Impact of dynamic sub-populations within grafted chains on the protein binding and colloidal stability of PEGylated nanoparticles.

Nanoscale ◽  
2021 ◽  
Author(s):  
Delyan Hristov ◽  
Hender Lopez ◽  
Yannick Ortin ◽  
Kate O'Sullivan ◽  
Kenneth A Dawson ◽  
...  

Polyethylene glycol grafting has played a central role in preparing the surfaces of nano-probes for biological interaction; to extend blood circulation times and to modulate protein recognition and cellular uptake....

MRS Advances ◽  
2020 ◽  
Vol 5 (63) ◽  
pp. 3353-3360
Author(s):  
Susana Helena Arellano Ramírez ◽  
Perla García Casillas ◽  
Christian Chapa González

AbstractA significant area of research is biomedical applications of nanoparticles which involves efforts to control the physicochemical properties through simple and scalable processes. Gold nanoparticles have received considerable attention due to their unique properties that they exhibit based on their morphology. Gold nanospheres (AuNSs) and nanorods (AuNRs) were prepared with a seed-mediated method followed of polyethylene glycol (PEG)-coating. The seeds were prepared with 0.1 M cetyltrimethyl-ammonium bromide (CTAB), 0.005 M chloroauric acid (HAuCl4), and 0.01 M sodium borohydride (NaBH4) solution. Gold nanoparticles with spherical morphology was achieved by growth by aggregation at room temperature, while to achieve the rod morphology 0.1 M silver nitrate (AgNO3) and 0.1 M ascorbic acid solution were added. The gold nanoparticles obtained by the seed-mediated synthesis have spherical or rod shapes, depending on the experimental conditions, and a uniform particle size. Surface functionalization was developed using polyethylene glycol. Morphology, and size distribution of AuNPs were evaluated by Field Emission Scanning Electron Microscopy. The average size of AuNSs, and AuNRs was 7.85nm and 7.96 x 31.47nm respectively. Fourier transform infrared spectrometry was performed to corroborate the presence of PEG in the AuNPs surface. Additionally, suspensions of AuNSs and AuNRs were evaluated by UV-Vis spectroscopy. Gold nanoparticles were stored for several days at room temperature and it was observed that the colloidal stability increased once gold nanoparticles were coated with PEG due to the shield formed in the surface of the NPs and the increase in size which were 9.65±1.90 nm of diameter for AuNSs and for AuNRs were 29.03±5.88 and 8.39±1.02 nm for length and transverse axis, respectively.


2018 ◽  
Author(s):  
Hossam H Tayeb ◽  
Marina Stienecker ◽  
Anton Middelberg ◽  
Frank Sainsbury

Biosurfactants, are surface active molecules that can be produced by renewable, industrially scalable biologic processes. DAMP4, a designer biosurfactant, enables the modification of interfaces via genetic or chemical fusion to functional moieties. However, bioconjugation of addressable amines introduces heterogeneity that limits the precision of functionalization as well as the resolution of interfacial characterization. Here we designed DAMP4 variants with cysteine point mutations to allow for site-specific bioconjugation. The DAMP4 variants were shown to retain the structural stability and interfacial activity characteristic of the parent molecule, while permitting efficient and specific conjugation of polyethylene glycol (PEG). PEGylation results in a considerable reduction on the interfacial activity of both single and double mutants. Comparison of conjugates with one or two conjugation sites shows that both the number of conjugates as well as the mass of conjugated material impacts the interfacial activity of DAMP4. As a result, the ability of DAMP4 variants with multiple PEG conjugates to impart colloidal stability on peptide-stabilized emulsions is reduced. We suggest that this is due to constraints on the structure of amphiphilic helices at the interface. Specific and efficient bioconjugation permits the exploration and investigation of the interfacial properties of designer protein biosurfactants with molecular precision. Our findings should therefore inform the design and modification of biosurfactants for their increasing use in industrial processes, and nutritional and pharmaceutical formulations.


Nanoscale ◽  
2021 ◽  
Author(s):  
Zhanlin Zhang ◽  
Dandan Zhang ◽  
Bo Qiu ◽  
Wenxiong Cao ◽  
Yuan Liu ◽  
...  

Cancer chemotherapy remains challenging to pass through various biological and pathological barriers from blood circulation, tumor infiltration and cellular uptake before intracellular release of antineoplastic agents. Herein, icebreaker-inspired Janus nanomotors...


2015 ◽  
Vol 3 (16) ◽  
pp. 3331-3339 ◽  
Author(s):  
Zi Gu ◽  
Huali Zuo ◽  
Li Li ◽  
Aihua Wu ◽  
Zhi Ping Xu

We introduced a new strategy of albumin pre-coating to effectively stabilise layered double hydroxide (LDH) nanoparticles for biomedical applications.


