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1.
Bioessays ; : e2400072, 2024 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-38922935

RESUMEN

This year marks the tenth anniversary of the world's first transplantation of tissue generated from induced pluripotent stem cells (iPSCs). There is now a growing number of clinical trials worldwide examining the efficacy and safety of autologous and allogeneic iPSC-derived products for treating various pathologic conditions. As we patiently wait for the results from these and future clinical trials, it is imperative to strategize for the next generation of iPSC-based therapies. This review examines the lessons learned from the development of another advanced cell therapy, chimeric antigen receptor (CAR) T cells, and the possibility of incorporating various new bioengineering technologies in development, from RNA engineering to tissue fabrication, to apply iPSCs not only as a means to achieve personalized medicine but also as designer medical applications.

2.
Nanomaterials (Basel) ; 14(12)2024 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-38921918

RESUMEN

The enhancement of carbon-supported components is a crucial factor in augmenting the interplay between carbon-supported and metal-active components in the utilization of catalysts for direct ethanol fuel cells (DEFCs). Here, we propose a strategy for designing a catalyst by modifying candle soot (CS) and loading nickel onto ordered carbon soot. The present study aimed to investigate the effect of the Ni nanoparticles content on the electrocatalytic performance of Ni-CS, ultimately leading to the identification of a maximum composition. The presence of an excessive quantity of nickel particles leads to a decrease in the number of active sites within the material, resulting in sluggishness of the electron transfer pathway. The electrocatalyst composed of nickel and carbon support, with a nickel content of 20 wt%, has demonstrated a noteworthy current activity of 18.43 mA/cm2, which is three times that of the electrocatalyst with a higher nickel content of 25 wt%. For example, the 20 wt% Ni-CS electrocatalytic activity was found to be good, and it was approximately four times higher than that of 20 wt% Ni-CB (nickel-carbon black). Moreover, the chronoamperometry (CA) test demonstrated a reduction in current activity of merely 65.80% for a 20 wt% Ni-CS electrocatalyst, indicating electrochemical stability. In addition, this demonstrates the great potential of candle soot with Ni nanoparticles to be used as a catalyst in practical applications.

3.
Cell ; 187(13): 3229-3230, 2024 Jun 20.
Artículo en Inglés | MEDLINE | ID: mdl-38906098

RESUMEN

Dr. Shinya Yamanaka is recognized for his discovery of the induction of pluripotent stem cells from fibroblasts by a combination of defined factors. In this interview with Cell, he discusses the progress of the field, what's next for clinical applications of iPS cells, and the state of science in Japan and the rest of the world.


Asunto(s)
Células Madre Pluripotentes Inducidas , Animales , Humanos , Fibroblastos/citología , Fibroblastos/metabolismo , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Japón , Tratamiento Basado en Trasplante de Células y Tejidos , Separación Celular , Técnicas de Cultivo de Célula , Medicina Comunitaria
4.
Stem Cell Reports ; 19(5): 710-728, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38701780

RESUMEN

Heterogeneity among both primed and naive pluripotent stem cell lines remains a major unresolved problem. Here we show that expressing the maternal-specific linker histone H1FOO fused to a destabilizing domain (H1FOO-DD), together with OCT4, SOX2, KLF4, and LMYC, in human somatic cells improves the quality of reprogramming to both primed and naive pluripotency. H1FOO-DD expression was associated with altered chromatin accessibility around pluripotency genes and with suppression of the innate immune response. Notably, H1FOO-DD generates naive induced pluripotent stem cells with lower variation in transcriptome and methylome among clones and a more uniform and superior differentiation potency. Furthermore, we elucidated that upregulation of FKBP1A, driven by these five factors, plays a key role in H1FOO-DD-mediated reprogramming.


