scholarly journals Adsorption and Sustained Delivery of Small Molecules from Nanosilicate Hydrogel Composites

2022 ◽  
Vol 15 (1) ◽  
pp. 56
Author(s):  
Samuel Stealey ◽  
Mariam Khachani ◽  
Silviya Petrova Zustiak
Keyword(s):  
Small Molecules ◽  
High Surface ◽  
High Surface Area ◽  
Control Release ◽  
Mesh Size ◽  
Burst Release ◽  
Prolonged Release ◽  
Nanocomposite Hydrogels ◽  
Small Molecule Therapeutics ◽  
And Control

Two-dimensional nanosilicate particles (NS) have shown promise for the prolonged release of small-molecule therapeutics while minimizing burst release. When incorporated in a hydrogel, the high surface area and charge of NS enable electrostatic adsorption and/or intercalation of therapeutics, providing a lever to localize and control release. However, little is known about the physio-chemical interplay between the hydrogel, NS, and encapsulated small molecules. Here, we fabricated polyethylene glycol (PEG)-NS hydrogels for the release of model small molecules such as acridine orange (AO). We then elucidated the effect of NS concentration, NS/AO incubation time, and the ability of NS to freely associate with AO on hydrogel properties and AO release profiles. Overall, NS incorporation increased the hydrogel stiffness and decreased swelling and mesh size. When individual NS particles were embedded within the hydrogel, a 70-fold decrease in AO release was observed compared to PEG-only hydrogels, due to adsorption of AO onto NS surfaces. When NS was pre-incubated and complexed with AO prior to hydrogel encapsulation, a >9000-fold decrease in AO release was observed due to intercalation of AO between NS layers. Similar results were observed for other small molecules. Our results show the potential for use of these nanocomposite hydrogels for the tunable, long-term release of small molecules.

scholarly journals Fabrication of a Reservoir Ring for Sustained and Prolonged Release of Levonorgestrel for Vaginal Administration

2020 ◽  
Author(s):  
Fateme Hosseinzade ◽  
Hadi Tabesh ◽  
Farah Farzaneh
Keyword(s):  
Drug Loading ◽  
Abnormal Uterine Bleeding ◽  
Weight Percent ◽  
Good Choice ◽  
Burst Release ◽  
Prolonged Release ◽  
Suitable Alternative ◽  
Vaginal Rings ◽  
Spss Software ◽  
And Control

Introduction: More than one-third of women experience abnormal uterine bleeding (AUB) during their lifetime. One of the treatment methods of this disease is hormone therapy. Vaginal rings (VRs) containing progesterone hormones could be a good choice for treatment. In this study, the design and construction of a reservoir ring with the ability to release levonorgestrel hormone has been investigated. Methods: In this experimental study, to make vaginal rings containing levonorgestrel, biocompatible silicone fibers were used, the two ends of which were connected with special caps. Different amounts of LNG including 0.1, 0.2 and 0.4 weight percent relative to paraffin were loaded into the fibers. These three prototypes were named RSC1, RSC2, and RSC3, respectively. The daily and cumulative release of LNG from these rings was measured by spectrophotometer and compared using SPSS software version 16 and analyzed by one-way ANOVA method. Results: On the first day, there was a burst release that was different for these three prototypes depending on the drug loading percentage. From the second until thirtieth day for RSC3 and from forth until thirtieth day for RSC1 and RSC2, prolonged release was achieved and average daily release for RSC1, RSC2, and RSC3 were 24.10 ± 8.22, 41.77 ± 9.02 and 83.29 ± 5.07µg, respectively. Conclusion: According to the findings, it is possible to design VRs capable of prolonged and sustained release of LNG for up to 30 days and control their daily release rate based on initial drug loading. This method may be a suitable alternative to oral hormonal pills in the treatment of AUB.

Controlled Growth of Imine-Linked Two-Dimensional Covalent Organic Framework Nanoparticles

2019 ◽  
Author(s):  
Rebecca Li ◽  
Nathan C. Flanders ◽  
Austin Evans ◽  
Woojung Ji ◽  
Ioannina Castano ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Particle Growth ◽  
Emergent Properties ◽  
Mechanistic Studies ◽  
X Ray ◽  
X Ray Scattering ◽  
Exchange Processes ◽  
And Control

Covalent organic frameworks (COFs) consist of monomers arranged in predictable structures with emergent properties. However, improved crystallinity, porosity, and solution processability remain major challenges. To this end, colloidal COF nanoparticles are useful for mechanistic studies of nucleation and growth and enable advanced spectroscopy and solution processing of thin films. Here we present a general approach to synthesize imine-linked 2D COF nanoparticles and control their size by favoring imine polymerization while preventing the nucleation of new particles. The method yields uniform, crystalline, and high-surface-area particles and is applicable to several imine-linked COFs. In situ X-ray scattering experiments reveal the nucleation of amorphous polymers, which crystallize via imine exchange processes during and after particle growth, consistent with previous mechanistic studies of imine-linked COF powders. The separation of particle formation and growth processes offers control of particle size and may enable further improvements in crystallinity in the future.

