Encapsulation of oxime acetylcholinesterase reactivators: influence of physiological conditions on the stability of oxime-cucurbit[7]uril complexes

2020 ◽  
Vol 44 (34) ◽  
pp. 14367-14372
Author(s):  
Rudolf Andrýs ◽  
Aneta Klusoňová ◽  
Miroslav Lísa ◽  
Jana Žd'árová Karasová
Keyword(s):  
Physiological Conditions ◽  
Organophosphate Intoxication ◽  
The Stability ◽  
Acetylcholinesterase Reactivators ◽  
Guest Chemistry

The influence of physiological conditions on the host–guest chemistry of oxime acetylcholinesterase reactivators with cucurbit[7]urile was investigated to increase their effectiveness for the treatment of organophosphate intoxication.

scholarly journals Stability Evaluation and Degradation Studies of DAC® Hyaluronic-Polylactide Based Hydrogel by DOSY NMR Spectroscopy

Biomolecules ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1478
Author(s):  
Tatiana Guzzo ◽  
Fabio Barile ◽  
Cecilia Marras ◽  
Davide Bellini ◽  
Walter Mandaliti ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Nmr Spectroscopy ◽  
Bone Growth ◽  
Orthopedic Implants ◽  
Structured Surfaces ◽  
Physiological Conditions ◽  
Hydrophilic Character ◽  
Dosy Nmr ◽  
The Stability

The stability and the degradation of polymers in physiological conditions are very important issues in biomedical applications. The copolymer of hyaluronic acid and poly-D,L-lactic acid (made available in a product called DAC®) produces a hydrogel which retains the hydrophobic character of the poly-D,L-lactide sidechains and the hydrophilic character of a hyaluronic acid backbone. This hydrogel is a suitable device for the coating of orthopedic implants with structured surfaces. In fact, this gel creates a temporary barrier to bacterial adhesion by inhibiting colonization, thus preventing the formation of the biofilm and the onset of an infection. Reabsorbed in about 72 h after the implant, this hydrogel does not hinder bone growth processes. In the need to assess stability and degradation of both the hyaluronan backbone and of the polylactic chains along time and temperature, we identified NMR spectroscopy as a privileged technique for the characterization of the released species, and we applied diffusion-ordered NMR spectroscopy (DOSY-NMR) for the investigation of molecular weight dispersion. Our diffusion studies of DAC® in physiological conditions provided a full understanding of the product degradation by overcoming the limitations observed in applying classical chromatography approaches by gel permeation UV.

scholarly journals Chitosan–Azide Nanoparticle Coating as a Degradation Barrier in Multilayered Polyelectrolyte Drug Delivery Systems

Biomolecules ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 573 ◽  
Author(s):  
Steffen Sydow ◽  
Armin Aniol ◽  
Christoph Hadler ◽  
Henning Menzel
Keyword(s):  
Drug Delivery Systems ◽  
Uv Light ◽  
Film Structure ◽  
Layer By Layer ◽  
Multilayer Systems ◽  
Ionotropic Gelation ◽  
Physiological Conditions ◽  
Degree Of Acetylation ◽  
Implant Coating ◽  
The Stability

Therapeutics, proteins or drugs, can be encapsulated into multilayer systems prepared from chitosan (CS)/tripolyphosphat (TPP) nanogels and polyanions. Such multilayers can be built-up by Layer-by-Layer (LbL) deposition. For use as drug-releasing implant coating, these multilayers must meet high requirements in terms of stability. Therefore, photochemically crosslinkable chitosan arylazide (CS–Az) was synthesized and nanoparticles were generated by ionotropic gelation with TPP. The particles were characterized with regard to particle size and stability and were used to form the top-layer in multilayer films consisting of CS–TPP and three different polysaccharides as polyanions, namely alginate, chondroitin sulfate or hyaluronic acid, respectively. Subsequently, photo-crosslinking was performed by irradiation with UV light. The stability of these films was investigated under physiological conditions and the influence of the blocking layer on layer thickness was investigated by ellipsometry. Furthermore, the polyanion and the degree of acetylation (DA) of chitosan were identified as additional parameters that influence the film structure and stability. Multilayer systems blocked with the photo-crosslinked chitosan arylazide showed enhanced stability against degradation.

Design and Stability Improvement of Pectin-Based Red Blood Cell-Mimicking Microcapsules for Oxygen Therapeutics

2021 ◽  
Vol 17 (9) ◽  
pp. 1798-1805
Author(s):  
Damien Phakousonh ◽  
Yale Wang ◽  
Sabrina Schlicht ◽  
Sam Wiskirchen ◽  
Trevor Bos ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cross Linking ◽  
Physiological Conditions ◽  
Low Concentrations ◽  
Cross Linker ◽  
The Stability

A pectin-oligochitosan microcapsule system has recently been developed for novel oxygen therapeutic design. To improve the stability of the pectin-oligochitosan microcapsules in physiological conditions, both covalent (glutaraldehyde) and noncovalent (Mn2+ and Ca2+) cross-linkers were tested. The chemistry and morphology of the microcapsules were studied using FTIR and SEM, respectively. Results showed that glutaraldehyde is an effective cross-linker, even at low concentrations and short incubation times, and the glutaraldehyde cross-linking does not negatively impact the morphology of the microcapsules. Moreover, it was confirmed that the hemoglobin could be retained within the microcapsules with a minimal release.