Asunto(s)
Reprogramación Celular , Histonas , Células Madre Pluripotentes Inducidas , Factor 4 Similar a Kruppel , Reprogramación Celular/genética , Humanos , Células Madre Pluripotentes Inducidas/citología , Células Madre Pluripotentes Inducidas/metabolismo , Histonas/metabolismo , Diferenciación Celular/genética , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción de Tipo Kruppel/genética , Factores de Transcripción SOXB1/metabolismo , Factores de Transcripción SOXB1/genética , Cromatina/metabolismo , Células Madre Pluripotentes/metabolismo , Células Madre Pluripotentes/citología , Factores de Transcripción/metabolismo , Factores de Transcripción/genética , Transcriptoma
5.
Intern Med ; 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38599863

RESUMEN

A 34-year-old transgender woman presented with ventricular tachycardia and was diagnosed with takotsubo cardiomyopathy. Further evaluation revealed an underlying diagnosis of multiple sclerosis (MS) with brainstem lesions that may have triggered takotsubo cardiomyopathy. In this report, we also systematically reviewed published cases of takotsubo cardiomyopathy and MS and found that basal type takotsubo cardiomyopathy was the most common, and most patients presented with brainstem involvement of MS. An awareness of these associations by physicians, along with multidisciplinary collaboration, may facilitate the early diagnosis and improve the prognosis of these patients.

6.
Respirol Case Rep ; 12(3): e01331, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38528945

RESUMEN

Refractory pneumothorax associated with interstitial lung disease (ILD) remains a challenging condition due to the patient's tolerability and lung compliance that restrict the feasibility of aggressive interventions. Additionally, many cases recur after improvement with treatment, and reports of successful management for this complicated condition are limited. Herein, we report the case of a 60-year-old man with ILD, utilizing home oxygen therapy, who experienced a successful recovery from a surgical intervention under local anaesthesia for pneumothorax. This case highlights the potential for operative intervention under local anaesthesia as a viable option for patients who do not respond to internal approaches.

7.
Inflamm Regen ; 43(1): 43, 2023 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-37684663

RESUMEN

BACKGROUND: Disease-specific induced pluripotent stem cells (iPSCs) are useful tools for pathological analysis and diagnosis of rare diseases. Given the limited available resources, banking such disease-derived iPSCs and promoting their widespread use would be a promising approach for untangling the mysteries of rare diseases. Herein, we comprehensively established iPSCs from patients with designated intractable diseases in Japan and evaluated their properties to enrich rare disease iPSC resources. METHODS: Patients with designated intractable diseases were recruited for the study and blood samples were collected after written informed consent was obtained from the patients or their guardians. From the obtained samples, iPSCs were established using the episomal method. The established iPSCs were deposited in a cell bank. RESULTS: We established 1,532 iPSC clones from 259 patients with 139 designated intractable diseases. The efficiency of iPSC establishment did not vary based on age and sex. Most iPSC clones originated from non-T and non-B hematopoietic cells. All iPSC clones expressed key transcription factors, OCT3/4 (range 0.27-1.51; mean 0.79) and NANOG (range 0.15-3.03; mean 1.00), relative to the reference 201B7 iPSC clone. CONCLUSIONS: These newly established iPSCs are readily available to the researchers and can prove to be a useful resource for research on rare intractable diseases.

9.
Mol Pharm ; 20(8): 4071-4085, 2023 08 07.
Artículo en Inglés | MEDLINE | ID: mdl-37498232

RESUMEN

Coamorphous formulation is a useful approach for enhancing the solubility of poorly water-soluble drugs via intermolecular interactions. In this study, a hydrogen-bonding-based coamorphous system was developed to improve drug solubility, but it barely changed the apparent permeability (Papp) of the drug. This study aimed to design a novel coamorphous salt using ionic interactions to improve drug permeability and absorption. Telmisartan (TMS), with an acidic group, was used to form a coamorphous salt with basic amlodipine (AML). Evaluation of the physicochemical properties confirmed the formation of a coamorphous salt via ionic interactions between the amine group of AML and the carboxyl group of TMS at a molar ratio of 1:1. The coamorphous salt of TMS/AML enhanced the partitioning of both drugs into octanol, indicating increased lipophilicity owing to the interaction between TMS and AML. The coamorphous salt dramatically enhanced TMS solubility (99.8 times that of untreated TMS) and decreased AML solubility owing to the interaction between TMS and AML. Although the coamorphous salt showed a decreased Papp in the permeation study in the presence of a thicker unstirred water layer (UWL) without stirring, Papp increased in the presence of a thinner UWL with stirring. The oral absorption of TMS from the coamorphous salt increased by up to 4.1 times compared to that of untreated TMS, whereas that of AML remained unchanged. Although the coamorphous salt with increased lipophilicity has a disadvantage in terms of diffusion through the UWL, the UWL is thin in human/animal bodies owing to the peristaltic action of the digestive tract. Dissociation of the coamorphous salt on the membrane surface could contribute to the partitioning of the neutral form of drugs to the membrane cells compared with untreated drugs. As a result, coamorphous salt formation has the advantage of improving the membrane permeation and oral absorption of TMS, owing to the enhanced solubility and supply of membrane-permeable free TMS on the surface of the membrane.


