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Specific Delivery (specific + delivery)
Selected AbstractsN -Malonyl-1,2-dihydroisoquinoline as a Novel Carrier for Specific Delivery of Drugs to the BrainARCHIV DER PHARMAZIE, Issue 1 2010Mohamed Abdel-Aziz Abstract N -Malonyl-1,2-dihydroisoquinoline derivatives were synthesized and investigated as a novel carrier system for site-specific and sustained delivery of drugs to the brain. Such carriers are expected to be stable against air oxidation due to the presence of the carbonyl group close to nitrogen of the dihydroisoquinoline. Reduction of the prepared isoquinolinium quaternary derivatives with sodium dithionite afforded a novel group of N -malonyl-1,2-dihydroisoquinoline chemical delivery systems (CDS). The synthesized N -malonyl-1,2-dihydroisoquinoline chemical delivery systems were subjected to various chemical and biological investigations to evaluate their ability to cross the blood-brain barrier (BBB), and to be oxidized biologically into their corresponding quaternary derivatives. The in-vitro oxidation studies showed that the designed N -malonyl-1,2-dihydroisoquinoline chemical delivery system could be oxidized into its corresponding quaternary derivatives at an adequate rate. The in-vivo distribution studies showed that these N -malonyl-1,2-dihydroisoquinoline chemical delivery systems were able to cross the blood-brain barrier at detectable concentrations. [source] Sustained delivery and efficacy of polymeric nanoparticles containing osteopontin and bone sialoprotein antisenses in rats with breast cancer bone metastasisINTERNATIONAL JOURNAL OF CANCER, Issue 7 2010Victoria Elazar Abstract Poor prognosis in mammary carcinoma is associated with a certain expression profile of a defined set of genes including osteopontin and bone sialoprotein. Efficient and specific delivery of antisenses (AS) and a protection of the sequences from degradation are the crucial conditions for AS therapeutic efficiency. We hypothesized that effective and safe AS delivery direceted against these genes could be achieved by polymeric nanoparticles (NP) fabricated from a biocompatible polymer. Due to their nano-size range and small negative charge, AS-NP can overcome the absorption barrier offering increased resistance to nuclease degradation, sustained duration of AS administration, and consequently, prolonged antisense action. The ASs designed against OPN and BSP-II were successfully encapsulated in NP composed of the biodegradable and biocompatible polylactide- co -glycolide polymer (PLGA), exhibiting sustained release and stability of the ASs. The therapeutic efficacy of the AS-NP delivery system was examined in vitro, and in a breast cancer bone metastasis animal model of MDA-MB-231 human breast cancer cells in nude rats. Treatment with OPN-AS or BSP-AS loaded NP in comparison with osmotic mini-pumps (locoregional injection and SC implants, respectively) resulted in a significant decrease in both, tumor bone metastasis incidence and in the size of the lesions in rats with metastases. Despite its smaller dose, AS-NP exhibited a better therapeutic efficacy than osmotic mini-pumps in terms of lesion ratio at later time periods (8,12 weeks). It may be concluded that AS delivery by NP is a promising therapeutic modality providing stability of the encapsulated AS and a sustained release. [source] Targeted therapy of renal cell carcinoma: Synergistic activity of cG250-TNF and IFNgINTERNATIONAL JOURNAL OF CANCER, Issue 1 2009Stefan Bauer Abstract Immunotherapeutic targeting of G250/Carbonic anhydrase IX (CA-IX) represents a promising strategy for treatment of renal cell carcinoma (RCC). The well characterized human-mouse chimeric G250 (cG250) antibody has been shown in human studies to specifically enrich in CA-IX positive tumors and was chosen as a carrier for site specific delivery of TNF in form of our IgG-TNF-fusion protein (cG250-TNF) to RCC xenografts. Genetically engineered TNF constructs were designed as CH2/CH3 truncated cG250-TNF fusion proteins and eucariotic expression was optimized under serum-free conditions. In-vitro characterization