Fixed-diameter upconversion nanorods with controllable length and their interaction with cells

A series of NaYF₄: Yb, Er upconversion nanorods with fixed diameter and controllable length were synthesized by the injection of sodium trifluoroacetate (CF₃COONa) mixed with potassium trifluoroacetate (CF₃COOK) precursor into a heated solution of ligand. We found that with the increased percentage of CF₃COOK, the length of resultant nanorods was increased from ∼40 nm to ∼200 nm whilst the diameter was kept in a narrow range of 37-42 nm. The elongation of nanorods was attributed to the specific absorption of sodium oleate on the prismatic facets, and the integration of potassium ions into the lattice as well. We further found that the elongated length affected the relative fluorescence intensity between red and green emission. More importantly, with fixed diameter, the cellular uptake of nanorods was found decreasing with the increase of their length. Meanwhile the decrease of diameter resulted in an increased cellular uptake. These results were attributed to both specific surface area and possibly varied contacting angle between nanorods and cell membrane. The current work not only suggested a synthetic method for the precise control of upconversion nanorods, but also shed light on the design of nanocrystals for cell-related biomedical applications.

Bile Acid-Based Drug Delivery Systems for Enhanced Doxorubicin Encapsulation: Comparing Hydrophobic and Ionic Interactions in Drug Loading and Release

Doxorubicin (Dox) is a drug of choice in the design of drug delivery systems directed toward breast cancers, but is often limited by loading and control over its release from polymer micelles. Bile acid-based block copolymers present certain advantages over traditional polymer-based systems for drug delivery purposes, since they can enable a higher drug loading via the formation of a reservoir through their aggregation process. In this study, hydrophobic and electrostatic interactions are compared for their influence on Dox loading inside cholic acid based block copolymers. Poly(allyl glycidyl ether) (PAGE) and poly(ethylene glycol) (PEG) were grafted from the cholic acid (CA) core yielding a star-shaped block copolymer with 4 arms (CA-(PAGE- b-PEG)₄) and then loaded with Dox via a nanoprecipitation technique. A high Dox loading of 14 wt % was achieved via electrostatic as opposed to hydrophobic interactions with or without oleic acid as a cosurfactant. The electrostatic interactions confer a pH responsiveness to the system. 50% of the loaded Dox was released at pH 5 in comparison to 12% at pH 7.4. The nanoparticles with Dox loaded via hydrophobic interactions did not show such a pH responsiveness. The systems with Dox loaded via electrostatic interactions showed the lowest IC₅₀ and highest cellular internalization, indicating the pre-eminence of this interaction in Dox loading. The blank formulations are biocompatible and did not show cytotoxicity up to 0.17 mg/mL. The new functionalized star block copolymers based on cholic acid show great potential as drug delivery carriers.

Shape-Dependent Dissolution and Cellular Uptake of Silver Nanoparticles

The cellular uptake and dissolution of trigonal silver nanoprisms (edge length 42 ± 15 nm, thickness 8 ± 1 nm) and mostly spherical silver nanoparticles (diameter 70 ± 25 nm) in human mesenchymal stem cells (hMSC's) and human keratinocytes (HaCaT cells) were investigated. Both particles are stabilized by polyvinylpyrrolidone (PVP), with the prisms additionally stabilized by citrate. The nanoprisms dissolved slightly in pure water but strongly in isotonic saline or at pH 4, corresponding to the lowest limit for the pH during cellular uptake. The tips of the prisms became rounded within minutes due to their high surface energy. Afterward, the dissolution process slowed down due to the presence of both PVP stabilizing Ag{100} sites and citrate blocking Ag{111} sites. On the contrary, nanospheres, solely stabilized by PVP, dissolved within 24 h. These results correlate with the finding that particles in both cell types have lost >90% of their volume within 24 h. hMSC's took up significantly more Ag from nanoprisms than from nanospheres, whereas HaCaT cells showed no preference for one particle shape. This can be rationalized by the large cellular interaction area of the plateletlike nanoprisms and the bending stiffness of the cell membranes. hMSC's have a highly flexible cell membrane, resulting in an increased uptake of plateletlike particles. HaCaT cells have a membrane with a 3 orders of magnitude higher Young's modulus than for hMSC. Hence, the energy gain due to the larger interaction area of the nanoprisms is compensated for by the higher energy needed for cell membrane deformation compared to that for spheres, leading to no shape preference.

