Design of Water-Soluble Quantum Dots with Novel Surface Ligands for Biological Applications

2003 ◽  
Vol 789 ◽  
Author(s):  
H. Tetsuo Uyeda ◽  
Igor L. Medintz ◽  
Hedi Mattoussi
Keyword(s):  
Aqueous Media ◽  
Extended Period ◽  
Water Soluble ◽  
Coupling Agents ◽  
Biological Applications ◽  
Dihydrolipoic Acid ◽  
Aqueous Dispersions ◽  
Surface Capping ◽  
Capping Ligands ◽  
New Generation

ABSTRACTWe have designed a series of organic oligo- and polyethylene glycol (PEG) based surface capping ligands that allow for QD manipulation in aqueous media. We utilized readily available thioctic acid and various oligo- and polyethylene glycols in simple esterification schemes, followed by reduction of the dithiolane to produce multi-gram quantities of capping substrates. Cap exchange of the native trioctyl-phosphine and -phosphine oxide based ligands with the PEG-terminated dithiol-alkyl cap readily resulted in aqueous dispersions of QDs that were homogeneous and stable in various pH ranges over an extended period of time. Mixed surface capping strategies utilizing ratios of dihydrolipoic acid to the pegylated dihydrolipoic acid were also prepared. We anticipate that such systems should allow one to covalently attach amine containing biomolecules to nanoparticle systems bearing carboxylates, employing known coupling agents, such as (dimethylamino) propyl-3-ethyl-carbodiimide (EDC). This design and conjugation strategy may facilitate the development of a new generation of QD-bioconjugates, which can be directly utilized in bio-related applications such as sensing and cellular imaging.

Formulation Optimization of Sustained Release Resinate Microcapsules of Tramadol Hydrochloride by Using 3/2 Factorial Design

2017 ◽  
Vol 6 (2) ◽  
pp. 57
Author(s):  
Kamble Ravindra K. ◽  
Chauhan Chetan S. ◽  
Kamble Priyadarshani R. ◽  
Naruka Pushpendra S.
Keyword(s):  
Drug Delivery ◽  
Ion Exchange ◽  
Sustained Release ◽  
Factorial Design ◽  
Linear Regression Analysis ◽  
Extended Period ◽  
Multiple Linear Regression Analysis ◽  
Water Soluble ◽  
Tramadol Hydrochloride ◽  
Release Drug

The main aim of the present work was to develop the microcapsules of tramadol hydrochloride for the oral sustained release drug delivery. Tramadol hydrochloride a BCS class I drug a centrally acting synthetic analgesic was complexed with Indion 254 ion exchange resin. The microcapsules were prepared by encapsulating the prepared resinates by o/o solvent evaporation technique. In the investigation 32 full factorial design was used to investigate the joint influence of two formulation variable amount of eudragit RS 100 and plasticized PEG 400. The results of multiple linear regression analysis indicated that for obtaining a sustained release drug delivery the optimum concentrations of both the plasticizer and coating solution to be used. The factorial models were used to prepare optimized microcapsules and optimized formulations showed sustained release profiles for the extended period of more than 12 hrs. From the present investigations concluded that resinate microcapsules of highly water soluble drug can provide controlled release of drug for extended period.Key Words: Tramadol hydrochloride, ion exchange resinate, microcapsules, sustained release

scholarly journals Self-Healing Polymer-Clay Hybrids by Facile Complexation of a Waterborne Polymer with a Clay

2021 ◽  
Author(s):  
Aranee Pleng Teepakakorn ◽  
Makoto Ogawa
Keyword(s):  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Water Soluble ◽  
Poly Vinyl Alcohol ◽  
Self Healing ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Smectite Clay

Water-induced self-healing materials were prepared by the hybridization of a water-soluble polymer, poly(vinyl alcohol), with a smectite clay by mixing in an aqueous media and subsequent casting. Without using chemical...

Dissociation of imino proton(s) of a highly water-soluble metal-free phthalocyanine and determination of its pKa value in water

2013 ◽  
Vol 17 (06n07) ◽  
pp. 447-453 ◽  
Author(s):  
Hiroaki Isago ◽  
Harumi Fujita
Keyword(s):  
Aqueous Media ◽  
Thermal Reaction ◽  
Water Soluble ◽  
Acid Dissociation ◽  
Acid Dissociation Constant ◽  
Metal Free ◽  
Imino Proton ◽  
Pka Value ◽  
Triton X

Dissociation of imino proton(s) in the cavity of the macrocycle of a highly water-soluble, metal-free phthalocyanine ( H 2( H 4 tsppc ); where H 4 tsppc denotes tetrakis{(2′,6′-dimethyl-4′-sulfonic acid)phenoxy}phthalocyaninate) in ethanolic and aqueous solutions has spectrophotometrically been investigated. The spectral changes associated with reaction with NaOH have been found to involve one-proton transfer process in aqueous media while two-protons process in ethanolic media. The acid-dissociation constant of the first imino proton in water (in the presence of Triton X-100) has been determined to be 12.5 ± 0.2 (as pKa) at 25 °C. The doubly deprotonated species in EtOH has been easily converted to its corresponding cobalt(II) derivative by thermal reaction with anhydrous CoCl 2.

