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1.
J Control Release ; 367: 687-696, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38262487

ABSTRACT

High aspect-ratio nanomaterials have recently emerged as promising drug delivery vehicles due to evidence of strong cellular association and prolonged in vivo circulation times. Cyclic peptide - polymer conjugate nanotubes are excellent candidates due to their elongated morphology, their supramolecular composition and high degree of pliability due to the versatility in manipulating amino acid sequence and polymer type. In this work, we explore the use of a nanotube structure on which a potent anti-cancer drug, camptothecin, is attached alongside hydrophilic or amphiphilic RAFT polymers, which shield the cargo. We show that subtle modifications to the cleavable linker type and polymer architecture have a dramatic influence over the rate of drug release in biological conditions. In vitro studies revealed that multiple cancer cell lines in 2D and 3D models responded effectively to the nanotube treatment, and analogous fluorescently labelled materials revealed key mechanistic information regarding the degree of cellular uptake and intracellular fate. Importantly, the ability to instruct specific drug release profiles indicates a potential for these nanomaterials as vectors which can provide sustained drug concentrations for a maximal therapeutic effect.


Subject(s)
Antineoplastic Agents , Nanotubes, Peptide , Nanotubes , Neoplasms , Humans , Polymers/chemistry , Peptides, Cyclic/chemistry , Drug Delivery Systems , Nanotubes/chemistry , Drug Liberation
2.
Adv Drug Deliv Rev ; 200: 114962, 2023 09.
Article in English | MEDLINE | ID: mdl-37321376

ABSTRACT

Nanotechnology research over the past several decades has been aimed primarily at improving the physicochemical properties of small molecules to produce druggable candidates as well as for tumor targeting of cytotoxic molecules. The recent focus on genomic medicine and the success of lipid nanoparticles for mRNA vaccines have provided additional impetus for the development of nanoparticle drug carriers for nucleic acid delivery, including siRNA, mRNA, DNA, and oligonucleotides, to create therapeutics that can modulate protein deregulation. Bioassays and characterizations, including trafficking assays, stability, and endosomal escape, are key to understanding the properties of these novel nanomedicine formats. We review historical nanomedicine platforms, characterization methodologies, challenges to their clinical translation, and key quality attributes for commercial translation with a view to their developability into a genomic medicine. New nanoparticle systems for immune targeting, as well as in vivo gene editing and in situ CAR therapy, are also highlighted as emerging areas.


Subject(s)
Nanomedicine , Nanoparticles , Humans , Nanomedicine/methods , Drug Delivery Systems/methods , Delayed-Action Preparations , Nanotechnology/methods , Nanoparticles/chemistry , RNA, Messenger
3.
J Control Release ; 356: 580-594, 2023 04.
Article in English | MEDLINE | ID: mdl-36918085

ABSTRACT

Here, we aimed to chemically modify PAMAM dendrimers using lysine as a site-selective anchor for successfully delivering mRNA while maintaining a low toxicity profile. PAMAM dendrimers were multi-functionalised by amidation reactions in a regioselective, quantitative and stepwise manner with carefully selected property-modifying surface groups. Alternatively, novel lysine-based dendrimers were prepared in the same manner with the aim to unlock their potential in gene delivery. The modified dendrimers were then formulated with Cy5-EGFP mRNA by bulk mixing via liquid handling robotics across different nitrogen to phosphate ratios. The resulting dendriplexes were characterised by size, charge, mRNA encapsulation, and mRNA binding affinity. Finally, their in-vitro delivery activity was systematically investigated across key cellular trafficking stages to relate chemical design to cellular effect. We demonstrate our findings in different cell lines and benchmarked relative to a commercially available transfection agent, jetPEI®. We demonstrate that specific surface modifications are required to generate small, reliable and well-encapsulated positively charged dendriplex complexes. Furthermore, we show that introduction of fusogenic groups is essential for driving endosomal escape and achieving cellular delivery and translation of mRNA in these cell lines.