In vitro assessment of silver nanoparticles immunotoxicity

This study aimed to characterize unwanted immune effects of nanoparticles (NP) using THP-1 cells, human whole blood and enriched peripheral blood monocytes. Commercially available silver NP (AgNP < 100 nm, also confirmed by Single Particle Extinction and Scattering) were used as prototypical NP. Cells were treated with AgNP alone or in combination with classical immune stimuli (i.e. LPS, PHA, PWM) and cytokine assessed; in addition, CD54 and CD86 expression was evaluated in THP-1 cells. AgNP alone induced dose-related IL-8 production in all models, with higher response observed in THP-1 cells, possibly connected to different protein corona formation in bovine versus human serum. AgNP potentiated LPS-induced IL-8 and TNF-α, but not LPS-induced IL-10. AgNP alone induced slight increase in IL-4, and no change in IFN-γ production. While responses to PHA in term of IL-4 and IFN-γ production were not affected, increased PWM-induced IL-4 and IFN-γ production were observed, suggesting potentiation of humoral response. Reduction in PHA-induced IL-10 was observed. Overall, results indicate immunostimulatory effects. THP-1 cells work as well as primary cells, representing a useful and practical alternative, with the awareness that from a physiological point of view the whole blood assay is the one that comes closest to reality.

Metal assisted self-assembled rod like nanostructures for effective cellular internalization

This work describes a metal assisted self-assembled rod like nanostructure which can be used for the delivery of therapeutic agents.

Impact of Cross-Linker Valency on Gold Nanoparticle Aggregate Formation and Cellular Uptake

Synthesis of spherical, biocompatible nanoparticle aggregates using a small molecular cross-linker is a simple and flexible approach for the controlled assembly of gold nanoparticles. This strategy can be extended to a variety of cross-linkers, making it possible to the test the effect of cross-linker properties on aggregate formation and physicochemical properties. Here, we synthesized aggregates using a series of structurally homologous cross-linkers with differing valencies. These aggregates have the same size, morphology, surface charge, surface coating, and stability in salt, media, and low pH conditions, but they differ in their stability to cyanide etching and uptake by cells. This highlights the fine-tuning of nanoparticle aggregate properties that can be achieved by using small-molecule cross-linkers.

The Diverse Range of Possible Cell Membrane Interactions with Substrates: Drug Delivery, Interfaces and Mobility

The cell membrane has gained significant attention as a platform for the development of bio-inspired nanodevices due to its immune-evasive functionalities and copious bio-analogs. This review will examine several uses of cell membranes such as (i) therapeutic delivery carriers with or without substrates (i.e., nanoparticles and artificial polymers) that have enhanced efficiency regarding copious cargo loading and controlled release, (ii) exploiting nano-bio interfaces in membrane-coated particles from the macro- to the nanoscales, which would help resolve the biomedical issues involved in biological interfacing in the body, and (iii) its effects on the mobility of bio-moieties such as lipids and/or proteins in cell membranes, as discussed from a biophysical perspective. We anticipate that this review will influence both the development of novel anti-phagocytic delivery cargo and address biophysical problems in soft and complex cell membrane.

Investigating metabolic regulation using targeted neuromodulation

The central nervous system (CNS) plays a vital role in regulating energy balance and metabolism. Over the last 50 years, studies in animal models have allowed us to identify critical CNS regions involved in these processes and even crucial cell populations. Now, techniques for genetically and anatomically targeted manipulation of specific neural populations using light (optogenetic), ligands (chemogenetic), or magnetic fields (radiogenetic/magnetogenetic) allow detailed investigation of circuits involved in metabolic regulation. In this review, we provide a brief overview of recent studies using light- and magnetic field-regulated neural activity to investigate the neural circuits contributing to metabolic control.

ζ potential changing nanoparticles as cystic fibrosis transmembrane conductance regulator gene delivery system: an in vitro evaluation

Aim: Aim of the study was the development of ζ potential changing nanoparticles as gene delivery system for the cystic fibrosis transmembrane conductance regulator gene. Methods: Chitosan and carboxymethyl cellulose were modified with phosphotyrosine, a substrate for the brush border enzyme alkaline phosphatase. With these synthesized derivatives, different nanoparticle formulations, including the cystic fibrosis transmembrane conductance regulator gene were prepared by ionic gelation. Results: A change from negative to positive ζ potential after enzymatic cleavage could be observed. Transfection studies with HEK-293 and Caco-2 cells showed transfection rates comparable to Lipofectamine 2000. Transfection efficiencies were significantly decreased when phosphate cleavage and thus ζ potential change was inhibited by phosphatase inhibitor. Conclusion: The developed nanoparticles represent a promising gene delivery system.

