Engineered nanomaterial applications in perinatal therapeutics.

Engineered nanomaterials (ENM) are widely used in commercial, domestic, and more recently biomedical applications. While the majority of exposures to ENM are unintentional, biomedical platforms are being evaluated for use in individualized and/or tissue-targeted therapies. Treatments are often avoided during prenatal periods to reduce adverse effects on the developing fetus. The placenta is central to maternal-fetal medicine. Perturbation of placental functions can limit transfer of necessary nutrients, alter production of hormones needed during pregnancy, or allow undesired passage of xenobiotics to the developing fetus. The development of therapeutics to target specific maternal, placental, or fetal tissues would be especially important to reduce or circumvent toxicities. Therefore, this review will discuss the potential use of ENM in perinatal medicine, the applicable physiochemical properties of ENM in therapeutic use, and current methodologies of ENM testing in perinatal medicine, and identify maternal, fetal, and offspring concerns associated with ENM exposure during gestation. As potential nanoparticle-based therapies continue to develop, so does the need for thorough consideration and evaluation for use in perinatal medicine.

Maternal engineered nanomaterial inhalation during gestation alters the fetal transcriptome.

BACKGROUND: The integration of engineered nanomaterials (ENM) is well-established and widespread in clinical, commercial, and domestic applications. Cardiovascular dysfunctions have been reported in adult populations after exposure to a variety of ENM. As the diversity of these exposures continues to increase, the fetal ramifications of maternal exposures have yet to be determined. We, and others, have explored the consequences of ENM inhalation during gestation and identified many cardiovascular and metabolic outcomes in the F1 generation. The purpose of these studies was to identify genetic alterations in the F1 generation of Sprague-Dawley rats that result from maternal ENM inhalation during gestation. Pregnant dams were exposed to nano-titanium dioxide (nano-TiO2) aerosols (10 ± 0.5 mg/m3) for 7-8 days (calculated, cumulative lung deposition = 217 ± 1 µg) and on GD (gestational day) 20 fetal hearts were isolated. DNA was extracted and immunoprecipitated with modified chromatin marks histone 3 lysine 4 tri-methylation (H3K4me3) and histone 3 lysine 27 tri-methylation (H3K27me3). Following chromatin immunoprecipitation (ChIP), DNA fragments were sequenced. RNA from fetal hearts was purified and prepared for RNA sequencing and transcriptomic analysis. Ingenuity Pathway Analysis (IPA) was then used to identify pathways most modified by gestational ENM exposure. RESULTS: The results of the sequencing experiments provide initial evidence that significant epigenetic and transcriptomic changes occur in the cardiac tissue of maternal nano-TiO2 exposed progeny. The most notable alterations in major biologic systems included immune adaptation and organismal growth. Changes in normal physiology were linked with other tissues, including liver and kidneys. CONCLUSIONS: These results are the first evidence that maternal ENM inhalation impacts the fetal epigenome.

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.

Uterine microvascular sensitivity to nanomaterial inhalation: An in vivo assessment.

With the tremendous number and diverse applications of engineered nanomaterials incorporated in daily human activity, exposure can no longer be solely confined to occupational exposures of healthy male models. Cardiovascular and endothelial cell dysfunction have been established using in vitro and in situ preparations, but the translation to intact in vivo models is limited. Intravital microscopy has been used extensively to understand microvascular physiology while maintaining in vivo neurogenic, humoral, and myogenic control. However, a tissue specific model to assess the influences of nanomaterial exposure on female reproductive health has not been fully elucidated. Female Sprague Dawley (SD) rats were exposed to nano-TiO2 aerosols (171 ± 6 nm, 10.1 ± 0.39 mg/m(3), 5h) 24-hours prior to experimentation, leading to a calculated deposition of 42.0 ± 1.65 µg. After verifying estrus status, vital signs were monitored and the right horn of the uterus was exteriorized, gently secured over an optical pedestal, and enclosed in a warmed tissue bath using intravital microscopy techniques. After equilibration, significantly higher leukocyte-endothelium interactions were recorded in the exposed group. Arteriolar responsiveness was assessed using ionophoretically applied agents: muscarinic agonist acetylcholine (0.025 M; ACh; 20, 40, 100, and 200 nA), and nitric oxide donor sodium nitroprusside (0.05 M; SNP; 20, 40, and 100 nA), or adrenergic agonist phenylephrine (0.05 M; PE; 20, 40, and 100 nA) using glass micropipettes. Passive diameter was established by tissue superfusion with 10(-4)M adenosine. Similar to male counterparts, female SD rats present systemic microvascular dysfunction; however the ramifications associated with female health and reproduction have yet to be elucidated.

