A head-to-head comparison of polymer interaction with mucin from porcine stomach and bovine submaxillary glands.

Native mucus is heterogeneous, displays high inter-individual variation and is prone to changes during harvesting and storage. To overcome the lack of reproducibility and availability of native mucus, commercially available purified mucins, porcine gastric mucin (PGM) and mucin from bovine submaxillary gland (BSM), have been widely used. However, the question is to which extent the choice of mucin matters in studies of their interaction with polymers as their composition, structure and hence physicochemical properties differ. Accordingly, the interactions between PGM or BSM with two widely used polymers in drug delivery, polyethylene oxide and chitosan, was studied with orthogonal methods: turbidity, dynamic light scattering, and quartz crystal microbalance with dissipation monitoring. Polymer binding and adsorption to the two commercially available and purified mucins, PGM and BSM, is different depending on the mucin type. PEO, known to interact weakly with mucin, only displayed limited interaction with both mucins as confirmed by all employed methods. In contrast, chitosan was able to bind to both PGM and BSM. Interestingly, the results suggest that chitosan interacts with BSM to a greater extent than with PGM indicating that the choice of mucin, PGM or BSM, can affect the outcome of studies of mucin interactions with polymers.

Protocol for detecting palmitoylation of high-molecular-weight rat synaptic proteins via acyl-PEG labeling.

Here, we present an optimized acyl-PEGyl exchange gel shift (APEGS) assay to monitor palmitoylation of high-molecular-weight proteins from primary neuronal cultures. We describe steps for culturing cortical neurons from rat embryos and expressing proteins of interest. We then detail procedures for employing a fatty acyl exchange technique wherein hydroxylamine is used to cleave palmitic acid from the palmitoyl-thioester bond, exposing cysteine residues that are subsequently labeled with methoxy polyethylene glycol maleimide (mPEG-MAL-10k). For complete details on the use and execution of this protocol, please refer to Yucel et al.1.

Three-Dimensional Lymphatics-on-a-Chip Reveals Distinct, Size-Dependent Nanoparticle Transport Mechanisms in Lymphatic Drug Delivery.

Although nanoparticle-based lymphatic drug delivery systems promise better treatment of cancer, infectious disease, and immune disease, their clinical translations are limited by low delivery efficiencies and unclear transport mechanisms. Here, we employed a three-dimensional (3D) lymphatics-on-a-chip featuring an engineered lymphatic vessel (LV) capable of draining interstitial fluids including nanoparticles. We tested lymphatic drainage of different sizes (30, 50, and 70 nm) of PLGA-b-PEG nanoparticles (NPs) using the lymphatics-on-a-chip device. In this study, we discovered that smaller NPs (30 and 50 nm) transported faster than larger NPs (70 nm) through the interstitial space, as expected, but the smaller NPs were captured by lymphatic endothelial cells (LECs) and accumulated within their cytosol, delaying NP transport into the lymphatic lumen, which was not observed in larger NPs. To examine the mechanisms of size-dependent NP transports, we employed four inhibitors, dynasore, nystatin, amiloride, and adrenomedullin, to selectively block dynamin-, caveolin-, macropinocytosis-mediated endocytosis-, and cell junction-mediated paracellular transport. Inhibiting dynamin using dynasore enhanced the transport of smaller NPs (30 and 50 nm) into the lymphatic lumen, minimizing cytosolic accumulation, but showed no effect on larger NP transport. Interestingly, the inhibition of caveolin by nystatin decreased the lymphatic transport of larger NPs without affecting the smaller NP transport, indicating distinct endocytosis mechanisms used by different sizes of NPs. Macropinocytosis inhibition by amiloride did not change the drainage of all sizes of NPs; however, paracellular transport inhibition by adrenomedullin blocked the lymphatic transport of NPs of all sizes. We further revealed that smaller NPs were captured in the Rab7-positive late-stage lymphatic endosomes to delay their lymphatic drainage, which was reversed by dynamin inhibition, suggesting that Rab7 is a potential target to enhance the lymphatic delivery of smaller NPs. Together, our 3D lymphatics-on-a-chip model unveils size-dependent NP transport mechanisms in lymphatic drug delivery.

