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

The Application of Engineered Nanomaterials in Perinatal Therapeutics

Pregnancy is a vulnerable life stage for the mother and developing fetus. Because of this dual concern, approved therapeutic options for pre-existing conditions or pregnancy-induced pathologies, placental deformities, or fetal concerns are extremely limited. These cases often leave patients and clinicians having to choose between maternal health and fetal development. Recent advancements in nanomedicine and nanotherapeutic devices have made the development of perinatal therapeutics an attractive objective. However, perinatal medicine requires a multifaceted approach given the interactions between maternal, placental, and fetal physiology. Maternal-fetal interactions are centralized to the placenta, a specialized transient barrier organ, to allow for nutrient and waste exchange. Perinatal nanotherapeutics must be designed for placental avoidance or uptake. In this review, pregnancy-related conditions, experimental models, and modes of drug delivery during pregnancy are discussed.

Associations between Non-Essential Trace Elements in Women's Biofluids and IVF Outcomes in Euploid Single-Embryo Transfer Cycles

Previous studies have found inconsistent associations between heavy metals and metalloids (cadmium, lead, mercury, and arsenic), and reproductive outcomes. The biofluid concentrations of ten non-essential trace elements (Hg, Pb, As, Ba, Sr, Rb, Cs, Sn, Ni, and Co) were evaluated in 51 Spanish women undergoing ICSI, PGT-A, and SET/FET. Nine out of ten non-essential elements were detectable in follicular fluid, whole blood, and urine collected the day of vaginal oocyte retrieval (VOR) and the day of embryo transfer and then analyzed by ICP-MS or Tricell DMA-80 for mercury. Elevated mercury and strontium concentrations in follicular fluid were associated with poor ovarian response and preimplantation outcomes. Worst preimplantation outcomes were also identified in women with elevated whole-blood strontium or mercury, urinary arsenic, barium, and tin the day of VOR. High concentrations of urinary rubidium on VOR day were linked with enhanced fertilization and blastocyst development. Excessive titanium in whole blood was associated with lower odds of implantation, clinical pregnancy, and achieving a live birth in a given IVF cycle. Excessive urinary arsenic on the day of embryo transfer was associated with lower odds of live birth. Although these preliminary results need to be confirmed in larger populations, distinguishing organic and inorganic element forms, our findings show that some non-essential elements have a detrimental impact on human IVF outcomes.

Guidelines for in vivo models of developmental programming of cardiovascular disease risk

Research using animals depends on the generation of offspring for use in experiments or for the maintenance of animal colonies. Although not considered by all, several different factors preceding and during pregnancy, as well as during lactation, can program various characteristics in the offspring. Here, we present the most common models of developmental programming of cardiovascular outcomes, important considerations for study design, and provide guidelines for producing and reporting rigorous and reproducible cardiovascular studies in offspring exposed to normal conditions or developmental insult. These guidelines provide considerations for the selection of the appropriate animal model and factors that should be reported to increase rigor and reproducibility while ensuring transparent reporting of methods and results.

Inhaled Pollutants of the Gero-Exposome and Later-Life Health

Inhaled air pollutants (AirP) comprise extraordinarily diverse particles, volatiles, and gases from traffic, wildfire, cigarette smoke, dust, and various other sources. These pollutants contain numerous toxic components, which collectively differ in relative levels of components, but broadly share chemical classes. Exposure and health outcomes from AirP are complex, depending on pollutant source, duration of exposure, and socioeconomic status. We discuss examples in the current literature on organ responses to AirP, with a focus on lung, arteries, and brain. Some transcriptional responses are shared. It is well accepted that AirP contributes to Alzheimer's disease and other neurodegenerative conditions in the Gero-Exposome. However, we do not know which chemical compounds initiate these changes and how activation of these transcriptional pathways is further modified by genetics and prenatal development.

New trends on personalized sunscreens

BACKGROUND/PURPOSE

Nowadays, there are emerging trends in customized and personalized photoprotection, focusing on the innovative approaches to enhance sun protection efficacy tailored to individual needs.

METHODS

We conducted an electronic search of the following databases: MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Cochrane Skin Group Specialised Skin Register, and TESEO. Specific search terms related to personalized photoprotection and the variables of age, genetic predisposition, skin phototype, photodermatosis, and physiological conditions such as pregnancy, as well as lifestyle habits were used.

RESULTS/CONCLUSION

The article highlights the challenges and opportunities in adopting personalized photoprotection strategies, aiming to promote skin health and prevent the harmful effects of UV radiation in the era of precision medicine.

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.

