Independent effect of polymeric nanoparticle zeta potential/surface charge, on their cytotoxicity and affinity to cells

Evaluation of In Vitro Cytotoxic, Genotoxic, Apoptotic, and Cell Cycle Arrest Potential of Iron-Nickel Alloy Nanoparticles

The use of iron-nickel alloy nanoparticles (Fe-Ni ANPs) is increasing daily in various fields. People are increasingly exposed to these nanoparticles for occupational and environmental reasons. Our study determined some of the effects of Fe-Ni ANP exposure and impacts on human health at the cellular level. The cytotoxic and genotoxic potentials of Fe-Ni ANPs were investigated by XTT, clonogenic, comet, and GammaH2AX analyses using Beas-2B cells. Annexin V, multicaspase, and cell cycle arrest methods were used to understand the apoptotic mechanism of action. The intracellular ROS method was used to determine the primary mechanism that leads to cytotoxic and genotoxic activity. The Fe-Ni ANPs showed cytotoxic activity with the XTT and clonogenic methods: they had genotoxic potential, as demonstrated via genotoxicity methods. It was determined that the cytotoxic effect was realized by the caspase-dependent apoptotic pathway, and the cells were stopped at the G0/G1 stage by Fe-Ni ANPs. Increased intracellular ROS due to Fe-Ni ANPs led to cytotoxic, genotoxic, and apoptotic activity. Potential risks to human health due to Fe-Ni ANPs were then demonstrated at the cellular level.

Utilization of Olive Pomace in Green Synthesis of Selenium Nanoparticles: Physico-Chemical Characterization, Bioaccessibility and Biocompatibility

Olive pomace extract (OPE) was investigated as a potential surface modifier for the development of the green synthesis process of selenium nanoparticles (SeNPs). In order to evaluate them as potential nutraceuticals, the obtained nanosystems were characterized in terms of size distribution, shape, zeta potential, stability in different media, gastrointestinal bioaccessibility and biocompatibility. Systems with a unimodal size distribution of spherical particles were obtained, with average diameters ranging from 53.3 nm to 181.7 nm, depending on the type of coating agent used and the presence of OPE in the reaction mixture. The nanosystems were significantly affected by the gastrointestinal conditions. Bioaccessibility ranged from 33.57% to 56.93% and it was significantly increased by functionalization of with OPE. Biocompatibility was investigated in the HepG2 and Caco2 cell models, proving that they had significantly lower toxicity in comparison to sodium selenite. Significant differences were observed in cellular responses depending on the type of cells used, indicating differences in the mechanisms of toxicity induced by SeNPs. The obtained results provide new insight into the possibilities for the utilization of valuable food-waste extracts in the sustainable development of nanonutraceuticals.

Mesoporous silica size, charge, and hydrophobicity affect the loading and releasing performance of lambda-cyhalothrin

Nanopesticides are attracting increasing attention as a promising technology in agriculture to improve insecticidal efficacy, decrease pesticides uses, and reduce potential environmental impacts. We synthesized mesoporous silica nanoparticles, i.e., Mobil Composition of Matter No.48 (MCM-48), with different sizes (63-130 nm), charges (-22 to 12 mV), and hydrophobicity (water contact angle 29-103°) to assess their loading amount and release of a typical poorly soluble halogenated pyrethroid (i.e., lambda-cyhalothrin particles, LCNS). The smallest MCM-48 displayed relatively higher loading amount of LCNS (~16%) compared to the larger MCM-48 nanoparticles, likely because of its higher pore volume (1.46 cm³ g^-1) and pore size (3.56 nm). LCNS loading amount was further improved to ~26% and ~36% after -NH₂ (positively charged) and -CH₃ (hydrophobic) functionalization, respectively, probably due to hydrogen bonding, electrostatic, and hydrophobic interactions with LCNS. Loading LCNS in MCM-48 nanoparticles also significantly improved its dispersion in water and ultraviolet (UV) light stability, with a 3-7 times longer half-life than that of free LCNS. Although the -NH₂ and -CH₃ modifications of MCM-48 slightly decreased the UV stability of LCNS, they significantly decreased the release efficiency of LCNS, possibly because of their stronger interactions with LCNS. In addition, the insecticidal effects of LCNS-loaded MCM-48 were more efficient and longer than those of free LCNS. The findings clarify the relationships between physicochemical properties and performance of mesoporous silica nanoparticles, and will inform the rational design of materials for controlled release of pesticides and sustainable control of pests.

Potential Method of Autophagy Imaging with Cationized Gelatin Nanospheres Incorporating Molecular Beacon

The objective of this research is to develop an imaging method with cationized gelatin nanospheres incorporating molecular beacon (cGNS_MB) to visualize an autophagy activity in living cells. Cationized gelatin nanospheres (cGNS) were prepared by the conventional coacervation method, and then molecular beacon (MB) was incorporated into them. The cGNS_MB prepared were internalized into cells at a high efficiency. In this study, a starvation medium of serum and amino acids-free was used to induce autophagy. The autophagy activity was confirmed by an immunofluorescence staining for microtubule-associated proteins light chain 3B (LC3B) of an autophagy specific protein. With the autophagy induction time, the number of LC3 fluorescent dots increased, which indicated an increased autophagy activity. As the autophagy-related genes, sequestosome 1 (SQSTM1) and cathepsin F (CTSF), which up-regulate after autophagy induction, were chosen as the targets of cGNS_MB. The fluorescence intensity of cGNS_MB targeting to SQSTM1 and CTSF increased with the starvation treatment time, which well corresponded with the gene expression results. When applied to cells in different autophagy conditions, the cGNS_MB visualized the autophagy activity corresponding with the autophagy condition of cells. From the results obtained, it was concluded that the cGNS_MB provide a promising method to visualize the autophagy of cells. The advantage of cGNS_MB visualization is to obtain the temporal and spatial information without destroying sample cells.

Trends in the Design and Evaluation of Polymeric Nanocarriers: The In Vitro Nano-Bio Interactions

Different types of natural and synthetic polymeric nanocarriers are being tested for diverse biomedical applications ranging from drug/gene delivery vehicles to imaging probes. The development of such innovative nanoparticulate systems (NPs) should include in the very beginning of their conception a comprehensive evaluation of the nano-bio interactions. Specifically, intrinsic physicochemical properties as size, surface charge and shape may have an impact on cellular uptake, intracellular trafficking, exocytosis and cyto- or genocompatibility. Those properties can be tuned for effectiveness purposes such as targeting intracellular organelles, but at the same time inducing unforeseen adverse nanotoxicological effects. Further, those properties may change due to the adsorption of biological components (e.g. proteins) with a tremendous impact on the cellular response. The evaluation of these NPs is highly challenging and has produced some controversial results. Future research work should focus on the standardization of analytical or computational methodologies, aiming the identification of toxicity trends and the generation of a useful meta-analysis database on polymeric nanocarriers.This chapter covers all the aforementioned aspects, emphasizing the importance of the in vitro cellular studies in the first stages of polymeric nanocarriers development.