One-Pot Synthesis of Water Soluble, Extremely Small-Sized Superparamagnetic Magnetite Nanoparticles

2012 ◽  
Vol 531 ◽  
pp. 219-222
Author(s):  
Li Hua Shen ◽  
Ting Shang ◽  
Jun Zhou ◽  
Dong Wang ◽  
Yu Han ◽  
...  
Keyword(s):  
Magnetite Nanoparticles ◽  
Room Temperature ◽  
Colloidal Stability ◽  
Aqueous Media ◽  
Mri Contrast Agents ◽  
Water Soluble ◽  
Potential Candidate ◽  
One Pot ◽  
Mri Contrast

Extremely small-sized superparamagnetic magnetite nanoparticles of 3Cit). The resulting Cit-coated magnetite nanoparticles exhibited long-term colloidal stability in aqueous media without any surface modification. Regarding the magnetic properties, the nanoparticles were superparamagnetic at room temperature, and might be the potential candidate for MRI contrast agents.

Solubilization of poorly water‐soluble bioactive molecules in neutral aqueous media by complexation with renatured β‐1,3‐1,6‐glucan nanoparticles

Biopolymers ◽  
2020 ◽  
Vol 111 (4) ◽  
Author(s):  
Ayumu Kodama ◽  
Akifumi Nakagawa ◽  
Yuki Nonoguchi ◽  
Haruka Sakurai ◽  
Chieko Yano ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Water Soluble ◽  
Bioactive Molecules ◽  
Poorly Water Soluble

Improved dispersibility of nano-graphene oxide by amphiphilic polymer coatings for biomedical applications

RSC Advances ◽  
2016 ◽  
Vol 6 (81) ◽  
pp. 77818-77829 ◽  
Author(s):  
Rana Imani ◽  
Wei Shao ◽  
Shahriar Hojjati Emami ◽  
Shahab Faghihi ◽  
Satya Prakash
Keyword(s):  
Graphene Oxide ◽  
Biomedical Applications ◽  
Aqueous Media ◽  
Polymer Coatings ◽  
Amphiphilic Polymer ◽  
Nano Materials ◽  
Biological Applications ◽  
The Poor ◽  
Nano Graphene

The poor dispersibility of graphene-based nano-materials in aqueous media is a crucial limitation in their biological applications.

Degradation of polycyclic aromatic hydrocarbons (PAHs) by a mixed culture and its component pure cultures, obtained from PAH-contaminated soil

1995 ◽  
Vol 41 (6) ◽  
pp. 470-476 ◽  
Author(s):  
D. Trzesicka-Mlynarz ◽  
O. P. Ward
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Mixed Culture ◽  
Aromatic Hydrocarbons ◽  
Aqueous Media ◽  
Water Soluble ◽  
Nitrogen Levels ◽  
Glucose Levels ◽  
Polycyclic Aromatic ◽  
Pure Cultures ◽  
The Media

A mixed culture, isolated from soil contaminated with polycyclic aromatic hydrocarbons (PAHs), grew on and degraded fluoranthene in aqueous media supplemented with glucose, yeast extract, and peptone. Increased complex nitrogen levels in the medium promoted bacterial growth and a greater extent of fluoranthene degradation. Amendment of the media with high glucose levels also diminished specific fluoranthene degradation. The mixed culture was capable of degrading a range of other PAHs, including benzo[a]pyrene, anthracene, phenanthrene, acenaphthene, and fluorene. The mixed culture contained four predominant isolates, all of which were Gram-negative rods, three of which were identified as Pseudomonas putida, Flavobacterium sp., and Pseudomonas aeruginosa. Better degradation of a defined PAH mixture was observed with the mixed culture than with individual isolates. A reconstituted culture, prepared by combining the four individual isolates, manifested a similar PAH biodegradation performance to the original mixed culture. When compared with the mixed culture, individual isolates exhibited a relatively good capacity to remove more water-soluble PAHs (acenaphthene, fluorene, phenanthrene, fluoranthene). In contrast, removal of less water-soluble PAHs (anthracene and pyrene) was low or negligible with isolated cultures compared with the mixed culture.Key words: polycyclic aromatic hydrocarbons, mixed culture, fluoranthene, Pseudomonas, Flavobacterium.

Sign in / Sign up

Export Citation Format

Share Document