Selective biodegradation of octylphenol polyethoxylates with different ethoxylate length chains by aerobic bacterial culture.

Octylphenol polyethoxylates (OPEOn) are composed of a hydrophobic octylphenol (OP) group and a hydrophilic polyethylene oxide (EO) chain and are widely used in commercial products. Shorter EO chains and OPEOn biometabolites have been identified as endocrine-disrupting contaminants and can threaten biotic factors in the ecosystem. In this study, OPEOn at three EO lengths (TX-45, TX-114, and TX-165) were selected in monomer (MN) or micelle (MC) state for batch experiments under aerobic conditions, with results showing biodegradation rates of 90 % within 35-70 h. The pseudo-first-order constant (k) of OPEOn biodegradation was observed in the order TX-45 (0.1414 h-1) > TX-114 (0.0556 h-1) > TX-165 (0.0485 h-1), with biomineralisation reaching at least 80 % for all OPEOn. The selective biodegradation of EO chains was also measured, with initial accumulation of OPEO3 observed along with the depletion of longer EO chains for TX-45 and TX-114 in both the MN and MC states. A similar trend was observed for the MN state of TX-165, with OPEO3-OPEO9 observed to accumulate and reduced after 70 h. MC biodegradation was accomplished via the initial accumulation of OPEO3-OPEO9. The amounts of OPEO3 increased and others reduced; however, OPEO3 remained high at the end of biodegradation for TX-165. Bacterial community analysis indicated that the genera Sphingobium spp., Pseudomonas spp., Flavobacterium spp., Comamonas spp., and Sphingopyxis spp. dominate OPEOn biodegradation, and they have their roles during biodegradation, and the community-level physiological profile (CLPP) was also changed by biodegradation in both the MN and MC states.

Intravitreal Delivery of PEGylated-ECO Plasmid DNA Nanoparticles for Gene Therapy of Stargardt Disease.

OBJECTIVE: Current gene therapy of inherited retinal diseases is achieved mainly by subretinal injection, which is invasive with severe adverse effects. Intravitreal injection is a minimally invasive alternative for gene therapy of inherited retinal diseases. This work explores the efficacy of intravitreal delivery of PEGylated ECO (a multifunctional pH-sensitive amphiphilic amino lipid) plasmid DNA (pGRK1-ABCA4-S/MAR) nanoparticles (PEG-ELNP) for gene therapy of Stargardt disease. METHODS: Pigmented Abca4-/- knockout mice received 1 µL of PEG-ELNP solution (200 ng/uL, pDNA concentration) by intravitreal injections at an interval of 1.5 months. The expression of ABCA4 in the retina was determined by RT-PCR and immunohistochemistry at 6 months after the second injection. A2E levels in the treated eyes and untreated controls were determined by HPLC. The safety of treatment was monitored by scanning laser ophthalmoscopy and electroretinogram (ERG). RESULTS: PEG-ELNP resulted in significant ABCA4 expression at both mRNA level and protein level at]6 months after 2 intravitreal injections, and a 40% A2E accumulation reduction compared with non-treated controls. The PEG-ELNP also demonstrated excellent safety as shown by scanning laser ophthalmoscopy, and the eye function evaluation from electroretinogram. CONCLUSIONS: Intravitreal delivery of the PEG-ELNP of pGRK1-ABCA4-S/MAR is a promising approach for gene therapy of Stargardt Disease, which can also be a delivery platform for gene therapy of other inherited retinal diseases.

A polyethylene glycol-grafted pullulan polysaccharide adhesive improves drug loading capacity and release efficiency.

