Morin Flavonoid Adsorbed on Mesoporous Silica, a Novel Antioxidant Nanomaterial

Encapsulation of debittered pomelo juice using novel Moringa oleifera exudate for enrichment of yoghurt: A techno-functional approach

Debittering of pomelo juice was conducted using 3.7 g of activated resin, resulting in a 36.8% reduction in bitterness without affecting the bioactive properties of juice. The debittered juice was then encapsulated with Moringa oleifera exudate at various ratios (1-5%), yielding a powder with a slightly rough surface. Total phenol content (TPC) increased by 46-56% compared to the debittered juice. Functional yoghurt containing encapsulates at concentrations of 1% and 2% demonstrated that the 2% concentration led to longer storage duration, resulting in increased acidity and syneresis compared to the control. TPC of the yoghurt (161.89-198.22 μg Gallic acid equivalent (GAE)/g) remained significantly higher (p < 0.05) than that of the control (47.15 μg GAE/g) and acacia gum-based yoghurt (141.89-171.37 μg GAE/g), decreasing with storage duration. Addition of encapsulates significantly altered the yoghurt's texture, resulting in lower firmness (0.57 to 0.64 N) compared to the control, while adhesiveness values remained comparable (6.33 to 6.25 g.s). The highest values of G' and G" were observed in samples containing 2% encapsulates with moringa compared to those with acacia gum. This study suggests potential avenues for further exploration in functional foods with enhanced health benefits.

Epigallocatechin-3-gallate adsorbed on core-shell gold nanorod@mesoporous silica nanoparticles, an antioxidant nanomaterial with photothermal properties

Epigallocatechin-3-gallate (EGCG) exhibits several pharmacological activities with potential benefits for human health, however, it has low oral bioavailability. A promising approach is to transport EGCG in a nanostructured system to protect it until it reaches the site of action and also allow combining chemotherapy with phototherapy to improve its therapeutic efficiency. The aim of this work was to synthesize GNR@mSiO2-NH2/EGCG and characterize the adsorption process, its antioxidant activity, properties and photothermal stability, for its potential use in chemo-photothermal therapy. The nanosystem presented good encapsulation efficiency (19.2 %) and EGCG loading capacity (6.0 %). The DPPH• free radical scavenging capacity (RSA) and chelating activity of the nanosystem was 60.7 ± 6.9 % and 71.0 ± 6.4 % at an EGCG equivalent concentration of 1 µg/mL and 30 µg/mL, respectively. The core-shell NPs presented a good photothermal transduction efficiency of 17 %. EGCG free, as well as its RSA and chelating activity, remained stable after NIR irradiation (808 nm, 7 W/cm2). The morphology of GNR@mSiO2 remained intact after being irradiated with NIR, however, ultrasmall gold NPs could be observed, probably a product of photocracking of GNR. In summary, the nanosystem has good antioxidant activity, photothermal stability, and photothermal transduction ability making it potentially useful for chemo-photothermal therapy.

A pH-sensitive silica nanoparticles for colon-specific delivery and controlled release of catechin: Optimization of loading efficiency and in vitro release kinetics

Catechin is a naturally occurring flavonoid of the flavan-3-ol subclass with numerous biological functions; however, these benefits are diminished due to several factors, including low water solubility and degradation in the stomach's harsh environment. So, this study aimed to develop an intelligent catechin colon-targeting delivery system with a high loading capacity. This was done by coating surface-decorated mesoporous silica nanoparticles with a pH-responsive enteric polymer called Eudragit®-S100. The pristine wormlike mesoporous silica nanoparticles (< 100 nm) with high surface area and large total pore volume were effectively synthesized and modified with the NH2 group using the post-grafting strategy. Various parameters, including solvent polarity, catechin-carrier mass ratio, and adsorption time, were studied to improve the loading of catechin into the aminated silica nanoparticles. Next, the negatively charged Eudragit®-S100 was electrostatically coated onto the positively charged aminated nanocarriers to shield the loaded catechin from the acidic environment of the stomach (pH 1.9) and to facilitate site-specific delivery in the acidic environment of the colon (pH 7.4). The prepared nanomaterials were evaluated using several methods, including The Brauner-Emmett-Teller, surface area analyzer, zeta sizer, Field Emission Scanning Electron Microscope, Powder X-Ray Diffraction, Fourier Transform Infrared Spectroscopy, Energy-Dispersive X-ray Spectroscopy, and Differential Scanning Calorimetry. In vitro dissolution studies revealed that Eudragit®-S100-coated aminated nanomaterials prevented the burst release of the loaded catechin in the acidic environment, with approximately 90% of the catechin only being released at colonic pH (pH > 7) with a supercase II transport mechanism. As a result, silica nanoparticles coated with Eudragit®-S100 would provide an innovative and promising approach in targeted nanomedicine for the oral delivery of catechin and related medicines for treating diseases related to the colon, such as colorectal cancer and irritable bowel syndrome.

