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Highlights: [•] Cholesterol (CL) was incorporated into pH-sensitive polymersomes. [•] The CL incorporation enhanced colloidal stability of the polymersomes. [•] The CL incorporation did not damage on pH sensitivity of the polymersomes. [•] CL-incorporating polymersomes played a role as an intracellular drug carrier. [Copyright &y& Elsevier]

Despitethe numerous vital functions of proteins in the cytosoliccompartment, less attention has been paid to the delivery of proteindrugs to the cytosol than to the plasma membrane. To address thisissue and effectively deliver charged proteins into the cytoplasm,we used endosomolytic, thiol-triggered degradable polyelectrolytesas carriers. The cationic, reducible polyelectrolyte RPC-bPEI0.8 kDa2 was synthesized by the oxidative polymerizationof thiolated branched polyethyleneimine (bPEI). The polymer was convertedto the anionic, reducible polyelectrolyte RPA-bPEI0.8 kDa2 by introducing carboxylic acids. The two reducible polyelectrolytes(RPC-bPEI0.8 kDa2 and RPA-bPEI0.8 kDa2) were complexed with counter-charged model proteins (bovine serumalbumin (BSA) and lysozyme (LYZ)), forming polyelectrolyte/proteincomplexes of less than 200 nm in size at weight ratios (WR) of ≥1.The resultant complexes maintained a proton buffering capacity nearlyequivalent to that of the polyelectrolytes in the absence of proteincomplexation and were cytocompatible with MCF7 human breast carcinomacells. Under cytosol-mimicking thiol-rich conditions, RPC-bPEI0.8 kDa2/BSA and RPA-bPEI0.8 kDa2/LYZcomplexes increased significantly in size and released the loadedprotein, unlike the protein complexes with nonreducible polyelectrolytes(bPEI25 kDaand bPEI25 kDaCOOH). Thepolyelectrolyte/protein complexes showed cellular uptake similar tothat of the corresponding proteins alone, but the former allowed moreprotein to escape into the cytosol from endolysosomes than the latteras a result of the endosomolytic function of the polyelectrolytes.In addition, the proteins in the polyelectrolyte/protein complexeskept their intrinsic secondary structures. In conclusion, the resultsshow the potential of the designed endosomolytic, reducible polyelectrolytesfor the delivery of proteins to the cytosol. [ABSTRACT FROM AUTHOR]

Polyplex formation (complexation) and gene release fromthe polyplexes(decomplexation) are major events in polymeric gene delivery; however,the effect of the decomplexation rate on transfection has been rarelyinvestigated. This study employed mixed polymers of poly(L-lysine) (PLL: MW ∼7.4 kDa) and reducible PLL (RPLL) (MW ∼6.7kDa) to design decomplexation rate-controllable PLL100–xRPLLx/pDNA complexes(PRLxpolyplexes). The transfection efficiencyof a model gene (luciferase) in MCF7 and HEK293 cell lines increasedwith increasing x(RPLL content) in the PRLxpolyplexes until peaking at x=2.5 and 10, respectively, after which point transfection efficiencydeclined rapidly. In MCF7 cells, PRL2.5polyplex produced3 or 223 times higher gene expression than PLL or RPLL polyplexes,respectively. Similarly, the transfection efficiency of PRL10polyplex-transfected HEK293 cells was 3.8 or 67 times higher thanthat of PLL or RPLL polyplexes, respectively. The transfection resultswere not apparently related to the particle size, surface charge,complexation/compactness, cellular uptake, or cytotoxicity of thetested polyplexes. However, the decomplexation rate varied by RPLLcontent in the polyplexes, which in turn influenced the gene transfection.The nuclear localization of pDNA delivered by PRLxpolyplexes showed a similar trend to their transfection efficiencies.This study suggests that an optimum decomplexation rate may resultin high nuclear localization of pDNA and transfection. Understandingin decomplexation and intracellular localization of pDNA may helpdevelop more effective polyplexes. [ABSTRACT FROM AUTHOR]

Abstract: To deliver nucleic acids including plasmid DNA (pDNA) and short interfering RNA (siRNA), polymeric gene carriers equipped with various functionalities have been extensively investigated. The functionalities of these polymeric vectors have been designed to overcome various extracellular and intracellular hurdles that nucleic acids and their carriers encounter during their journey from injection site to intracellular target site. This review briefly introduces known extracellular and intracellular issues of nucleic acid delivery and their solution strategies. We examine significant yet overlooked factors affecting nucleic acid delivery (e.g., microenvironmental pH, polymer/siRNA complexation, and pharmaceutical formulation) and highlight our reported approaches to solve these problems. [Copyright &y& Elsevier]

Abstract: Poly(lactide-co-glycolide) (PLGA) has most often been employed for the controlled release of protein formulations because of its safety profile with non-toxic degradation products. Nevertheless, such formulations have been plagued by a local acidic microenvironment and protein–polymer interactions, which result in chemical and physical denaturation of loaded proteins and often unfavorable release profiles. This study investigated the pH change of inner PLGA microsphere (MS) using charged (PLGA)n-b-branched polyethyleneimine (bPEI) micelles. The designed micelles can be transformed into either micelle or reverse micelle (RM) depending on the solvent and RM can form microspheres. In addition, (PLGA)n-b-bPEI can be modified into (PLGA)n-b-(carboxylated bPEI) via carboxylation of the primary amines. Cationic micelle (CM) or anionic micelle (AM) was complexed with counter-charged proteins leading to nanosized particles (approximately 100nm). In the micelle/protein complexes, the micelles mostly maintained their proton buffering capacity, and consequently, prevented or delayed the typical decrease in pH caused by degradation of PLGA in aqueous solution. Reconstitutable micelle/protein complexes allowed for increased and fine-tuned protein loading (~20wt.% when using CM1 (CM prepared from PLGA36kDa-b-bPEI25kDa)/insulin complexes) in PLGA MS. In CM2 (CM prepared from (PLGA36kDa)2-b-bPEI25kDa)/insulin (4 of weight ratio (WR) of micelle to protein; WR4)-loaded PLGA MS, CM2 strongly prevented the micellar nanoenvironmental pH (pH 6.6 within 5days and then approximately pH 8.5) to be acidified in PLGA MS for 9weeks, unlike CM2-free PLGA MS. In conclusion, our findings propose that the proton buffering capacity and protein loading in PLGA MS can be tuned by controlling the complexation ratios of micelles and proteins, polymeric architectures of (PLGA)n-b-bPEI copolymers and WR of micelle/protein complexes and PLGA (or RM). [Copyright &y& Elsevier]

Abstract: Although polymers, polyplexes, and cells are exposed to various extracellular and intracellular pH environments during polyplex preparation and polymeric transfection, the impact of environmental pH on polymeric transfection has not yet been investigated. This study aims to understand the influence of environmental pH on polymeric transfection by modulating the pH of the transfection medium or the culture medium. Changes in the extracellular pH affected polymeric transfection by way of complex factors such as pH-induced changes in polymer characteristics (e.g., proton buffering capacity and ionization), polyplex characteristics (e.g., size, surface charge, and decomplexation), and cellular characteristics (e.g., cellular uptake, cell cycle phases, and intracellular pH environment). Notably, acidic medium delayed endocytosis, endosomal acidification, cytosolic release, and decomplexation of polyplexes, thereby negatively affecting gene expression. However, acidic medium inhibited mitosis and reduced dilution of gene expression, resulting in increased transfection efficiency. Compared to pH 7.4 medium, acidic transfection medium reduced gene expression 1.6–7.7-fold whereas acidic culture medium enhanced transfection efficiency 2.1–2.6-fold. Polymeric transfection was affected more by the culture medium than by the transfection medium. Understanding the effects of extracellular pH during polymeric transfection may stimulate new strategies for determining effective and safe polymeric gene carriers. [Copyright &y& Elsevier]

Abstract: This study investigated the potential of creating a charged polymeric micelle-based nucleic acid delivery system that could easily be reconstituted by the addition of water. (PLGA36kDa)2-b-bPEI25kDa (PLGA MW 36 kDa, bPEI Mw 25 kDa, PLGA:bPEI block ratio = 2) was synthesized and used to prepare cationic micelles. The copolymer retained proton-buffering capability from the bPEI block within the endosomal pH range. Micelle/pDNA complexes retained their particle size (100–150 nm) and surface charge (30–40 mV) following reconstitution. It was found that adding a small amount of low molecular weight bPEI (1.8 kDa) completely shielded pDNA in the micelle/pDNA complexes and enhanced transfection efficiency 50–100 fold for both fresh and reconstituted complexes without affecting complex size. Transfection efficiency for “reconstituted” micelle/pDNA/bPEI1.8kDa (WR 1) complexes was 16-fold higher than its “fresh” counterpart. Although transfection levels achieved using “reconstituted” micelle/pDNA/bPEI1.8kDa complexes were 3.6-fold lower than control “fresh” bPEI25kDa/pDNA (N/P 5) complexes, transfection levels were 39-fold higher than “reconstituted” bPEI25kDa/pDNA (N/P 5) complexes. The micelle/pDNA/bPEI1.8kDa system showed very low cytotoxicity in MCF7 cells even with pDNA doses up to 20 μg, and transfection levels increased linearly with increasing pDNA dose. These results indicate that this PLGA-b-bPEI polymeric micelle-based system is well suited as a reconstitutable gene delivery system, and has high potential for use as a delivery system for gene therapy applications. [Copyright &y& Elsevier]