Antimicrobial benefits of flavonoids and their nanoformulations

Abstract:

Nowadays, there is an urgent need to discover and develop long-term and effective antimicrobial and biofilm-inhibiting compounds. Employing combination therapies using novel drug delivery systems and also natural antimicrobial substances is a promising strategy in this field. Nanoparticles (NPs)-based materials have become well appreciated in recent times due to serve as antimicrobial agents or the carriers for promoting the bioavailability and effectiveness of antibiotics. Flavonoids belong to the promising groups of bioactive compounds abundantly found in fruits, vegetables, spices, and medicinal plants with strong antimicrobial features. Flavonoids and NPs have potential as alternatives to the conventional antimicrobial agents, both on their own as well as in combination. Different classes of flavonoid NPs may be particularly advantageous in handling microbial infections. The most important antimicrobial mechanisms of flavonoid NPs include oxidative stress induction, non-oxidative mechanisms, and metal ion release. However, the efficacy of flavonoid NPs against pathogens and drug-resistant pathogens changes according to their physicochemical characteristics as well as the particular structure of microbial cell wall and enzymatic composition. In this review, we provide an outlook on the antimicrobial mechanism of flavonoid-based NPs and the crucial factors that are involved.

From properties to toxicity: Comparing microplastics to other airborne microparticles

Microplastic (MP) debris is considered as a potentially hazardous material. It is omnipresent in our environment, and evidence that MP is also abundant in the atmosphere is increasing. Consequently, the inhalation of these particles is a significant exposure route to humans. Concerns about potential effects of airborne MP on human health are rising. However, currently, there are not enough studies on the putative toxicity of airborne MP to adequately assess its impact on human health. Therefore, we examined potential drivers of airborne MP toxicity. Physicochemical properties like size, shape, ζ-potential, adsorbed molecules and pathogens, and the MP's bio-persistence have been proposed as possible drivers of MP toxicity. Since their role in MP toxicity is largely unknown, we reviewed the literature on toxicologically well-studied non-plastic airborne microparticles (asbestos, silica, soot, wood, cotton, hay). We aimed to link the observed health effects and toxicology of these microparticles to the abovementioned properties. By comparing this information with studies on the effects of airborne MP, we analyzed possible mechanisms of airborne MP toxicity. Thus, we provide a basis for a mechanistic understanding of airborne MP toxicity. This may enable the assessment of risks associated with airborne MP pollution, facilitating effective policymaking and product design.

Resveratrol Microencapsulation into Electrosprayed Polymeric Carriers for the Treatment of Chronic, Non-Healing Wounds

Chronic, non-healing wounds represent a challenging socio-economic burden, demanding innovative approaches for successful wound management. Resveratrol (RSV) represents a promising therapeutic candidate, but its therapeutic efficacy and clinical applicability have been hampered by its rapid degradation and/or depletion. Herein, RSV was encapsulated into poly(ε-caprolactone) (PCL) microparticles by electrospraying with the aim to prolong and preserve RSV’s release/activity, without affecting its therapeutic properties. Electrospraying led to the fabrication of spherical (2 to 10 μm in size), negatively charged (<−1 mV), and quasi-monodisperse (PDI < 0.3) microparticles, with 60% RSV release after 28 days. Microencapsulation of RSV into PCL prevented its photochemical degradation and preserved its antioxidant properties over 72 h. The RSV-PCL microparticles did not exhibit any cytotoxicity on human dermal fibroblasts. RSV released from the microparticles was biologically functional and induced a significant increase in collagen type I deposition. Furthermore, the produced RSV-PCL microparticles reduced the expression of inflammatory (IL-6, IL-8, COX-2) and proteolytic (MMP-2, MMP-9) mediators. Collectively, our data clearly illustrate the potential of electrosprayed polymeric carriers for the sustained delivery of RSV to treat chronic wounds.

Insight into Cellular Uptake and Transcytosis of Peptide Nanoparticles in Spodoptera frugiperda Cells and Isolated Midgut

Silencing genes in insects by introducing double-stranded RNA (dsRNA) in the diet holds promise as a new pest management method. It has been demonstrated that nanoparticles (NPs) can potentiate dsRNA silencing effects by promoting cellular internalization and protecting dsRNA against early degradation. However, many mysteries of how NPs and dsRNA are internalized by gut epithelial cells and, subsequently, transported across the midgut epithelium remain to be unraveled. The sole purpose of the current study is to investigate the role of endocytosis and transcytosis in the transport of branched amphipathic peptide nanocapsules (BAPCs) associated with dsRNA through midgut epithelium cells. Spodoptera frugiperda midguts and the epithelial cell line Sf9, derived from S. frugiperda, were used to study transcytosis and endocytosis, respectively. Results suggest that clathrin-mediated endocytosis and macropinocytosis are largely responsible for cellular uptake, and once within the midgut, transcytosis is involved in shuttling BAPCs-dsRNA from the lumen to the hemolymph. In addition, BAPCs were not found to be toxic to Sf9 cells or generate damaging reactive species once internalized.

Drug-free neutrally charged polypeptide nanoparticles as anticancer agents

Cationic synthetic anticancer polymers and peptides have attracted increasing attention for advancing cancer treatment without causing drug resistance development. To circumvent in vivo instability and toxicity caused by cationic charges of the anticancer polymers/peptides, we report, for the first time, a nanoparticulate delivery system self-assembled from a negatively charged pH-sensitive polypeptide poly(ethylene glycol)-b-poly(ʟ-lysine)-graft-cyclohexene-1,2-dicarboxylic anhydride and a cationic anticancer polypeptide guanidinium-functionalized poly(ʟ-lysine) (PLL-Gua) via electrostatic interaction. The formation of nanoparticles (Gua-NPs) neutralized the positive charges of PLL-Gua. Both PLL-Gua and Gua-NPs killed cancer cells in a dose- and time-dependent manner, and induced cell death via apoptosis. Confocal microscopic studies demonstrated that PLL-Gua and Gua-NPs readily entered cancer cells, and Gua-NPs were taken up by the cells via endocytosis. Notably, Gua-NPs and PLL-Gua exhibited similar in vitro anticancer efficacy against MCF-7 and resistant MCF-7/ADR. PLL-Gua and Gua-NPs also induced similar morphological changes in MCF-7/ADR cells compared to MCF-7 cells, further indicating their ability to bypass drug resistance mechanisms in the MCF-7/ADR cells. More importantly, Gua-NPs with higher LD₅₀ and enhanced tumor accumulation significantly inhibited tumor growth with negligible side effects in vivo. Our findings shed light on the in vivo delivery of anticancer peptides and opened a new avenue for cancer treatment.