In this study, polyethylene glycol was grafted onto pullulan polysaccharides, resulting in the development of a novel adhesive termed PLUPE, offering superior drug loading capacity and rapid release efficiency. The efficacy of PLUPE was rigorously evaluated through various tests, including the tack test, shear strength test, 180° peel strength test, and human skin adhesion test. The results demonstrated that PLUPE exhibited a static shear strength that was 4.6 to 9.3 times higher than conventional PSAs, ensuring secure adhesion for over 3 days on human skin. A comprehensive analysis, encompassing electrical potential evaluation, calculation of interaction parameters, and FT-IR spectra, elucidated why improved the miscibility between the drug and PSAs, that the significant enhancement of intermolecular hydrogen bonding in the PLUPE structure. ATR-FTIR, rheological, and thermodynamic analyses further revealed that the hydrogen bonding network in PLUPE primarily interacted with polar groups in the skin. This interaction augmented the fluidity and free volume of PSA molecules, thereby promoting efficient drug release. The results confirmed the safety profile of PLUPE through skin irritation tests and MTT assays, bolstering its viability for application in TDDS patches. In conclusion, PLUPE represented a groundbreaking adhesive solution for TDDS patches, successfully overcoming longstanding challenges associated with PSAs.

Radiotherapy Metastatic Prostate Cancer Cell Lines Treated with Gold Nanorods Modulate miRNA Signatures.

MicroRNA (miRNA) modulation has been identified as a promising strategy for improving the response of human prostate cancer (PCa) to radiotherapy (RT). Studies have shown that mimics or inhibitors of miRNAs could modulate the sensitivity of PCa cells to RT. In addition, pegylated gold nanoparticles have been studied as a therapeutic approach to treat PCa cells and/or vehicles for carrying miRNAs to the inside of cells. Therefore, we evaluated the capacity of hypofractionated RT and pegylated gold nanorods (AuNPr-PEG) to modulate the miRNA signature on PCa cells. Thus, RT-qPCR was used to analyze miRNA-95, miRNA-106-5p, miRNA-145-5p, and miRNA-541-3p on three human metastatic prostate cell lines (PC3, DU145, and LNCaP) and one human prostate epithelial cell line (HprEpiC, a non-tumor cell line) with and without treatment. Our results showed that miRNA expression levels depend on cell type and the treatment combination applied using RT and AuNPr-PEG. In addition, cells pre-treated with AuNPr-PEG and submitted to 2.5 Gy per day for 3 days decreased the expression levels of miRNA-95, miRNA-106, miRNA-145, and miRNA-541-3p. In conclusion, PCa patients submitted to hypofractionated RT could receive personalized treatment based on their metastatic cellular miRNA signature, and AuNPr-PEG could be used to increase metastatic cell radiosensitivity.

Preparation of Degradable and Transformable Core-Corona-Type Particles that Control Cellular Uptake by Thermal Shape Change.

Particle-cell interactions, such as cellular uptake, vary depending on the particle size, shape, and surface properties. By dynamic control of the physical properties of particles, microparticle-cell interactions can intentionally be altered. Particle degradability is also necessary for their application in the body. In this study, we aimed to prepare degradable core-corona-type particles that are deformed near the body temperature and investigated particle shape-dependent cellular uptake. Degradable and transformable particles consisting of poly(2-methylene-1,3-dioxepane)-co-poly(ethylene glycol) with three-armed poly(ε-caprolactone) (PCL) were prepared. The particle melting point was controlled by the chain length of the three-armed PCL. Particle degradation occurred under both acidic and alkaline conditions via ester group hydrolysis in the polymer backbones. The rod-shaped microparticles prepared by uniaxial stretching at a temperature above the melting point of the core showed less uptake into macrophages than did the spherical microparticles. Therefore, the degradable transformable particles enable macrophage interaction control via stimuli-regulated particle shapes and are expected to be applied as drug delivery carriers that can be decomposed and excreted from the body.

Cysteine-modified PEGylated nanoparticles for targeted delivery of methylprednisolone to pancreatitis.

The timely suppression of inflammatory mediator production and mitigation of their effects on pancreatic acinar cells are crucial for the successful management of acute pancreatitis. To achieve effective treatment, we present a novel approach utilizing cysteine modified PEG nanoparticles for both precise accumulation at the site of pancreatitis and specific targeting of acinar cells. Methylprednisolone, a nonsteroidal anti-inflammatory drug, was tailored to enhance its circulation time in the bloodstream, preferentially accumulate in the pancreas and enhance cell uptake efficiency by acinar cells through specifically targeting L-Type amino acid transporter 1. The nanosystem significantly downregulated pro-inflammatory cytokines in plasma, resulting in the effective suppression of inflammation in acinar cells within an acute pancreatitis rat model. The utilization of the dual targeted therapy strategy holds considerable potential for the clinical management of pancreatitis.