Synthesis and characterization of mesalamine silica nanoparticles

2021 ◽  
Vol 16 ◽  
Author(s):  
Balaji Maddiboyina ◽  
Ramya Krishna Nakkala ◽  
Prasanna Kumar Desu ◽  
Vikas Jhawat
Keyword(s):  
Particle Size ◽  
Silica Nanoparticles ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Silica Nanoparticle ◽  
Water Soluble ◽  
Infrared Spectrometry ◽  
Burst Release ◽  
Wide Range

Background: Nanoparticles made of silica are new materials that can be used in a wide range of drug delivery methods because they are biocompatible and biodegradable. Mesalamine, a classic water-soluble medication, remains loaded into the synthesized silica nanoparticle and is considered for sustained release proficiency. Precipitation approach using high surface area and pore volume tetraethyl orthosilicate yielded mesalamine-loaded silica nanoparticles. Methods: The drug-loaded nanoparticle was created and produced using two different techniques. Fourier transform infrared spectrometry, differential scanning calorimetry, X-ray powder diffraction, Brauer Emmett teller, scanning electron microscopy, particle size measurements, and dissolution investigations have all been used to analyse the substance in some way or another. Results: Because of the high surface area, well-known results like the complete silica nanoparticle created using method-2 remained mesoporous. The onset peak of the method-2 formulation's DSC was 182.27°c, and the offset peak was 192.14°c, consistent with the DSC results. The particle size range varies from 205-225nm. The results demonstrate that the uptake of the mesalamine by burst release it for 30 minutes initial, followed by sustained maintenance of dose even after 240 minutes. The results indicate that the loading process has an effect on the extent of loading. When silica nanoparticles were impregnated with mesalamine, the amount of the drug contained was significantly higher than when they were wetted. Conclusion: In addition, the XRD results show that both the pure mesalamine and the formulation did not show any polymorphic deviation.

Electroconductive and electroresponsive membranes for water treatment

2016 ◽  
Vol 32 (5) ◽  
Author(s):  
Avner Ronen ◽  
Sharon L. Walker ◽  
David Jassby
Keyword(s):  
Membrane Filtration ◽  
High Efficiency ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Membrane Properties ◽  
Electrochemical Reactions ◽  
Permeate Flux ◽  
Inorganic Matter ◽  
And Control

AbstractIn populated, water-scarce regions, seawater and wastewater are considered as potable water resources that require extensive treatment before being suitable for consumption. The separation of water from salt, organic, and inorganic matter is most commonly done through membrane separation processes. Because of permeate flux and concentration polarization, membranes are prone to fouling, resulting in a decline in membrane performance and increased energy demands. As the physical and chemical properties of commercially available membranes (polymeric and ceramic) are relatively static and insensitive to changes in the environment, there is a need for stimuli-reactive membranes with controlled, tunable surface and transport properties to decrease fouling and control membrane properties such as hydrophilicity and permselectivity. In this review, we first describe the application of electricity-conducting and electricity-responsive membranes (ERMs) for fouling mitigation. We discuss their ability to reduce organic, inorganic, and biological fouling by several mechanisms, including control over the membrane’s surface morphology, electrostatic rejection, piezoelectric vibrations, electrochemical reactions, and local pH changes. Next, we examine the use of ERMs for permselectivity modification, which allows for the optimization of rejection and control over ion transport through the application of electrical potentials and the use of electrostatically charged membrane surfaces. In addition, electrochemical reactions coupled with membrane filtration are examined, including electro-oxidation and electro-Fenton reactions, demonstrating the capability of ERMs to electro-oxidize organic contaminates with high efficiency due to high surface area and reduced mass diffusion limitations. When applicable, ERM applications are compared with commercial membranes in terms of energy consumptions. We conclude with a brief discussion regarding the future directions of ERMs and provide examples of several applications such as pore size and selectivity control, electrowettability, and capacitive deionization. To provide the reader with the current state of knowledge, the review focuses on research published in the last 5 years.

scholarly journals Domain-selective thermal decomposition within supramolecular nanoribbons

