scholarly journals Durable vesicles for reconstitution of membrane proteins in biotechnology

2017 ◽  
Vol 45 (1) ◽  
pp. 15-26 ◽  
Author(s):  
Paul A. Beales ◽  
Sanobar Khan ◽  
Stephen P. Muench ◽  
Lars J.C. Jeuken
Keyword(s):  
Block Copolymers ◽  
Membrane Proteins ◽  
Protein Function ◽  
Physical Stability ◽  
Great Promise ◽  
Working Environments ◽  
Improved Stability ◽  
The Stability ◽  
In Vitro Performance

The application of membrane proteins in biotechnology requires robust, durable reconstitution systems that enhance their stability and support their functionality in a range of working environments. Vesicular architectures are highly desirable to provide the compartmentalisation to utilise the functional transmembrane transport and signalling properties of membrane proteins. Proteoliposomes provide a native-like membrane environment to support membrane protein function, but can lack the required chemical and physical stability. Amphiphilic block copolymers can also self-assemble into polymersomes: tough vesicles with improved stability compared with liposomes. This review discusses the reconstitution of membrane proteins into polymersomes and the more recent development of hybrid vesicles, which blend the robust nature of block copolymers with the biofunctionality of lipids. These novel synthetic vesicles hold great promise for enabling membrane proteins within biotechnologies by supporting their enhanced in vitro performance and could also contribute to fundamental biochemical and biophysical research by improving the stability of membrane proteins that are challenging to work with.

scholarly journals The Formation of Chitosan-Coated Rhamnolipid Liposomes Containing Curcumin: Stability and In Vitro Digestion

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 560
Author(s):  
Wei Zhou ◽  
Ce Cheng ◽  
Li Ma ◽  
Liqiang Zou ◽  
Wei Liu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Functional Foods ◽  
Positive Charge ◽  
Physical Stability ◽  
In Vitro Digestion ◽  
Salt Addition ◽  
High Transformation ◽  
Liposomal Delivery ◽  
The Stability

There is growing interest in developing biomaterial-coated liposome delivery systems to improve the stability and bioavailability of curcumin, which is a hydrophobic nutraceutical claimed to have several health benefits. The curcumin-loaded rhamnolipid liposomes (Cur-RL-Lips) were fabricated from rhamnolipid and phospholipids, and then chitosan (CS) covered the surface of Cur-RL-Lips by electrostatic interaction to form CS-coated Cur-RL-Lips. The influence of CS concentration on the physical stability and digestion of the liposomes was investigated. The CS-coated Cur-RL-Lips with RL:CS = 1:1 have a relatively small size (412.9 nm) and positive charge (19.7 mV). The CS-coated Cur-RL-Lips remained stable from pH 2 to 5 at room temperature and can effectively slow the degradation of curcumin at 80 °C; however, they were highly unstable to salt addition. In addition, compared with Cur-RL-Lips, the bioavailability of curcumin in CS-coated Cur-RL-Lips was relatively high due to its high transformation in gastrointestinal tract. These results may facilitate the design of a more efficacious liposomal delivery system that enhances the stability and bioavailability of curcumin in nutraceutical-loaded functional foods and beverages.

scholarly journals In vitro biological assessment of the stability of cigarette smoke aqueous aerosol extracts

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Mark Taylor ◽  
Simone Santopietro ◽  
Andrew Baxter ◽  
Nicole East ◽  
Damien Breheny ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cigarette Smoke ◽  
Culture Media ◽  
Physical Stability ◽  
Bronchial Epithelial Cell ◽  
Biological Assessment ◽  
Gas Chromatography Mass Spectrometry ◽  
Fresh Sample ◽  
The Stability

Abstract Objectives Cigarette smoke aqueous aerosol extracts (AqE) have been used for assessing tobacco products, particularly with in vitro models such as oxidative stress and inflammation. These test articles can be generated easily, but there are no standardised methods for the generation and characterisation or stability. We investigated the effects of pro-oxidant smoke-derived chemicals by using 3R4F AqE generated under standardised conditioning and smoking regimes and assessed the stability over 31-week timeframe. Twenty batches generated from ten puffs per cigarette bubbled through 20 ml cell culture media were used fresh and thawed from frozen aliquots stored at – 80 ºC. Results Nicotine levels quantified by gas chromatography/mass spectrometry and optical density at 260 nm showed chemical and physical stability from week 0 (fresh sample) to weeks 1, 4, 8 and 31 (frozen samples). No significant change in H292 human bronchial epithelial cell viability or oxidative stress were observed between fresh AqE at week 0 and frozen AqE at 31 weeks. AqEs generated by our protocol were stable for up to 31 weeks for all tested end points, suggesting that it may not be necessary to use freshly generated AqE for each study, thus reducing batch-to-batch variability.

