Renal-specific nanoparticulate drug delivery systems have shown great potential in reducing systemic side effects and improving the safety and efficacy of treatments for renal diseases. Here, stearic acid-grafted chitosan oligosaccharide (COS-SA) was synthesized as a renal-targeted carrier due to the high affinity of the 2-glucosamine moiety on COS to the megalin receptor expressed on renal proximal tubular epithelial cells. Specifically, COS-SA/CLT micelles were prepared by encapsulating celastrol (CLT) with COS-SA, and different proportions of human serum albumin (HSA) were then adsorbed onto its surface to explore the interaction between the protein corona and cationic polymeric micelles. Our results showed that a multilayered protein corona, consisting of an inner \"hard\" corona and an outer \"soft\" corona, was formed on the surface of COS-SA/CLT@HSA8, which was beneficial in preventing its recognition and phagocytosis by macrophages. The formation of HSA protein corona on COS-SA/CLT micelles also increased its accumulation in the renal tubules. Furthermore, the electropositivity of COS-SA/CLT micelles affected the conformation of adsorbed proteins to various degrees. During the adsorption process, the protein corona on the surface of COS-SA/CLT@HSA1 was partially denatured. Overall, COS-SA/CLT and COS-SA/CLT@HSA micelles demonstrated sufficient safety with renal targeting potential, providing a viable strategy for the management of ischemia/reperfusion-induced acute kidney injury.

BACKGROUND: Microalbuminuria is associated with several clinical conditions of public health concern. Particularly in diabetic patients, there is routine microalbuminuria screening to understand whether the renal complication has progressed to the microalbuminuria stage or not. Therefore, microalbuminuria detection is a matter of considerable interest. For such detection, the clinical labs rely on immunochemical methods. Nevertheless, the immunochemical methods are believed to be less sensitive for the purpose. So, the need arises for continuous research in the field. We believe that pseudoesterase activity of the excreted albumin in microalbuminuria cases is a potential target. This aspect is investigated here and it is shown that the excreted albumin in diabetic microalbuminuria cases retains its pseudoesterase activity, unlike the overt albuminuria cases.
METHODS: The cases of diabetic nephropathy and healthy controls were included in the study. The patients were divided into diabetic controls microalbuminuria, and overt albuminuria group considering the ACR ratio. The urinary proteins of the cases were isolated by centrifugation. The obtained protein pellet was then checked for pseudoesterase activity by electrophoretic and fluorescence-based methods. The CD spectroscopy and LC-MS study was carried out to show the suitability of the substrate for the detection of albumin pseudoesterase activity. To further, understand the structure-function relation, molecular docking studies were carried out.
RESULTS: From the CD and LC-MS study the suitability of the used substrate was confirmed. The electrophoretic and fluorescence study showed that the protein of the microalbuminuria group retained the pseudoesterase activity whereas the same is lost in the overt albuminuria group. The molecular docking studies indicated that a change in albumin structure may result in a change in its pseudoesterase activity.
CONCLUSIONS: The urinary protein of diabetic microalbuminuria cases exhibits pseudoesterase activity. It distinguishes the excreted protein in the diabetic albuminuria group and the overt albuminuria group. This is the first study that showed the retention of pseudoesterase property in excreted albumin. Further, in this study a simple test is developed that distinguishes the excreted albumin in the microalbuminuria group and overt albuminuria group.

OBJECTIVE: Nitric oxide (NO) has various physiological activities. In this study, diclofenac (DF) which has a high affinity for human serum albumin (HSA) was nitrosylated to a novel NO donor (NDF). The cytotoxic effects and the mechanism of NDF were investigated.
METHODS: Binding experiments of NDF to HSA were performed by the ultrafiltration method. NO was measured by the Griess method. The number of dead cells were measured using annexin V. Apoptosis and endoplasmic reticulum stress were evaluated by western blotting.
RESULTS: NDF competitively inhibits the binding of DF to HSA, suggesting that NDF and DF have equivalent binding characteristics. NDF rapidly released NOx after being dissolved. At 200 μM, NDF induced cell death in human pancreatic cancer cells. Western blotting showed that NDF promoted the cleavage of PARP, caspase-3, and caspase-7. Inhibitors of caspase-1 and caspase-9 significantly suppressed NDF-induced cell death, as did a non-specific caspase inhibitor (Z-VAD). In addition, NDF significantly increased the expression of the endoplasmic reticulum stress marker, CHOP.
CONCLUSIONS: NDF induces apoptotic cell death by causing endoplasmic reticulum stress. The findings of this study suggest that NDF may become a promising compound for the treatment of pancreatic cancer.