Single pulmonary nanopolystyrene exposure in late-stage pregnancy dysregulates maternal and fetal cardiovascular function.

Large-scale production and waste of plastic materials have resulted in widespread environmental contamination by the breakdown product of bulk plastic materials to micro- and nanoplastics (MNPs). The small size of these particles enables their suspension in the air, making pulmonary exposure inevitable. Previous work has demonstrated that xenobiotic pulmonary exposure to nanoparticles during gestation leads to maternal vascular impairments, as well as cardiovascular dysfunction within the fetus. Few studies have assessed the toxicological consequences of maternal nanoplastic (NP) exposure; therefore, the objective of this study was to assess maternal and fetal health after a single maternal pulmonary exposure to polystyrene NP in late gestation. We hypothesized that this acute exposure would impair maternal and fetal cardiovascular function. Pregnant rats were exposed to nanopolystyrene on gestational day 19 via intratracheal instillation. 24 h later, maternal and fetal health outcomes were evaluated. Cardiovascular function was assessed in dams using vascular myography ex vivo and in fetuses in vivo function was measured via ultrasound. Both fetal and placental weight were reduced after maternal exposure to nanopolystyrene. Increased heart weight and vascular dysfunction in the aorta were evident in exposed dams. Maternal exposure led to vascular dysfunction in the radial artery of the uterus, a resistance vessel that controls blood flow to the fetoplacental compartment. Function of the fetal heart, fetal aorta, and umbilical artery after gestational exposure was dysregulated. Taken together, these data suggest that exposure to NPs negatively impacts maternal and fetal health, highlighting the concern of MNPs exposure on pregnancy and fetal development.

Nanoparticles at the maternal-fetal interface.

The increasing production of intentional and unintentional nanoparticles (NPs) has led to their accumulation in the environment as air and ground pollution. The heterogeneity of these particles primarily relies on the NP physicochemical properties (i.e., chemical composition, size, shape, surface chemistry, etc.). Pregnancy represents a vulnerable life stage for both the woman and the developing fetus. The ubiquitous nature of these NPs creates a concern for developmental fetal exposures. At the maternal-fetal interface lies the placenta, a temporary endocrine organ that facilitates nutrient and waste exchange as well as communication between maternal and fetal tissues. Recent evidence in human and animal models identifies that gestational exposure to NPs results in placental translocation leading to local effects and endocrine disruption. Currently, the mechanisms underlying placental translocation and cellular uptake of NPs in the placenta are poorly understood. The purpose of this review is to assess the current understanding of the physiochemical factors influencing NP translocation, cellular uptake, and endocrine disruption at the maternal-fetal interface within the available literature.

Maternal, placental, and fetal distribution of titanium after repeated titanium dioxide nanoparticle inhalation through pregnancy.

Epidemiological studies have associated ambient engineered nanomaterials or ultrafine particulate matter (PM0.1), collectively referred to as nanoparticles (NPs), with adverse pregnancy outcomes including miscarriage, preterm labor, and fetal growth restriction. Evidence from non-pregnant models demonstrate that NPs can cross the lung air-blood barrier and circulate systemically. Therefore, inhalation of NPs during pregnancy leading to fetoplacental exposure has garnered attention. The purpose of this study was to evaluate the distribution of inhaled titanium dioxide nanoparticles (nano-TiO2) from the maternal lung to maternal and fetal systemic tissues. Pregnant Sprague Dawley rats were administered whole-body exposure to filtered air or of nano-TiO2 aerosols (9.96 ± 0.06 mg/m3) between gestational day (GD) 4 and 19. On GD 20 maternal, placental, and fetal tissues were harvested then digested for ICP-MS analysis to measure concentrations of titanium (Ti). TEM was used to visualize particle internalization by the placental syncytium. The results demonstrate the extrapulmonary distribution of Ti to various maternal organs during pregnancy. Our study found Ti accumulation in the decidua/junctional and labyrinth zones of placentas embedded in all sections of uterine horns. Further, NPs deposited in the placenta, identified by TEM, were found intracellularly within nuclear, endoplasmic reticulum, and vesicle organelles. This study identified the systemic distribution and placental accumulation of Ti after nano-TiO2 aerosol inhalation in a pregnancy model. These findings arouse concerns for poor air quality for pregnant women and possible contributions to adverse pregnancy outcomes.

