and acids, conjugation with other biopolymers, and newer techniques such as microfluidization and electrospraying have been adopted to develop plant protein nanoparticles. Solid, hollow, and core-shell nanoparticles with varying sizes and physical and chemical properties have been developed. Most plant protein nanoparticles have been used as carriers for drugs and as biomolecules for controlled release applications and for stabilizing food emulsions. This review provides an overview of the approaches used to prepare nanoparticles from plant proteins, and their properties and potential applications. The review's specific focus is on the preparation methods and applications, rather than the properties of the proteins, which have been reported in detail in other publications.

Synthesis of Zr-89-Labeled Folic Acid-Conjugated Silica (SiO2) Microwire as a Tumor Diagnostics Carrier for Positron Emission Tomography

This study evaluated the in vivo behavior and accumulation of silica particles in the form of wires, which were actively studied as drug carriers along with spheres, using positron emission tomography (PET). Wire-shaped silicon dioxide (SiO₂) was synthesized at micro-size, using anodic aluminum oxide (AAO), a template, and folic acid (FA), which specifically binds folate receptors (FR) which are overexpressed in many cancers, and which was bound to the wire’s surface to confirm its possible use as a cancer diagnostic agent. In addition, for evaluation using PET, the positron-emitting nuclide ⁸⁹Zr (t_1/2 = 3.3 days) was directly bonded to the hydroxyl group (-OH) on the particle surface. The diameter and shape of the synthesized silica microwires (SMWs) were confirmed using SEM and TEM, the chemical bonding of FA was confirmed through FT–IR and NMR, and the labeling of ⁸⁹Zr was measured by means of radio-thin-layer chromatography (TLC) measurement. Folic acid-conjugated SMWs (FA-SMWs) were found to have a low receptor-mediated uptake in cell internalization evaluation, but in PET studies, FA-SMWs stayed longer at the tumor site. In conclusion, we successfully synthesized a homogeneous silica microwire for drug delivery, we confirmed that the FA-conjugated sample remains at the tumor site for a relatively longer time, and we have reported the characteristic in vivo behavior of ⁸⁹Zr-FA-SMWs.

Osteoporosis and Its Nanotechnology-Based Advanced Treatment-An Overview

Human Immunodeficiency Virus (HIV) is a global pandemic that has contributed to the burden of disease, and the synergistic interaction between Herpes Simplex Virus (HSV) and HIV has assisted further in the spread of the HIV disease. Moreover, several chemotherapeutic treatment options from antiviral monotherapy to highly active antiretroviral therapy (HAART) have been adopted to manage the infection; however, HIV has developed new mechanisms against these active pharmaceutical agents (APAs), limiting the effect of the drugs. In this article, we reviewed different nanoparticles and their antiviral potency against HSV and HIV infection as well as the effect of drug encapsulated nanoparticles using different drug delivery systems as they palliate to some flaws or deficiencies that the stand-alone drugs present. Drug encapsulated nanoparticles show better treatment outcomes of HSV and HIV infection. The nanoparticles can transverse the anatomic privilege sites to exert their therapeutic effect, and a prolonged and higher dose of the encapsulated therapeutic agent can ease the dosage frequency, thus palliating low drug compliance which the stand-alone drugs fail to perform. Therefore, it is clear that nanoparticles prevent antiviral drug resistance by maintaining sustained drug release over an extended period, improving the therapeutic effect of the entrapped drug.

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.

Nanoparticles as therapeutic options for treating multidrug-resistant bacteria: research progress, challenges, and prospects

Resistance to antimicrobial agents has been alarming in recent years and poses a huge public health threat globally according to the WHO. The increase in morbidity and mortality resulting from microbial infections has been attributed to the emergence of multidrug-resistant microbes. Associated with the increase in multidrug resistance is the lack of new and effective antimicrobials. This has led to global initiatives to identify novel and more effective antimicrobial agents in addition to discovering novel and effective drug delivery and targeting methods. The use of nanoparticles as novel biomaterials to fully achieve this feat is currently gaining global attention. Nanoparticles could become an indispensable viable therapeutic option for treating drug-resistant infections. Of all the nanoparticles, the metals and metal oxide nanoparticles appear to offer the most promise and have attracted tremendous interest from many researchers. Moreover, the use of nanomaterials in photothermal therapy has received considerable attention over the years. This review provides current insight on antimicrobial resistance as well as the mechanisms of nanoparticle antibacterial activity. It offers an in-depth review of all the recent findings in the use of nanomaterials as agents against multi-resistant pathogenic bacteria. Also, nanomaterials that can respond to light stimuli (photothermal therapy) to kill microbes and facilitate enhanced drug delivery and release are discussed. Moreover, the synergistic interactions of nanoparticles with antibiotics and other nanomaterials, microbial adaptation strategies to nanoparticles, current challenges, and future prospects were extensively discussed.

Nanoparticles as therapeutic options for treating multidrug-resistant bacteria: research progress, challenges, and prospects

Resistance to antimicrobial agents has been alarming in recent years and poses a huge public health threat globally according to the WHO. The increase in morbidity and mortality resulting from microbial infections has been attributed to the emergence of multidrug-resistant microbes. Associated with the increase in multidrug resistance is the lack of new and effective antimicrobials. This has led to global initiatives to identify novel and more effective antimicrobial agents in addition to discovering novel and effective drug delivery and targeting methods. The use of nanoparticles as novel biomaterials to fully achieve this feat is currently gaining global attention. Nanoparticles could become an indispensable viable therapeutic option for treating drug-resistant infections. Of all the nanoparticles, the metals and metal oxide nanoparticles appear to offer the most promise and have attracted tremendous interest from many researchers. Moreover, the use of nanomaterials in photothermal therapy has received considerable attention over the years. This review provides current insight on antimicrobial resistance as well as the mechanisms of nanoparticle antibacterial activity. It offers an in-depth review of all the recent findings in the use of nanomaterials as agents against multi-resistant pathogenic bacteria. Also, nanomaterials that can respond to light stimuli (photothermal therapy) to kill microbes and facilitate enhanced drug delivery and release are discussed. Moreover, the synergistic interactions of nanoparticles with antibiotics and other nanomaterials, microbial adaptation strategies to nanoparticles, current challenges, and future prospects were extensively discussed.

Polymeric Nanocarriers with Luminescent Colloidal Nanoplatelets as Hydrophilic and Non-Toxic Two-Photon Bioimaging Agents

Introduction

Semiconductor nanoplatelets (NPLs) are promising materials for nonlinear optical microscopy since they feature good two-photon absorption (TPA) properties, narrow photoluminescence spectra and high quantum yields of luminescence. Nevertheless, the use of semiconductor NPLs is inevitably connected with concerns about heavy metal ion toxicity and their intrinsically hydrophobic character.

