A method for evaluating and predicting placental transfer efficiency

Abstract

The present invention discloses a method for evaluating and predicting placental transport efficiency, comprising the following steps: S1: respectively measuring and analyzing PFASs in different test samples; S2: TTE estimation: calculating TTE0 and TTE(tem) according to the following formula: TTE0=C PFAS‑脐带血清 / C PFAS‑母体血清 、C PFAS‑母体血 ×V 母体血 ×TTE m =C PFAS ‑ 脐带血 ×V 脐带血 、C PFAS‑血清 / R=C PFAS‑全血 S3: Statistical Analysis. The present invention successfully identified differences in TTE between SGA infants and matched healthy controls using an improved TEM model that considers total PFAS exposure. The improved TEM model exhibited advantages in active transport and facilitated diffusion.

Description

Technical Field

[0001] The present invention belongs to the field of biomedicine, and in particular relates to an evaluation method and a prediction model for placental transport efficiency. Background Art

[0002] Perfluoroalkyl substances and polyfluoroalkyl substances (PFASs) are a large class of anthropogenic fluorinated chemicals that have been widely used in various industrial and consumer products. PFASs are persistent, bioaccumulative, and transportable, resulting in their widespread presence in the environment, wildlife, and humans. Due to the ubiquity of PFAS chemicals, they are detected frequently in the human population, and their adverse health consequences on humans have become a research hotspot. An increasing number of studies have confirmed that the main isomers of PFASs, perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), are toxic to animal development, neurobehavior, and the immune system. However, exposure to common PFAS congeners has negative effects on human health, especially on vulnerable groups including pregnant women and children, which remains to be fully explored.

[0003] Birth weight can be used as a surrogate indicator of fetal growth and development and is closely related to neonatal morbidity and mortality. Although it has been shown that PFAS exposure can induce fetal growth restriction in mammals, the relationship between PFAS exposure and human fetal birth weight is uncertain. Most studies have shown a negative correlation between PFAS and / or PFOS exposure during pregnancy and birth weight (or size), but not all results are statistically significant, and some studies have reported the opposite conclusion. Small for gestational age (SGA) is an adverse health symptom related to birth weight and is a recognized indicator of fetal growth restriction, but it has rarely been studied and reported.

[0004] The human placenta is crucial to the development of the fetus. It is a channel connecting the mother and the fetus, used to regulate oxygen, transport nutrients and metabolites. Existing studies have shown that PFASs can cross the placental barrier and be delivered to the developing fetus, showing different placental transport efficiencies (TTE). TTE is crucial for evaluating the barrier and transfer functions of the placenta and the risks of prenatal chemical exposure to fetal development and birth outcomes. TTE is affected not only by physical and chemical properties, but also by biological and physiological factors. The TTE estimation method in the prior art is only calculated based on the ratio of the concentration of a certain chemical in umbilical cord serum (or plasma) to the concentration of a certain chemical in maternal serum (or plasma). The calculation formula is as follows: TTE0=C PEAS-脐带血清 / C PFAS-母体血清The inventors discovered that PFAS chemicals can actually cross the placenta in multiple ways, not just passive transport, but also active transport or facilitated diffusion. However, the model TTE0, which is based on a simple ratio of the concentration of the test chemical in the umbilical cord to that in maternal serum, misses key health or biological information from both the mother and the fetus. Therefore, this model needs to be improved. Summary of the Invention

[0005] In response to the shortcomings of the existing technology, the purpose of the present invention is to provide an improved method and system for evaluating the placental transfer efficiency of PFAS chemicals, taking into account the total content of PFASs in the whole blood from the mother to the fetus, and selecting small for gestational age (SGA) birth as a "model disease" related to prenatal exposure to PFASs, and collecting maternal and fetal serum of SGA and appropriate for gestational age (i.e., matched healthy group, AGA) as research samples; the technical problems it solves are: based on a large population birth cohort in China, determining and comparing the concentrations of PFASs in maternal and umbilical cord blood at birth of AGA and SGA; using a new method to estimate the placental transfer efficiency of PFASs, and exploring the differences in placental transfer efficiency between AGA and SGA, providing theoretical support for further research on the distribution mechanism of PFAS in the human body and the relationship between prenatal PFASs exposure and fetal growth. However, the present invention does not involve direct diagnosis and treatment, but rather provides intermediate results for the prediction of later fetal growth.