Asunto(s)
Amlodipino , Leucemia Mieloide Aguda , Animales , Humanos , Telmisartán , Solubilidad , Permeabilidad , Agua
10.
Dev Cell ; 58(16): 1477-1488.e5, 2023 08 21.
Artículo en Inglés | MEDLINE | ID: mdl-37354899

RESUMEN

Biological patterning events that occur early in development establish proper tissue morphogenesis. Identifying the mechanisms that guide these patterning events is necessary in order to understand the molecular drivers of development and disease and to build tissues in vitro. In this study, we use an in vitro model of gastrulation to study the role of tight junctions and apical/basolateral polarity in modulating bone morphogenic protein-4 (BMP4) signaling and gastrulation-associated patterning in colonies of human pluripotent stem cells (hPSCs). Disrupting tight junctions via knockdown (KD) of the scaffolding tight junction protein-1 (TJP1, also known as ZO1) allows BMP4 to robustly and ubiquitously activate pSMAD1/5 signaling over time, resulting in loss of the patterning phenotype and marked differentiation bias of pluripotent stem cells to primordial germ cell-like cells (PGCLCs). These findings give important insights into how signaling events are regulated and lead to spatial emergence of diverse cell types in vitro.


Asunto(s)
Gastrulación , Células Madre Pluripotentes , Humanos , Linaje de la Célula , Gastrulación/fisiología , Diferenciación Celular , Células Germinativas , Proteína de la Zonula Occludens-1/genética , Proteína de la Zonula Occludens-1/metabolismo
11.
Chem Pharm Bull (Tokyo) ; 71(3): 257-261, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36858532

RESUMEN

The importance of permeability as well as solubility of the drug has been recognized in improving the solubility of poorly water-soluble drugs. This study investigated the impact of amorphous composites of indomethacin (IMC) and sulindac (SLD) on the membrane permeability of drugs. The IMC/SLD (1/1) formulation prepared by dry grinding was amorphous with a single glass transition temperature. The Fourier transform IR spectra and Raman spectra revealed formation of hydrogen bonds between the OH group of IMC and the carbonyl group of SLD. These results suggest that an amorphous composite was formed between IMC and SLD through hydrogen bonding. The amount of dissolved IMC and SLD from the amorphous composite of IMC/SLD (1/1) was higher than that of the untreated IMC or SLD in the dissolution test. The permeated amounts and permeation rates of both drugs were enhanced by increasing the solubility of the amorphous composite. Conversely, the apparent membrane permeability coefficients (Papp) were almost same for untreated drugs and amorphous composites. In the case of hydroxypropyl-ß-cyclodextrin and sodium dodecyl sulfate, Papp of the drugs decreased with the addition of these compounds, although the drug solubility was enhanced by the solubilization effect. This study revealed that an amorphous composite formed through hydrogen bonding is an attractive pharmaceutical way to enhance the permeated amount and permeation rate without changing the Papp of both the drugs.


Asunto(s)
Indometacina , Sulindac , 2-Hidroxipropil-beta-Ciclodextrina/química , Permeabilidad de la Membrana Celular , Permeabilidad , Solubilidad , Dodecil Sulfato de Sodio/química
12.
Foods ; 12(3)2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36766015

RESUMEN

Alzheimer's disease (AD) is thought to be caused by the deposition of amyloid-ß (Aß) in the brain. Aß begins to aggregate approximately 20 years before the expression of its symptoms. Previously, we developed a microliter-scale high-throughput screening (MSHTS) system for inhibitors against Aß aggregation using quantum dot nanoprobes. Using this system, we also found that plants in the Lamiaceae, particularly Perilla frutescens var. crispa, have high activity. The cultivation environment has the potential to enhance Aß aggregation inhibitory activity in plants by changing their metabolism. Here, we report on cultivation factors that affected the activity of P. frutescens var. crispa cultivated in three fields under different cultivation conditions. The results revealed that the activity of P. frutescens var. crispa harvested just before flowering was highest. Interestingly, the activity of wind-shielded plants that were cultivated to prevent exposure to wind, was reduced to 1/5th of plants just before flowering. Furthermore, activity just before flowering increased following appropriate nitrogen fertilization and at least one week of drying from the day before harvest. In addition, we confirmed that the P. frutescens var. crispa leaf extracts suppressed Aß-induced toxicity in nerve growth factor-differentiated PC12 cells. In this study, we demonstrated that flowering, wind, soil water content, and soil nitrogen content affected Aß aggregation inhibitory activity, necessary to suppress Aß neurotoxicity, in P. frutescens var. crispa extracts. This study provides practical cultivation methods for P. frutescens var. crispa with high Aß aggregation inhibitory activity for the prevention of AD.

