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Polymeric Nanoparticles (polymeric + nanoparticle)
Selected AbstractsControlled size chitosan nanoparticles as an efficient, biocompatible oligonucleotides delivery systemJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Romila Manchanda Abstract Polymeric nanoparticles of chitosan crosslinked with glutaraldehyde have been prepared using reverse micellar system. An optically clear solution was obtained on redispersing these nanoparticles in aqueous buffer. The nanoparticles were characterized for their size and surface morphology employing dynamic laser scattering (DLS) and transmission electron microscopy (TEM). The TEM images showed spherical particles with smooth surface and narrow size distribution of about 90 nm, which was also supported by DLS data. Size and morphology of the particles remains the same on redispersing the lyophilized powder of these nanoparticles in aqueous buffer. Further, these nanoparticles were loaded with different synthetic oligonucleotides (ODNs). In vitro pH dependent release of the adsorbed oligonucleotides from these nanoparticles was also studied. At basic pH the release of oligonucleotides was found higher as compared with neutral and acidic medium. Cytotoxicity studies done on HEK 293 cells reveals that oligonucleotide loaded nanoparticles have high cell viability of nearly 76,88% whereas those of lipofectamine was about 35%. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Doxorubicin-Conjugated Immuno-Nanoparticles for Intracellular Anticancer Drug DeliveryADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Meng Shi Abstract A polymeric nanoparticle comprised of surface furan groups is used to bind, by Diels,Alder (DA) coupling chemistry, both targeting anti-human epidermal growth factor receptor 2 (anti-HER2) antibodies and chemotherapeutic doxorubicin (DOX) for targeted, intracellular delivery of DOX. In this new approach for delivery, where both chemotherapeutic and targeting ligand are attached, for the first time, to the surface of the delivery vehicle, the nuclear localization of DOX in HER2-overexpressing breast cancer SKBR-3 cells is demonstrated, as determined by confocal laser scanning microscopy. Flow cytometric analysis shows that the conjugated DOX maintains its biological function and induces similar apoptotic progression in SKBR-3 cells as free DOX. The viable cell counts of SKBR-3 cancer cells following incubation with different nanoparticle formulations demonstrates that the combined DOX and anti-HER2 nanoparticle is more efficacious than the nanoparticle formulation with either DOX or anti-HER2 alone. While free DOX shows similar cytotoxicity against both cancerous SKBR-3 cells and healthy HMEC-1 cells, the combined DOX-anti-HER2 nanoparticle is significantly more cytotoxic against SKBR-3 cells than HMEC-1 cells, suggesting the benefit of nanoparticle-conjugated DOX for cell type-specific targeting. The DOX-conjugated immuno-nanoparticle represents an entirely new method for localized co-delivery of chemotherapeutics and antibodies. [source] Anticancer Drug Delivery: Doxorubicin-Conjugated Immuno-Nanoparticles for Intracellular Anticancer Drug Delivery (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 11 2009Mater. Self-assembled polymeric nanoparticles of the amphiphilic copolymer poly(TMCC-co-LA)-g-PEG-furan can couple both anti-HER2 antibodies and chemotherapeutic doxorubicin (DOX) on their surfaces, report Molly Shoichet and co-workers on page 1689. This novel strategy selectively delivers DOX to the cell nucleus of HER2-overexpressing breast cancer cells while maintaining the pharmaceutical toxicity of DOX, paving the way to targeted drug delivery in breast cancer treatment. [source] A Versatile "Click" Chemistry Precursor of Functional Polystyrene NanoparticlesADVANCED MATERIALS, Issue 28 2010Lorea Oria The synthesis of a versatile "click" chemistry precursor of functional polystyrene nanoparticles is reported. The resulting nanoparticles thereof offer inherent characteristics of ultrasmall polymeric nanoparticles (size ,4 nm) plus interesting functionalization possibilities, opening the door to new hybrid, soft nano-objects, bridging the gap between synthetic and natural polymers. [source] Smart Drug-Loaded Polymer Gold Nanoshells for Systemic and Localized Therapy of Human Epithelial CancerADVANCED MATERIALS, Issue 43 2009Jaemoon Yang Near-infrared-light-sensitive multifunctional smart drug-loaded polymer gold nanoshells are fabricated as advanced prototypes, composed of chemotherapeutic agents (therapeutic antibody and anticancer drug-loaded polymeric nanoparticles) for systemic chemotherapy of human epithelial cancer and a polymer-based gold nanoshell for localized photothermal treatment by NIR light. [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] Poly(,-glutamic acid) nanoparticles as an efficient antigen delivery and adjuvant system: Potential for an AIDS vaccineJOURNAL OF MEDICAL VIROLOGY, Issue 1 2008Xin Wang Abstract Antigen delivery systems using polymeric nanoparticles are of special interest as stable protein-based antigen carriers. In the present study, novel biodegradable poly(,-glutamic acid) (,-PGA) nanoparticles were examined for their antigen delivery and immunostimulatory activities in vitro and in vivo. The uptake of ovalbumin by dendritic cells was markedly enhanced by ,-PGA nanoparticles, and the ovalbumin