[0006] The technical solution of the present invention is summarized as follows:

[0007] A first aspect of the present invention relates to a method for evaluating the placental transport efficiency of PFAS chemicals, comprising the following steps:

[0008] S1: Determination and analysis of PFASs in different test samples: add internal standard mixture to different test samples, then ultrasonically extract with acetonitrile-methanol mixture (V / V=1 / 1), precipitate at -20°C for 2h, discard the supernatant and dry, then add the resulting precipitate to methanol-water mixture (V / V=1 / 1), stir and disperse, concentrate and use ultra-performance liquid chromatography and triple quadrupole mass spectrometry to determine PFASs; different test samples include umbilical cord serum, maternal serum, umbilical cord blood, and maternal blood;

[0009] S2: TTE estimation:

[0010] Calculate TTE0 according to Formula 1:

[0011] TTE0=C PFAS-脐带血清 / C PFAS-母体血清

[0012] Formula 1

[0013] Among them, C PFAS-脐带血清and C PFAS-母体血清 are the concentrations of PFAS target analytes in umbilical cord serum and maternal serum, respectively;

[0014] Estimate the modified TTE (tem) according to Equation 2 and Equation 3:

[0015] C PFAS-母体血 ×V 母体血 ×TTE m =C PFAS-脐带血 ×V 脐带血 Formula 2

[0016] C PFAS-血清 / R=C PFAS-全血

[0017] Formula 3

[0018] Among them, C PFAS-母体血 and C PFAS-脐带血 are the concentrations of PFAS in umbilical cord blood and maternal blood, V 母体血 and V 脐带血 are the volumes of maternal blood and cord blood, respectively;

[0019] C PFAS-血清 is the PFAS concentration in the mixed serum of umbilical cord serum and maternal serum, C PFAS-全血 is the PFAS concentration in the mixed whole blood of umbilical cord serum and maternal serum, and R represents the conversion rate;

[0020] S3: Statistical analysis:

[0021] Statistical analysis was performed using SPSS 23.0, and the mean value was calculated by taking LOD / √2 instead of the concentration below LOD; LOD indicates the limit of detection;

[0022] Spearman correlation analysis was used to explore the correlation between mother and fetus;

[0023] The Mann-Whitney test was used to determine the difference in TTE between infants who were appropriate for gestational age (AGA) and those who were small for gestational age (SGA).

[0024] A second aspect of the present invention provides an evaluation system based on the placental transport efficiency of PFAS chemicals, the system comprising a computing system, the computing system further comprising a hardware processor and a memory coupled to the hardware processor, the hardware processor executing a plurality of modules stored in the memory, wherein the plurality of modules comprises a computing module for performing the calculation steps S2-S3 of the placental transport efficiency of the PFAS chemicals;

[0025] The system further comprises,

[0026] A sample receiver is used to receive samples to be tested, including but not limited to maternal blood collected from fasting blood within 3 days before delivery, umbilical cord blood collected during delivery, or umbilical cord serum and maternal serum samples obtained by further processing the above whole blood samples. However, the above are for illustrative purposes only, and other samples that can be used for testing are also within the scope of protection;

[0027] The detection solution receiver includes an internal standard mixture receiver for receiving the internal standard mixture; an acetonitrile-methanol mixture receiver for receiving the acetonitrile-methanol mixture; and a methanol-water mixture receiver for receiving the acetonitrile-methanol mixture;

[0028] An ultrasonic module, used for dispersing the treated sample, and a sonicator known in the prior art may be used;

[0029] A drying module is used to process the precipitated sample after ultrasound, and uses, but is not limited to, a vacuum drying oven and a rotary evaporator known in the prior art to achieve the above function;

[0030] A liquid adding module is used to switch between different positions of the sample to be tested, the internal standard mixture, the acetonitrile-methanol mixture, the methanol-water mixture, etc., using, but not limited to, an automated liquid adding device or a fully automatic liquid adding workstation known in the prior art to achieve the above functions;

[0031] The detection module includes but is not limited to an ultra-high performance liquid chromatography and / or a triple quadrupole mass spectrometer, which is used to determine the values ​​of PFASs.

[0032] The third aspect of the present invention is to provide an evaluation model based on the placental transport efficiency of PFAS chemicals, which includes the steps of determining and analyzing PFASs in different test samples and the steps of constructing a TTE model.