Methods

Our contribution focuses on the design and engineering of coloidal bionanomaterial consisting of two-dimensional highly luminescent CdSe semiconductor NPLs loaded into spherical and homogeneous polymeric nanocarriers (NCs) based on poly(ethylene oxide) and poly(propylene oxide) block co-polymer. The biocompatibility and usefulness of the NPLs-loaded polymeric NCs in two-photon induced bioimaging was demonstrated invitroby cytotoxicity and two-photon microscopic studies using eukaryotic (normal fibroblasts and cancer ovarian) cells.

Results

The encapsulated NPLs maintain their intensive and spectrally narrow photoluminescence, as well as preserve good TPA properties, while the surrounding polymer shell imparts hydrophilic character and non-toxicity towards eukaryotic cells. Specifically, TPA cross-sections of the colloidal NCs loaded with NPLs show large values reaching up to 2.0 × 10⁸ GM, with simultaneously two-photon brightness reaching 2.2 × 10⁷ GM at 870 nm. MTT proliferation assay performed on cell lines treated with encapsulated NPLs revealed at least 70% viability of normal human gingival fibroblast (HGF) and cancer ovarian (MDAH-2774) cells, while the results of multiphoton imaging of murine (L-929) fibroblasts suggest that the encapsulated NPLs are capable of labelling the target cells enabling their visualization.

Conclusion

As a result, we obtained water dispersible and temporally stable hydrophilic NPLs-loaded NCs that offer excellent, both one- and two-photon excited fluorescence preserving optical properties of the raw hydrophobic and colloidal NPLs. The biological responses upon eukaryotic cells indicate that the encapsulation process protects cells from the toxic influence of cadmium simultaneously preserving the unique multiphoton properties of the active cargo which opens a promising perspective for its application in multiphoton cancer bioimaging excited at the “optical transmission window” of biological tissues in near-infrared range.

Challenge of diabetes mellitus and researchers’ contributions to its control

The aim of this review study was to assess the past significant events on diabetes mellitus, transformations that took place over the years in the medical records of treatment, countries involved, and the researchers who brought about the revolutions. This study used the content analysis to report the existence of diabetes mellitus and the treatments provided by researchers to control it. The focus was mainly on three main types of diabetes (type 1, type 2, and type 3 diabetes). Ethical consideration has also helped to boost diabetic studies globally. The research has a history path from pharmaceuticals of organic-based drugs to metal-based drugs with their nanoparticles in addition to the impacts of nanomedicine, biosensors, and telemedicine. Ongoing and future studies in alternative medicine such as vanadium nanoparticles (metal nanoparticles) are promising.

Chitosan-Based Nanoparticles of Targeted Drug Delivery System in Breast Cancer Treatment

Breast cancer remains one of the world's most dangerous diseases because of the difficulty of finding cost-effective and specific targets for effective and efficient treatment methods. The biodegradability and biocompatibility properties of chitosan-based nanoparticles (ChNPs) have good prospects for targeted drug delivery systems. ChNPs can transfer various antitumor drugs to targeted sites via passive and active targeting pathways. The modification of ChNPs has attracted the researcher to the loading of drugs to targeted cancer cells. The objective of our review was to summarize and discuss the modification in ChNPs in delivering anticancer drugs against breast cancer cells from published papers recorded in Scopus, PubMed, and Google Scholar. In order to improve cellular uptake, drug accumulation, cytotoxicity, and selectivity, we examined different kinds of modification of ChNPs. Notably, these forms of ChNPs use the characteristics of the enhanced permeability and retention (EPR) effect as a proper parameter and different biological ligands, such as proteins, peptides, monoclonal antibodies, and small particles. In addition, as a targeted delivery system, ChNPs provided and significantly improved the delivery of drugs into specific breast cancer cells (MDA-MB-231, 4T1 cells, SK-BR-3, MCF-7, T47D). In conclusion, a promising technique is presented for increasing the efficacy, selectivity, and effectiveness of candidate drug carriers in the treatment of breast cancer.

Non-Viral Vector-Mediated Gene Therapy for ALS: Challenges and Future Perspectives

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disease, for which no effective treatment is yet available to either slow or terminate it. Recent advances in gene therapy renew hope for developing an effective approach to control this disease. Non-viral vectors, such as lipid- and polymer-based nanoparticles, cationic polymers, and exosomes, can effectively transfer genes into primary neurons. The resulting gene expression can be long-term, stable, and without immunological complications, which is essential for the effective management of neurological disorders. This Review will first describe the current research and clinical stage of novel therapies for ALS. It will then touch on the journey of non-viral vector use in ALS, subsequently highlighting the application of non-viral vector-mediated gene therapy. The bottlenecks in the translation of non-viral vectors for ALS treatment are also discussed, including the biological barriers of systemic administration and the issues of "when, where, and how much?" for effective gene delivery. The prospect of employing emerging techniques, such as CRISPR-Cas9 gene editing, stem cell methodology, and low-intensity focused ultrasound for fueling the transport of non-viral vectors to the central nervous system for personalized gene therapy, is briefly discussed in the context of ALS. Despite the challenging road that lies ahead, with the current expansion in interest and technological advancement in non-viral vector-delivered gene therapy for ALS, we hold hope that the field is headed toward a positive future.

All-trans retinoic acid in anticancer therapy: how nanotechnology can enhance its efficacy and resolve its drawbacks

Introduction: All-trans retinoic acid (ATRA, tretinoin) is the main drug used in the treatment of acute promyelocytic leukemia (APL). Despite its impressive activity against APL, the same could not be clinically observed in other types of cancer. Nanotechnology can be a tool to enhance ATRA anticancer efficacy and resolve its drawbacks in APL as well as in other malignancies.Areas covered: This review covers ATRA use in APL and non-APL cancers, the problems that were found in ATRA therapy and how nanoencapsulation can aid to circumvent them. Pre-clinical results obtained with nanoencapsulated ATRA are shown as well as the two ATRA products based on nanotechnology that were clinically tested: ATRA-IV® and Apealea®.Expert opinion: ATRA presents interesting properties to be used in anticancer therapy with a notorious differentiation and antimetastatic activity. Bioavailability and resistance limitations impair the use of ATRA in non-APL cancers. Nanotechnology can circumvent these issues and provide tools to enhance its anticancer activities, such as co-loading of multiple drug and active targeting to tumor site.

