Effects of nanoparticle size and gestational age on maternal biodistribution and toxicity of gold nanoparticles in pregnant mice

Advance in placenta drug delivery: concern for placenta-originated disease therapy

In the therapy of placenta-originated diseases during pregnancy, the main challenges are fetal exposure to drugs, which can pass through the placenta and cause safety concerns for fetal development. The design of placenta-resident drug delivery system is an advantageous method to minimize fetal exposure as well as reduce adverse maternal off-target effects. By utilizing the placenta as a biological barrier, the placenta-resident nanodrugs could be trapped in the local placenta to concentrate on the treatment of this abnormal originated tissue. Therefore, the success of such systems largely depends on the placental retention capacity. This paper expounds on the transport mechanism of nanodrugs in the placenta, analyzes the factors that affect the placental retention of nanodrugs, and summarizes the advantages and concerns of current nanoplatforms in the treatment of placenta-originated diseases. In general, this review aims to provide a theoretical basis for the construction of placenta-resident drug delivery systems, which will potentially enable safe and efficient clinical treatment for placenta-originated diseases in the future.

Delivery and short-term maternal and fetal safety of vaginally administered PEG-PLGA nanoparticles

At the onset of pregnancy, people with preexisting conditions face additional challenges in carrying their pregnancy to term, as the safety of the developing fetus and pregnant person is a significant factor of concern. Nanoparticle (NP)-based therapies have displayed success against various conditions and diseases in non-pregnant patients, but the use of NPs in maternal-fetal health applications needs to be better established. Local vaginal delivery of NPs is a promising administration route with the potential to yield high cargo retention in the vagina and improved therapeutic efficacy compared to systemic administration that results in rapid NP clearance by the hepatic first-pass effect. In this study, we investigated the biodistribution and short-term toxicity of poly(ethylene glycol)-poly(lactic-co-glycolic acid) (PEG-PLGA) NPs in pregnant mice following vaginal delivery. The NPs were either loaded with DiD fluorophores for tracking cargo distribution (termed DiD-PEG-PLGA NPs) or included Cy5-tagged PLGA in the formulation for tracking polymer distribution (termed Cy5-PEG-PLGA NPs). DiD-PEG-PLGA NPs were administered at gestational day (E)14.5 or 17.5, and cargo biodistribution was analyzed 24 h later by fluorescence imaging of whole excised tissues and histological sections. No gestational differences in DiD distribution were observed, so Cy5-PEG-PLGA NPs were administered at only E17.5 to evaluate polymer distribution in the reproductive organs of pregnant mice. Cy5-PEG-PLGA NPs distributed to the vagina, placentas, and embryos, whereas DiD cargo was only observed in the vagina. NPs did not impact maternal, fetal, or placental weight, suggesting they display no short-term effects on maternal or fetal growth. The results from this study encourage future investigation into the use of vaginally delivered NP therapies for conditions affecting the vagina during pregnancy.

Dual-targeted delivery system using hollow silica nanoparticles with H+-triggered bubble generating characteristic coated with hyaluronic acid and AS1411 for cancer therapy

OBJECTIVE

Herein, a dual-targeting delivery system using mesoporous silica nanoparticles with hollow structures (HMSNs) was developed for the specific delivery of epirubicin (EPI) to cancer cells and introducing a H+-triggered bubble generating nanosystem (BGNS). HMSNs containing EPI are covered by hyaluronic acid (HA) shell and AS1411 aptamer to create the BGNS-EPI-HA-Apt complex, which is highly selective against CD44 marker and nucleolin overexpressed on the surface of tumor cells.

METHODS

MTT assay compared the cytotoxicity of different treatments in CHO (Chinese hamster ovary) cells as well as 4T1 (murine mammary carcinoma) and MCF-7 (human breast adenocarcinoma) cells. The internalization of Epi was assessed by flow cytometry along with fluorescence imaging. In vivo studies were conducted on BALB/c mice bearing a tumor from 4T1 cell line where monitoring included measuring tumor volume, mouse weight changes over time alongside mortality rate; accumulation levels for Epi within organs were also measured during this process.

RESULTS

The collected data illustrated that BGNS-EPI-HA-Apt complex controlled the release of EPI in a sustained method. Afterward, receptor-mediated internalization via nucleolin and CD44 was verified in 4T1 and MCF-7 cells using fluorescence microscopy assay and flow cytometry analysis. The results of tumor inhibitory effect study exhibited that BGNS-EPI-HA-Apt complex decreased off-target effect and improved on-target effects because of its targeting ability.

CONCLUSION

The data acquired substantiates that HA-surface modified HMSNs functionalized with aptamers possess significant potential as a focused platform for efficient transportation of anticancer agents to neoplastic tissues.

UV-Accelerated Synthesis of Gold Nanoparticle-Pluronic Nanocomposites for X-ray Computed Tomography Contrast Enhancement

Eco-friendly chemical methods using FDA-approved Pluronic F127 (PLU) block copolymer have garnered much attention for simultaneously forming and stabilizing Au nanoparticles (AuNPs). Given the remarkable properties of AuNPs for usage in various fields, especially in biomedicine, we performed a systematic study to synthesize AuNP-PLU nanocomposites under optimized conditions using UV irradiation for accelerating the reaction. The use of UV irradiation at 254 nm resulted in several advantages over the control method conducted under ambient light (control). The AuNP-PLU-UV nanocomposite was produced six times faster, lasting 10 min, and exhibited lower size dispersion than the control. A set of experimental techniques was applied to determine the structure and morphology of the produced nanocomposites as affected by the UV irradiation. The MTT assay was conducted to estimate IC50 values of AuNP-PLU-UV in NIH 3T3 mouse embryonic fibroblasts, and the results suggest that the sample is more compatible with cells than control samples. Afterward, in vivo maternal and fetal toxicity assays were performed in rats to evaluate the effect of AuNP-PLU-UV formulation during pregnancy. Under the tested conditions, the treatment was found to be safe for the mother and fetus. As a proof of concept or application, the synthesized Au:PLU were tested as contrast agents with an X-ray computed tomography scan (X-ray CT).

Oxidative Stress and Mitochondrial Dysfunction in Chronic Kidney Disease

The kidney contains many mitochondria that generate ATP to provide energy for cellular processes. Oxidative stress injury can be caused by impaired mitochondria with excessive levels of reactive oxygen species. Accumulating evidence has indicated a relationship between oxidative stress and kidney diseases, and revealed new insights into mitochondria-targeted therapeutics for renal injury. Improving mitochondrial homeostasis, increasing mitochondrial biogenesis, and balancing mitochondrial turnover has the potential to protect renal function against oxidative stress. Although there are some reviews that addressed this issue, the articles summarizing the relationship between mitochondria-targeted effects and the risk factors of renal failure are still few. In this review, we integrate recent studies on oxidative stress and mitochondrial function in kidney diseases, especially chronic kidney disease. We organized the causes and risk factors of oxidative stress in the kidneys based in their mitochondria-targeted effects. This review also listed the possible candidates for clinical therapeutics of kidney diseases by modulating mitochondrial function.