Subject(s)
Dendrimers , Dendrimers/chemistry , Polylysine , Transfection , Gene Transfer Techniques
5.
Anal Chem ; 93(8): 3742-3749, 2021 03 02.
Article in English | MEDLINE | ID: mdl-33606520

ABSTRACT

Imaging mass cytometry (IMC) offers the opportunity to image metal- and heavy halogen-containing xenobiotics in a highly multiplexed experiment with other immunochemistry-based reagents to distinguish uptake into different tissue structures or cell types. However, in practice, many xenobiotics are not amenable to this analysis, as any compound which is not bound to the tissue matrix will delocalize during aqueous sample-processing steps required for IMC analysis. Here, we present a strategy to perform IMC experiments on a water-soluble polysarcosine-modified dendrimer drug-delivery system (S-Dends). This strategy involves two consecutive imaging acquisitions on the same tissue section using the same instrumental platform, an initial laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MSI) experiment followed by tissue staining and a standard IMC experiment. We demonstrated that settings can be found for the initial ablation step that leave sufficient residual tissue for subsequent antibody staining and visualization. This workflow results in lateral resolution for the S-Dends of 2 µm followed by imaging of metal-tagged antibodies at 1 µm.


Subject(s)
Image Cytometry , Water , Drug Delivery Systems , Mass Spectrometry , Staining and Labeling
6.
Front Surg ; 7: 43, 2020.
Article in English | MEDLINE | ID: mdl-32766274

ABSTRACT

Background: Thyroid cancer is the most common endocrine malignancy worldwide. Primary treatment with surgery and radioactive iodine is usually successful, however, there remains a small proportion of thyroid cancers that are resistant to these treatments, and often represent aggressive forms of the disease. Since the 1950s, in vitro thyroid culture systems have been used in thyroid cancer research. In vitro culture models have evolved from 2-dimensional thyrocyte monolayers into physiologically functional 3-dimensional organoids. Recently, research groups have utilized in vitro thyroid cancer models to identify numerous genetic and epigenetic factors that are involved with tumorigenesis as well as test the efficacy of cytotoxic drugs on thyroid cancer cells and identify cancer stem cells within thyroid tumors. Objective of Review: The objective of this literature review is to summarize how thyroid in vitro culture models have evolved and highlight how in vitro models have been fundamental to thyroid cancer research. Type of Review: Systematic literature review. Search Strategy: The National Institute for Health and Care Excellence (NICE) Healthcare and Databases Advanced Search (HDAS) tool was used to search EMBASE, Medline and PubMed databases. The following terms were included in the search: "in vitro" AND "thyroid cancer". The search period was confined from January 2008 until June 2019. A manual search of the references of review articles and other key articles was also performed using Google Scholar. Evaluation Method: All experimental studies and review articles that explicitly mentioned the use of in vitro models for thyroid cancer research in the title and/or abstract were considered. Full-text versions of all selected articles were evaluated. Experimental studies were reviewed and grouped according to topic: genetics/epigenetics, drug testing/cancer treatment, and side populations (SP)/tumor microenvironment (TME). Results: Three thousand three hundred and seventy three articles were identified through database and manual searches. One thousand two hundred and sixteen articles remained after duplicates were removed. Five hundred and eighty nine articles were excluded based on title and/or abstract. Of the remaining 627 full-text articles: 24 were review articles, 332 related to genetic/epigenetics, 240 related to drug testing/treatments, and 31 related to SP/TME. Conclusion: In vitro cell culture models have been fundamental in thyroid cancer research. There have been many advances in culture techniques- developing complex cellular architecture that more closely resemble tumors in vivo. Genetic and epigenetic factors that have been identified using in vitro culture models can be used as targets for novel drug therapies. In the future, in vitro systems will facilitate personalized medicine, offering bespoke treatments to patients.

7.
Biomacromolecules ; 21(8): 3332-3341, 2020 08 10.
Article in English | MEDLINE | ID: mdl-32672451

ABSTRACT

This paper describes the synthesis of star polymers designed for future drug-delivery applications. A generation-5 lysine dendrimer was used as a macroinitiator for the ring-opening polymerization of the sarcosine N-carboxyanhydride monomer to produce 32-arm star polymers with narrow molar mass distributions and desirable hydrodynamic size control. Fluorescent dye-labeled polymers were dosed in mice to measure plasma pharmacokinetics. Long circulation times were observed, representing ideal properties for biophysical targeting of tumors. In vivo efficacy of one of these star polymers conjugated to the therapeutic molecule SN-38 was evaluated in mice bearing SW620 xenografted tumors to demonstrate high antitumor activity and low body weight loss compared to the SN-38 prodrug irinotecan and this shows the potential of these delivery systems. As a further build, we demonstrated that these star polymers can be easily chain-end-functionalized with useful chemical moieties, giving opportunities for future receptor-targeting strategies. Finally, we describe the synthetic advantages of these star polymers that make them attractive from a pharmaceutical manufacturing perspective and report characterization of the polymers with a variety of techniques.