Recent advances in prodrug-based nanoparticle therapeutics

Extensive research into prodrug modification of active pharmaceutical ingredients and nanoparticle drug delivery systems has led to unprecedented levels of control over the pharmacological properties of drugs and resulted in the approval of many prodrug or nanoparticle-based therapies. In recent years, the combination of these two strategies into prodrug-based nanoparticle drug delivery systems (PNDDS) has been explored as a way to further advance nanomedicine and identify novel therapies for difficult-to-treat indications. Many of the PNDDS currently in the clinical development pipeline are expected to enter the market in the coming years, making the rapidly evolving field of PNDDS highly relevant to pharmaceutical scientists. This review paper is intended to introduce PNDDS to the novice reader while also updating those working in the field with a comprehensive summary of recent efforts. To that end, first, an overview of FDA-approved prodrugs is provided to familiarize the reader with their advantages over traditional small molecule drugs and to describe the chemistries that can be used to create them. Because this article is part of a themed issue on nanoparticles, only a brief introduction to nanoparticle-based drug delivery systems is provided summarizing their successful application and unfulfilled opportunities. Finally, the review's centerpiece is a detailed discussion of rationally designed PNDDS formulations in development that successfully leverage the strengths of prodrug and nanoparticle approaches to yield highly effective therapeutic options for the treatment of many diseases.

Polymeric and Lipid Nanoparticles: Which Applications in Pediatrics?

This review aims to provide the state of the art on polymeric and lipid nanoparticles, used or suggested to approach pediatric diseases’ problems and needs, and to inspire new researches in this field. Several drugs are currently not available in formulations suitable for pediatric patients. The United States Pediatric Formulation Initiative suggested applying new technologies to pediatric drug formulations, for instance, nanotechnology. The literature analysis showed that polymeric and lipid nanoparticles have been widely studied to treat pediatric diseases, and albumin nanoparticles and liposomes are already used in clinical practice. Nevertheless, these studies are focused almost exclusively on pediatric cancer treatment. Although nanomedicine may solve many needs of pediatric diseases and medicines, the unavailability of data on pharmacokinetics, safety and efficacy of both drugs and nanoparticles in pediatric patients limits the development of new pediatric medicines based on nanoparticles. Therefore, nanomedicine applied in pediatrics remains a significant challenge in the near future.

Antibacterial composite coatings of MgB2 powders embedded in PVP matrix

Three commercial powders of MgB₂ were tested in vitro by MTS and LDH cytotoxicity tests on the HS27 dermal cell line. Depending on powders, the toxicity concentrations were established in the range of 8.3–33.2 µg/ml. The powder with the lowest toxicity limit was embedded into polyvinylpyrrolidone (PVP), a biocompatible and biodegradable polymer, for two different concentrations. The self-replenishing MgB₂-PVP composite materials were coated on substrate materials (plastic foil of the reservoir and silicon tubes) composing a commercial urinary catheter. The influence of the PVP-reference and MgB₂-PVP novel coatings on the bacterial growth of Staphylococcus aureus ATCC 25923, Enterococcus faecium DMS 13590, Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, in planktonic and biofilm state was assessed in vitro at 6, 24, and 48 h of incubation time. The MgB₂-PVP coatings are efficient both against planktonic microbes and microbial biofilms. Results open promising applications for the use of MgB₂ in the design of anti-infective strategies for different biomedical devices and systems.

Nanobiosystems for Antimicrobial Drug-Resistant Infections

The worldwide increased bacterial resistance toward antimicrobial therapeutics has led investigators to search for new therapeutic options. Some of the options currently exploited to treat drug-resistant infections include drug-associated nanosystems. Additionally, the use of bacteriophages alone or in combination with drugs has been recently revisited; some studies utilizing nanosystems for bacteriophage delivery have been already reported. In this review article, we focus on nine pathogens that are the leading antimicrobial drug-resistant organisms, causing difficult-to-treat infections. For each organism, the bacteriophages and nanosystems developed or used in the last 20 years as potential treatments of pathogen-related infections are discussed. Summarizing conclusions and future perspectives related with the potential of such nano-antimicrobials for the treatment of persistent infections are finally highlighted.

Nanotechnology based solutions for anti-leishmanial impediments: a detailed insight

As a neglected tropical disease, Leishmaniasis is significantly instigating morbidity and mortality across the globe. Its clinical spectrum varies from ulcerative cutaneous lesions to systemic immersion causing hyperthermic hepato-splenomegaly. Curbing leishmanial parasite is toughly attributable to the myriad obstacles in existing chemotherapy and immunization. Since the 1990s, extensive research has been conducted for ameliorating disease prognosis, by resolving certain obstacles of conventional therapeutics viz. poor efficacy, systemic toxicity, inadequate drug accumulation inside the macrophage, scarce antigenic presentation to body's immune cells, protracted length and cost of the treatment. Mentioned hurdles can be restricted by designing nano-drug delivery system (nano-DDS) of extant anti-leishmanials, phyto-nano-DDS, surface modified-mannosylated and thiolated nano-DDS. Likewise, antigen delivery with co-transportation of suitable adjuvants would be achievable through nano-vaccines. In the past decade, researchers have engineered nano-DDS to improve the safety profile of existing drugs by restricting their release parameters. Polymerically-derived nano-DDS were found as a suitable option for oral delivery as well as SLNs due to pharmacokinetic re-modeling of drugs. Mannosylated nano-DDS have upgraded macrophage internalizing of nanosystem and the entrapped drug, provided with minimal toxicity. Cutaneous Leishmaniasis (CL) was tackling by the utilization of nano-DDS designed for topical delivery including niosomes, liposomes, and transfersomes. Transfersomes, however, appears to be superior for this purpose. The nanotechnology-based solution to prevent parasitic resistance is the use of Thiolated drug-loaded and multiple drugs loaded nano-DDS. These surfaces amended nano-DDS possess augmented IC50 values in comparison to conventional drugs and un-modified nano-DDS. Phyto-nano-DDS, another obscure horizon, have also been evaluated for their anti-leishmanial response, however, more intense assessment is a prerequisite. Impoverished Cytotoxic T-cells response followed by Leishmanial antigen proteins delivery have also been vanquished using nano-adjuvants. The eminence of nano-DDS for curtailment of anti-leishmanial chemotherapy and immunization associated challenges are extensively summed up in this review. This expedited approach is ameliorating the Leishmaniasis management successfully. Alongside, total to partial eradication of this disease can be sought along with associated co-morbidities.