Cytotoxicological pathways induced after nanoparticle exposure: studies of oxidative stress at the 'nano-bio' interface

Nanotechnology is advancing rapidly; many industries are utilizing nanomaterials because of their remarkable properties. As of 2017, over 1800 "nano-enabled products" (i.e. products that incorporate a nanomaterial feature and alter the product's performance) have been used to revolutionize pharmaceutical, transportation, and agriculture industries, just to name a few. As the number of nano-enabled products continues to increase, the risk of nanoparticle exposure to humans and the surrounding environment also increases. These exposures are usually classified as either intentional or unintentional. The increased rate of potential nanoparticle exposure to humans has required the field of 'nanotoxicology' to rapidly screen for key biological, biochemical, chemical, or physical signals, signatures, or markers associated with specific toxicological pathways of injury within in vivo, in vitro, and ex vivo models. One of the common goals of nanotoxicology research is to identify critical perturbed biological pathways that can lead to an adverse outcome. This review focuses on the most common toxicological pathways induced by nanoparticle exposure and provides insights into how these perturbations could aid in the development of nanomaterial specific adverse outcomes, inform nano-enabled product development, ensure safe manufacturing practices, promote intentional product use, and avoid environmental health hazards.

Overviews on the cellular uptake mechanism of polysaccharide colloidal nanoparticles

Nanoparticulate drug/gene carriers have gained much attention in the past decades because of their versatile and tunable properties. However, efficacy of the therapeutic agents can be further enhanced using naturally occurring materials-based nanoparticles. Polysaccharides are an emerging class of biopolymers; therefore, they are generally considered to be safe, non-toxic, biocompatible and biodegradable. Considering that the target of nanoparticle-based therapeutic strategies is localization of biomedical agents in subcellular compartments, a detailed understanding of the cellular mechanism involved in the uptake of polysaccharide-based nanoparticles is essential for safe and efficient therapeutic applications. Uptake of the nanoparticles by the cellular systems occurs with a process known as endocytosis and is influenced by the physicochemical characteristics of nanoparticles such as size, shape and surface chemistry as well as the employed experimental conditions. In this study, we highlight the main endocytosis mechanisms responsible for the cellular uptake of polysaccharide nanoparticles containing drug/gene.

Deformable Nanovesicles Synthesized through an Adaptable Microfluidic Platform for Enhanced Localized Transdermal Drug Delivery

Phospholipid-based deformable nanovesicles (DNVs) that have flexibility in shape offer an adaptable and facile method to encapsulate diverse classes of therapeutics and facilitate localized transdermal delivery while minimizing systemic exposure. Here we report the use of a microfluidic reactor for the synthesis of DNVs and show that alteration of input parameters such as flow speeds as well as molar and flow rate ratios increases entrapment efficiency of drugs and allows fine-tuning of DNV size, elasticity, and surface charge. To determine the ability of DNV-encapsulated drug to be delivered transdermally to a local site, we synthesized, characterized, and tested DNVs carrying the fluorescently labeled hydrophilic bisphosphonate drug AF-647 zoledronate (AF647-Zol). AF647-Zol DNVs were lyophilized, resuspended, and applied topically as a paste to the calvarial skin of mice. High-resolution fluorescent imaging and confocal microscopy revealed significant increase of encapsulated payload delivery to the target tissue-cranial bone-by DNVs as compared to nondeformable nanovesicles (NVs) or aqueous drug solutions. Interestingly, NV delivery was not superior to aqueous drug solution. Our studies show that microfluidic reactor-synthesized DNVs can be produced in good yield, with high encapsulation efficiency, reproducibility, and stability after storage, and represent a useful vehicle for localized transdermal drug delivery.

Rabies Virus-Inspired Silica-Coated Gold Nanorods as a Photothermal Therapeutic Platform for Treating Brain Tumors

Rabies virus-inspired silica-coated gold nanorods are fabricated by mimicking size, shape, surface glycoprotein property and in vivo behavior of the rabies virus. These nanorods not only resemble the appearance of the actual rabies virus but also travel into the brain through the neuronal pathway bypassing the blood-brain barrier, and moreover respond to near-infrared laser (808 nm) irradiation, emit heat, and effectively suppress brain tumors.