[0033] The step of determining and analyzing PFASs in different test samples includes the step of determining the placental transport efficiency of the above-mentioned PFAS chemical substances in S1;

[0034] The steps of constructing the TTE model include the calculation steps S2-S3 above.

[0035] Preferably, the volume ratio of the sample to be tested, the internal standard mixed solution, the acetonitrile-methanol mixed solution, and the methanol-water mixed solution is 1:(0.5-1):(2-3):(1-1.5).

[0036] Preferably, the PFAS chemical is selected from one or more of perfluorobutyric acid, perfluoropentanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorotetradecanoic acid, perfluorohexadecanoic acid, perfluorohexadecanoic acid, dodecafluoro-3h-4,8-dioxophosphonate, hexafluoropropylene oxide dimer, 2H-perfluoro-2-decenoic acid, perfluorobutanesulfonic acid, perfluorohexanesulfonic acid, perfluoro-n-heptanesulfonic acid, perfluorooctanesulfonic acid, 6:2 chlorinated polyfluoroethersulfonic acid, perfluorodecanesulfonic acid, 6:2 fluorotelomersulfonic acid, 8:2 fluorotelomersulfonic acid, perfluorooctanesulfonamide, n-methyl perfluorooctanesulfonamide, n-ethyl perfluorooctanesulfonamide, n-methyl perfluorooctanesulfonamide acetate, n-ethyl perfluorooctanesulfonamide acetate, and polyfluoroalkyl phosphate diesters.

[0037] Preferably, the internal standard mixture is an isotope-labeled PFASs standard-methanol solution with a concentration of 10-50 ng / mL.

[0038] Preferably, the isotope-labeled PFASs standard is selected from isotope-labeled perfluorobutyric acid, isotope-labeled perfluoropentanoic acid, isotope-labeled perfluorohexanoic acid, isotope-labeled perfluoroheptanoic acid, isotope-labeled perfluorooctanoic acid, isotope-labeled perfluorononanoic acid, isotope-labeled perfluorodecanoic acid, isotope-labeled perfluoroundecanoic acid, isotope-labeled perfluorododecanoic acid, isotope-labeled perfluorotridecanoic acid, isotope-labeled perfluorotetradecanoic acid, isotope-labeled perfluorohexadecanoic acid, isotope-labeled perfluorohexadecanoic acid, isotope-labeled dodecafluoro-3H-4,8-dioxophosphonate, isotope-labeled hexafluoropropylene oxide dimer, isotope-labeled 2H-perfluoro-2-decenoic acid, , one or more of isotope-labeled perfluorobutane sulfonic acid, isotope-labeled perfluorohexane sulfonic acid, isotope-labeled perfluoro-n-heptane sulfonic acid, isotope-labeled perfluorooctane sulfonic acid, isotope-labeled 6:2 chlorinated polyfluoroether sulfonic acid, isotope-labeled perfluorodecane sulfonic acid, isotope-labeled 6:2 fluorotelomer sulfonic acid, isotope-labeled 8:2 fluorotelomer sulfonic acid, isotope-labeled perfluorooctane sulfonamide, isotope-labeled n-methyl perfluorooctane sulfonamide, isotope-labeled n-ethyl perfluorooctane sulfonamide, isotope-labeled n-methyl perfluorooctane sulfonamide acetate, isotope-labeled n-ethyl perfluorooctane sulfonamide acetate, and isotope-labeled polyfluoroalkyl phosphoric diesters. (Standards purchased from Wellington Laboratories)

[0039] Preferably, the Mann-Whitney test is used to determine the difference in TTE between infants appropriate for gestational age (AGA) and infants small for gestational age (SGA), and the difference is considered significant when P < 0.05.

[0040] Preferably, the method for collecting the different samples to be tested is: collecting fasting blood as maternal blood within 3 days before delivery, collecting umbilical cord blood during delivery, or further processing the above whole blood sample to separate umbilical cord serum and maternal serum samples, and storing them at -80°C for analysis.

[0041] Beneficial effects of the present invention:

[0042] The present invention provides methods, systems, and models for assessing the transplacental transport efficiency of PFAS chemicals. PFAS chemicals are biotransported through the placenta in multiple ways, challenging the existing assumption that a simple ratio-based TTEO is a one-size-fits-all model for assessing transfer efficiency. The present invention's research found no significant differences in PFAS concentrations in maternal serum and umbilical cord serum, as well as in the traditional TTEO, between the AGA and SGA groups.