Cancer Nanopharmaceuticals: Physicochemical Characterization and In Vitro/In Vivo Applications

Physicochemical, pharmacokinetic, and biopharmaceutical characterization tools play a key role in the assessment of nanopharmaceuticals' potential imaging analysis and for site-specific delivery of anti-cancers to neoplastic cells/tissues. If diagnostic tools and therapeutic approaches are combined in one single nanoparticle, a new platform called nanotheragnostics is generated. Several analytical technologies allow us to characterize nanopharmaceuticals and nanoparticles and their properties so that they can be properly used in cancer therapy. This paper describes the role of multifunctional nanoparticles in cancer diagnosis and treatment, describing how nanotheragnostics can be useful in modern chemotherapy, and finally, the challenges associated with the commercialization of nanoparticles for cancer therapy.

Lichens-A Potential Source for Nanoparticles Fabrication: A Review on Nanoparticles Biosynthesis and Their Prospective Applications

Green synthesis of nanoparticles (NPs) is a safe, eco-friendly, and relatively inexpensive alternative to conventional routes of NPs production. These methods require natural resources such as cyanobacteria, algae, plants, fungi, lichens, and naturally extracted biomolecules such as pigments, vitamins, polysaccharides, proteins, and enzymes to reduce bulk materials (the target metal salts) into a nanoscale product. Synthesis of nanomaterials (NMs) using lichen extracts is a promising eco-friendly, simple, low-cost biological synthesis process. Lichens are groups of organisms including multiple types of fungi and algae that live in symbiosis. Until now, the fabrication of NPs using lichens has remained largely unexplored, although the role of lichens as natural factories for synthesizing NPs has been reported. Lichens have a potential reducible activity to fabricate different types of NMs, including metal and metal oxide NPs and bimetallic alloys and nanocomposites. These NPs exhibit promising catalytic and antidiabetic, antioxidant, and antimicrobial activities. To the best of our knowledge, this review provides, for the first time, an overview of the main published studies concerning the use of lichen for nanofabrication and the applications of these NMs in different sectors. Moreover, the possible mechanisms of biosynthesis are discussed, together with the various optimization factors influencing the biological synthesis and toxicity of NPs.

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.

Differences in surface chemistry of iron oxide nanoparticles result in different routes of internalization

The efficient entry of nanotechnology-based pharmaceuticals into target cells is highly desired to reach high therapeutic efficiency while minimizing the side effects. Despite intensive research, the impact of the surface coating on the mechanism of nanoparticle uptake is not sufficiently understood yet. Herein, we present a mechanistic study of cellular internalization pathways of two magnetic iron oxide nanoparticles (MNPs) differing in surface chemistry into A549 cells. The MNP uptake was investigated in the presence of different inhibitors of endocytosis and monitored by spectroscopic and imaging techniques. The results revealed that the route of MNP entry into cells strongly depends on the surface chemistry of the MNPs. While serum bovine albumin-coated MNPs entered the cells via clathrin-mediated endocytosis (CME), caveolin-mediated endocytosis (CavME) or lipid rafts were preferentially involved in the internalization of polyethylene glycol-coated MNPs. Our data indicate that surface engineering can contribute to an enhanced delivery efficiency of nanoparticles.

Bactericidal Properties of Rod-, Peanut-, and Star-Shaped Gold Nanoparticles Coated with Ceragenin CSA-131 against Multidrug-Resistant Bacterial Strains

Background: The ever-growing number of infections caused by multidrug-resistant (MDR) bacterial strains requires an increased effort to develop new antibiotics. Herein, we demonstrate that a new class of gold nanoparticles (Au NPs), defined by shape and conjugated with ceragenin CSA-131 (cationic steroid antimicrobial), display strong bactericidal activity against intractable superbugs. Methods: For the purpose of research, we developed nanosystems with rod- (AuR NPs@CSA-131), peanut-(AuP NPs@CSA-131) and star-shaped (AuS NPs@CSA-131) metal cores. Those nanosystems were evaluated against bacterial strains representing various groups of MDR (multidrug-resistant) Gram-positive (MRSA, MRSE, and MLS_b) and Gram-negative (ESBL, AmpC, and CR) pathogens. Assessment of MICs (minimum inhibitory concentrations)/MBCs (minimum bactericidal concentrations) and killing assays were performed as a measure of their antibacterial activity. In addition to a comprehensive analysis of bacterial responses involving the generation of ROS (reactive oxygen species), plasma membrane permeabilization and depolarization, as well as the release of protein content, were performed to investigate the molecular mechanisms of action of the nanosystems. Finally, their hemocompatibility was assessed by a hemolysis assay. Results: All of the tested nanosystems exerted potent bactericidal activity in a manner resulting in the generation of ROS, followed by damage of the bacterial membranes and the leakage of intracellular content. Notably, the killing action occurred with all of the bacterial strains evaluated, including those known to be drug resistant, and at concentrations that did not impact the growth of host cells. Conclusions: Conjugation of CSA-131 with Au NPs by covalent bond between the COOH group from MHDA and NH₃ from CSA-131 potentiates the antimicrobial activity of this ceragenin if compared to its action alone. Results validate the development of AuR NPs@CSA-131, AuP NPs@CSA-131, and AuS NPs@CSA-131 as potential novel nanoantibiotics that might effectively eradicate MDR bacteria.

Nanoformulations for Delivery of Pentacyclic Triterpenoids in Anticancer Therapies

The search for safe and effective anticancer therapies is one of the major challenges of the 21st century. The ineffective treatment of cancers, classified as civilization diseases, contributes to a decreased quality of life, health loss, and premature mortality in oncological patients. Many natural phytochemicals have anticancer potential. Pentacyclic triterpenoids, characterized by six- and five-membered ring structures, are one of the largest class of natural metabolites sourced from the plant kingdom. Among the known natural triterpenoids, we can distinguish lupane-, oleanane-, and ursane-types. Pentacyclic triterpenoids are known to have many biological activities, e.g., anti-inflammatory, antibacterial, hepatoprotective, immunomodulatory, antioxidant, and anticancer properties. Unfortunately, they are also characterized by poor water solubility and, hence, low bioavailability. These pharmacological properties may be improved by both introducing some modifications to their native structures and developing novel delivery systems based on the latest nanotechnological achievements. The development of nanocarrier-delivery systems is aimed at increasing the transport capacity of bioactive compounds by enhancing their solubility, bioavailability, stability in vivo and ensuring tumor-targeting while their toxicity and risk of side effects are significantly reduced. Nanocarriers may vary in sizes, constituents, shapes, and surface properties, all of which affect the ultimate efficacy and safety of a given anticancer therapy, as presented in this review. The presented results demonstrate the high antitumor potential of systems for delivery of pentacyclic triterpenoids.