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yukio Cho ◽  
Ty Christoff-Tempesta ◽  
Dae-Yoon Kim ◽  
Guillaume Lamour ◽  
Julia H. Ortony
Keyword(s):  
Thermal Decomposition ◽  
Small Molecules ◽  
Self Assembly ◽  
High Surface ◽  
High Surface Area ◽  
Molecular Organization ◽  
Energy Applications ◽  
Packing Parameter ◽  
Parameter Constraints ◽  
Surface Chemistries

AbstractSelf-assembly of small molecules in water provides a powerful route to nanostructures with pristine molecular organization and small dimensions (<10 nm). Such assemblies represent emerging high surface area nanomaterials, customizable for biomedical and energy applications. However, to exploit self-assembly, the constituent molecules must be sufficiently amphiphilic and satisfy prescribed packing criteria, dramatically limiting the range of surface chemistries achievable. Here, we design supramolecular nanoribbons that contain: (1) inert and stable internal domains, and (2) sacrificial surface groups that are thermally labile, and we demonstrate complete thermal decomposition of the nanoribbon surfaces. After heating, the remainder of each constituent molecule is kinetically trapped, nanoribbon morphology and internal organization are maintained, and the nanoribbons are fully hydrophobic. This approach represents a pathway to form nanostructures that circumvent amphiphilicity and packing parameter constraints and generates structures that are not achievable by self-assembly alone, nor top-down approaches, broadening the utility of molecular nanomaterials for new targets.

scholarly journals New Candidate Delivery System for Alzheimer’s Disease: Deferoxamine Nanogels

2020 ◽  
Vol 10 (6) ◽  
pp. 7106-7119
Keyword(s):  
Small Molecules ◽  
Iron Chelation ◽  
Control Release ◽  
Optimum Conditions ◽  
Spherical Structure ◽  
Loading Ratio ◽  
Loading Amount ◽  
And Control ◽  
Uniform Particle Size

This study presents hydrogel nanoparticles made of chitosan and tripolyphosphate via ionotropic gelation technique to evaluate their potential for the association of deferoxamine. Since it has been shown that iron chelation therapy can be useful in the treatment of some neurodegenerative diseases such as Alzheimer's, in this study, we attempted to evaluate the in vitro characteristics of deferoxamine-loaded nanogels for this purpose. Chitosan-based nanogels were prepared and optimized in terms of size by a Taguchi Orthogonal Array design. The spherical structure nanoparticles showed a uniform particle size of 63±2 nm with loading amount, Loading efficiency, and loading ratio of 8.48%±0.021, 26.1%±0.63, and 2.66%±1.88 respectively in optimum conditions. Further study revealed that this nanoparticulate system can be a suitable carrier for the entrapment and control release of small molecules such as deferoxamine.

scholarly journals Transition Metal Dichalcogenides (TMDC)-Based Nanozymes for Biosensing and Therapeutic Applications

Materials ◽  
2022 ◽  
Vol 15 (1) ◽  
pp. 337
Author(s):  
Dario Presutti ◽  
Tarun Agarwal ◽  
Atefeh Zarepour ◽  
Nehar Celikkin ◽  
Sara Hooshmand ◽  
...  
Keyword(s):  
Transition Metal ◽  
High Surface ◽  
High Surface Area ◽  
Transition Metal Dichalcogenides ◽  
Enzymatic Properties ◽  
Promising Alternative ◽  
Therapeutic Applications ◽  
Semiconducting Properties ◽  
Metal Dichalcogenides ◽  
And Control

Nanozymes, a type of nanomaterial with enzyme-like properties, are a promising alternative to natural enzymes. In particular, transition metal dichalcogenides (TMDCs, with the general formula MX2, where M represents a transition metal and X is a chalcogen element)-based nanozymes have demonstrated exceptional potential in the healthcare and diagnostic sectors. TMDCs have different enzymatic properties due to their unique nano-architecture, high surface area, and semiconducting properties with tunable band gaps. Furthermore, the compatibility of TMDCs with various chemical or physical modification strategies provide a simple and scalable way to engineer and control their enzymatic activity. Here, we discuss recent advances made with TMDC-based nanozymes for biosensing and therapeutic applications. We also discuss their synthesis strategies, various enzymatic properties, current challenges, and the outlook for future developments in this field.