The Use of Medicinal Plant-Derived Metallic Nanoparticles in Theranostics

In the quest to effectively diagnose and treat the diseases that afflict mankind, the development of a tool capable of simultaneous detection and treatment would provide a significant cornerstone for the survival and control of these diseases. Theranostics denotes a portmanteau of therapeutics and diagnostics which simultaneously detect and treat ailments. Research advances have initiated the advent of theranostics in modern medicine. Overall, theranostics are drug delivery systems with molecular or targeted imaging agents integrated into their structure. The application of theranostics is rising exponentially due to the urgent need for treatments that can be utilized for diagnostic imaging as an aid in precision and personalised medicine. Subsequently, the emergence of nanobiotechnology and the green synthesis of metallic nanoparticles (MNPs) has provided one such avenue for nanoscale development and research. Of interest is the drastic rise in the use of medicinal plants in the synthesis of MNPs which have been reported to be potentially effective in the diagnosis and treatment of diseases. At present, medicinal plant-derived MNPs have been cited to have broad pharmacological applications and have been studied for their potential use in the treatment and management of cancer, malaria, microbial and cardiovascular diseases. The subject of this article regards the role of medicinal plants in the synthesis of MNPs and the potential role of MNPs in the field of theranostics.

Maternal exposure to CeO2NPs derails placental development through trophoblast dysfunction mediated by excessive autophagy activation

BACKGROUND

The increasing use of cerium dioxide nanoparticles (CeO₂NPs) in biomedical field has attracted substantial attention about their potential risks to human health. Recent studies have shown that nanoparticles can induce placental dysfunction and even fetal abortion, but a more detailed mechanism of nanoparticles affecting placental development remains elusive.

RESULTS

Here, we constructed a mouse exposure model with different doses of CeO₂NPs (2.5, 4, 5, 7.5, and 10 mg kg^-1 day^-1, average particle size 3-5 nm), finding that intravenous exposure to pregnant mice with CeO₂NPs could cause abnormal placental development. Deposited nanoparticles were able to be observed in the placental trophoblast at doses of 5 and 7.5 mg kg^-1 day^-1. Diving into molecular mechanisms indicated that CeO₂NPs exposure could lead to autophagy activation in placental trophoblast. At the cellular level, exposure to CeO₂NPs inhibited the migration and invasion of HTR-8/SVneo and activated the autophagy through mammalian target of rapamycin complex1 (mTORC1) signaling pathway. Furthermore, inhibition of autophagy initiation by 3-Methyladenine (3-MA) partially restored the function of HTR-8/SVneo, while blocking autophagic flow by Chloroquine (CQ) aggravated the functional damage.

CONCLUSIONS

Maternal exposure to CeO₂NPs impairs placental development through trophoblast dysfunction mediated by excessive autophagy activation. These results suggested that autophagy dysfunction may be a potential mechanism for the impairment of trophoblast by CeO₂NPs exposure. As above, our findings provide insights into the toxicity mechanism to the reproductive system induced by rare-earth nanoparticles exposure.

Particle Engineering of Innovative Nanoemulsion Designs to Modify the Accumulation in Female Sex Organs by Particle Size and Surface Charge

Particle engineering of nanosized drug delivery systems (DDS) can be used as a strategic tool to influence their pharmacokinetics after intravenous (i.v.) application by the targeted adaptation of their particle properties according to the needs at their site of action. This study aimed to investigate particle properties depending on patterns in the biodistribution profile to modify the accumulation in the female sex organs using tailor-made nanoemulsion designs and thereby to either increase therapeutic efficiency for ovarian dysfunctions and diseases or to decrease the side effects caused by unintended accumulation. Through the incorporation of the anionic phospholipid phosphatidylglycerol (PG) into the stabilizing macrogol 15 hydroxystearate (MHS) layer of the nanoemulsions droplets, it was possible to produce tailor-made nanoparticles with tunable particle size between 25 to 150 nm in diameter as well as tunable surface charges between −2 to nearly −30 mV zeta potential using a phase inversion-based process. Three chosen negatively surface-charged nanoemulsions of 50, 100, and 150 nm in diameter showed very low cellular toxicities on 3T3 and NHDF fibroblasts and merely interacted with the blood cells, but instead stayed inert in the plasma. In vivo and ex vivo fluorescence imaging of adult female mice i.v. injected with the negatively surface-charged nanoemulsions revealed a high accumulation depending on their particle size in the reticuloendothelial system (RES), being found in the liver and spleen with a mean portion of the average radiant efficiency (PARE) between 42–52%, or 8–10%, respectively. With increasing particle size, an accumulation in the heart was detected with a mean PARE up to 8%. These three negatively surface-charged nanoemulsions overcame the particle size-dependent accumulation in the female sex organs and accumulated equally with a small mean PARE of 5%, suitable to reduce the side effects caused by unintended accumulation while maintaining different biodistribution profiles. In contrast, previously investigated neutral surface-charged nanoemulsions accumulated with a mean PARE up to 10%, strongly dependent on their particle sizes, which is useful to improve the therapeutic efficacy for ovarian dysfunctions and diseases.

Ovarian Accumulation of Nanoemulsions: Impact of Mice Age and Particle Size

Nanotechnology in the field of drug delivery comes with great benefits due to the unique physicochemical properties of newly developed nanocarriers. However, they may come as well with severe toxicological side effects because of unwanted accumulation in organs outside of their targeted site of actions. Several studies showed an unintended accumulation of various nanocarriers in female sex organs, especially in the ovaries. Some led to inflammation, fibrosis, or decreasing follicle numbers. However, none of these studies investigated ovarian accumulation in context to both reproductive aging and particle size. Besides the influences of particle size, the biodistribution profile may be altered as well by reproductive aging because of reduced capacities of the reticuloendothelial system (RES), changes in sex steroid hormone levels as well as altering ovarian stromal blood flow. This systematic investigation of the biodistribution of intravenously (i.v) injected nanoemulsions revealed significant dependencies on the two parameters particle size and age starting from juvenile prepubescent to senescent mice. Using fluorescent in vivo and ex vivo imaging, prepubescent mice showed nearly no accumulation of nanoemulsion in their uteri and ovaries, but high accumulations in the organs of the RES liver and spleen independently of the particle size. In fertile adult mice, the accumulation increased significantly in the ovaries with an increased particle size of the nanoemulsions by nearly doubling the portion of the average radiant efficiency (PARE) to ~10% of the total measured signal of all excised organs. With reproductive aging and hence loss of fertility in senescent mice, the accumulation decreased again to moderate levels, again independently of the particle size. In conclusion, the ovarian accumulation of these nanocarriers depended on both the age plus the particle size during maturity.