Subject(s)
Dendrimers , Pharmaceutical Preparations , Animals , Mice , Peptides , Polymers , Sarcosine/analogs & derivatives
8.
J Pediatr Endocrinol Metab ; 21(6): 555-568, 2020 Oct 22.
Article in English | MEDLINE | ID: mdl-33600687

ABSTRACT

AIM: To compare the efficacy and safety of Exubera® (EXU) with subcutaneous (SC) insulin in children, ages 6-11 years, with type 1 diabetes mellitus. DESIGN AND METHODS: 121 children were randomized to receive EXU or SC insulin, plus intermediate/ long-acting insulin for 12 weeks. Change in HbA1c was the primary efficacy endpoint. RESULTS: Decreases from baseline HbA1c were comparable between treatment groups ( difference between adjusted mean decrease from baseline [EXU - SC insulin], -0.23 [95% CI, -0.49, 0.03]). Differences between groups on pulmonary function tests were small and not significant. Mild to moderate cough occurred in 24.6% of EXU versus 6.8% of SC insulin patients. The risk for hypoglycemia was comparable between EXU and SC insulin (relative risk 0.88 [95% CI, 0.71, 1.11]). Increased insulin antibodies with EXU were not associated with clinical findings. CONCLUSION: The efficacy and safety profiles shown in this study are the foundation for further investigation of EXU in this population.


Subject(s)
Biomarkers/blood , Diabetes Mellitus, Type 1/drug therapy , Hypoglycemic Agents/administration & dosage , Insulin Antibodies/blood , Insulin/administration & dosage , Administration, Inhalation , Blood Glucose/analysis , Child , Diabetes Mellitus, Type 1/immunology , Diabetes Mellitus, Type 1/pathology , Female , Follow-Up Studies , Humans , Injections, Subcutaneous , Insulin Antibodies/immunology , Male , Prognosis
9.
Mol Ther ; 27(11): 1950-1962, 2019 11 06.
Article in English | MEDLINE | ID: mdl-31427168

ABSTRACT

Lipid nanoparticles have great potential for delivering nucleic-acid-based therapeutics, but low efficiency limits their broad clinical translation. Differences in transfection capacity between in vitro models used for nanoparticle pre-clinical testing are poorly understood. To address this, using a clinically relevant lipid nanoparticle (LNP) delivering mRNA, we highlight specific endosomal characteristics in in vitro tumor models that impact protein expression. A 30-cell line LNP-mRNA transfection screen identified three cell lines having low, medium, and high transfection that correlated with protein expression when they were analyzed in tumor models. Endocytic profiling of these cell lines identified major differences in endolysosomal morphology, localization, endocytic uptake, trafficking, recycling, and endolysosomal pH, identified using a novel pH probe. High-transfecting cells showed rapid LNP uptake and trafficking through an organized endocytic pathway to lysosomes or rapid exocytosis. Low-transfecting cells demonstrated slower endosomal LNP trafficking to lysosomes and defective endocytic organization and acidification. Our data establish that efficient LNP-mRNA transfection relies on an early and narrow endosomal escape window prior to lysosomal sequestration and/or exocytosis. Endocytic profiling should form an important pre-clinical evaluation step for nucleic acid delivery systems to inform model selection and guide delivery-system design for improved clinical translation.


Subject(s)
Gene Expression , Lipids/chemistry , Nanoparticles , RNA, Messenger/genetics , Transfection , Cell Line, Tumor , Endocytosis , Endosomes/metabolism , Flow Cytometry , Fluorescent Antibody Technique , Genes, Reporter , Humans , Hydrogen-Ion Concentration , Lysosomes/metabolism , Nanoparticles/chemistry , RNA, Messenger/administration & dosage , Transfection/methods
10.
Biomater Sci ; 7(8): 3418-3424, 2019 Aug 01.
Article in English | MEDLINE | ID: mdl-31268069

ABSTRACT

We report on the synthesis of four poly(2-methyl-2-oxazoline) modified lysine dendrimers with different residual groups or modifications on the dendrimer core, including: amino groups (positive charge), carboxyl groups (negative charge), and two drug molecules, one of which has a high log P. We looked at the in vivo distribution amongst three main liver cell types: hepatocytes, liver sinusoidal endothelial cells (LSECs) and Kupffer cells (KCs) and found differences in cell distribution and uptake concentrations dependent on these residual groups. In particular, the amino-functional polymer showed greater uptake by the hepatocytes whilst the carboxyl-functionalised polymer exhibited greater uptake by KCs and LSECs. These findings provide insight into which professional scavenger cells of the liver remove these types of nanoparticles from the bloodstream and we describe some of the design criteria to consider when creating novel drug delivery systems.