[0043] However, by using an improved TEM model that considers total PFAS exposure, the present invention successfully determined the difference in TTE between SGA infants and matched healthy controls. TEM results showed that SGA infants were significantly lower than AGA infants. The Mann-Whitney test was used to determine the difference in TTE between infants who were AGA for gestational age and those who were small for gestational age (SGA), and the difference was significant when p < 0.05.

[0044] Compared with traditional TTE, the improved TEM model has certain advantages in active transport and facilitated diffusion, and provides a theoretical basis for further exploring the relationship between PFASs exposure and adverse birth outcomes. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Flow chart of the method for evaluating the placental transport efficiency of PFAS chemicals of the present invention. DETAILED DESCRIPTION

[0046] The present invention is further described in detail below with reference to the embodiments so that those skilled in the art can implement the invention with reference to the description.

[0047] Example 1 Material Preparation

[0048] 30 PFAS chemicals were prepared for testing: including perfluorobutyric acid (PFBA), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorotridecanoic acid (PFTrDA), perfluorotetradecanoic acid (PFTeDA), perfluorohexadecanoic acid (PFHxDA), perfluorohexadecanoic acid (PFODA), dodecafluoro-3h-4,8-dioxophosphonate (ADONA), hexafluoropropylene oxide dimer (HFPO-DA), 2H-perfluoro-2-decenoic acid (FOUEA), perfluorobutanesulfonic acid (PFBSA), and 1,2-difluoro-2-decenoic acid (FOUEA). The following substances were used as raw materials: FBS), perfluorohexanesulfonic acid (PFHxS), perfluoro-n-heptanesulfonic acid (PFHpS), perfluorooctanesulfonic acid (PFOS), 6:2 chlorinated polyfluoroethersulfonic acid (6:2Cl-PFESA), perfluorodecanesulfonic acid (PFDS), 6:2 fluorotelomersulfonic acid (6:2FTS), 8:2 fluorotelomersulfonic acid (8:2FTS), perfluorooctanesulfonamides (FOSAs), n-methylperfluorooctanesulfonamide (N-MeFOSA), n-ethylperfluorooctanesulfonamide (N-EtFOSA), n-methylperfluorooctanesulfonamidoacetate (N-MeFOSAA), n-ethylperfluorooctanesulfonamidoacetate (N-EtFOSAA), and 8:2 polyfluoroalkylphosphodiester (8:2diPAP).

[0049] Analytical reagents: Isotope-labeled PFAS standards corresponding to the 30 PFAS chemicals to be determined were purchased from Wellington Laboratories (Guelph, Ontario, Canada). Water and organic solvents used for analysis were HPLC grade, ≥99.9% pure, and from Fischer Scientific (Hanover Park, IL).

[0050] Example 2 Preparation of research samples

[0051] Study Sample: Volunteers in this example were selected from the "Improving Maternal and Infant Health through Multi-site Exposure Monitoring (TIMFEM)" birth cohort conducted in Hefei, China from December 2021 to September 2022. The study was approved by the Ethics Committee of the Second Affiliated Hospital of Anhui Medical University, China (YX2021-091F1), and the study protocol was conducted in accordance with the principles of the Declaration of Helsinki, as revised in 2008. The researchers explained the nature of the study to all volunteers, and they signed a consent form before enrollment.

[0052] A total of 210 mother-infant pairs were selected. Maternal fasting blood was collected within 3 days before delivery, and umbilical cord blood was collected at delivery. Umbilical cord serum and maternal serum samples were separated and stored at -80°C until analysis. Seventy infants were born small for gestational age (SGA), and 140 were matched controls born appropriate for gestational age (AGA). SGA and AGA infants were individually matched for maternal age and infant sex in a 1:2 ratio.

[0053] The demographic characteristics of the study sample population are shown in Table 1.

[0054] Table 1 Demographic characteristics of the study population

[0055]

[0056] Example 3 Determination and model construction of PFASs in test samples

[0057] Determination of PFASs content in umbilical cord serum: 25 μL of a 20 ng / mL isotope-labeled PFASs standard-methanol solution (internal standard mixture) was added to 50 μL of umbilical cord serum, and then ultrasonically extracted with 150 μL of an acetonitrile-methanol mixture (V / V = 1 / 1). The mixture was precipitated at -20°C for 2 h, the supernatant was discarded and dried, and the resulting precipitate was added to 50 μL of a methanol-water mixture (V / V = 1 / 1). After stirring and dispersion, the precipitate was concentrated and PFASs were determined using an ultra-performance liquid chromatography and a triple quadrupole mass spectrometer.