Gold nanoparticle biodistribution in pregnant mice following intravenous administration varies with gestational age

The use of nanoparticles (NPs) to deliver therapeutics to reproductive organs is an emerging approach to safely and effectively treat mothers and babies facing pregnancy complications. This study investigates the biodistribution of two different sized gold-based NPs in pregnant mice following systemic delivery as a function of gestational age. Poly(ethylene glycol)-coated 15 nm gold nanoparticles or 150 nm diameter silica core/gold nanoshells were intravenously administered to pregnant mice at gestational days (E)9.5 or 14.5. NP distribution was analyzed twenty-four hours later by inductively coupled plasma-mass spectrometry and silver staining of histological specimens. More NPs accumulated in placentas than embryos and delivery to these tissues was greater at E9.5 than E14.5. Neither NP type affected fetal weight or placental weight, indicating minimal short-term toxicity in early to mid-stage pregnancy. These findings warrant continued development of NPs as tools to deliver therapeutics to reproductive tissues safely.

The biological synthesis of gold/perlite nanocomposite using Urtica dioica extract and its chitosan-capped derivative for healing wounds infected with methicillin-resistant Staphylococcus aureus

The preparation of ointments from natural compounds is essential for accelerating infected wounds. This study investigated the effects of topical uses of gold nanoparticles (Au)/perlite (Au/Perl) nanocomposites (NCs) by the help of Urtica dioica extract and its chitosan-capped derivative (Chit) on methicillin-resistant Staphylococcus aureus (MRSA)-infected wound healing in a mouse model. Furthermore, Au/Perl/Chit nanocomposite was prepared using protonated chitosan solution. The physicochemical properties of the as-synthesized nanocomposites were also investigated. The effects of Au/Perl/Chit NC were assessed by antibacterial, histopathological parameters as well as molecular evaluations. Then, they were compared with synthetic agent of mupirocin. The results revealed that Au/Perl NC was mesoporous and spherical in a range of 13-15 nm. Topical administration of Au/Perl/Chit ointment accelerated wound healing by reducing bacteria colonization and wound rate enhancing collagen biosynthesis and re-epithelialization, the expressions of IL-10, PI3K, AKT, bFGF, and COL1A genes, which is in agreement with the obtained results for mupirocin. In conclusion, the results strongly demonstrated that administration of ointments prepared from Au/Perl and Au/Perl/Chit nanocomposites stimulates MRSA-infected wound healing by decreasing the length of healing time and regulating PI3K/AKT/bFGF signaling pathway and is a promising candidate in stimulating MRSA-infected wound regeneration.

Co-delivery of doxorubicin and aptamer against Forkhead box M1 using chitosan-gold nanoparticles coated with nucleolin aptamer for synergistic treatment of cancer cells

Herein, a nanotherapeutic delivery method was presented for co-delivery of doxorubicin (DOX) and aptamer against Forkhead box M1 (FOXM1 Apt) to cancer cells. Firstly, the vehicle composed of chitosan (CS)-Gold nanoparticles (AuNPs) conjugate was prepared. Nucleolin aptamer (AS1411) and FOXM1 Apt were loaded onto the CS-AuNPs and formed Aptamers (Apts)-CS-AuNPs. Subsequently, DOX was added to the Apts-CS-AuNPs to obtain the DOX-Apts-CS-AuNPs complex for synergistic treatment of tumor. The data of flow cytometry analysis and fluorescence imaging displayed that the complex was effectively internalized into target cells (A549 and 4T1 cells, nucleolin+) but not into CHO cells as nontarget cells. The results of the MTT assay showed that the complex significantly increased cell mortality in 4T1 and A549 cells compared to CHO cells treated with the complex. The in vivo studies demonstrated that the DOX-Apts-CS-AuNPs complex exhibited more tumor inhibitory effect and less distribution in other organs compared to free DOX.

The challenge of using nanotherapy during pregnancy: Technological aspects and biomedical implications

During the period of pregnancy, several processes and physiological adaptations occur in the body and metabolism of pregnant woman. These physiological adaptations in pregnant woman end up leading to a suppression in immune system favoring obstetric complications to the mother, fetus and placental tissue. An effective pharmacological therapy for these complications is still a challenge, since some drugs during pregnancy can have deleterious and teratogenic effects. An emerging alternative to pharmacological therapy during pregnancy is drugs encapsulated in nanoparticles (NP), recent area called nano-obstetrics. NP have the advantage of drug targeting and reduction of side effects. Then, maternal, placental or fetal uptake can be expected, depending on the characteristics of NP. Inorganic NP, crossing placental barrier effectively, but have several nanotoxicological effects. While organic NP appear to have a better targeting capacity and have few toxicological effects, but the studies are still scarce. Thus, in this review, were examined questions related to use and impact of physicochemical aspects of inorganic and organic NP during pregnancy.

Plasma proteins facilitates placental transfer of polystyrene particles

Background

Nanoparticles, which are exposed to biological fluids are rapidly interacting with proteins and other biomolecules forming a corona. In addition to dimension, charge and material the distinct protein corona influences the interplay of nanoparticles with tissue barriers. In this study we were focused on the impact of in situ formed human plasma protein corona on the transfer of 80 nm polystyrene nanoparticles (PS-particles) across the human placenta. To study materno-to fetal PS transfer we used the human ex vivo placental perfusion approach, which represents an intact and physiological tissue barrier. To analyze the protein corona of PS particles we performed shotgun proteomics of isolated nanoparticles before and after tissue exposure.

Results

Human plasma incubated with PS-particles of 80 nm and subsequent formed protein corona enhanced the transfer across the human placenta compared to PS-corona formed by bovine serum albumin and dextran which served as a control. Quantitative and qualitative changes of plasma proteins determined the changes in PS transfer across the barrier. Based on the analysis of the PS-proteome two candidate proteins, namely human albumin and immunoglobulin G were tested if these proteins may account for the enhanced PS-transfer across the placenta. Interestingly, the protein corona formed by human albumin significantly induced the transfer of PS-particles across the tissue compared to the formed IgG-corona.