was gradually released from ,-PGA nanoparticles into the cells. In addition, ,-PGA nanoparticles appeared to have great potential as an adjuvant, because they could induce the maturation of dendritic cells. Although not only ovalbumin-encapsulating nanoparticles (OVA-NPs) but also a simple mixture of ovalbumin and nanoparticles induced dendritic cell maturation, the only dendritic cells exposed to OVA-NPs could strongly activate antigen-specific interferon (IFN)-,-producing T cells. Subcutaneous immunization of mice with human immunodeficiency virus type 1 (HIV-1) p24-encapsulating nanoparticles activated antigen-specific IFN-,-producing T cells in spleen cells and induced p24-specific serum antibodies, as compared to immunization with p24 alone. Like ovalbumin, a mixture of p24 and nanoparticles also induced antigen-specific serum antibodies but did not activate IFN-,-producing T cells in spleen cells, suggesting that nanoparticles play a critical role in inducing cellular immune responses. Furthermore, ,-PGA nanoparticles had a capacity comparable to that of the complete Freund's adjuvant (CFA) in inducing p24-specific serum antibody. However, unlike CFA, they predominantly activated p24-specific IFN-,-producing T cells. Thus, ,-PGA nanoparticles encapsulating various antigens may have great potential as novel and efficient protein-based vaccines against infectious diseases, including HIV-1 infection. J. Med. Virol. 80:11,19, 2008. © 2007 Wiley-Liss, Inc. [source] From polymeric particles to multifunctional nanocapsules for biomedical applications using the miniemulsion processJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 3 2010Katharina Landfester Abstract The miniemulsions process represents a versatile tool for the formation of polymeric nanoparticles consisting of different kinds of polymer as obtained by a variety of polymerization types ranging from radical, anionic, cationic, enzymatic polymerization to polyaddition, and polycondensation. The process perfectly allows the encapsulation of hydrophilic and hydrophobic liquids and solids in polymeric shells, molecularly dissolved dyes or other components. In combination with a specific functionalization of the nanoparticles' or nanocapsules' surfaces and the possibility to release substances in a defined way from the interior, complex nanoparticles or nanocapsules are obtained, which are ideally suited for application in biomedical application as marker and targeted drug-delivery system. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 493,515, 2010 [source] Microstructure Formation and Property of Chitosan-Poly(acrylic acid) Nanoparticles Prepared by Macromolecular ComplexMACROMOLECULAR BIOSCIENCE, Issue 10 2005Qi Chen Abstract Summary: We report here a study on the microstructure formation process of polymeric nanoparticles based on polyelectrolyte complexes. When polyanion poly(acrylic acid) (PAA) was dropped into polycation chitosan (CS) solution, CS-PAA nanoparticles with diverse microstructure would be formed under different experimental conditions. The microstructure of CS-PAA nanoparticles changed from solid spherical nanoparticles to core-shell separative ones and turned back to solid spherical ones with the variation of preparation conditions. The influence of molecular weight of CS and PAA, shell cross-linking, dropping temperature on the size, stability and morphology of CS-PAA nanoparticles were also studied. The nanoparticle size was affected by the molecular weight of CS and PAA, the ratio of amino group to carboxyl group (na/nc) and the incubation temperature as well. The shell-cross-linking provides a means to stabilize these nanoparticles. These nanoparticles can encapsulate plasmid DNA very well, which makes them have great potential in gene delivery. Microstructure of non-cross-linked CS-PAA nanoparticles, encapsulated plasmid DNA, at various na/nc. [source] Intramolecular Click Cycloaddition: An Efficient Room-Temperature Route towards Bioconjugable Polymeric NanoparticlesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 12-13 2008Alaitz Ruiz de Luzuriaga Abstract A highly efficient room-temperature synthetic route to bioconjugable polymeric nanoparticles in the 5,20 nm size range based on single-chain intramolecular click cycloaddition is described. It is illustrated by preparing single-chain cross-linked polymeric NPs from poly[MMA- co -(3-azidopropyl methacrylate)- co -(3-trimethylsilyl-propyn-1-yl methacrylate)] terpolymers using a one-pot procedure and a continuous addition technique. For polymeric NPs with an excess of azide groups, aminoacid/PMMA NPs were easily obtained by performing a second click reaction with propargyl glycine. This versatile and general method opens the way to the synthesis of other kinds of polymeric and bioconjugated NPs beyond those reported in this communication. [source] HER-2-Targeted Nanoparticle,Affibody Bioconjugates for Cancer TherapyCHEMMEDCHEM, Issue 12 2008Frank Alexis Dr. Affibodies are a class of polypeptide ligand that are potential candidates for tissue-specific targeting of drug-encapsulated controlled release polymeric nanoparticles (NPs). We developed drug delivery vehicles composed of polymeric NPs surface modified with affibody ligands that bind the extracellular domain of the human epidermal growth factor receptor,2 (HER-2) for targeted delivery to cells that overexpress the HER-2 antigen. [source] | ||||||||||||||||||||||