[0058] The PFASs content in maternal serum, umbilical cord blood, and maternal blood was determined using the same method.

[0059] TTE estimation:

[0060] Calculate TTE0 according to Formula 1:

[0061] TTE0=C PFAS-脐带血清 / C PFAS-母体血清

[0062] Formula 1

[0063] Among them, C PFAS-脐带血清 and C PFAS-母体血清 are the concentrations of PFAS target analytes in umbilical cord serum and maternal serum, respectively;

[0064] Estimate the modified TTE (tem) according to Equation 2 and Equation 3:

[0065] C PFAS-母体血 ×V 母体血 ×TTE m =C PFAS-脐带血 ×V 脐带血 Formula 2

[0066] C PFAS-血清 / R=C PFAS-全血

[0067] Formula 3

[0068] Among them, C PFAS-母体血 and C PFAS-脐带血 are the concentrations of PFAS in umbilical cord blood and maternal blood, V 母体血 and V 脐带血 are the volumes of maternal blood and cord blood, respectively;

[0069] C PFAS-血清 is the PFAS concentration in the mixed serum of umbilical cord serum and maternal serum, C PFAS-全血 is the PFAS concentration in the mixed whole blood of umbilical cord serum and maternal serum, and R represents the conversion rate;

[0070] S3: Statistical analysis:

[0071] Statistical analysis was performed using SPSS 23.0, and the mean value was calculated by taking LOD / √2 instead of the concentration below LOD; LOD indicates the limit of detection;

[0072] Spearman correlation analysis was used to explore the correlation between mother and fetus;

[0073] The Mann-Whitney test was used to determine the difference in TTE between appropriate for gestational age infants (AGA) and small for gestational age infants (SGA). When P < 0.05, the difference was significant.

[0074] In addition, Example 3 further constructs a model system based on a method for evaluating the placental transport efficiency of PFAS chemicals, the system comprising a computing system, the computing system further comprising a hardware processor and a memory coupled to the hardware processor, the hardware processor executing a plurality of modules stored in the memory, wherein the plurality of modules comprises a computing module for performing the calculation steps S2-S3 of the placental transport efficiency of the above-mentioned PFAS chemicals;

[0075] The sample receiver is used to receive maternal blood collected from the mother on fasting within 3 days before delivery, umbilical cord blood collected during delivery, and umbilical cord serum and maternal serum samples separated by further processing of the above whole blood samples;

[0076] The detection solution receiver includes an internal standard mixture receiver for receiving the internal standard mixture; an acetonitrile-methanol mixture receiver for receiving the acetonitrile-methanol mixture; and a methanol-water mixture receiver for receiving the acetonitrile-methanol mixture;

[0077] An ultrasonic module is used to disperse the processed samples, and an ultrasonic instrument can be used;

[0078] Drying module, used to process the precipitated sample after ultrasound. In this embodiment, a vacuum drying oven and a rotary evaporator are used to achieve the above function;

[0079] The liquid adding module is used to switch the positions of the sample to be tested, the internal standard mixture, the acetonitrile-methanol mixture, the methanol-water mixture, etc. This embodiment uses a pipette gun, an automatic liquid adding device, and a fully automatic liquid adding workstation to achieve the above functions;

[0080] The detection module uses ultra-high performance liquid chromatography and / or triple quadrupole mass spectrometry to determine the values ​​of PFASs.

[0081] Example 4 test results

[0082] Prenatal exposure to PFASs at SGA and AGA births

[0083] Of the 30 targeted PFAS chemicals, perfluoroalkyl carboxylic acids (PFCAs) (excluding perfluorohexadecanoic acid (PFODA)) were detected most frequently (35-100% in AGA and 36-100% in SGA), followed by perfluoroalkyl sulfonic acids (PFSAs) (11-100% in AGA and 11-100% in SGA), and precursor chemicals (2-30% in AGA and 1-33% in SGA). Specifically, PFBA, PFHxA, PFOA, PFNA, PFDA, PFUnDA, PFHxS, PFOS, and 6:2Cl-PFESA were detected in 80% of maternal and umbilical cord serum samples. Overall, PFOA and PFOS dominated the other PFASs in all samples, with median concentrations ranging from 1.62-3.94 ng / mL in AGA serum and 1.60-4.80 ng / mL in SGA serum. Current PFAS levels are broadly similar to or within the same range as those reported in human serum, indicating their persistence after use restrictions. The emerging PFAS, 6:2Cl-PFESA (the main component of F-53B, an important alternative to PFOS), was the third most abundant PFAS detected in both AGA and SGA, indicating an urgent need for monitoring and risk assessment given its high market value and frequent detection in China.

