scholarly journals Insulin smart drug delivery nanoparticles of aminophenylboronic acid–POSS molecule at neutral pH

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Won Jung Kim ◽  
Yong Jin Kwon ◽  
Chung-Hyun Cho ◽  
Sang-Kyu Ye ◽  
Kyu Oh Kim
Keyword(s):  
Diabetes Management ◽  
Entrapment Efficiency ◽  
Fast Response ◽  
Cd Spectroscopy ◽  
Endocrine Function ◽  
Triggered Release ◽  
Polyhedral Oligosilsesquioxane ◽  
Neutral Ph ◽  
Insulin Activity ◽  
Aminophenylboronic Acid

AbstractSelf-regulated “smart” insulin administration system that mimic pancreatic endocrine function would be highly desirable for diabetes management. Here, a glucose-responsive continuous insulin delivery system is developed, where novel polyhedral oligosilsesquioxane (POSS) modified with 3‐aminophenylboronic acid (APBA) were used to encapsulate insulin (insulin entrapment efficiency: 73.2%) to prepare a fast response, high stability, good distribution, and excellent biocompatible system. Due to the strong hydrophobicity of POSS, the POSS moiety is located at the core in aqueous solution and combines with the boronic group of APBA and the diol generated in PEG-insulin to form a nanomicelle structure, that is, nanoparticles naturally. Micelles self‐assembled from these molecules possess glucose‐responsiveness at varying glucose concentrations. The interaction of the PBA and diol containing insulin via boronate ester bond and its interchange with glucose was investigated by FT-IR, 1H NMR and XPS. Furthermore, the successful glucose-triggered release of insulin from the POSS-APBA micelles was investigated at neutral pH. A linear graph was plotted with the measured released insulin vs glucose concentrations, with a linear correlation coefficient (R2) value close to 1. Circular dichroism (CD) spectroscopy analysis was performed to measure insulin activity by comparing secondary structures of insulin, PEG-Insulin, and POSS-APBA@insulin. When confirming intracellular apoptosis signaling, cleaved caspase 3 and caspase 9 were not increased by 640 μg/ml POSS-APBA and POSS-APBA@insulin in HeLa, HDF and HUVE cells. Application in the biomedical field for controlled delivery of insulin appear to be promising.

scholarly journals Insulin Smart Drug Delivery Nanoparticles of Aminophenylboronic acid–POSS Molecule at Neutral pH

2021 ◽  
Author(s):  
Won Jung Kim ◽  
Yong Jin Kwon ◽  
Sang Kyu Ye ◽  
Kyu Oh Kim
Keyword(s):  
Diabetes Management ◽  
Entrapment Efficiency ◽  
Fast Response ◽  
Endocrine Function ◽  
Triggered Release ◽  
Polyhedral Oligosilsesquioxane ◽  
Neutral Ph ◽  
Pancreatic Endocrine Function ◽  
Aminophenylboronic Acid ◽  
Hdf Cells

Abstract Self-regulated “smart” insulin administration system that mimic pancreatic endocrine function would be highly desirable for diabetes management. Here, a glucose-responsive continuous insulin delivery system is developed, where novel polyhedral oligosilsesquioxane (POSS) modified with 3-aminophenylboronic acid (APBA) were used to encapsulate insulin (insulin entrapment efficiency : 73.2%; loading capacity : 50.5%) to prepare a fast response, high stability, good distribution, and excellent biocompatible system. Micelles self‐assembled from these molecules possess glucose‐responsiveness at varying glucose concentrations. The interaction of the PBA and diol containing insulin via boronate ester bond and its interchange with glucose was investigated by FT-IR, 1H NMR and XPS. Furthermore, the successful glucose-triggered release of insulin from the POSS-APBA micelles was investigated at neutral pH. A linear graph was plotted with the measured released insulin vs glucose concentrations, with a linear correlation coefficient (R2) value close to 1. When confirming intracellular apoptosis signaling, cleaved caspase 3 and caspase 9 were not increased by 640 µg/ml POSS-APBA and POSS-APBA@Insulin in HeLa cells and HDF cells. Application in the biomedical field for controlled delivery of insulin appear to be promising.

scholarly journals The promise of stem cell-derived islet replacement therapy

Diabetologia ◽  
2021 ◽  
Author(s):  
Douglas Melton
Keyword(s):  
Endocrine Cells ◽  
Diabetes Management ◽  
Insulin Pump ◽  
Glucose Monitoring ◽  
Endocrine Function ◽  
Blood Glucose Monitoring ◽  
Directed Differentiation ◽  
Insulin Independence ◽  
Insulin Dependent

