Development of a novel approach for brain delivery : dendritic nanocarriers for the enhanced delivery of methotrexate to the brain tumors

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Development of a novel approach for brain delivery : dendritic nanocarriers for the enhanced delivery of methotrexate to the brain tumors

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Cationic Bovine Serum Albumin (CBA) conjugated Poly Lactic-co-Glycolic Acid (PLGA) nanoparticles for extended delivery of methotrexate into brain tumor

Current treatment strategies for the treatment of brain tumor have been hindered primarily by the presence of highly lipophilic insurmountable blood-brain barrier (BBB). The purpose of current research was to investigate the efficiency of engineered biocompatible polymeric nanoparticles (NPs) as drug delivery vehicle to bypass the BBB and enhance biopharmaceutical attributes of anti-metabolite methotrexate (MTX) encapsulated NPs. The NPs were prepared by solvent diffusion method using cationic bovine serum albumin (CBA), and characterized for physicochemical parameters such as particle size, polydispersity index, and zeta-potential; while the surface modification was confirmed by FTIR, and NMR spectroscopy. Developed NPs exhibited zestful relocation of FITC tagged NPs across BBB in albino rats. Further, hemolytic studies confirmed them to be non-toxic and biocompatible as compared to free MTX. In vitro cytotoxicity assay of our engineered NPs on HNGC1 tumor cells proved superior uptake in tumor cells; and elicited potent cytotoxic effect as compared to plain NPs and free MTX solution. The outcomes of the study evidently indicate the prospective of CBA conjugated poly (D,L-lactide-co-glycolide) (PLGA) NPs loaded with MTX in brain cancer bomber with amplified capability to circumvent BBB.

Design and stability study of a paediatric oral solution of methotrexate 2mg/ml

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Methotrexate nanoparticle delivery system for treatment of inflammatory bowel disease in pediatric patients

Purpose: To evaluate the efficacy and safety of methotrexate (MTX) nanoparticles in pediatric patients with inflammatory bowel disease (IBD). Methods: In this randomized, open-label clinical study, 28 pediatric patients with moderate to severe IBD were randomly assigned to treatment (MTX nanoparticles,15 mg/week) or control (azathioprine, AZA, 2 mg/kg/day) group. Nanoparticles were synthesized by adding calcium chloride to sodium alginate solution containing MTX, and was further treated with poly-L-lysine aqueous solution. The nanoparticles were evaluated for particle size, zeta potential and drug encapsulation efficacy. Erythrocyte sedimentation rate, C-reactive protein, aspartate aminotransferase, alanine transaminase, and disease activity scores were used to assess IBD remission. Results: Nanoparticle size, zeta potential and encapsulation efficacy were 164.4 ± 6.9 nm, -32.6 ± 3.7 mV, and 97.8 ± 4.2 %, respectively. After 12 weeks of therapy, the mean Pediatric Crohn\'s Disease Activity Index (PCDAI) scores for control and treatment groups were 22.3 ± 2.14 and 16.8 ± 1.87, respectively, while mean Pediatric Ulcerative Colitis Activity (PUCAI) Index scores were 24.3 ± 1.47 and 18.7 ± 1.92, respectively. Eight patients in the treatment and five patients in the control group achieved remission. Biochemical parameters varied significantly between the groups. Conclusion: MTX nanoparticles are safe and more effective than standard first-line IBD therapy. However, further studies are required to determine the suitability of the formulation for therapeutic use.

Does the p38 MAP kinase inhibitor pamapimod have potential for the treatment of rheumatoid arthritis?

Background: Methotrexate alone or in combination with other agents is the standard treatment for moderate-to-severe rheumatoid arthritis. As the biological agents are expensive, they are not usually used until methotrexate has failed to give a good response. Thus, there is scope for the development of cheaper drugs that can be used instead of methotrexate or in addition to methotrexate. Objectives/methods: Pamapimod is a p38α inhibitor being developed for use in the treatment of rheumatoid arthritis. The objective was to evaluate the recent clinical trials of pamapimod in subjects with rheumatoid arthritis. Results: There is no clear cut evidence that pamapimod alone or in the presence of methotrexate is efficacious in subjects with rheumatoid arthritis, but it does cause adverse effects. Conclusion: It is unlikely that pamapimod will be useful in the treatment of rheumatoid arthritis.

Immunodeficiency-associated lymphomas

This article covers lymphoproliferative disorders in patients with primary or acquired immunodeficiencies. Primary immunodeficiences include Ataxia Telangiectasia and X-linked disorders such as Wiskott-Aldrich syndrome. Acquired immunodeficiencies predominantly occur in the setting of infection with the Human Immunodeficiency Virus or arise following immunosuppressive therapy administered after organ transplantation. The rising incidence of HIV throughout the world and the dramatic increase in transplant surgery since the 1990's suggest that these lymphomas will remain an important health problem. Evidence for lymphoma developing as a result of treatment with methotrexate or Tumour Necrosis Factor Antagonists for autoimmune entities will also be reviewed. The lymphoproliferations that occur with immunodeficiency are extremely heterogenous. In part this reflects the diversity of the causal immune defect. The most striking clinical characteristic is the high frequency of extranodal disease. Frequently, these lymphomas are driven by viruses such as Epstein-Barr virus (EBV), although the lack of EBV in a proportion indicates that alternate pathways must also be involved in the pathogenesis. Lastly, discussion will centre on mechanisms utilized by lymphomas in the immunodeficient as these may have applications to lymphomas in the "immunocompetent", by serving as a paradigm for the altered immunoregulatory environment present in many lymphoma sub-types.