[0084] Table 2 Correlation between major PFAS congeners in maternal and umbilical cord serum in SGA

[0085]

[0086] Table 3 Correlation between major PFAS congeners in maternal and umbilical cord serum in AGA

[0087]

[0088]

[0089] Combining Tables 2 and 3, it can be seen that the concentrations of ∑PFASs and most individual PFASs in maternal serum did not differ significantly between AGA and SGA births (p-values ​​> 0.05); similarly, there were no significant differences in individual PFAS chemicals and ∑PFASs in umbilical cord serum between the two groups (p-values ​​> 0.05). The composition of PFASs between AGA and SGA was also similar, regardless of whether umbilical cord serum or maternal serum was used. This indicates that although PFASs exposure does lead to fetal growth restriction in animals, the factors leading to SGA in humans may be very complex. In addition, positive and significant correlations were observed between maternal serum and umbilical cord serum for the main PFAS compounds, with 6:2Cl-PFESA showing the highest correlation coefficient (r = 0.90; AGA was 0.001; R = 0.89; SGA was 0.001), which may be transferred to the fetus through the placenta.

[0090] Comparison of traditional TTE0 and improved TTE0

[0091] For conventional TTE0, the median TTE0 of most investigated PFASs was less than 100%, while the median TTE0 of PFHxA and PFHpA was 324% and 117% in AGA and 250% and 116% in SGA, respectively. The TTE0 of PFASs showed an overall U-shaped trend, with TTE0 decreasing with increasing carbon chain length before a 10-carbon chain (PFDA) and then increasing with increasing carbon number. This is consistent with the pattern previously reported in birth cohorts29,36 and can be explained by their physicochemical properties and corresponding binding affinity to human serum albumin37. PFASs, on the other hand, had lower TTE0s than PFASs of the same carbon chain length.

[0092] By incorporating biological parameters, the inventors estimated the revised TTEm value based on the total PFAS content in whole blood from mother to fetus (Formulas 2 and 3). The calculated results of traditional TTE0 and revised TTEm are shown in Table 4:

[0093] Table 4 Results of traditional TTE0 and modified TTEm

[0094]

[0095]

[0096]

[0097] As shown in Table 4, TTEm values ​​were all less than 100%, with median TTEm values ​​ranging from 2.3% (PFDA and PFOS) to 21.1% (PFHxA) in AGA and from 1.6% (PFOS) to 11.3% (PFHxA) in SGA. Similar to traditional TTE0s, TTEm values ​​for PFASs also exhibited a U-shaped pattern. Due to differences in estimation methods, TTEm values ​​were significantly lower than the corresponding traditional TTE0s (approximately an order of magnitude lower). Compared with traditional TTE0s, the TTEm values ​​for short-chain PFASs (e.g., PFHxA) and long-chain PFASs (e.g., PFTrDA) decreased the most, and the underlying mechanisms warrant further investigation.

[0098] In fact, traditional TTE0 can be used to measure placental transport capacity, assuming that most PFASs pass through the placental barrier by passive transport, because passive transport is mainly driven by the concentration gradient between the two sides of the placenta (maternal and fetal). However, the inventors found that active transport or facilitated diffusion of PFASs may be important and may be more important than passive transport because these chemicals have hydrophobic and lipophobic properties and require transport proteins to enter cells. Therefore, compared with traditional TTE0, the inventors found that the improved TTEm model is more conducive to reflecting the transplacental transfer efficiency of chemicals, especially when the transport mechanism is caused by multiple factors.

[0099] Modified TTEm was significantly lower in SGA than in AGA: To understand the difference in TTE between AGA and SGA, i.e., nutrient transfer efficiency was also affected, we recruited matched AGA and SGA participants in a 2:1 ratio. No significant differences were found in the traditional TTE0s of PFASs (except PFPeA, p = 0.04) between AGA and SGA births, although most TTE0s were slightly lower in SGA than in AGA. In contrast, the modified TTEms of most PFASs were significantly lower (p value < 0.05). To the best of the inventors' knowledge, the difference in PFAS TTEs between appropriate weight or SGA has not been comprehensively studied before. However, existing data observed a positive correlation between birth weight and TTE 39, which supports our findings in SGA patients.

