Conventional Soaking Method Research Articles

Microwave-Enabled Fast Preparation of a Metal-Organic Framework Hybrid Membrane for Filtration-Enhanced Simultaneous Separation and Detection of Aflatoxin B1.

Mycotoxin contamination in food and the environment seriously harms human health. Sensitive and timely detection of mycotoxins is crucial. Here, we report a dual-functional hybrid membrane with absorptivity and responsiveness for fluorescent-quantitative detection of mycotoxin aflatoxin B1 (AFB1). A biomineralization-inspired and microwave-accelerated fabrication method was established to prepare a hybrid membrane with a metal-organic framework (MOF) loaded in high density. The MOF presented high efficiency in capturing AFB1 and showed fluorescence intensity alteration simultaneously, enabling a dual adsorption-response mode. Deriving from the inherent porous structure of the hybrid membrane and the absorptive/responsive ability of the loaded MOF, a filtration-enhanced detection mode was elaborated to provide a 1.67-fold signal increase compared with the conventional soaking method. Therefore, the hybrid membrane exhibited a rapid response time of 10 min and a low detection limit of 0.757 ng mL-1, superior to most analogues in rapidity and sensitivity. The hybrid membrane also presented superior specificity, reproducibility, and anti-interference ability and even performed well in extreme environments such as strong acid or alkaline, satisfying the practical requirements for facile and in-field detection. Therefore, the membrane had strong applicability in chicken feed samples, with a detection recovery between 70.6% and 101%. The hybrid membrane should have significant prospects in the rapid and in-field inspection of mycotoxins for agriculture and food.

RETRACTED: Extended ocular delivery of latanoprost from niosome-laden contact lenses: In vitro characterization and in vivo studies

Glaucoma affecting the socioeconomic status of patients is currently managed by eye drop solutions, which are highly inefficient due to low ocular bioavailability. Contact lenses can be used to extend the release of ophthalmic drugs. However, the conventional soaking method showed low drug uptake and high burst release, and the optophysical properties of the contact lens were altered for clinical application. In this study, novel latanoprost-loaded niosomes were developed to increase the latanoprost loading capacity of contact lenses while also sustaining ocular drug delivery. Latanoprost-loaded niosomes were prepared by the thin film hydration technique with three levels of cholesterol. The niosome-laden lenses (SM-LT-N-CL) led to improved swelling, transmittance, oxygen permeability and lysozyme adherence of the lens compared to the conventional soaked lens (LT-SM-CL). The in vitro drug release data of LT-SM-CL (up to 24 h) showed high burst release, while SM-LT-N-CL batches showed prolonged release up to 48–96 h. In a rabbit model study, the SM-LT-N-150-CL batch showed a high drug concentration at all time points compared to the LT-SM-CL and eye drop solution. The SM-LT-N-150-CL lens was found to be safe based on histopathological studies. The study demonstrated the successful delivery of latanoprost from a niosome-laden contact lens for an extended period of time without altering the optophysical properties of the contact lens.

RETRACTED ARTICLE: Ofloxacin-Loaded Niosome-Laden Contact Lens: Improved Properties of Biomaterial for Ocular Drug Delivery

Currently, bacterial conjunctivitis is managed by multiple antibiotic eye-drop solution, which is highly inefficient due to low ocular bioavailability and frequent dosing. Therapeutic soft contact lenses can be used to sustain the release of ocular drugs. However, the conventional soaking method (economic and widely used) showed low drug uptake and high burst release, and the optophysical properties of the contact lens were altered for clinical application. In this paper, novel ofloxacin-loaded niosomes were developed to increase the drug loading capacity of contact lenses while also sustaining ocular drug delivery. Ofloxacin-loaded niosomes were prepared by the thin film hydration technique with three levels of cholesterol. The niosome-laden contact lenses (OFL-Nio-L) led to improved optophysical properties (swelling, transmittance, oxygen permeability) and lysozyme adherence compared to the conventional soaked contact lens (CV-OFL-L). The in vitro drug release data of CV-OFL-L showed high burst release, while OFL-Nio-L lenses showed sustained release up to 48-96h. In a rabbit tear fluid model, the OFL-Nio-100-L lens showed a high drug concentration at all-time points compared to the CV-OFL-L and eye-drop solution. The efficacy study in the rabbit model showed improved healing effect with OFL-Nio-100-L lens compared to frequent eye-drop therapy. In conclusion, the paper demonstrated the successful application of niosomes to deliver ofloxacin using contact lens without affecting the critical lens properties to substitute eye-drop therapy.