Conclusion

In total we demonstrate the PS corona dynamically and significantly evolves upon crossing the human placenta. Thus, the initial composition of PS particles in the maternal circulation is not predictive for their transfer characteristics and performance once beyond the barrier of the placenta. The precise mechanism of these effects remains to be elucidated but highlights the importance of using well designed biological models when testing nanoparticles for biomedical applications.

Design of nanomaterials for applications in maternal/fetal medicine

Pregnancy complications are commonplace and the challenges of treatment during pregnancy with few options available pose a risk to the health of both the mother and baby. Patients suffering from conditions such as preeclampsia, placenta accreta, and intrauterine growth restriction have few treatment options apart from emergency caesarean section. Fortunately, researchers are beginning to develop nanomedicine-based therapies that could be utilized to treat conditions affecting the mother, placenta, or fetus to improve the prognosis for mothers and their unborn children. This review summarizes the field's current understanding of nanoparticle biodistribution and therapeutic effect following systemic or vaginal administration and overviews the design parameters researchers should consider when developing nanomedicines for maternal/fetal health. It also describes safety considerations for nanomedicines to limit undesirable maternal or fetal side effects and discusses future work that should be performed to advance nanomedicine for maternal/fetal health. With additional development and implementation, the application of nanomedicine to treat pregnancy complications may mitigate the need for emergency caesarean sections and allow pregnancies to extend to term.

Curcumin-loaded poly(ϵ-caprolactone) lipid-core nanocapsules: Evaluation of fetal and maternal toxicity

This study was designed to examine fetal and maternal toxicity of curcumin (CURC) loaded lipid-core nanocapsules (LNC) prepared with poly(ϵ-caprolactone) as a polymer, administered during the organogenesis period. Free CURC and CURC loaded-LNC (C-LNC) (2 mg/kg), blank LNC (B-LNC) and saline (CONTROL) were administered per oral route from the 7° to 13° gestational day (GD). Dams were evaluated daily for body weight gain, clinical signs, water and food intake. On 20° GD, dams were euthanized, organs were weighed and blood was collected for biochemical determinations. Fetal biometrics and external morphological anomalies were assessed. Also, were performed histopathological analysis of placenta and measurement of cytokines levels in placental and fetal liver tissues. All groups did not cause changes in dams during the pregnancy. Furthermore, treatments did not cause external morphological changes and delayed fetal development. Still, for histopathological analysis of placental tissue, treatments did not cause alterations in evaluated parameters. For cytokines levels, CURC and C-LNC caused a decrease in placental levels of TNF-α. Therefore, we have demonstrated that C-LNC did not cause toxicological effects (mother and fetus), in the same manner as pattern bioactive compound, proving to be a promising nutraceutical delivery system for maternal supplementation with CURC.

DC-targeted gold nanoparticles as an efficient and biocompatible carrier for modulating allergic responses in sublingual immunotherapy

BACKGROUND

Sublingual immunotherapy (SLIT) was introduced to deliver allergens in an effective and non-invasive route, which can be considered as an alternative for allergen-specific subcutaneous immunotherapy (SCIT). On the other hand, the use of gold nanoparticles (AuNPs) in allergen delivery has beneficial effects on sublingual immunotherapy. In addition, the molecular targeting agents like aptamers (Apt), have been widely applied for targeted drug delivery. Therefore, the current study aimed to evaluate the effects of dendritic cells (DCs)-specific Aptamer-modified AuNPs coated with ovalbumin (OVA) on the improvement of the SLIT outcome in the mouse model of allergy.

MATERIAL AND METHODS

AuNPs with approximately 15 nm diameter were prepared by citrate reduction of HAuCl4. Afterward, Apt-modified AuNP complex was prepared and OVA was then loaded onto this complex. Following sensitization of Balb/c mice to OVA, SLIT was performed with Apt-AuNPs containing 5 µg OVA twice a week for a 2-month period. Allergen-specific IgE in serum, as well as cytokines secretion of spleen cells, were analyzed using ELISA. Also, nasopharyngeal lavage Fluid (NALF) was collected for total and eosinophil counts. Moreover, the lungs were removed for histopathological examination.

RESULTS

SLIT with Apt-modified AuNPs complex containing 5 μg OVA, decreased the IgE levels compared to the other groups. Also, IL-4 production has significantly decreased in spleen cells, while TGF-β and IFN-γ have significantly increased. The assessment of NALF in the group treated by this complex showed a decrease in total cell as well as in eosinophil count. Also, the examination of lung tissues revealed that, in the group treated by this complex, inflammation and perivascular infiltration were lesser than the other groups, which were observed in only one vessel of tissue.

CONCLUSION

It was shown that, Sublingual immunotherapy with DC specific Apt-modified AuNPs containing 5 μg OVA can improve the Th1 and Treg immunomodulatory responses.

Gold Nanoparticles Induce Oxidative Stress and Apoptosis in Human Kidney Cells

Gold nanoparticles (AuNPs) are highly attractive for biomedical applications. Therefore, several in vitro and in vivo studies have addressed their safety evaluation. Nevertheless, there is a lack of knowledge regarding their potential detrimental effect on human kidney. To evaluate this effect, AuNPs with different sizes (13 nm and 60 nm), shapes (spheres and stars), and coated with 11-mercaptoundecanoic acid (MUA) or with sodium citrate, were synthesized, characterized, and their toxicological effects evaluated 24 h after incubation with a proximal tubular cell line derived from normal human kidney (HK-2). After exposure, viability was assessed by the MTT assay. Changes in lysosomal integrity, mitochondrial membrane potential (ΔΨm), reactive species (ROS/RNS), intracellular glutathione (total GSH), and ATP were also evaluated. Apoptosis was investigated through the evaluation of the activity of caspases 3, 8 and 9. Overall, the tested AuNPs targeted mainly the mitochondria in a concentration-dependent manner. The lysosomal integrity was also affected but to a lower extent. The smaller 13 nm nanospheres (both citrate- and MUA-coated) proved to be the most toxic among all types of AuNPs, increasing ROS production and decreasing mitochondrial membrane potential (p ≤ 0.01). For the MUA-coated 13 nm nanospheres, these effects were associated also to increased levels of total glutathione (p ≤ 0.01) and enhanced ATP production (p ≤ 0.05). Programmed cell death was detected through the activation of both extrinsic and intrinsic pathways (caspase 8 and 9) (p ≤ 0.05). We found that the larger 60 nm AuNPs, both nanospheres and nanostars, are apparently less toxic than their smaller counter parts. Considering the results herein presented, it should be taken into consideration that even if renal clearance of the AuNPs is desirable, since it would prevent accumulation and detrimental effects in other organs, a possible intracellular accumulation of AuNPs in kidneys can induce cell damage and later compromise kidney function.