[0100] As mentioned above, TEMs may have certain advantages when multiple transport modes other than passive diffusion are involved. In a Chinese birth cohort study, researchers observed a significant association between the expression of mRNAs encoding active transport proteins and the TTEs of selected PFASs (including PFNA, PFDA, PFUnDA, PFDoDA, PFTrDA, and PFOS). Kummu et al. also found that the organic anion transporter 4 (OAT4) transporter was associated with the placental transfer of PFOA and PFOS. Notably, for these PFASs chemicals involved in active transport, the difference in TTEs between AGA and SGA was highly significant (p value < 0.001). This further suggests that the two TTE estimates are associated with different transport modes. Since TTEs were significantly decreased in the SGA group, the inventors speculate that the active transport capacity of the SGA group for placental transfer is impaired. Previous studies have suggested that PFASs may have adverse effects on placental development and function. Therefore, this may lead to limited active transport of nutrients, growth factors, hormones, etc., ultimately leading to SGA. It can be seen that the establishment of this model can effectively simulate and evaluate the transport efficiency of PFAS chemicals and further determine the correlation with postnatal parameters of infants.

[0101] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to specific details.

Claims

1. A method for evaluating the placental transport efficiency of PFAS chemicals, characterized in that: The following steps are involved: S1: Detect and analyze PFASs in different blood samples; S2: TTE estimation: Calculate TTE0 according to Formula 1: Formula 1 in, and are the concentrations of PFAS target analytes in umbilical cord serum and maternal serum, respectively; Estimated corrected TTEm according to Equation 2 and Equation 3: Formula 2 Formula 3 in, and are the concentrations of PFAS in umbilical cord blood and maternal blood, and are the volumes of maternal blood and cord blood, respectively; is the PFAS concentration in the mixed serum of umbilical cord serum and maternal serum, is the PFAS concentration in the mixed whole blood of umbilical cord serum and maternal serum, and R represents the conversion rate; S3: Statistical analysis: Statistical analysis was performed using SPSS 23.0, and the mean value was calculated by taking LOD / √2 instead of the concentration below LOD; LOD indicates the limit of detection; Spearman correlation analysis was used to explore the correlation between mother and fetus; The Mann-Whitney test was used to determine the difference in TTE between infants who were appropriate for gestational age (AGA) and those who were small for gestational age (SGA).

2. A system for evaluating the placental transport efficiency of PFAS chemicals, the system comprising a computing system, the computing system further comprising a hardware processor, a memory coupled to the hardware processor, the hardware processor executing a plurality of modules stored in the memory, wherein the plurality of modules comprises a computing module for performing steps S2-S3 of calculating the placental transport efficiency of PFAS chemicals according to claim 1; The system further comprises, A sample receiver, used for receiving a sample to be tested; A detection solution receiver, used to receive the detection solution required by the detection system; Ultrasonic module, used to disperse the processed samples; Drying module, used to process the precipitated sample after ultrasonication; The liquid adding module is used to switch the positions of the sample to be tested, the internal standard mixture, the acetonitrile-methanol mixture, and the methanol-water mixture; Detection module, used to determine the value of PFASs.

3. The evaluation system according to claim 2, wherein the sample receiver is used to receive maternal blood, umbilical cord blood or umbilical cord serum and maternal serum samples separated by further processing; the solution receiver includes an internal standard mixture receiver for receiving an internal standard mixture; an acetonitrile-methanol mixture receiver for receiving an acetonitrile-methanol mixture; a methanol-water mixture receiver for receiving an acetonitrile-methanol mixture; an ultrasonic module includes an ultrasonic instrument; a drying module includes a vacuum drying oven and a rotary evaporator; a liquid adding module is used to switch the sample to be tested, the internal standard mixture, the acetonitrile-methanol mixture, and the methanol-water mixture to different positions; the detection module includes but is not limited to an ultra-high performance liquid chromatograph and / or a triple quadrupole mass spectrometer.