Highly flexible PEG-LifeAct constructs act as tunable biomimetic actin crosslinkers.

In vitro studies of actin filament networks crosslinked with dynamic actin binding proteins provide critical insights into cytoskeletal mechanics as well as inspiration for new adaptive materials design. However, discontinuous variance in the physiochemical properties of actin binding proteins impedes holistic relationships between crosslinker molecular parameters, network structure, and mechanics. Bio-synthetic constructs composed of synthetic polymer backbones and actin binding motifs would enable crosslinkers with engineered physiochemical properties to directly target the desired structure-property relationships. As a proof of concept, bio-synthetic crosslinkers composed of highly flexible polyethylene glycol (PEG) polymers functionalized with the actin binding peptide LifeAct, are explored as actin crosslinkers. Using bulk rheology and fluorescence microscopy, these constructs are shown to modulate actin filament network structure and mechanics in a contour length dependent manner, while maintaining the stress-stiffening behavior inherent to actin filament networks. These results encourage the design of more diverse and complex peptide-polymer crosslinkers to interrogate and control semi-flexible polymer networks.

Castor (Ricinus communis L.) differential cell cycle and metabolism reactivation, germinability, and seedling performance under NaCl and PEG osmoticum: Stress tolerance related to genotype-preestablished superoxide dismutase activity.

Castor (Ricinus communis) is a relevant industrial oilseed feedstock for many industrial applications, being globally mainly cultivated by smallholder farmers in semiarid areas, where abiotic stresses predominate. Therefore, susceptible to generating reactive oxygen species (ROS) and subsequent oxidative stress, compromising cell metabolism upon seed imbibition and germination, seedling and crop establishment, and yield. The present study evaluated the consequences of water restriction by Polyethylene glycol (PEG) and Sodium chloride (NaCl) on cell cycle and metabolism reactivation on germinability, seedling growth, and vigor parameters in 2 commercial castor genotypes (Nordestina and Paraguaçu). PEG water restriction inhibited germination completely at -0.23 MPa or higher, presumably due to reduced oxygen availability. The restrictive effects of NaCl saline stress on germination were observed only from -0.46 MPa onwards, affecting dry mass accumulation and the production of normal seedlings. In general, superoxide dismutase (SOD) activity increased in NaCl -0.23 MPa, whereas its modulation during the onset of imbibition (24h) seemed to depend on its initial levels in dry seeds in a genotype-specific manner, therefore, resulting in the higher stress tolerance of Nordestina compared to Paraguaçu. Overall, results show that Castor germination and seedling development are more sensitive to the restrictive effects of PEG than NaCl at similar osmotic potentials, contributing to a better understanding of the responses to water restriction stresses by different Castor genotypes. Ultimately, SOD may constitute a potential marker for characterizing castor genotypes in stressful situations during germination, early seedling, and crop establishment, and a target for breeding for Castor-improved stress tolerance.

Oxidation of Hydrogen Sulfide to Polysulfide and Thiosulfate by a Carbon Nanozyme: Therapeutic Implications with an Emphasis on Down Syndrome.

Hydrogen sulfide (H2 S) is a noxious, potentially poisonous, but necessary gas produced from sulfur metabolism in humans. In Down Syndrome (DS), the production of H2 S is elevated and associated with degraded mitochondrial function. Therefore, removing H2 S from the body as a stable oxide could be an approach to reducing the deleterious effects of H2 S in DS. In this report we describe the catalytic oxidation of hydrogen sulfide (H2 S) to polysulfides (HS2+n - ) and thiosulfate (S2 O3 2- ) by poly(ethylene glycol) hydrophilic carbon clusters (PEG-HCCs) and poly(ethylene glycol) oxidized activated charcoal (PEG-OACs), examples of oxidized carbon nanozymes (OCNs). We show that OCNs oxidize H2 S to polysulfides and S2 O3 2- in a dose-dependent manner. The reaction is dependent on O2 and the presence of quinone groups on the OCNs. In DS donor lymphocytes we found that OCNs increased polysulfide production, proliferation, and afforded protection against additional toxic levels of H2 S compared to untreated DS lymphocytes. Finally, in Dp16 and Ts65DN murine models of DS, we found that OCNs restored osteoclast differentiation. This new action suggests potential facile translation into the clinic for conditions involving excess H2 S exemplified by DS.