13.
Med ; 4(1): 51-66.e10, 2023 01 13.
Artículo en Inglés | MEDLINE | ID: mdl-36395757

RESUMEN

BACKGROUND: Human induced pluripotent stem cells (iPSCs) are expected to be useful for regenerative medicine for many diseases. Many researchers have focused on and enabled the generation of differentiated cells or tissue-like structures, including organoids, which help to ameliorate target diseases. To promote such cell therapies, we established a clinically applicable iPSC haplobank matching as many people as possible in Japan. METHODS: Through cooperation with several organizations, we recruited donors whose human leukocyte antigens (HLAs) involved in immunorejection were homozygous. The peripheral or umbilical cord blood collected from the donors was used for iPSC production by electroporation of episomal vectors. These iPSC lines were then subjected to testing, including genome analyses and sterility, to maximize safety. FINDINGS: We constructed a clinical-grade haplobank of 27 iPSC lines from 7 donors according to good manufacturing practice regulations. However, reasons to avoid using iPSC lines include the presence of residual episomal vectors or genetic mutations in cancer-related genes. CONCLUSIONS: This haplobank provides HLA-matched iPSC lines for approximately 40% of the Japanese population. Since the haplobank's release in 2015, these iPSC lines have been used in more than 10 clinical trials. The establishment of this haplobank is an important step toward the clinical application of iPSCs in cell therapies. FUNDING: This study was supported by a research center network for the realization of regenerative medicine of the Japan Agency for Medical Research and Development (AMED) under grant number JP20bm0104001h0108.


Asunto(s)
Células Madre Pluripotentes Inducidas , Humanos , Células Madre Pluripotentes Inducidas/metabolismo , Pueblos del Este de Asia , Homocigoto , Antígenos HLA/genética , Antígenos HLA/metabolismo , Diferenciación Celular
14.
JAMA Netw Open ; 5(12): e2247704, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36574249

RESUMEN

Importance: Real-world evidence of SARS-CoV-2 transmission is needed to understand the prevalence of infection in the Japanese population. Objective: To conduct sentinel screening of the Japanese population to determine the prevalence of SARS-CoV-2 infection in asymptomatic individuals, with complementary analysis for symptomatic patients as reported by active epidemiologic surveillance used by the government. Design, Setting, and Participants: This cross-sectional study of a sentinel screening program investigated approximately 1 million asymptomatic individuals with polymerase chain reaction (PCR) testing for SARS-CoV-2 infection between February 22 and December 8, 2021. Participants included children, students, employed adults, and older individuals, as well as volunteers to broadly reflect the general Japanese population in the 14 prefectures of Japan that declared a state of emergency. Saliva samples and a cycle threshold (Ct) value of approximately 40 as standard in Japan were used. Polymerase chain reaction testing for symptomatic patients was separately done by public health authorities, and the results were obtained from the Ministry of Health, Labour, and Welfare of Japan to complement data on asymptomatic infections from the present study. Main Outcomes and Measures: Temporal trends in positivity and prevalence (including surges of different variants) and demographic associations (eg, age, geographic location, and vaccination status) were assessed. Results: The positive rate of SARS-CoV-2 infection in 1 082 976 asymptomatic individuals (52.08% males; mean [SD] age 39.4 [15.7] years) was 0.03% (95% CI, 0.02%-0.05%) during periods without surges and a maximum of 0.33% (95% CI, 0.25%-0.43%) during peak surges at the Japanese standard Ct value of approximately 40; however, the positive rate would have been 10-fold less at a Ct value of 25 as used elsewhere in the world (eg, UK). There was an increase in patients with a positive PCR test result with a Ct value of 25 or 30 preceding surges in infection and hotspots of asymptomatic infections. Conclusions and Relevance: In this cross-sectional study of asymptomatic SARS-CoV-2 infection in the general population of Japan in 2021, as investigated by sentinel surveillance, a low rate of infection was seen in the Japanese population compared with reported levels elsewhere in the world. This finding provides real-world data on the state of infection in Japan.