Potential therapeutic agents to COVID-19: An update review on antiviral therapy, immunotherapy, and cell therapy

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in Wuhan, China, in December 2020 and coronavirus disease 19 (COVID-19) was later announced as pandemic by the World Health Organization (WHO). Since then, several studies have been conducted on the prevention and treatment of COVID-19 by potential vaccines and drugs. Although, the governments and global population have been attracted by some vaccine production projects, the presence of SARS-CoV-2-specific antiviral drugs would be an urge necessity in parallel with the efficient preventive vaccines. Various nonspecific drugs produced previously against other bacterial, viral, and parasite infections were recently evaluated for treating patients with COVID-19. In addition to therapeutic properties of these anti-COVID-19 compounds, some adverse effects were observed in different human organs as well. Not only several attentions were paid to antiviral therapy and treatment of COVID-19, but also nanomedicine, immunotherapy, and cell therapy were conducted against this viral infection. In this review study, we planned to introduce the present and potential future treatment strategies against COVID-19 and define the advantages and disadvantages of each treatment strategy.

Targeting Chronic Myeloid Leukemia Stem/Progenitor Cells Using Venetoclax-Loaded Immunoliposome

CML is a hematopoietic stem-cell disorder emanating from breakpoint cluster region/Abelson murine leukemia 1 (BCR/ABL) translocation. Introduction of different TKIs revolutionized treatment outcome in CML patients, but CML LSCs seem insensitive to TKIs and are detectable in newly diagnosed and resistant CML patients and in patients who discontinued therapy. It has been reported that CML LSCs aberrantly express some CD markers such as CD26 that can be used for the diagnosis and for targeting. In this study, we confirmed the presence of CD26+ CML LSCs in newly diagnosed and resistant CML patients. To selectively target CML LSCs/progenitor cells that express CD26 and to spare normal HSCs/progenitor cells, we designed a venetoclax-loaded immunoliposome (IL-VX). Our results showed that by using this system we could selectively target CD26+ cells while sparing CD26- cells. The efficiency of venetoclax in targeting CML LSCs has been reported and our system demonstrated a higher potency in cell death induction in comparison to free venetoclax. Meanwhile, treatment of patient samples with IL-VX significantly reduced CD26+ cells in both stem cells and progenitor cells population. In conclusion, this approach showed that selective elimination of CD26+ CML LSCs/progenitor cells can be obtained in vitro, which might allow in vivo reduction of side effects and attainment of treatment-free, long-lasting remission in CML patients.

Nanomaterials as Novel Cardiovascular Theranostics

Cardiovascular diseases (CVDs) are a group of conditions associated with heart and blood vessels and are considered the leading cause of death globally. Coronary heart disease, atherosclerosis, myocardial infarction represents the CVDs. Since CVDs are associated with a series of pathophysiological conditions with an alarming mortality and morbidity rate, early diagnosis and appropriate therapeutic approaches are critical for saving patients’ lives. Conventionally, diagnostic tools are employed to detect disease conditions, whereas therapeutic drug candidates are administered to mitigate diseases. However, the advent of nanotechnological platforms has revolutionized the current understanding of pathophysiology and therapeutic measures. The concept of combinatorial therapy using both diagnosis and therapeutics through a single platform is known as theranostics. Nano-based theranostics are widely used in cancer detection and treatment, as evident from pre-clinical and clinical studies. Nanotheranostics have gained considerable attention for the efficient management of CVDs. The differential physicochemical properties of engineered nanoparticles have been exploited for early diagnosis and therapy of atherosclerosis, myocardial infarction and aneurysms. Herein, we provided the information on the evolution of nano-based theranostics to detect and treat CVDs such as atherosclerosis, myocardial infarction, and angiogenesis. The review also aims to provide novel avenues on how nanotherapeutics’ trending concept could transform our conventional diagnostic and therapeutic tools in the near future.

Therapeutic nanostructures and nanotoxicity

Nanotechnology, with its continuous advancement, leads to the development of nanoscale-level therapeutics to mitigate many complex diseases. This results in the emergence of numerous novel nanomaterials and its composite products into the market such as liposome, polymeric nanoparticles, dendrimers, and nanostructured lipid carrier. However, their application is always determined by a high benefit to risk ratio. Very few research have been done on the toxicity assessment of nanoparticles in the biological system; therefore, the limited knowledge regarding the toxicity profile of nanotherapeutics is available leading to the ignorance of its side effects. Nanoparticles can distribute in the whole body through translocating in the bloodstream by crossing membrane barriers efficiently and shows effect in organs and tissues at cellular and molecular levels. The interaction of nanoparticle with cell may consequences into nanotoxicity. The narrow size distribution, large surface area to mass ratio and surface properties of nanoparticle are significantly associated with nanotoxicity. Nanoparticles can enter into the tissue and cell by invading the membranes and cause cellular injury as well as toxicity. Therefore, the exploration of mechanisms of nanotoxicity has prime importance now a day. The toxicity assessment should be an integral part of the development of nanotherapeutics using various toxicity evaluation models. This review has focused on the exploration of different nanostructures for therapeutic delivery system along with its physicochemical characteristics responsible for adverse effects on human biology, various toxicity evaluation models, and environmental and regulatory hurdles.

Polymeric Nanoparticles for Antimicrobial Therapies: An Up-To-Date Overview

Despite the many advancements in the pharmaceutical and medical fields and the development of numerous antimicrobial drugs aimed to suppress and destroy pathogenic microorganisms, infectious diseases still represent a major health threat affecting millions of lives daily. In addition to the limitations of antimicrobial drugs associated with low transportation rate, water solubility, oral bioavailability and stability, inefficient drug targeting, considerable toxicity, and limited patient compliance, the major cause for their inefficiency is the antimicrobial resistance of microorganisms. In this context, the risk of a pre-antibiotic era is a real possibility. For this reason, the research focus has shifted toward the discovery and development of novel and alternative antimicrobial agents that could overcome the challenges associated with conventional drugs. Nanotechnology is a possible alternative, as there is significant evidence of the broad-spectrum antimicrobial activity of nanomaterials and nanoparticles in particular. Moreover, owing to their considerable advantages regarding their efficient cargo dissolving, entrapment, encapsulation, or surface attachment, the possibility of forming antimicrobial groups for specific targeting and destruction, biocompatibility and biodegradability, low toxicity, and synergistic therapy, polymeric nanoparticles have received considerable attention as potential antimicrobial drug delivery agents. In this context, the aim of this paper is to provide an up-to-date overview of the most recent studies investigating polymeric nanoparticles designed for antimicrobial therapies, describing both their targeting strategies and their effects.