La2O3 Nanoparticles Induce Reproductive Toxicity Mediated by the Nrf-2/ARE Signaling Pathway in Kunming Mice

Purpose

Lanthanum oxide (La₂O₃) nanoparticles (NPs) have been widely used in catalytic and photoelectric applications, but the reproductive toxicity is still unclear. This study evaluated the reproductive toxicity of two different-sized La₂O₃ particles in the testes.

Materials and Methods

Fifty Kunming mice were randomly divided into five groups. Mice were treated with La₂O₃ NPs by repeated intragastric administration for 90 days (control, nano-sized with 5, 10, 50 mg/kg BW and micro-sized with 50 mg/kg BW). Mice in the control group were treated with de-ionised water without La₂O₃ NPs. Sperm parameters, testicular histopathology, TEM assessment, hormone assay and nuclear factor erythroid 2-related factor 2 (Nrf-2) pathway were performed and evaluated.

Results

The body weight of mice treated with La₂O₃ NPs or not had no difference; sperm parameters and histological assessment showed that La₂O₃ NPs could induce reproductive toxicity in the testicle. Serum testosterone and gonadotropin-releasing hormone (GnRH) in the NH (nano-sized with 50 mg/kg BW) group were markedly decreased relative to control group, and an increase of luteinizing hormone (LH) in NH group was detected . Additionally, transmission electron microscopy revealed that the ultrastructural abnormalities induced by La₂O₃ NPs were more severe than La₂O₃ MPs in the testes. Furthermore, La₂O₃ NPs treatment inhibited the translocation of nuclear factor erythroid 2-related factor 2 (Nrf-2) from the cytoplasm into the nucleus as well as the expression of downstream genes NAD(P)H quinone oxidoreductase1 (NQO1), hemeoxygenase 1 (HO-1) and (glutathione peroxidase) GSH-Px, thus abrogating Nrf-2-mediated defense mechanisms against oxidative stress.

Conclusions

The results of this study demonstrated that La₂O₃ NPs improved the spermatogenesis defects in mice. La₂O₃ NPs inhibited Nrf-2/ARE signaling pathway that resulted in apoptosis in the mice testes.

Development of a comprehensive understanding of aggregation-settling movement of CeO2 nanoparticles in natural waters

Parameters such as the settling rate, aggregation rate, and collision frequency in predictive models used to describe the fate of nanoparticles (NPs) are very important for the risk assessment of NPs in the environment. In this study, CeO₂ NPs were chosen as the model particles to investigate such parameters through aggregation-settling experiments under environmentally relevant conditions. The results indicate that natural colloids (Ncs) have no effect on the settling of NPs in seawaters, whereas they stabilize the NPs at a low initial particle concentration and promote the heteroaggregation of NPs at a high initial particle concentration in lake waters. In all cases, a suspended sediment absorbs the NPs and Ncs as mixed aggregates, resulting in a rapid settling. Furthermore, the calculation results of the model indicate that the shear force increases the collision frequency of the NPs by 4-5 orders of magnitude higher than that in quiescent waters. However, the break-up effect by the shear force is more obvious, namely, the shear force hinders the aggregation of NPs in natural waters, instead of promoting aggregation. Remarkably, a negative value of the dis-heteroaggregation rate based on the combined von Smoluchowski-Stokes equation can reflect the hindering effect on the aggregation process. The results of this study will provide scientific and accurate guidance for the parameter selection in the existing prediction model and contribute to a prediction of the fate and transport of NPs in the environment.

Redox Status, Hematological Parameters as Well Liver and Kidney Function Indicators in Blood of Chickens Receiving Gold Nanoparticles

The aim of the study was to assess the biocompatibility of gold nanoparticles (Au-NPs) for chickens by investigating their effect on their growth, hematological parameters, markers of oxidative stress, and indicators of liver and kidney function. The experiment was carried out on 54 chickens assigned to 3 experimental groups of 18 birds each. The control group did not receive gold nanoparticles. The birds in group Au-NPs2.0 received gold nanoparticles in a tube into a crop at a rate of 2.0 mg/kg body weight/day, while the birds in AuNPs5.0 group at a rate of 5.0 mg/kg body weight/day. The blood for analysis was collected after 7, 14, 21 and 28 days of Au-NPs application. The obtained results indicate that short-term (7–14 day) exposure to lower dose (2.0 mg/kg b.w./day) of AuNPs had no toxic impact on chickens, but the extension of the duration time caused toxicological effects evidenced by growth inhibition as well as induction of oxidative stress and liver injury. The higher dose of AuNPs (5.0 mg/kg b.w./day) exerted toxic effects already after 7–14 days of supplementation.

Murine exposure to gold nanoparticles during early pregnancy promotes abortion by inhibiting ectodermal differentiation

Background

Gold nanoparticles (AuNPs) have been widely studied for biomedical applications, although their safety and potential toxicity in pregnancy remains unknown. The aim of this study is to explore the effect of AuNPs maternal exposure at different gestational ages on fetal survival and development, as well as the potential mechanism of AuNPs affecting embryos and fetuses.

Methods

Thirty nm polyethylene glycol (PEG)-coated AuNPs (A30) were administered to pregnant mice via intravenous injection (5 μg Au/g body weight) over three days at either early or late pregnancy. Fetal abortion rate and morphological development in E16.5 were then detected in detail. The pregnant mice physiological states with A30 exposure were examined by biochemical, histological or imaging methods; and materno-fetal distribution of gold elements was assayed by electron microscopy and mass spectrometry. Murine embryonic stem cells derived embryoid-bodies or neuroectodermal cells were treated with A30 (0.0025 to 0.25 μg Au/mL) to examine A30 effects on expression levels of the germ differentiation marker genes. Tukey’s method was used for statistical analysis.

Results

Exposure to A30 during early (A30E) but not late (A30L) pregnancy caused a high abortion rate (53.5%), lower fetal survival rate and abnormal decidualization compared with non-exposed counterparts. The developmental damage caused by A30 followed an “all-or-nothing” pattern, as the non-aborted fetuses developed normally and pregnancies maintained normal endocrine values. A30 caused minor impairment of liver and kidney function of A30E but not A30L mice. TEM imaging of fetal tissue sections confirmed the transfer of A30 into fetal brain and live as aggregates. qPCR assays showed A30 suppressed the expression of ectodermal, but not mesodermal and endodermal differentiation markers.

Conclusions

These results illustrate that maternal A30 exposure in early pregnant results in A30 transfer into embryonic tissues, inhibiting ectodermal differentiation of embryonic stem cells, leading to abnormal embryonic development and abortion. While exposure to A30 during late pregnancy had little or no impact on dams and fetuses. These findings suggest the safety of biomedical applications employing AuNPs during pregnancy is strongly influenced by fetal maturity and gestational age at exposure and provide the clues for AuNPs safe application period in pregnancy.