Functionalized graphene oxide for anti-VEGF siRNA delivery: preparation, characterization and evaluation in vitro and in vivo

GO–PLL–SDGR/VEGF-siRNA inhibits tumor growth as a tumor targeting delivery system.

Development of a nanoprecipitation method for the entrapment of a very water soluble drug into Eudragit RL nanoparticles

Rivastigmine hydrogen tartrate (RHT), one of the potential cholinesterase inhibitors, has received great attention as a new drug candidate for the treatment of Alzheimer's disease. However, the bioavailability of RHT from the conventional pharmaceutical forms is low because of the presence of the blood brain barrier. The main aim of the present study was to prepare positively charged Eudragit RL 100 nanoparticles as a model scaffold for providing a sustained release profile for RHT. The formulations were evaluated in terms of particle size, zeta potential, surface morphology, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC). Drug entrapment efficiency and in vitro release properties of lyophilized nanoparticles were also examined. The resulting formulations were found to be in the size range of 118 nm to 154 nm and zeta potential was positive (+22.5 to 30 mV). Nanoparticles showed the entrapment efficiency from 38.40 ± 8.94 to 62.00 ± 2.78%. An increase in the mean particle size and the entrapment efficiency was observed with an increase in the amount of polymer. The FTIR, XRD, and DSC results ruled out any chemical interaction between the drug and Eudragit RL100 polymer. RHT nanoparticles containing low ratio of polymer to drug (4:1) presented a faster drug release and on the contrary, nanoparticles containing high ratio of polymer to drug (10:1) were able to give a more sustained release of the drug. The study revealed that RHT nanoparticles were capable of releasing the drug in a prolonged period of time and increasing the drug bioavailability.

Cisplatin and valproate released from the bifunctional [Pt(IV)Cl2(NH3)2(valproato)2] antitumor prodrug or from liposome formulations: who does what?

Comparison between the antiproliferative properties of a Pt(iv)-valproato complex and its metabolites indicates that the former is more active because it is unremoved from cells.

3D nano- and micro-patterning of biomaterials for controlled drug delivery

Recently, there has been an emerging interest in controlling 3D structures and designing novel 3D shapes for drug carriers at nano- and micro-scales. Certain 3D shapes and structures of drug particles enable transportation of the drugs to desired areas of the body, allow drugs to target specific cells and tissues, and influence release kinetics. Advanced nano- and micro-manufacturing methods including 3D printing, photolithography-based processes, microfluidics and DNA origami have been developed to generate defined 3D shapes and structures for drug carriers. This paper reviews the importance of 3D structures and shapes on controlled drug delivery, and the current state-of-the-art technologies that allow the creation of novel 3D drug carriers at nano- and micro-scales.

Renal Clearable Organic Nanocarriers for Bioimaging and Drug Delivery

Renally cleared zwitterionic nanocarriers (H-Dots) are composed of ε-polylysine backbone for charge variations, near-infrared fluorophores for bioimaging, and β-cyclodextrins for potential drug delivery. H-Dots show ideal systemic circulation and rapid distribution and excrete from normal tissue/organ via renal excretion after complete targeting to the tumor site without nonspecific uptake by the immune system.

Polyanionic Biopolymers for the Delivery of Pt(II) Cationic Antiproliferative Complexes

Phenanthriplatin, that is, (SP-4-3)-diamminechlorido(phenanthridine)platinum(II) nitrate, an effective antitumor cationic Pt(II) complex, was loaded on negatively charged dextran sulfate (DS) as a model vector for drug delivery via electrostatic interactions. The free complex and the corresponding conjugate with DS were tested on two standard human tumor cell lines, namely, ovarian A2780 and colon HCT 116, and on several malignant pleural mesothelioma cell lines (namely, epithelioid BR95, mixed/biphasic MG06, sarcomatoid MM98, and sarcomatoid cisplatin-resistant MM98R). The in vitro results suggest that the conjugate releases the active metabolite phenanthriplatin with a biphasic fashion. In these experimental conditions, the conjugate is slightly less active than free phenanthriplatin; but both exhibited antiproliferative potency higher than the reference metallodrug cisplatin and were able to overcome the acquired cisplatin chemoresistance in MM98R cells.

