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Delivery Carriers (delivery + carrier)
Kinds of Delivery Carriers Selected AbstractsRadioevaluation of PAMs, CMs, and PS-Lip as an oral carrier for vaccine delivery into intestinal Peyer's patchesDRUG DEVELOPMENT RESEARCH, Issue 12 2006Chang-Moon Lee Abstract The aim of the present study was to evaluate the utility of pullulan acetate microparticles (PAMs), chitosan micropaticles (CMs), and dipalmitoylphosphatidyl-serine-liposomes (PS-Lip) as oral carriers for delivery to the intestinal Peyer's patches (PPs). To monitor PP delivery after oral administration, PAMs, CMs, and PS-Lip were radiolabeled with 99mTc. Radiolabeling efficiencies of the particles were 95±2.5% (PAMs), 87±4.3% (CMs), and 77.2±5.8% (PS-Lip). In delivery studies to the PPs, the percentage of PS-Lip taken up to the PPs was 3.8 × 10,3±0.3% of the administered dose with PS-Lip group showed significantly high uptake compared to the PAM and CM groups. These results suggest that PS-Lip may be used as a potential system for developing an oral delivery carrier. Drug Dev. Res. 67:884,889, 2006. © 2007 Wiley-Liss, Inc. [source] Brush-Like Amphoteric Poly[isobutylene- alt -(maleic acid)- graft -oligoethyleneamine)]/DNA Complexes for Efficient Gene TransfectionMACROMOLECULAR RAPID COMMUNICATIONS, Issue 13 2010Majad Khan Abstract Synthetic gene delivery vectors, especially cationic polymers have attracted enormous attention in recent decades because of their ease of manufacture, targettability, and scaling up. However, certain issues such as high cytotoxicity and low transfection efficiency problems have hampered the advance of nonviral gene delivery. In this study, we designed and synthesized brush-like amphoteric poly[isobutylene- alt -(maleic acid)- graft -oligoethyleneamine] capable of mediating highly efficient gene transfection. The polymers are composed of multiple pendant oligoethyleneimine molecules with alternating carboxylic acid moiety grafted onto poly[isobutylene- alt -(maleic anhydride)]. The polymer formed from pentaethylenehexamine {i.e., poly[isobutylene- alt -(maleic acid)- graft -pentaethylenehexamine)]} was able to condense DNA efficiently into nanoparticles of size around 200,nm with positive zeta potential of about 28,30,mV despite its amphoteric nature. Luciferase expression level and percentage of GFP expressing cells induced by this polymer was higher than those mediated with polyethyleneimine (branched, 25,kDa) by at least one order of magnitude at their optimal N/P ratios on HEK293, HepG2, and 4T1 cells. In vitro cytotoxicity testing revealed that the polymer/DNA complexes were less cytotoxic than those of PEI, and the viability of the cells after being incubated with the polymer/DNA complexes at the optimal N/P ratios was higher than 85%. This polymer can be a promising gene delivery carrier for gene therapy. [source] Chitosan-Pectin Composite Gel Spheres: Effect of Some Formulation Variables on Drug ReleaseMACROMOLECULAR SYMPOSIA, Issue 1 2004Pornsak Sriamornsak Abstract Chitosan-pectin composite gel spheres were prepared by ionotropic gelation method. Pectin solution containing indomethacin, a model drug, was extruded into a mixture of chitosan and calcium chloride. The release behavior of indomethacin from composite gel spheres was investigated in-vitro. The influence of factors affecting release behavior, such as type of pectin, molecular weight of chitosan, cross-linking time and release medium, were discussed in this study. Adding chitosan into gelation medium could retard the release of indomethacin from gel spheres. The different type of pectin used demonstrated slightly different drug release profiles. The higher molecular weight of chitosan showed less indomethacin release than the lower one. The increased cross-linking time slowed the drug release from composite gel spheres. The release of indomethacin from composite gel spheres was also dependent on the release medium. The drug release was slower in tris buffer where no phosphate ions which can induce the precipitation of calcium phosphate. The results suggested that the composite gel spheres of pectin and chitosan could be used as a controlled release drug delivery carrier. [source] Recombinant mussel adhesive protein as a gene delivery materialBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009Dong Soo Hwang Abstract Efficient target gene delivery into eukaryotic cells is important for biotechnological research and gene therapy. Gene delivery