4. The method for evaluating the placental transport efficiency of PFAS chemicals according to claim 1, wherein: The method for detecting PFASs in the blood sample to be tested in step S1 is as follows: adding an internal standard mixed solution to different samples to be tested respectively, then ultrasonically extracting with an acetonitrile-methanol mixture, precipitating at -20°C for 2 hours, discarding the supernatant and drying, and then adding the obtained precipitate to a methanol-water mixture, stirring and dispersing, concentrating and using an ultra-high performance liquid chromatography and a triple quadrupole mass spectrometer to determine PFASs; the different samples to be tested include umbilical cord serum, maternal serum, umbilical cord blood, and maternal blood.

5. The evaluation system according to claim 2-3, characterized in that: The volume ratio of the sample to be tested, the internal standard mixed solution, the acetonitrile-methanol mixed solution, and the methanol-water mixed solution is 1:(0.5-1):(2-3):(1-1.5).

6. The method for evaluating the placental transport efficiency of PFAS chemicals according to claim 1 or the evaluation system according to claims 2-3, characterized in that: The PFAS chemical substances are selected from one or more of perfluorobutyric acid, perfluoropentanoic acid, perfluorohexanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid, perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, perfluorotridecanoic acid, perfluorotetradecanoic acid, perfluorohexadecanoic acid, perfluorohexadecanoic acid, dodecafluoro-3h-4,8-dioxophosphonate, hexafluoropropylene oxide dimer, 2H-perfluoro-2-decenoic acid, perfluorobutane sulfonic acid, perfluorohexane sulfonic acid, perfluoro-n-heptane sulfonic acid, perfluorooctane sulfonic acid, 6:2 chlorinated polyfluoroether sulfonic acid, perfluorodecane sulfonic acid, 6:2 fluorotelomer sulfonic acid, 8:2 fluorotelomer sulfonic acid, perfluorooctane sulfonamide, n-methyl perfluorooctane sulfonamide, n-ethyl perfluorooctane sulfonamide, n-methyl perfluorooctane sulfonamide acetate, n-ethyl perfluorooctane sulfonamide acetate, and polyfluoroalkyl phosphoric acid diesters.

7. The evaluation system according to claim 2-3, characterized in that: The internal standard mixture is an isotope-labeled PFASs standard-methanol solution with a concentration of 10-50 ng / mL.

8. The evaluation system according to claim 7, wherein: The isotope-labeled PFASs standard is selected from isotope-labeled perfluorobutyric acid, isotope-labeled perfluoropentanoic acid, isotope-labeled perfluorohexanoic acid, isotope-labeled perfluoroheptanoic acid, isotope-labeled perfluorooctanoic acid, isotope-labeled perfluorononanoic acid, isotope-labeled perfluorodecanoic acid, isotope-labeled perfluoroundecanoic acid, isotope-labeled perfluorododecanoic acid, isotope-labeled perfluorotridecanoic acid, isotope-labeled perfluorotetradecanoic acid, isotope-labeled perfluorohexadecanoic acid, isotope-labeled perfluorohexadecanoic acid, isotope-labeled dodecafluoro-3h One or more of: -4,8-dioxophosphonate, isotope-labeled hexafluoropropylene oxide dimer, isotope-labeled 2H-perfluoro-2-decenoic acid, isotope-labeled perfluorobutane sulfonic acid, isotope-labeled perfluorohexane sulfonic acid, isotope-labeled perfluoro-n-heptane sulfonic acid, isotope-labeled perfluorooctane sulfonic acid, isotope-labeled 6:2 chlorinated polyfluoroether sulfonic acid, isotope-labeled perfluorodecane sulfonic acid, isotope-labeled 6:2 fluorotelomer sulfonic acid, isotope-labeled 8:2 fluorotelomer sulfonic acid, isotope-labeled perfluorooctane sulfonamide, isotope-labeled n-methyl perfluorooctane sulfonamide, isotope-labeled n-ethyl perfluorooctane sulfonamide, isotope-labeled n-methyl perfluorooctane sulfonamide acetate, isotope-labeled n-ethyl perfluorooctane sulfonamide acetate, and isotope-labeled polyfluoroalkyl phosphoric diesters.

9. The method for evaluating the placental transport efficiency of PFAS chemicals according to claim 1 or the evaluation system according to claims 2-3, characterized in that: The method for collecting the sample to be tested is: collecting fasting blood as maternal blood within 3 days before delivery, and collecting umbilical cord blood during delivery; or further collecting maternal blood and umbilical cord blood and separating umbilical cord serum and maternal serum samples respectively, and storing them at -80°C for analysis.

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