The bio-distribution, clearance pathways, and toxicity mechanisms of ambient ultrafine particles

Ambient particles severely threaten human health worldwide. Compared to larger particles, ultrafine particles (UFPs) are highly concentrated in ambient environments, have a larger specific surface area, and are retained for a longer time in the lung. Recent studies have found that they can be transported into various extra-pulmonary organs by crossing the air-blood barrier (ABB). Therefore, to understand the adverse effects of UFPs, it is crucial to thoroughly investigate their bio-distribution and clearance pathways in vivo after inhalation, as well as their toxicological mechanisms. This review highlights emerging evidence on the bio-distribution of UFPs in pulmonary and extra-pulmonary organs. It explores how UFPs penetrate the ABB, the blood-brain barrier (BBB), and the placental barrier (PB) and subsequently undergo clearance by the liver, kidney, or intestine. In addition, the potential underlying toxicological mechanisms of UFPs are summarized, providing fundamental insights into how UFPs induce adverse health effects.

Determinants and mechanisms of inorganic nanoparticle translocation across mammalian biological barriers

Biological barriers protect delicate internal tissues from exposures to and interactions with hazardous materials. Primary anatomical barriers prevent external agents from reaching systemic circulation and include the pulmonary, gastrointestinal, and dermal barriers. Secondary barriers include the blood-brain, blood-testis, and placental barriers. The tissues protected by secondary barriers are particularly sensitive to agents in systemic circulation. Neurons of the brain cannot regenerate and therefore must have limited interaction with cytotoxic agents. In the testis, the delicate process of spermatogenesis requires a specific milieu distinct from the blood. The placenta protects the developing fetus from compounds in the maternal circulation that would impair limb or organ development. Many biological barriers are semi-permeable, allowing only materials or chemicals, with a specific set of properties, that easily pass through or between cells. Nanoparticles (particles less than 100 nm) have recently drawn specific concern due to the possibility of biological barrier translocation and contact with distal tissues. Current evidence suggests that nanoparticles translocate across both primary and secondary barriers. It is known that the physicochemical properties of nanoparticles can affect biological interactions, and it has been shown that nanoparticles can breach primary and some secondary barriers. However, the mechanism by which nanoparticles cross biological barriers has yet to be determined. Therefore, the purpose of this review is to summarize how different nanoparticle physicochemical properties interact with biological barriers and barrier products to govern translocation.

Transcriptomic profiling reveals differential cellular response to copper oxide nanoparticles and polystyrene nanoplastics in perfused human placenta

The growing nanoparticulate pollution (e.g. engineered nanoparticles (NPs) or nanoplastics) has been shown to pose potential threats to human health. In particular, sensitive populations such as pregnant women and their unborn children need to be protected from harmful environmental exposures. However, developmental toxicity from prenatal exposure to pollution particles is not yet well studied despite evidence of particle accumulation in human placenta. Our study aimed to investigate how copper oxide NPs (CuO NPs; 10-20 nm) and polystyrene nanoplastics (PS NPs; 70 nm) impact on gene expression in ex vivo perfused human placental tissue. Whole genome microarray analysis revealed changes in global gene expression profile after 6 h of perfusion with sub-cytotoxic concentrations of CuO (10 µg/mL) and PS NPs (25 µg/mL). Pathway and gene ontology enrichment analysis of the differentially expressed genes suggested that CuO and PS NPs trigger distinct cellular response in placental tissue. While CuO NPs induced pathways related to angiogenesis, protein misfolding and heat shock responses, PS NPs affected the expression of genes related to inflammation and iron homeostasis. The observed effects on protein misfolding, cytokine signaling, and hormones were corroborated by western blot (accumulation of polyubiquitinated proteins) or qPCR analysis. Overall, the results of the present study revealed extensive and material-specific interference of CuO and PS NPs with placental gene expression from a single short-term exposure which deserves increasing attention. In addition, the placenta, which is often neglected in developmental toxicity studies, should be a key focus in the future safety assessment of NPs in pregnancy.

Placental-fetal distribution of carbon particles in a pregnant rabbit model after repeated exposure to diluted diesel engine exhaust

BACKGROUND

Airborne pollution particles have been shown to translocate from the mother's lung to the fetal circulation, but their distribution and internal placental-fetal tissue load remain poorly explored. Here, we investigated the placental-fetal load and distribution of diesel engine exhaust particles during gestation under controlled exposure conditions using a pregnant rabbit model. Pregnant dams were exposed by nose-only inhalation to either clean air (controls) or diluted and filtered diesel engine exhaust (1 mg/m³) for 2 h/day, 5 days/week, from gestational day (GD) 3 to GD27. At GD28, placental and fetal tissues (i.e., heart, kidney, liver, lung and gonads) were collected for biometry and to study the presence of carbon particles (CPs) using white light generation by carbonaceous particles under femtosecond pulsed laser illumination.