Abstract: To improve transfection efficiency and reduce the cytotoxicity of polymeric gene vectors, reducible polycations (RPC) were synthesized from low molecular weight (MW) branched polyethyleneimine (bPEI) via thiolation and oxidation. RPC (RPC-bPEI0.8 kDa) possessed MW of 5 kDa–80 kDa, and 50%–70% of the original proton buffering capacity of bPEI0.8 kDa was preserved in the final product. The cytotoxicity of RPC-bPEI0.8 kDa was 8–19 times less than that of the gold standard of polymeric transfection reagents, bPEI25 kDa. Although bPEI0.8 kDa exhibited poor gene condensing capacities (∼2 μm at a weight ratio (WR) of 40), RPC-bPEI0.8 kDa effectively condensed plasmid DNA (pDNA) at a WR of 2. Moreover, RPC-bPEI0.8 kDa/pDNA (WR ≥2) formed 100–200 nm-sized particles with positively charged surfaces (20–35 mV). In addition, the results of the present study indicated that thiol/polyanions triggered the release of pDNA from RPC-bPEI0.8 kDa/pDNA via the fragmentation of RPC-bPEI0.8 kDa and ion-exchange. With negligible polyplex-mediated cytotoxicity, the transfection efficiencies of RPC-bPEI0.8 kDa/pDNA were approximately 1200–1500-fold greater than that of bPEI0.8 kDa/pDNA and were equivalent or superior (∼7-fold) to that of bPEI25 kDa/pDNA. Interestingly, the distribution of high MW RPC-bPEI0.8 kDa/pDNA in the nucleus of the cell was higher than that of low MW RPC-bPEI0.8 kDa/pDNA. Thus, the results of the present study suggest that RPC-bPEI0.8 kDa has the potential to effectively deliver genetic materials with lower levels of toxicity. [ABSTRACT FROM AUTHOR]

Abstract: While multidrug resistance (MDR) has been a significant issue in cancer chemotherapy, delivery resistance to various anti-cancer biotherapeutics, including genes, has not been widely recognized as a property of MDR. This study aims to provide a better understanding of the transfection characteristics of drug-sensitive and drug-resistant cells by tracing microenvironmental pHs of two representative polymer vectors: poly(l-lysine) and polyethyleneimine. Drug-sensitive breast MCF7 cells had four- to seven-times higher polymeric transfection efficiencies than their counterpart drug-resistant MCF7/ADR-RES cells. Polyplexes in MCF7/ADR-RES cells after endocytosis were exposed to a more acidic microenvironment than those in MCF7 cells; the MDR cells show faster acidification rates in endosomes/lysosomes than the drug-sensitive cells after endocytosis (in the case of PLL/pDNA complexes, ∼ pH 5.1 for MCF7/ADR-RES cells vs. ∼ pH 6.8 for MCF7 cells at 0.5 h post-transfection). More polyplexes were identified trapped in acidic subcellular compartments of MCF7/ADR-RES cells than in MCF7 cells, suggesting that they lack endosomal escaping activity. These findings demonstrate that the design of polymer-based gene delivery therapeutics should take into account the pH of subcellular compartments. [Copyright &y& Elsevier]

Abstract: The use of genetically modified islets is a potential strategy for overcoming pitfalls that currently plague islet transplantation. This study employed functional polymeric vectors specifically designed to transfect insulin-secreting cells and results were compared to various non-viral vectors. The evaluation included transfection efficiency, experimental condition effects, gross morphological observation, cytotoxicity, apoptosis, gene distribution in treated islets, insulin secretion function and time-dependent gene expression pattern. Observations from this study suggest that 1) the experimental conditions for islet transfection should be optimized, 2) the cytotoxicity of sulfonylurea containing vectors differs between the RINm5F cell line and primary pancreatic islets, 3) the non-viral vectors were primarily located in the peripheral region of an islet where the initial cell toxicity/apoptosis was apparent, 4) the genetic modification of pancreatic islets with genes for secretory proteins is more feasible than for residing proteins, and 5) the gene construct selection may prolong the gene expression period and oscillating pattern as demonstrated in this study. This study provides some fundamental background information that will aid in further designing polymeric gene vectors for the optimal manipulation of pancreatic islets prior to transplantation. [Copyright &y& Elsevier]

Abstract: Polyethyleneimine (PEI)-g-All-trans-retinoic acid (ATRA) (designated as PRA) was synthesized as a gene carrier. ATRA at its low concentration is known to be linked to nuclear translocation and cell cycle control (either proliferation or growth arrest) depending on its binding protein in cells. The cytotoxicity of PRA conjugates was lower than that of PEI and was gradually reduced as increasing ATRA graft ratios. The resulting nanosized and positively charged PRA/pDNA complexes showed lower transfection efficiency than the PEI/pDNA complexes (N/P=10) against NIH3T3 which is less sensitive to ATRA in cell growth and more sensitive HeLa cells. However, when a mixed gene complex of PEI and PRA was applied in an effort to reduce the ATRA contents, their NIH3T3 transfection evidenced effective nuclear translocation and induced 2- to 4-fold better transfection efficiency as compared with the PEI/pDNA complexes. When the PEI/pDNA complexes were utilized to transfect HeLa cells, free ATRA treatment reduced their cellular uptake and transfection efficiency. These findings show that the NIH3T3 cells against ATRA-mediated growth arrest would not damage the PRA-mediated transfection enhancement resulting from the facilitated nuclear translocation of polyplexes or pDNA. The more ATRA-sensitivity in growth arrest of HeLa cells would reduce the transfection efficiency of ATRA-incorporated polyplexes. The transfection capability of gene by newly synthesized PRA conjugates to cells is differentiated by their ATRA-sensitivity to nuclear translocation and cell growth control. [Copyright &y& Elsevier]

Abstract: Ex vivo transfer of therapeutic genes to cells is one of the potential strategies to prolong the life span of cell transplants. However, relatively safe non-viral carriers have not been extensively investigated due to their lower transfection efficiency. In this study, poly(l-lysine)-g-sulfonylurea varying SU content (PLL-SU) was synthesized to promote gene delivery efficacy to an insulin secreting cell line, RINm5F, which is known to express sulfonylurea receptor (SUR). The polymer formed complexes with a model reporter gene of pCMV-Luc (DNA) and the size of resulting particles was around 100 nm. The transfection efficiency of a polymer synthesized with 5 mol% of SU in the reaction feed (PLL-SU5%) to RINm5F cell was at least 5 times higher than that of PLL. The cytotoxicity of PLL-SU5%/DNA complex was equivalent to that of PLL/DNA complex. PLL-SU5% showed less transfection efficiency than PLL to NIH3T3 and HepG2 cells which are SUR negative. In RINm5F cells, the addition of free SU decreased the transfection efficiency of PLL-SU5%/DNA complex, suggesting that the complex shares the same receptors for SU. The PLL-SU5%/DNA complex seems to be internalized via SUR-mediated endocytosis pathway as suggested by vacuolar ATPases inhibition by Bafilomycin A1. It is noted that RINm5F cells treated with PLL-SU5%/DNA complex secreted more insulin than control, untreated cells, suggesting the insulinotropic effect of SU in PLL-SU5%. In conclusion, PLL-SU may be useful for transfer of therapeutic genes into insulin secreting cells. [Copyright &y& Elsevier]

Although previous studies have examined the signaling pathway involved in melanogenesis through which ultraviolet (UV) or α-melanocyte-stimulating hormones (α-MSH) stimuli act as key inducers to produce melanin at the stratum basal layer of the epidermis, the signaling pathway regulating melanogenesis is still controversial. This study reports that α-MSH, not UVA and UVB, acted as a major stimulus of melanogenesis in B16F10 melanoma cells. Signaling pathway analysis using gene knockdown technology and chemical inhibitors, the mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK)/p90 ribosomal S6 kinase 2 (RSK2) played an important role in melanogenesis. Unexpectedly, LY294002, a PI3K inhibitor, increased melanogenesis without UV or α-MSH stimulation, suggesting that the PI3K/AKT signaling pathway may not be a major signaling pathway for melanogenesis. Chemical inhibition of the MEKs/ERKs/RSK2 signaling pathway using U0126 or BI-D1870 suppressed melanogenesis by stimulation of UVA or α-MSH stimulation, or both. In particular, the genetic depletion of RSK2 or constitutive active (CA)-RSK2 overexpression showed that RSK2 plays a key role in melanogenesis. Interestingly, forkhead box protein O4 (FOXO4) was phosphorylated by RSK2, resulting in the increase of FOXO4’s transactivation activity. Notably, the FOXO4 mutant harboring serine-to-alanine replacement at the phosphorylation sites totally abrogated the transactivation activity and reduced melanin production, indicating that RSK2-mediated FOXO4 activity plays a key role in melanogenesis. Furthermore, kaempferol, a flavonoid inhibiting the RSK2 activity, suppressed melanogenesis. In addition, FOXO4-wt overexpression showed that FOXO4 enhance melanin synthesis. Overall, the RSK2-FOXO4 signaling pathway plays a key role in modulating melanogenesis. [ABSTRACT FROM AUTHOR]