of cG250-TNF comprised biochemical analysis and bioactivity assays, alone and in combination with Interferon-, (IFN,). Biodistribution data on radiolabeled [125J] cG250-TNF and antitumor activity of cG250-TNF, alone and in combination with IFN,, were measured on RCC xenografts in BALB/c nu/nu mice. Combined administration of cG250-TNF and IFN, caused synergistic biological effects that represent key mechanisms displaying antitumor responses. Biodistribution studies demonstrated specific accumulation and retention of cG250-TNF at CA-IX-positive RCC resulting in growth inhibition of RCC and improved progression free survival and overall survival. Antitumor activity induced by targeted TNF-based constructs could be enhanced by coadministration of low doses of nontargeted IFN, without significant increase in side effects. Administration of cG250-TNF and IFN, resulted in significant synergistic tumoricidal activity. Considering the poor outcome of renal cancer patients with advanced disease, cG250-TNF-based immunotherapeutic approaches warrant clinical evaluation. © 2009 UICC [source] Innovations in oligonucleotide drug deliveryJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 8 2003Melanie A. Lysik Abstract Oligonucleotides (ONs) are a new class of therapeutic compounds under investigation for the treatment of a variety of disease states, such as cancer and HIV, and for FDA approval of an anti-CMV retinitis antisense molecule (VitraveneÔ, Isis Pharmaceuticals). However, these molecules are limited not only by poor cellular uptake, but also by a general lack of understanding regarding the mechanism(s) of ON cellular uptake. As a result, various delivery vehicles have been developed that circumvent the proposed mechanism of uptake, endocytosis, while improving target specific delivery and/or drug stability. This review describes various traditional and novel delivery mechanisms that have been employed to improve ON cellular delivery, cost effectiveness, and therapeutic efficacy. © 2003 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 92:1559,1573, 2003 [source] In vitro targeted photodynamic therapy with a pyropheophorbide-a conjugated inhibitor of prostate-specific membrane antigenTHE PROSTATE, Issue 6 2009Tiancheng Liu Abstract BACKGROUND The lack of specific delivery of photosensitizers (PSs), represents a significant limitation of photodynamic therapy (PDT) of cancer. The biomarker prostate-specific membrane antigen (PSMA) has attracted considerable attention as a target for imaging and therapeutic applications for prostate cancer. Although recent efforts have been made to conjugate inhibitors of PSMA with imaging agents, there have been no reports on PS-conjugated PSMA inhibitors for targeted PDT of prostate cancer. The present study focuses on the use of a PSMA inhibitor-conjugate of pyropheophorbide-a (Ppa-conjugate 2) for targeted PDT to achieve apoptosis in PSMA+ LNCaP cells. METHODS Confocal laser scanning microscopy with a combination of nuclear staining and immunofluorescence methods were employed to monitor the specific imaging and PDT-mediated apoptotic effects on PSMA-positive LNCaP and PSMA-negative (PC-3) cells. RESULTS Our results demonstrated that PDT-mediated effects by Ppa-conjugate 2 were specific to LNCaP cells, but not PC-3 cells. Cell permeability was detected as early as 2 hr by HOE33342/PI double staining, becoming more intense by 4 hr. Evidence for the apoptotic caspase cascade being activated was based on the appearance of poly-ADP-ribose polymerase (PARP) p85 fragment. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay detected DNA fragmentation 16 hr post-PDT, confirming apoptotic events. CONCLUSIONS Cell permeability by HOE33342/PI double staining as well as PARP p85 fragment and TUNEL assays confirm cellular apoptosis in PSMA+ cells when treated with PS-inhibitor conjugate 2 and subsequently irradiated. It is expected that the PSMA targeting small-molecule of this conjugate can serve as a delivery vehicle for PDT and other therapeutic applications for prostate cancer. Prostate 69:585,594, 2009. © 2009 Wiley-Liss, Inc. [source] | |||||||||||||