Exploring the Impact of Nanoparticle Stealth Coatings in Cancer Models: From PEGylation to Cell Membrane-Coating Nanotechnology.

Nanotechnological platforms offer advantages over conventional therapeutic and diagnostic modalities. However, the efficient biointerfacing of nanomaterials for biomedical applications remains challenging. In recent years, nanoparticles (NPs) with different coatings have been developed to reduce nonspecific interactions, prolong circulation time, and improve therapeutic outcomes. This study aims to compare various NP coatings to enhance surface engineering for more effective nanomedicines. We prepared and characterized polystyrene NPs with different coatings of poly(ethylene glycol), bovine serum albumin, chitosan, and cell membranes from a human breast cancer cell line. The coating was found to affect the colloidal stability, adhesion, and elastic modulus of NPs. Protein corona formation and cellular uptake of NPs were also investigated, and a 3D tumor model was employed to provide a more realistic representation of the tumor microenvironment. The prepared NPs were found to reduce protein adsorption, and cell-membrane-coated NPs showed significantly higher cellular uptake. The secretion of proinflammatory cytokines in human monocytes after incubation with the prepared NPs was evaluated. Overall, the study demonstrates the importance of coatings in affecting the behavior and interaction of nanosystems with biological entities. The findings provide insight into bionano interactions and are important for the effective implementation of stealth surface engineering designs.

Polyethylene glycol precipitation is an efficient method to obtain extracellular vesicle-depleted fetal bovine serum.

Mesenchymal stromal/stem cell derived-extracellular vesicles (MSC-EVs) have gained interest as drug delivery nanoparticles, having immunoregulatory and potentiating tissue repair property. To maintain growth of MSCs and obtain pure MSC-derived EVs, the culture media should contain fetal bovine serum (FBS) devoid of EVs, as the presence of FBS EVs confounds the properties of MSC-EVs. Therefore, we tested three methods: 18h ultracentrifugation (UC) and ultrafiltration (UF), which are common FBS EV depletion methods in current MSC-EV research, and polyethylene glycol (PEG) precipitation to obtain three EV depleted FBS (EVdFBS) batches, and compared them to FBS and commercial (Com) EVdFBS on human adipose stem cell (hADSC) growth, differentiation, enrichment of EVs in hADSC supernatant and their biological function on collagen metabolism. Our comparative study showed UC and UF vary in terms of depletion efficiency and do not completely deplete EVs and affects the growth-promoting quality of FBS. Specifically, FBS EV depletion was comparable between PEG (95.6%) and UF (96.6%) but less by UC (82%), as compared to FBS. FBS protein loss was markedly different among PEG (47%), UF (87%), and UC (51%), implying the ratio of EV depletion over protein loss was PEG (2.03), UF (1.11), and UC (1.61). A significant decrease of TGFß/Smad signaling, involving in MSC growth and physiology, was observed by UF. After 96 hours of exposure to 5% FBS or 5% four different EVdFBS cell growth media, the osteogenesis ability of hADSCs was not impaired but slightly lower mRNA expression level of Col2a observed in EVdFBS media during chondrogenesis. In consistent with low confluency of hADSCs observed by optical microscope, cell proliferation in response to 5% UF EVdFBS media was inhibited significantly. Importantly, more and purer ADSCs EVs were obtained from ADSCs cultured in 5% PEG EVdFBS media, and they retained bioactive as they upregulated the expression of Col1a1, TIMP1 of human knee synovial fibroblast. Taken together, this study showed that PEG precipitation is the most efficient method to obtain EV depleted FBS for growth of MSCs, and to obtain MSC EVs with minimal FBS EV contamination.