Theophylline-encapsulated Nile Tilapia fish scale-based collagen nanoparticles effectively target the lungs of male Sprague-Dawley rats

Nile Tilapia fish scale collagen has high biodegradability, excellent biocompatibility, and low antigenicity. We assessed both the encapsulation efficiency of theophylline into Nile Tilapia fish scale-based collagen nanoparticles and their stability as a pulmonary drug delivery system in male Sprague-Dawley rats. The present study has demonstrated the successful encapsulation of theophylline into the synthesised nanoparticles as shown by spectrophotometric analysis, light microscope, scanning electron microscope, transmission electron microscope, and dynamic light scattering. The antibacterial activity of the nanoparticles improves with increasing their concentrations. Intratracheal treatment of rats using theophylline-encapsulated nanoparticles reduced the levels of creatinine, alanine transaminase, and aspartate transaminase, compared to the control group. Nevertheless, nanoparticles combined with theophylline exhibited no effects on cholesterol and triglycerides levels. Histopathological examination revealed typical uniform and diffuse thickening of the alveolar walls with capillary oedema in treated rats. We concluded that the synthesised collagen nanoparticles appropriately target the lungs of male Sprague-Dawley rats when delivered via a nebuliser, showing good tolerability to lung cells. However, dose ratio of collagen nanoparticles to theophylline needs further evaluation. The nanoprecipitation method may be optimised to involve poorly water-soluble inhaled drugs, and avoid the drawbacks of traditional drug delivery.

Adaptive Synthesis of Functional Amphiphilic Dendrons as a Novel Approach to Artificial Supramolecular Objects

Supramolecular structures, such as micelles, liposomes, polymerosomes or dendrimerosomes, are widely studied and used as drug delivery systems. The behavior of amphiphilic building blocks strongly depends on their spatial distribution and shape of polar and nonpolar component. This report is focused on the development of new versatile synthetic protocols for amphiphilic carbosilane dendrons (amp-CS-DDNs) capable of self-assembly to regular micelles and other supramolecular objects. The presented strategy enables the fine modification of amphiphilic structure in several ways and also enables the facile connection of a desired functionality. DLS experiments demonstrated correlations between structural parameters of amp-CS-DDNs and the size of formed nanoparticles. For detailed information about the organization and spatial distribution of amp-CS-DDNs assemblies, computer simulation models were studied by using molecular dynamics in explicit water.

Therapeutic nanoparticles in the brain: A review of types, physicochemical properties and challenges

One of the main obstacles in the treatment of neurological diseases, perhaps the biggest one, is the delivery of therapeutic compounds to the central nervous system, and nanoparticles are promising tools to overcome this challenge. Different types of nanoparticles may be used as delivery systems, including liposomes, carbon nanotubes, and dendrimers. Nevertheless, these nanoparticles must display characteristics to be useful in brain drug delivery, such as stability, permeability to blood vessels, biocompatibility, and specificity. All of these aspects are intrinsically related to the physicochemical properties of nanoformulations: size, composition, electric charge, hydrophobicity, mucoadherence, permeability to the blood-brain barrier, and many others. Furthermore, there are challenging hindrances involved in the development and application of nanoparticles - hence the importance of studying and understanding these pharmaceutical tools.

Plant-derived nanotherapeutic systems to counter the overgrowing threat of resistant microbes and biofilms

Since antiquity, the survival of human civilization has always been threatened by the microbial infections. An alarming surge in the resistant microbial strains against the conventional drugs is quite evident in the preceding years. Furthermore, failure of currently available regimens of antibiotics has been highlighted by the emerging threat of biofilms in the community and hospital settings. Biofilms are complex dynamic composites rich in extracellular polysaccharides and DNA, supporting plethora of symbiotic microbial life forms, that can grow on both living and non-living surfaces. These enforced structures are impervious to the drugs and lead to spread of recurrent and non-treatable infections. There is a strong realization among the scientists and healthcare providers to work out alternative strategies to combat the issue of drug resistance and biofilms. Plants are a traditional but rich source of effective antimicrobials with wider spectrum due to presence of multiple constituents in perfect synergy. Other than the biocompatibility and the safety profile, these phytochemicals have been repeatedly proven to overcome the non-responsiveness of resistant microbes and films via multiple pathways such as blocking the efflux pumps, better penetration across the cell membranes or biofilms, and anti-adhesive properties. However, the unfavorable physicochemical attributes and stability issues of these phytochemicals have hampered their commercialization. These issues of the phytochemicals can be solved by designing suitably constructed nanoscaled structures. Nanosized systems can not only improve the physicochemical features of the encapsulated payloads but can also enhance their pharmacokinetic and therapeutic profile. This review encompasses why and how various types of phytochemicals and their nanosized preparations counter the microbial resistance and the biofouling. We believe that phytochemical in tandem with nanotechnological innovations can be employed to defeat the microbial resistance and biofilms. This review will help in better understanding of the challenges associated with developing such platforms and their future prospects.

Bay Leaf Extract-Based Near-Infrared Fluorescent Probe for Tissue and Cellular Imaging

The development of fluorescence dyes for near-infrared (NIR) fluorescence imaging has been a significant interest for deep tissue imaging. Among many imaging fluoroprobes, indocyanine green (ICG) and its analogues have been used in oncology and other medical applications. However, these imaging agents still experience poor imaging capabilities due to low tumor targetability, photostability, and sensitivity in the biological milieu. Thus, developing a biocompatible NIR imaging dye from natural resources holds the potential of facilitating cancer cell/tissue imaging. Chlorophyll (Chl) has been demonstrated to be a potential candidate for imaging purposes due to its natural NIR absorption qualities and its wide availability in plants and green vegetables. Therefore, it was our aim to assess the fluorescence characteristics of twelve dietary leaves as well as the fluorescence of their Chl extractions. Bay leaf extract, a high-fluorescence agent that showed the highest levels of fluorescence, was further evaluated for its tissue contrast and cellular imaging properties. Overall, this study confirms bay-leaf-associated dye as a NIR fluorescence imaging agent that may have important implications for cellular imaging and image-guided cancer surgery.

Safety and Toxicity Issues of Therapeutically Used Nanoparticles from the Oral Route

The emerging science of nanotechnology sparked a research attention in its potential benefits in comparison to the conventional materials used. Oral products prepared via nanoparticles (NPs) have garnered great interest worldwide. They are used commonly to incorporate nutrients and provide antimicrobial activity. Formulation into NPs can offer opportunities for targeted drug delivery, improve drug stability in the harsh environment of the gastrointestinal (GI) tract, increase drug solubility and bioavailability, and provide sustained release in the GI tract. However, some issues like the management of toxicity and safe handling of NPs are still debated and should be well concerned before their application in oral preparations. This article will help the reader to understand safety issues of NPs in oral drug delivery and provides some recommendations to the use of NPs in the drug industry.

Correlation between Biophysical Properties of Niosomes Elaborated with Chloroquine and Different Tensioactives and Their Transfection Efficiency

Lipid nanocarriers, such as niosomes, are considered attractive candidates for non-viral gene delivery due to their suitable biocompatibility and high versatility. In this work, we studied the influence of incorporating chloroquine in niosomes biophysical performance, as well as the effect of non-ionic surfactant composition and protocol of incorporation in their biophysical performance. An exhaustive comparative evaluation of three niosome formulations differing in these parameters was performed, which included the analysis of their thermal stability, rheological behavior, mean particle size, dispersity, zeta potential, morphology, membrane packing capacity, affinity to bind DNA, ability to release and protect the genetic material, buffering capacity and ability to escape from artificially synthesized lysosomes. Finally, in vitro biological studies were, also, performed in order to determine the compatibility of the formulations with biological systems, their transfection efficiency and transgene expression. Results revealed that the incorporation of chloroquine in niosome formulations improved their biophysical properties and the transfection efficiency, while the substitution of one of the non-ionic surfactants and the phase of addition resulted in less biophysical variations. Of note, the present work provides several biophysical parameters and characterization strategies that could be used as gold standard for gene therapy nanosystems evaluation.

