Combined BET and MEK Inhibition synergistically suppresses melanoma by targeting YAP1.

Rationale: The response rate to the MEK inhibitor trametinib in BRAF-mutated melanoma patients is less than 30%, and drug resistance develops rapidly, but the mechanism is still unclear. Yes1-associated transcriptional regulator (YAP1) is highly expressed in melanoma and may be related to MEK inhibitor resistance. The purpose of this study was to investigate the mechanism of YAP1 in MEK inhibitor resistance in melanoma and to screen YAP1 inhibitors to further determine whether YAP1 inhibition reverses MEK inhibitor resistance. Methods: On the one hand, we analyzed paired melanoma and adjacent tissue samples using RNA-seq and found that the Hippo-YAP1 signaling pathway was the top upregulated pathway. On the other hand, we evaluated the transcriptomes of melanoma samples from patients before and after trametinib treatment and investigated the correlation between YAP1 expression and trametinib resistance. Then, we screened for inhibitors that repress YAP1 expression and investigated the mechanisms. Finally, we investigated the antitumor effect of YAP1 inhibition combined with MEK inhibition both in vitro and in vivo. Results: We found that YAP1 expression levels upon trametinib treatment in melanoma patients were correlated with resistance to trametinib. YAP1 was translocated into the nucleus after trametinib treatment in melanoma cells, which could render resistance to MEK inhibition. Thus, we screened for inhibitors that repress YAP1 expression and identified multiple bromodomain and extra-terminal (BET) inhibitors, including NHWD-870, as hits. BET inhibition repressed YAP1 expression by decreasing BRD4 binding to the YAP1 promoter. Consistently, YAP1 overexpression was sufficient to reverse the proliferation defect caused by BRD4 depletion. In addition, the BET inhibitor NHWD-870 acted synergistically with trametinib to suppress melanoma growth in vitro and in vivo. Conclusions: We identified a new vulnerability for MEK inhibitor-resistant melanomas, which activated Hippo pathway due to elevated YAP1 activity. Inhibition of BRD4 using BET inhibitors suppressed YAP1 expression and led to blunted melanoma growth when combined with treatment with the MEK inhibitor trametinib.

Molecular insights into sarcopenia: ferroptosis-related genes as diagnostic and therapeutic targets.

Ferroptosis, characterized by iron accumulation and lipid peroxidation, leads to cell death. Growing evidence suggests the involvement of ferroptosis in sarcopenia. However, the fundamental ferroptosis-related genes (FRGs) for sarcopenia diagnosis, prognosis, and therapy remain elusive. This study aimed to identify molecular biomarkers of ferroptosis in sarcopenia patients. Gene expression profiles were obtained from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) between normal and sarcopenia samples were identified using the 'limma' package in R software. FRGs were extracted from GeneCards and FerrDB databases. Functional enrichment analysis determined the roles of DEGs using the 'clusterProfiler' package. A protein-protein network was constructed using Cytoscape software. Immune infiltration analysis and receiver operating characteristic (ROC) analysis were performed. mRNA-miRNA, mRNA-TF, and mRNA-drug interactions were predicted using ENCORI, hTFtarget, and CHIPBase databases. The network was visualized using Cytoscape. We identified 46 FRGs in sarcopenia. Functional enrichment analysis revealed their involvement in critical biological processes, including responses to steroid hormones and glucocorticoids. KEGG enrichment analysis implicated pathways such as carbon metabolism, ferroptosis, and glyoxylate in sarcopenia. Totally, 11 hub genes were identified, and ROC analysis demonstrated their potential as sensitive and specific markers for sarcopenia in both datasets. Additionally, differences in immune cell infiltration were observed between normal and sarcopenia samples. The hub genes identified in this study are closely associated with ferroptosis in sarcopenia and can effectively differentiate sarcopenia from controls. CDKN1A, CS, DLD, FOXO1, HSPB1, LDHA, MDH2, and YWHAZ show high sensitivity and specificity for sarcopenia diagnosis.Communicated by Ramaswamy H. Sarma.

Integrated single-cell and bulk RNA sequencing analysis identified pyroptosis-related signature for diagnosis and prognosis in osteoarthritis.