Sustained latanoprost release from PEGylated solid lipid nanoparticle-laden soft contact lens to treat glaucoma

Contact lens have been proposed as a mean of ocular drug delivery, but the conventional soaking method to load hydrophobic drugs, such as latanoprost shows low drug loading and high burst release with alteration in the critical lens properties. In this paper, a novel latanoprost-loaded PEGylated solid lipid nanoparticles (LP-pSLNs) were developed to increase the latanoprost loading capacity of contact lenses (LP-pSLN-L), while also sustaining ocular drug delivery. The pSLNs were spherical in shape with an average size of 105‒132 nm (nanometer) and a zeta potential ranging from ‒29.1 to ‒26.7 mV (millivolt). The LP-pSLNs led to improved swelling, transmittance, and protein adherence of the lens compared to the non-pegylated SLNs congeners (LP-SLN-L) and conventional soaked lens (LP-SM-L). The LP-SM-L lens showed low drug loading, high burst release, and a short release duration of 24 h. The LP-SLN-L and LP-pSLN-L lenses showed high drug uptake and sustained drug release up to 120 h and 96 h, respectively. The pegylation reduced the size of nanoparticles and improved the drug loading capacity, while the release rate was high in the initial hours. The LP-pSLN-L lens was found to be safe based in histopathological studies. In animal studies, the LP-pSLN-10-L batch showed high drug concentration at all-time points up to 96 h compared to the LP-SM-L and eye drop solution. In conclusion, pSLNs improved the latanoprost loading in the contact lens and showed sustained drug release, and thus can be used as a substitute to eye drop therapy.

Improvement in photovoltaic efficiency of solar cells with ZnO nanorods and electrophoretically-adsorbed dyes

ZnO nanorods grown on the F-doped tin oxide glass by a chemical bath deposition were sensitized by the electrophoretic technique or the conventional soaking method, and the resulting electrodes were applied to photoanodes of dye-sensitized solar cells (DSSCs). The DSSC with an electrophoretically-sensitized ZnO layer showed an increase in both the short-circuit current (Jsc ) and the open-circuit voltage (Voc ), resulting in a 220% enhancement of photovoltaic performance, when compared to that of the reference cell with a conventionally-sensitized ZnO layer. By applying the electrophoresis to dye adsorption, dye-loading amount was considerably increased, and thereby enhancing the light harvesting efficiency and reducing the interfacial charge recombination between photoinjected electrons and I3 −. This led to the enhancement in Jsc and Voc , compared to those of the reference cell.

Sustained Delivery of Timolol Using Nanostructured Lipid Carriers-Laden Soft Contact Lenses.

The contact lens prepared by the conventional soaking method using timolol-soaking solution showed poor drug uptake and high burst release with altered critical lens properties. In this study, timolol-loaded nanostructured lipid carriers (NLCs) were prepared and evaluated for enhanced timolol uptake and sustained release for the effective management of glaucoma. The characterization studies indicated that timolol-loaded NLCs were spherical in shape with an average size of 130-138 nm and a zeta potential of -46.6 to 51.3 mV. Critical lens properties such as swelling, optical transmittance, and protein adherence were improved with NLC-laden lenses compared to the conventional soaked lenses (SM-TB). Moreover, SM-TB lens showed low timolol uptake, high burst release, and short release duration up to 24 h compared to timolol-NLC-laden lens that showed high timolol uptake, and the cumulative release was sustained up to 96 h. The ability to sustain timolol release improved proportionally with an increase in the amount of Capmul MCMC8 (liquid lipid) in NLCs. In addition, NLC-laden lens was found to be safe according to the results of ocular irritation and histopathological studies. In the rabbit tear fluid model, NLC-30%-Cap-CL batch showed high timolol concentration at all time points up to 60 h. Further, pharmacodynamic study showed sustained reduction in IOP by NLC-30%-Cap-CL batch for 96 h compared to 48 h and 6 h with SM-TB lens and eye drop solution, respectively. In conclusion, NLCs enhanced timolol uptake in the contact lens from the soaking solution using soaking method with improved in vitro and in vivo results for better clinical outcomes in the patients with glaucoma.