Nanotechnology in cardiac stem cell therapy: cell modulation, imaging and gene delivery

The wide arena of applications opened by nanotechnology is multidimensional. It is already been proven that its prominence can continuously influence human life. The role of stem cells in curing degenerative diseases is another major area of research. Cardiovascular diseases are one of the major causes of death globally. Nanotechnology-assisted stem cell therapy could be used to tackle the challenges faced in the management of cardiovascular diseases. In spite of the positive indications and proven potential of stem cells to differentiate into cardiomyocytes for cardiac repair and regeneration during myocardial infarction, this therapeutic approach still remains in its infancy due to several factors such as non-specificity of injected cells, insignificant survival rate, and low cell retention. Attempts to improve stem cell therapy using nanoparticles have shown some interest among researchers. This review focuses on the major hurdles associated with cardiac stem cell therapy and the role of nanoparticles to overcome the major challenges in this field, including cell modulation, imaging, tracking and gene delivery.

This review summarizes the potential challenges present in cardiac stem cell therapy and the major role of nanotechnology to overcome these challenges including cell modulation, tracking and imaging of stem cells.

Assessment of Nanopollution from Commercial Products in Water Environments

The use of nano-enabled products (NEPs) can release engineered nanomaterials (ENMs) into water resources, and the increasing commercialisation of NEPs raises the environmental exposure potential. The current study investigated the release of ENMs and their characteristics from six commercial products (sunscreens, body creams, sanitiser, and socks) containing nTiO2, nAg, and nZnO. ENMs were released in aqueous media from all investigated NEPs and were associated with ions (Ag+ and Zn2+) and coating agents (Si and Al). NEPs generally released elongated (7-9 × 66-70 nm) and angular (21-80 × 25-79 nm) nTiO2, near-spherical (12-49 nm) and angular nAg (21-76 × 29-77 nm), and angular nZnO (32-36 × 32-40 nm). NEPs released varying ENMs' total concentrations (ca 0.4-95%) of total Ti, Ag, Ag+, Zn, and Zn2+ relative to the initial amount of ENMs added in NEPs, influenced by the nature of the product and recipient water quality. The findings confirmed the use of the examined NEPs as sources of nanopollution in water resources, and the physicochemical properties of the nanopollutants were determined. Exposure assessment data from real-life sources are highly valuable for enriching the robust environmental risk assessment of nanotechnology.

Microfluidic Technology for the Production of Hybrid Nanomedicines

Microfluidic technologies have recently been applied as innovative methods for the production of a variety of nanomedicines (NMeds), demonstrating their potential on a global scale. The capacity to precisely control variables, such as the flow rate ratio, temperature, total flow rate, etc., allows for greater tunability of the NMed systems that are more standardized and automated than the ones obtained by well-known benchtop protocols. However, it is a crucial aspect to be able to obtain NMeds with the same characteristics of the previously optimized ones. In this study, we focused on the transfer of a production protocol for hybrid NMeds (H-NMeds) consisting of PLGA, Cholesterol, and Pluronic® F68 from a benchtop nanoprecipitation method to a microfluidic device. For this aim, we modified parameters such as the flow rate ratio, the concentration of core materials in the organic phase, and the ratio between PLGA and Cholesterol in the feeding organic phase. Outputs analysed were the chemico-physical properties, such as size, PDI, and surface charge, the composition in terms of %Cholesterol and residual %Pluronic® F68, their stability to lyophilization, and the morphology via atomic force and electron microscopy. On the basis of the results, even if microfluidic technology is one of the unique procedures to obtain industrial production of NMeds, we demonstrated that the translation from a benchtop method to a microfluidic one is not a simple transfer of already established parameters, with several variables to be taken into account and to be optimized.

Potential of chitosan/alginate nanoparticles as a non-viral vector for gene delivery: Formulation and optimization using D-optimal design

Chitosan/alginate (Chi/Alg) nanoparticles as a non-viral vector for the Smad4 encoding plasmid were optimized utilizing D-optimal design based on the nanoparticles/plasmid ratio, Chi/Alg MW, and preparation method type. Following the optimization and validation of the best formula, morphology studies and FTIR measurements were performed to evaluate the optimized Chi/Alg/S NPs. Toxicity (MTT assay) and transfection studies were performed for the best formula in comparison with Lipofectamine 2000, and Polyethyleneimine (PEI) and evaluated using Green Fluorescence Protein (GFP) assay, Flow cytometry, and RT-PCR. The model predicted a particle size of 111 nm, loading efficacy (LE) of 43%, cumulative release (CMR) of 39%, the ζ-potential of +50 mV, and PDI of 0.13. The predicted point condition was as follows: NP ratio = 13, Chi/Alg MW ratio = 2.35, and preparation method type = 1. Microscopic findings revealed that the shape of nanoparticles was spherical. The Chi/Alg/S nanoparticles showed no toxicity and transfection efficacy of 29.9% was observed in comparison with Lipofectamine (35.5%) and PEI (30.9%).

Star polyester-based folate acid-targeting nanoparticles for doxorubicin and curcumin co-delivery to combat multidrug-resistant breast cancer

Chemotherapeutic treatments are indispensable in the treatment of breast cancer. However, the emergence of multidrug-resistance, strong cell toxicity, and poor targeting selection has inhibited their clinical application. In this study, two synergistic drugs, doxorubicin (DOX) and curcumin (CUR), were co-administered to overcome multidrug resistance (MDR). Based on the characteristics of the tumor microenvironment, we developed folic acid-modified nanoparticles ((DOX + CUR)-FA-NPs) based on a star-shaped polyester (FA-TRI-CL) to enhance the tumor targeting selectivity and drug loading (DL) capacity. The (DOX + CUR)-FA-NPs displayed a characteristic spheroid morphology with an ideal diameter (186.52 nm), polydispersity index (0.024), zeta potential (-18.87 mV), and good entrapment efficiency (97.64%/78.13%, DOX/CUR) and DL (20.27%/11.29%, DOX/CUR) values. In vitro pharmacokinetic and pharmacodynamic experiments demonstrated that the (DOX + CUR)-FA-NPs were gradually released, and they displayed the highest cell apoptosis and cellular uptake in MCF-7/ADR cells. Additionally, in vivo results illustrated that (DOX + CUR)-FA-NPs not only displayed significant tumor targeting and anticancer efficacy, but also induced less pathological damage to the normal tissue. In summary, co-administered DOX and CUR appeared to reverse MDR, and this targeted combinational nanoscale delivery system could thus be a promising carrier for tumor therapies in the future.

