Development of pH-responsive poly(γ-cyclodextrin) derivative nanoparticles.

In this study, we report a novel pH-responsive nanoparticle composed of poly(γ-cyclodextrin) [poly(γCD)] conjugated with functional 3-diethylaminopropyl (DEAP) groups [poly(γCD-DEAP)]. The design of the nanoparticle takes advantage of the biocompatible functional poly(γCD) as the backbone polymer and the unique pH-responsive feature of DEAP as either a hydrophobic moiety (non-ionic DEAP) at pH 7.4 or a hydrophilic moiety (ionic DEAP) at acidic pH.

Poly(L-aspartic acid) nanogels for lysosome-selective antitumor drug delivery.

Advanced materials that have controllable pH-responsive properties when submerged in the lysosome have a great potential in intracellular drug delivery. We developed novel poly(L-amino acid) nanogels that were prepared by a facile cross-linking of poly[L-aspartic acid-g-(3-diethylaminopropyl)]-b-poly(ethylene glycol)-maleimide [poly(L-Asp-g-DEAP)-b-PEG-Mal] and poly(L-aspartic acid-g-ethyl thiol)-b-PEG [poly(L-Asp-SH)-b-PEG] in an oil/water emulsion condition. Interestingly, these nanogels (~125 nm in diameter) modulated volume expansion (~375 nm in diameter) in a lysosomal pH (~pH 5.

Facile synthesis of multimeric micelles.

Bringing it all together: Synthesis of a dimeric micelle (see scheme) is shown to produce specifically linked Janus-like micelles. The reaction conditions for dimeric micelle formation were optimized and the resulting micelles characterized. Trimeric, tetrameric, and multimeric micelles were also synthesized using the same technique.

Multifunctional poly (lactide-co-glycolide) nanoparticles for luminescence/magnetic resonance imaging and photodynamic therapy.

Poly (lactide-co-glycolide) (PLGA) coupled with methoxy poly (ethylene glycol) (mPEG) or chlorin e6 (Ce6) was synthesized using the Steglich esterification method. PLGA-linked mPEG (PLGA-mPEG), PLGA-linked Ce6 (PLGA-Ce6), and Fe(3)O(4) were utilized to constitute multifunctional PLGA nanoparticles (∼160 nm) via the multi-emulsion W(1)/O/W(2) (water-in-oil-in-water) method. The photo-sensitizing properties of Ce6 molecules anchored to PLGA nanoparticles enabled in vivo luminescence imaging and photodynamic therapy for the tumor site.

Poly(L-aspartic acid) derivative soluble in a volatile organic solvent for biomedical application.

In order to develop a novel functional poly(L-amino acid) that can dissolve in volatile organic solvents, we prepared poly[L-aspartic acid-g-(3-diethylaminopropyl)]-b-poly(ethylene glycol) [poly(L-Asp-g-DEAP)-b-PEG] via the conjugation of 3-diethylaminopropyl (DEAP) to carboxylate groups of poly(L-Asp) (M(n) 4 K)-b-PEG (M(n) 2 K). This poly(L-aspartic acid) derivative evidenced a relatively high solubility in volatile organic solvents such as dichloromethane, chloroform, and acetone. We fabricated a model nanostructure (i.

Photodynamic therapy using glycol chitosan grafted fullerenes.

Glycol chitosan (GC)-grafted fullerene (GC-g-C(60)) conjugates were developed for use in photodynamic therapy of tumor cells. GC-g-C(60) was synthesized in anhydrous benzene/dimethylsulfoxide (DMSO) co-solvent via the chemical conjugation of free amine groups of GC to CC double bonds of C(60). The GC-g-C(60) with 5×10(-4) C(60) molecules per one repeating unit of GC was soluble in water.

An artificial photosensitizer drug network for mitochondria-selective photodynamic therapy.

We report a new class of photosensitizer drug networks that can home into mitochondria and provide geospatial phototoxicity for tumors. We take advantage of the cleavable chemical network between the photosensitizer drug and poly(ethylene glycol), and find a significant increase in the efficiency of the multimeric drug network in mitochondria uptake and tumor inhibition.

Electrostatic charge conversion processes in engineered tumor-identifying polypeptides for targeted chemotherapy.

One of the current challenges in cancer chemotherapy is the ultra-sensitive identification of in vivo tumors. Herein, we report a new class of tumor-identifying polypeptides that can home in on in vivo tumors via an electrostatic charge conversion process occurring in the acidic milieu of a verity of tumors, which can be distinguished from receptor-interacting conventional tumor-homing peptides. We exploit the chemical coupling between polypeptides and therapeutic objects (drugs or particles) to carry out an antitumor study in nude mice, and find a significant increase in the efficiency of polypeptide-tagged objects in tumor uptake and inhibition, which is more significant than any known tumor-homing peptide system thus far developed.

Antioxidant encapsulated porous poly(lactide-co-glycolide) microparticles for developing long acting inhalation system.

The purpose of this study was to fabricate porous poly(lactide-co-glycolide) (PLGA) microparticles for efficient pulmonary deposition and increased therapeutic duration of the antioxidant anthocyanin (ATH). These microparticles were prepared by a water-in-oil-in-water (W(1)/O/W(2)) multi-emulsion method with vaporizing ammonium bicarbonate (AB) as a porogen and starch as a viscous additive. High porosity achieved by the decomposition reaction of AB to the base of ammonia, carbon dioxide, and water vapor at 50°C enabled efficient deposition of ATH throughout the entire lung in BALB/c mice.

3-Diethylaminopropyl-bearing glycol chitosan as a protein drug carrier.

Polysaccharidic nanogels were fabricated with bovine serum albumin (BSA) and a glycol chitosan (GCS) grafted with functional 3-diethylaminopropyl (DEAP) groups. These nanogels were investigated to evaluate their cellular uptake in HeLa cells and in vivo fate in nude mice tumor model. Unlike free BSA, GCS-g-DEAP/BSA nanogels improved cellular uptake of BSA.

A self-organized 3-diethylaminopropyl-bearing glycol chitosan nanogel for tumor acidic pH targeting: in vitro evaluation.

In this study, a novel pH-responsive nanogel composed of glycol chitosan (GCS) grafted with functional 3-diethylaminopropyl (DEAP) groups (denoted as GCS-g-DEAP hereafter) was fabricated. The GCS-g-DEAP was designed to have a self-assembled arrangement consisting of hydrophilic block (GCS) and hydrophobic block (DEAP) at physiological pH. As the pH decreased to tumor extracellular pH (pH(e)), the nanogel was destabilized due to the protonation of DEAP.

A smart flower-like polymeric micelle for pH-triggered anticancer drug release.

Novel pH-responsive flower-like micelles were developed to provide the mechanism for pH-triggered drug release from drug carriers. The micelles (particle size: approximately 165 nm; critical micelle concentration (CMC): approximately 4 microg/ml), constructed from poly(N(epsilon)-(3-diethylamino)propyl isothiocyanato-L-lysine)-b-poly(ethylene glycol)-b-poly(L-lactide) [poly(DEAP-Lys)-b-PEG-b-PLLA], were designed to have a self-assembled flower-like arrangement consisting of two hydrophobic blocks [deprotonated poly(DEAP-Lys) block and PLLA block] and a petal-like hydrophilic PEG block at physiological pH. As the pH decreases to slightly acidic pH ( View Article and Find Full Text PDF