Micro- and nanoplastic transfer, accumulation, and toxicity in humans.

Plastics impact our daily lives. Unfortunately, it is the disuse and disposal of these items that may affect us the greatest. Plastic micro- and nanosized particles, likely from bulk degradation, have been identified in air pollution and water sources. Recently, plastic particles have also been identified in consumable products. The purpose of this review is to identify the likely routes of human exposure, the toxicological outcomes and concerns currently reported, and to provide some considerations for future assessments.

Considering intrauterine location in a model of fetal growth restriction after maternal titanium dioxide nanoparticle inhalation.

Fetal growth restriction (FGR) is a condition with several underlying etiologies including gestational disease (e.g., preeclampsia, gestational diabetes) and xenobiotic exposure (e.g., environmental contaminants, pharmaceuticals, recreational drugs). Rodent models allow study of FGR pathogenesis. However, given the multiparous rodent pregnancy, fetal growth variability within uterine horns may arise. To ascertain whether intrauterine position is a determinant of fetal growth, we redesigned fetal weight analysis to include litter size and maternal weight. Our FGR model is produced by exposing pregnant Sprague Dawley rats to aerosolized titanium dioxide nanoparticles at 9.44 ± 0.26 mg/m3 on gestational day (GD) 4, GD 12 or GD 17 or 9.53 ± 1.01 mg/m3 between GD 4-GD 19. In this study fetal weight data was reorganized by intrauterine location [i.e., right/left uterine horn and ovarian/middle/vaginal position] and normalized by maternal weight and number of feti per uterine horn. A significant difference in fetal weight in the middle location in controls (0.061g ± 0.001 vs. 0.055g ± 0.002), GD 4 (0.033g ± 0.003 vs. 0.049g ± 0.004), and GD 17 (0.047g ± 0.002 vs. 0.038g ± 0.002) exposed animals was identified. Additionally, GD 4 exposure produced significantly smaller feti in the right uterine horn at the ovarian end (0.052g ± 0.003 vs. 0.029g ± 0.003) and middle of the right uterine horn (0.060g ± 0.001 vs. 0.033g ± 0.003). GD 17 exposure produced significantly smaller feti in the left uterine horn middle location (0.055g ± 0.002 vs. 0.033 ± 0.002). Placental weights were unaffected, and placental efficiency was reduced in the right uterine horn middle location after GD 17 exposure (5.74g ± 0.16 vs. 5.09g ± 0.14). These findings identified: 1) differences in fetal weight of controls between the right and left horns in the middle position, and 2) differential effects of single whole-body pulmonary exposure to titanium dioxide nanoparticles on fetal weight by position and window of maternal exposure. In conclusion, these results indicate that consideration for intrauterine position, maternal weight, and number of feti per horn provides a more sensitive assessment of FGR from rodent reproductive and developmental studies.

Toxicological considerations of nano-sized plastics.

Undoubtedly, plastics have changed human existence. These pervasive products are used in nearly every field to include technological, biomedical, and domestic applications. Post-consumer plastic waste disposal leading to plastic pollution in landfills, waterways, and oceans represents a worldwide environmental challenge. Accumulation and continued material fragmentation from micro- to nanoplastics has identified concerns pertaining to environmental and human exposures and toxicity. While many studies have focused on particle fate and identification, the toxicological considerations must focus on the biological relevance of particle deposition within a particular organism, compartment, organ, and tissue. Further, concerns exist regarding the physical and chemical properties of the plastic particles during their production and/or degradation. In this mini-review we will discuss (1) particle characterization and assessment, (2) environmental concerns, and (3) human toxicity.

Effect of Gestational Age on Maternofetal Vascular Function Following Single Maternal Engineered Nanoparticle Exposure.

