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1.
Sci Transl Med ; 14(662): eabn3758, 2022 09 14.
Article in English | MEDLINE | ID: mdl-36103515

ABSTRACT

The management of antibiotic-resistant, bacterial biofilm infections in chronic skin wounds is an increasing clinical challenge. Despite advances in diagnosis, many patients do not derive benefit from current anti-infective/antibiotic therapies. Here, we report a novel class of naturally occurring and semisynthetic epoxy-tiglianes, derived from the Queensland blushwood tree (Fontainea picrosperma), and demonstrate their antimicrobial activity (modifying bacterial growth and inducing biofilm disruption), with structure/activity relationships established against important human pathogens. In vitro, the lead candidate EBC-1013 stimulated protein kinase C (PKC)-dependent neutrophil reactive oxygen species (ROS) induction and NETosis and increased expression of wound healing-associated cytokines, chemokines, and antimicrobial peptides in keratinocytes and fibroblasts. In vivo, topical EBC-1013 induced rapid resolution of infection with increased matrix remodeling in acute thermal injuries in calves. In chronically infected diabetic mouse wounds, treatment induced cytokine/chemokine production, inflammatory cell recruitment, and complete healing (in six of seven wounds) with ordered keratinocyte differentiation. These results highlight a nonantibiotic approach involving contrasting, orthogonal mechanisms of action combining targeted biofilm disruption and innate immune induction in the treatment of chronic wounds.


Subject(s)
Phorbols , Animals , Anti-Bacterial Agents/pharmacology , Biofilms , Cattle , Humans , Keratinocytes , Mice , Wound Healing
2.
Front Oncol ; 11: 701933, 2021.
Article in English | MEDLINE | ID: mdl-34490102

ABSTRACT

Glioblastoma (GB) remains an aggressive malignancy with an extremely poor prognosis. Discovering new candidate drug targets for GB remains an unmet medical need. Caveolin-1 (Cav-1) has been shown to act variously as both a tumour suppressor and tumour promoter in many cancers. The implications of Cav-1 expression in GB remains poorly understood. Using clinical and genomic databases we examined the relationship between tumour Cav-1 gene expression (including its spatial distribution) and clinical pathological parameters of the GB tumour and survival probability in a TCGA cohort (n=155) and CGGA cohort (n=220) of GB patients. High expression of Cav-1 represented a significant independent predictor of shortened survival (HR = 2.985, 5.1 vs 14.9 months) with a greater statistically significant impact in female patients and in the Proneural and Mesenchymal GB subtypes. High Cav-1 expression correlated with other factors associated with poor prognosis: IDH w/t status, high histological tumour grade and low KPS score. A total of 4879 differentially expressed genes (DEGs) in the GB tumour were found to correlate with Cav-1 expression (either positively or negatively). Pathway enrichment analysis highlighted an over-representation of these DEGs to certain biological pathways. Focusing on those that lie within a framework of epithelial to mesenchymal transition and tumour cell migration and invasion we identified 27 of these DEGs. We then examined the prognostic value of Cav-1 when used in combination with any of these 27 genes and identified a subset of combinations (with Cav-1) indicative of co-operative synergistic mechanisms of action. Overall, the work has confirmed Cav-1 can serve as an independent prognostic marker in GB, but also augment prognosis when used in combination with a panel of biomarkers or clinicopathologic parameters. Moreover, Cav-1 appears to be linked to many signalling entities within the GB tumour and as such this work begins to substantiate Cav-1 or its associated signalling partners as candidate target for GB new drug discovery.

3.
Biomater Sci ; 9(18): 6037-6051, 2021 Sep 14.
Article in English | MEDLINE | ID: mdl-34357362

ABSTRACT

Glioblastoma (GBM) is the most aggressive malignant brain tumor and is associated with a very poor prognosis. The standard treatment for newly diagnosed patients involves total tumor surgical resection (if possible), plus irradiation and adjuvant chemotherapy. Despite treatment, the prognosis is still poor, and the tumor often recurs within two centimeters of the original tumor. A promising approach to improving the efficacy of GBM therapeutics is to utilize biomaterials to deliver them locally at the tumor site. Local delivery to GBM offers several advantages over systemic administration, such as bypassing the blood-brain barrier and increasing the bioavailability of the therapeutic at the tumor site without causing systemic toxicity. Local delivery may also combat tumor recurrence by maintaining sufficient drug concentrations at and surrounding the original tumor area. Herein, we critically appraised the literature on local delivery systems based within the following categories: polymer-based implantable devices, polymeric injectable systems, and hydrogel drug delivery systems. We also discussed the negative effect of hypoxia on treatment strategies and how one might utilize local implantation of oxygen-generating biomaterials as an adjuvant to enhance current therapeutic strategies.