Subject(s)
Dendrimers/chemistry , Liver/metabolism , Lysine/chemistry , Lysine/metabolism , Polyamines/chemistry , Administration, Intravenous , Animals , Biological Transport , Female , Hydrophobic and Hydrophilic Interactions , Lysine/administration & dosage , Lysine/pharmacokinetics , Mice , Rhodamines/chemistry , Tissue Distribution
11.
CNS Spectr ; 24(5): 496-506, 2019 10.
Article in English | MEDLINE | ID: mdl-30419989

ABSTRACT

OBJECTIVE: Two similarly designed extension studies evaluated the long-term safety and tolerability of desvenlafaxine for the treatment of children and adolescents with major depressive disorder (MDD). Efficacy was evaluated as a secondary objective. METHODS: Both 6-month, open-label, flexible-dose extension studies enrolled children and adolescents who had completed one of two double-blind, placebo-controlled, lead-in studies. One lead-in study included a 1-week transition period prior to the extension study. Patients received 26-week treatment with flexible-dose desvenlafaxine (20-50 mg/d). Safety assessments included comprehensive psychiatric evaluations, vital sign assessments, laboratory evaluations, 12-lead electrocardiogram, physical examination with Tanner assessment, and Columbia-Suicide Severity Rating Scale. Adverse events (AEs) were collected throughout the studies. Efficacy was assessed using the Children's Depression Rating Scale-Revised (CDRS-R). RESULTS: A total of 552 patients enrolled (completion rates: 66.4 and 69.1%). AEs were reported by 79.4 and 79.1% of patients in the two studies; 8.9 and 5.2% discontinued due to AEs. Treatment-emergent suicidal ideation or behavior was reported for 16.6 and 14.1% of patients in the two studies. Mean (SD) CDRS-R total score decreased from 33.83 (11.93) and 30.92 (10.20) at the extension study baseline to 24.31 (7.48) and 24.92 (8.45), respectively, at week 26. CONCLUSION: Desvenlafaxine 20 to 50 mg/d was generally safe and well tolerated with no new safety signals identified in children and adolescents with MDD who received up to 6 months of treatment in these studies. Patients maintained the reduction in severity of depressive symptoms observed in all treatment groups at the end of the lead-in study.


Subject(s)
Antidepressive Agents/adverse effects , Depressive Disorder, Major/drug therapy , Desvenlafaxine Succinate/adverse effects , Long Term Adverse Effects/epidemiology , Adolescent , Antidepressive Agents/administration & dosage , Antidepressive Agents/therapeutic use , Child , Desvenlafaxine Succinate/administration & dosage , Desvenlafaxine Succinate/therapeutic use , Drug Tolerance , Female , Humans , Male , Treatment Outcome
12.
Macromol Rapid Commun ; 39(19): e1800265, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30062740

ABSTRACT

The high incidence of prostate carcinogenesis has prompted the search for novel effective treatment approaches. We have employed curcumin (Curc) and diethylstilbestrol (DES) to synthesize a series of polyacetal (PA)-based combination conjugates for prostate cancer (PCa) treatment. Given their bihydroxyl functionalities, Curc and DES molecules were incorporated into a PA mainchain using a one-pot reaction between diols and divinyl ethers. The PA-conjugates released both drugs under acidic conditions, such as those found in the tumor microenvironment, endosomes, or lysosomes, while remaining stable at neutral pH 7.4. The drug ratio was optimized to achieve anticancer drug synergism with elevated cytotoxicity against LNCaP-hormone-dependent human PCa cells conferred via the induction of S phase cell cycle arrest by the upregulation of p53 and CDK inhibitors p21Waf/CIP1 and downregulation of cyclin D1. The application of rationally designed PA-Curc-DES combination conjugates represents a potentially exciting new treatment for prostate cancer.