Novel Ellipsoid Chitosan-Phthalate Lecithin Nanoparticles for siRNA Delivery

Small interfering RNA (siRNA) has received increased interest as a gene therapeutic agent. However, instability and lack of safe, affordable, and effective carrier systems limit siRNA's widespread clinical use. To tackle this issue, synthetic vectors such as liposomes and polymeric nanoparticles have recently been extensively investigated. In this study, we exploited the advantages of reduced cytotoxicity and enhanced cellular penetration of chitosan-phthalate (CSP) together with the merits of lecithin (LC)-based nanoparticles (NPs) to create novel, ellipsoid, non-cytotoxic, tripolyphosphate (TPP)-crosslinked NPs capable of delivering siRNA efficiently. The resulting NPs were characterized by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and were found to be ellipsoid in the shape of ca. 180 nm in size, exhibiting novel double-layer shells, with excellent stability at physiological pH and in serum solutions. MTT assay and confocal fluorescence microscopy showed that CSP-LC-TPP NPs are non-cytotoxic and efficiently penetrate cancer cells in vitro. They achieved 44% silencing against SLUG protein in MDA-MB-453 cancer cells and were significantly superior to a commercial liposome-based transfection agent that achieved only 30% silencing under comparable conditions. Moreover, the NPs protected their siRNA cargos in 50% serum and from being displaced by variable concentrations of heparin. In fact, CSP-LC-TPP NPs achieved 26% transfection efficiency in serum containing cell culture media. Real-time wide-field fluorescence microscopy showed siRNA-loaded CSP-LC-TPP NPs to successfully release their cargo intracellularly. We found that the amphoteric nature of chitosan-phthalate polymer promotes the endosomal escape of siRNA and improves the silencing efficiency.

Environmentally friendly antibiofilm strategy based on cationized phytoglycogen nanoparticles

Biofilm tolerance to antibiotics has led to the search for new alternatives in treating biofilms. The use of metallic nanoparticles has been a suggested strategy against biofilms, but their potential environmental toxicity and high cost of synthesizing have limited their applications. In this study, we investigate the potential of polysaccharidic phytoglycogen nanoparticles extracted from corn, in treating cyanobacterial biofilms, which are the source of toxins and pollution in aquatic environments. Our results revealed that the surface of cyanobacterial cells was dominated by the negatively charged functional groups such as carboxylic and phosphoric groups. The native phytoglycogen (PhX) nanoparticles were dominated with non-charged groups, such as hydroxyl groups, and the cationized phytoglycogen (PhXC) nanoparticles showed positively charged surfaces due to the presence of quaternary ammonium cations. Our results indicated that, as opposed to PhX, PhXC strongly inhibited biofilm formation when dispersed in the culture medium. PhXC also eradicated the already grown cyanobacterial biofilms. The antibiofilm properties of PhXC were attributed to its strong electrostatic interactions with the cyanobacterial cells, which could inhibit cell/cell and cell/substrate interactions and nutrient exchange with the media. This class of antibacterial polysaccharide nanoparticles may provide a novel cost-effective and environment-friendly strategy for treating biofilm formation by a broad spectrum of bacteria.

Crucial Role of PLGA Nanoparticles in Mitigating the Amiodarone-Induced Pulmonary Toxicity

BACKGROUND

Amiodarone (AMD) is a widely used anti-arrhythmic drug, but its administration could be associated with varying degrees of pulmonary toxicity. In attempting to circumvent this issue, AMD-loaded polymeric nanoparticles (AMD-loaded NPs) had been designed.

MATERIALS AND METHODS

AMD was loaded in NPs by the nanoprecipitation method using two stabilizers: bovine serum albumin and Kolliphor® P 188. The physicochemical properties of the AMD-loaded NPs were determined. Among the prepared NPs, two ones were selected for further investigation of spectral and thermal analysis as well as morphological properties. Additionally, in vitro release patterns were studied and kinetically analyzed at different pH values. In vitro cytotoxicity of an optimized formula (NP4) was quantified using A549 and Hep-2 cell lines. In vivo assessment of the pulmonary toxicity on Sprague Dawley rats via histopathological and immunohistochemical evaluations was applied.

RESULTS

The developed NPs achieved a size not more than 190 nm with an encapsulation efficiency of more than 88%. Satisfactory values of loading capacity and yield were also attained. The spectral and thermal analysis demonstrated homogeneous entrapment of AMD inside the polymeric matrix of NPs. Morphology revealed uniform, core-shell structured, and sphere-shaped particles with a smooth surface. Furthermore, the AMD-loaded NPs exhibited a pH-dependent and diffusion-controlled release over a significant period without an initial burst effect. NP4 demonstrated a superior cytoprotective efficiency by diminishing cell death and significantly increasing the IC50 by more than threefold above the pure AMD. Also, NP4 ameliorated AMD-induced pulmonary damage in rats. Significant downregulation of inflammatory mediators and free radicle production were noticed in the NP4-treated rats.

CONCLUSION

The AMD-loaded NPs could ameliorate the pulmonary injury induced by the pure drug moieties. Cytoprotective, anti-fibrotic, anti-inflammatory, and antioxidant properties were presented by the optimized NPs (NP4). Future studies may be built on these findings for diminishing AMD-induced off-target toxicities.

Critical quality attributes in the development of therapeutic nanomedicines toward clinical translation

Nanomedicine is a rapidly emerging field with several breakthroughs in the therapeutic drug delivery application. The unique properties of the nanoscale delivery systems offer huge advantages to their payload such as solubilization, increased bioavailability, and improved pharmacokinetics with an overall goal of enhanced therapeutic index. Nanomedicine has the potential for integrating and enabling new therapeutic modalities. Several nanoparticle-based drug delivery systems have been granted approval for clinical use based on their outstanding clinical outcomes. Nanomedicine faces several challenges that hinder the realization of its full potential. In this review, we discuss the critical formulation- and biological-related quality features that significantly influence the performance of nanoparticulate systems in vivo. We also discuss the quality-by-design approach in the pharmaceutical manufacturing and its implementation in the nanomedicine. A deep understanding of these nanomedicine quality checkpoints and a systematic design that takes them into consideration will hopefully expedite the clinical translation process. Graphical abstract.

A size-shrinkable matrix metallopeptidase-2-sensitive delivery nanosystem improves the penetration of human programmed death-ligand 1 siRNA into lung-tumor spheroids

Given the maturation of small-interfering RNA (siRNA) techniques with nanotechnology, and because overexpression of human programmed death-ligand 1 (PD-L1) is crucial for T cell inactivation and immunosuppression of the tumor microenvironment, application of siRNA-PD-L1 has demonstrated positive progress in preclinical studies; however, the limited penetration of this compound into solid tumors remains a challenge. To decrease PD-L1 expression and increase the penetration efficacy of solid tumors, we synthesized a novel tumor-microenvironment-sensitive delivery polymer by conjugating hyaluronic acid (HA) to polyethyleneimine (PEI), with a matrix metalloproteinase-2 (MMP-2)-sensitive peptide acting as the linker (HA-P-PEI), for use in delivery of PD-L1-siRNA. Concurrent synthesis of a linker-less HA-PEI compound allowed confirmation that negatively charged siRNA can be complexed onto the positively charged HA-PEI and HA-P-PEI compounds to form nanoparticles with the same particle size and uniform distribution with serum stability. We found that the size of the HA-P-PEI/siRNA nanoparticles decreased to <10 nm upon addition of MMP-2, and that H1975 cells overexpressing CD44, PD-L1, and MMP-2 aided confirmation of the delivery efficacy of the HA-P-PEI/siRNA nanocomplexes. Additionally, the use of HA-P-PEI caused less cytotoxicity than PEI alone, demonstrating its high cellular uptake. Moreover, pretreatment with MMP-2 increased nanocomplex tumor permeability, and western blot showed that HA-P-PEI/PD-L1-siRNA efficiently downregulated the PD-L1 expression in H1975 cells. These results demonstrated a novel approach for siRNA delivery and tumor penetration for future clinical applications in cancer treatment.

