Calcium ion modulates protein release from chitosan-hyaluronic acid poly electrolyte gel

2015 ◽  
Vol 55 (9) ◽  
pp. 2089-2097 ◽  
Author(s):  
A. Shanti Krishna ◽  
C. Radhakumary ◽  
K. Sreenivasan
Keyword(s):  
Hyaluronic Acid ◽  
Calcium Ion ◽  
Protein Release

scholarly journals How Poloxamer Addition in Hyaluronic-Acid-Decorated Biodegradable Microparticles Affects Polymer Degradation and Protein Release Kinetics

2021 ◽  
Vol 11 (16) ◽  
pp. 7567
Author(s):  
Teresa Silvestri ◽  
Barbara Immirzi ◽  
Giovanni Dal Poggetto ◽  
Paola Di Donato ◽  
Valentina Mollo ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Degradation Rate ◽  
Degradation Kinetics ◽  
Dynamic Balance ◽  
Release Kinetics ◽  
Slight Modification ◽  
Gel Permeation Chromatography ◽  
Protein Release ◽  
Polymeric Microparticles ◽  
Biodegradable Microparticles

Polymeric microparticles (MPs) designed for the intravitreal administration of therapeutic proteins result in a prolonged half-life in the vitreous and can delay or discourage the onset of adverse effects inevitably related to this route of administration. Hence, here we designed MPs composed of a polymeric blend based on poly(lactic-co-glycolic) acid and poloxamers, externally decorated with hyaluronic acid. The MPs are intended for intravitreal administration of bovine serum albumin. In detail, a systematic formulative study aiming to shed light on the complex relationship between protein release rate and MP degradation rate was carried out by means of calorimetric and gel permeation chromatography analyses. We found out that poloxamer addition caused a compact MP matrix, which led to a slight modification of the degradation kinetics and a reduction in the initial BSA initial release, which is of the utmost importance to ensure a relatively regular BSA release. It must also be underlined that for acid-labile molecules such as proteins, the poloxamer’s presence induced complex and hardly predictable effects on MP degradation/protein release, due to the dynamic balance between the time-evolving hydrophilicity of MPs and the influence of poloxamers themselves on the PLGA degradation rate.

Modulating Protein Release Profiles by Incorporating Hyaluronic Acid into PLGA Microparticles Via a Spray Dryer Equipped with a 3-Fluid Nozzle

2014 ◽  
Vol 31 (11) ◽  
pp. 2940-2951 ◽  
Author(s):  
Feng Wan ◽  
Morten Jonas Maltesen ◽  
Sune Klint Andersen ◽  
Simon Bjerregaard ◽  
Stefania G. Baldursdottir ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Protein Release ◽  
Spray Dryer ◽  
Plga Microparticles ◽  
Release Profiles

Biodegradable Hyaluronic Acid/N-Carboxyethyl Chitosan/Protein Ternary Complexes as Implantable Carriers for Controlled Protein Release

2005 ◽  
Vol 5 (12) ◽  
pp. 1226-1233 ◽  
Author(s):  
Hongliang Jiang ◽  
Yijuan Wang ◽  
Qian Huang ◽  
Yan Li ◽  
Chaonan Xu ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Ternary Complexes ◽  
Protein Release

Injectable Hydrogel for Sustained Protein Release by Salt-Induced Association of Hyaluronic Acid Nanogel

2012 ◽  
Vol 12 (4) ◽  
pp. 475-483 ◽  
Author(s):  
Takashi Nakai ◽  
Tai Hirakura ◽  
Yuji Sakurai ◽  
Tsuyoshi Shimoboji ◽  
Masaki Ishigai ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Protein Release ◽  
Injectable Hydrogel ◽  
Sustained Protein Release

Lead aspartate: a new en bloc stain for electron microscopy

1978 ◽  
Vol 36 (2) ◽  
pp. 34-35
Author(s):  
J.R. Walton
Keyword(s):  
Electron Microscopy ◽  
Calcium Ion ◽  
Enzyme Reaction ◽  
Lead Citrate ◽  
Reaction Products ◽  
En Bloc ◽  
Thin Sections ◽  
Lead Salts ◽  
Thin Sectioning ◽  
High Alkalinity

In electron microscopy, lead is the metal most widely used for enhancing specimen contrast. Lead citrate requires a pH of 12 to stain thin sections of epoxy-embedded material rapidly and intensively. However, this high alkalinity tends to leach out enzyme reaction products, making lead citrate unsuitable for many cytochemical studies. Substitution of the chelator aspartate for citrate allows staining to be carried out at pH 6 or 7 without apparent effect on cytochemical products. Moreover, due to the low, controlled level of free lead ions, contamination-free staining can be carried out en bloc, prior to dehydration and embedding. En bloc use of lead aspartate permits the grid-staining step to be bypassed, allowing samples to be examined immediately after thin-sectioning.Procedures. To prevent precipitation of lead salts, double- or glass-distilled H20 used in the stain and rinses should be boiled to drive off carbon dioxide and glassware should be carefully rinsed to remove any persisting traces of calcium ion.

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