Platinum-based chemotherapy in metastatic breast cancer : current status

Cisplatin and carboplatin are active in previously untreated patients with metastatic breast cancer (MBC) with mean response rates (RRs) of 50 and 32%, respectively. In pretreated patients the RR to cisplatin/carboplatin monotherapy declines markedly to <10%. Cisplatin and carboplatin have been combined with many other cytotoxics. In first-line setting high activity has been observed in combination with taxanes or vinorelbine (RRs consistently ∼60%). It appears that these newer combinations are superior to older regimens with etoposide (RRs 30 to 50%) or 5-fluorouracil (RRs 40 to 60%). Cisplatin-/carboplatin-based regimens with infusional 5-FU and epirubicin/paclitaxel/vinorelbine achieve high RRs of around 60 to 80%. However these regimens are difficult to administer in all patients because they require central venous access for continuous 5-FU infusion. In pretreated MBC the combinations of cisplatin-taxane/vinorelbine/gemcitabine or carboplatin-docetaxel/vinorelbine yield RRs of 40 to 50%, which are higher than those achieved with platinum-etoposide/5-FU. In locally advanced disease cisplatin-based regimens achieve very high RRs (>80%). This would suggest that in chemotherapy-naïve patients platinum-based therapy might have an important role to play. Additionally the synergy demonstrated between platinum compounds, taxanes and herceptin, in preclinical and clinical studies is of immense importance and the results of the two ongoing Breast Cancer International Research Group randomized phase III studies are eagerly awaited. These studies may help clarify the role of platinum compounds in the treatment of metastatic and possibly early breast cancer. © 2003 Elsevier Ltd. All rights reserved.

Platinum-based chemotherapy in metastatic breast cancer : the Leicester (UK) experience

Aims: After failure of anthracycline- and taxane-based chemotherapy in metastatic breast cancer, treatment options until recently were limited. Until the introduction of capecitabine and vinorelbine, no standard regimen was available. We conducted a retrospective study to determine the efficacy and toxicity of platinum-based chemotherapy in metastatic breast cancer. Materials and methods: Forty-two women with metastatic breast cancer previously treated with anthracyclines (93%) and/or taxanes (36%) received mitomycin-vinblastine-cisplatin (MVP) (n = 23), or cisplatin-etoposide (PE) (n = 19), as first-, second- and third-line treatment at a tertiary referral centre between 1997 and 2002. Chemotherapy was given every 3 weeks as follows: mitomycin-C (8 mg/m 2) (cycles 1, 2, 4, 6), vinblastine (6 mg/m 2), and cisplatin (50 mg/m 2) all on day 1; and cisplatin (75 mg/m 2) and etoposide (100 mg/m 2) on day 1 and (100 mg/m 2) orally twice a day on days 2-3. Results: The response rate for 40 evaluable patients (MVP: n = 23; PE: n = 17) was 18% (95% confidence interval [CI]: 9-32%). The response rate to MVP was 13% (95% CI: 5-32%, one complete and two partial responses) and to PE 24% (10-47%, four partial responses). Disease stabilised in 43% (26-63%) and 47% (26-69%) of women treated with MVP and PE, respectively. After a median follow-up of 18 months, 37 women (MVP: n = 19; PE: n = 18) died from their disease. Median (range) progression-free survival and overall survival were 6 months (0.4-18.7) and 9.9 months (1.3-40.8), respectively. Median progression-free survival for the MVP and PE groups was 5.5 and 6.2 months (Log-rank, P = 0.82), and median overall survival was 10.2 and 9.4 months (Log-rank, P = 0.46), respectively. The main toxicity was myelosuppression. Grades 3-4 neutropenia was more common in women treated with PE than in women treated with MVP (74% vs 30%; P = 0.012), but the incidence of neutropenic sepsis, relative to the number of chemotherapy cycles, was low (7% overall). The toxicity-related hospitalisation rate was 1.2 admissions per six cycles of chemotherapy. No treatment-related deaths occurred. MVP and PE chemotherapy have modest activity and are safe in women with metastatic breast cancer. © 2005 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

The role of chemotherapy in the treatment of adult soft tissue sarcomas

Adult soft tissue sarcomas are relatively rare tumours which are curable with radical surgery. Approximately 50% of patients will develop inoperable disease or metastases for which chemotherapy may be inappropriate. Only two cytotoxic agents - doxorubicin and ifosfamide - have activity in > 20% of patients. For both these agents there is evidence of a dose-response relationship. There is currently no good evidence that combination chemotherapy confers a clinical benefit compared with single agents. Outside a clinical trial, standard first-line therapy should be with single agent doxorubicin at a dose intensity ≥ 70 mg2 every 3 weeks. Approximately 25% of patients may be expected to respond to this regimen. There is the suggestion that responses may occur to ifosfamide in patients who progress on doxorubicin. The role of chemotherapy in the adjuvant setting remains uncertain. Several trials have suggested a modest relapse-free and overall survival benefit for the use of post-operative chemotherapy and a recent overview of 14 randomised trials confirms a small though significant benefit. These benefits have to be weighed against the toxicity of chemotherapy. The importance of treating all patients with soft tissue sarcomas in clinical trials is stressed. There is an urgent need to define new active agents to treat this disease.

Cisplatin and gemcitabine in the management of metastatic penile cancer

Penile cancer is rare and receives little public attention. There are few treatment options for advanced disease. The most active regimen to date is a combination of bleomycin, methotrexate, and cisplatin. However the treatment-related mortality is 11% and hence this combination has not been adapted as a standard of care. We report two cases of advanced penile cancer where a sustained palliative response was observed with combination chemotherapy using cisplatin and gemcitabine. Our experience demonstrates that this is a well tolerated regimen active in this setting. © 2009 Elsevier Inc. All rights reserved.