Electronic supplementary material

The online version of this article (10.1186/s10020-018-0061-2) contains supplementary material, which is available to authorized users.

Antimicrobial activity and toxicity of gold nanoparticles: research progress, challenges and prospects

Gold nanoparticles are emerging materials that exhibit characteristics distinct from those of traditional materials and that have promising potential for application in the fields of chemistry, physics, biology and medicine. During the past decades, numerous studies on the antimicrobial activity and toxicity of gold nanoparticles have been published. With respect to antimicrobial activity, gold nanoparticles conjugated with small molecules, such as antibiotics, drugs, vaccines and antibodies, are more efficient than individual nanoparticles and molecules. Regarding the toxicity effects, results are often unclear and conflicting because of the lack of a standard experimental method; various studies have used different approaches, administration routes and doses, and similar experiments may lead to different conclusions. To provide a systematic overview of and insight in the current knowledge for researchers committed to this filed, we discuss the recent research advances related to the antimicrobial activity and toxicity of gold nanoparticles, both in vitro and in vivo, and identify major issues that require further study. SIGNIFICANCE AND IMPACT OF THE STUDY: This paper discusses the recent research progress on antimicrobial activity and toxicity of gold nanoparticles and provides general insights into the field for researchers committed to this field.

Copper Nanoparticles Show Obvious in vitro and in vivo Reproductive Toxicity via ERK Mediated Signaling Pathway in Female Mice

Copper nanoparticles (Cu-NPs) and other inorganic nanomaterials have caused increasing concern owing to be widely used. Early studies have reported that they can result in injuries to the kidney, liver and spleen of mice; cause embryonic damage; and inhibit the reproductive capacity of red worms. However, few studies have reported the toxicity of Cu-NPs on the reproductive systems of mammals. In the present work, we explored the cytotoxicity of Cu-NPs in human extravillous trophoblast cells and in the reproductive organs of mice. Cu-NPs induced ovarian and placental pathophysiology and dysfunction in mice. These nanoparticles also induced apoptosis and suppressed the proliferation of human extravillous trophoblast cells and caused cell cycle arrest at the G2/M phase in a time-and dose-dependent manner. Cu-NPs can significantly damage the mitochondrial membrane potential (MMP), which suggests that Cu-NPs can activate the mitochondria-mediated apoptosis signaling pathway. We also observed that Cu-NPs significantly inhibit the expression of BRAF, ERK, and MITF expression, all of which are important genes in the ERK signaling pathway. Our research demonstrated that Cu-NPs exert obvious reproductive toxicity in mice by disrupting the balance of sex hormones and exert cytotoxicity on human extravillous trophoblast cells, and ERK signaling and the mitochondrial apoptosis pathway made great contribution to the toxicity of Cu-NPs on female mice.

Toxic Effects of Size-tunable Gold Nanoparticles on Caenorhabditis elegans Development and Gene Regulation

We utilized size-tunable gold nanoparticles (Au NPs) to investigate the toxicogenomic responses of the model organism Caenorhabditis elegans. We demonstrated that the nematode C. elegans can uptake Au NPs coated with or without 11-mercaptoundecanoic acid (MUA), and Au NPs are detectable in worm intestines using X-ray microscopy and confocal optical microscopy. After Au NP exposure, C. elegans neurons grew shorter axons, which may have been related to the impeded worm locomotion behavior detected. Furthermore, we determined that MUA to Au ratios of 0.5, 1 and 3 reduced the worm population by more than 50% within 72 hours. In addition, these MUA to Au ratios reduced the worm body size, thrashing frequency (worm mobility) and brood size. MTT assays were employed to analyze the viability of cultured C. elegans primary neurons exposed to MUA-Au NPs. Increasing the MUA to Au ratios increasingly reduced neuronal survival. To understand how developmental changes (after MUA-Au NP treatment) are related to changes in gene expression, we employed DNA microarray assays and identified changes in gene expression (e.g., clec-174 (involved in cellular defense), cut-3 and fil-1 (both involved in body morphogenesis), dpy-14 (expressed in embryonic neurons), and mtl-1 (functions in metal detoxification and homeostasis)).

Radiosensitizing effects of different size bovine serum albumin-templated gold nanoparticles on H22 hepatoma-bearing mice

Aim: To evaluate intravenously injected bovine serum albumin-templated gold nanoparticles (BSA-GNPs) for radiosensitization effects on H22 hepatoma-bearing mice. Materials & methods: BSA-GNPs in different size were injected intravenously with a dose of 4 mg Au/kg. After 30 min injection, the tumor-bearing mice were irradiated with 5 Gy x-ray. Results: BSA-GNPs in 8, 50 and 187 nm were synthesized and have no obvious cytotoxicity to HeLa, HepG2 and HeCat cells when the concentration was up to 32 μM. And no obvious physiological injury of mice occurred when the intravenous injection dose was 4 mg Au/kg. In vivo study indicates 8 and 50 nm BSA-GNPs can inhibit tumor growth through inducing apoptosis in radiotherapy, with enhancement factors 1.93 and 2.02, respectively. Conclusion: BSA-GNPs in 8 and 50 nm are promising radiosensitizers in radiotherapy of subcutaneously transplanted hepatocarcinoma.

Towards a better understanding on aggregation behavior of CeO2 nanoparticles in different natural waters under flow disturbance

The fate of nanoparticles in natural waters is affected by the combination of various factors, especially the flow disturbance which plays a decisive role in the transport of nanoparticles. This study investigated the aggregation behavior of CeO₂ nanoparticles (NPs) in natural waters by using a unique instrument to simulate flow disturbance. The results indicated that, in the absence of a shear force, the CeO₂ NPs formed linear, chain-like aggregates in seawater, owing to the high IS, which compressed the electrical double layer of particles. On the other hand, the NPs formed more compact aggregates in lake water, owing to an ion bridge effect between the NPs and the dissolved organic matter (DOM). It was also found that shear forces affected the aggregation behavior of the NPs. A low shear force promoted the aggregation of the NPs by increasing the collision efficiency while the aggregates were broken by a high shear force. Remarkably, the NPs maintained their potential for continuous aggregation when the slow stirring was reintroduced, suggesting that the aggregates began to grow again under renewed stirring. The results of this study could help in predicting the fate and transport behavior of CeO₂ NPs in actual aquatic environments.