Asunto(s)
COVID-19 , Masculino , Adulto , Niño , Humanos , Femenino , COVID-19/diagnóstico , COVID-19/epidemiología , SARS-CoV-2 , Infecciones Asintomáticas/epidemiología , Prevalencia , Japón/epidemiología , Estudios Transversales
15.
Cell Rep Methods ; 2(11): 100317, 2022 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-36447645

RESUMEN

Naive human induced pluripotent stem cells (iPSCs) can be generated by reprogramming somatic cells with Sendai virus (SeV) vectors. However, only dermal fibroblasts have been successfully reprogrammed this way, and the process requires culture on feeder cells. Moreover, SeV vectors are highly persistent and inhibit subsequent differentiation of iPSCs. Here, we report a modified SeV vector system to generate transgene-free naive human iPSCs with superior differentiation potential. The modified method can be applied not only to fibroblasts but also to other somatic cell types. SeV vectors disappear quickly at early passages, and this approach enables the generation of naive iPSCs in a feeder-free culture. The naive iPSCs generated by this method show better differentiation to trilineage and extra-embryonic trophectoderm than those derived by conventional methods. This method can expand the application of iPSCs to research on early human development and regenerative medicine.


Asunto(s)
Células Madre Pluripotentes Inducidas , Humanos , Reprogramación Celular/genética , Virus Sendai/genética , Vectores Genéticos , Diferenciación Celular/genética
16.
J Anat ; 241(3): 820-830, 2022 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-35638289

RESUMEN

The subcommissural organ (SCO) is a part of the circumventricular organs located in the dorsocaudal region of the third ventricle at the entrance of the aqueduct of Sylvius. The SCO comprises epithelial cells and produces high molecular weight glycoproteins, which are secreted into the third ventricle and become part of Reissner's fibre in the cerebrospinal fluid. Abnormal development of the SCO has been linked with congenital hydrocephalus, a condition characterized by excessive accumulation of cerebrospinal fluid in the brain. In the present study, we characterized the SCO cells in the adult mouse brain to gain insights into the possible role of this brain region. Immunohistochemical analyses revealed that expression of Pax6, a transcription factor essential for SCO differentiation during embryogenesis, is maintained in the SCO at postnatal stages from P0 to P84. SCO cells in the adult brain expressed known neural stem/progenitor cell (NSPC) markers, Sox2 and vimentin. The adult SCO cells also expressed proliferating marker PCNA, although expression of another proliferation marker Ki67, indicating a G2 /M phase, was not detected. The SCO cells did not incorporate BrdU, a marker for DNA synthesis in the S phase. Therefore, the SCO cells have a potential for proliferation but are quiescent for cell division in the adult. The SCO cells also expressed GFAP, a marker for astrocytes or NSPCs, but not NeuN (for neurons). A few cells positive for Iba1 (microglia), Olig2 (for oligodendrocytes) and PDGFRα (oligodendrocyte progenitors) existed within or on the periphery of the SCO. These findings revealed that the SCO cells have a unique feature as secretory yet immature neuroepithelial cells in the adult mouse brain.


Asunto(s)
Hidrocefalia , Órgano Subcomisural , Animales , Ventrículos Cerebrales/metabolismo , Glicoproteínas/metabolismo , Hidrocefalia/líquido cefalorraquídeo , Hidrocefalia/genética , Ratones , Células Neuroepiteliales
17.
Langmuir ; 38(21): 6741-6751, 2022 05 31.
Artículo en Inglés | MEDLINE | ID: mdl-35579967