Morin Hydrate Encapsulation and Release from Mesoporous Silica Nanoparticles for Melanoma Therapy

Melanoma incidence, a type of skin cancer, has been increasing worldwide. There is a strong need to develop new therapeutic strategies to improve melanoma treatment. Morin is a bioflavonoid with the potential for use in the treatment of cancer, including melanoma. However, therapeutic applications of morin are restrained owing to its low aqueous solubility and limited bioavailability. This work investigates morin hydrate (MH) encapsulation in mesoporous silica nanoparticles (MSNs) to enhance morin bioavailability and consequently increase the antitumor effects in melanoma cells. Spheroidal MSNs with a mean size of 56.3 ± 6.5 nm and a specific surface area of 816 m²/g were synthesized. MH was successfully loaded (MH-MSN) using the evaporation method, with a loading capacity of 28.3% and loading efficiency of 99.1%. In vitro release studies showed that morin release from MH-MSNs was enhanced at pH 5.2, indicating increased flavonoid solubility. The in vitro cytotoxicity of MH and MH-MSNs on human A375, MNT-1 and SK-MEL-28 melanoma cell lines was investigated. Exposure to MSNs did not affect the cell viability of any of the cell lines tested, suggesting that the nanoparticles are biocompatible. The effect of MH and MH-MSNs on reducing cell viability was time- and concentration-dependent in all melanoma cell lines. The A375 and SK-MEL-28 cell lines were slightly more sensitive than MNT-1 cells in both the MH and MH-MSN treatments. Our findings suggest that MH-MSNs are a promising delivery system for the treatment of melanoma.

Nanoantioxidant Materials: Nanoengineering Inspired by Nature

Oxidants are very active compounds that can cause damage to biological systems under specific environmental conditions. One effective way to counterbalance these adverse effects is the use of anti-oxidants. At low concentrations, an antioxidant is defined as a compound that can delay, control, or prevent an oxidative process. Antioxidants exist in plants, soil, and minerals; therefore, nature is a rich source of natural antioxidants, such as tocopherols and polyphenols. In nature, antioxidants perform in tandem with their bio-environment, which may tune their activity and protect them from degradation. In vitro use of antioxidants, i.e., out of their biomatrix, may encounter several drawbacks, such as auto-oxidation and polymerization. Artificial nanoantioxidants can be developed via surface modification of a nanoparticle with an antioxidant that can be either natural or synthetic, directly mimicking a natural antioxidant system. In this direction, state-of-the-art nanotechnology has been extensively incorporated to overcome inherent drawbacks encountered in vitro use of antioxidants, i.e., out of their biomatrix, and facilitate the production and use of antioxidants on a larger scale. Biomimetic nanoengineering has been adopted to optimize bio-medical antioxidant systems to improve stability, control release, enhance targeted administration, and overcome toxicity and biocompatibility issues. Focusing on biotechnological sciences, this review highlights the importance of nanoengineering in developing effective antioxidant structures and comparing the effectiveness of different nanoengineering methods. Additionally, this study gathers and clarifies the different antioxidant mechanisms reported in the literature and provides a clear picture of the existing evaluation methods, which can provide vital insights into bio-medical applications.

