Conventional Gel Systems Research Articles

Design and assessment of in silico screened diosmin incorporated ultra-flexible topical lipid gel system for the treatment of varicose vein

The ultra-flexible lipid gel system (UFLGS) consists of bilayer lipid membranes, responsible for highly elastic and deformable vesicles compared to conventional topical systems. Varicose veins are abnormal, dilated blood vessels resulting from weakening in the wall of the blood vessels. A flavonoid diosmin is highly potential to alleviate circulatory issues by altering blood veins’ elasticity and suppleness. Schrodinger 2023-1 suite device was used for molecular docking study. Ultra-flexible lipid nanosuspension (UFLNS) was developed and optimized. Then, they are characterized for Fourier transform infrared spectroscopy, differential scanning calorimetry, entrapment efficiency, transmission electron microscopy, atomic force microscopy, and turbidity measurement studies. After incorporating into the aqueous gelling agent Carbopol 934, Diosmin UFLGS (DUFLGS) was compared with the diosmin conventional gel system (DCGS) for its physicochemical properties. The docking score was –8.507, representing good interaction and binding affinity for nuclear factor-kappaB-inducing kinase. The particle size, polydispersity index, and surface charge of optimized diosmin-loaded UFLNS (DUFLNS) were found to be ideal values 144.56 ± 5.1 nm, 0.397 ± 0.13, and –24 ± 0.9 mV, respectively. The results of DUFLNS, DUFLGS, and DCGS showed skin retention values of 55.5% ± 13%, 83.44% ± 12%, and 66.39% ± 14%, respectively. The sustained release of the DUFLGS is owing to the elasticity of the ultra-flexible lipids, thereby the penetration enhanced compared to DCGS.

Preparation and enhancement mechanisms of a novel modified nanographite hybrid polymer gel for profile control in deep reservoirs

This study presents the development of modified nanographite (MG) as a crosslinking agent to enhance the temperature and salt resistance of gel systems and enable their use in deep oil and gas reservoirs. The novel nanographite hybrid crosslinked gel was formed by combining polyacrylamide (PAM) as the polymer matrix with hexamethylenetetramine (HMTA), hydroquinone (HQ), and MG as the crosslinking agents. The effects of the MG concentration on the gelation time, gel strength, and thermal stability were investigated, and the plugging ability of the nanographite hybrid crosslinked gel system was evaluated. The results demonstrated that the gelation time of the hybrid gel system comprising 0.8 wt% PAM, 0.6 wt% HMTA, 0.6 wt% HQ, and 0.2 wt% MG was 4 h, and the maximum tolerance temperature was 154.9 °C. Furthermore, the addition of MG more than doubled the storage modulus (G') and loss modulus (G′') of the gel system. Compared to the conventional gel system without MG, the hybrid gel exhibited remarkable bound water contents as high as 21.14%, which represented a more than 5-fold improvement. Microstructural analyses revealed that the hybrid gel network contained numerous MG sheets, leading to a denser network structure compared to that of the conventional gel. The presence of the MG greatly increased the network strength and crosslinking density of the hybrid gel, thereby improving its thermal stability, temperature resistance, and salt resistance. Additionally, the hybrid gel exhibited excellent plugging performance, achieving a core plugging rate of 96.2%.

Study on a new composite gel system

A composite gel system was developed to solve the problems of low gel forming viscosity, gel forming and high salinity resistance in pH range of 6~8. The viscosity of the gel was determined by rotary viscometer, and the performance of the composite gel was analyzed. The pH of the composite gel, the gelation property of the mineralized degree and the plugging test of the sand filling pipe and the oil displacement experiment were carried out. The results showed that the gel performance of the composite gel was better than that of the conventional gel system at 60 degrees Celsius. The viscosity of the composite gel reached 10000 mPa S, at 0.1% polyacrylamide concentration, the gel forming range of pH was 6~12, and the viscosity of 20000 mg/L NaCl solution reached 15000 mPa/s, which had better salt resistance. The plugging test of sand filling pipe showed that the plugging rate of the gel to permeation layer was close to 90%, and the plugging ability was better. After 18% 0.2pv injection, the recovery rate increased by about 18%, which can meet the requirements of profile control in most oilfields.

Synthesis, characterization and evaluation of polyacrylamide graft starch/clay nanocomposite hydrogel system for enhanced oil recovery

In this paper the suitability of a graft polymer nanocomposite hydrogel system for enhanced oil recovery was examined using polyacrylamide graft starch/clay nanocomposite (a laboratory synthesized product) and chromium (III) acetate (crosslinker). X-ray diffraction analysis, Fourier transform infrared spectrometry analysis, field-emission scanning electron microscopy and transmission electron microscopy were carried out to reveal the laboratory synthesized product as a nanocomposite. The effects of various parameters like salt concentration, pH, temperature, polymer concentration and crosslinker concentration on the properties of the developed gel system were systematically evaluated. The thermal stability of the nanocomposite gel and the conventional gel system were also determined by thermogravimetric analysis. The graft polymer nanocomposite gel system exhibited acceptable gel strength, gelation time and gel stability compared with the conventional gel system. The nanocomposite gels prepared using a low crosslinker concentration showed higher gel strength and required longer gelation time than the conventional gel which is more desirable properties for the effective placement of gel during enhanced oil recovery operations. In addition, sand pack flooding experiments show that the graft polymer nanocomposite gels had better plugging capacity than the conventional gel systems under reservoir conditions. Hence, this gel system may be suitable in the water shutoff treatments required for enhanced oil recovery from oilfields.