Osteoarthritis (OA), a degenerative disease of the joints, has one of the highest disability rates worldwide. This study investigates the role of pyroptosis-related genes in osteoarthritis and their expression in different chondrocyte subtypes at the individual cell level. Using OA-related datasets for single-cell RNA sequencing and RNA-seq, the study identified PRDEGs and DEGs and conducted Cox regression analysis to identify independent prognostic factors for OA. CASP6, NOD1, and PYCARD were found to be prognostic factors. Combined Weighted Gene Correlation Network Analysis with PPI network, a total of 15 hub genes related to pyroptosis were involved in the notch and oxidative phosphorylation pathways, which could serve as biomarkers for the diagnosis and prognosis of OA patients. The study also explored the heterogeneity of chondrocytes between OA and normal samples, identifying 19 single-cell subpopulation marker genes that were significantly different among 7 chondrocyte cell clusters. AGT, CTSD, CYBC, and THYS1 were expressed differentially among different cell subpopulations, which were associated with cartilage development and metabolism. These findings provide valuable insights into the molecular mechanisms underlying OA and could facilitate the development of new therapeutic strategies for this debilitating disease.

Preparation of clarithromycin floating core-shell systems (CSS) using multi-nozzle semi-solid extrusion-based 3D printing.

Matrix erosion is unavoidable during the release of poorly soluble drugs from gastric floating delivery system (GFDDS), which shortens the floating time and diminishes drug release. We fabricated a core-shell system (CSS) consisting of a low-density drug-loaded shell and a floating core using multi-nozzle semi-solid extrusion (SSE) 3D printing technology. The clarithromycin (CAM) loading capacity of the shell was 81.7%. The floating core paste provided structural support during printing and formed a hollow structure in CAM CSS, which increased the buoyancy in the early stage of drug release. In addition, the floating core had numerous micro-airbags that swelled when the solution penetrated the core, and generated CO2. The micro-airbag structure and CO2 generation further increased the buoyancy of CSS. The CAM CSS achieved 74.5% (w/w) drug loading, 8 h sustained release, and immediate and prolonged floating (>10 h). This structure of CSS and floating core provide a novel perspective for constructing a stable gastric floating drug delivery system.

Effect of a 2-HP-ß-Cyclodextrin Formulation on the Biological Transport and Delivery of Chemotherapeutic PLGA Nanoparticles.

BACKGROUND: The aim of this work was to develop a novel and feasible modification strategy by utilizing the supramolecular effect of 2-hydroxypropyl-beta-cyclodextrin (2-HP-ß-CD) for enhancing the biological transport efficiency of paclitaxel (PTX)-loaded poly(lactide-co-glycolide) (PLGA) nanoparticles. METHODS: PTX-loaded 2-HP-ß-CD-modified PLGA nanoparticles (2-HP-ß-CD/PLGA NPs) were prepared using the modified emulsion method. Nano-characteristics, drug release behavior, in vitro cytotoxicity, cellular uptake profiles and in vivo bio-behavior of the nanoparticles were then characterized. RESULTS: Compared with the plain PLGA NPs, 2-HP-ß-CD/PLGA NPs exhibited smaller particle sizes (151.03±1.36 nm), increased entrapment efficiency (~49.12% increase) and sustained drug release. When added to A549 human lung cancer cells, compared with PLGA NPs, 2-HP-ß-CD/PLGA NPs exhibited higher cytotoxicity in MTT assays and improved cellular uptake efficiency. Pharmacokinetic analysis showed that the AUC value of 2-HP-ß-CD/PLGA NPs was 2.4-fold higher than commercial Taxol® and 1.7-fold higher than plain PLGA NPs. In biodistribution assays, 2-HP-ß-CD/PLGA NPs exhibited excellent stability in the circulation. CONCLUSION: The results of this study suggest that the formulation that contains 2-HP-ß-CD can prolong PTX release, enhance drug transport efficiency and serve as a potential tumor targeting system for PTX.

Preparation of High-Drug-Loaded Clarithromycin Gastric-Floating Sustained-Release Tablets Using 3D Printing.