Subject(s)
Acetals/chemistry , Antineoplastic Agents , Curcumin/chemistry , Diethylstilbestrol/chemistry , Polymers/chemistry , Prostatic Neoplasms/drug therapy , S Phase Cell Cycle Checkpoints/drug effects , Antineoplastic Agents/chemical synthesis , Antineoplastic Agents/chemistry , Antineoplastic Agents/pharmacokinetics , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Delayed-Action Preparations/chemical synthesis , Delayed-Action Preparations/chemistry , Delayed-Action Preparations/pharmacokinetics , Delayed-Action Preparations/pharmacology , Humans , Male , Neoplasm Proteins/metabolism , Prostatic Neoplasms/metabolism , Prostatic Neoplasms/pathology
13.
Eur Heart J ; 39(32): 2959-2971, 2018 08 21.
Article in English | MEDLINE | ID: mdl-29659797

ABSTRACT

Aim: The primary objective was to compare apixaban to heparin/vitamin K antagonist (VKA) in patients with atrial fibrillation (AF) and ≤48 h anticoagulation prior to randomization undergoing cardioversion. Methods: One thousand five hundred patients were randomized. The apixaban dose of 5 mg b.i.d. was reduced to 2.5 mg b.i.d. in patients with two of the following: age ≥ 80 years, weight ≤ 60 kg, or serum creatinine ≥ 133 µmol/L. To expedite cardioversion, at the discretion of the investigator, imaging and/or a loading dose of 10 mg (down-titrated to 5 mg) was allowed. The endpoints for efficacy were stroke, systemic embolism (SE), and death. The endpoints for safety were major bleeding and clinically relevant non-major (CRNM) bleeding. Results: There were 1038 active and 300 spontaneous cardioversions; 162 patients were not cardioverted. Imaging was performed in 855 patients, and 342 received a loading dose of apixaban. Comparing apixaban to heparin/VKA in the full analysis set, there were 0/753 vs. 6/747 strokes [relative risk (RR) 0; 95% confidence interval (95% CI) 0-0.64; nominal P = 0.015], no SE, and 2 vs. 1 deaths (RR 1.98; 95% CI 0.19-54.00; nominal P > 0.999). In the safety population, there were 3/735 vs. 6/721 major (RR 0.49; 95% CI 0.10-2.07; nominal P = 0.338) and 11 vs. 13 CRNM bleeding events (RR 0.83; 95% CI 0.34-1.89; nominal P = 0.685). On imaging, 60/61 with thrombi continued randomized treatment; all (61) were without outcome events. Conclusions: Rates of strokes, systemic emboli, deaths, and bleeds were low for both apixaban and heparin/VKA treated AF patients undergoing cardioversion. Clinical Trials.gov number: NCT02100228.


Subject(s)
Anticoagulants/therapeutic use , Atrial Fibrillation/therapy , Electric Countershock , Heparin/therapeutic use , Pyrazoles/therapeutic use , Pyridones/therapeutic use , Vitamin K/antagonists & inhibitors , Aged , Anticoagulants/adverse effects , Atrial Fibrillation/complications , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/mortality , Cause of Death , Drug Administration Schedule , Echocardiography, Transesophageal , Embolism/prevention & control , Female , Hemorrhage/chemically induced , Hemorrhage/prevention & control , Heparin/adverse effects , Humans , Male , Middle Aged , Pyrazoles/administration & dosage , Pyrazoles/adverse effects , Pyridones/administration & dosage , Pyridones/adverse effects , Stroke/prevention & control , Tomography, X-Ray Computed , Treatment Outcome
14.
J Child Adolesc Psychopharmacol ; 28(1): 55-65, 2018 02.
Article in English | MEDLINE | ID: mdl-29185786

ABSTRACT

OBJECTIVE: To evaluate the short-term efficacy and safety of desvenlafaxine versus placebo in the treatment of children and adolescents with major depressive disorder (MDD). METHODS: Outpatient children (7-11 years) and adolescents (12-17 years) who met DSM-IV-TR criteria for MDD and had screening and baseline Children's Depression Rating Scale-Revised (CDRS-R) total scores >40 were randomly assigned to 8 weeks of treatment with placebo, low exposure desvenlafaxine (20, 30, or 35 mg/day based on baseline weight), or higher exposure desvenlafaxine (25, 35, or 50 mg/day based on baseline weight). The primary efficacy endpoint was change from baseline in CDRS-R total score at week 8, analyzed using a mixed-effects model for repeated measures. Secondary efficacy assessments included Clinical Global Impressions-Severity and Clinical Global Impressions-Improvement scales. Safety assessments included adverse events and the Columbia-Suicide Severity Rating Scale. RESULTS: The safety population included 363 patients (children, n = 109; adolescents, n = 254). No statistical separation from placebo was observed for either desvenlafaxine group for CDRS-R total score or for any secondary efficacy endpoint. At week 8, adjusted mean (standard error) changes from baseline in CDRS-R total score for the desvenlafaxine low exposure, desvenlafaxine high exposure, and placebo groups were -23.7 (1.1), -24.4 (1.1), and -22.9 (1.1), respectively. The incidence of adverse events was similar among groups. CONCLUSION: Low and high exposure desvenlafaxine groups did not demonstrate efficacy for the treatment of MDD in children and adolescents in this double-blind, placebo-controlled trial. Desvenlafaxine (20-50 mg/day) was generally safe and well tolerated with no new safety signals identified in pediatric patients with MDD in this study.