Near-Infrared Light-Triggered Thermosensitive Liposomes Modified with Membrane Peptides for the Local Chemo/Photothermal Therapy of Melanoma

Purpose

A near-infrared (NIR)-triggered trans-activating transcriptional activator (TAT)-based targeted drug delivery system for the combined chemo/photothermal therapy of melanoma, namely, TAT-TSL-TMZ (temozolomide)/IR820, was developed for the first time.

Methods

TAT-TSL-TMZ/IR820 liposomes were synthesized via thin-film dispersion and sonication. IR820 and TMZ were encased in the inner layer and lipid bilayer of the liposomes, respectively.

Results

Dynamic light scattering results showed that the liposomes had an average hydrodynamic size of 166.9 nm and a zeta potential of -2.55 mV. The encapsulation rates of TMZ and IR820 were 35.4% and 28.6%, respectively. The heating curve obtained under near-infrared (NIR) laser irradiation showed that TAT-TSL-TMZ/IR820 liposomes had good photothermal conversion efficiency. The in vitro drug release curve revealed that NIR laser irradiation could accelerate drug release from TAT-TSL-TMZ/IR820 liposomes. The results of inverted fluorescence microscopy and flow cytometry proved that the uptake of TAT-TSL-TMZ/IR820 liposomes by human melanoma cells (MV3 cells) was concentration-dependent and that the liposomes modified with membrane peptides were more likely to be ingested by cells than unmodified liposomes. Confocal laser scanning microscopy indicated that TAT-TSL-TMZ/IR820 liposomes entered MV3 cells via endocytosis and was stored in lysosomes. In addition, TAT-TSL-TMZ/IR820 liposomes exposed to NIR laser showed 89.73% reduction in cell viability.

Conclusion

This study investigated the photothermal conversion, cell uptake, colocation and chemo/photothermal effect of TAT-TSL-TMZ/IR820 liposomes.

Evaluation of the Antiviral Activity of Sitagliptin-Glatiramer Acetate Nano-Conjugates against SARS-CoV-2 Virus

The outbreak of the COVID-19 pandemic in China has become an urgent health and economic challenge. There is a current race for developing strategies to treat and/or prevent COVID-19 worldwide. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the strain of coronavirus that causes COVID-19. The aim of the present work was to evaluate the efficacy of the combined complex (nano-conjugates) of two FDA-approved drugs, sitagliptin (SIT) and glatiramer acetate (GA), against a human isolate of the SARS-CoV-2 virus. SIT-GA nano-conjugates were prepared according to a full three-factor bilevel (2³) factorial design. The SIT concentration (mM, X₁), GA concentration (mM, X₂), and pH (X₃) were selected as the factors. The particle size (nm, Y₁) and zeta potential (mV, Y₂) were assessed as responses. Characterization of the optimized formula for the Fourier-transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) was carried out. In addition, the half-maximal inhibitory concentration (IC₅₀) in Vero-E6 epithelial cells previously infected with the virus was investigated. The results revealed that the optimized formula of the prepared complex was a 1:1 SIT:GA molar ratio at a pH of 10, which met the required criteria with a desirability value of 0.878 and had a particle size and zeta potential at values of 77.42 nm and 27.67 V, respectively. The SIT-GA nano-complex showed antiviral potential against an isolate of SARS-CoV-2 with IC50 values of 16.14, 14.09, and 8.52 µM for SIT, GA, and SIT-GA nano-conjugates, respectively. Molecular docking has shown that the formula’s components have a high binding affinity to the COVID 3CL protease, essential for coronavirus replication, paralleled by 3CL protease inhibition (IC₅₀ = 2.87 µM). An optimized formulation of SIT-GA could guarantee both enhanced deliveries to target cells and improved cellular uptake. Further clinical studies are being carried out to validate the clinical efficacy of the optimized formulation against SARS-CoV-2.

Microbial Interkingdom Biofilms and the Quest for Novel Therapeutic Strategies

Fungal and bacterial species interact with each other within polymicrobial biofilm communities in various niches of the human body. Interactions between these species can greatly affect human health and disease. Diseases caused by polymicrobial biofilms pose a major challenge in clinical settings because of their enhanced virulence and increased drug tolerance. Therefore, different approaches are being explored to treat fungal-bacterial biofilm infections. This review focuses on the main mechanisms involved in polymicrobial drug tolerance and the implications of the polymicrobial nature for the therapeutic treatment by highlighting clinically relevant fungal-bacterial interactions. Furthermore, innovative treatment strategies which specifically target polymicrobial biofilms are discussed.

Recent advances in breast cancer immunotherapy: The promising impact of nanomedicines

Breast cancer (BC) is one of the prevalent cancers among women. Generally, the treatment of BC is mostly based on several prominent strategies, including chemotherapy, surgery, endocrine therapy, molecular targeted therapy, and radiation. Owing to the growing knowledge about the complexity of BC pathobiology, immunotherapy as a promising treatment modality has substantially improved the patients' care in the clinic. Immunotherapy is used to harness the patient's immune system to recognize and battle devious cancer cells. As a novel therapy approach, this emerging strategy targets the key molecular entities of tumor tissue. To achieve maximal therapeutic impacts, the dynamic interplay between cancer and immune cells needs to be fully comprehended. The key molecular machinery of solid tumors can be targeted by nanoscale immunomedicines. While discussing the potential biomarkers involved in the initiation and progression of BC, we aimed to provide comprehensive insights into the immunotherapy and articulate the recent advances in terms of the therapeutic strategies used to control this disease, including immune checkpoint inhibitors, vaccines, chimeric antigen receptor T cells therapy, and nanomedicines.

Review of Contemporary Self-Assembled Systems for the Controlled Delivery of Therapeutics in Medicine

The novel and unique design of self-assembled micro and nanostructures can be tailored and controlled through the deep understanding of the self-assembly behavior of amphiphilic molecules. The most commonly known amphiphilic molecules are surfactants, phospholipids, and block copolymers. These molecules present a dual attraction in aqueous solutions that lead to the formation of structures like micelles, hydrogels, and liposomes. These structures can respond to external stimuli and can be further modified making them ideal for specific, targeted medical needs and localized drug delivery treatments. Biodegradability, biocompatibility, drug protection, drug bioavailability, and improved patient compliance are among the most important benefits of these self-assembled structures for drug delivery purposes. Furthermore, there are numerous FDA-approved biomaterials with self-assembling properties that can help shorten the approval pathway of efficient platforms, allowing them to reach the therapeutic market faster. This review focuses on providing a thorough description of the current use of self-assembled micelles, hydrogels, and vesicles (polymersomes/liposomes) for the extended and controlled release of therapeutics, with relevant medical applications. FDA-approved polymers, as well as clinically and commercially available nanoplatforms, are described throughout the paper.