Systemic delivery of glycosylated-PEG-masked oncolytic virus enhances targeting of antitumor immuno-virotherapy and modulates T and NK cell infiltration.

Rationale: Immuno-virotherapy has emerged as a promising approach for cancer treatment, as it directly and cytotoxically eliminates tumors with systemic immune stimulation. However, the clinical efficacy of this approach remains limited by inappropriate delivery routes, robust antiviral responses, and the tumor immunosuppressive microenvironment. Methods: To address these challenges, we propose a surface engineering strategy that masks oncolytic herpes simplex virus (oHSV) with a galactose-polyethylene-glycol (PEG) polymer chain to minimize host antiviral responses and selectively targets tumors by limiting exposure to circulation upon systemic administration. We evaluated the antitumor efficacy of glycosylated-PEG-oHSV by examining tumor growth in animal models and analyzing tumor-infiltrating CD8+T cells and NK cells in the tumor microenvironment (TME). To assess the neutralizing antibody levels after systemic administration of glycosylated-PEG-oHSV, we utilized a mouse model and measured oHSV-specific IgG. Results: We demonstrate that the glycosylated-PEG modified oHSV does not affect the replication of oHSV yet exhibits high specificity to the asialoglycoprotein receptor (ASGPR) overexpressed in hepatocellular carcinoma cells. This results in selectively targeting cancer cells and deep penetration into tumors while avoiding spreading into the brain. Our approach also effectively reduces oHSV-specific neutralizing antibody levels to mitigate host antiviral immune response. Notably, our glycosylated-PEG-oHSV alleviates the immunosuppressive microenvironment within tumors by reducing regulatory T cells, augmenting the infiltration of activated CD8+T cells and NK cells with increasing release of anti-tumor cytokines, to impede tumor progression. Conclusion: Our findings offer a widely applicable and universal strategy to enhance cancer immuno-virotherapy through systemic administration of non-genetically engineered oncolytic viruses. This approach has the potential to overcome the limitations of current immune-virotherapy strategies and may improve clinical outcomes for cancer patients.

[Efficacy and safety of pegylated interferon alpha-2b for patients with myeloproliferative neoplasm].

Objective: To evaluate the efficacy and safety of pegylated interferon alpha-2b (PEG-IFN-α2b) in the treatment of myeloproliferative neoplasm (MPN). Methods: Thirty-four MPN patients receiving PEG-IFN-α2b treatment in the Second Hospital of Tianjin Medical University from August 2019 to October 2022 were prospectively included. Among the patients, 9 were male and 25 were female, and the median age [M (Q1, Q3)] was 57 (19, 78) years. Patients' clinical characteristics were collected and the follow-up was performed. As of January 30, 2023, the follow-up period [M(Q1, Q3)] was 24 (16, 33) months. The efficacy, safety and changes in immune cell and cytokine levels after 12 and 24 months of treatment were analyzed. Results: During the follow-up period, 4 patients dropped out, and the efficacy was evaluable in 30 patients. Following 12 and 24 months of treatment, the complete hematologic response (CHR) rates were 57.1% (16/28) and 75.0% (18/24), respectively. The complete molecular response (CMR)+partial molecular response (PMR) rates were 27.3% (6/22) and 55.0% (11/20), respectively. The bone marrow histopathological overall response rates (ORR) were 34.6% (9/26) and 47.6% (10/21), respectively. At 12 and 24 months of treatment, the proportions of CD8+HLA-DR+T cells, effector T cell subpopulations, CD56bright natural killer (NK) cells, and plasmacytoid dendritic cells (pDC) were higher than the pre-treatment levels, while the proportion of CD56dim NK cells was lower than the pre-treatment level (all P<0.05). The levels of motif chemokine ligand 10 (CXCL10), tumor necrosis factor (TNF)-α and TNF-ß in bone marrow all increased from those prior to treatment, while the levels of vascular endothelial growth factor (VEGF) and interleukin (IL-4) decreased from those prior to treatment (all P<0.05). Among hematological adverse reactions, white blood cells decrease [47% (16/34)] was observed with high incidence. Among non-hematological adverse reactions, asthenia [44.1% (15/34)] and transaminases increase [32.3% (11/34)] were observed with high incidences. Conclusions: PEG-IFN-α2b has high hematologic, molecular, and bone marrow histopathological response rates in the treatment of MPN. It can reduce malignant clone loads and regulate the immune microenvironment and is safe and well tolerated overall.