RESUMEN

Spray freeze drying (SFD) is an ice templating method used to produce highly porous particles with complex pore architectures governed by ice nucleation and growth. SFD particles have been advanced as drug carrier systems, but the quantitative description of the morphology formation in the SFD process is still challenging. Here, the pore space dimensions of SFD particles prepared from aqueous dextran solutions of varying molecular weights (40-200 kDa) and concentrations (5-20%) are analyzed using scanning electron microscopy. Coexisting morphologies composed of cellular and dendritic motifs are obtained, which are attributed to variations in the ice growth mechanism determined by the SFD system and modulation of these mechanisms by given precursor solution properties leading to changes in their pore dimensions. Particles with low-aspect ratio cellular pores showing variation of around 0.5-1 µm in diameter with precursor composition but roughly constant with particle diameter are ascribed to a rapid growth regime with high nucleation site density. Image analysis suggests that the pore volume decreases with dextran solid content. Dendritic pores (≈2-20 µm in diameter) with often a central cellular region are identified with surface nucleation and growth followed by a slower growth regime, leading to the overall dendrite surface area scaling approximately linearly with the particle diameter. The dendrite lamellar spacing depends on the concentration according to an inverse power law but is not significantly influenced by molecular weight. Particles with highly elongated cellular pores without lamellar formation show intermediate pore dimensions between the above two limiting morphological types. Analysis of variance and post hoc tests indicate that dextran concentration is the most significant factor in affecting the pore dimensions. The SFD dextran particles herein described could find use in pulmonary drug delivery due to their high porosity and biocompatibility of the matrix material.


Asunto(s)
Dextranos , Hielo , Liofilización/métodos , Peso Molecular , Tamaño de la Partícula , Porosidad
18.
iScience ; 25(5): 104289, 2022 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-35573189

RESUMEN

The effects of transcription factors on the maintenance and differentiation of human-induced or embryonic pluripotent stem cells (iPSCs/ESCs) have been well studied. However, the importance of posttranscriptional regulatory mechanisms, which cause the quantitative dissociation of mRNA and protein expression, has not been explored in detail. Here, by combining transcriptome and proteome profiling, we identified 228 posttranscriptionally regulated genes with strict upregulation of the protein level in iPSCs/ESCs. Among them, we found 84 genes were vital for the survival of iPSCs and HDFs, including 20 genes that were specifically necessary for iPSC survival. These 20 proteins were upregulated only in iPSCs/ESCs and not in differentiated cells derived from the three germ layers. Although there are still unknown mechanisms that downregulate protein levels in HDFs, these results reveal that posttranscriptionally regulated genes have a crucial role in iPSC survival.

19.
Cell Rep Methods ; 2(2): 100155, 2022 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-35474962

RESUMEN

Xeno-free culture systems have expanded the clinical and industrial application of human pluripotent stem cells (PSCs). However, reproducibility issues, often arising from variability during passaging steps, remain. Here, we describe an improved method for the subculture of human PSCs. The revised method significantly enhances the viability of human PSCs by lowering DNA damage and apoptosis, resulting in more efficient and reproducible downstream applications such as gene editing and directed differentiation. Furthermore, the method does not alter PSC characteristics after long-term culture and attenuates the growth advantage of abnormal subpopulations. This robust passaging method minimizes experimental error and reduces the rate of PSCs failing quality control of human PSC research and application.


Asunto(s)
Células Madre Pluripotentes , Humanos , Reproducibilidad de los Resultados , Diferenciación Celular/genética
20.
Chemosphere ; 297: 134057, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35227751

RESUMEN

Cadmium is adsorbed on calcium carbonate via chemisorption. All calcium carbonate polymorphs generate otavite (cadmium carbonate), indicating that the crystallographic differences in calcium carbonate should affect the chemisorption equilibrium and kinetics. This study investigates the influences of the polymorph and specific surface area on cadmium adsorption. Here, we synthesise two polymorphs of porous calcium carbonate: calcite and vaterite with a wide range of specific surface areas. Then the equilibrium of cadmium adsorption is evaluated using adsorption isotherm models. Based on the Langmuir model with linear regression analysis, the maximum adsorptions of porous calcite and vaterite particles are 287.8 mg/g and 883.5 mg/g, respectively. The kinetics of cadmium chemisorption show clear differences between polymorphs. The calculated rate constant of the porous calcite particles using a pseudo-second-order reaction and Elovich models are two orders larger than that of porous vaterite particles. Although the adsorbed amount is superior for porous vaterite particles, porous calcite particles exhibit a faster reaction and relatively high adsorbed capacity for cadmium ions.


Asunto(s)
Cadmio , Carbonato de Calcio , Adsorción , Carbonato de Calcio/química , Cinética , Porosidad
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