Subject(s)
Brain Neoplasms , Glioblastoma , Biocompatible Materials/therapeutic use , Blood-Brain Barrier , Brain Neoplasms/drug therapy , Drug Delivery Systems , Glioblastoma/drug therapy , Humans
4.
NPJ Biofilms Microbiomes ; 7(1): 13, 2021 02 05.
Article in English | MEDLINE | ID: mdl-33547326

ABSTRACT

Novel therapeutics designed to target the polymeric matrix of biofilms requires innovative techniques to accurately assess their efficacy. Here, multiple particle tracking (MPT) was developed to characterize the physical and mechanical properties of antimicrobial resistant (AMR) bacterial biofilms and to quantify the effects of antibiotic treatment. Studies employed nanoparticles (NPs) of varying charge and size (40-500 nm) in Pseudomonas aeruginosa PAO1 and methicillin-resistant Staphylococcus aureus (MRSA) biofilms and also in polymyxin B (PMB) treated Escherichia coli biofilms of PMB-sensitive (PMBSens) IR57 and PMB-resistant (PMBR) PN47 strains. NP size-dependent and strain-related differences in the diffusion coefficient values of biofilms were evident between PAO1 and MRSA. Dose-dependent treatment effects induced by PMB in PMBSens E. coli biofilms included increases in diffusion and creep compliance (P < 0.05), not evident in PMB treatment of PMBR E. coli biofilms. Our results highlight the ability of MPT to quantify the diffusion and mechanical effects of antibiotic therapies within the AMR biofilm matrix, offering a valuable tool for the pre-clinical screening of anti-biofilm therapies.


Subject(s)
Biofilms/growth & development , Escherichia coli/physiology , Methicillin-Resistant Staphylococcus aureus/physiology , Polymyxin B/pharmacology , Pseudomonas aeruginosa/physiology , Single Molecule Imaging/methods , Biofilms/drug effects , Dose-Response Relationship, Drug , Drug Resistance, Bacterial , Escherichia coli/drug effects , Methicillin-Resistant Staphylococcus aureus/drug effects , Microbial Sensitivity Tests , Microbial Viability/drug effects , Microscopy, Confocal , Nanoparticles , Particle Size , Pseudomonas aeruginosa/drug effects
5.
J Control Release ; 331: 364-375, 2021 03 10.
Article in English | MEDLINE | ID: mdl-33497747

ABSTRACT

The current decline in antimalarial drug efficacy due to the evolution of resistant Plasmodium strains calls for new strategies capable of improving the bioavailability of antimalarials, especially of those whose lipophilic character imparts them a low solubility in biological fluids. Here we have designed, synthesized and characterized amphiphilic zwitterionic block copolymers forming nanoparticles capable of penetrating the intestinal epithelium that can be used for oral administration. Poly(butyl methacrylate-co-morpholinoethyl sulfobetaine methacrylate) (PBMA-MESBMA)-based nanoparticles exhibited a specific targeting to Plasmodium falciparum-infected vs. parasite-free red blood cells (74.8%/0.8% respectively), which was maintained upon encapsulation of the lipophilic antimalarial drug curcumin (82.6%/0.3%). The in vitro efficacy of curcumin upon encapsulation was maintained relative to the free compound, with an IC50 around 5 µM. In vivo assays indicated a significantly increased curcumin concentration in the blood of mice one hour after being orally fed PBMA-MESBMA-curcumin in comparison to the administration of free drug (18.7 vs. 2.1 ng/ml, respectively). At longer times, however, plasma curcumin concentration equaled between free and encapsulated drug, which was reflected in similar in vivo antimalarial activities in Plasmodium yoelii yoelii-infected mice. Microscopic analysis in blood samples of fluorescently labeled PBMA-MESBMA revealed the presence of the polymer inside P. yoelii yoelii-parasitized erythrocytes one hour after oral administration to infected animals.