Novel Fish Oil-based Bigel System for Controlled Drug Delivery and its Influence on Immunomodulatory Activity of Imiquimod Against Skin Cancer.

To characterize bigel system as a topical drug delivery vehicle and to establish the immunomodulatory role of imiquimod-fish oil combination against skin cancer and inflammation resulting from chemical carcinogenesis. Imiquimod-loaded fish oil bigel colloidal system was prepared using a blend of carbopol hydrogel and fish oil oleogel. Bigels were first characterized for their mechanical properties and compared to conventional gel systems. Ex vivo permeation studies were performed on murine skin to analyze the ability of the bigels to transport drug across skin and to predict the release mechanism via mathematical modelling. Furthermore, to analyze pharmacological effectiveness in skin cancer and controlling imiquimod-induced inflammatory side effects, imiquimod-fish oil combination was tested in vitro on epidermoid carcinoma cells and in vivo in Swiss albino mice cancer model. Imiquimod-loaded fish oil bigels exhibited higher drug availability inside the skin as compared to individual imiquimod hydrogel and oleogel controls through quasi-Fickian diffusion mechanism. Imiquimod-fish oil combination in bigel enhanced the antitumor effects and significantly reduced serum pro-inflammatory cytokine levels such as tumor necrosis factor-alpha and interleukin-6, and reducing tumor progression via inhibition of vascular endothelial growth factor. Imiquimod-fish oil combination also resulted in increased expression of interleukin-10, an anti-inflammatory cytokine, which could also aid anti-tumor activity against skin cancer. Imiquimod administration through abigel vehicle along with fish oil could be beneficial for controlling imiquimod-induced inflammatory side effects and in the treatment of skin cancer.

Self‐Assembled Nanofibrillar Aggregates with Amphiphilic and Lipophilic Molecules

AbstractSummary: This article gives a review on self‐assembled nanofibrillar aggregates such as helical, twisted ribbon‐like and tubular forms, those are produced in aqueous bilayer membrane and organogel systems. Two common features necessary for the chemical structure that yields special morphology are a chiral carbon atom and moieties feasible for intermolecular interactions although there are some exceptions. In aqueous systems, a hydrophobic effect is also an essential driving force for molecular aggregates in aqueous solution systems but almost disappear in organic media. More positive intermolecular interactions play an important role in molecular aggregation in organic media. Hydrogen bonding interaction is especially effective and many organogelators are classified into this category. Some lipophilic peptides have been investigated not only as organogelators but also with respect to their self‐assembling behaviors. This latter property gives them distinct advantages compared with conventional gel systems because the gels include highly‐ordered structures supramolecular functions like aqueous lipid membranes through molecular orientation. This article also introduces applicability of the organogel system.

A discontinuous buffer system increasing resolution and reproducibility in DNA sequencing on high voltage horizontal ultrathin-layer electrophoresis.

A novel discontinuous buffer system for DNA sequencing based on horizontal ultrathin-layer gel electrophoresis is described. The optimized system, named unbuffered stacking gel/discontinuous borate EDTA-buffer system, is composed of a 0.5 mm thick stacking gel, where standard sequencing reactions (1 microL volume) are easily loaded, and a 50 microns ultrathin running gel, where DNA fragments are separated. The novel discontinuous buffer system allows for sample concentration and efficient injection from the stacking gel into the capillary slab gel. Increased resolution, assessed by autoradiography, can be achieved within 25 min running time already over a 10.1 cm distance from the gel slot compared to the conventional gel system. An advantage of the new system is the capacity to resolve compressions in GC-rich regions, usually causing migrating artifacts in standard gels. The described system affords a major improvement in speed, resolution and reproducibility in DNA sequencing.

Genetic heterogeneity within individual bovine rotavirus isolates.

The genomic RNA patterns of six different bovine rotavirus isolates were analyzed on high-percentage polyacrylamide gels (12.5, 13.6, and 17.5%). In contrast to the RNA patterns exhibited by conventional gel systems, those on the high-percentage gels showed an improvement in segment resolution which consequently aided in the detection of extensive band splitting in these patterns. The ability to clone out various electrophoretically distinct virus subpopulations from each of the six isolates provided an explanation for the band splitting detected by the high-resolution gels. The significance of the coexistence of genetically distinct rotavirus populations within a single host is discussed.