The high-drug-loaded sustained-release gastric-floating clarithromycin (CAM) tablets were proposed and manufactured via semisolid extrusion (SSE)-based 3D printing. The physical and mechanical properties, such as dimensions, weight variation, friability, and hardness, were accessed according to the quality standards of Chinese Pharmacopoeia (Ch.P). The interactions among the drug-excipients were evaluated via differential scanning calorimetry (DSC), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) techniques. Next, the rheological properties of the paste and the effect of the excipients and solvents were evaluated. Finally, a very high drug-loading of up to 81.7% (w/w) with the sustain release time of 8 h (125 mg) and 12 h (250 mg) was achieved. The results revealed the potential of SSE for achieving a high drug loading and identified the suitable properties of the paste for SSE-based 3D printing.

Micro-interaction of mucin tear film interface with particles: The inconsistency of pharmacodynamics and precorneal retention of ion-exchange, functionalized, Mt-embedded nano- and microparticles.

Physiological reflexes and anatomical barriers render traditional eye drop delivery inefficient. We previously reported that drug-loaded nanoparticles and microspheres prepared from montmorillonite and Eudragit polymers exhibited good sustained-release and lowered intraocular pressure. Here, we compared the performance of optimized formulations to select the most suitable formulation for glaucoma therapy. We found that the microspheres had much higher encapsulation efficiency and drug loading than nanoparticles. Moreover, cytocompatibility experiments demonstrated that nanoparticles showed more severe cytotoxicity than microspheres, probably due to their smaller particles, enhanced cell uptake, and intracellular solubility. Interestingly, the pre-corneal retention time of nanoparticles reflected a clear advantage over microspheres, while the duration of the pharmacological effect of nanoparticles was not as good as that of microspheres: compared with the nanoparticle depressurization duration of only 8 h, the microspheres continuously depressurized for 12 h. The slower release of the microspheres and its micro-interaction mechanism with the discontinuous mucin layer of the tear film led to the inconsistency between duration of pharmacodynamics and fluorescence ocular retention time. In summary, the lower cytotoxicity and longer pharmacological effect of microspheres indicate their potential advantages for glaucoma applications.

Cross-linked thermosensitive nanohydrogels for ocular drug delivery with a prolonged residence time and enhanced bioavailability.

AIM: A temperature-triggered, cross-linked nano hydrogel formulation (NPs-gel) was prepared to prolong the residence time of dexamethasone (DXM) in the eye and increase its bioavailability. RESEARCH DESIGN AND METHODS: The NPs-gel was prepared by combining a high pressure homogenization method with a cold solution method. Soy lecithin E200, lecithin oil, glycerol, kolliphor P188, kolliphor P407, and polycarbophil were the excipients used for the formation of NPs-gel containing DXM. The nanoparticle size, temperature-sensitive phase transition characteristics, in vitro and in vivo release behavior, corneal permeability, and eye irritation level of the NPs-gel were evaluated. RESULTS: The NPs-gel had slightly larger particle size than the DXM-loaded nanoparticles, yet it retained the properties of nanoparticles such as surface effect and size effect. The phase transition temperature was 33.2 °C, which is within the trigger conditions of intraocular temperature. Under physiological conditions, the adhesion and adhesion work of the NPs-gel were 1.1 and 2.1 times that of an in situ-formed gel, and the gel strength of NPs-gel was 1.8 times that of an in situ-formed gel. These results indicate that NPs-gel has greater adhesion and mechanical strength. The area under the curve of NPs-gel was 3.08 and 1.51 times that of DXM-loaded nanoparticles and in situ-formed gel, showing higher bioavailability. CONCLUSION: The NPs-gel is a suitable formulation to further enhance ocular drug delivery.

PLGA Nanoparticle Platform for Trans-Ocular Barrier to Enhance Drug Delivery: A Comparative Study Based on the Application of Oligosaccharides in the Outer Membrane of Carriers.