Subject(s)
Antimalarials , Malaria , Nanoparticles , Plasmodium yoelii , Administration, Oral , Animals , Malaria/drug therapy , Mice , Plasmodium falciparum
6.
Cancers (Basel) ; 12(12)2020 Dec 11.
Article in English | MEDLINE | ID: mdl-33322379

ABSTRACT

The secondary structures of Scherer commonly known as perineuronal and perivascular satellitosis have been identified as a histopathological hallmark of diffuse, invasive, high-grade gliomas. They are recognised as perineuronal satellitosis when clusters of neoplastic glial cells surround neurons cell bodies and perivascular satellitosis when such tumour cells surround blood vessels infiltrating Virchow-Robin spaces. In this review, we provide an overview of emerging knowledge regarding how interactions between neurons and glioma cells can modulate tumour evolution and how neurons play a key role in glioma growth and progression, as well as the role of perivascular satellitosis into mechanisms of glioma cells spread. At the same time, we review the current knowledge about the role of perineuronal satellitosis and perivascular satellitosis within the tumour microenvironment (TME), in order to highlight critical knowledge gaps in research space.

7.
Biomater Sci ; 8(18): 4997-5004, 2020 Sep 15.
Article in English | MEDLINE | ID: mdl-32931543

ABSTRACT

Interleukin-13 (IL-13) drives cells of myeloid origin towards a more anti-inflammatory phenotype, but delivery to the brain remains problematic. Herein, we show that heparin-based cryogel microcarriers load high amounts of IL-13, releasing it slowly. Intra-striatal injection of loaded microcarriers caused local up-regulation of ARG1 in myeloid cells for pro-regenerative immunomodulation in the brain.


Subject(s)
Heparin , Interleukin-13 , Brain , Cryogels
8.
Int J Pharm ; 579: 119187, 2020 Apr 15.
Article in English | MEDLINE | ID: mdl-32135228

ABSTRACT

The epithelial permeation of water-soluble fluorescent PAMAM dendrons based on 7H-benz[de] benzimidazo [2,1-a] isoquinoline-7-one as a fluorescent core across epithelial cell models MDCK I and MDCK II has been quantified. Hydrodynamic radii have been derived from self-diffusion coefficients obtained via pulsed-gradient spin-echo Nuclear Magnetic Resonance (PGSE-NMR). Results indicate that these dendritic molecules are molecularly disperse, non-aggregating, and only slightly larger than their parent homologues. MDCK I permeability studies across epithelial barriers show that these dendritic molecules are biocompatible with the chosen epithelial in-vitro model and can permeate across MDCK cell monolayers. Permeability is demonstrated to be a property of dendritic size and cell barrier restrictiveness indicating that paracellular mechanisms play the predominant role in the transport of these molecules.


Subject(s)
Dendrimers/chemical synthesis , Epithelial Cells/metabolism , Fluorescent Dyes/chemistry , Fluorescent Dyes/chemical synthesis , Permeability , Animals , Cells, Cultured , Dogs , Magnetic Resonance Spectroscopy
9.
FASEB J ; 34(1): 1710-1727, 2020 01.
Article in English | MEDLINE | ID: mdl-31914660

ABSTRACT

Despite the importance of the tumor microenvironment in regulating tumor progression, few in vitro models have been developed to understand the effects of non-neoplastic cells and extracellular matrix (ECM) on drug resistance in glioblastoma (GBM) cells. Using CellTrace-labeled human GBM and microglial (MG) cells, we established a 2D co-culture including various ratios of the two cell types. Viability, proliferation, migration, and drug response assays were carried out to assess the role of MG. A 3D model was then established using a hyaluronic acid-gelatin hydrogel to culture a mixture of GBM and MG and evaluate drug resistance. A contact co-culture of fluorescently labeled GBM and MG demonstrated that MG cells modestly promoted tumor cell proliferation (17%-30% increase) and greater migration of GBM cells (>1.5-fold increase). Notably, the presence of MG elicited drug resistance even when in a low ratio (10%-20%) relative to co-cultured tumor cells. The protective effect of MG on GBM was greater in the 3D model (>100% survival of GBM when challenged with cytotoxics). This new 3D human model demonstrated the influence of non-neoplastic cells and matrix on chemoresistance of GBM cells to three agents with different mechanisms of action suggesting that such sophisticated in vitro approaches may facilitate improved preclinical testing.