Normal pregnancy outcome is accomplished, in part, by rapid and expansive physiological adaptations to the systemic circulation, the extent of which is specific to gestational day (GD) and anatomical location. Pregnancy-related hemodynamic changes in uterine placental blood flow stimulate compensatory vascular signaling and remodeling that begins early and continues throughout gestation. Exposure of the maternal environment to engineered nanomaterials (ENM) during pregnancy has been shown to impact health of the dam, fetus, and adult offspring; however, the consequences of specific temporal (gestational age) and spatial (vascular location) considerations are largely undetermined. We exposed pregnant Sprague-Dawley rats to nano-TiO2 aerosols at three critical periods of fetal development (GD 4, 12, and 17) to identify vascular perturbations associated with ENM exposure at these developmental milestones. Vascular reactivity of the maternal thoracic aorta, the uterine artery, the umbilical vein, and the fetal thoracic aorta were evaluated using wire myography on GD 20. While impairments were noted at each level of the maternofetal vascular tree and at each exposure day, our results indicate the greatest effects may be identified within the fetal vasculature (umbilical vein and fetal aorta), wherein effects of a single maternal inhalational exposure to nano-TiO2 on GD 4 modified responses to cholinergic, NO, and α-adrenergic signaling.

Identification and quantification of gold engineered nanomaterials and impaired fluid transfer across the rat placenta via ex vivo perfusion.

Development and implementation of products incorporating nanoparticles are occurring at a rapid pace. These particles are widely utilized in domestic, occupational, and biomedical applications. Currently, it is unclear if pregnant women will be able to take advantage of the potential biomedical nanoproducts out of concerns associated with placental transfer and fetal interactions. We recently developed an ex vivo rat placental perfusion technique to allow for the evaluation of xenobiotic transfer and placental physiological perturbations. In this study, a segment of the uterine horn and associated placenta was isolated from pregnant (gestational day 20) Sprague-Dawley rats and placed into a modified pressure myography vessel chamber. The proximal and distal ends of the maternal uterine artery and the vessels of the umbilical cord were cannulated, secured, and perfused with physiological salt solution (PSS). The proximal uterine artery and umbilical artery were pressurized at 80 mmHg and 50 mmHg, respectively, to allow countercurrent flow through the placenta. After equilibration, a single 900 µL bolus dose of 20 nm gold engineered nanoparticles (Au-ENM) was introduced into the proximal maternal artery. Distal uterine and umbilical vein effluents were collected every 10 min for 180 min to measure placental fluid dynamics. The quantification of Au-ENM transfer was conducted via inductively coupled plasma mass spectrometry (ICP-MS). Overall, we were able to measure Au-ENM within uterine and umbilical effluent with 20 min of material infusion. This novel methodology may be widely incorporated into studies of pharmacology, toxicology, and placental physiology.

Estrous cycle-dependent modulation of in vivo microvascular dysfunction after nanomaterial inhalation.

Preconceptive health encompasses male and female reproductive capability. In females, this takes into account each of the stages of the estrous cycle. Microvascular reactivity varies throughout the estrous cycle in response to hormonal changes and in preparation for pregnancy. Microvascular alterations in response to engineered nanomaterial (ENM) exposure have been described within 24-h of inhalation; however, the impact upon the uterine vasculature at differing estrous stages and at late-stage pregnancy is unclear. Female Sprague Dawley (SD) rats (virgin and late stage pregnancy [GD 19]) were exposed to nano-TiO aerosols (173.2 ±â€¯6.4 nm, 10.2 ±â€¯0.46 mg/m3, 5 h) 24-h prior to experimentation leading to a single calculated deposition of 42.2 ±â€¯1.9 µg nano- TiO2 (exposed) or 0 µg (control). Animals were anesthetized, estrous status verified, and prepared for in situ assessment of leukocyte trafficking and vascular function by means of intravital microscopy, Uterine basal arteriolar reactivity was stimulated using iontophoretically applied chemicals: acetylcholine (ACh, 0.025 M; 20, 40, 100, 200 nA), sodium nitroprusside (SNP, 0.05 M; 20, 40, 100 nA), phenylephrine (PE, 0.05 M; 20, 40, 100 nA). Finally, adenosine (ADO, 10-4 M) was superfused over the tissue to identify maximum diameter. In situ vessel reactivity after exposure was significantly blunted based on estrous stage, but not at late-stage pregnancy. Local uterine venular leukocyte trafficking and systemic inflammatory markers were also significantly affected during preparatory (proestrus), fertile (estrus), and infertile (diestrus) periods after ENM inhalation. Overall, these deficits in reactivity and increased inflammatory activity may impair female fertility after ENM exposure.