Interdependency of influential parameters in therapeutic nanomedicine

Introduction:Current challenges to successful clinical translation of therapeutic nanomedicine have discouraged many stakeholders, including patients. Significant effort has been devoted to uncovering the reasons behind the less-than-expected success, beyond failures or ineffectiveness, of therapeutic nanomedicine products (e.g. cancer nanomedicine). Until we understand and address the factors that limit the safety and efficacy of NPs, both individually and in combination, successful clinical development will lag.Areas covered:This review highlights the critical roles of interdependent factors affecting the safety and therapeutic efficacy of therapeutic NPs for drug delivery applications.Expert opinion:Deep analysis of the current nanomedical literature reveals ahistory of unanticipated complexity by awide range of stakeholders including researchers. In the manufacture of nanomedicines themselves, there have been persistent difficulties with reproducibility and batch-to-batch variation. The unanticipated complexity and interdependency of nano-bio parameters has delayed our recognition of important factors affecting the safety and therapeutic efficacy of nanomedicine products. These missteps have had many factors including our lack of understanding of the interdependency of various factors affecting the biological identity and fate of NPs and biased interpretation of data. All these issues could raise significant concern regarding the reproducibility- or even the validity- of past publications that in turn formed the basis of many clinical trials of therapeutic nanomedicines. Therefore, the individual and combined effects of previously overlooked factors on the safety and therapeutic efficacy of NPs need to be fully considered in nanomedicine reports and product development.

A Concept Evaluation Study of a New Combination Bictegravir plus Tenofovir Alafenamide Nanoformulation with Prolonged Sustained-Drug-Release Potency for HIV-1 Preexposure Prophylaxis

The antiretroviral treatment (ART) approach is the best-prescribed approach to date for preexposure prophylaxis (PrEP) for high-risk individuals. However, the daily combination antiretroviral (cARV) regimen has become cumbersome for healthy individuals, leading to nonadherence. Recent surveys showed high acceptance of parenteral sustained-release ART enhancing PrEP adherence. Our approach is to design a parenteral nanoparticle (NP)-based cARV sustained-release (cARV-SR) system as long-acting HIV PrEP. Here, we report a new combination of two potent ARVs (tenofovir alafenamide fumarate [TAF] and bictegravir [BIC]) loaded as a nanoformulation intended as a cARV-SR for PrEP. The BIC+TAF NPs were fabricated by using a standardized in-house methodology. In vitro intracellular kinetics, cytotoxicity, and HIV-1 protection studies demonstrated that BIC+TAF encapsulation prolonged drug retention, reduced drug-associated cytotoxicity, and enhanced HIV protection. In human peripheral blood mononuclear cells, nanoformulated BIC+TAF demonstrated significant (P < 0.05) improvement in the drug's selectivity index by 472 times compared to the BIC+TAF in solution. In vivo pharmacokinetic study of BIC, TAF, and respective drug metabolites in female BALB/c mice after single subcutaneous doses of BIC+TAF NPs demonstrated plasma drug concentrations of BIC and tenofovir above the intracellular 50% inhibitory concentration during the entire 30-day study period and prolonged persistence of both active drugs in the HIV target organs, including the vagina, colon, spleen, and lymph nodes. This report demonstrates that the encapsulation of BIC+TAF in a nanoformulation improved its therapeutic selectivity and the in vivo pharmacokinetics of free drugs. Based on these preliminary studies, we hypothesize that cARV-SR has potential as an innovative once-monthly delivery treatment for PrEP.

pH-Sensitive Acetalated Dextran/PLGA-Based Double-Layered Microparticles and Their Application in Food Preservation

Double-layered microparticles (150-190 μm) composed of biodegradable poly(lactic-co-glycolic acid) (PLGA) and pH-responsive acetalated dextran were fabricated using a one-step emulsion solvent evaporation technique. Nearly 80% dextran was released from the microparticles after 20 days of incubation in pH ∼ 5 medium, and the complete disappearance of shell (Ac-dextran) layer was also evident from scanning electron microscopy (SEM) images after 20 days under the same condition. However, the Ac-dextran shell was found to remain unchanged in neutral pH. Dual actives such as antibacterial (benzoic acid) and antioxidant (tocopherol) were incorporated in the shell and core of the microparticles to exploit their applications as food-preserving materials. An accelerated release of antibacterial and a controlled release of antioxidant were found to be useful for prolonging the shelf life of a low-pH food such as pork broth (pH ∼ 5) over 20 days by providing complete bacterial growth inhibition and high radical scavenging efficiency (70-90%).

Redox-Responsive Hyaluronic Acid-Based Nanogels for the Topical Delivery of the Visual Chromophore to Retinal Photoreceptors

Delivering therapeutics to the posterior segment of the eye is challenging due to various anatomical and physical barriers. While significant improvements have been realized by introducing direct injections to diseased sites, these approaches come with potential side effects that can range from simple inflammation to severe retinal damage. The topical instillation of drugs remains a safer and preferred alternative for patients' compliance. Here, we report the synthesis of penetratin-complexed, redox-responsive hyaluronic acid-based nanogels for the triggered release and delivery of therapeutics to the posterior part of the eye via topical application. The synthesized nanogels were shown to release their load only when exposed to a reducing environment, similar to the cytoplasm. As a model drug, visual chromophore analog, 9-cis-retinal, was loaded into nanogels and efficiently delivered to the mouse retina's photoreceptors when applied topically. Electroretinogram measurements showed a partial recovery of photoreceptor function in all treated eyes versus untreated controls. To the best of our knowledge, this report constitutes the first attempt to use a topically applied triggered-release drug delivery system to target the pigmented layer of the retina, in addition to the first attempt to deliver the visual chromophore topically.