Sonodynamic therapy (SDT) has emerged as an effective therapeutic modality as it employs ultrasound (US) to eradicate deep-seated tumors noninvasively. However, the therapeutic efficacy of SDT in clinical settings remains limited owing to the low aqueous stability and poor pharmacokinetic properties of sonosensitizers. In this study, extracellular vesicles (EVs), which have low systemic toxicity, were used as clinically available nanocarriers to effectively transfer a sonosensitizer to cancer cells. Chlorin e6 (Ce6), a sonosensitizer, was conjugated to a mitochondria-targeting triphenylphosphonium (TPP) moiety and loaded into EVs to enhance the efficacy of SDT, because mitochondria are critical subcellular organelles that regulate cell survival and death. Additionally, piperlongumine (PL), a pro-oxidant and cancer-specific chemotherapeutic agent, was co-encapsulated into EVs to achieve efficient and selective anticancer activity. The EVs substantially amplified the cellular internalization of TPP-conjugated Ce6 (TPP-Ce6), resulting in the enhanced generation of intracellular reactive oxygen species (ROS) in MCF-7 human breast cancer cells upon US exposure. Importantly, EVs encapsulating TPP-Ce6 effectively destroyed the mitochondria under irradiation with US, leading to efficient anticancer activity. The co-encapsulation of pro-oxidant PL into EVs significantly enhanced the SDT efficacy in MCF-7 cells through the excessive generation of ROS. Moreover, the EV co-encapsulating TPP-Ce6 and PL [EV(TPP-Ce6/PL)] exhibited cancer-specific cell death owing to the cancer-selective apoptosis triggered by PL. In vivo study using MCF-7 tumor-xenograft mice revealed that EV(TPP-Ce6/PL) effectively accumulated in tumors after intravenous injection. Notably, treatment with EV(TPP-Ce6/PL) and US inhibited tumor growth significantly without causing systemic toxicity. This study demonstrated the feasibility of using EV(TPP-Ce6/PL) for biocompatible and cancer-specific chemo-SDT. [Display omitted] [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) has emerged as an effective treatment for various solid tumors. The transcription factor NRF2 is known to protect against oxidative and electrophilic stress; however, its constitutive activity in cancer confers resistance to anti-cancer drugs. In the present study, we investigated NRF2 signaling as a potential molecular determinant of pheophorbide a (Pba)-based PDT by using NRF2-knockdown breast carcinoma MDA-MB-231 cells. Cells with stable NRF2 knockdown showed enhanced cytotoxicity and apoptotic/necrotic cell death following PDT along with increased levels of singlet oxygen and reactive oxygen species (ROS). A confocal microscopic visualization of fluorogenic Pba demonstrated that NRF2-knockdown cells accumulate more Pba than control cells. A subsequent analysis of the expression of membrane drug transporters showed that the basal expression of BCRP is NRF2-dependent. Among measured drug transporters, the basal expression of breast cancer resistance protein (BCRP; ABCG2) was only diminished by NRF2-knockdown. Furthermore, after incubation with the BCRP specific inhibitor, differential cellular Pba accumulation and ROS in two cell lines were abolished. In addition, NRF2-knockdown cells express low level of peroxiredoxin 3 compared to the control, which implies that diminished mitochondrial ROS defense system can be contributing to PDT sensitization. The role of the NRF2-BCRP pathway in Pba-PDT response was further confirmed in colon carcinoma HT29 cells. Specifically, NRF2 knockdown resulted in enhanced cell death and increased singlet oxygen and ROS levels following PDT through the diminished expression of BCRP. Similarly, PDT-induced ROS generation was substantially increased by treatment with NRF2 shRNA in breast carcinoma MCF-7 cells, colon carcinoma HCT116 cells, renal carcinoma A498 cells, and glioblastoma A172 cells. Taken together, these results indicate that the manipulation of NRF2 can enhance Pba-PDT sensitivity in multiple cancer cells. [ABSTRACT FROM AUTHOR]

The toxicokinetics of β-amanitin, a toxic bicyclic octapeptide present abundantly in Amanitaceae mushrooms, was evaluated in mice after intravenous (iv) and oral administration. The area under plasma concentration curves (AUC) following iv injection increased in proportion to doses of 0.2, 0.4, and 0.8 mg/kg. β-amanitin disappeared rapidly from plasma with a half-life of 18.3–33.6 min, and 52.3% of the iv dose was recovered as a parent form. After oral administration, the AUC again increased in proportion with doses of 2, 5, and 10 mg/kg. Absolute bioavailability was 7.3–9.4%, which resulted in 72.4% of fecal recovery from orally administered β-amanitin. Tissue-to-plasma AUC ratios of orally administered β-amanitin were the highest in the intestine and stomach. It also readily distributed to kidney > spleen > lung > liver ≈ heart. Distribution to intestines, kidneys, and the liver is in agreement with previously reported target organs after acute amatoxin poisoning. In addition, β-amanitin weakly or negligibly inhibited major cytochrome P450 and 5′-diphospho-glucuronosyltransferase activities in human liver microsomes and suppressed drug transport functions in mammalian cells that overexpress transporters, suggesting the remote drug interaction potentials caused by β-amanitin exposure. [ABSTRACT FROM AUTHOR]

Atopic dermatitis is a chronic inflammatory skin disease, of which incidence is closely related to exposure to environmental pollutants and allergens. Thymic stromal lymphopoietin (TSLP) plays an important role in the early stages of atopic dermatitis development by inducing Th2 immune responses. In addition, TSLP regulates activation of group 2 innate lymphoid cells (ILC2), promoting the pathogenesis of atopic dermatitis. The aim of this study was to investigate whether celastrol alleviated atopic dermatitis symptoms by regulating TSLP expression and ILC2 stimulation. Celastrol suppressed TSLP production in mouse keratinocyte cells by inhibiting NF-ĸB activation. Topical application of celastrol significantly improved atopic dermatitis symptoms induced by house dust mite (HDM) in NC/Nga mice as determined by dermatitis score and histological assessment. Celastrol decreased the levels of TSLP in atopic dermatitis skin lesions of HDM-stimulated NC/Nga mice. Celastrol reduced levels of Th2 cytokines including IL-4, IL-5, and IL-13 in atopic dermatitis skin lesions of NC/Nga mice. Further, celastrol significantly reduced ILC2 population in atopic dermatitis skin lesions of NC/Nga mice. These results indicate that topical application of celastrol improved atopic dermatitis symptoms by lowering TSLP levels and concomitant immune responses. Data demonstrated that reduced TSLP levels and associated lower number of ILC2 cells alleviate atopic dermatitis symptoms induced by house dust mite. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine pharmacokinetics of α-amanitin, a toxic bicyclic octapeptide isolated from the poisonous mushrooms, following intravenous (iv) or oral (po) administration in mice using a newly developed and validated liquid chromatography-high resolution mass spectrometry. The iv injected α-amanitin disappeared rapidly from the plasma with high a clearance rate (26.9–30.4 ml/min/kg) at 0.1, 0.2, or 0.4 mg/kg doses, which was consistent with a rapid and a major excretion of α-amanitin via the renal route (32.6%). After the po administration of α-amanitin at doses of 2, 5, or 10 mg/kg to mice, the absolute bioavailability of α-amanitin was 3.5–4.8%. Due to this low bioavailability, 72.5% of the po administered α-amanitin was recovered from the feces. When α-amanitin is administered po, the tissue to plasma area under the curve ratio was higher in stomach > large intestine > small intestine > lung ~ kidneys > liver but not detected in brain, heart, and spleen. The high distribution of α-amanitin to intestine, kidneys, and liver is in agreement with the previously reported major intoxicated organs following acute α-amanitin exposure. In addition, α-amanitin weakly or negligibly inhibited cytochrome P450 and 5′-diphospho-glucuronosyltransferase enzymes activity in human liver microsomes as well as major drug transport functions in mammalian cells overexpressing transporters. Data suggested remote drug interaction potential may be associated with α-amanitin exposure. [ABSTRACT FROM AUTHOR]