Exploring the in vivo toxicity of nanoparticles

Toxicological tests of a xenobiotic play a key role to determine the safety of the new compound before it reaches the market. In this review article, we describe the main types of toxicological studies that can be performed in vivo to detect a possible undesired effect of a xenobiotic with especial emphasis on the data available for the different types of nanoparticles. The different procedures described in this review allow to obtain valuable information about the possible toxic effects of a xenobiotic to minimize the possible risks for patients once the compound has been approved for therapeutic use.

Maternal-placental-fetal biodistribution of multimodal polymeric nanoparticles in a pregnant rat model in mid and late gestation

Multimodal polymeric nanoparticles have many exciting diagnostic and therapeutic applications, yet their uptake and passage by the placenta, and applications in the treatment of pregnancy complications have not been thoroughly investigated. In this work, the maternal-fetal-placental biodistribution of anionic and cationic multimodal poly(glycidyl methacrylate) (PGMA) nanoparticles in pregnant rats at mid (ED10) and late (ED20) gestation was examined. Fluorescently-labelled and superparamagnetic PGMA nanoparticles functionalized with/without poly(ethyleneimine) (PEI) were administered to pregnant rats at a clinically-relevant dose and biodistribution and tissue uptake assessed. Quantitative measurement of fluorescence intensity or magnetic resonance relaxometry in tissue homogenates lacked the sensitivity to quantify tissue uptake. Confocal microscopy, however, identified uptake by maternal organs and the decidua (ectoplacental cone) and trophoblast giant cells of conceptuses at ED10. At ED20, preferential accumulation of cationic vs. anionic nanoparticles was observed in the placenta, with PGMA-PEI nanoparticles localised mainly within the chorionic plate. These findings highlight the significant impact of surface charge and gestational age in the biodistribution of nanoparticles in pregnancy, and demonstrate the importance of using highly sensitive measurement techniques to evaluate nanomaterial biodistribution and maternal-fetal exposure.

Nanocaged platforms: modification, drug delivery and nanotoxicity. Opening synthetic cages to release the tiger

Nanocages (NCs) have emerged as a new class of drug-carriers, with a wide range of possibilities in multi-modality medical treatments and theranostics. Nanocages can overcome such limitations as high toxicity caused by anti-cancer chemotherapy or by the nanocarrier itself, due to their unique characteristics. These properties consist of: (1) a high loading-capacity (spacious interior); (2) a porous structure (analogous to openings between the bars of the cage); (3) enabling smart release (a key to unlock the cage); and (4) a low likelihood of unfavorable immune responses (the outside of the cage is safe). In this review, we cover different classes of NC structures such as virus-like particles (VLPs), protein NCs, DNA NCs, supramolecular nanosystems, hybrid metal-organic NCs, gold NCs, carbon-based NCs and silica NCs. Moreover, NC-assisted drug delivery including modification methods, drug immobilization, active targeting, and stimulus-responsive release mechanisms are discussed, highlighting the advantages, disadvantages and challenges. Finally, translation of NCs into clinical applications, and an up-to-date assessment of the nanotoxicology considerations of NCs are presented.

Chitosan nanoparticles and their Tween 80 modified counterparts disrupt the developmental profile of zebrafish embryos

Chitosan nanoparticles (CS-NPs) and their Tween 80 modified counterparts (TmCS-NPs) are among the most commonly used brain-targeted vehicles. However, their potential developmental toxicity is poorly understood. In this study, zebrafish embryos are introduced as an in vivo platform. Both NPs showed a dose-dependent increase in developmental toxicity (decreased hatching rate, increased mortality and incidences of malformation). Neurobehavioral changes included decreased spontaneous movement in TmCS-NP treated embryos and hyperactive effect in CS-NP treated larvae. Both NPs remarkably inhibited axonal development of primary and secondary motor neurons, and affected the muscle structure. Overall, this study demonstrated that CS-NPs and TmCS-NPs could affect embryonic development, disrupt neurobehavior of zebrafish larvae and affect muscle and neuron development, suggesting more attention on biodegradable chitosan nanoparticles.

Knowledge gaps between nanotoxicological research and nanomaterial safety

With the wide research and application of nanomaterials in various fields, the safety of nanomaterials attracts much attention. An increasing number of reports in the literature have shown the adverse effects of nanomaterials, representing the quick development of nanotoxicology. However, many studies in nanotoxicology have not reflected the real nanomaterial safety, and the knowledge gaps between nanotoxicological research and nanomaterial safety remain large. Considering the remarkable influence of biological or environmental matrices (e.g., biological corona) on nanotoxicity, the situation of performing nanotoxicological experiments should be relevant to the environment and humans. Given the possibility of long-term and low-concentration exposure of nanomaterials, the reversibility of and adaptation to nanotoxicity, and the transgenerational effects should not be ignored. Different from common pollutants, the specific analysis methodology for nanotoxicology need development and exploration furthermore. High-throughput assay integrating with omics was highlighted in the present review to globally investigate nanotoxicity. In addition, the biological responses beyond individual levels, special mechanisms and control of nanotoxicity deserve more attention. The progress of nanotoxicology has been reviewed by previous articles. This review focuses on the blind spots in nanotoxicological research and provides insight into what we should do in future work to support the healthy development of nanotechnology and the evaluation of real nanomaterial safety.

Surface capping and size-dependent toxicity of gold nanoparticles on different trophic levels

In the present study, the toxicity of gold nanoparticles (Au NPs) was evaluated on various trophic organisms. Bacteria, algae, cell line, and mice were used as models representing different trophic levels. Two different sizes (CIT30 and CIT40) and surface-capped (CIT30-polyvinyl pyrrolidone (PVP)-capped) Au NPs were selected. CIT30 Au NP aggregated more rapidly than CIT40 Au NP, while an additional capping of PVP (CIT30-PVP capped Au NP) was found to enhance its stability in sterile lake water medium. Interestingly, all the forms of NPs evaluated were stable in the cell culture medium during the exposure period. Size- and dose-dependent cytotoxicities were observed in both bacteria and algae, with a strong dependence on reactive oxygen species (ROS) generation and lactate dehydrogenase (LDH) release. CIT30-PVP capped Au NP showed a significant decrease in toxicity compared to CIT30 Au NP in bacteria and algae. In the SiHa cell line, dose- and exposure-dependent decline in cell viability were noted for all three types of Au NPs. In mice, the induction of DNA damage was size and dose dependent, and surface functionalization with PVP reduced the toxic effects of CIT30 Au NP. The exposure to CIT30, CIT40, and CIT30-PVP capped Au NPs caused an alteration of the oxidative stress-related endpoints in mice hepatocytes. The toxic effects of the gold nanoparticles were found to vary in diverse test systems, accentuating the importance of size and surface functionalization at different trophic levels.