Silicone Oil-Based Nanoadjuvants as Candidates for a New Formulation of Intranasal Vaccines

Many conventional vaccines are administered via a needle injection, while most pathogens primarily invade the host via mucosal surfaces. Moreover, protective IgA antibodies are insufficiently induced by parenteral vaccines. Mucosal immunity induces both local and systemic response to pathogens and typically lasts for long periods of time. Therefore, vaccination via mucosal routes has been increasingly explored. However, mucosal vaccines require potent adjuvants to become efficacious. Despite many efforts to develop safe and robust adjuvants for mucosal vaccines, only a few have been approved for use in human formulations. The aim of our study was to design, develop and characterize new silicone oil-based nanoadjuvant candidates for intranasal vaccines with potential to become mucosal adjuvants. We have developed an array of nanoadjuvant candidates (NACs), based on well-defined ingredients. NAC1, 2 and 3 are based on silicone oil, but differ in the used detergents and organic solvents, which results in variations in their droplet size and zeta potential. NACs' cytotoxicity, Tumor Necrosis Factor α (TNF-α) induction and their effect on antigen engulfment by immune cells were tested in vitro. Adjuvant properties of NACs were verified by intranasal vaccination of mice together with ovalbumin (OVA). NACs show remarkable stability and do not require any special storage conditions. They exhibit bio-adhesiveness and influence the degree of model protein engulfment by epithelial cells. Moreover, they induce high specific anti-OVA IgG antibody titers after two intranasal administrations. Nanoadjuvant candidates composed of silicone oil and cationic detergents are stable, exhibit remarkable adjuvant properties and can be used as adjuvants for intranasal immunization.

Antibacterial Activity of Positively and Negatively Charged Hematite (α-Fe2O3) Nanoparticles to Escherichia coli, Staphylococcus aureus and Vibrio fischeri

In the current study, the antibacterial activity of positively and negatively charged spherical hematite (α-Fe2O3) nanoparticles (NPs) with primary size of 45 and 70 nm was evaluated against clinically relevant bacteria Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) as well as against naturally bioluminescent bacteria Vibrio fischeri (an ecotoxicological model organism). α-Fe2O3 NPs were synthesized using a simple green hydrothermal method and the surface charge was altered via citrate coating. To minimize the interference of testing environment with NP's physic-chemical properties, E. coli and S. aureus were exposed to NPs in deionized water for 30 min and 24 h, covering concentrations from 1 to 1000 mg/L. The growth inhibition was evaluated following the postexposure colony-forming ability of bacteria on toxicant-free agar plates. The positively charged α-Fe2O3 at concentrations from 100 mg/L upwards showed inhibitory activity towards E. coli already after 30 min of contact. Extending the exposure to 24 h caused total inhibition of growth at 100 mg/L. Bactericidal activity of positively charged hematite NPs against S. aureus was not observed up to 1000 mg/L. Differently from positively charged hematite NPs, negatively charged citrate-coated α-Fe2O3 NPs did not exhibit any antibacterial activity against E. coli and S. aureus even at 1000 mg/L. Confocal laser scanning microscopy and flow cytometer analysis showed that bacteria were more tightly associated with positively charged α-Fe2O3 NPs than with negatively charged citrate-coated α-Fe2O3 NPs. Moreover, the observed associations were more evident in the case of E. coli than S. aureus, being coherent with the toxicity results. Vibrio fischeri bioluminescence inhibition assays (exposure medium 2% NaCl) and colony forming ability on agar plates showed no (eco)toxicity of α-Fe2O3 (EC50 and MBC > 1000 mg/L).

Human small intestine cancer cell membrane-camouflaged quercetin-melanin for antibacterial and antitumor activity

E. coli has become an important factor that can lead to cancer because of its ability to cause diverse intestinal changes. Nano-polymer materials provide ideal drug delivery systems for preparing antibacterial and anti-cancer drugs because of their unique structure, easy modification, and high drug loading. The modified natural melanin has the potential to be an excellent nano-carrier. By improving the water-solubility and biocompatibility of the loaded natural drug quercetin, the antibacterial effect of quercetin can be fully played. Here, natural melanin was extracted from frozen squid to synthesize carrier polydopamine (PDA) nanoparticles, and the natural drug quercetin (Q) was modified on the surface of PDA by π-π bond and covalent bond action to produce melanin-quercetin (PDA-Q). We also developed human small intestinal cancer cells (HIC) membrane-camouflaged melanin-Quercetin (PDA-Q) nanoparticles as an anti-cancer platform in vivo. The potential bacteriostatic mechanism was likely driven by the penetration of PDA-Q in E. coli cells, damaging the integrity of the membranes of E. coli and inducing cell death. The mice wound experiment and bacteremia model experiment revealed that C@PDA-Q had a strong inhibitory effect on E. coli in vivo. In addition, the results of the in vitro tumor test also revealed that C@PDA-Q had strong anti-tumor activity against HIC cells of human small intestinal cancer, and the IC50 value was 12.3 ± 0.7 μg/ml, which was slightly better than that for cisplatin. As both melanin nanoparticles and HIC membrane are natural biomaterials, the synthesized C@PDA-Q nano-polymer material shows great potential for use in anti-cancer nano-drug loading.

Biodegradable Polymeric Nanoparticles for Drug Delivery to Solid Tumors

Advances in nanotechnology have favored the development of novel colloidal formulations able to modulate the pharmacological and biopharmaceutical properties of drugs. The peculiar physico-chemical and technological properties of nanomaterial-based therapeutics have allowed for several successful applications in the treatment of cancer. The size, shape, charge and patterning of nanoscale therapeutic molecules are parameters that need to be investigated and modulated in order to promote and optimize cell and tissue interaction. In this review, the use of polymeric nanoparticles as drug delivery systems of anticancer compounds, their physico-chemical properties and their ability to be efficiently localized in specific tumor tissues have been described. The nanoencapsulation of antitumor active compounds in polymeric systems is a promising approach to improve the efficacy of various tumor treatments.

Complexation design of cationized gelatin and molecular beacon to visualize intracellular mRNA

The objective of this study is to prepare cationized gelatin-molecular beacon (MB) complexes for the visualization of intracellular messenger RNA (mRNA). The complexes were prepared from cationized gelatins with different extents of cationization and different mixing ratios of MB to cationized gelatin. The apparent size of complexes was almost similar, while the zeta potential was different among the complexes. Irrespective of the preparation conditions, the complexes had a sequence specificity against the target oligonucleotides in hybridization. The cytotoxicity and the amount of complexes internalized into cells increased with an increase in the cationization extent and the concentration of cationized gelatin. After the incubation with complexes prepared from cationized gelatin with the highest extent of cationization and at mixing ratios of 10 and 20 pmole MB/μg cationized gelatin, a high fluorescent intensity was detected. On the other hand, the complex prepared with the mixing ratio at 20 pmole/μg did not show any cytotoxicity. The complex was the most effective to visualize the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA endogenously present. In addition, even for enhanced green fluorescent protein (EGFP) mRNA exogenously transfected, the complex permitted to effectively detect it as well. It is concluded that both the endogenous and exogenous mRNA can be visualized in living cells by use of cationized gelatin-MB complexes designed.

Polyamidoamine Dendrimers Decorated Multifunctional Polydopamine Nanoparticles for Targeted Chemo- and Photothermal Therapy of Liver Cancer Model

The development of multifunctional drug delivery systems combining two or more nanoparticle-mediated therapies for efficient cancer treatment is highly desired. To face this challenge, a photothermally active polydopamine (PDA) nanoparticle-based platform was designed for the loading of chemotherapeutic drug and targeting of cancer cells. PDA spheres were first functionalized with polyamidoamine (PAMAM) dendrimers followed by the conjugation with polyethylene glycol (PEG) moieties and folic acid (FA) targeting ligand. The anticancer drug doxorubicin (DOX) was then absorbed on the particle surface. We performed the physico-chemical characterization of this versatile material and we assessed further its possible application in chemo- and photothermal therapy using liver cancer cell model. These nanoparticles exhibited high near-infrared photothermal conversion efficacy and allowed for loading of the drug, which upon release in specifically targeted cancer cells suppressed their growth. Using cell proliferation, membrane damage, apoptosis, and oxidative stress assays we demonstrated high performance of this nanosystem in cancer cell death induction, providing a novel promising approach for cancer therapy.