PURPOSE: The trans-ocular barrier is a key factor limiting the therapeutic efficacy of triamcinolone acetonide. We developed a poly(lactic-co-glycolic acid) nanoparticles (PLGA NPs) surface modified respectively with 2-hydroxypropyl-ß-cyclodextrin (2-HP-ß-CD), chitosan oligosaccharide and trehalose. Determination of the drug/nanoparticles interactions, characterization of the nanoparticles, in vivo ocular compatibility tests, comparisons of their corneal permeability and their pharmacokinetics in aqueous humor were carried out. METHODS: All PLGA NPs were prepared by the single emulsion and evaporation method and the drug-nanoparticle interaction was studied. The physiochemical features and in vitro corneal permeability of NPs were characterized while the aqueous humor pharmacokinetics was performed to evaluate in vivo corneal permeability of NPs. Ocular compatibility of NPs was investigated through Draize and histopathological test. RESULTS: The PLGA NPs with lactide/glycolide ratio of 50:50 and small particle size (molecular weight 10 kDa) achieved optimal drug release and corneal permeability. Surface modification with different oligosaccharides resulted in uniform particle sizes and similar drug-nanoparticle interactions, although 2-HP-ß-CD/PLGA NPs showed the highest entrapment efficiency. In vitro evaluation and aqueous humor pharmacokinetics further revealed that 2-HP-ß-CD/PLGA NPs had greater trans-ocular permeation and retention compared to chitosan oligosaccharide/PLGA and trehalose/PLGA NPs. No ocular irritation in vivo was detected after applying modified/unmodified PLGA NPs to rabbit's eyes. CONCLUSION: 2-HP-ß-CD/PLGA NPs are a promising nanoplatform for localized ocular drug delivery through topical administration.

Incorporation of ion exchange functionalized-montmorillonite into solid lipid nanoparticles with low irritation enhances drug bioavailability for glaucoma treatment.

Montmorillonite-loaded solid lipid nanoparticles with good biocompatibility, using Betaxolol hydrochloride as model drug, were prepared by the melt-emulsion sonication and low temperature-solidification methods and drug bioavailability was significantly improved in this paper for the first time to application to the eye. The appropriate physical characteristics were showed, such as the mean particle size, Zeta potential, osmotic pressure, pH values, entrapping efficiency (EE%) and drug content (DC%), all showed well suited for possible ocular application. In vitro release experiment indicated that this novel system could continuously release 57.83% drugs within 12 h owing to the dual drug controlled-release effect that was achieved by ion-exchange feature of montmorillonite and structure of solid lipid nanoparticles. Low irritability and good compatibility of nanoparticles were proved by both CAM-TBS test and cytotoxicity experiment. We first discovered from the results of Rose Bengal experiment that the hydrophilicity of the drug-loaded nanoparticles surface was increased during the loading and releasing of the hydrophilic drug, which could contribute to prolong the ocular surface retention time of drug in the biological interface membrane of tear-film/cornea. The results of in vivo pharmacokinetic and pharmacodynamics studies further confirmed that increased hydrophilicity of nanoparticles surface help to improve the bioavailability of the drug and reduce intraocular pressure during administration. The results suggested this novel drug delivery system could be potentially used as an in situ drug controlled-release system for ophthalmic delivery to enhance the bioavailability and efficacy.

Preparation and application of subdivided tablets using 3D printing for precise hospital dispensing.

This study aimed to use three-dimensional printing technology to provide patients with accurate, safe and convenient subdivided drugs and bring the transformation of subdivided drugs' fabrication in the hospital. The formulation, preparation process, model and printing parameters, relationship between dose and preset model for printing of spironolactone of 2 mg, 4 mg and hydrochlorothiazide of 5 mg subdivided tablets prepared by three-dimensional printers were investigated in the study. The three-dimensional printed material consists of commercial tablets powders and other excipients, including lactose, corn starch, microcrystalline cellulose, and so on. Mass variation, drug content and drug content uniformity of subdivided tablets obtained by three-dimensional printing were compared with the pharmacists splitting subdivided tablets. Besides, the results from fourier transform infrared spectroscopy, differential scanning calorimetry and X-ray powder diffraction confirmed that the preparation process of spironolactone of 2 mg, 4 mg and hydrochlorothiazide of 5 mg did not change the crystal structure of the active pharmaceutical ingredient. Furthermore, mass variation, drug content range and drug content uniformity of spironolactone of 2 mg, 4 mg and hydrochlorothiazide of 5 mg tablets split by pharmacists failed to comply with European Pharmacopoeia and Chinese Pharmacopoeia, while those of the three-dimensional printed subdivided tablets did. After the review of the ethics committee as a new technology for hospital dispensing, three-dimensional printed spironolactone subdivided tablets of 2 mg have been used in clinical inpatients and was accepted by pharmacists, nurses and patients. Compared with tablets subdivided split by pharmacists, three-dimensional printed spironolactone tablets of 2 mg were more accurate, safer and more customized, which indicated considerable potential in using three-dimensional printing technology as a new method for hospital dispensing.