Recent Advancement in Nanotechnology-Based Drug Delivery System Against Viral Infections

In the last few decades, the exponential rise in the incidence of viral infections sets a global health emergency across the world. The biomimetic architecture, the ability to hijack host immune responses, continuous antigen shifting, and drafting are the major critical factors that are responsible for the unavailability of a concrete therapeutic regimen against viral infections. Further, inappropriate pharmacodynamic physicochemical and biological parameters such as low aqueous solubility, poor permeability, high affinity for plasm proteins, short biological half-lives, and fast elimination from the systemic circulation are the major critical factors that govern the suboptimal drug concentration at the target site that leads to the development of drug resistance. To address this issue, nanotechnology-based drug delivery approach is emerged as an altering method to attain the optimal drug concentration at the target site for a prolonged period by integrating the nanoengineering tools in the synthesis of nanoparticles. Nanodimensional configuration with enhanced permeability and retention effect, increased surface-area-to-volume ratio, provision for surface functionalization, etc., are the privileged aspects that make it an effective drug delivery system for dispensing the antiviral therapeutics. However, size, shape, charge, and surface topology of nanoparticles are the greater influential factors that determine target-specific drug delivery, optimum cellular uptake, degree of opsonization by the host immune cells, drug retention time, transcytosis, the extension of biological half-life, in vivo stability, and cytotoxicity. The review will enlighten the elaborative role of nanotechnology-based drug delivery and the major challenging aspect of clinical safety and efficacy.

Liposomes as multifaceted delivery system in the treatment of osteoporosis

Introduction: Treatment of osteoporosis with the available drug formulations is still challenging due to multiple associated limitations such as chronic treatment, off-target side effects, poor bone targeting, and low bioavailability. Adopting advanced bone-targeted drug delivery strategies like liposomes is one of the safe and effective approaches for osteoporosis treatment.Areas covered: This review summarizes the applications of liposomes in gene delivery, bone regeneration, bone-targeted delivery, and as a carrier for drug encapsulation in the treatment of osteoporosis. Details of all the supportive studies are discussed here and the bone-specific roles of the strategies like new generation liposomes in osteoporosis are elaborated. The future scope of performing in-depth research on the bone-targeted liposomes is discussed.Expert opinion: Liposomes-based bone-targeted delivery of therapeutics seems to be a promising approach for the effective treatment of osteoporosis. But till date, the tremendous in vitro and in vivo research on liposomes has failed to attain significant progress in their clinical translation. From bench to bedside success of the research an interdisciplinary collaboration between the preclinical and clinical experts engaged at different stages of liposomes development is required.

Chronic Inflammatory Diseases, Anti-Inflammatory Agents and Their Delivery Nanosystems

Inflammatory diseases, whether caused by excessive stress on certain tissues/parts of the body or arising from infections accompanying autoimmune or secondary diseases, have become a problem, especially in the Western world today. Whether these are inflammations of visceral organs, joints, bones, or the like, they are always a physiological reaction of the body, which always tries to eradicate noxious agents and restore tissue homeostasis. Unfortunately, this often results in damage, often irreversible, to the affected tissues. Nevertheless, these inflammatory reactions of the body are the results of excessive stress, strain, and the generally unhealthy environment, in which the people of Western civilization live. The pathophysiology and pathobiochemistry of inflammatory/autoimmune processes are being studied in deep detail, and pharmaceutical companies are constantly developing new drugs that modulate/suppress inflammatory responses and endogenous pro-inflammatory agents. In addition to new specifically targeted drugs for a variety of pro-inflammatory agents, a strategy can be found for the use of older drugs, which are formulated into special nanodrug delivery systems with targeted distribution and often modified release. This contribution summarizes the current state of research and development of nanoformulated anti-inflammatory agents from both conventional drug classes and experimental drugs or dietary supplements used to alleviate inflammatory reactions.

Dendritic Polymers as Promising Additives for the Manufacturing of Hybrid Organoceramic Nanocomposites with Ameliorated Properties Suitable for an Extensive Diversity of Applications

As the field of nanoscience is rapidly evolving, interest in novel, upgraded nanomaterials with combinatory features is also inevitably increasing. Hybrid composites, offer simple, budget-conscious and environmental-friendly solutions that can cater multiple needs at the same time and be applicable in many nanotechnology-related and interdisciplinary studies. The physicochemical idiocrasies of dendritic polymers have inspired their implementation as sorbents, active ingredient carriers and templates for complex composites. Ceramics are distinguished for their mechanical superiority and absorption potential that render them ideal substrates for separation and catalysis technologies. The integration of dendritic compounds to these inorganic hosts can be achieved through chemical attachment of the organic moiety onto functionalized surfaces, impregnation and absorption inside the pores, conventional sol-gel reactions or via biomimetic mediation of dendritic matrices, inducing the formation of usually spherical hybrid nanoparticles. Alternatively, dendritic polymers can propagate from ceramic scaffolds. All these variants are covered in detail. Optimization techniques as well as established and prospected applications are also presented.

Radiolabeled Gold Nanoparticles for Imaging and Therapy of Cancer

In the Last decades, nanotechnology has provided novel and alternative methodologies and tools in the field of medical oncology, in order to tackle the issues regarding the control and treatment of cancer in modern society. In particular, the use of gold nanoparticles (AuNPs) in radiopharmaceutical development has provided various nanometric platforms for the delivery of medically relevant radioisotopes for SPECT/PET diagnosis and/or radionuclide therapy. In this review, we intend to provide insight on the methodologies used to obtain and characterize radiolabeled AuNPs while reporting relevant examples of AuNPs developed during the last decade for applications in nuclear imaging and/or radionuclide therapy, and highlighting the most significant preclinical studies and results.

Cancer Immunotherapy and Application of Nanoparticles in Cancers Immunotherapy as the Delivery of Immunotherapeutic Agents and as the Immunomodulators

Simple Summary

Cancer becomes one of the major public health problems globally and the burden is expected to be increasing. Currently, both the medical and research communities have attempted an approach to nonconventional cancer therapies that can limit damage or loss of healthy tissues and be able to fully eradicate the cancer cells. In the last few decades, cancer immunotherapy becomes an important tactic for cancer treatment. Immunotherapy of cancer must activate the host’s anti-tumor response by enhancing the innate immune system and the effector cell number, while, minimizing the host’s suppressor mechanisms. However, many immunotherapies are still limited by poor therapeutic targeting and unwanted side effects. Hence, a deeper understanding of tumor immunology and antitumor immune responses is essential for further improvement of cancer immunotherapy. In addition, effective delivery systems are required to deliver immunotherapeutic agents to the site of interest (such as: to Tumor microenvironments, to Antigen-Presenting Cells, and to the other immune systems) to enhance their efficacy by minimizing off-targeted and unwanted cytotoxicity.