Poly-ε-caprolactone Nanoparticles Loaded with 4-Nerolidylcatechol (4-NC) for Growth Inhibition of Microsporum canis

Dermatophyte fungal infections are difficult to treat because they need long-term treatments. 4-Nerolidylcatechol (4-NC) is a compound found in Piper umbellatum that has been reported to demonstrate significant antifungal activity, but is easily oxidizable. Due to this characteristic, the incorporation in nanostructured systems represents a strategy to guarantee the compound’s stability compared to the isolated form and the possibility of improving antifungal activity. The objective of this study was to incorporate 4-NC into polymeric nanoparticles to evaluate, in vitro and in vivo, the growth inhibition of Microsporum canis. 4-NC was isolated from fresh leaves of P. umbellatum, and polymer nanoparticles of polycaprolactone were developed by nanoprecipitation using a 1:5 weight ratio (drug:polymer). Nanoparticles exhibited excellent encapsulation efficiency, and the antifungal activity was observed in nanoparticles with 4-NC incorporated. Polymeric nanoparticles can be a strategy employed for decreased cytotoxicity, increasing the stability and solubility of substances, as well as improving the efficacy of 4-NC.

Magnetite Nanoparticles and Spheres for Chemo- and Photothermal Therapy of Hepatocellular Carcinoma in vitro

Introduction

We present a multimodal nanoplatforms for the treatment of hepatocellular carcinoma (HCC) in vitro. The nanoplatforms are based on polydopamine (PDA)-coated magnetite nanoparticles (NPs) and spheres (sMAG) with PAMAM dendrimers and functionalized with NHS-PEG-Mal (N-hydroxysuccinimide–polyethylene glycol–maleimide) linker, which allows their functionalization with a folic acid derivative. The nanomaterials bearing a folic acid-targeting moiety show high efficiency in killing cancer cells in the dual chemo- and photothermal therapy (CT-PTT) of the liver cancer cells in comparison to modalities performed separately.

Materials and Methods

All materials are characterized in detail with transmission electron microscopy, Fourier transform infrared spectroscopy, thermogravimetric analysis, zeta potential and magnetic measurements. Also, photothermal properties were determined under irradiation of nanoparticles with laser beam of 2 W/cm². The nontoxicity of nanoparticles with doxorubicin and without was checked by WST and LIVE/DEAD assay. Those tests were also used to evaluate materials bearing folic acid and anticancer drug in combined chemo- and photothermal therapy of HCC. Further, the generation of reactive oxygen species profile was also evaluated using flow cytometry test.

Results

Both NPs and sMAG showed high photothermal properties. Nevertheless, the higher photothermal response was found for magnetic spheres. Materials of concentration above 10 µg/mL reveal that their activity was comparable to free doxorubicin. It is worth highlighting that a functionalized magnetic sphere with DOXO more strongly affected the HepG2 cells than smaller functionalized nanoparticles with DOXO in the performed chemotherapy. This can be attributed to the larger size of particles and a different method of drug distribution. In the further stage, both materials were assessed in combined chemo- and photothermal therapy (CT-PTT) which revealed that magnetic spheres were also more effective in this modality than smaller nanoparticles.

Conclusion

Here, we present two types of nanomaterials (nanoparticles and spheres) based on polydopamine and PAMAM dendrimers g.5.0 functionalized with NHS-PEG-Mal linker terminated with folic acid for in vitro hepatocellular carcinoma treatment. The obtained materials can serve as efficient agents for dual chemo- and photothermal therapy of HCC. We also proved that PDA-coated magnetic spheres were more efficient in therapies based on near-infrared irradiation because determined cell viabilities for those materials are lower than for the same concentrations of nanomaterials based on small magnetic nanoparticles.

Biodegradable and biocompatible spherical dendrimer nanoparticles with a gallic acid shell and a double-acting strong antioxidant activity as potential device to fight diseases from "oxidative stress"

Gallic acid (GA) is a natural polyphenol with remarkable antioxidant power present in several vegetables and fruits. A normal feeding regime leads to a daily intake of GA which is reasonably regarded as "natural" and "safe" for humans. It owns strong potentials as alternative to traditional drugs to treat several diseases triggered by oxidative stress (OS), but poor gastrointestinal absorbability, pharmacokinetic drawbacks, and fast metabolism limit its clinical application. In this work, a fifth-generation polyester-based dendrimer was firstly prepared as a better absorbable carrier to protect and deliver GA. Then, by its peripheral esterification with GA units, a GA-enriched delivering system (GAD) with remarkable antioxidant power and high potential against diseases from OS was achieved. Scanning electron microscopy results and dynamic light scattering analysis revealed particles with an average size around 387 and 375 nm, respectively, and an extraordinarily spherical morphology. These properties, by determining a large particles surface area, typically favour higher systemic residence time and bio-efficiency. Z-potential of - 25 mV suggests satisfactory stability in solution with tendency to form megamers and low polydispersity index. GAD showed intrinsic antioxidant power, higher than GA by 4 times and like prodrugs, and it can carry contemporary several bioactive GA units versus cells. In physiological condition, the action of pig liver esterase (PLE), selected as a model of cells esterase, hydrolyses GAD to non-cytotoxic small molecules, thus setting free the bioactive GA units, for further antioxidant effects. Cytotoxicity studies performed on two cell lines demonstrated a high cell viability. Graphical Abstract Graphical Abstract.

The Potential of Milk-Derived Exosomes for Drug Delivery

BACKGROUND

Exosomes, one of the extracellular vesicles, are widely present in all biological fluids and play an important role in intercellular communication. Due to their hydrophobic lipid bilayer and aqueous hydrophilic core structure, they are considered a possible alternative to liposome drug delivery systems. Not only do they protect the cargo like liposomes during delivery, but they are also less toxic and better tolerated. However, due to the lack of sources and methods for obtaining enough exosomes, the therapeutic application of exosomes as drug carriers is limited.

METHODS

A literature search was performed using the ScienceDirect and PubMed electronic databases to obtain information from published literature on milk exosomes related to drug delivery.

RESULTS

Here, we briefly reviewed the current knowledge of exosomes, expounded the advantages of milk-derived exosomes over other delivery vectors, including higher yield, the oral delivery characteristic and additional therapeutic benefits. The purification and drug loading methods of milk exosomes, and the current application of milk exosomes were also introduced.

CONCLUSION

The emergence of milk-derived exosomes is expected to break through the limitations of exosomes as therapeutic carriers of drugs. We hope to raise awareness of the therapeutic potential of milk-derived exosomes as a new drug delivery system.