Subject(s)
Antidepressive Agents/administration & dosage , Depressive Disorder, Major/drug therapy , Desvenlafaxine Succinate/administration & dosage , Adolescent , Antidepressive Agents/adverse effects , Child , Depressive Disorder, Major/physiopathology , Desvenlafaxine Succinate/adverse effects , Dose-Response Relationship, Drug , Double-Blind Method , Female , Humans , Male , Psychiatric Status Rating Scales , Treatment Outcome
15.
J Child Adolesc Psychopharmacol ; 28(1): 36-46, 2018 02.
Article in English | MEDLINE | ID: mdl-29189044

ABSTRACT

OBJECTIVES: To evaluate the short-term efficacy and safety of desvenlafaxine (25-50 mg/d) compared with placebo in children and adolescents with major depressive disorder (MDD). METHODS: Outpatient children (7-11 years) and adolescents (12-17 years) who met DSM-IV-TR criteria for MDD and had screening and baseline Children's Depression Rating Scale-Revised (CDRS-R) total scores >40 were randomly assigned to 8-week treatment with placebo, desvenlafaxine (25, 35, or 50 mg/d based on baseline weight), or fluoxetine (20 mg/d). The primary efficacy endpoint was change from baseline in CDRS-R total score at week 8, analyzed using a mixed-effects model for repeated measures. Secondary efficacy endpoints included week 8 Clinical Global Impressions-Severity, Clinical Global Impressions-Improvement (CGI-I), and response (CGI-I ≤ 2). Safety assessments included adverse events, physical and vital sign measurements, laboratory evaluations, electrocardiogram, and the Columbia-Suicide Severity Rating Scale. RESULTS: The safety population included 339 patients (children, n = 130; adolescents, n = 209). The primary endpoint, change from baseline in CDRS-R total score at week 8, did not statistically separate from placebo, for either desvenlafaxine (adjusted mean [standard error] change, -22.6 [1.17]) or fluoxetine (-24.8 [1.17]; placebo, -23.1 [1.18]). Week 8 CGI-I response rates were significantly greater for fluoxetine (78.2%; p = 0.017) than for placebo (62.6%); desvenlafaxine (68.7%) did not differ from placebo. Other secondary outcomes were consistent with those obtained with CDRS-R. Rates of treatment-emergent adverse events were comparable among treatment groups (desvenlafaxine, 60.0%; placebo, 70.5%; and fluoxetine, 64.3%). CONCLUSION: Desvenlafaxine did not demonstrate efficacy for treating MDD in children and adolescents in this trial. Because neither desvenlafaxine nor the reference medication, fluoxetine, demonstrated a statistically significant difference from placebo on the primary endpoint, this was considered a failed trial and no efficacy conclusions can be drawn. Desvenlafaxine 25-50 mg/d was generally safe and well tolerated in children and adolescents in this study.


Subject(s)
Antidepressive Agents/administration & dosage , Depressive Disorder, Major/drug therapy , Desvenlafaxine Succinate/administration & dosage , Fluoxetine/administration & dosage , Adolescent , Antidepressive Agents/adverse effects , Child , Depressive Disorder, Major/physiopathology , Desvenlafaxine Succinate/adverse effects , Dose-Response Relationship, Drug , Double-Blind Method , Female , Fluoxetine/adverse effects , Humans , Male , Psychiatric Status Rating Scales , Severity of Illness Index , Treatment Outcome
16.
Pediatr Surg Int ; 33(7): 747-754, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28516189