Subject(s)
Brain Neoplasms/drug therapy , Cell Movement/drug effects , Cell Proliferation/drug effects , Cytotoxins/pharmacology , Drug Resistance, Neoplasm/drug effects , Glioblastoma/drug therapy , Microglia/drug effects , Aged , Antineoplastic Agents/pharmacology , Brain Neoplasms/pathology , Cell Line, Tumor , Coculture Techniques/methods , Extracellular Matrix/drug effects , Extracellular Matrix/pathology , Glioblastoma/pathology , Humans , Hyaluronic Acid/pharmacology , Hydrogels/pharmacology , Male , Microglia/pathology , Middle Aged , Tumor Microenvironment/drug effects
10.
Front Med (Lausanne) ; 7: 594295, 2020.
Article in English | MEDLINE | ID: mdl-33425942

ABSTRACT

The coronavirus disease (COVID-19) outbreak has presented enormous challenges for healthcare, societal, and economic systems worldwide. There is an urgent global need for a universal vaccine to cover all SARS-CoV-2 mutant strains to stop the current COVID-19 pandemic and the threat of an inevitable second wave of coronavirus. Carbon dioxide is safe and superior antimicrobial, which suggests it should be effective against coronaviruses and mutants thereof. Depending on the therapeutic regime, CO2 could also ameliorate other COVID-19 symptoms as it has also been reported to have antioxidant, anti-inflammation, anti-cytokine effects, and to stimulate the human immune system. Moreover, CO2 has beneficial effects on respiratory physiology, cardiovascular health, and human nervous systems. This article reviews the rationale of early treatment by inhaling safe doses of warmed humidified CO2 gas, either alone or as a carrier gas to deliver other inhaled drugs may help save lives by suppressing SARS-CoV-2 infections and excessive inflammatory responses. We suggest testing this somewhat counter-intuitive, but low tech and safe intervention for its suitability as a preventive measure and treatment against COVID-19. Overall, development and evaluation of this therapy now may provide a safe and economical tool for use not only during the current pandemic but also for any future outbreaks of respiratory diseases and related conditions.

11.
Nanoscale Adv ; 2(10): 4498-4509, 2020 Oct 13.
Article in English | MEDLINE | ID: mdl-36132909

ABSTRACT

Glioblastoma multiforme (GBM) is the most aggressive type of malignant brain tumour, which is associated with a poor two-year survival rate and a high rate of fatal recurrence near the original tumour. Focal/local drug delivery devices hold promise for improving therapeutic outcomes for GBM by increasing drug concentrations locally at the tumour site, or by facilitating the use of potent anti-cancer drugs that are poorly permeable across the blood brain barrier (BBB). For inoperable tumours, stereotactic delivery to the tumour necessitates the development of nanoscale/microscale injectable drug delivery devices. Herein we assess the ability of a novel class of polymer nanotube (based on poly(ethylene glycol) (PEG)) to load doxorubicin (a mainstay breast cancer therapeutic with poor BBB permeability) and release it slowly. The drug loading properties of the PEG nanotubes could be tuned by varying the degree of carboxylic acid functionalisation and hence the capacity of the nanotubes to electrostatically bind and load doxorubicin. 70% of the drug was released over the first seven days followed by sustained drug release for the remaining two weeks tested. Unloaded PEG nanotubes showed no toxicity to any of the cell types analysed, whereas doxorubicin loaded nanotubes decreased GBM cell viability (C6, U-87 and U-251) in a dose dependent manner in 2D in vitro culture. Finally, doxorubicin loaded PEG nanotubes significantly reduced the viability of in vitro 3D GBM models whilst unloaded nanotubes showed no cytotoxicity. Taken together, these findings show that polymer nanotubes could be used to deliver alternative anti-cancer drugs for local therapeutic strategies against brain cancers.