Abstract: For long-term, sustained protein delivery, a new, star-shaped block copolymer composed of methoxy poly(ethylene glycol) (mPEG), branched oligoethylenimine (bOEI), and poly(l-histidine) (pHis) was synthesized via the multi-initiation and ring-opening polymerization (ROP) of His N-carboxy anhydride (NCA) on bOEI with a PEG conjugation. The resulting mPEG-bOEI-pHis (POH) had strong buffering capacity within the neutral-to-acidic pH range and was complexed with insulin (Ins) via an electrostatic attraction plus hydrophobic interactions, resulting in the formation of a dual-interaction complex (DIC, weight ratio 2) of approximately 30–60 nm in size. This DIC tolerated high salt concentrations without destabilization, supporting the existence of hydrophobic interactions, and protected Ins from the organic solvent/water interface. The DIC in poly(lactide-co-glycolide) microspheres (PLGA MS) as a long-term Ins delivery formulation was evenly distributed via a double-emulsion method. The DIC-loaded PLGA MS offered a higher Ins loading and a lower initial burst than Ins-loaded PLGA MS. This formulation possessed near zero-order release kinetics (for at least one month). In streptozotocin (STZ)-induced diabetic rats, a DIC-loaded PLGA MS formulation was able to maintain blood-glucose levels at 200–350 mg/dL for the first two weeks and even lower levels (100–200 mg/dL) for the next two weeks. Thus, a new POH polymer and its complex with a drug protein could have potential biological application as a long-term, sustained protein delivery system. [Copyright &y& Elsevier]

Effective on‐demand release of therapeutics at an intracellular drug supply hub, the cytosol, is among the important steps for successful drug delivery. To improve cytosolic drug release, this study selects diselenide because the bond is cleaved by both glutathione (GSH) and reactive oxygen species (ROS) in the cytosol. Specifically, upon diselenide cleavage, the levels of GSH or ROS are reduced, resulting in decreased or increased cell viability and either the synergistic or antagonistic death of cancer cells with an anticancer drug, respectively, because GSH and ROS trigger two conflicting functions (i.e., antioxidant vs prooxidant activity). Thus, this study designs a diselenide‐based drug carrier to determine which trigger is the major cause of diselenide degradation, how the disrupted balance between GSH and ROS levels influences cell viability and drug efficacy, and whether the combined use of a diselenide drug carrier and a drug has a synergistic or antagonistic effect. Using a multiple diselenide‐containing nanoparticle (MSePCL‐NP), the study shows that diselenide is cleaved to a greater extent by GSH than by ROS; MSePCL‐NP induces a greater decrease in the viability of cancer cells, but not normal cells; a combination of DOX@MSePCL‐NP synergistically kills cancer cells and inhibits tumor growth in vivo. [ABSTRACT FROM AUTHOR]

Phalloidin, a bicyclic heptapeptide found in Amanita mushroom, specifically binds to F-actin in the liver causing cholestatic hepatotoxicity. However, the toxicokinetics and tissue distribution properties of phalloidin as well as their underlying mechanisms have to be studied further. The area under the plasma concentration curve (AUC) of phalloidin increased in proportion to the doses (0.2, 0.4, and 0.8 mg/kg for intravenous injection and 2, 5, and 10 mg/kg for oral administration). Phalloidin exhibited dose-independent low volume of distribution (395.6–456.9 mL/kg) and clearance (21.4–25.5 mL/min/kg) and low oral bioavailability (2.4%–3.3%). This could be supported with its low absorptive permeability (0.23 ± 0.05 × 10−6 cm/s) in Caco-2 cells. The tissue-to-plasma AUC ratios of intravenously injected and orally administered phalloidin were the highest in the liver and intestines, respectively, and also high in the kidneys, suggesting that the liver, kidneys, and intestines could be susceptible to phalloidin exposure and that active transport via the hepatic and renal organic anion transporters (OATP1B1, OATP1B3, and OAT3) may contribute to the higher distribution of phalloidin in the liver and kidneys. • LC-HRMS method was validated for quantification of phalloidin in mouse plasma. • Toxicokinetics and tissue distribution of phalloidin were characterized in mice. • Phalloidin is a substrate for OAT3, OATP1B1, and OATP1B3. • Phalloidin showed no inhibitory effects on human major CYP, UGT, and transporters. [ABSTRACT FROM AUTHOR]

Atopic dermatitis (AD) is a common and relapsing skin disease that is characterized by skin barrier dysfunction, inflammation, and chronic pruritus. While AD was previously thought to occur primarily in children, increasing evidence suggests that AD is more common in adults than previously assumed. Accumulating evidence from experimental, genetic, and clinical studies indicates that AD expression is a precondition for the later development of other atopic diseases, such as asthma, food allergies, and allergic rhinitis. Although the exact mechanisms of the disease pathogenesis remain unclear, it is evident that both cutaneous barrier dysfunction and immune dysregulation are critical etiologies of AD pathology. This review explores recent findings on AD and the possible underlying mechanisms involved in its pathogenesis, which is characterized by dysregulation of immunological and skin barrier integrity and function, supporting the idea that AD is a systemic disease. These findings provide further insights for therapeutic developments aiming to repair the skin barrier and decrease inflammation. [ABSTRACT FROM AUTHOR]

Abstract: DNA nanostructures have been widely studied in biomedical research contributing to targeted treatment of chronic diseases. The immunostimulatory XL‐DNA nanostructures of X‐shaped oligodeoxynucleotides complex are previously reported, activating toll‐like receptor9 in dendritic cells. This study examines whether the XL‐DNA could be therapeutically applied to treat immune diseases such as atopic dermatitis. To optimize topical delivery, liposome‐encapsulated XL‐DNA (Lipo‐XL‐DNA) is generated using emulsion transfer method with lipid layers composed of 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine, 1,2‐dioleoyl‐sn‐glycero‐3‐phospho‐(1′‐rac‐glycerol), and cholesterol. Size distribution of Lipo‐XL‐DNA ranges around 90–160 nm with mean diameter of 115.44 ± 18.72 nm. The morphology is confirmed by transmission electron microscope. Zeta potential is −28.59 mV. Confocal microscopy shows that Lipo‐XL‐DNA is efficiently delivered into epidermis and dermis. Topical application of Lipo‐XL‐DNA effectively alleviates atopic dermatitis symptoms in mice, as shown by dermatitis score, histological evaluation, and serum immunoglobulin E levels. RNA‐seq analysis confirms that Lipo‐XL‐DNA reduces pro‐inflammatory products, but increases epidermal barrier homeostasis factors in atopic dermatitis lesions. Lipo‐XL‐DNA orchestrates immune balance by downregulating Th2 immunity, but upregulating Th1 immunity. Collectively, liposome encapsulation enables efficient transdermal delivery of XL‐DNA, for an effective treatment of atopic dermatitis in mice. The results provide a promising therapeutic strategy using XL‐DNA nanostructures to treat immune‐compromised diseases. [ABSTRACT FROM AUTHOR]

The profiling of fatty acids (FAs) or sterols has been applied in clinical studies, but still needs to be improved to enable their simultaneous quantification. Moreover, little progress has been made in determining the levels of FAs and sterols in human saliva in a single run. In this study, gas chromatography-tandem mass spectrometry (GC–MS/MS) using one-step tert -butyldimethylsilyl (TBDMS) derivatization was developed for comprehensive profiling of 18 FAs (eight saturated, five monounsaturated, and five polyunsaturated FAs) and 7 sterols (cholesterol and its precursors). The TBDMS derivatization process was also optimized in terms of reaction solvent, catalyst, temperature, and reaction time. The optimized conditions resulted in better derivatization efficiency with good chromatographic separation through a high-temperature column within 23 min. The present method provided good linearity ( r  > 0.993), precision (coefficient of variation, 2.7% to 10.4%), and accuracy (91.5% to 103.4%). The overall recovery ranged from 73.8% to 114.3% for the 18 FAs, and from 68.9% to 79.8% for the 7 sterols. The validated method was applied to characterize FAs and sterols in human saliva samples. This is the first report of a GC–MS/MS method for the simultaneous determination of various FAs and sterols from a small volume (100 μL) of saliva. This approach can be used as a primary screening tool to examine the levels of both FAs and sterols in saliva, providing detailed information about their homeostasis for diagnostic and prognostic purposes. [ABSTRACT FROM AUTHOR]