BSA-coated magnetic nanoparticles for improved therapeutic properties

2015 ◽  
Vol 3 (30) ◽  
pp. 6239-6247 ◽  
Author(s):  
Antonio Aires ◽  
Sandra M. Ocampo ◽  
David Cabrera ◽  
Leonor de la Cueva ◽  
Gorka Salas ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Nanoparticles ◽  
Cellular Uptake ◽  
Physiological Conditions ◽  
Therapeutic Properties ◽  
The Stability

Albumin coating improves the stability of magnetic nanoparticles under physiological conditions, favoring their magnetic properties, cellular uptake, and chemotherapeutic effects.

scholarly journals Investigation of factors affecting xylanase activity from Trichoderma harzianum 1073 D3

2005 ◽  
Vol 48 (2) ◽  
pp. 187-193 ◽  
Author(s):  
Seyis Isil ◽  
Aksoz Nilufer
Keyword(s):  
Trichoderma Harzianum ◽  
Xylanase Activity ◽  
Stability Studies ◽  
Original Activity ◽  
Factors Affecting ◽  
Physiological Conditions ◽  
Xylanase Enzyme ◽  
Semi Solid ◽  
The Stability ◽  
Ph Range

In this study, some physiological conditions affecting the activity of xylanase enzyme produced from Trichoderma harzianum 1073 D3 were determined. In addition, stabilization of pH and temperature in liquid and semi-solid state cultivation media were investigated. It was concluded that for maximum xylanase activity, incubation at 60°C in an enzyme incubation medium with pH 5 that contained 1 % xylan was appropriate. The stability studies showed that the enzyme was relatively stable in the pH range 3-7 and retained more than 50 % of its original activity after four months.

scholarly journals Human Serum Albumin Increases the Stability of Green Tea Catechins in Aqueous Physiological Conditions

PLoS ONE ◽  
2015 ◽  
Vol 10 (7) ◽  
pp. e0134690 ◽  
Author(s):  
Angelo Zinellu ◽  
Salvatore Sotgia ◽  
Bastianina Scanu ◽  
Mauro Forteschi ◽  
Roberta Giordo ◽  
...  
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Green Tea ◽  
Tea Catechins ◽  
Physiological Conditions ◽  
Green Tea Catechins ◽  
The Stability

scholarly journals Macro- and Micro-Heterogeneity of Natural and Recombinant IgG Antibodies

Antibodies ◽  
2019 ◽  
Vol 8 (1) ◽  
pp. 18 ◽  
Author(s):  
Alain Beck ◽  
Hongcheng Liu
Keyword(s):  
Igg Antibodies ◽  
Pharmaceutical Development ◽  
Structural Modifications ◽  
Physiological Conditions ◽  
Safety Risks ◽  
Physico Chemical ◽  
Product Profile ◽  
Recombinant Mabs ◽  
The Stability ◽  
Quality Target Product Profile

Recombinant monoclonal antibodies (mAbs) intended for therapeutic usage are required to be thoroughly characterized, which has promoted an extensive effort towards the understanding of the structures and heterogeneity of this major class of molecules. Batch consistency and comparability are highly relevant to the successful pharmaceutical development of mAbs and related products. Small structural modifications that contribute to molecule variants (or proteoforms) differing in size, charge or hydrophobicity have been identified. These modifications may impact (or not) the stability, pharmacokinetics, and efficacy of mAbs. The presence of the same type of modifications as found in endogenous immunoglobulin G (IgG) can substantially lower the safety risks of mAbs. The knowledge of modifications is also critical to the ranking of critical quality attributes (CQAs) of the drug and define the Quality Target Product Profile (QTPP). This review provides a summary of the current understanding of post-translational and physico-chemical modifications identified in recombinant mAbs and endogenous IgGs at physiological conditions.

scholarly journals Degradation of ZIF-8 in phosphate buffered saline media

CrystEngComm ◽  
2019 ◽  
Vol 21 (31) ◽  
pp. 4538-4544 ◽  
Author(s):  
Miriam de J. Velásquez-Hernández ◽  
Raffaele Ricco ◽  
Francesco Carraro ◽  
F. Ted Limpoco ◽  
Mercedes Linares-Moreau ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Zeolitic Imidazolate Framework ◽  
Physiological Conditions ◽  
The Stability ◽  
Phosphate Buffered Saline

Understanding the stability of zeolitic imidazolate framework-8 (ZIF-8) under physiological conditions is critical in biotechnology and biomedicine for biosensing, biocatalysis, and drug delivery.

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