Nanoemulsion Containing SangYod Rice Bran Oil and Thanakha Extracts: In Vitro Antioxidant and Irritation Assessments

2017 ◽  
Vol 866 ◽  
pp. 3-7 ◽  
Author(s):  
Orrawan Poonsri ◽  
Wiyada Kwanhian ◽  
Apakorn Poltien ◽  
Piyatida Tangteerawatana ◽  
Jitbanjong Tangpong
Keyword(s):  
Particle Size ◽  
Rice Bran ◽  
Skin Diseases ◽  
Rice Bran Oil ◽  
Physical Stability ◽  
Total Phenolic ◽  
Phenolic Contents ◽  
Total Antioxidant ◽  
The Stability

Nanoemulsions are well characterized in a promising drug delivery system with applications for drug and cosmetic. Traditionally and cosmetic industries use Rice bran oil and Hesperethusa crenulata or Thanakha bark aqueous extract in sunscreen formulations, anti ageing products and in treatments for skin diseases. The aim of this study was to produce the nanoemulsion and to evaluate their physical stability, irritation potential. In vitro study, the total phenolic contents and total antioxidant capacity of SangYod Rice bran oil (SRBO) were 1130.44 ± 53.55 mg GAE/mg and 25.94±4.69 mmol TEAC/mg and Thanakha were 3.85±0.23 mg GAE/gdw and 19.87 ± 2.59 mmol TEAC/gdw, respectively. The nanoemulsion containing SRBO and Thanakha, oil in water, was produced using low-pressure homogenizer and ultrasonicator techniques and the particle size was 167.03±1.75 nm. The stability of nanoemulsion represented no significant change on pH and particle size after day 0, 5, 11, 14 and over 12 month at temperature 4, 25 and 40 °C. Moreover, it’s also showed no irritation on HET–CAM test, a basic test for embryotoxicity, systemic toxicity and immunopathology. Conclusion, these results suggested that the nanoemulsion containing SRBO and Thanakha may serve as potential vehicles for improved transdermal delivery antioxidant compound and no irritation.

scholarly journals Structural-mechanical remodelling of GDP-microtubules by kinesin

2017 ◽  
Author(s):  
Daniel R. Peet ◽  
Nigel J. Burroughs ◽  
Robert A. Cross
Keyword(s):  
Lattice Spacing ◽  
Molecular Motor ◽  
The Self ◽  
Eukaryotic Cells ◽  
Great Promise ◽  
Structure Stability ◽  
Strong State ◽  
The Stability

Kinesin-1 is a nanoscale molecular motor that walks towards the fast growing (plus) ends of microtubules (MTs), hauling molecular cargo to specific reaction sites in cells. Kinesin-driven transport is central to the self-organisation of eukaryotic cells and shows great promise as a tool for nano-engineering1,2. Recent work hints that kinesin may also play a role in modulating the stability of its MT track, both in vitro3-5 and in vivo6, but results are conflicting7-9 and mechanisms are unclear. Here we report a new dimension to the kinesin-MT interaction, whereby strong-state (ATP-bound and apo) kinesin-1 motor domains inhibit the shrinkage of GDP-MTs by up to 2 orders of magnitude and expand their lattice spacing by ~1.6%. Our data reveal an unexpected new mechanism by which the mechanochemical cycles of kinesin and tubulin interlock, allowing motile kinesins to influence the structure, stability and mechanics of their MT track.

scholarly journals DIACEREIN-LOADED NIOSOMES (DC-NS): A NEW TECHNIQUE TO SUSTAIN THE RELEASE OF DRUG ACTION

2022 ◽  
pp. 156-163
Author(s):  
RASHAD M. KAOUD ◽  
EMAN J. HEIKAL ◽  
TAHA M. HAMMADY
Keyword(s):  
Physical Stability ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Stability Study ◽  
Molar Ratios ◽  
Tween 40 ◽  
A New Technique ◽  
The Stability ◽  
Tween 60

Objective: The study's main goal is to develop a suitable niosomes (NS) encapsulated drug for anti-inflammatory effects such as diacerein (DC) and to evaluate the system's vesicle size (VS), entrapment efficiency (EE %), physical stability and in vitro release. Methods: Tween (40 and 60), cholesterol, and stearylamine were used in a 1:1:0.1 molar ratios as non-ionic surfactants. Thin film hydration was used to create the NS. Results: The higher EE% was observed with NS (F11) prepared from tween 60, cholesterol and 2.5 min sonication. These formulations' release patterns were Higuchi diffusion and first order. For the stability study, NS formulations were stored at temperature between 2-8 °C for 60 d retains the most drugs when compared to room and high temperature conditions. Conclusion: The findings of this study have conclusively shown that after NS encapsulation of DC, drug release is prolonged at a constant and controlled rate.