AbstractPresent-day treatments for people that are insulin dependent require multiple insulin injections, sometimes with an insulin pump, coupled with regular blood glucose monitoring. The availability of modified insulins, each with peaks of activity at varying times, has improved diabetes management. On the other hand, there have been impressive results leading to insulin independence by transplantation of cadaveric islets coupled with immune suppression. This review focuses on the possibility of treating diabetes with cellular transplants, specifically with the use of pluripotent stem cells, to produce a virtually unlimited and uniform supply of human islet-like clusters by directed differentiation. Prospects for improving the in vitro differentiation of human endocrine cells for the study of endocrine function and their possible clinical uses are also discussed. Graphical abstract

Binding and potential-triggered release of l-glutamate with molecularly imprinted polypyrrole in neutral pH solutions

2014 ◽  
Vol 203 ◽  
pp. 327-332 ◽  
Author(s):  
Ivan Chernov ◽  
Helena Greb ◽  
Ulrike Janssen-Bienhold ◽  
Jürgen Parisi ◽  
Reto Weiler ◽  
...  
Keyword(s):  
Triggered Release ◽  
Molecularly Imprinted ◽  
Neutral Ph

scholarly journals Tailor-Made Pentablock Copolymer Based Formulation for Sustained Ocular Delivery of Protein Therapeutics

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Sulabh P. Patel ◽  
Ravi Vaishya ◽  
Gyan Prakash Mishra ◽  
Viral Tamboli ◽  
Dhananjay Pal ◽  
...  
Keyword(s):  
Drug Loading ◽  
Entrapment Efficiency ◽  
Polyglycolic Acid ◽  
Cd Spectroscopy ◽  
Protein Therapeutics ◽  
Release Profile ◽  
Hydrodynamic Diameter ◽  
Burst Release ◽  
Thermosensitive Gel

The objective of this research article is to report the synthesis and evaluation of novel pentablock copolymers for controlled delivery of macromolecules in the treatment of posterior segment diseases. Novel biodegradable PB copolymers were synthesized by sequential ring-opening polymerization. Various ratios and molecular weights of each block (polyglycolic acid, polyethylene glycol, polylactic acid, and polycaprolactone) were selected for synthesis and to optimize release profile of FITC-BSA, IgG, and bevacizumab from nanoparticles (NPs) and thermosensitive gel. NPs were characterized for particle size, polydispersity, entrapment efficiency, and drug loading. In vitro release study of proteins from NPs alone and composite formulation (NPs suspended in thermosensitive gel) was performed. Composite formulations demonstrated no or negligible burst release with continuous near zero-order release in contrast to NPs alone. Hydrodynamic diameter of protein therapeutics and hydrophobicity of PB copolymer exhibited significant effect on entrapment efficiency and in vitro release profile. CD spectroscopy confirmed retention of structural conformation of released protein. Biological activity of released bevacizumab was confirmed by in vitro cell proliferation and cell migration assays. It can be concluded that novel PB polymers can serve a platform for sustained delivery of therapeutic proteins.

scholarly journals Author Correction: Insulin smart drug delivery nanoparticles of aminophenylboronic acid–POSS molecule at neutral pH

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Won Jung Kim ◽  
Yong-Jin Kwon ◽  
Chung-Hyun Cho ◽  
Sang-Kyu Ye ◽  
Kyu Oh Kim
Keyword(s):  
Drug Delivery ◽  
Neutral Ph ◽  
Aminophenylboronic Acid ◽  
Smart Drug ◽  
Smart Drug Delivery

scholarly journals Optimization of Hemoglobin Encapsulation within PLGA Nanoparticles and Their Investigation as Potential Oxygen Carriers

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1958
Author(s):  
Clara Coll-Satue ◽  
Michelle Maria Theresia Jansman ◽  
Peter Waaben Thulstrup ◽  
Leticia Hosta-Rigau
Keyword(s):  
Double Emulsion ◽  
Entrapment Efficiency ◽  
Cd Spectroscopy ◽  
Plga Nanoparticles ◽  
Loading Capacity ◽  
Oxygen Carriers ◽  
Solvent Evaporation Method ◽  
Donor Blood ◽  
Composition And Structure ◽  
Potential Oxygen

Hemoglobin (Hb)-based oxygen carriers (HBOCs) display the excellent oxygen-carrying properties of red blood cells, while overcoming some of the limitations of donor blood. Various encapsulation platforms have been explored to prepare HBOCs which aim to avoid or minimize the adverse effects caused by the administration of free Hb. Herein, we entrapped Hb within a poly(lactide-co-glycolide) (PLGA) core, prepared by the double emulsion solvent evaporation method. We study the effect of the concentrations of Hb, PLGA, and emulsifier on the size, polydispersity (PDI), loading capacity (LC), and entrapment efficiency (EE) of the resulting Hb-loaded PLGA nanoparticles (HbNPs). Next, the ability of the HbNPs to reversibly bind and release oxygen was thoroughly evaluated. When needed, trehalose, a well-known protein stabilizer that has never been explored for the fabrication of HBOCs, was incorporated to preserve Hb’s functionality. The optimized formulation had a size of 344 nm, a PDI of 0.172, a LC of 26.9%, and an EE of 40.7%. The HbNPs were imaged by microscopy and were further characterized by FTIR and CD spectroscopy to assess their chemical composition and structure. Finally, the ability of the encapsulated Hb to bind and release oxygen over several rounds was demonstrated, showing the preservation of its functionality.