Sustained bimatoprost release using gold nanoparticles laden contact lenses

Contact lenses are ideally suited for sustained ocular drug delivery to bypass the issues associated with eye drop therapy. However, drugs such as bimatoprost loaded by the conventional soaking method show poor drug uptake, high burst release, and altered critical lens properties. In this study, the effect of gold nanoparticles (GNPs) on bimatoprost loading/uptake from the soaking solution and its release kinetics from the lens was investigated. In one method, GNP solutions of varying strength were loaded into the bimatoprost soaking solution (mM-SS batches), and in another method, the GNPs were included in the contact lens matrix during casting (mM-GN-L batches). The GNPs were spherical with average size of 21.1 nm and −20.1 mV zeta potential. The swelling, oxygen permeability, and optical transmittance of the lens were improved compared to those of the lens drug-loaded by the conventional soaking method (SM-L). The mM-GN-L batches showed significant improvement in drug uptake from the soaking solution compared to the SM-L and mM-SS batches. The in vitro studies showed relatively low burst and sustained bimatoprost release up to 72 h compared to 24 h with the SM-L batch. The ability to sustain drug release improved proportionally with an increase in the amount of GNPs in the lens. The presence of GNPs lowered protein adherence. The GNP-laden lenses were deemed safe in ocular irritation and histopathology reports (rabbit model). Further, they showed higher drug retention in the rabbit tear fluid compared to the SM-L lens. In conclusion, the presence of GNPs in contact lenses increased drug uptake from the soaking solution, and improved the in vitro and in vivo release kinetics without affecting the critical properties of the contact lenses for therapeutic application.

Programmed BMP-2 release from biphasic calcium phosphates for optimal bone regeneration

This study aimed to fabricate a multi-layered biphasic calcium phosphate (BCP) platform for programmed bone morphogenetic protein-2 (BMP-2) release, which means to block the initial burst release and promote releasing during the differentiation phase of osteogenic cells. And it is to confirm in vivo whether this platform has osteogenic inductivity even when extremely low doses of BMP-2 are loaded compared to the conventional soaking method. Our strategy consisted of preparing a multilayer coating on BCP to minimize the contact between BMP-2 and BCP and allow the loading of BMP-2. The multilayer, which is surface-modified on BCP, is composed of an organosilicate and a natural polymer-based layer-by-layer (LbL) film. We applied (3-Aminopropyl)triethoxysilane (APTES) as an organosilicate was used for amine-functionalized BCP and (collagen/heparin)5 film was used to delay and sustain BMP-2 release. The coated multilayer not only reduced the initial burst release by more than 50% but also loaded more BMP-2. For in vivo experiment, histomorphometric analysis, it was observed that the BCP platform loaded with extremely low concentration BMP-2 (0.01 mg/ml) induced a significantly larger amount of new bones at 8 weeks compared to the conventional soaking method in the rabbit calvarium onlay graft model.

One-step electrodeposition synthesis of bisphosphonate loaded magnesium implant: A strategy to modulate drug release for osteoporotic fracture healing

Osteoporotic fracture with increase of aging population became an urgent orthopedic problem. Bisphosphonates were widely recommended as effective clinical treatment drugs. Combination of biodegradable Mg-based implants and merits of bisphosphonates was suggested for osteoporotic fracture healing. Considering the mild and sustained drug release, a novel one-step electrodeposition synthesis of drug loaded coating was proposed in this study. In comparison to conventional soaking method, encapsulated zoledronate coating by one-step electrodeposition method could modulate drug release in first diffusion-controlled and later degradation-controlled manner. The in vitro cell response to zoledronate loaded coating showed enhanced proliferation and osteogenic differentiation of osteoblasts and no significant inhibition on osteoclasts, which could improve bone-forming and decrease bone resorption due to osteoporosis.