Regnase-1 is an endoribonuclease that regulates the stability of target genes. Here, we investigated whether Regnase-1 plays a regulatory role in the pathophysiology of atopic dermatitis, a chronic inflammatory skin disease. Regnase-1 levels were decreased in skin and serum of atopic dermatitis patients and mice. Regnase-1 +/- mice exhibited more severe atopic dermatitis symptoms than wild-type mice in a house dust mite allergen-induced atopic dermatitis model. Regnase-1 deficiency led to the global changes in gene expression related with innate immune and inflammatory responses, in particular chemokines. The skin Regnase-1 level had an inverse relationship with chemokine expression when we analyzed samples of atopic dermatitis patients and Regnase-1-deficient mice, suggesting that potentiated chemokine production contributes to the augmented inflammation at lesion sites. Subcutaneous administration of recombinant Regnase-1 to mice significantly ameliorated atopic dermatitis-like skin inflammation with reduced chemokine production in a house dust mite-induced atopic dermatitis NC/Nga mouse model. These results indicate that Regnase-1 plays an essential role in maintaining skin immune homeostasis as a regulator of chemokine expression. Modulating Regnase-1 activity may be an efficient therapeutic strategy for treating chronic inflammatory diseases, including atopic dermatitis. [Display omitted] • Regnase-1 expression is decreased in skin and serum of atopic dermatitis patients. • Regnase-1 deficiency is linked to aggravated inflammation in atopic dermatitis. • Regnase-1 deficiency exacerbates chemokine expression in the lesional skin. • Recombinant Regnase-1 ameliorates atopic dermatitis symptoms and chemokine production. • Regnase-1 is an efficient therapeutic target for maintaining skin immune homeostasis. [ABSTRACT FROM AUTHOR]

We synthesized a new cationic AB 2 miktoarm block copolymer consisting of one poly (ethylene glycol) (PEG) block and two cationic poly ( l -lysine) (PLL) blocks, wherein the PLL blocks were conjugated to the PEG blocks with or without a bioreducible linker (disulfide bonds). Bioreducible and non-bioreducible miktoarm block copolymers (mPEG-(ss-PLL) 2 and mPEG-PLL 2 ) were prepared for efficient gene delivery as a non-viral gene delivery approach. Both cationic copolymers (bioreducible and nonbioreducible) efficiently formed the nanopolyplexes with plasmid DNA (pDNA) through electrostatic interaction at different weight ratio of polymer and pDNA. Gene condensation ability of the polymers and release of the DNA under reduction condition were measured by gel electrophoresis. Dynamic light scattering (DLS) and field-emission transmission electron microscopy (FE-TEM) were used to measure the average hydrodynamic diameter and morphology of the nanoparticles, respectively. The bioreducible nanopolyplexes showed lower cytotoxicity and higher gene expression than the non-reducible nanopolyplexes in cancer cells. [ABSTRACT FROM AUTHOR]

Objective. The aetiology of gout is closely linked to the deposition of monosodium uric acid (MSU) crystals and the consequent activation of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome. In this study, we investigated whether oral administration of an NLRP3 inhibitor would be effective to attenuate the symptoms of gout. Methods. The effects of oral administration with sulforaphane (SFN) were examined in two mouse models of acute gout induced by injection of MSU crystals into footpads or air pouch. The production of caspase- 1 (p10) and IL-1β was examined by immunoblotting and ELISA as hallmarks of NLRP3 inflammasome activation. Results. Oral administration of SFN attenuated MSU crystal-induced swelling and neutrophil recruitment in a mouse foot acute gout model, correlating with the suppression of the NLRP3 inflammasome activation in foot tissues. Consistently, oral administration of SFN blocked MSU-crystal-induced activation of the NLRP3 inflammasome in a mouse air pouch gout model. SFN suppressed NLRP3 inflammasome activation induced by MSU crystals, adenosine triphosphate and nigericin but not by poly(dA:dT) in primary mouse macrophages, independent of the reactive oxygen species pathway. SFN inhibited ligand-independent activation of the NLRP3 inflammasome, suggesting that SFN may act directly on the NLRP3 inflammasome complex. Conclusion. Oral administration of SFN effectively alleviated acute gouty inflammation by suppression of the NLRP3 inflammasome. Our results provide a novel strategy in which oral treatment with SFN may be beneficial in preventing acute attacks of gout. [ABSTRACT FROM AUTHOR]

Mesoporous silica nanoparticles (MSN) have several advantages as carriers for drug delivery, including high drug loading capacity, good biocompatibility, excellent stability, and easily tailorable surface properties. This study describes the design of an MSN-based carrier for use in a heat shock responsive drug delivery system. MSN were functionalized with the temperature-sensitive PEG/PCL multiblock copolymer, as gatekeepers, allowing the release of entrapped drugs in response to heat shock stimuli (MBC-MSN). In the absence of heat shock, doxorubicin (Dox)-loaded MBC-MSN showed very low cytotoxicity, as PEG/PCL inhibited the premature release of Dox from MBC-MSN. In response to heat-shock stimuli, however, these Dox@MBC-MSN showed significant cytotoxicity, similar to that of free Dox. Dox release was due to the loosening of the structure of the gatekeeper, PEG/PCL, in response to the heat shock stimuli. Taken together, these findings suggest that MBC-MSN are a strong candidate to act as a carrier in heat shock responsive drug delivery. [ABSTRACT FROM AUTHOR]

Hydrophobicity modulates both the nucleus-to-mitochondria targeting switch and slow disulfide cleavage, resulting in mitochondria-targeted delivery of DOX@REPL-NG and release of DOX from DOX@REPL-NG. [Display omitted] • A new nanogel delivers and releases hydrophobic payloads to mitochondria targets. • Hydrophobicity modulates both the switching of organelle targeting and slow disulfide cleavage. • Hydrophobic lysines preferentially select mitochondria. • Hydrophobic neighbors cause glutathione to slowly cleave the disulfide for slow drug release. Despite the significance of organelle-targeted delivery and the subsequent release of therapeutics, the therapeutic outcome of this technology is limited due to undesired organelle targeting and unwanted cytosolic drug release. In this study, an ε-poly(l -lysine) (EPL)-based bioreducible nanogel (REPL-NG) was designed to deliver and release hydrophobic payloads to mitochondria targets, and the NG was synthesized via a sequential thiolation and oxidation reaction. REPL-NG contains a hydrophilic NG surface, which provides colloidal stability in aqueous environments due to the ionizable amine in lysine. Hydrophobic chemicals were encapsulated as a result of the multiple disulfide-mediated and crosslinked inner compartments. The capability of the ionizable amines to buffer protons helped the NG escape endolysosomes. The neighboring hydrophobic lysine preferentially drove the NG into mitochondria rather than the nucleus, and the neighboring hydrophobic disulfide bonds were slowly cleaved by the intracellularly reduced glutathione (GSH) in mitochondria. In an HCT116 xenograft tumor-bearing mouse model, doxorubicin (DOX)-loaded REPL-NG (DOX@REPL-NG) resulted in better blood circulation, better tumor accumulation and retention, and ultimately more effective inhibition of tumor growth than free drugs. In conclusion, hydrophobicity could modulate both the nucleus-to-mitochondria targeting switch and slow disulfide cleavage, resulting in mitochondria-targeted delivery of DOX@REPL-NG and release of DOX from DOX@REPL-NG. [ABSTRACT FROM AUTHOR]

Mitochondria-targeting drug carriers have considerable potential because of the presence of many molecular drug targets in the mitochondria and their pivotal roles in cellular viability, metabolism, maintenance, and death. To compare the mitochondria-targeting abilities of triphenylphosphonium (TPP) and pheophorbide a (PhA) in nanoparticles (NPs), this study prepared mitochondria-targeting NPs using mixtures of methoxy poly(ethylene glycol)-(SS-PhA) 2 [mPEG-(SS-PhA) 2 or PPA] and TPP- b -poly(ε-caprolactone)- b -TPP [TPP- b -PCL- b -TPP or TPCL], which were designated PPA n -TPCL 4-n (0 ≤ n ≤ 4) NPs. With increasing TPCL content, the formed PPA n -TPCL 4-n NPs decreased in size from 33 nm to 18 nm and increased in terms of positive zeta-potentials from −12 mV to 33 mV. Although the increased TPCL content caused some dark toxicity of the PPA n -TPCL 4-n NPs due to the intrinsic positive character of TPCL, the NPs showed strong light-induced killing effects in tumor cells. In addition, the mitochondrial distribution of the PPA n -TPCL 4-n NPs was analyzed and imaged by flow cytometry and confocal microscopy, respectively. Thus, the PhA-containing NPs specifically targeted the mitochondria, and light stimulation caused PhA-mediated therapeutic effects and imaging functions. Expanding the capabilities of these nanocarriers by incorporating other drugs should enable multiple potential applications (e.g., targeting, therapy, and imaging) for combination and synergistic treatments. [ABSTRACT FROM AUTHOR]

Nucleotides (NTs), such as adenosine triphosphate (ATP) and guanosine triphosphate (GTP), are signaling and bioenergy molecules to mediate a range of cellular pathways. We recently reported their significant endosomolytic activity. To evaluate whether polymeric NTs keep endosomolytic and bioenergetic functions of NTs in drug delivery and cell survival, NTs were polymerized by a coupling reaction to form polynucleotides (pNTs: pATP and pGTP) with their molecular weights around 500 kDa. The cellular toxicity, indicated by IC 50 , of pNT was as low as that of corresponding monomeric NT. pNTs were degraded by an intracellular enzyme, alkaline phosphatase. Introduction of pNTs in a polycation-gene complex (polyplex) enhanced the extent of gene expression in cancerous, non-cancerous, and stem cells, up to 1500-fold higher than that of pNT-free polyplex. In addition, cells stored in a pATP solution resulted in a significantly higher survival rate (e.g., up to 20% increase) when exposed to low temperatures than pATP-free solution. The presence of pNT in polyplexes prevented the reduction of transfection efficiency induced by a low temperature. The findings in this study suggest that endosomolytic and bioenergetic pNTs serve as a non-toxic gene carrier component and protect cells from a cold shock or energy depletion. [ABSTRACT FROM AUTHOR]