Semi-solid extrusion 3D printing ODFs: an individual drug delivery system for small scale pharmacy.

Orodispersible films (ODFs) are promising drug delivery systems for customized medicines as it provide an alternative approach to increase consumer acceptance by advantages of rapid dissolution and administration without water. The aim of this study was to develop a platform to support the realization of tailored treatments suitable for the extemporaneous production of ODFs by semi-solid extrusion (SSE) 3D printing (3DP). Hydroxypropyl methyl cellulose (HPMC) was used as the polymer of ODFs, and levocetirizine hydrochloride was used as the model drug. The optimal formulation was HPMC:API:PS:maltitol:sucralose at a ratio of 64:10:10:15:1. Seventeen percent HPMC solution and optimal formulation were used to prepare film precursors. The impact of dynamic viscosities and fluid mechanics difference on printing applicability was discussed. The ODFs of cube designs with aimed dose of 1.25 mg, 2.5 mg, and 5 mg were printed by SSE 3DP. Good linear relationship between theoretical model volume and drug content (R2 = 0.999) and good dose accuracy indicate that 3DP is a suitable method for preparing individualized ODFs.

Enhancing Betulinic Acid Dissolution Rate and Improving Antitumor Activity via Nanosuspension Constructed by Anti-Solvent Technique.

PURPOSE: The aim of this study was to prepare and evaluate betulinic acid nanosuspension (BA-NS) for new drug delivery to enhance its solubility and in vitro anti-tumor activity. METHODS: BA-NS was formulated by an anti-solvent precipitation method using the Box-Behnken design (BBD). Particle size (PS) and Zeta potential were measured by laser particle size analysis. The drug solid state after freeze drying was characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD) and Fourier transform infrared spectroscopy (FTIR) after freeze drying. The saturation solubility and dissolution rate were determined by solubility assay and in vitro dissolution studies, respectively. The in vitro cytotoxicity assay was performed using 3-(4,5-dimethylthiazole)-2,5-diphenltetraazolium bromide (MTT) method. RESULTS: The PS was 129.7±12.2 nm having a Zeta potential of -28.1±4.5 mV and the polydispersity index (PDI) was 0.231±0.013, which confirmed that the nanosuspension was in the stable amorphous state. A series of characterization experiments demonstrated that nanoparticles retained original effective structure and existed as spherical or near-spherical nanoparticles in the nanosuspension, but the drug transferred from the crystal state to the amorphous state. The form of lyophilized BA-NS was very successful in enhancing the dissolution rate in PH-dependent way. The cytotoxicity assay revealed that BA-NS could significantly enhance the in vitro anti-proliferation against tumor cells compared to the BA suspension (BA-S). CONCLUSION: The BA-NS can remarkably improve solubility and in vitro antitumor activity, which seems very promising for the treatment of cancers in practical application.

Characterisation of 2-HP-ß-cyclodextrin-PLGA nanoparticle complexes for potential use as ocular drug delivery vehicles.

Aim: 2-HP-ß-cyclodextrin-PLGA nanoparticle complexes were prepared to enhance the aqueous humour delivery of Triamcinolone acetonide.Materials & methods: Drug-loaded 2-HP-ß-CD/PLGA nanoparticle complexes prepared by adapting a quasi-emulsion solvent evaporation technique. In vitro drug release, in vitro transcorneal permeation study, histopathological study and in vivo transcorneal penetration of PLGA nanoparticles and 2-HP-ß-CD/PLGA nanoparticle complexes were evaluated. Results: Particle size distributions of 2-HP-ß-CD/PLGA nanoparticle complexes were 149.4 ± 3.7 nm and presented stable system. Corneal penetration studies revealed steady sustained drug release (First-order); 2-HP-ß-CD/PLGA nanoparticle complexes increased ocular bioavailability by increasing dispersion in the tear film and improving drug release. Conclusion: 2-HP-ß-CD/PLGA nanoparticle complex formulation is a promising alternative to conventional eye drops.