Hyaluronic acid and graphene oxide loaded silicon contact lens for corneal epithelial healing

Hyaluronic acid (HA) eye drop solution is widely used to treat and manage various corneal diseases like keratoconus (after corneal cross-linking) and dry eye syndrome. However, ocular dosage forms like eye drop solution affect the routine life style of patients due to frequent dosing schedule. In this study, HA and reduced graphene oxide (rGO) was directly loaded in the silicon contact lenses (HA-GO-DL) and compared with the conventional soaking method (HA-GO-SM). The contact lenses at lower level of rGO showed permissible swelling and transmittance properties. The water retention property of HA-GO-DL contact lenses was confirmed by water evaporation studies. The flux data of HA-GO-SM contact lenses showed high burst release with 24 h release duration. While, HA-GO-DL lenses confirmed low burst with sustained release up to 96 h. In ocular irritation study, the HA-GO-DL-2 lenses was found to be safe. The HA-GO-DL-2 batch showed high HA-tear fluid concentration (rabbit model) and improvement in the rabbit tear fluid volume (Schirmer strip studies) in comparison to the soaking method (HA-GO-SM-2) and eye drop solution. The study successfully demonstrate the potential of HA-GO loaded contact lenses to improve tear fluid volume to manage various ocular diseases like dry eye syndrome.

RETRACTED: Ketotifen loaded solid lipid nanoparticles laden contact lens to manage allergic conjunctivitis

Contact lenses are idea medical device to sustain the release of anti-allergic ocular drugs like ketotifen along with added advantage to act as a physical barrier against airborne antigens. However, the conventional soaking method using ketotifen-packaging solution showed low drug uptake, high burst release and short release duration along with reduction in the optical transmittance and swelling properties of the contact lens. In this paper, ketotifen loaded pegylated solid lipid nanoparticles (p-SNLs) laden contact lenses were fabricated to overcome the issues related to eye drop solution (frequent instillation) and contact lens. The SLNs and p-SLNs soaked contact lenses showed high drug uptake and did not changed the optical, swelling and oxygen permeability of the contact lenses. The in vitro release data of the soaked contact lenses (SM-K) showed low drug uptake and short release duration (48 h). The SLNs/p-SLNs soaked contact lenses showed improved drug uptake and sustain ketotifen release up to 72–96 h. The most promising results were shown by direct SLNs/p-SLNs laden contact lenses, which showed sustain release up to 168–192 h (with low burst release). The contact lens was safe in ocular irritation studies and showed high tear ketotifen-concentration (rabbit eye model) in comparison to the eye drop solution. The work demonstrated the promising potential of pegylated solid lipid nanoparticles to deliver ketotifen without compromising the critical contact lens properties to treat and manage various ocular allergic conditions.

Ofloxacin laden microemulsion contact lens to treat conjunctivitis

Currently, conjunctivitis is treated using ofloxacin eye drop solution, which shows low bioavailability and patient non-compliance. Ofloxacin loaded contact lens can be used to overcome the issues related to eye drop solutions (i.e. low bioavailability and frequent instillation). However, the conventional soaking method shows poor ofloxacin uptake and significantly affect the swelling and optical properties of the contact lenses. The current research investigates the effect of microemulsion on the ofloxacin uptake and its effect on the physical properties of the contact lens along with ofloxacin-release kinetics. In comparison to the conventional soaking method (Of-SM, ofloxacin-packaging solution), the ofloxacin loaded microemulsion-soaked contact lenses (Of-ME) showed improved drug uptake and physical properties of the contact lenses. The in vitro release data of Of-ME contact lenses showed 72–120 h release profile, while Of-SM contact lenses showed 24–60 h. The in vivo drug release data in the tear fluid (New Zealand rabbit’s eye) showed high ofloxacin retention in comparison to the eye drop solution. The efficacy study in the rabbit model showed equivalent healing effect with the Of-ME contact lens in comparison to the frequent high dose eye drop therapy. Thus, the study demonstrates the application of microemulsion system to improve the ofloxacin loading capacity in the contact lens along with improvement in the physical properties to treat conjunctivitis.