Controlled Growth of Imine-Linked Two-Dimensional Covalent Organic Framework Nanoparticles

2019 ◽  
Author(s):  
Rebecca Li ◽  
Nathan C. Flanders ◽  
Austin Evans ◽  
Woojung Ji ◽  
Ioannina Castano ◽  
...  
Keyword(s):  
High Surface ◽  
High Surface Area ◽  
Particle Growth ◽  
Emergent Properties ◽  
Mechanistic Studies ◽  
X Ray ◽  
X Ray Scattering ◽  
Exchange Processes ◽  
And Control

Covalent organic frameworks (COFs) consist of monomers arranged in predictable structures with emergent properties. However, improved crystallinity, porosity, and solution processability remain major challenges. To this end, colloidal COF nanoparticles are useful for mechanistic studies of nucleation and growth and enable advanced spectroscopy and solution processing of thin films. Here we present a general approach to synthesize imine-linked 2D COF nanoparticles and control their size by favoring imine polymerization while preventing the nucleation of new particles. The method yields uniform, crystalline, and high-surface-area particles and is applicable to several imine-linked COFs. In situ X-ray scattering experiments reveal the nucleation of amorphous polymers, which crystallize via imine exchange processes during and after particle growth, consistent with previous mechanistic studies of imine-linked COF powders. The separation of particle formation and growth processes offers control of particle size and may enable further improvements in crystallinity in the future.

scholarly journals In-situ Gas Dosed Powder Diffraction Under Industrially Relevant Conditions

2014 ◽  
Vol 70 (a1) ◽  
pp. C158-C158
Author(s):  
Matthew Hudson ◽  
Wendy Queen ◽  
Craig Brown
Keyword(s):  
Small Molecules ◽  
Powder Diffraction ◽  
High Pressures ◽  
High Surface ◽  
High Surface Area ◽  
Chemical Properties ◽  
Microporous Materials ◽  
Metal Organic ◽  
In Situ Diffraction

The adsorption of small molecules onto functionalized, high surface area microporous materials is important for the advancement of industrial and environmental processes ranging from catalysis and chemical separations, to CO2 sequestration and energy storage. Over the past several years we have focused our research efforts on understanding the molecular interactions of these small molecules with a variety of microporous materials using in-situ powder diffraction methods to correlate structure with chemical properties. Background will be given on the design of gas dosing apparatus for in-situ diffraction studies at synchrotron X-ray and neutron powder beamlines. The result is that accurate doses can be made per quantity of interest (moles of cations, per unit cell, per pore, etc.), or under high pressures (100 bar), and/or chemical reactions can be followed versus temperature/pressure. Several of our recent investigations of CO2/N2/CH4 sorption in cation-exchange zeolites including Zeolite A (5A) and CHA are presented. While many industrial processes use zeolites to carry out these functions, more emphasis has been placed on metal-organic frameworks (MOFs) on late since their properties can be tuned by varying the synthetic components. A number of studies on an isostructural series, M-MOF-74, have been considered investigating why certain functionalization leads to increased specificity for applications such as CO2, O2, CO, and hydrocarbon separations. The ultimate goal is to use the knowledge gained to improve the design of new MOF materials.

scholarly journals Heterogeneous Catalysis of C–O Bond Cleavage for Cellulose Deconstruction: A Potential Pathway for Ethanol Production

2014 ◽  
Vol 2014 ◽  
pp. 1-8
Author(s):  
Kristy Crews ◽  
Crystal Reeves ◽  
Porsha Thomas ◽  
Daniel Abugri ◽  
Albert Russell ◽  
...  
Keyword(s):  
Small Molecules ◽  
Surface Area ◽  
Cobalt Chloride ◽  
Bond Cleavage ◽  
High Surface ◽  
High Surface Area ◽  
Complete Separation ◽  
Metal Catalyst ◽  
Co Nanoparticles ◽  
Butyl Methyl Ether

Due to difficulty deconstructing the linkages between lignin, hemicellulose and cellulose during the conversion of cellulose to sugar, the commercial production of cellulosic ethanol is limited. This can be overcome by using a high surface-area metal catalyst. In this study, high surface-area metal NPs were synthesized using 20 mM of chloroplatinic acid and cobalt chloride prepared in THF with 0.1 mM of generation four poly(amido)amine (PAMAM) terminated dendrimer (G4-NH2) prepared in methanol and stirred for 2 hours under nitrogen. Subsequently, Pt+2 and Co+2 ions were reduced to metal zero via introduction of sodium borohydride and centrifuged for complete separation. The resulting product was heated for 2.5 hours at ~200°C. After cooling, 2.0 grams of crushed peanut shells was added to 40 mL of distilled tert-butyl methyl ether along with the separated metal nanocatalyst and refluxed on condenser at 20% for 24 hours. UV-Vis and XRD analyses show the formation of Pt and Co nanoparticles using dendrimer templating methodology. Both TLC and HPLC show that, upon introduction of the metal catalyst into the suspension of “cellulose” in TBME, separation of the cellulose into small molecules is evident. That is, release of sugar molecules via C–O bond cleavage is facilitated by the formed nanocatalysts.

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