Natural Phyto-Antioxidant Albumin Nanoagents to Treat Advanced Alzheimer's Disease.

Phytotherapeutic approaches are of immense value in the treatment of advanced Alzheimer's disease (AD) because of their diverse biological components and potential multitarget mechanisms. In this study, quercetin, a natural neuroprotective flavonoid, was encapsulated in human serum albumin to obtain HSA@QC nanoparticles (HQ NPs) as a natural phyto-antioxidant albumin nanoagent for the treatment of advanced AD. HQ NPs showed excellent antioxidant effects and protected PC12 cells from H2O2-induced oxidative damage. The intranasal administration of HQ NPs in 11-month-old APP/PS1 mice, which represented advanced AD, effectively prevented the loss of body weight, increased survival rates, and significantly reduced oxidative stress, Aß aggregation, neuronal apoptosis, and synaptic damage in the brain. It also ultimately reversed severely impaired cognitive function. In addition to their favorable anti-AD effects, HQ NPs exhibited excellent biosafety and biocompatibility owing to their natural composition and are expected to become an ideal choice for future drug development and clinical applications.

Toluene diisocyanate-induced inflammation and airway remodeling involves autophagy in human bronchial epithelial cells.

Toluene-diisocyanate (TDI) is one of the main causes of occupational asthma. To study the role of autophagy in TDI-induced airway inflammation and airway remodeling in bronchial airway epithelial (16HBE) cells. We treated 16HBE cells with TDI-human serum albumin (TDI-HSA) conjugate to observe reactive oxygen species (ROS) release, autophagy activation, airway inflammation and airway remodeling. 3-Methyladenine (3-MA) and Rapamycin (Rapa) intervention were used to explore the effects of autophagy on inflammatory response and protein expression related to airway remodeling in 16HBE cells treated with TDI-HSA. Experimental results suggested that various concentrations of TDI-HSA (0, 40, 80 and 120 µg/mL) increased the release of ROS and the expression of Nrf2, activated autophagy and increased the expression of AMPK, Beclin-1, LC3 and decreased the expression of p62, promoted the levels of IL-5, IL-6 and IL-8 in 16HBE cells. Results also showed that E-cadherin expression decreased but an increase was observed in α-SMA and MMP-9 in the TDI-HSA group. The treatment of TDI-HSA combined with Rapa aggravated the above reaction whereas the inverse was true for TDI-HSA combined with 3-MA. These results indicated that autophagy is involved in TDI-induced airway inflammation and airway remodeling as a positive regulatory mechanism, inhibiting autophagy can significantly alleviate the TDI-induced inflammatory response and attenuate airway remodeling protein expression in 16HBE cells.

A non-viral nano-delivery system targeting epigenetic methyltransferase EZH2 for precise acute myeloid leukemia therapy.

Acute myeloid leukemia (AML), which is common in the elderly population, accounts for poor long-term survival with a high possibility of relapse. The associated lack of currently developed therapeutics is directing the search for new therapeutic targets relating to AML. EZH2 (Enhancer of Zeste Homolog 2) is a histone methyltransferase member of the polycomb-group (PcG) family, and its significant overexpression in AML means it has emerged as a potential epigenetic target. Here, we propose the human serum albumin (HSA) nanoparticle based delivery of small interfering RNA (siRNA), which can target EZH2-expressing genes in AML. EZH2 specific siRNA loaded in a polyethyleneimine (PEI) conjugated HSA nanocarrier can overcome the systemic instability of siRNA and precisely target the AML cell population for increased EZH2 gene silencing. A stable nanosized complex (HSANPs-PEI@EZH2siRNA), achieved via the electrostatic interaction of PEI and EZH2 siRNA, shows increased systemic stability and hemocompatibility, and enhanced EZH2 gene silencing activity in vitro, compared to conventional transfection reagents. HSANPs-PEI@EZH2siRNA-treated AML cells showed downregulated EZH2, which is associated with a reduced level of Bmi-1 protein, and H3K27me3 and H2AK119ub modification. The ubiquitin-mediated proteasomal degradation pathway plays a critical role in the downregulation of associated proteins following HSANPs-PEI@EZH2siRNA exposure to AML cells. c-Myb is the AML-responsive transcription factor that directly binds on the EZH2 promoter and was downregulated in HSANPs-PEI@EZH2siRNA-treated AML cells. The systemic exposure to HSANPs-PEI@EZH2siRNA of AML engrafted immunodeficient nude mice displayed efficient EZH2 gene silencing and a reduced AML cell population in peripheral blood and bone marrow. The present study demonstrates a non-viral siRNA delivery system for epigenetic targeting based superior anti-leukemic therapy.