Travoprost loaded microemulsion soaked contact lenses: Improved drug uptake, release kinetics and physical properties

Currently, travoprost is delivered by eye drop solution (glaucoma management), which shows very low bioavailability and patient non-compliance. Drug loaded contact lenses can be used to bypass the limitations of dosage by eye drops (low bioavailability and frequent instillation). However, the conventional soaking method (via drug-packaging solution) shows poor travoprost uptake and significantly affects the swelling and optical properties of the contact lenses. The current research investigated the effect of a stable microemulsion system on travoprost uptake and its effect on the physical properties of contact lenses along with drug-release kinetics. In comparison to the conventional soaking method (T-SM, travoprost-packaging solution), the travoprost loaded microemulsion soaked contact lenses (T-ME) showed improved drug uptake (loading) and physical properties of the contact lenses. The flux data (in vitro release) of T-ME contact lenses had a slower, 48–120 h, release profile, compared to T-SM contact lenses (36–48 h). The in vivo drug release data in the tear fluid (New Zealand rabbit's eye) showed high drug retention in comparison to eye drop solution. Thus, the study demonstrates the application of microemulsion system to improve the travoprost loading capacity in the contact lens along with improvement in the swelling and optical transmittance properties.

Total phenolic content and antioxidant activity of Pandanus amaryllifolius by soaking and microwave-assisted extraction

Many studies have reported on the limitation of conventional extraction methods. Therefore, this work aims to compare the effects of conventional soaking extraction and microwave-assisted extraction (MAE) on the total phenolic content (TPC) and antioxidant activity of Pandanus amaryllifolius leaves. For soaking method, the pandan leaves were soaked in various ethanol-water mixture (50, 75 and 100%) at different temperatures (40, 50, 60, 70°C) for 10 minutes. Meanwhile for MAE method, the pandan leaves were extracted in the same concentrations of ethanol-water and subjected to different microwave power level (100, 180, 300, 450, 600 and 850W) for 10 minutes. It was found that MAE resulted in higher yield of TPC (1.557 mg/g gallic acid equivalent) compared to conventional soaking method (0.979 mg/g gallic acid equivalent). MAE could remarkably retain bioactive total phenolic content and antioxidant activity and has huge potential and application in the food industry.

Bimatoprost Imprinted Silicone Contact Lens to Treat Glaucoma.

Bimatoprost is widely used for the management of glaucoma. Currently, it is delivered via eye drop solution, which is highly inefficient due to low bioavailability. To control the release of ocular drugs, contact lenses are used by scientists. However, the conventional soaking method showed high burst release due to absence of any efficient controlling membrane. The objective of the paper was to apply molecular imprinting technology to improve the loading of bimatoprost from the soaking solution and to sustain the release of drug from the contact lens. The bimatoprost was loaded by conventional soaking method (BT-SM) and compared with the molecular imprinted contact lenses (BT-MP). The loading of bimatoprost by molecular imprinting technology affect the swelling of the contact lens; however, the batch BT-MP-10 did not showed significant alterations. The uptake study showed improvement in the bimatoprost loading by molecular imprinting technology in comparison to the conventional soaking technology. The in vitro bimatoprost release data showed improvement in the bimatoprost release rate profiles with BT-MP contact lenses (up to 36-60h) lenses in comparison to BT-SM contact lenses (up to 24-36h). The in vivo rabbit tear fluid data with BT-MP batch showed improvement in the bimatoprost retention time in comparison to BT-SM contact lens and eye drop solution. The rabbit model failed to respond bimatoprost; thus, the efficacy studies need to be conducted on canines or human primates. The paper revealed the potential of using molecular imprinting technology to improve the uptake of bimatoprost and to achieve sustain release kinetics without altering the swelling, transmittance and folding endurance properties of the contact lens.

Effect of gold nanoparticles on timolol uptake and its release kinetics from contact lenses: In vitro and in vivo evaluation