ABSTRACT

PURPOSE: Screening investigations for the vertebral, anorectal, cardiac, tracheo-oesophageal, renal and limb (VACTERL) association form an important part of the management of neonates with anorectal malformations (ARMs). We developed a proforma to define investigations and indications for referral. The aim of the current study was to determine if the proforma could improve screening rigour. METHODS: Four centres performed a 3-year retrospective audit of neonates with ARM. Following introduction of a proforma, the same data were collected prospectively for consecutive neonates over a further 2 years. The appropriate investigation of each component of the VACTERL association and the corresponding referral required for each abnormal result were defined. The proportion of patients undergoing appropriate investigation and referral was compared against these standards. An audit standard of 90% was set for each criteria. RESULTS: Prior to implementation of the proforma, 86 patients were audited, with a further 69 patients after. The audit standard was met in 7 criteria before introduction of the proforma in comparison to 10 criteria afterwards. CONCLUSION: The completeness of VACTERL screening and its documentation improved following introduction of the proforma. Performance remains imperfect. Review of specific criteria (such as definition of vertebral body screening) will help address this.


Subject(s)
Anal Canal/abnormalities , Anorectal Malformations/epidemiology , Clinical Audit , Esophagus/abnormalities , Heart Defects, Congenital/diagnosis , Kidney/abnormalities , Limb Deformities, Congenital/diagnosis , Neonatal Screening , Referral and Consultation , Spine/abnormalities , Trachea/abnormalities , Humans , Infant, Newborn , Prospective Studies , Retrospective Studies
17.
J Control Release ; 247: 73-85, 2017 02 10.
Article in English | MEDLINE | ID: mdl-28043863

ABSTRACT

Irinotecan is used clinically for the treatment of colorectal cancer; however, its utility is limited by its narrow therapeutic index. We describe the use of a generation 5 l-lysine dendrimer that has been part-modified with a polyoxazoline as a drug delivery vehicle for improving the therapeutic index of SN-38, the active metabolite of irinotecan. By conjugating SN-38 to the dendrimer via different linker technologies we sought to vary the release rate of the drug to generate diverse pharmacokinetic profiles. Three conjugates with plasma release half-lives of 2.5h, 21h, and 72h were tested for efficacy and toxicity using a mouse SW620 xenograft model. In this model, the linker with a plasma release half-life of 21h achieved sustained SN-38 exposure in blood, above the target concentration. Control over the release rate of the drug from the linker, combined with prolonged circulation of the dendrimer, enabled administration of an efficacious dose of SN-38, achieving significant regression of the SW620 tumours. The conjugates with 2.5 and 72h release half-lives did not achieve an anti-tumour effect. Intraperitoneal dosing of the clinically used prodrug irinotecan produces high initial and local concentrations of SN-38, which are associated with gastrointestinal toxicity. Administration of the 21h release dendrimer conjugate did not produce a high initial Cmax of SN-38. Consequently, a marked reduction in gastrointestinal toxicity was observed relative to irinotecan treatment. Additional studies investigating the dose concentrations and dose scheduling showed that a weekly dosing schedule of 4mg SN-38/kg was the most efficacious regimen. After 4 doses at weekly intervals, the survival period of the mice extended beyond 70 days following the final dose. These extensive studies have allowed us to identify a linker, dose and dosing regimen for SN-38 conjugated to polyoxazoline-modified dendrimer that maximised efficacy and minimised adverse side effects.


Subject(s)
Antineoplastic Agents, Phytogenic/administration & dosage , Camptothecin/analogs & derivatives , Colorectal Neoplasms/drug therapy , Delayed-Action Preparations/chemistry , Dendrimers/chemistry , Animals , Antineoplastic Agents, Phytogenic/adverse effects , Antineoplastic Agents, Phytogenic/pharmacokinetics , Antineoplastic Agents, Phytogenic/therapeutic use , Camptothecin/administration & dosage , Camptothecin/adverse effects , Camptothecin/pharmacokinetics , Camptothecin/therapeutic use , Colon/drug effects , Colon/pathology , Colorectal Neoplasms/pathology , Female , Irinotecan , Mice , Mice, Nude , Oxazoles/chemistry , Rats, Wistar , Rectum/drug effects , Rectum/pathology
18.
Biomaterials ; 113: 18-30, 2017 01.
Article in English | MEDLINE | ID: mdl-27810639