pH-responsive microspheres encapsulated with iron oxide nanoaggregates for gastrointestinal delivery

2012 ◽  
Vol 27 (1) ◽  
pp. 54-66 ◽  
Author(s):  
Young Ju Son ◽  
Hyuk Sang Yoo
Keyword(s):  
Iron Oxide ◽  
Block Copolymer ◽  
Block Copolymers ◽  
Diblock Copolymer ◽  
Ph Responsive ◽  
Polymeric Microspheres ◽  
Intestinal Delivery ◽  
Poly Ethylene ◽  
The Stability

Block copolymer-stabilized iron oxide nanoaggregates were fabricated into pH-responsive polymeric microspheres for intestinal delivery of the magnetic nanoaggregates. A diblock copolymer consisted of methoxy poly(ethylene glycol) (mPEG) and poly(e-caprolactone) (PCL) was synthesized by ring-opening polymerization. Microspheres, consisted of Eudragit L100-55 encapsulate and stabilized magnetic nanoaggregates, were prepared by an oil-in-oil emulsification technique. The magnetization of the microspheres decreased, and the stability of the magnetic nanoaggregates in aqueous solutions increased as the amount of block copolymers in the microspheres increased. The encapsulated magnetic nanoaggregates were visualized by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The encapsulation efficiency of nanoaggregates of the microspheres increased as the amount of diblock copolymer in the nanoaggregates was increased. The in vitro experiments confirmed the pH-dependent release of the nanoaggregates from the microspheres. The microspheres were administered to the animals by oral gavages, and the nanoaggregates in small intestines were visualized by histological examination of intestinal inner walls. Higher amounts of the block copolymer in the nanoaggregates increased the uptake efficiency in the intestinal tissues. Thus, the incorporation of the block copolymers in the magnetic nanoaggregates increased the intestinal absorption of the aggregates and Eudragit microspheres and effectively protected the nanoaggregates at low pH conditions of the stomach area.

In Vitro Evaluation of Evacuated Blood Collection Tubes as a Closed-Suction Surgical Drain Reservoir

2018 ◽  
Vol 54 (1) ◽  
pp. 30-35
Author(s):  
Brian Heiser ◽  
E.B. Okrasinski ◽  
Rebecca Murray ◽  
Kelly McCord
Keyword(s):  
Blood Collection ◽  
Expiration Date ◽  
Closed Suction ◽  
Volume Curve ◽  
Negative Pressures ◽  
The Stability ◽  
Surgical Drain ◽  
In Vitro Performance ◽  
Blood Collection Tubes

ABSTRACT The initial negative pressures of evacuated blood collection tubes (EBCT) and their in vitro performance as a rigid closed-suction surgical drain (CSSD) reservoir has not been evaluated in the scientific literature despite being described in both human and veterinary texts and journals. The initial negative pressures of EBCT sized 3, 6, 10, and 15 mL were measured and the stability of the system monitored. The pressure-to-volume curve as either air or water was added and maximal filling volumes were measured. Evacuated blood collection tubes beyond the manufacture’s expiration date were evaluated for initial negative pressures and maximal filling volumes. Initial negative pressure ranged from −214 mm Hg to −528 mm Hg for EBCT within the manufacturer’s expiration date. Different pressure-to-volume curves were found for air versus water. Optimal negative pressures of CSSD are debated in the literature. Drain purpose and type of exudates are factors that should be considered when deciding which EBCT size to implement. Evacuated blood collection tubes have a range of negative pressures and pressure-to-volume curves similar to previously evaluated CSSD rigid reservoirs. Proper drain management and using EBCT within labeled expiration date are important to ensure that expected negative pressures are generated.

scholarly journals Current Landscape in Organic Nanosized Materials Advances for Improved Management of Colorectal Cancer Patients

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2440
Author(s):  
Octav Ginghină ◽  
Ariana Hudiță ◽  
Cătălin Zaharia ◽  
Aristidis Tsatsakis ◽  
Yaroslav Mezhuev ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Great Promise ◽  
Animal Testing ◽  
Nanosized Materials ◽  
Crc Management ◽  
Therapeutic Tools ◽  
The Stability ◽  
The Moment ◽  
Colorectal Cancer Patients