Noncanonical mechanism of Nrf2 activation by diacylglycerol polyethylene glycol adducts in normal human epidermal keratinocytes.

Polyethylene glycol-23 glyceryl distearate (GDS-23), a diacylglycerol polyethylene glycol adduct, forms niosomes with a liposome-like structure and functions as an active ingredient in drug delivery systems. In addition, it upregulates antioxidant proteins such as heme oxygenase 1 and NAD(P)H-quinone dehydrogenase 1 in cells. However, the activation of nuclear factor E2-related factor-2 (Nrf2), which plays a role in inducing the expression of antioxidant proteins, and its protective effects induced by GDS-23 treatment against oxidative stress have not been elucidated. This study aimed at verifying the activation of Nrf2 by GDS-23 and clarifying its underlying mechanisms, and investigated whether GDS-23 protects against hydroquinone-induced cytotoxicity. Normal human epidermal keratinocytes were treated with GDS-23. Real-time reverse transcription-polymerase chain reaction, western blotting, and immunostaining were used to investigate the mechanism of Nrf2 activation, and neutral red assay was performed to evaluate cytotoxicity. GDS-23-treated cells showed an increase in antioxidant protein levels and stabilization of Nrf2 in the nucleus. During Nrf2 activation, p62, an autophagy-related adaptor protein, was phosphorylated at Ser349. Inhibition of the interaction between the phosphorylated p62 and Kelch-like ECH-associated protein 1 significantly suppressed the GDS-23-mediated induction of antioxidant protein expression. In addition, hydroquinone-induced cell toxicity was significantly attenuated by GDS-23. GDS-23 induced the intracellular antioxidant system by activating Nrf2 in a p62 phosphorylation-dependent manner without generating oxidative stress in the cells. GDS-23 may be applied as a multifunctional material for drug delivery system that enhances internal antioxidant systems.

Poly(ethylene glycol)-Based Hydrogel Microcarriers Alter Secretory Activity of Genetically Modified Mesenchymal Stromal Cells.

In order to scale up culture therapeutic cells, such as mesenchymal stromal cells (MSCs), culture in suspension bioreactors using microcarriers (µCs) is preferred. However, the impact of microcarrier type on the resulting MSC secretory activity has not been investigated. In this study, two poly(ethylene glycol) hydrogel formulations with different swelling ratios (named "stiffer" and "softer") were fabricated as µC substrates to culture MSCs and MSCs genetically modified to express the interleukin-1 receptor antagonist (IL-1Ra-MSCs). Changes in cell number, secretory and angiogenic activity, and changes in MAPK signaling were evaluated when cultured on hydrogel µCs, as well as on tissue culture plastic-based Synthemax µCs. We demonstrated that culture on stiffer µCs increased secretion of IL-1Ra compared to culture on Synthemax µCs by IL-1Ra-MSCs by 1.2- to 1.6-fold, as well as their in vitro angiogenic activity, compared to culture on Synthemax µCs, while culture on both stiffer and softer µCs altered the secretion of several other factors compared to culture on Synthemax µCs. Changes in angiogenic activity corresponded with increased gene expression and secretion of hepatocyte growth factor by MSCs cultured on softer µCs by 2.5- to 6-fold compared to MSCs cultured on Synthemax µCs. Quantification of phosphoprotein signaling with the MAPK pathway revealed broad reduction of pathway activation by IL-1Ra-MSCs cultured on both stiffer and softer µCs compared to Synthemax, where phosphorylated c-Jun, ATF2, and MEK1 were reduced specifically on softer µCs. Overall, this study showed that µC surfaces can influence the secretory activity of genetically modified MSCs and identified associated changes in MAPK pathway signaling, which is a known central regulator of cytokine secretion.