Design, Synthesis, and Anticancer Effect Studies of Iridium(III) Polypyridyl Complexes against SGC-7901 Cells.

Three iridium(III) complexes ([Ir(Hppy)2(L)](PF6) (Hppy = 2-phenylpyridine, L = 5-nitrophenanthroline, NP), 1; 5-nitro-6-amino-phenanthroline (NAP), 2; and 5,6-diamino-phenanthroline (DAP) 3 were synthesized and characterized. The cytotoxicities of Ir(III) complexes 1-3 against cancer cell lines SGC-7901, A549, HeLa, Eca-109, HepG2, BEL-7402, and normal NIH 3T3 cells were investigated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide (MTT) method. The results showed that the three iridium(III) complexes had moderate in vitro anti-tumor activity toward SGC-7901 cells with IC50 values of 3.6 ± 0.1 µM for 1, 14.1 ± 0.5 µM for 2, and 11.1 ± 1.3 µM for 3. Further studies showed that 1-3 induce cell apoptosis/death through DNA damage, cell cycle arrest at the S or G0/G1 phase, ROS elevation, increased levels of Ca2+, high mitochondrial membrane depolarization, and cellular ATP depletion. Transwell and Colony-Forming assays revealed that complexes 1-3 can also effectively inhibit the metastasis and proliferation of tumor cells. These results demonstrate that 1-3 induce apoptosis in SGC-7901 cells through ROS-mediated mitochondrial damage and DNA damage pathways, as well as by inhibiting cell invasion, thereby exerting anti-tumor cell proliferation activity in vitro.

Lymphatic clearance is the main drainage route of lamotrigine-loaded micelles following delivery to the brain.

OBJECTIVES: This study aimed to investigate the clearance pathways of lamotrigine (LTG)-loaded micelles by intranasal administration and intracerebral injection in the brain and whether nanoparticles can induce the inflammation promoted by interleukin-6 (IL-6), accelerating the phagocytosis of drug particles in the brain and drainage through lymphatics. METHODS: The drug concentrations in the deep cervical lymph node, superficial cervical lymph node, brain tissues and jugular vein, the pharmacokinetic parameters, and the concentrations of IL-6 in deep cervical lymph node and brain tissues were investigated following UPLC/MS, DAS3.0, ELISA statistically analysed. KEY FINDINGS: The AUC0- t of deep cervical lymph node after intranasal and intracerebral injection was 1.93, 2.77, 1.34 times and 3.06, 16.4, 3.34 times higher compared with the superficial cervical lymph node, jugular vein and brain tissue, respectively. After intranasal administration of lamotrigine-loaded micelles for 30 min, the IL-6 concentrations in deep cervical lymph node and brain tissue were significantly increased (P < 0.05). CONCLUSIONS: These results suggested that lamotrigine micelles were primarily cleared from the brain by lymphatics rather than blood clearance. Also, the nanoparticle induced the increase in IL-6 level after entering the brain suggested that nanoparticles might induce the inflammation promoted by IL-6 in the brain, accelerating the clearance of drug particles in the brain and drainage through lymphatics.

Applications of excipients in the field of 3D printed pharmaceuticals.

The aim of this study was to determine the effect of varying excipient content on the formation and physical properties of 3 D printed tablets. Fifteen different excipient preparations were formed into tablets with radii of 5 mm and thickness of 2 mm, using binder jetting (BJ). The tablets were analyzed by assessing visual and microstructural appearance, friability, hardness, and disintegration time. We found that filling agents with high water solubility (e.g. D-sucrose), binding agents with a high viscosity in solution (e.g. polyethylene glycol 4000) and moistening agent with higher water content can increase the bonding strength and hardness of the 3 D printed tablets and prolonged their disintegration time. This work has demonstrated that the type of excipient and its concentration affects the properties of the 3 D printed tablet. This article may be used as a guide for elucidation of the effects of using conventional tablet excipients in the field of 3 D printed pharmaceuticals. The present work should enable the identification of excipients that satisfy requirements, reduce analysis time, and improve efficiency.