RESULTS

CPs were detected in the placenta, fetal heart, kidney, liver, lung and gonads in significantly higher amounts in exposed rabbits compared with controls. Through multiple factor analysis, we were able to discriminate the diesel engine exposed pregnant rabbits from the control group taking all variables related to fetoplacental biometry and CP load into consideration. Our findings did not reveal a sex effect, yet a potential interaction effect might be present between exposure and fetal sex.

CONCLUSIONS

The results confirmed the translocation of maternally inhaled CPs from diesel engine exhaust to the placenta which could be detected in fetal organs during late-stage pregnancy. The exposed can be clearly discriminated from the control group with respect to fetoplacental biometry and CP load. The differential particle load in the fetal organs may contribute to the effects on fetoplacental biometry and to the malprogramming of the fetal phenotype with long-term effects later in life.

Lessons from the history of inorganic nanoparticles for inhalable diagnostics and therapeutics

The respiratory tract is one of the most accessible ones to exogenous nanoparticles, yet drug delivery by their means to it is made extraordinarily challenging because of the plexus of aerodynamic, hemodynamic and biomolecular factors at cellular and extracellular levels that synergistically define the safety and efficacy of this process. Here, the use of inorganic nanoparticles (INPs) for inhalable diagnostics and therapies of the lung is viewed through the prism of the history of studies on the interaction of INPs with the lower respiratory tract. The most conceptually and methodologically innovative and illuminative studies are referred to in the chronological order, as they were reported in the literature, and the trends in the progress of understanding this interaction of immense therapeutic and toxicological significance are being deduced from it. The most outstanding actual trends delineated include the diminishment of toxicity via surface functionalization, cell targeting, tagging and tracking via controlled binding and uptake, hybrid INP treatments, magnetic guidance, combined drug and gene delivery, use as adjuvants in inhalable vaccines, and other. Many of the understudied research directions, which have been accomplished by the nanostructured organic polymers in the pulmonary niche, are discussed. The progress in the use of INPs as inhalable diagnostics or therapeutics has been hampered by their well-recognized inflammatory potential and toxicity in the respiratory tract. However, the annual numbers of methodologically innovative studies have been on the rise throughout the past two decades, suggesting that this is a prolific direction of research, its comparatively poor commercial takings notwithstanding. Still, the lack of consensus on the effects of many INP compositions at low but therapeutically effective doses, the plethora of contradictory reports on ostensibly identical chemical compositions and NP properties, and the many cases of antagonism in combinatorial NP treatments imply that the rational design of inhalable medical devices based on INPs must rely on qualitative principles for the most part and embrace a partially stochastic approach as well. At the same time, the fact that the most studied INPs for pulmonary applications have been those with some of the thickest records of pulmonary toxicity, e.g., carbon, silver, gold, silica and iron oxide, is a silent call for the expansion of the search for new inorganic compositions for use in inhalable therapies to new territories.

Chronic maternal exposure to titanium dioxide nanoparticles alters breathing in newborn offspring

Background

Over the last two decades, nanotechnologies and the use of nanoparticles represent one of the greatest technological advances in many fields of human activity. Particles of titanium dioxide (TiO₂) are one of the nanomaterials most frequently found in everyday consumer products. But, due in particular to their extremely small size, TiO₂ nanoparticles (NPs) are prone to cross biological barriers and potentially lead to adverse health effects. The presence of TiO₂ NPs found in human placentae and in the infant meconium has indicated unequivocally the capacity for a materno-fetal transfer of this nanomaterial. Although chronic exposure to TiO₂ NPs during pregnancy is known to induce offspring cognitive deficits associated with neurotoxicity, the impact of a gestational exposure on a vital motor function such as respiration, whose functional emergence occurs during fetal development, remains unknown.

Results

Using in vivo whole-body plethysmographic recordings from neonatal mice, we show that a chronic exposure to TiO₂ NPs during pregnancy alters the respiratory activity of offspring, characterized by an abnormally elevated rate of breathing. Correspondingly, using ex vivo electrophysiological recordings performed on isolated brainstem-spinal cord preparations of newborn mice and medullary slice preparations containing specific nuclei controlling breathing frequency, we show that the spontaneously generated respiratory-related rhythm is significantly and abnormally accelerated in animals prenatally exposed to TiO₂ NPs. Moreover, such a chronic prenatal exposure was found to impair the capacity of respiratory neural circuitry to effectively adjust breathing rates in response to excitatory environmental stimuli such as an increase in ambient temperature.

Conclusions

Our findings thus demonstrate that a maternal exposure to TiO₂ NPs during pregnancy affects the normal development and operation of the respiratory centers in progeny.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12989-022-00497-4.