Prussian Blue nanoparticles (PBnps) are now popular in nanomedicine thanks to the FDA approval of PB. Despite the numerous papers suggesting or describing the in vivo use of PBnps, no studies have been carried out on the formation of a protein corona on the PBnp surface and its stabilizing role. In this paper, we studied qualitatively and quantitatively the corona formed by the most abundant protein of blood, human serum albumin (HSA). Cubic PBnps (41 nm side), prepared in citric acid solution at PB concentration 5 × 10-4 M, readily form a protein corona by redissolving ultracentrifuged PBnp pellets in HSA solutions, with CHSA ranging from 0.025 to 7.0 mg/mL. The basic decomposition of PBnp@HSA was studied in phosphate buffer at the physiological pH value of 7.4. Increased stability with respect to uncoated PBnps was observed at all concentrations, but a minimum CHSA value of 3.0 mg/mL was determined to obtain stability identical to that observed at serum-like HSA concentrations (35-50 mg/mL). Using a modified Lowry protocol, the quantity of firmly bound HSA in the protein corona (hard corona) was determined for all the CHSA used in the PBnp@HSA synthesis, finding increasing quantities with increasing CHSA. In particular, an HSA/PBnp number in the 1500-2300 range was found for CHSA 3.0-7.0 mg/mL, largely exceeding the 180 HSA/PBnp value calculated for an HSA monolayer on a PBnp. Finally, the stabilization brought by the HSA corona allowed us to carry out pH-spectrophotometric titrations on PBnp@HSA in the 3.5-9-0 pH range, revealing a pKa value of 6.68 for the water molecules bound to the Fe3+ centers on the PBnp surface, whose deprotonation is responsible for the blue-shift of the PBnp band from 706 nm (acidic solution) to 685 nm (basic solution).

Carbapenem-resistant Acinetobacter baumannii (CRAB) is a major human pathogen and a research priority for developing new antimicrobial agents. CRAB is a causative agent of a variety of infections in different body sites. One of the manifestations is catheter-associated urinary tract infection, which exposes the bacteria to the host\'s urine, creating a particular environment. Exposure of two CRAB clinical isolates, AB5075 and AMA40, to human urine (HU) resulted in the differential expression levels of 264 and 455 genes, respectively, of which 112 were common to both strains. Genes within this group play roles in metabolic pathways such as phenylacetic acid (PAA) catabolism, the Hut system, the tricarboxylic acid (TCA) cycle, and other processes like quorum sensing and biofilm formation. These results indicate that the presence of HU induces numerous adaptive changes in gene expression of the infecting bacteria. These changes presumably help bacteria establish and thrive in the hostile conditions in the urinary tract. These analyses advance our understanding of CRAB\'s metabolic adaptations to human fluids, as well as expand knowledge on bacterial responses to distinct human fluids containing different concentrations of human serum albumin (HSA).

This study explored how high hydrostatic pressure (HHP) and proteins (i.e., BSA and HSA) influence the color and chemical stability of cyanidin-3-O-glucoside (C3G) at neutral pH. HHP treatments (100-500 MPa, 0-20 min, 25 °C) did not affect C3G content in phosphate buffer (PB) and MOPS buffer. However, significant color loss of C3G occurred in PB due to pressure-induced pH reduction (e.g., from 7 to 4.8 at 500 MPa), which accelerated the hydration of C3G, converting it from colored to colorless species. Consequently, MOPS buffer was employed for subsequent stability experiments to assess the impact of protein and HHP on the thermal, storage, and UV light stability of C3G. Initially, rapid color loss occurred during heating and storage, primarily due to the reversible hydration of C3G until equilibrium with colorless species was reached, followed by slower parallel degradation. HSA increased the fraction of colored species at equilibrium but accelerated thermal degradation, while BSA had minimal effects. UV light irradiation accelerated the degradation of C3G colored species, causing direct degradation without conversion to colorless species, a process further intensified by the presence of proteins. HHP exhibited a negligible effect on C3G stability regardless of protein addition. These findings provide insights into anthocyanin stability under HHP and protein interactions, contributing to the development of future formulation and processing strategies for improved stability and broader applications.

A number of quinoidal molecules with symmetric end-capping groups, particularly dicyanomethylene units, have been synthesized for organic optoelectronic materials. In comparison, dissymmetric quinoidal molecules, characterized by end-capping with different groups, are less explored. In this paper, we present the unexpected formation of new formal quinoidal molecules, which are end-capped with both dicyanomethylene and triphenylphosphonium moieties. The structures of these dissymmetric quinoidal molecules were firmly verified by single crystal structural analyses. On the basis of the control experiments and DFT calculations, we proposed the reaction mechanism for the formation of these dissymmetric quinoidal molecules. The respective zwitterionic forms should make contributions to the ground state structures of these quinoidal molecules based on the analysis of their bond lengths and aromaticity and Mayer Bond Orbital (MBO) calculation. This agrees well with the fact that negative solvatochromism was observed for these quinoidal molecules. Although these new quinoidal molecules are non-emissive both in solutions and crystalline states, they become emissive with quantum yields up to 51.4% after elevating the solvent viscosity or dispersing them in a PMMA matrix. Interestingly, their emissions can also be switched on upon binding with certain proteins, in particular with human serum albumin.