Examination of Rabbit Fc Crystals

1968 ◽  
Vol 26 ◽  
pp. 140-141
Author(s):  
J. P. Robinson ◽  
P. G. Lenhert
Keyword(s):  
Molecular Weight ◽  
Flat Plate ◽  
Phosphate Buffer ◽  
Asymmetric Unit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Neutral Ph ◽  
Small Crystals ◽  
Carbon Coated ◽  
Diffraction Patterns

Crystallographic studies of rabbit Fc using X-ray diffraction patterns were recently reported. The unit cell constants were reported to be a = 69. 2 A°, b = 73. 1 A°, c = 60. 6 A°, B = 104° 30', space group P21, monoclinic, volume of asymmetric unit V = 148, 000 A°3. The molecular weight of the fragment was determined to be 55, 000 ± 2000 which is in agreement with earlier determinations by other methods.Fc crystals were formed in water or dilute phosphate buffer at neutral pH. The resulting crystal was a flat plate as previously described. Preparations of small crystals were negatively stained by mixing the suspension with equal volumes of 2% silicotungstate at neutral pH. A drop of the mixture was placed on a carbon coated grid and allowed to stand for a few minutes. The excess liquid was removed and the grid was immediately put in the microscope.

Nanostructure of semiconductor quantum dots in a borosilicate glass matrix by complementary use of HREM and AEM

1990 ◽  
Vol 48 (4) ◽  
pp. 728-729
Author(s):  
M.J. Kim ◽  
L.C. Liu ◽  
S.H. Risbud ◽  
R.W. Carpenter
Keyword(s):  
Quantum Dots ◽  
Borosilicate Glass ◽  
Glass Matrix ◽  
Optical Switching ◽  
Response Times ◽  
Fast Response ◽  
Processing Technique ◽  
Internal Stresses ◽  
Electron Hole ◽  
Spatial Dimensions

When the size of a semiconductor is reduced by an appropriate materials processing technique to a dimension less than about twice the radius of an exciton in the bulk crystal, the band like structure of the semiconductor gives way to discrete molecular orbital electronic states. Clusters of semiconductors in a size regime lower than 2R {where R is the exciton Bohr radius; e.g. 3 nm for CdS and 7.3 nm for CdTe) are called Quantum Dots (QD) because they confine optically excited electron- hole pairs (excitons) in all three spatial dimensions. Structures based on QD are of great interest because of fast response times and non-linearity in optical switching applications.In this paper we report the first HREM analysis of the size and structure of CdTe and CdS QD formed by precipitation from a modified borosilicate glass matrix. The glass melts were quenched by pouring on brass plates, and then annealed to relieve internal stresses. QD precipitate particles were formed during subsequent "striking" heat treatments above the glass crystallization temperature, which was determined by differential thermal analysis.

Compact and efficient gas diffusion electrodes based on nanoporous alumina membranes for microfuel cells and gas sensors

The Analyst ◽  
2020 ◽  
Vol 145 (1) ◽  
pp. 122-131 ◽  
Author(s):  
Wanda V. Fernandez ◽  
Rocío T. Tosello ◽  
José L. Fernández
Keyword(s):  
Response Times ◽  
Hydrogen Oxidation ◽  
Fast Response ◽  
Gas Diffusion ◽  
Limiting Current ◽  
Gas Diffusion Electrodes ◽  
Nanoporous Alumina ◽  
Alumina Membranes ◽  
Current Densities ◽  
Microfuel Cells

Gas diffusion electrodes based on nanoporous alumina membranes electrocatalyze hydrogen oxidation at high diffusion-limiting current densities with fast response times.

Compositional Tuning of Negative Differential Resistance in Bulk Silver Iodide Memristor

2020 ◽  
Author(s):  
SMITA GAJANAN NAIK ◽  
Mohammad Hussain Kasim Rabinal
Keyword(s):  
Power Consumption ◽  
Negative Differential Resistance ◽  
Silver Iodide ◽  
Differential Resistance ◽  
Fast Response ◽  
Low Power Consumption ◽  
Switching Effect ◽  
Memory Switching ◽  
Bulk Silver ◽  
Emerging Memory

Electrical memory switching effect has received a great interest to develop emerging memory technology such as memristors. The high density, fast response, multi-bit storage and low power consumption are their...

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