For mitochondria-targeting delivery, a coupling reaction between poly(ε-caprolactone) diol (PCL diol) and 4-carboxybutyltriphenylphosphonium (4-carboxybutyl TPP) results in the synthesis of amphiphilic TPP-PCL-TPP (TPCL) polymers with a bola-like structure. In aqueous environments, the TPCL polymer self-assembled via cosolvent dispersion and film hydration, resulting in the formation of cationic nanoparticles (NPs) less than 50 nm in size with zeta-potentials of approximately 40 mV. Interestingly, different preparation methods for TPCL NPs result in various morphologies such as nanovesicles, nanofibers, and nanosheets. In vitro cytotoxicity results with TPCL NPs indicate IC50 values of approximately 10-60 μg mL−1, suggesting their potential as anticancer nanodrugs. TPCL NPs can be loaded both with hydrophobic doxorubicin (Dox) and its hydrophilic salt form (Dox·HCl), and their drug loading contents are approximately 2-10 wt% depending on the loading method and the hydrophilicity/hydrophobicity of the drugs. Although Dox·HCl exhibits more cellular and nuclear uptake, resulting in greater antitumor effects than Dox, most drug-loaded TPCL NPs exhibit higher mitochondrial uptake and approximately 2-7-fold higher mitochondria-to-nucleus preference than free drugs, resulting in superior (approximately 7.5-18-fold) tumor-killing activity for most drug-loaded TPCL NPs compared with free drugs. In conclusion, TPCL-based nanoparticles have potential both as antitumor nanodrugs themselves and as nanocarriers for chemical therapeutics. [ABSTRACT FROM AUTHOR]

A polyelectrolyte nanocomplex was prepared via the ionic interaction between the anionic heparin-pheophorbide a (HPhA) conjugate, which served as a water-soluble polysaccharide photosensitizer (PS), and the cationic polyethylenimine (PEI)-β-carotene (PCAR) conjugate, which served as a polymeric scavenger. This nanocomplex was designed to improve the water solubility and tumor specificity of PhA and to only release singlet oxygen at the tumor cell. A stable 150 nm-sized nanocomplex could be formed in the weight ratio range (PCAR/HPhA) of 0.3–0.5 in an aqueous environment. The PCAR scavenger significantly diminished the generation of active singlet oxygen from HPhA in a buffer solution. Singlet oxygen scavenging activity was lost only when HPhA and PCAR were separated from each other due to the dissociation of the complex nanostructures. It was confirmed that HPhA itself has neither colloidal properties nor a decrease in its ability to produce singlet oxygen. At the same time, the HPhA/PEI complex produced singlet oxygen in response to light. In a cell culture system, the cytotoxicity of the HPhA/PCAR nanocomplex toward cancer cells was greatly enhanced due to the efficient generation of singlet oxygen under light irradiation; this finding implies that the scavenging activity of PCAR can be restricted to intracellular environments. These results suggest that the HPhA/PCAR nanocomplex could provide a new activatable PS platform that facilitates more accurate and reliable photodynamic therapy (PDT) with site-specific and controllable production of singlet oxygen to be used for the treatment of cancer. [ABSTRACT FROM AUTHOR]

Abstract: Poly(ethylene glycol)-b-poly(caprolactone) (PEG-b-PCL) micelles dually loaded with both pheophorbide a (PhA) as a photosensitizer and β-carotene (CAR) as a singlet oxygen (1O2) scavenger were designed to control photodynamic therapy (PDT) activity in cancer treatment. The CAR in the PhA/CAR micelles significantly diminished PhA-generated 1O2 through direct 1O2 scavenging, whereas the CAR molecules lost their 1O2 scavenging activity when the PhA and CAR were spatially isolated by the disintegration of the PEG-b-PCL micelles. In cell-culture systems, light irradiation at a post-treatment time that corresponded to the presence of the micelles in the blood environment induced negligible phototoxicity, whereas light irradiation at a post-treatment time that corresponded to the presence of the micelles in the intracellular environment induced remarkable phototoxicity. In addition, a longer post-treatment time induced greater internalization of PhA/CAR micelles, which resulted in higher phototoxicity, suggesting an increase in photo killing activity against the tumor cells of interest. Thus, the co-loading of a 1O2 generator and a 1O2 scavenger into a single micelle is a potential strategy that may be useful in facilitating more accurate and reliable PDT with site-specific controllable production of singlet oxygen species for cancer treatment. [Copyright &y& Elsevier]

In the study presented here, we developeda bioreducible biarmedmethoxy poly(ethylene glycol)-(pheophorbide a)2(mPEG-(ss-PhA)2) conjugate for cancer-cell-specific photodynamic therapy(PDT). PhA molecules were chemically conjugated with biarmed linkagesat one end of the mPEG molecule via disulfide bonds. Under aqueousconditions, the amphiphilic mPEG-(ss-PhA)2conjugate self-assembledto form core–shell-structured nanoparticles (NPs) with goodcolloidal stability. The mPEG-(ss-PhA)2NPs exhibited intramolecularand intermolecular self-quenching effects that enabled the NPs toremain photoinactive in a physiological buffer. However, the dissociationof the NP structure was effectively induced by the cleavage of thedisulfide bonds in response to intracellular reductive conditions,triggering the rapid release of PhA molecules in a photoactive form.In cell-culture systems, in addition to significant phototoxicityand intracellular uptake, we observed that the dequenching processesof PhA in the mPEG-(ss-PhA)2NPs highly depended on theexpression of intracellular thiols and that supplementation with glutathionemonoethylester facilitated more rapid PhA release and enhanced thePhA phototoxicity. These findings suggest that the bioreducible activationmechanism of mPEG-(ss-PhA)2NPs in cancer cells can maximizethe cytosolic dose of active photosensitizers to achieve high cytotoxicity,thereby enhancing the treatment efficacy of photodynamic cancer treatment. [ABSTRACT FROM AUTHOR]

Due to increasing safety and intracellular delivery concerns about hydrophilic polymers in amphiphilic polymer-based nanoparticles (NPs), this study investigates small hydrophilic molecule-stabilized NPs for effective intracellular delivery with multiorganelle targetability and dual responsiveness to acidic pH/glutathione (GSH). In the construction of small hydrophilic molecule-stabilized NP (MSPCL-NP), the A-B-A-type amphiphilic polymer (MSPCL-P) is composed of two short hydrophilic carboxylate-capped disulfide derivatives (A) that replace hydrophilic polymers and assist in providing colloidal stability and preventing antibody (e.g., at least anti-PEG antibody)-mediated specific interactions and complement activation in the plasma and a hydrophobic multiple disulfide-containing poly(ε-caprolactone) block (B) that carries hydrophobic drugs. The carboxylates on the surface of MSPCL-NP target the acidic extratumoral/endolysosomal milieu by sensing and buffering acidic pH values, and the hydrophobic carboxylic acids improve adsorptive endocytosis and effective endosomal escape. Multiple disulfide linkages selectively target cytosolic GSH, resulting in rapid drug release from the destroyed MSPCL-NP via the cleavage of disulfide bonds in MSPCL-P. Doxorubicin (DOX)-loaded NP (DOX@MSPCL-NP) exerts strong effects on killing cells in vitro and inhibits tumor growth in HCT116 xenograft tumor-bearing mice. In conclusion, the multifunctionality and multispatial targetability of MSPCL-NP might effectively overcome various sequential drug delivery hurdles, ranging from blood circulation to drug release. Furthermore, the introduction of small hydrophilic molecules represents a potential strategy to make self-assembled NPs without the use of hydrophilic polymers. [ABSTRACT FROM AUTHOR]

Inflammation and immunity are linked to the onset and development of obesity and metabolic disorders. Pattern recognition receptors (PRRs) are key regulators of inflammation and immunity in response to infection and stress, and they have critical roles in metainflammation. In this study, we investigated whether RIG-I (retinoic acid-inducible gene I)-like receptors were involved in the regulation of obesity-induced metabolic stress in RIG-I knockout (KO) mice fed a high-fat diet (HFD). RIG-I KO mice fed an HFD for 12 weeks showed greater body weight gain, higher fat composition, lower lean body mass, and higher epididymal white adipose tissue (eWAT) weight than WT mice fed HFD. In contrast, body weight gain, fat, and lean mass compositions, and eWAT weight of MDA5 (melanoma differentiation-associated protein 5) KO mice fed HFD were similar to those of WT mice fed a normal diet. RIG-I KO mice fed HFD exhibited more severely impaired glucose tolerance and higher HOMA-IR values than WT mice fed HFD. IFN-β expression induced by ER stress inducers, tunicamycin and thapsigargin, was abolished in RIG-I-deficient hepatocytes and macrophages, showing that RIG-I is required for ER stress-induced IFN-β expression. Our results show that RIG-I deficiency promotes obesity and insulin resistance induced by a high-fat diet, presenting a novel role of RIG-I in the development of obesity and metabolic disorders. [ABSTRACT FROM AUTHOR]