12.
Int J Pharm X ; 1: 100006, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31517271

ABSTRACT

The aim of this work was to evaluate the mucus-permeating properties of nanocarriers using zein nanoparticles (NPZ) coated with a Gantrez® AN-thiamine conjugate (GT). NPZ were coated by incubation at different GT-to-zein ratios: 2.5% coating with GT (GT-NPZ1), 5% (GT-NPZ2) and 10% (GT-NPZ3). During the process, the GT conjugate formed a polymer layer around the surface of zein nanoparticles. For GT-NPZ2, the thickness of this corona was estimated between 15 and 20 nm. These nanocarriers displayed a more negative zeta potential than uncoated NPZ. The diffusivity of nanoparticles was evaluated in pig intestinal mucus by multiple particle tracking analysis. GT-NPZ2 displayed a 28-fold higher diffusion coefficient within the mucus layer than NPZ particles. These results align with in vivo biodistribution studies in which NPZ displayed a localisation restricted to the mucus layer, whereas GT-NPZ2 were capable of reaching the intestinal epithelium. The gastro-intestinal transit of mucoadhesive (NPZ) and mucus-permeating nanoparticles (GT-NPZ2) was also found to be different. Thus, mucoadhesive nanoparticles displayed a significant accumulation in the stomach of animals, whereas mucus-penetrating nanoparticles appeared to exit the stomach more rapidly to access the small intestine of animals.

13.
Adv Drug Deliv Rev ; 142: 62-74, 2019 03 01.
Article in English | MEDLINE | ID: mdl-30974131

ABSTRACT

Mucus is a dynamic barrier which covers and protects the underlying mucosal epithelial membrane against bacteria and foreign particles. This protection mechanism extends to include therapeutic macromolecules and nanoparticles (NPs) through trapping of these particles. Mucus is not only a physical barrier that limiting particles movements based on their sizes but it selectively binds with particles through both hydrophilic and lipophilic interactions. Therefore, nano-carriers for mucosal delivery should be designed to eliminate entrapment by the mucus barrier. For this reason, different strategies have been approached for both solid nano-carriers and liquid core nano-carriers to synthesise muco-diffusive nano-carrier. Among these nano-strategies, Self-Emulsifying Drug Delivery System (SEDDS) was recognised as very promising nano-carrier for mucus delivery. The system was introduced to enhance the dissolution and bioavailability of orally administered insoluble drugs. SEDDS has shown high stability against intestinal enzymatic activity and more importantly, relatively rapid permeation characteristics across mucus barrier. The high diffusivity of SEDDS has been tested using various in vitro measurement techniques including both bulk and individual measurement of droplets diffusion within mucus. The selection and processing of an optimum in vitro technique is of great importance to avoid misinterpretation of the diffusivity of SEDDS through mucus barrier. In conclusion, SEDDS is a system with high capacity to diffuse through intestinal mucus even though this system has not been studied to the same extent as solid nano-carriers.


Subject(s)
Drug Delivery Systems , Mucus/metabolism , Animals , Diffusion , Emulsions , Humans , Mucus/chemistry , Nanotechnology , Permeability
14.
J Pharm Sci ; 108(7): 2421-2429, 2019 07.
Article in English | MEDLINE | ID: mdl-30849462

ABSTRACT

Peanut allergy is one of the most prevalent and severe of food allergies with no available cure. The aim of this work was to evaluate the potential of an oral immunotherapy based on the use of a roasted peanut extract encapsulated in nanoparticles with immunoadjuvant properties. For this, a polymer conjugate formed by the covalent binding of mannosamine to the copolymer of methyl vinyl ether and maleic anhydride was first synthetized and characterized. Then, the conjugate was used to prepare nanoparticles with an important capability to diffuse through the mucus layer and reach, in a large extent, the intestinal epithelium, including Peyer's patches. Their immunotherapeutic potential was evaluated in a model of presensitized CD1 mice to peanut. After completing therapy, mice underwent an intraperitoneal challenge with peanut extract. Nanoparticle-treatment was associated with both less serious anaphylaxis symptoms and higher survival rates than control, confirming the protective effect of this formulation against the challenge.