ABSTRACT

Spinal cord injury (SCI) suffers from a lack of effective therapeutic strategies. Animal models of acute SCI have provided evidence that transplantation of ependymal stem/progenitor cells of the spinal cord (epSPCs) induces functional recovery, while systemic administration of the anti-inflammatory curcumin provides neuroprotection. However, functional recovery from chronic stage SCI requires additional enhancements in available therapeutic strategies. Herein, we report on a combination treatment for SCI using epSPCs and a pH-responsive polymer-curcumin conjugate. The incorporation of curcumin in a pH-responsive polymeric carrier mainchain, a polyacetal (PA), enhances blood bioavailability, stability, and provides a means for highly localized delivery. We find that PA-curcumin enhances neuroprotection, increases axonal growth, and can improve functional recovery in acute SCI. However, when combined with epSPCs, PA-curcumin also enhances functional recovery in a rodent model of chronic SCI. This suggests that combination therapy may be an exciting new therapeutic option for the treatment of chronic SCI in humans.


Subject(s)
Acetals/chemistry , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Curcumin/therapeutic use , Delayed-Action Preparations/chemistry , Polymers/chemistry , Spinal Cord Injuries/therapy , Spinal Cord/drug effects , Stem Cell Transplantation , Animals , Anti-Inflammatory Agents, Non-Steroidal/administration & dosage , Anti-Inflammatory Agents, Non-Steroidal/chemistry , Cells, Cultured , Curcumin/administration & dosage , Curcumin/chemistry , Female , Neuroprotective Agents/administration & dosage , Neuroprotective Agents/chemistry , Neuroprotective Agents/therapeutic use , Rats, Sprague-Dawley , Recovery of Function , Spinal Cord/physiopathology , Spinal Cord Injuries/physiopathology , Stem Cell Transplantation/methods
19.
Notes Rec R Soc Lond ; 71(4): 371-384, 2017 Dec 20.
Article in English | MEDLINE | ID: mdl-31390398

ABSTRACT

In mid July 1860, the Athenaeum published a summary of the discussions about Charles Darwin's theory that took place at the British Association meeting in Oxford. Its account omitted the famous exchange between Samuel Wilberforce, Bishop of Oxford, and Thomas Huxley, the rising man of science. A fuller report of the meeting was published a week later in a local weekly, the Oxford Chronicle, but this has gone unnoticed by historians. The Oxford Chronicle supplies a new version of Wilberforce's question to Huxley, with more material about religious objections to human evolution and the proper role of authority in popular scientific discussions. Excerpts from the Athenaeum and Oxford Chronicle accounts show that they likely had a common ancestor, and other sources corroborate details given only in the Oxford Chronicle. This discovery reveals that the Athenaeum narrative-until now the longest and best known-was censored to remove material that was considered objectionable. The Oxford Chronicle gives us a fuller story of what was said and how the audience reacted to the encounter between Huxley and Wilberforce.

20.
Mol Pharm ; 12(10): 3639-49, 2015 Oct 05.
Article in English | MEDLINE | ID: mdl-26355563

ABSTRACT

There is a need to develop new and innovative polymer carriers to be used as drug delivery systems and/or imaging agents owing to the fact that there is no universal polymeric system that can be used in the treatment of all diseases. Additionally, limitations with existing systems, such as a lack of biodegradability and biocompatibility, inevitably lead to side effects and poor patient compliance. New polymer therapeutics based on amino acids are excellent candidates for drug delivery, as they do not suffer from these limitations. This article reports on a simple yet powerful methodology for the synthesis of 3-arm star-shaped polyglutamic acid with well-defined structures, precise molecular weights (MW), and low polydispersity (D = <1.3). These were synthesized by ring-opening polymerization (ROP) of N-carboxyanhydrides (NCA) in a divergent method from novel multifunctional initiators. Herein, their exhaustive physicochemical characterization is presented. Furthermore, preliminary in vitro evaluation in selected cell models, and exhaustive in vivo biodistribution and pharmacokinetics, highlighted the advantages of these branched systems when compared with their linear counterparts in terms of cell uptake enhancement and prolonged plasma half-life.


Subject(s)
Drug Delivery Systems/methods , Polyglutamic Acid/analogs & derivatives , Cell Line, Tumor/metabolism , Circular Dichroism , Endothelial Cells/metabolism , Flow Cytometry , Humans , In Vitro Techniques , Microscopy, Confocal , Molecular Structure , Polyglutamic Acid/chemical synthesis , Polyglutamic Acid/chemistry , Polyglutamic Acid/pharmacokinetics , Polymerization , Umbilical Veins/cytology , Umbilical Veins/metabolism
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