based on proteins, including histones, has recently emerged as a powerful non-viral DNA transfer technique. Here, we investigated the potential use of a recombinant mussel adhesive protein, hybrid fp-151, as a gene delivery material, in view of its similar basic amino acid composition to histone proteins, and cost-effective and high-level production in Escherichia coli. After confirming DNA binding affinity, we transfected mammalian cells (human 293T and mouse NIH/3T3) with foreign genes using hybrid fp-151 as the gene delivery carrier. Hybrid fp-151 displayed comparable transfection efficiency in both mammalian cell lines, compared to the widely used transfection agent, LipofectamineÔ 2000. Our results indicate that this mussel adhesive protein may be used as a potential protein-based gene-transfer mediator. Biotechnol. Bioeng. 2009;102: 616,623. © 2008 Wiley Periodicals, Inc. [source] Application of the biodegradable diblock copolymer poly(L -lactide)- block -poly(L -cysteine): Drug delivery and protein conjugationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 3 2010Jing Sun Abstract A novel approach to self-assembled and shell-crosslinked (SCL) micelles from the diblock copolymer poly(L -lactide)- block -poly(L -cysteine) to be used as drug and protein delivery carriers is described. Rifampicin was used as a model drug. The drug-loaded SCL micelles were obtained by self-assembly of the copolymer in the presence of the drug in aqueous media. Their morphology and size were studied with dynamic light scattering and field emission scanning electron microscopy. The rifampicin loading capacity and encapsulation efficiency were studied with ultraviolet,visible spectrophotometry. The drug-release rate in vitro depended on the oxidizing and reducing environment. Moreover, a straightforward approach to the conjugation of the copolymer with bovine serum albumin (BSA) was developed, and a gel electrophoresis test demonstrated that this conjugated BSA could be reversibly released from the copolymer substrate under reducing conditions. In conclusion, this L -cysteine copolymer can be used in drug delivery and in protein fixation and recovery. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Ion-exchange resins as drug delivery carriersJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 11 2009Xiaodi Guo Abstract There are many reports in the literature referring to the utilization of drug bound to ion-exchange resin (drug,resinate), especially in the drug delivery area. Ion-exchange resin complexes, which can be prepared from both acidic and basic drugs, have been widely studied and marketed. Salts of cationic and anionic exchange resins are insoluble complexes in which drug release results from exchange of bound drug ions by ions normally present in body fluids. Resins used are polymers that contain appropriately substituted acidic groups, such as carboxylic and sulfonic for cation exchangers; or basic groups, such as quaternary ammonium group for anion exchangers. Variables relating to the resin are the exchange capacity; degree of cross-linking, which determines the permeability of the resin, its swelling potential, and the access of the exchange sites to the drug ion; the effective pKa of the exchanging group, which determines the exchange affinity; and the resin particle size, which controls accessibility to the exchange ions. In this review, the properties of ion-exchange resins, selection of drugs that lend themselves to such an approach, selection of the appropriate resin, preparation of drug,resinate, evaluation of drug release, recent developments of drug,resinates, and applications are discussed. © 2009 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:3886,3902, 2009 [source] Development and in-vivo evaluation of insulin-loaded chitosan phthalate microspheres for oral deliveryJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 10 2007Udhumansha Ubaidulla Novel chitosan phthalate microspheres containing insulin were prepared by emulsion cross-linking technique. The feasibility of these microspheres as oral insulin delivery carriers was evaluated. The pH-responsive release behaviour of insulin from microspheres was analysed. The ability of chitosan phthalate-insulin microspheres to enhance intestinal absorption and improve the relative pharmacological availability of insulin was investigated by monitoring the plasma glucose and insulin level of streptozotocin-induced diabetic rats after oral administration of microspheres at insulin