Subject(s)
Arachis/immunology , Nanoparticles/chemistry , Peanut Hypersensitivity/immunology , Peanut Hypersensitivity/therapy , Adjuvants, Immunologic/pharmacology , Administration, Oral , Animals , Disease Models, Animal , Female , Immunologic Factors/immunology , Immunotherapy/methods , Male , Mice , Polymers/chemistry , Rats , Rats, Wistar
15.
Vaccines (Basel) ; 8(1)2019 Dec 31.
Article in English | MEDLINE | ID: mdl-31906120

ABSTRACT

Enterotoxigenic Escherichia coli (ETEC) strains are a major cause of illness and death in neonatal and recently weaned pigs. The immune protection of the piglets derives from maternal colostrum, since this species does not receive maternal antibodies through the placenta. In the present study, outer membrane vesicles (OMVs) obtained from main ETEC strains involved in piglet infection (F4 and F18 serotypes), encapsulated into zein nanoparticles coated with Gantrez®® AN-mannosamine conjugate, were used to orally immunize mice and pregnant sows. Loaded nanoparticles were homogeneous and spherical in a shape, with a size of 220-280 nm. The diffusion of nanoparticles through porcine intestinal mucus barrier was assessed by a Multiple Particle Tracking technique, showing that these particles were able to diffuse efficiently (1.3% diffusion coefficient), validating their oral use. BALB/c mice were either orally immunized with free OMVs or encapsulated into nanoparticles (100 µg OMVs/mouse). Results indicated that a single dose of loaded nanoparticles was able to elicit higher levels of serum specific IgG1, IgG2a and IgA, as well as intestinal IgA, with respect to the free antigens. In addition, nanoparticles induced an increase in levels of IL-2, IL-4 and IFN-γ with respect to the administration of free OMVs. Orally immunized pregnant sows with the same formulation elicited colostrum-, serum- (IgG, IgA or IgM) and fecal- (IgA) specific antibodies and, what is most relevant, offspring suckling piglets presented specific IgG in serum. Further studies are needed to determine the infection protective capacity of this new oral subunit vaccine.

16.
High Alt Med Biol ; 19(2): 141-148, 2018 06.
Article in English | MEDLINE | ID: mdl-29620950

ABSTRACT

Bailey, Damian Miles, Benjamin S. Stacey, and Mark Gumbleton. A systematic review and meta-analysis reveals altered drug pharmacokinetics in humans during acute exposure to terrestrial high altitude-clinical justification for dose adjustment? High Alt Med Biol. 19:141-148, 2018. OBJECTIVE: While physiological responses during acute ascent to terrestrial high altitude (HA) have the potential to alter the pharmacokinetics (PKs) that define absorption and disposition of medicinal drugs, there have been no systematic reviews and meta-analyses performed to date. METHODS: We conducted a systematic literature search in June 2017 using NCBI PubMed, EMBASE, Web of Science, and Ovid MEDLINE databases to identify relevant observational studies. Studies were deemed eligible based on the following criteria: (1) participants: healthy, nonacclimatized male or female lowlanders (born and bred at sea level) and (2) environment: exposure to low altitude (LA, ≤600 m), followed by terrestrial high altitude (HA, ≤24 hours to ≥2500 m), the time course specifically selected to avoid interpretive complications associated with erythrocytosis. All PK parameters were standardized to be in the same units and the weighted standardized mean difference (SMD) calculated using a combination of fixed and random effects models with heterogeneity evaluated using χ2 and I2 statistics. RESULTS: Of 20,840 studies reviewed, 6 prospective cohort studies (n = 75) qualified for inclusion, with participants exposed to a mean altitude of 4025 (mean) ± 380 (SD) m. We observed increases for absorption half-life (SMD: 0.40, 95% CI: 0.01-0.80, p = 0.04], elimination half-life (SMD: 0.89, 95% CI: 0.30-1.48, p = 0.003), and erythrocyte binding (SMD: 0.52, 95% CI: 0.16-0.88, p = 0.004) and reduction in clearance (SMD: -0.56, 95% CI: -1.13 to 0.00, p = 0.05). CONCLUSIONS: Collectively, these findings reveal impairments in both oral absorption and corresponding clearance of the, although limited, sample of drugs at HA that may potentially require closer patient monitoring and dose adjustments to maintain therapeutic efficacy and avoid incidental toxicity.