Aqueous synthesized quantum dots interfere with the NF-κB pathway and confer anti-tumor, anti-viral and anti-inflammatory effects

The NF-κB pathway plays crucial roles in inflammatory responses and cell survival. Aberrant constitutive NF-κB activation is associated with various human diseases including cancer and inflammatory and auto-immune diseases. Consequently, it is highly desirable to develop new kinds of inhibitors, which are highly efficacious for blocking the NF-κB pathway. In this study, by using a typical kind of aqueous synthesized quantum dots (QDs), i.e., CdTe QDs, as a model, we for the first time demonstrated that the QDs could selectively affect the cellular nuclear factor-κB (NF-κB) signaling pathway, but do not affect the AKT or ERK pathways. Typically, the QDs efficiently inhibited the activation of IKKα and IKKβ, resulting in the suppression of both the canonical and the non-canonical NF-κB signaling pathways. Inhibition of NF-κB by QDs downregulates anti-apoptotic genes and promotes apoptosis in cancer cells. The QDs induced NF-κB inhibition and cytotoxicity could be blocked by N-acetylcysteine due to the reduced cellular uptake of QDs. Importantly, inhibition of NF-κB by QDs displayed promising effects against the viral replication and in vivo bacterial endotoxin-induced inflammatory responses. These data suggest the QDs as potent inhibitors of the NF-κB signaling pathway, both in vitro and in vivo. Our findings highlight the potential of using QDs in the development of anti-cancer, anti-viral, and anti-inflammatory approaches, and also facilitate better understanding of QDs-related cellular behavior under the molecular level.

Hydrogel nanoparticles and nanocomposites for nasal drug/vaccine delivery

Over the past few years, nasal drug delivery has attracted more and more attentions, and been recognized as the most promising alternative route for the systemic medication of drugs limited to intravenous administration. Many experiments in animal models have shown that nanoscale carriers have the ability to enhance the nasal delivery of peptide/protein drugs and vaccines compared to the conventional drug solution formulations. However, the rapid mucociliary clearance of the drug-loaded nanoparticles can cause a reduction in bioavailability percentage after intranasal administration. Thus, research efforts have considerably been directed towards the development of hydrogel nanosystems which have mucoadhesive properties in order to maximize the residence time, and hence increase the period of contact with the nasal mucosa and enhance the drug absorption. It is most certain that the high viscosity of hydrogel-based nanosystems can efficiently offer this mucoadhesive property. This update review discusses the possible benefits of using hydrogel polymer-based nanoparticles and hydrogel nanocomposites for drug/vaccine delivery through the intranasal administration.

Size-Shifting Micelle Nanoclusters Based on a Cross-Linked and pH-Sensitive Framework for Enhanced Tumor Targeting and Deep Penetration Features

The antitumor effect of chemotherapeutics loaded micelles mainly depends on two aspects: the accumulation in the tumor region and the penetration into the tumor interior. These two processes have different demands on particle size. The optimal particle size for enhanced permeability and retention (EPR) is commonly believed to be around 100 nm, while much smaller size is desired for deeper penetration into the tumor interior. To address these two different requirements, we constructed size-shifting micelle nanoclusters (MNC) based on a cross-linked framework interspersed with micelles. The particle size of the micelles was 14.6 ± 0.8 nm and increased to 104.2 ± 8.1 nm after the MNC were formed, leading to an effective utilization of the EPR effect. MNC were shifted to independent micelles in lysosomes, so that a more favorable particle size for penetration could be realized. The results of antitumor growth in vivo demonstrated that size-shifting MNC were more beneficial for tumor therapy than micelles.

Cell cycle dependent cellular uptake of zinc oxide nanoparticles in human epidermal cells

Metal oxide nanoparticles (NPs), including zinc oxide (ZnO) NPs have shown success for use as vehicles for drug delivery and targeting gene delivery in many diseases like cancer. Current anticancer chemotherapeutics fail to effectively differentiate between cancerous and normal cells. There is an urgent need to develop novel drug delivery system that can better target cancer cells while sparing normal cells and tissues. Particularly, ZnO NPs exhibit a high degree of cancer cell selectivity and induce cell death, oxidative stress, interference with the cell cycle progression and genotoxicity in cancerous cells. In this scenario, effective cellular uptake of NP seems to be crucial, which is shown to be affected by cell cycle progression. In the present study, the cytotoxic potential of ZnO NPs and the effect of different cell cycle phases on the uptake of ZnO NPs were examined in A431 cells. It is shown that the ZnO NPs led to cell death and reactive oxygen species generation and were able to induce cell cycle arrest in S and G2/M phase with the higher uptake in G2/M phase compared with other phases.