Globally, colorectal cancer (CRC) ranks as one of the most prevalent types of cancers at the moment, being the second cause of cancer-related deaths. The CRC chemotherapy backbone is represented by 5-fluorouracil, oxaliplatin, irinotecan, and their combinations, but their administration presents several serious disadvantages, such as poor bioavailability, lack of tumor specificity, and susceptibility to multidrug resistance. To address these limitations, nanomedicine has arisen as a powerful tool to improve current chemotherapy since nanosized carriers hold great promise in improving the stability and solubility of the drug payload and enhancing the active concentration of the drug that reaches the tumor tissue, increasing, therefore, the safety and efficacy of the treatment. In this context, the present review offers an overview of the most recent advances in the development of nanosized drug-delivery systems as smart therapeutic tools in CRC management and highlights the emerging need for improving the existing in vitro cancer models to reduce animal testing and increase the success of nanomedicine in clinical trials.

scholarly journals FORMULATION AND OPTIMIZATION OF NIFEDIPINE LOADED NANOCARRIERS

2021 ◽  
pp. 311-317
Author(s):  
ASHWINI JADHAV ◽  
BINOY VARGHESE CHERIYAN
Keyword(s):  
Particle Size ◽  
Zeta Potential ◽  
Physical Stability ◽  
Entrapment Efficiency ◽  
Tween 80 ◽  
Physicochemical Characteristics ◽  
Good Choice ◽  
The Stability

Objective: The main aim of this study to formulate a nifedipine-loaded nanocarrier for improving solubility and bioavailability. Methods: To improve the solubility of drug, nifedipine-loaded nanocarrier (lipotomes) were prepared by using the film lipid hydration technique. lipotomes were prepared by using tween 80, which is used for increasing solubility and cetyl alcohol for lipophilic environment. Drug excipients interaction determined by FTIR. lipotomes were characterized for particle size, Entrapment efficiency and zeta potential. lipotomes were optimized by using Design-Expert 12 software. Optimized formula further lyophilized by using different cyroproyectant to improve the stability and oral administration of the drug. Results: FTIR shows there was no interaction between formulation ingredients. Mean particle size, entrapment efficiency, zeta potential was determined and found to be 308.1 nm, 96.7%, 20.1mV, respectively. Surface morphology of lipotomes was observed by a scanning electron microscope (SEM). Optimized lipotomes was lyophilized with Mannitol (8% w/v) was the ideal cryoprotectant to retain the physicochemical characteristics of the OLT formulation after lyophilization. Conclusion: Nifedipine loaded nanocarrier was successfully prepared, using film hydration method. Which have good particle size, EE% and zeta potential. After lyophilization no significant changes was observed in particle size with good physical stability, so it could be a good choice for conventional drug delivery system by doing further investigation as in vitro and in vivo study

scholarly journals Direct reconstitution and study of SUN protein interactions in vitro using mammalian cell-free expression

2021 ◽  
Author(s):  
Sagardip Majumder ◽  
Yen-Yu Hsu ◽  
Allen P Liu
Keyword(s):  
Membrane Proteins ◽  
Mammalian Cell ◽  
Protein Function ◽  
Mammalian Cells ◽  
Expression System ◽  
Full Length ◽  
Free Expression ◽  
Lipid Bilayer Membranes ◽  
Linc Complex

SUN proteins are an integral part of LINC (Linker of Nucleoskeleton and Cytoskeleton) complex which spans the nuclear envelope and acts as a physical tether between the cytoskeletal filaments and the nuclear lamina. Several human diseases associated with nuclear deformation are primarily caused by impaired functioning of SUN proteins. Studies in yeast and mammalian cells have illustrated the detrimental effects of different SUN mutants in nuclear positioning and movement. While cell-based studies provide physiological relevance to the functioning of a protein, in vitro reconstitution of isolated proteins is useful in mechanistically dissecting protein function in a biochemically defined environment. In this study, we used a mammalian cell-free expression system to synthesize and reconstitute SUN proteins in artificial lipid bilayer membranes. Building on our previous work demonstrating directional reconstitution of full-length SUN proteins, we deciphered the mechanism of such protein reconstitution and leveraged it to test several theories/models of LINC complex assembly. By using a simple fluorescence-based assay, we revealed the importance of cations such as calcium and the presence of disulfide bonds in the formation of LINC complexes. Through sequential reconstitutions of SUN proteins and soluble luminal domains of SUN proteins, we found that coiled coil domains of SUN proteins are necessary for homomeric and heteromeric interactions of reconstituted SUN proteins. Overall, our results provide mechanistic insights on LINC complex formation and how this might impact cellular mechanotransduction. The facile approach for reconstituting full-length membrane proteins can be extended to study other difficult-to-study membrane proteins in vitro.

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