CONCLUSIONS: In an effort to expedite the publication of articles, AJHP is posting manuscripts online as soon as possible after acceptance. Accepted manuscripts have been peer-reviewed and copyedited, but are posted online before technical formatting and author proofing. These manuscripts are not the final version of record and will be replaced with the final article (formatted per AJHP style and proofed by the authors) at a later time.
OBJECTIVE: The purpose of this article is to discuss how the structural and presumably functional integrity of albumin, as described by the concept of effective albumin concentration (eAlb), has potentially important clinical implications beyond the total albumin concentration (tAlb) routinely reported by clinical laboratories.
CONCLUSIONS: Albumin has several functions beyond its oncotic effects, including molecule binding, substance transport, detoxification actions, and serving as an antioxidant. However, there are conformational changes that occur during or following the manufacture of albumin and during its administration to patients with various disease states, such as decompensated liver disease, that often impair these functions. Such impairments are not reflected in tAlb values reported by clinical laboratories and might explain the disconnect often seen between albumin\'s proposed beneficial mechanistic functions and its less-than-predicted clinical effectiveness as noted in published studies. The concept of eAlb has been introduced to describe albumin with structural and functional integrity. Limited studies have found associations between eAlb values and patient prognostic indicators, but the techniques used to decide these effective concentrations to date are complicated and require specialized equipment and experienced researchers for proper interpretation.
CONCLUSIONS: Estimation of eAlb may provide valuable information on the functional ability of albumin beyond the tAlb reported by clinical laboratories, but more research is needed to decide how this information is best used in the clinical setting.

The significant health risks of nanoplastics (NPs) and cadmium (Cd) are currently attracting a great deal of attention and research. At present, the effects and mechanisms of NPs and Cd on human serum albumin (HSA), a key functional protein in the organism on transportation, remain unknown. Here, the differences in the effects and mechanisms of action of Cd alone and composite systems (NPsCd) were explored by enzyme activity assay, multi-spectroscopy analysis and molecular docking. The results showed that HSA activity was inhibited and decreased to 80 % and 69.55 % (Cd = 30 mg/L) by Cd alone and NPs-Cd exposure, respectively. Exposure to Cd induced backbone disruption and protein defolding of HSA, and secondary structure disruption was manifested by the reduction of α-helix. Cd exposure also induces fluorescence sensitization of HSA. Notably, the addition of NPs further exacerbated the effects associated with Cd exposure, which was consistent with the changes in HSA activity. Thus, the above conformational changes may be responsible for inducing the loss of enzyme activity. Moreover, it was determined by RLS spectroscopy that NPs-Cd bound to HSA in the form of protein crowns. Molecular docking has further shown that Cd binds to the surface of Sudlow site II of HSA, suggesting that Cd impairs the function of HSA by affecting the protein structure. More importantly, the addition of NPs further exacerbated the disruption of the protein structure by the adherent binding of HSA on the surface of the plastic particles, which induced a greater change in the enzyme activity. This study provides useful perspectives for investigating the impact of composite pollution on HSA of human functional proteins.

OBJECTIVE: Methylglyoxal (MG) is the most potent precursor during the formation of the advanced glycation end products (AGEs). MG-dependent glycative stress contributes to pathogenesis of diabetes, age-related disorders, and cancer. There is a great need to study the reduction process of glycative stress for effective management of metabolic disorders. From natural compounds to synthetic drugs, each element contributes to the reduction of glycative stress. Previously, it was established that the lowering of uric acid, low-density lipoprotein cholesterol, and urine albumin excretion rate, as well as reducing total oxidative stress, were all achieved more effectively with a levothyroxine regimen. Still, there is no such study found that supports the MG-dependent glycative stress reduction with thyroid hormone compound. Our study aims to investigate the effects of T3 and T4 on MG-dependent glycative stress.
METHODS: The antiglycation effect was assayed through NBT assay, DNPH assay, ELISA, and fluorescence spectrophotometer. The intracellular reduction in reactive oxygen species (ROS) has been estimated through confocal microscopy.
RESULTS: The results revealed an effective reduction in the formation of AGEs adducts and intracellular ROS formation.
CONCLUSIONS: The investigation concludes AGEs formation was suppressed using these compounds, although in vivo and rigorous clinical trials are required in order to verify these findings.