A simple, robust, and rapid LC-MS/MS method has been developed and validated for the simultaneous quantitation of clopidogrel and its active metabolite (AM) in human plasma. Tris(2-carboxyethyl)phosphine (TCEP) was used as a reducing agent to detect the AM as a disulfide-bonded complex with plasma proteins. Mixtures of TCEP and human plasma were deproteinized with acetonitrile containing 10 ng/mL of clopidogrel-d4 as an internal standard (IS). The mixtures were separated on a C18 RP column with an isocratic mobile phase consisting of 0.1% formic acid in acetonitrile and water (90:10, v/v) at a flow rate of 0.3 mL/min. Detection and quantification were performed using ESI-MS. The detector was operated in selected reaction-monitoring mode at m/z 322.0→211.9 for clopidogrel, m/z 356.1→155.2 for the AM, and m/z 326.0→216.0 for the IS. The linear dynamic range for clopidogrel and its AM were 0.05-20 and 0.5-200 ng/mL, respectively, with correlation coefficients ( r) greater than 0.9976. Precision, both intra- and interday, was less than 8.26% with an accuracy of 87.6-106%. The validated method was successfully applied to simultaneously analyze clinical samples for clopidogrel and its AM. [ABSTRACT FROM AUTHOR]

Oxidized phospholipids are well known to play physiological and pathological roles in regulating cellular homeostasis and disease progression. However, their role in cancer metastasis has not been entirely understood. In this study, effects of oxidized phosphatidylcholines such as 1-palmitoyl-2-(5-oxovaleroyl)-sn-glycero-3-phosphocholine (POVPC) on epithelial-mesenchymal transition (EMT) and autophagy were determined in cancer cells by immunoblotting and confocal analysis. Metastasis was analyzed by a scratch wound assay and a transwell migration/invasion assay. The concentrations of POVPC and 1-palmitoyl-2-glutaroyl-sn-glycero-phosphocholine (PGPC) in tumor tissues obtained from patients were measured by LC-MS/MS analysis. POVPC induced EMT, resulting in increase of migration and invasion of human hepatocellular carcinoma cells (HepG2) and human breast cancer cells (MCF7). POVPC induced autophagic flux through AMPK-mTOR pathway. Pharmacological inhibition or siRNA knockdown of autophagy decreased migration and invasion of POVPC-treated HepG2 and MCF7 cells. POVPC and PGPC levels were greatly increased at stage II of patient-derived intrahepatic cholangiocarcinoma tissues. PGPC levels were higher in malignant breast tumor tissues than in adjacent nontumor tissues. The results show that oxidized phosphatidylcholines increase metastatic potential of cancer cells by promoting EMT, mediated through autophagy. These suggest the positive regulatory role of oxidized phospholipids accumulated in tumor microenvironment in the regulation of tumorigenesis and metastasis. [ABSTRACT FROM AUTHOR]

Gout is a type of inflammatory arthritis caused by the deposition of monosodium uric acid (MSU) crystals in tissues. The etiology of gout is directly linked to the NLRP3 inflammasome, since MSU crystals are NLRP3 inflammasome activators. Therefore, we decided to search for a small-molecule inhibitor of the NLRP3 inflammasome for the prevention of gout inflammation. We found that loganin suppressed MSU crystals-induced caspase-1 (p20) and interleukin (IL)-1β production and apoptosis-associated speck-like protein containing a caspase recruitment domain (ASC) specks formation in mouse primary macrophages, showing its ability to inhibit the NLRP3 inflammasome. In an air pouch inflammation model, oral administration of loganin to mice prevented MSU crystals-induced production of mature IL-1β and IL-18 in air pouch exudates, resulting in decreased neutrophil recruitment. Furthermore, oral administration of loganin suppressed MSU crystals-induced gout inflammation in a mouse foot gout model, which was accompanied by the inhibition of the NLRP3 inflammasome. Loganin blocked de novo synthesis of mitochondrial DNA in air pouches and foot tissues injected with MSU crystals. Consistently, loganin prevented MSU crystals-induced mitochondrial damage in macrophages, as it increased mitochondrial membrane potential and decreased the amount of mitochondrial reactive oxygen species. These data demonstrate that loganin suppresses NLRP3 inflammasome activation by inhibiting mitochondrial stress. These results suggest a novel pharmacological strategy to prevent gout inflammation by blocking NLRP3 inflammasome activation and mitochondrial dysfunction. [ABSTRACT FROM AUTHOR]

Although the lignan compound fargesin is a major ingredient in Shin-Yi, the roles of fargesin in carcinogenesis and cancer cell growth have not been elucidated. In this study, we observed that fargesin inhibited cell proliferation and transformation by suppression of epidermal growth factor (EGF)-stimulated G1/S-phase cell cycle transition in premalignant JB6 Cl41 and HaCaT cells. Unexpectedly, we found that signaling pathway analyses showed different regulation patterns in which fargesin inhibited phosphatidylinositol 3-kinase/AKT signaling without an alteration of or increase in mitogen activated protein kinase (MAPK) in JB6 Cl41 and HaCaT cells, while both signaling pathways were abrogated by fargesin treatment in colon cancer cells. We further found that fargesin-induced colony growth inhibition of colon cancer cells was mediated by suppression of the cyclin dependent kinase 2 (CDK2)/cyclin E signaling axis by upregulation of p21WAF1/Cip1, resulting in G1-phase cell cycle accumulation in a dose-dependent manner. Simultaneously, the suppression of CDK2/cyclin E and induction of p21WAF1/Cip1 were correlated with Rb phosphorylation and c-Myc suppression. Taken together, we conclude that fargesin-mediated c-Myc suppression inhibits EGF-induced cell transformation and colon cancer cell colony growth by the suppression of retinoblastoma (Rb)-E2F and CDK/cyclin signaling pathways, which are mainly regulated by MAPK and PKB signaling pathways. [ABSTRACT FROM AUTHOR]

Eudesmin, fargesin, epimagnolin A, magnolin, and yangambin are tetrahydrofurofuranoid lignans with various pharmacological activities found in Magnoliae Flos. The inhibition potencies of eudesmin, fargesin, epimagnolin A, magnolin, and yangambin on six major human uridine 5′-diphospho-glucuronosyltransferase (UGT) activities in human liver microsomes were evaluated using liquid chromatography–tandem mass spectrometry and cocktail substrates. Eudesmin, fargesin, epimagnolin A, magnolin, and yangambin inhibited UGT1A1 and UGT1A3 activities, but showed negligible inhibition of UGT1A4, UGT16, UGT1A9, and UGT2B7 activities at 200 μM in pooled human liver microsomes. Moreover, eudesmin, fargesin, epimagnolin A, magnolin, and yangambin noncompetitively inhibited UGT1A1-catalyzed SN38 glucuronidation with Ki values of 25.7, 25.3, 3.6, 26.0, and 17.1 μM, respectively, based on kinetic analysis of UGT1A1 inhibition in pooled human liver microsomes. Conversely, the aforementioned tetrahydrofurofuranoid lignans competitively inhibited UGT1A3-catalyzed chenodeoxycholic acid 24-acyl-glucuronidation with 39.8, 24.3, 15.1, 37.6, and 66.8 μM, respectively in pooled human liver microsomes. These in vitro results suggest the necessity of evaluating whether the five tetrahydrofurofuranoid lignans can cause drug–drug interactions with UGT1A1 and UGT1A3 substrates in vivo. [ABSTRACT FROM AUTHOR]

