The intestinal absorption mechanism of domoic acid (DA) was investigated using Caco-2 cells. DA is a tricarboxylic amino acid that contains a glutamic acid moiety, and causes deficits in short-term memory by binding to glutamate receptors as an agonist of glutamic acid. Caco-2 cell monolayers cultured on permeable membranes were incubated with 100 μM DA on either the apical or basolateral side, and the transcellular transport of DA was measured. The transcellular transport of DA from the apical to basolateral side was about twofold that in the opposite direction. The transcellular transport of DA from the apical side was optimal at a neutral pH, and was temperature- and Cl(-)-dependent, but was Na(+)-independent. Coincubation of DA with 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS), an anion exchange inhibitor, significantly decreased the apical-to-basolateral transport of DA by 48%, and coincubation with probenecid (a non-specific anion transport inhibitor) significantly decreased the transport of DA by 31%. In contrast, coincubation with glutamic acid, succinic acid (a dicarboxylic acid), or citric acid (a tricarboxylic acid) did not decrease the transport of DA. These results suggest that the apical-to-basolateral transport of DA across the Caco-2 cell monolayers is mediated by DIDS-sensitive anion transporters.
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http://dx.doi.org/10.1016/j.fct.2011.06.001 | DOI Listing |
Biomed Mater
January 2025
Department of Orthopedics, Zhongshan Hospital Fudan University, No. 180, Xietu Road, Shanghai, Shanghai, 200032, CHINA.
Nanoparticles (NPs) have been explored as drugs carriers for treating tumors and central nervous system (CNS) diseases and for oral administration. However, they lack satisfactory clinical efficacy due to poor extravasation and infiltration through biological barriers to target tissues. Most clinical antitumor NPs have been designed based on enhanced permeability and retention effects which are insufficient and heterogeneous in human tumors.
View Article and Find Full Text PDFBioconjug Chem
January 2025
Guangdong Provincial Key Laboratory of Advanced Biomaterials, Department of Biomedical Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
Nanobodies play an increasingly prominent role in cancer imaging and therapy. However, their efficacy is often constrained by inadequate tumor penetration and rapid clearance from the bloodstream, particularly in brain tumors due to the intractable blood-brain barrier (BBB). Glycosylation is a favorable strategy for modulating the biological functions of nanobodies, including permeability and pharmacokinetics, but it also leads to heterogeneous glycan structures, which affect the targeting ability, stability, and quality of nanobodies.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
The State Key Laboratory of Molecular Engineering of Polymers and Department of Macromolecular Science, Fudan University, Shanghai 200438, P. R China.
Designing artificial enzymes for in vivo catalysis presents a great challenge due to biomacromolecule contamination, poor biodistribution, and insufficient substrate interaction. Herein, we developed single-chain polymeric nanoparticles with Cu/N-heterocyclic carbene active sites (SCNP-Cu) to function as peroxidase mimics for in vivo catalysis and chemo-dynamic therapy (CDT). Compared with the enzyme mimics based on unfolded linear polymer scaffold and multichain cross-linked scaffold, SCNP-Cu exhibits improved tumor accumulation and CDT efficiency both in vitro and in vivo.
View Article and Find Full Text PDFJ Mater Chem B
January 2025
Department of Oncology, Yunfu People's Hospital, Yunfu 527300, Guang Dong, China.
Effective delivery of therapeutic agents for solid tumour treatment is impeded by multiple obstacles, such as aberrant interstitial fluid pressure and high density of the extracellular matrix, which causes impaired penetration to deep avascular tumour tissue that exists in a hypoxic immune cold environment. Only limited tumoricidal effects have been achieved with traditional nanomedicine due to its inefficient penetration and the multiple resistant effects that exist in the tumour microenvironment. Herein, a new chemo-dynamic immunotherapy (CDIT) is proposed based on a transcytosis tumour oxygenator (MnP) with effective chemo-dynamic effects.
View Article and Find Full Text PDFEnviron Sci Technol
January 2025
Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058, China.
Cadmium (Cd) is efficiently transferred from soil to food crops, notably rice. Research indicates that indica rice grains may accumulate more Cd than japonica cultivars; however, differences in Cd bioavailability (the fraction of ingested rice Cd absorbed into the systemic circulation) and toxicity remain unexplored, thus hindering a comprehensive understanding of exposure and health risks. To address this, a mouse bioassay was conducted to evaluate the relative bioavailability (RBA) of Cd in 35 samples each of japonica and indica rice, determining which type exhibits lower Cd bioavailability.
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