Abstract

In the last few decades, cancer immunotherapy becomes an important tactic for cancer treatment. However, some immunotherapy shows certain limitations including poor therapeutic targeting and unwanted side effects that hinder its use in clinics. Recently, several researchers are exploring an alternative methodology to overcome the above limitations. One of the emerging tracks in this field area is nano-immunotherapy which has gone through rapid progress and revealed considerable potentials to solve limitations related to immunotherapy. Targeted and stimuli-sensitive biocompatible nanoparticles (NPs) can be synthesized to deliver immunotherapeutic agents in their native conformations to the site of interest to enhance their antitumor activity and to enhance the survival rate of cancer patients. In this review, we have discussed cancer immunotherapy and the application of NPs in cancer immunotherapy, as a carrier of immunotherapeutic agents and as a direct immunomodulator.

Drug Delivery Systems of Natural Products in Oncology

In recent decades, increasing interest in the use of natural products in anticancer therapy field has been observed, mainly due to unsolved drug-resistance problems. The antitumoral effect of natural compounds involving different signaling pathways and cellular mechanisms has been largely demonstrated in in vitro and in vivo studies. The encapsulation of natural products into different delivery systems may lead to a significant enhancement of their anticancer efficacy by increasing in vivo stability and bioavailability, reducing side adverse effects and improving target-specific activity. This review will focus on research studies related to nanostructured systems containing natural compounds for new drug delivery tools in anticancer therapies.

Recent Advances in Polymeric Nanoparticle-Encapsulated Drugs against Intracellular Infections

Polymeric nanocarriers (PNs) have demonstrated to be a promising alternative to treat intracellular infections. They have outstanding performance in delivering antimicrobials intracellularly to reach an adequate dose level and improve their therapeutic efficacy. PNs offer opportunities for preventing unwanted drug interactions and degradation before reaching the target cell of tissue and thus decreasing the development of resistance in microorganisms. The use of PNs has the potential to reduce the dose and adverse side effects, providing better efficiency and effectiveness of therapeutic regimens, especially in drugs having high toxicity, low solubility in the physiological environment and low bioavailability. This review provides an overview of nanoparticles made of different polymeric precursors and the main methodologies to nanofabricate platforms of tuned physicochemical and morphological properties and surface chemistry for controlled release of antimicrobials in the target. It highlights the versatility of these nanosystems and their challenges and opportunities to deliver antimicrobial drugs to treat intracellular infections and mentions nanotoxicology aspects and future outlooks.

Gold Nanoparticles for Vectorization of Nucleic Acids for Cancer Therapeutics

Cancer remains a complex medical challenge and one of the leading causes of death worldwide. Nanomedicines have been proposed as innovative platforms to tackle these complex diseases, where the combination of several treatment strategies might enhance therapy success. Among these nanomedicines, nanoparticle mediated delivery of nucleic acids has been put forward as key instrument to modulate gene expression, be it targeted gene silencing, interference RNA mechanisms and/or gene edition. These novel delivery systems have strongly relied on nanoparticles and, in particular, gold nanoparticles (AuNPs) have paved the way for efficient delivery systems due to the possibility to fine-tune their size, shape and surface properties, coupled to the ease of functionalization with different biomolecules. Herein, we shall address the different molecular tools for modulation of expression of oncogenes and tumor suppressor genes and discuss the state-of-the-art of AuNP functionalization for nucleic acid delivery both in vitro and in vivo models. Furthermore, we shall highlight the clinical applications of these spherical AuNP based conjugates for gene delivery, current challenges, and future perspectives in nanomedicine.

Gold Nanoparticles as Colorimetric Sensors for the Detection of DNA Bases and Related Compounds

Results regarding interaction of colloidal gold solutions with nucleobases, including uracil (U), as well as its sulfur derivatives, 2-thiouracil (2TU) and 4-thiouracil (4TU), cytosine (C), adenine (A), and guanine (G), as well as urea and thiourea (TU), are reported. Anionic stabilized citrate gold nanoparticles (AuNPs) were synthesized by reducing the tetrachloroaurate (III) trihydrate with trisodium citrate. The surface plasmon resonance (SPR) band was used in the characterization of synthesized AuNPs, as well as transmission electron microscope (TEM) imaging, which was used in the characterization of dispersed and aggregated gold nanoparticles. Interactions of nucleobases with the gold surface was analyzed by following the plasmon absorbance band red shift of the AuNPs. The sulfur-containing compounds adsorbed to the nanoparticle surfaces by chemisorption-type interactions; with TU and 4TU, the process is accompanied by a sudden change in color; in contrast, 2TU forms stable functionalized gold nanoparticles. Urea and U do not adsorb to nanoparticle surfaces, but the other heterocyclic bases containing nitrogen interact effectively with the gold surface, causing the assembly of nanoparticles, even though the interparticle self-aggregation process was slower than that mediated by either TU or 4TU. The method is efficient in the colorimetric detection of nucleobases and derivatives at concentration levels on the order of 1 µM.

Niosomal Drug Delivery Systems for Ocular Disease-Recent Advances and Future Prospects

The eye is a complex organ consisting of several protective barriers and particular defense mechanisms. Since this organ is exposed to various infections, genetic disorders, and visual impairments it is essential to provide necessary drugs through the appropriate delivery routes and vehicles. The topical route of administration, as the most commonly used approach, maybe inefficient due to low drug bioavailability. New generation safe, effective, and targeted drug delivery systems based on nanocarriers have the capability to circumvent limitations associated with the complex anatomy of the eye. Nanotechnology, through various nanoparticles like niosomes, liposomes, micelles, dendrimers, and different polymeric vesicles play an active role in ophthalmology and ocular drug delivery systems. Niosomes, which are nano-vesicles composed of non-ionic surfactants, are emerging nanocarriers in drug delivery applications due to their solution/storage stability and cost-effectiveness. Additionally, they are biocompatible, biodegradable, flexible in structure, and suitable for loading both hydrophobic and hydrophilic drugs. These characteristics make niosomes promising nanocarriers in the treatment of ocular diseases. Hereby, we review niosome based drug delivery approaches in ophthalmology starting with different preparation methods of niosomes, drug loading/release mechanisms, characterization techniques of niosome nanocarriers and eventually successful applications in the treatment of ocular disorders.