1965 ◽  
Vol 32 (2) ◽  
pp. 141-151 ◽  
Author(s):  
M. W. SMITH ◽  
N. A. THORN

SUMMARY Hypercalcaemia produced in rats by the intravenous injection of calcium chloride, slowed the rate of disappearance of injected vasopressin from the blood circulation. 24% of the vasopressin injected appeared in the urine of hypercalcaemic rats compared with 7 % in control animals. Vasopressin injected intravenously into control rats was distributed in a volume equal to the blood volume but when rats had been made hypercalcaemic, the theoretical volume of distribution was three to four times greater. Antidiuresis produced by injection of large doses of vasopressin into hydrated rats was little affected by changes in the blood concentration of calcium. Calcium chloride injected intravenously into hydrated rats resulted in a temporary antidiuresis. Experiments in vitro with Sephadex G-25 showed that both ox neurophysin and rat serum protein bind vasopressin and that calcium interferes with the binding. It is suggested that calcium can compete directly with vasopressin for acidic binding sites on proteins; that this can cause the release of vasopressin and alter the transport and possibly the rate of inactivation, of vasopressin.


2009 ◽  
Vol 382 (1-2) ◽  
pp. 254-261 ◽  
Author(s):  
Suk Hyun Jung ◽  
Soon Hwa Jung ◽  
Hasoo Seong ◽  
Sun Hang Cho ◽  
Kyu-Sung Jeong ◽  
...  

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2022
Author(s):  
Xiangjie Su ◽  
Mercedes Ramírez-Escudero ◽  
Feilong Sun ◽  
Joep B. van den Dikkenberg ◽  
Mies J. van Steenbergen ◽  
...  

The aim of this study was to get insight into the internalization and transport of PEGylat-ed mixed micelles loaded by vitamin K, as mediated by Scavenger Receptor B1 (SR-B1) that is abundantly expressed by intestinal epithelium cells as well as by differentiated Caco-2 cells. Inhibition of SR-B1 reduced endocytosis and transport of vitamin-K-loaded 0%, 30% and 50% PEGylated mixed micelles and decreased colocalization of the micelles with SR-B1. Confocal fluorescence microscopy, fluorescence-activated cell sorting (FACS) analysis, and surface plasmon resonance (SPR) were used to study the interaction between the mixed micelles of different compositions (varying vitamin K loading and PEG content) and SR-B1. Interaction of PEGylated micelles was independent of the vitamin K content, indicating that the PEG shell prevented vitamin K exposure at the surface of the micelles and binding with the receptor and that the PEG took over the micelles’ ability to bind to the receptor. Molecular docking calculations corroborated the dual binding of both vita-min K and PEG with the binding domain of SR-B1. In conclusion, the improved colloidal stability of PEGylated mixed micelles did not compromise their cellular uptake and transport due to the affinity of PEG for SR-B1. SR-B1 is able to interact with PEGylated nanoparticles and mediates their subsequent internalization and transport.


Nanoscale ◽  
2018 ◽  
Vol 10 (28) ◽  
pp. 13684-13693 ◽  
Author(s):  
Ramesh Marasini ◽  
Arunkumar Pitchaimani ◽  
Tuyen Duong Thanh Nguyen ◽  
Jeffrey Comer ◽  
Santosh Aryal

This comprehensive study suggested an optimum PEG polymer length of 5 kDa is advantageous for surface passivation and colloidal stability of AuNRs, which also maximizes the heat conduction from the nanorod–liquid interface to the surroundings, thereby, enhancing photothermal efficiency.


2020 ◽  
Vol 8 (22) ◽  
pp. 4870-4882 ◽  
Author(s):  
Ana Peigneux ◽  
Emanuel A. Glitscher ◽  
Rawan Charbaji ◽  
Christoph Weise ◽  
Stefanie Wedepohl ◽  
...  

Colloidal stability and cellular uptake of MamC-biomimetic magnetite nanoparticles (BMNPs) incubated with human plasma (PC-BMNPs).


1974 ◽  
Vol 8 (8) ◽  
pp. 470-475 ◽  
Author(s):  
Eric J. Lien ◽  
Jean Kuwahara ◽  
Robert T. Koda

THE PROSTATIC FLUID/PLASMA CONCENTRATION RATIO of various sulfonamides, antibiotics and antibacterial agents, and the milk/plasma ratio of sulfonamides and basic drugs have been quantitatively correlated with the degree of dissociation, as represented by log U/D, and the partition coefficient (log P). Because of the lower pH values of the prostatic fluid (6.6) and milk (6.8) as compared with the plasma pH (7.4), the degree of dissociation appears to be the most important factor in determining the distribution of these weak acids or bases. Partition coefficient also plays a secondary role. The log Po for maximum diffusion into milk is lower than that for maximum gastrointestinal, buccal or percutaneous absorption. This may be attributed to plasma protein binding which prevents diffusion of the drug from the blood circulation into the milk since high lipophilicity favors protein binding. The clinical implications of the correlations obtained are discussed.


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