Functionalisation of a heat-derived and bio-inert albumin hydrogel with extracellular matrix by air plasma treatment.

Albumin-based hydrogels are increasingly attractive in tissue engineering because they provide a xeno-free, biocompatible and potentially patient-specific platform for tissue engineering and drug delivery. The majority of research on albumin hydrogels has focused on bovine serum albumin (BSA), leaving human serum albumin (HSA) comparatively understudied. Different gelation methods are usually employed for HSA and BSA, and variations in the amino acid sequences of HSA and BSA exist; these account for differences in the hydrogel properties. Heat-induced gelation of aqueous HSA is the easiest method of synthesizing HSA hydrogels however hydrogel opacity and poor cell attachment limit their usefulness in downstream applications. Here, a solution to this problem is presented. Stable and translucent HSA hydrogels were created by controlled thermal gelation and the addition of sodium chloride. The resulting bio-inert hydrogel was then subjected to air plasma treatment which functionalised its surface, enabling the attachment of basement membrane matrix (Geltrex). In vitro survival and proliferation studies of foetal human osteoblasts subsequently demonstrated good biocompatibility of functionalised albumin hydrogels compared to untreated samples. Thus, air plasma treatment enables functionalisation of inert heat-derived HSA hydrogels with extracellular matrix proteins and these may be used as a xeno-free platform for biomedical research or cell therapy.

Empagliflozin reduces high glucose-induced oxidative stress and miR-21-dependent TRAF3IP2 induction and RECK suppression, and inhibits human renal proximal tubular epithelial cell migration and epithelial-to-mesenchymal transition.

Proximal tubular epithelial cells (PTEC) in the S1 segment of the kidney abundantly express sodium-glucose co-transporters (SGLT) that play a critical role in whole body glucose homeostasis. We recently reported suppression of RECK (Reversion Inducing Cysteine Rich Protein with Kazal Motifs), a membrane anchored endogenous MMP inhibitor and anti-fibrotic mediator, in the kidneys of db/db mice, a model of diabetic kidney disease (DKD), as well as in high glucose (HG) treated human kidney proximal tubule cells (HK-2). We further demonstrated that empagliflozin (EMPA), an SGLT2 inhibitor, reversed these effects. Little is known regarding the mechanisms underlying RECK suppression under hyperglycemic conditions, and its rescue by EMPA. Consistent with our previous studies, HG (25 mM) suppressed RECK expression in HK-2 cells. Further mechanistic investigations revealed that HG induced superoxide and hydrogen peroxide generation, oxidative stress-dependent TRAF3IP2 upregulation, NF-κB and p38 MAPK activation, inflammatory cytokine expression (IL-1ß, IL-6, TNF-α, and MCP-1), miR-21 induction, MMP2 activation, and RECK suppression. Moreover, RECK gain-of-function inhibited HG-induced MMP2 activation and HK-2 cell migration. Similar to HG, advanced glycation end products (AGE) induced TRAF3IP2 and suppressed RECK, effects that were inhibited by EMPA. Importantly, EMPA treatment ameliorated all of these deleterious effects, and inhibited epithelial-to-mesenchymal transition (EMT) and HK-2 cell migration. Collectively, these findings indicate that hyperglycemia and associated AGE suppress RECK expression via oxidative stress/TRAF3IP2/NF-κB and p38 MAPK/miR-21 induction. Furthermore, these results suggest that interventions aimed at restoring RECK or inhibiting SGLT2 have the potential to treat kidney inflammatory response/fibrosis and nephropathy under chronic hyperglycemic conditions, such as DKD.

Smart textiles in wound care: functionalization of cotton/PET blends with antimicrobial nanocapsules.