Double targeting, controlled release and reversible delivery of daunorubicin to cancer cells by polyvalent aptamers-modified gold nanoparticles

Clinical use of daunorubicin (Dau) in treatment of leukemia has been restricted because of its cardiotoxicity. Targeted delivery of anticancer drugs could decrease their off-target effects and enhance their efficacy. In this study a modified polyvalent aptamers (PA)-Daunorubicin (Dau)-Gold nanoparticles (AuNPs) complex was designed and its efficacy was assessed in Molt-4 cells (human acute lymphoblastic leukemia T-cell, target). Dau was efficiently loaded (10.5 μM) onto 1mL of PA-modified AuNPs. Dau was released from the PA-Dau-AuNPs complex in a pH-sensitive manner (faster release at pH5.5). The results of flow cytometry analysis indicated that the PA-Dau-AuNPs complex was efficiently internalized into target cells, but not into nontarget cells. The results of MTT assay were consistent with the internalization data. PA-Dau-AuNPs complex had less cytotoxicity in U266 cells compared to Dau alone and even Apt-Dau-AuNPs complex. The PA-Dau-AuNPs complex had more cytotoxicity in Molt-4 cells compared to Dau alone and even Apt-Dau-AuNPs complex. Cytotoxicity of PA-Dau-AuNPs complex was effectively antagonized using antisense of polyvalent aptamers. In conclusion, the designed drug delivery system inherited the properties of efficient drug loading, tumor targeting, pH-dependent drug release and controllable delivery of Dau to tumor cells.

Tight junction between endothelial cells: the interaction between nanoparticles and blood vessels

Since nanoparticles are now widely applied as food additives, in cosmetics and other industries, especially in medical therapy and diagnosis, we ask here whether nanoparticles can cause several adverse effects to human health. In this review, based on research on nanotoxicity, we mainly discuss the negative influence of nanoparticles on blood vessels in several aspects and the potential mechanism for nanoparticles to penetrate endothelial layers of blood vessels, which are the sites of phosphorylation of tight junction proteins (claudins, occludins, and ZO (Zonula occludens)) proteins, oxidative stress and shear stress. We propose a connection between the presence of nanoparticles and the regulation of the tight junction, which might be the key approach for nanoparticles to penetrate endothelial layers and then have an impact on other tissues and organs.

Gestational nanomaterial exposures: microvascular implications during pregnancy, fetal development and adulthood

Air pollution particulate matter and engineered nanomaterials are encompassed in the broad definition of xenobiotic particles. While the effects of perinatal air pollution exposure have been investigated, elucidation of outcomes associated with nanomaterial exposure, the focus of this review, is still in its infancy. As the potential uses of nanomaterials, and therefore exposures, increase exponentially so does the need for thorough evaluation. Up to this point, the majority of research in the field of cardiovascular nanotoxicology has focused on the coronary and vascular reactions to pulmonary exposures in young adult, healthy, male models; however, as intentional and unintentional contacts persist, the non-pulmonary risks to under-represented populations become a critical concern. Development of the maternal-fetal circulation during successful mammalian gestation is one of the most unusual complex, dynamic, and acutely demanding physiological systems. Fetal development in a hostile gestational environment can lead to systemic alterations, which may encourage adult disease. Therefore, the purpose of this review is to highlight the few knowns associated with gestational engineered nanomaterial exposure segmented by physiological periods of development or systemic targets: preconception and maternal, gestational, fetal and progeny (Abstract figure). Overall, the limited studies currently available provide compelling evidence of maternal, fetal and offspring dysfunctions after engineered nanomaterial exposure. Understanding the mechanisms associated with these multigenerational effects may allow pregnant women to safely reap the benefits of nanotechnology-enabled products and assist in the implementation of exposure controls to protect the mother and fetus allowing for development of safety by design for engineered nanomaterials.

Therapeutic and safety considerations of nanoparticle-mediated drug delivery in pregnancy

Advances in nanotechnology have resulted in the design of effective, safe and tissue-selective nanocarriers for delivering therapeutics to treat malignancies, infections and other diseases. In pregnancy, nanoparticle-based drug formulations could have the potential to selectively target either the placenta and/or fetus, enabling ‘fetal-friendly’ drugs to be administered in pregnancy with minimal risk of off-target effects. A considerable amount of research has been carried out on maternal-placental-fetal nanoparticle uptake, transfer and toxicity using rodent and ex vivo models. However, the development of placental targeting strategies and the therapeutic evaluation of nanoformulations in pregnancy remains in its infancy. While some promising avenues are currently under investigation, much work is needed to bring the advantages of nanoparticle-based drug therapy in pregnancy to clinical reality.

Targeted and controlled release delivery of daunorubicin to T-cell acute lymphoblastic leukemia by aptamer-modified gold nanoparticles

Clinical administration of daunorubicin (Dau) in treatment of leukemia has been limited by its cardiotoxicity. Targeted delivery of chemotherapy drugs could reduce their side effects and increase the therapeutic efficacy of these drugs. Biocompatibility and large surface area of gold nanoparticles (AuNPs) make these nanoparticles great candidates for biomedical applications. In this study sgc8c aptamer (Apt)-Dau-AuNPs complex was designed and evaluated for treatment of Molt-4 cells (human acute lymphoblastic leukemia T-cell, target). Apt-Dau-AuNPs complex formation was analyzed by fluorometric analysis and gel retardation assay. Dau release profiles from the complex were evaluated in pHs 5.5 and 7.4. For cytotoxic studies (MTT assay) U266 (B lymphocyte human myeloma, nontarget) and Molt-4 cells (target) were treated with Dau Apt-Dau conjugate and Apt-Dau-AuNPs complex. Internalization was monitored by flow cytometry and confocal imaging. 12 μM Dau was efficiently loaded onto 1 mL of Apt-modified AuNPs. Dau was released from the complex in a pH-dependent manner (higher rate of release at pH 5.5). The results of flow cytometry analysis and confocal imaging showed that the complex was effectively internalized into Molt-4 cells, but not into U266 cells. The results of MTT assay also confirmed the internalization data. Apt-Dau-AuNPs complex was less cytotoxic in U266 cells compared to Dau alone and even Apt-Dau conjugate. The complex was more cytotoxic in target cells in comparison with Dau alone and even Apt-Dau conjugate. In conclusion, Apt-Dau-AuNPs complex was able to selectively target Molt-4 cells. Another advantage of this system was pH-dependent release of drug from the complex. Furthermore, this complex has characteristics which make it ideal for clinical use.

Size- and surface chemistry-dependent pharmacokinetics and tumor accumulation of engineered gold nanoparticles after intravenous administration

It is important and essential to study the pharmacokinetics and biodistribution of gold nanoparticles for safer and more efficient therapeutic purposes.