Gelatin/polyethylene glycol-loaded magnesium hydroxide nanocomposite to attenuate acetylcholinesterase, neurotoxicity, and activation of GPR55 protein in rat models of Alzheimer's disease.

Alzheimer's disease (AD) is a neurodegenerative disease marked by mitochondrial dysfunction, amyloid-ß (Aß) aggregation, and neuronal cell loss. G-protein-coupled receptor 55 (GPR55) has been used as a promising target for insulin receptors in diabetes therapy, but GPR55's role in AD is still unidentified. Gelatin (GE) and polyethylene glycol (PEG) polymeric hydrogels are commonly used in the drug delivery system. Therefore, the aim of the present study was the preparation of magnesium hydroxide nanocomposite using Clitoria ternatea (CT) flower extract, GE, and PEG (GE/PEG/Mg(OH)2NCs) by the green precipitation method. The synthesized GE/PEG/Mg(OH)2NCs were used to determine the effect of GPR55 activation of intracerebroventricular administration on streptozotocin (ICV-STC)-induced cholinergic dysfunction, oxidative stress, neuroinflammation, and cognitive deficits. The GE/PEG/Mg(OH)2NCs were administered following bilateral ICV-STC administration (3 mg/kg) in experimental rats. Neurobehavioral assessments were performed using a Morris water maze (MWM) and a passive avoidance test (PA). Cholinergic and antioxidant activity, oxidative stress, and mitochondrial complex activity were estimated in the cortex and hippocampus through biochemical analysis. Inflammatory markers (TNF-α, IL-6, and IL-1ß) were determined using the ELISA method. Our study results demonstrated that the GE/PEG/Mg(OH)2NCs treatment significantly improved spatial and non-spatial memory functions in behavioral studies. Moreover, the treatment with GE/PEG/Mg(OH)2NCs group significantly attenuated cholinergic dysfunction, oxidative stress, and inflammatory markers, and also highly improved anti-oxidant activity (GSH, SOD, CAT, and GPx) in the cortex and hippocampus regions. The western blot results suggest the activation of the GPR55 protein expression through GE/PEG/Mg(OH)2NCs. The histopathological studies showed clear cytoplasm and healthy neurons, effectively promoting neuronal activity. Furthermore, the molecular docking results demonstrated the binding affinity and potential interactions of the compounds with the AChE enzyme. In conclusion, the GE/PEG/Mg(OH)2NCs treated groups showed reduced neurotoxicity and have the potential as a therapeutic agent to effectively target AD.

Parameterisation and cellular evaluation of poly(ethylene) oxide-coated erbium oxide in MCF-7 cells as MRI diagnostic nanofibres.

The novelty of this work is the conjugation of poly(ethylene) oxide (PEO) with the erbium oxide (Er2O3) nanoparticles using the electrospinning technique. In this work, synthesised PEO-coated Er2O3 nanofibres were characterised and evaluated for their cytotoxicity to assess their potential use as diagnostic nanofibres for magnetic resonance imaging (MRI). PEO has significantly impacted nanoparticle conductivity due to its lower ionic conductivity at room temperature. The findings showed that the surface roughness was improved over the nanofiller loading, implying an improvement in cell attachment. The release profile performed for drug-controlling purposes has demonstrated a stable release after 30 min. Cellular response in MCF-7 cells showed high biocompatibility of the synthesised nanofibres. The cytotoxicity assay results showed that the diagnostic nanofibres had excellent biocompatibility, indicating the feasibility for diagnosis purposes. With excellent contrast performance, the PEO-coated Er2O3 nanofibres developed novel T2 and T1-T2 dual-mode MRI diagnostic nanofibres leading to better cancer diagnosis. In conclusion, this work has demonstrated that the conjugation of PEO-coated Er2O3 nanofibres improved the surface modification of the Er2O3 nanoparticles as a potential diagnostic agent. Using PEO in this study as a carrier or polymer matrix significantly influenced the biocompatibility and internalisation efficiency of the Er2O3 nanoparticles without triggering any morphological changes after treatment. This work has suggested permissible concentrations of PEO-coated Er2O3 nanofibres for diagnostic uses.