Indazole carboxamide synthetic cannabinoid, AB-PINACA, has been placed into Schedule I of the Controlled Substances Act by the US Drug Enforcement Administration since 2015. Despite the possibility of AB-PINACA exposure in drug abusers, the interactions between AB-PINACA and drug-metabolizing enzymes and transporters that play crucial roles in the pharmacokinetics and efficacy of various substrate drugs have not been investigated. This study was performed to investigate the inhibitory effects of AB-PINACA on eight clinically important human major cytochrome P450s (CYPs) and six uridine 5′-diphospho-glucuronosyltransferases (UGT) in human liver microsomes and the activities of six solute carrier transporters and two efflux transporters in transporter-overexpressing cells. AB-PINACA reversibly inhibited the metabolic activities of CYP2C8 (Ki, 16.9 µM), CYP2C9 (Ki, 6.7 µM), and CYP2C19 (Ki, 16.1 µM) and the transport activity of OAT3 (Ki, 8.3 µM). It exhibited time-dependent inhibition on CYP3A4 (Ki, 17.6 µM; kinact, 0.04047 min−1). Other metabolizing enzymes and transporters such as CYP1A2, CYP2A6, CYP2B6, CYP2D6, UGT1A1, UGT1A3, UGT1A4, UGT1A6, UGT1A9, UGT2B7, OAT1, OATP1B1, OATP1B3, OCT1, OCT2, P-glycoprotein, and BCRP, exhibited only weak interactions with AB-PINACA. These data suggest that AB-PINACA can cause drug-drug interactions with CYP3A4 substrates but that the significance of drug interactions between AB-PINACA and CYP2C8, CYP2C9, CYP2C19, or OAT3 substrates should be interpreted carefully. [ABSTRACT FROM AUTHOR]

Mitochondria are considered one of the most important subcellular organelles for targeting and delivering drugs because mitochondria are the main location for various cellular functions and energy (i.e., ATP) production, and mitochondrial dysfunctions and malfunctions cause diverse diseases such as neurodegenerative disorders, cardiovascular disorders, metabolic disorders, and cancers. In particular, unique mitochondrial characteristics (e.g., negatively polarized membrane potential, alkaline pH, high reactive oxygen species level, high glutathione level, high temperature, and paradoxical mitochondrial dynamics) in pathological cancers have been used as targets, signals, triggers, or driving forces for specific sensing/diagnosing/imaging of characteristic changes in mitochondria, targeted drug delivery on mitochondria, targeted drug delivery/accumulation into mitochondria, or stimuli-triggered drug release in mitochondria. In this review, we describe the distinctive structures, functions, and physiological properties of cancer mitochondria and discuss recent technologies of mitochondria-specific "key characteristic" sensing systems, mitochondria-targeted "drug delivery" systems, and mitochondrial stimuli-specific "drug release" systems as well as their strengths and weaknesses. • Mitochondria, which regulate cellular metabolism, are a pivotal target of drugs. • Cancer mitochondria have unique properties of MMP, pH, ROS, GSH, O 2 , and temperature. • Lipophilic cations deliver drugs into mitochondria by a negatively polarized MMP. • Mitochondria-targeting moieties guide drugs to accumulate in mitochondria. [ABSTRACT FROM AUTHOR]

The tight binding of pDNA with a cationic polymer is the crucial requirement that prevents DNA degradation from undesired DNase attack to safely deliver the pDNA to its target site. However, cationic polymer-mediated strong gene holding limits pDNA dissociation from the gene complex, resulting in a reduction in transfection efficiency. In this study, to control the decomplexation rate of pDNA from the gene complex in a hard-to-transfect cell or an easy-to-transfect cell, either α-poly(l-lysine) (APL) or ε-poly(l-lysine) (EPL) was incorporated into branched polyethylenimine (bPEI)-based nanocomplexes (NCs). Compared to bPEI/pDNA NCs, the addition of APL or EPL formed smaller bPEI-APL/pDNA NCs with similar zeta potentials or larger bPEI-EPL/pDNA NCs with reduced zeta potentials, respectively, due to the different characteristics of the primary amines in the two poly(l-lysine)s (PLs). Interestingly, although both bPEI-APL/pDNA NCs and bPEI-EPL/pDNA NCs showed similar pDNA compactness to bPEI/pDNA NCs, the addition of APL or EPL resulted in slower or faster pDNA release, respectively, from the bPEI-PL/pDNA NCs than from the bPEI/pDNA NCs. bPEI-EPL/pDNA NCs with a decomplexation enhancer (i.e., EPL) improved the transfection efficiency (TE) in both a hard-to-transfect HepG2 cell and an easy-to-transfect HEK293 cell. However, although a decomplexation inhibitor (i.e., APL) reduced the TE of bPEI-APL/pDNA NCs in both cells, the degree of reduction in the TE could be compensated by PL-mediated enhanced nuclear delivery, particularly in HepG2 cells but not HEK293 cells, because both PLs facilitate nuclear localization of the gene complex per its cellular uptake. In conclusion, a decomplexation rate controller could be a potential factor to establish a high TE and design clinically available gene complex systems. [ABSTRACT FROM AUTHOR]

Non-alcoholic steatohepatitis (NASH), a type of non-alcoholic fatty liver disease, is characterized as steatosis and inflammation in the liver. NLRP3 inflammasome activation is associated with NASH pathology. We hypothesized that suppressing the NLRP3 inflammasome could be effective in preventing NASH. We searched substances that could inhibit the activation of the NLRP3 inflammasome and identified sweroside as an NLRP3 inhibitor. We investigated whether sweroside can be applied to prevent the pathological symptoms associated with NASH in a methionine–choline-deficient (MCD) diet-induced NASH mouse model. The activation of the NLRP3 inflammasome was determined by detecting the production of caspase-1 and IL-1β from pro-caspase-1 and pro-IL-1β in primary mouse macrophages and mouse liver. In a NASH model, mice were fed an MCD diet for two weeks with daily intraperitoneal injections of sweroside. Sweroside effectively inhibited NLRP3 inflammasome activation in primary macrophages as shown by a decrease in IL-1β and caspase-1 production. In a MCD diet-induced NASH mouse model, intraperitoneal injection of sweroside significantly reduced serum aspartate transaminase and alanine transaminase levels, hepatic immune cell infiltration, hepatic triglyceride accumulation, and liver fibrosis. The improvement of NASH symptoms by sweroside was accompanied with its inhibitory effects on the hepatic NLRP3 inflammasome as hepatic IL-1β and caspase-1 were decreased. Furthermore, sweroside blocked de novo synthesis of mitochondrial DNA in the liver, contributing to suppression of the NLRP3 inflammasome. These results suggest that targeting the NLRP3 inflammasome with sweroside could be beneficially employed to improve NASH symptoms. [ABSTRACT FROM AUTHOR]

Doxorubicin, an anthracycline antitumor antibiotic, acts as a cancer treatment by interfering with the function of DNA. Herein, liquid chromatography-tandem mass spectrometry was for the first time developed and validated for the simultaneous determination of doxorubicin and its major metabolites doxorubicinol, doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The liquid–liquid extraction of a 10 μL mouse plasma sample with chloroform:methanol (4:1, v/v) and use of the selected reaction monitoring mode led to less matrix effect and better sensitivity. The lower limits of quantification levels were 0.5 ng/mL for doxorubicin, 0.1 ng/mL for doxorubicinol, and 0.01 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone. The standard curves were linear over the range of 0.5–200 ng/mL for doxorubicin; 0.1–200 ng/mL for doxorubicinol; and 0.01–50 ng/mL for doxorubicinone, doxorubicinolone, and 7-deoxydoxorubicinone in mouse plasma. The intra and inter-day relative standard deviation and relative errors for doxorubicin and its four metabolites at four quality control concentrations were 0.9–13.6% and –13.0% to 14.9%, respectively. This method was successfully applied to the pharmacokinetic study of doxorubicin and its metabolites after intravenous administration of doxorubicin at a dose of 1.3 mg/kg to female BALB/c nude mice. [ABSTRACT FROM AUTHOR]

• Gene complexation affinity of polycation controls tightness and size of polyplex. • Smaller, tighter polyplex delivered more pDNA into nucleus than larger, looser one. • Larger polyplex had slower cytosolic and nuclear transport of pDNA than smaller one. • Too tighter polyplex made poor gene expression due to poor pDNA release in nucleus. • Tightness and size of polyplex strongly influence polymeric gene transfection. The delivery of plasmid DNA (pDNA) using polycations has been investigated for several decades; however, obstacles that limit efficient gene delivery still hinder the clinical application of gene therapy. One of the major limiting factors is controlling pDNA binding affinity with polymers to control the complexation and decomplexation of polyplexes. To address this challenge, polycations of α-poly(L -lysine) (APL) and ε-poly(L -lysine) (EPL) were used to prepare variable complexation/decomplexation polyplexes with binding affinities ranging from too tight to too loose and sizes ranging from small to large. APL-EPL/ATP-pDNA polyplexes were also prepared to compare the effects of endosomolytic ATP on complexation/decomplexation and the sizes of polyplexes. The results showed that smaller and tighter polyplexes delivered more pDNA into the cells and into the nucleus than the larger and looser polyplexes. Larger polyplexes exhibited slower cytosolic transport and consequently less nuclear delivery of pDNA than smaller polyplexes. Tighter polyplexes exhibited poor pDNA release in the nucleus, leading to no improvement in transfection efficiency. Thus, polyplexes should maintain a balance between complexation and decomplexation and should have optimal sizes for effective cellular uptake, cytosolic transport, nuclear import, and gene expression. Understanding the effects of complexation/decomplexation and size is important when designing effective polymer-based electrostatic gene carriers. [ABSTRACT FROM AUTHOR]