Management of infected wounds is one of the most costly procedures in the health care sector. Burn wounds are of significant importance due to the high infection risk that can possibly lead to severe consequences such as sepsis. Because antibiotic wound treatments have caused increasing antibiotic resistance in bacteria, there is currently a strong need for alternative strategies. Therefore, we developed new antimicrobial wound dressings consisting of pH-responsive human serum albumin/silk fibroin nanocapsules immobilized onto cotton/polyethylene terephthalate (PET) blends loaded with eugenol, which is an antimicrobial phenylpropanoid. Ultrasound-assisted production of eugenol-loaded nanocapsules resulted in particle sizes (hydrodynamic radii) between 319.73 ± 17.50 and 574.00 ± 92.76 nm and zeta potentials ranging from -10.39 ± 1.99 mV to -12.11 ± 0.59 mV. Because recent discoveries have indicated that the sweat glands contribute to wound reepithelialisation, release studies of eugenol were conducted in different artificial sweat formulas that varied in pH. Formulations containing 10% silk fibroin with lower degradation degree exhibited the highest release of 41% at pH 6.0. After immobilization, the functionalized cotton/PET blends were able to inhibit 81% of Staphylococcus aureus and 33% of Escherichia coli growth. Particle uniformity, silk fibroin concentration, and high surface-area-to-volume ratio of the produced nanocapsules were identified as the contributing factors leading to high antimicrobial activities against both strains. Therefore, the production of antimicrobial textiles using nanocapsules loaded with an active natural compound that will not contribute to antibiotic resistance is seen as a potential future alternative to commercially available antiseptic wound dressings.

Optimised approach to albumin-drug conjugates using monobromomaleimide-C-2 linkers.

Conjugation of therapeutics to human serum albumin (HSA) using bromomaleimides represents a promising platform for half-life extension. We show here that the Cys-34 crevice substantially reduces the rate of serum stabilising maleimide hydrolysis in these conjugates, necessitating reagent optimisation. This improved reagent design is applied to the construction of an HSA-paclitaxel conjugate, preventing drug loss during maleimide hydrolysis.

Effects of resuscitation with human albumin 5%, hydroxyethyl starch 130/0.4 6%, or crystalloid on kidney damage in an ovine model of septic shock.

BACKGROUND: Colloid solutions have been associated with kidney dysfunction in septic animals and humans. The present study investigated the influence of resuscitation with human albumin (HA) 5%, hydroxyethyl starch (HES) 130/0.4 6%, and balanced crystalloids on ultrastructural kidney damage, kidney function, and survival in a model of ovine septic shock. METHODS: After induction of peritoneal septic shock, animals were randomised to one of the following groups: (1) HA 5%, (2) HES 130/0.4 6%, (3) balanced crystalloid, and (4) control (each n=10). Causal therapy included re-laparotomy, peritoneal lavage, and antimicrobial therapy. Sequential kidney biopsies were obtained for the assessment of the electron microscopic tubular injury (EMTI) score. RESULTS: Serum creatinine and urea were highest in the control group, and there were no differences between the intervention groups. Cumulative diuresis was significantly higher in the HA group [1.0 ml kg-1 h-1 (0.6; 1.2)] compared with control [0.7 ml kg-1 h-1 (0.6; 0.9), P<0.05]. Creatinine clearance was highest in the HA and crystalloid groups. Ultrastructural kidney damage was highest in the control group [EMTI score 7.8 (6.7; 9.0)] without differences between intervention groups. Survival was 100% in the colloid groups vs 90% (crystalloid) and 60% (control, all P<0.05). CONCLUSION: In an ovine model of septic shock, kidney function and cumulative diuresis were preserved in the 5% albumin and crystalloid resuscitation groups, whereas HES 130/0.4 6% resulted in diminished creatinine clearance. Differences in kidney function between resuscitation fluids could not be explained by differences in ultrastructural kidney damage. CLINICAL TRIAL REGISTRATION: 84-02.04.2011.A300.

Vitamin D Ameliorates Impaired Wound Healing in Streptozotocin-Induced Diabetic Mice by Suppressing Endoplasmic Reticulum Stress.

BACKGROUND: This study is designed to investigate whether vitamin D promotes diabetic wound healing and explore the potential mechanism which may be involved in the healing process. MATERIAL AND METHODS: Human umbilical vein endothelial cells (HUVECs) were treated with 200 µg/ml of advanced glycation end product-modified human serum albumin (AGE-HSA) and 250 mg/dl of glucose with vitamin D. Cell viability was analyzed using the CCK-8 assay, and the apoptosis rate was measured using flow cytometry. Endogenous markers of ER stress were quantified using Western blot and a real-time polymerase chain reaction. Diabetic mice were treated with vitamin D (100 ng/kg per day) for 14 days. The ulcer area and ulcerative histology were detected dynamically. RESULTS: Vitamin D administration not only decreased the apoptosis rate but also increased cell viability. Furthermore, the expression of endogenous markers of ER stress was downregulated as a result of vitamin D treatment. Vitamin D supplementation significantly accelerated wound healing of diabetic mice and improved the healing quality. Further studies showed that reduced ER stress was associated with the positive outcome. CONCLUSION: These results suggest that vitamin D may ameliorate impaired wound healing in diabetic mice by suppressing ER stress.