Ruthenium complex delivery using liposomes to improve bioactivity against HeLa cells via the mitochondrial pathway.

AIM: The aim of this study was to encapsulate a ruthenium complex [Ru(ttbpy)2PIP](ClO4)2 (Ru) in liposomes to enhance their antitumor effect on human cervical cancer. METHODS: The Ru-loaded PEGylated liposomes (Ru-Lip) were prepared using thin-film hydration method. The mechanism of action was studied. RESULTS: A novel Ru was successfully synthesized. Ru-Lip showed stronger cytotoxic activity against HeLa cells than Ru. Ru-Lip demonstrated a more significant increase in apoptosis, reactive oxygen species production and apoptosis-associated processes (intracellular calcium concentration, cytochrome c release and activation of Bax and caspase-3) than Ru. Ru-Lip exhibited greater blockade efficacy in the cell cycle G1 phase and greater DNA damage than Ru. CONCLUSION: Ru-Lip significantly elevates the anticancer effect via reactive oxygen species-mediated mitochondrial dysfunctional pathway.

A potential nanoparticle-loaded in situ gel for enhanced and sustained ophthalmic delivery of dexamethasone.

Increasing the permeability of drugs across the cornea is key to improving drug absorption by the eye. This study presents a newly developed in situ gel loaded with nanoparticles, which could achieve controlled drug release and high ocular drug bioavailability by avoiding rapid precorneal clearance. The physicochemical parameters of the formulation were investigated and showed uniform size, physical stability, and favorable rheological and gelling properties. Ex vivo permeation studies revealed significantly higher drug release from the in situ gel loaded with nanoparticles compared to the conventional poloxamer in situ gel and the drug solution. When compared with a marketed formulation, the in situ gel loaded with nanoparticles provided slower controlled release and higher ocular bioavailability of dexamethasone. In conclusion, the developed nanoparticle-loaded in situ gel can successfully increase drug ocular bioavailability by enhancing contact time with the ocular surface and permeation through the cornea.

Montmorillonite/chitosan nanoparticles as a novel controlled-release topical ophthalmic delivery system for the treatment of glaucoma.

BACKGROUND: To date, the rapid clearance from ocular surface has been a huge obstacle for using eye drops to treat glaucoma, since it has led to the short preocular residence time and low bioavailability. METHODS: The novel nanoparticles (NPs) were designed for topical ophthalmic controlled drug delivery system through intercalating the BH into the interlayer gallery of Na-montmorillonite (Na+Mt) and then further enchasing chitosan nanoparticles. The resulting nanoparticles had a positive charge (+29±0.18 mV) with an average diameter of 460±0.6 nm. RESULTS: In vitro study of drug release profiles suggested controlled release pattern. The irritation experiment analysis on both human immortalized cornea epithelial cell (iHCEC) and chorioallantoic membrane-trypan blue staining (CAM-TBS) showed good tolerance for ocular tissues. It was interestingly found that the nanoparticles could enter into iHCEC from the result of cellular uptake experiment measured by confocal layer scan microscopy (CLSM). Meanwhile, multilayered iHCEC was used to simulate the barrier of corneal epithelial cells for in vivo preocular retention capacity study, which suggested that BH-Mt/CS NPs could prolong the retention time in comparison with BH solution. The ocular pharmacokinetics studied by microdialysis sampling technique showed that AUC0-t and MRT0-t of BH-Mt/CS NPs were 1.99-fold and 1.75-fold higher than those of BH solution, indicating higher bioavailability. Moreover, the study of blood drug concentration, few researchers have reported, showed that low level drug could enter into blood, suggesting lower systematic side effect. Importantly, pharmacodynamics studies suggested that BH-Mt/CS NPs could make a significant decreased intraocular pressure on glaucomatous rabbits. CONCLUSION: Inspired by these advance of montmorillonite/chitosan nanoparticles, we envision that the BH-Mt/CS NPs will be a potential carrier for BH, opening up the possible applications in glaucoma therapy.