Contact lenses are ideally suited for extended drug delivery to the ocular tissues, but incorporation of any particulate system affects the critical properties of the contact lens. Timolol loading by the conventional soaking method does not significantly alter the critical properties of the contact lens. However, there are challenges of low drug loading and high burst release. This research work aimed to investigate the effect of gold nanoparticles (GNPs) on loading and its release kinetics from the contact lens using the soaking method. In one approach, GNPs were loaded into the timolol soaking solution (GNPs-SS), and in another approach, GNPs were incorporated into the contact lenses (GNPs-CL) during fabrication. The contact lenses were soaked at two different concentrations of timolol (i.e., 2 mg/ml and 4 mg/ml). Swelling and optical transmittance were not significantly affected by the presence of GNPs in the contact lenses. A significant uptake/loading of timolol using the GNPs in both the approaches was observed. The in vitro flux data showed no significant improvement in the release rate profiles of timolol when using both approaches. However, the in vivo study in the rabbit tear fluid showed high timolol concentration with the GNPs-laden contact lens at all timepoints in comparison to the soaked contact lenses without GNPs. The in vivo pharmacodynamic study in rabbits showed a 2 mmHg average fall in intraocular pressure (72 h) using the GNPs-laden contact lenses, while the soaked contact lenses without GNPs and eye drops solution (0.5 %w/v) showed 2 mmHg. The drug distribution study in the ocular tissue showed a significant improvement in the drug deposition with the GNPs-laden contact lenses in the ciliary muscle and conjunctiva. This study successfully demonstrated the potential of GNPs to enhance the uptake of drug from the drug soaking solution to treat glaucoma without compromising the critical properties of contact lens. Statement of SignificanceIn this study, we have overcome the limitation of the conventional soaking method of low drug loading and high burst release from the contact lenses. We have investigated the effect of gold nanoparticles (GNPs) on the timolol loading and its release kinetics from the contact lenses. The study revealed the potential of GNPs to enhance the uptake of timolol from the timolol soaking solution to treat glaucoma without compromising the critical lens properties.

Optimized extraction of artemisinin fromArtemisia annuaL. and corroborated quantitative analysis using high-performance thin-layer chromatography

An optimized method for the extraction and quantification of artemisinin using high-performance thin-layer chromatography (HPTLC) from dried Artemisia annua L. leaf was established. Seven solvents with different polarities were used for the efficient extraction of artemisinin by hot Soxhlet as well as by conventional soaking method at room temperature. Among these solvents, n-hexane was found to be the superior solvent for both extraction methods. The chromatographic separation was carried out on precoated silica gel plate G60 F254 using n-hexane-ethyl acetate-acetic acid (2:1:0.1) as the mobile phase, and densitometric analysis was carried out in absorbance mode at 540 nm after derivatization with anisaldehyde spraying reagent. The HPTLC method was validated for specificity as well as for recovery. The optimized mobile phase gave well-defined peaks of artemisinin at Rf value of 0.43 ± 0.006. The linear regression analysis of the calibration plots using standard artemisinin exhibited good linear relations...

Crystallographic Snapshots of an Entire Reaction Cycle for a Retaining Xylanase from Streptomyces olivaceoviridis E-86

Retaining glycosyl hydrolases, which catalyse both glycosylation and deglycosylation in a concerted manner, are the most abundant hydrolases. To date, their visualization has tended to be focused on glycosylation because glycosylation reactions can be visualized by inactivating deglycosylation step and/or using substrate analogues to isolate covalent intermediates. Furthermore, during structural analyses of glycosyl hydrolases with hydrolytic reaction products by the conventional soaking method, mutarotation of an anomeric carbon in the reaction products promptly and certainly occurs. This undesirable structural alteration hinders visualization of the second step in the reaction. Here, we investigated X-ray crystallographic visualization as a possible method for visualizing the conformational itinerary of a retaining xylanase from Streptomyces olivaceoviridis E-86. To clearly define the stereochemistry at the anomeric carbon during the deglycosylation step, extraneous nucleophiles, such as azide, were adopted to substitute for the missing base catalyst in an appropriate mutant. The X-ray crystallographic visualization provided snapshots of the components of the entire reaction, including the E*S complex, the covalent intermediate, breakdown of the intermediate and the enzyme-product (E*P)complex.

Effect of soaking and gaseous treatment on GABA content in germinated brown rice

To establish a new method of processing germinated brown rice (GBR), we processed grain of cultivars with a large germ by soaking and gaseous treatment. After soaking for 3 h and gaseous treatment for 21 h at 35 °C, the content of γ-aminobutyric acid (GABA) in GBR (24.9 mg/100 g) was higher than that by the conventional soaking method (10.1 mg/100 g). Although the number of microorganisms on the surface of the GBR increased during soaking, steaming for 20 min and ethanol treatment for 3 min completely sterilized the GBR and did not reduce the amount of GABA.