A General Strategy for Facile Synthesis and In Situ Screening of Self-Assembled Polymer-Peptide Nanomaterials

A universal strategy for efficient, mild, and purification-free synthesis and in situ screening of functional polymer-peptide nanomaterials is described. More than 1000 polymer-peptide conjugates (PPCs) with various chemical structures, compositions, and therapeutic efficacy are created. According to this strategy, the structure-function relationship of the PPCs is revealed, and the antitumor efficacies of the top performing PPCs are evaluated in vivo.

Functionalized nonporous silica nanoparticles as carriers for Pt(iv) anticancer prodrugs

Conjugate Pt(iv)–silica nanoparticles exhibited better antiproliferative activity than cisplatin and Pt(iv) precursors, due to their more efficient cellular uptake.

Negatively charged gold nanoparticles as a dexamethasone carrier: stability in biological media and bioactivity assessment in vitro

AuNP and AuNP/DXM stability and drug release kinetics in different biological media.

Pharmacokinetics, pharmacodynamics and toxicology of theranostic nanoparticles

Nanoparticles (NPs) are considered a promising tool in both diagnosis and therapeutics. Theranostic NPs possess the combined properties of targeted imaging and drug delivery within a single entity. While the categorization of theranostic NPs is based on their structure and composition, the pharmacokinetics of NPs are significantly influenced by the physicochemical properties of theranostic NPs as well as the routes of administration. Consequently, altered pharmacokinetics modify the pharmacodynamic efficacy and toxicity of NPs. Although theranostic NPs hold great promise in nanomedicine and biomedical applications, a lack of understanding persists on the mechanisms of the biodistribution and adverse effects of NPs. To better understand the diagnostic and therapeutic functions of NPs, this review discusses the factors that influence the pharmacokinetics, pharmacodynamics and toxicology of theranostic NPs, along with several strategies for developing novel diagnostic and therapeutic modalities.

Effects of the physicochemical properties of gold nanostructures on cellular internalization

Unique physicochemical properties of Au nanomaterials make them potential star materials in biomedical applications. However, we still know a little about the basic problem of what really matters in fabrication of Au nanomaterials which can get into biological systems, especially cells, with high efficiency. An understanding of how the physicochemical properties of Au nanomaterials affect their cell internalization is of significant interest. Studies devoted to clarify the functions of various properties of Au nanostructures such as size, shape and kinds of surface characteristics in cell internalization are under way. These fundamental investigations will give us a foundation for constructing Au nanomaterial-based biomedical devices in the future. In this review, we present the current advances and rationales in study of the relationship between the physicochemical properties of Au nanomaterials and cell uptake. We also provide a perspective on the Au nanomaterial-cell interaction research.

Nanoparticles for antimicrobial purposes in Endodontics: A systematic review of in vitro studies

INTRODUCTION

Antimicrobial nanoparticles with enhanced physiochemical properties have attracted attention as modern antimicrobials, especially in the complicated oral cavity environment. The goal of the present article is to review the current state of nanoparticles used for antimicrobial purposes in root canal infections.

METHODS

A review was conducted in electronic databases using MeSH keywords to identify relevant published literature in English. The analysis and eligibility criteria were documented according to the Preferred Reporting Items for Systematic Reviews and Meta Analysis (PRISMA-guidelines). No restrictions on publication date were imposed. Data regarding root canal disinfections, general antimicrobial mechanisms of nanoparticles, type of nanoparticles as antimicrobial agent and antimicrobial effect of nanoparticles in endodontics were collected and subjected to descriptive data analysis.

RESULTS

The literature search in electronic databases according to the inclusion criteria provided 83 titles and abstracts. Among them 15 papers were related to antimicrobial effect of nanoparticles in Endodontics. Silver nanoparticles with sustainable activity were the most studied agent for its antimicrobial behavior in root canal infection. Aided polymeric nanoparticles with photo or ultrasound, glass bioactive nanoparticles as well as Calcium derivative based nanoparticles, with improved activity in comparison with the non-nano counterparts, are of importance in infection control of dental root canal. Bioactive Non-organic nanoparticles with structural capabilities present enhanced antimicrobial activity in root canal infections.

DISCUSSION

All included studies showed an enhanced or at least equal effect of nanoparticulate systems to combat dental root canal infections compared to conventional antimicrobial procedures. However, it is crucial to understand their shortcomings and their probable cellular effects and toxicity as well as environmental effects.