Subject(s)
Absorption, Physiological/physiology , Acclimatization/physiology , Altitude , Pharmacokinetics , Adult , Erythrocytes/physiology , Female , Half-Life , Humans , Male , Metabolic Clearance Rate , Middle Aged , Prospective Studies
17.
J Control Release ; 277: 165-172, 2018 05 10.
Article in English | MEDLINE | ID: mdl-29574041

ABSTRACT

BACKGROUND: The aim of the study was to develop an oral self-emulsifying drug delivery system (SEDDS) for exenatide and to evaluate its in vivo efficacy. METHODS: Exenatide was lipidised via hydrophobic ion pairing with sodium docusate (DOC) and incorporated in SEDDS consisting of 35% Cremophor EL, 25% Labrafil 1944, 30% Capmul-PG 8 and 10% propylene glycol. Exenatide/DOC was characterized in terms of lipophilicity evaluating the octanol/water phase distribution (logP). Exenatide/DOC SEDDS were characterized via droplet size analysis, drug release characteristics (log DSEDDS/release medium determination) and mucus permeation studies. Furthermore, the impact of orally administered exenatide/DOC SEDDS on blood glucose level was investigated in vivo on healthy male Sprague-Dawley rats. RESULTS: Hydrophobic ion pairing in a molar ratio of 1:4 (exenatide:DOC) increased the effective logP of exenatide from -1.1 to 2.1. SEDDS with a payload of 1% exenatide/DOC had a mean droplet size of 45.87 ±â€¯2.9 nm and a Log DSEDDS/release medium of 1.9 ±â€¯0.05. Permeation experiments revealed 2.7-fold improved mucus diffusion for exenatide/DOC SEDDS compared to exenatide in solution. Orally administered exenatide/DOC SEDDS showed a relative bioavailability (versus s.c.) of 14.62% ±â€¯3.07% and caused a significant (p < .05) 20.6% decrease in AUC values of blood glucose levels. CONCLUSION: According to these results, hydrophobic ion pairing in combination with SEDDS represents a promising tool for oral peptide delivery.


Subject(s)
Drug Delivery Systems/methods , Emulsifying Agents/metabolism , Exenatide/metabolism , Administration, Oral , Animals , Caco-2 Cells , Cell Survival/drug effects , Cell Survival/physiology , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical/methods , Emulsifying Agents/administration & dosage , Exenatide/administration & dosage , Humans , Hypoglycemic Agents/administration & dosage , Hypoglycemic Agents/metabolism , Male , Rats , Rats, Sprague-Dawley
18.
J Control Release ; 273: 21-29, 2018 03 10.
Article in English | MEDLINE | ID: mdl-29355620

ABSTRACT

The objective of this study was to investigate the impact of different hydrophobic ion pairs (HIP) on the oral bioavailability of the model drug octreotide in pigs. Octreotide was ion paired with the anionic surfactants deoxycholate, decanoate and docusate differing in lipophilicity. These hydrophobic ion pairs were incorporated in self-emulsifying drug delivery systems (SEDDS) based on BrijO10, octyldodecanol, propylene glycol and ethanol in a concentration of 5mg/ml. SEDDS were characterized regarding size distribution, zeta potential, stability towards lipase, log DSEDDS/release medium and mucus diffusion behavior. The oral bioavailability of octreotide was evaluated in pigs via LC-MS/MS analyses. Most efficient ion pairing was achieved at a molar ratio of 1:3 (peptide: surfactant). SEDDS containing the octreotide-deoxycholate, -decanoate and -docusate ion pair exhibited a mean droplet size of 152nm, 112nm and 191nm and a zeta potential of -3.7, -4.6 and -5.7mV, respectively. They were completely stable towards degradation by lipase and showed a log DSEDDS/release medium of 1.7, 1.8 and 2.7, respectively. The diffusion coefficient of these SEDDS was in the range of 0.03, 0.11 and 0.17×10-9cm2/s, respectively. In vivo studies with these HIPs showed no improvement in the oral bioavailability in case of octreotide-decanoate. In contrast, octreotide-deoxycholate and octreotide-docusate SEDDS resulted in a 17.9-fold and 4.2-fold higher bioavailability vs. CONTROL: According to these results, hydrophobic ion pairing could be identified as a key parameter for SEDDS to achieve high oral bioavailability.