dose of 20 IU kg,1. In simulated gastric fluid (pH 2.0), insulin release from the microspheres was very slow. However, as the pH of the medium was changed to simulated intestinal fluid (pH 7.4), a rapid release of insulin occurred. The relative pharmacological efficacy for chitosan phthalate microspheres (18.66 ± 3.84%) was almost four-fold higher than the efficacy of the chitosan phthalate-insulin solution administration (4.08 ± 1.52%). Chitosan phthalate microspheres sustained the plasma glucose at pre-diabetic level for at least 16 h. These findings suggest that the microsphere is a promising carrier as oral insulin delivery system. [source] Biodegradable Polymeric Microcarriers with Controllable Porous Structure for Tissue EngineeringMACROMOLECULAR BIOSCIENCE, Issue 12 2009Xudong Shi Abstract Porous microspheres fabricated by biodegradable polymers show great potential as microcarriers for cell cultivation in tissue engineering. Herein biodegradable poly(DL -lactide) (PLA) was used to fabricate porous microspheres through a modified double emulsion solvent evaporation method. The influence of fabrication parameters, such as the stirring speed of the primary and secondary emulsion, the polymer concentration of the oil phase, and solvent type, as well as the post-hydrolysis treatment of the porous structure of the PLA microspheres are discussed. Good attachment and an active spread of MG-63 cells on the microspheres is observed, which indicates that the PLA microspheres with controllable porous structure are of great potential as cell delivery carriers for tissue engineering. [source] Phase Transition Behavior of Novel pH-Sensitive Polyaspartamide Derivatives Grafted with 1-(3-Aminopropyl)imidazoleMACROMOLECULAR BIOSCIENCE, Issue 9 2006Kwangwon Seo Abstract Summary: New pH-sensitive polyaspartamide derivatives were synthesized by grafting 1-(3-aminopropyl)imidazole and/or O -(2-aminoethyl)- O,-methylpoly(ethylene glycol) 5000 on polysuccinimide for application in intracellular drug delivery systems. The DS of 1-(3-aminopropyl)imidazole was adjusted by the feed molar ratio, and the structure of the prepared polymer was confirmed using FT-IR and 1H NMR spectroscopy. Their pH-sensitive properties were characterized by light transmittance measurements, and the particle size and its distribution were investigated by dynamic light scattering measurements at varying pH values. The pH-sensitive phase transition was clearly observed in polymer solutions with a high substitution of 1-(3-aminopropyl)imidazole. The prepared polymers showed a high buffering capacity between pH 5 and 7, and this increased with the DS of 1-(3-aminopropyl)imidazole. The pH dependence of the aggregation and de-aggregation behavior was examined using a fluorescence spectrometer. For MPEG/imidazole- g -polyaspartamides with a DS of 1-(3-aminopropyl)imidazole over 82%, self aggregates associated with the hydrophobic interactions of the unprotonated imidazole groups were observed at pH values above 7, and their mean size was over 200 nm, while the aggregates of polymers were dissociated at pH values below 7 by the protonation of imidazole groups. These pH-sensitive polyaspartamide derivatives are potential basic candidates for intracellular drug delivery carriers triggered by small pH changes. Mean particle size change of MPEG/imidazole- g -polyaspartamide as pH is varied. [source] Thermosensitive and Dissolution Properties in Nanocomposite Polymer HydrogelsMACROMOLECULAR RAPID COMMUNICATIONS, Issue 17 2009Chia-Jung Wu Abstract We investigate the phase transition behavior and dissolution resistant properties of thermo-sensitive nanocomposite hydrogels made from PEO-PPO-PEO triblock copolymer (Pluronic F127) and Laponite silicate nanoparticles. The rapid dissolution properties of F127 copolymer hydrogels usually limit their use as sustained release drug carriers. We overcome this limitation by synergistic combination of nanoparticle gelation characteristics with polymer thermo-sensitivity. We present a proof of concept that the temperature-dependent phase transitions can be shifted as a function of hydrogel composition and that the dissolution of the polymer hydrogels as well as the release of a model drug, albumin, can be significantly slowed down by addition of nanoparticles. The dissolution resistant properties generated will prove useful in the future formulation, processing and application of our polymer hydrogels for sustained release drug delivery carriers. [source] | |||||||||||||