Subject(s)
Antineoplastic Agents, Hormonal/administration & dosage , Drug Delivery Systems , Octreotide , Animals , Antineoplastic Agents, Hormonal/chemistry , Antineoplastic Agents, Hormonal/pharmacokinetics , Biological Availability , Decanoates/chemistry , Decanoates/pharmacokinetics , Deoxycholic Acid/administration & dosage , Deoxycholic Acid/chemistry , Deoxycholic Acid/pharmacokinetics , Dioctyl Sulfosuccinic Acid/administration & dosage , Dioctyl Sulfosuccinic Acid/chemistry , Dioctyl Sulfosuccinic Acid/pharmacokinetics , Drug Liberation , Hydrophobic and Hydrophilic Interactions , Lipase/chemistry , Male , Octreotide/administration & dosage , Octreotide/chemistry , Octreotide/pharmacokinetics , Swine
19.
Int J Biol Macromol ; 110: 328-335, 2018 Apr 15.
Article in English | MEDLINE | ID: mdl-28965967

ABSTRACT

The aim of this work was to evaluate the potential application of an original oral immunotherapy, based on the use of nanoparticles, against an experimentally induced peanut allergy. In this context, a roasted peanut extract, containing the main allergenic proteins, were encapsulated into poly(anhydride) nanoparticles. The resulting peanut-loaded nanoparticles (PE-NP) displayed a mean size of about 150nm and a significantly lower surface hydrophobicity than empty nanoparticles (NP). This low hydrophobicity correlated well with a higher in vitro diffusion in pig intestinal mucus than NP and an important in vivo capability to reach the intestinal epithelium and Peyer's patches. The immunotherapeutic capability of PE-NP was evaluated in a model of pre-sensitized CDI mice to peanut. After completing therapy of three doses of peanut extract, either free or encapsulated into nanoparticles, mice underwent an intraperitoneal challenge. Anaphylaxis was evaluated by means of assessment of symptom scores and mouse mast cell protease-1 levels (mMCPT-1). PE-NP treatment was associated with significant lower levels of mMCPT-1, and a significant survival rate after challenge, confirming the protective effect of this formulation against the challenge. In summary, this nanoparticle-based formulation might be a valuable strategy for peanut-specific immunotherapy.


Subject(s)
Allergens , Arachis/chemistry , Desensitization, Immunologic/methods , Nanoparticles , Peanut Hypersensitivity/drug therapy , Plant Proteins , Administration, Oral , Allergens/chemistry , Allergens/pharmacokinetics , Allergens/pharmacology , Animals , Disease Models, Animal , Female , Mice , Nanoparticles/chemistry , Nanoparticles/therapeutic use , Peanut Hypersensitivity/immunology , Peanut Hypersensitivity/pathology , Plant Proteins/chemistry , Plant Proteins/pharmacokinetics , Plant Proteins/pharmacology
20.
Biotechnol J ; 12(10)2017 Oct.
Article in English | MEDLINE | ID: mdl-28786556

ABSTRACT

Time-series image capture of in vitro 3D spheroidal cancer models embedded within an extracellular matrix affords examination of spheroid growth and cancer cell invasion. However, a customizable, comprehensive and open source solution for the quantitative analysis of such spheroid images is lacking. Here, the authors describe INSIDIA (INvasion SpheroID ImageJ Analysis), an open-source macro implemented as a customizable software algorithm running on the FIJI platform, that enables high-throughput high-content quantitative analysis of spheroid images (both bright-field gray and fluorescent images) with the output of a range of parameters defining the spheroid "tumor" core and its invasive characteristics.


Subject(s)
High-Throughput Screening Assays/methods , Image Processing, Computer-Assisted/methods , Spheroids, Cellular/pathology , Aged , Algorithms , Caveolin 1/analysis , Caveolin 1/genetics , Cell Line, Tumor , Cell Proliferation , Extracellular Matrix , Gene Knockdown Techniques , Humans , Male , Software , Spheroids, Cellular/metabolism
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