Quercetin-Loaded Mesoporous Silica Nanoparticle-Based Lyophilized Tablets for Enhanced Physicochemical Features and Dissolution Rate: Formulation, Optimization, and In Vitro Evaluation

Mesoporous silica nanoparticles (MSNPs) have been proposed as a potential approach for stabilizing the amorphous state of poorly water-soluble actives. This study aimed to improve the physiochemical characteristics of poorly water-soluble quercetin (QT) through a novel lyophilized formulation. Various parameters, including solvent polarity, QT-carrier mass ratio, and adsorption time, were studied to improve the loading of QT into MSNPs. The optimized loaded MSNPs were formulated into lyophilized tablets through a freeze-drying process using hydrophilic polyvinylpyrrolidone (PVP-K30) as a polymeric stabilizer and water-soluble sucrose as a cryoprotectant. The effect of PVP-K30 and sucrose on the particle size, disintegration time, friability, and time required to release 90% of QT were studied using 3² full factorial design. The optimized formula was characterized using different evaluating techniques; for instance, differential scanning calorimetry, X-ray diffractometry, Fourier transform infrared spectroscopy, drug content, moisture content, and saturation solubility. The analysis proved that QT was consistently kept in the nanosize range with a narrow size distribution. The loaded silica nanoparticles and the optimized formulation are in an amorphous state devoid of any chemical interaction with the silica matrix or the lyophilization excipients. The optimized formula also featured low friability (less than 1%), fast disintegration (< 30 s), and a pronounced enhancement in saturation solubility and dissolution rate. Briefly, we established that the lyophilized MSNPs-based tablet would be a potential strategy for improving the rate of dissolution and, ultimately, the bioavailability of the poorly water-soluble QT.

Shape Memory Polymer Foams with Phenolic Acid-Based Antioxidant Properties

Phenolic acids (PAs) are natural antioxidant agents in the plant kingdom that are part of the human diet. The introduction of naturally occurring PAs into the network of synthetic shape memory polymer (SMP) polyurethane (PU) foams during foam fabrication can impart antioxidant properties to the resulting scaffolds. In previous work, PA-containing SMP foams were synthesized to provide materials that retained the desirable shape memory properties of SMP PU foams with additional antimicrobial properties that were derived from PAs. Here, we explore the impact of PA incorporation on SMP foam antioxidant properties. We investigated the antioxidant effects of PA-containing SMP foams in terms of in vitro oxidative degradation resistance and cellular antioxidant activity. The PA foams showed surprising variability; p-coumaric acid (PCA)-based SMP foams exhibited the most potent antioxidant properties in terms of slowing oxidative degradation in H₂O₂. However, PCA foams did not effectively reduce reactive oxygen species (ROS) in short-term cellular assays. Vanillic acid (VA)- and ferulic acid (FA)-based SMP foams slowed oxidative degradation in H₂O₂ to lesser extents than the PCA foams, but they demonstrated higher capabilities for scavenging ROS to alter cellular activity. All PA foams exhibited a continuous release of PAs over two weeks. Based on these results, we hypothesize that PAs must be released from SMP foams to provide adequate antioxidant properties; slower release may enable higher resistance to long-term oxidative degradation, and faster release may result in higher cellular antioxidant effects. Overall, PCA, VA, and FA foams provide a new tool for tuning oxidative degradation rates and extending potential foam lifetime in the wound. VA and FA foams induced cellular antioxidant activity that could help promote wound healing by scavenging ROS and protecting cells. This work could contribute a wound dressing material that safely releases antimicrobial and antioxidant PAs into the wound at a continuous rate to ideally improve healing outcomes. Furthermore, this methodology could be applied to other oxidatively degradable biomaterial systems to enhance control over degradation rates and to provide multifunctional scaffolds for healing.

Review on Nanoparticles and Nanostructured Materials: Bioimaging, Biosensing, Drug Delivery, Tissue Engineering, Antimicrobial, and Agro-Food Applications

In the last few decades, the vast potential of nanomaterials for biomedical and healthcare applications has been extensively investigated. Several case studies demonstrated that nanomaterials can offer solutions to the current challenges of raw materials in the biomedical and healthcare fields. This review describes the different nanoparticles and nanostructured material synthesis approaches and presents some emerging biomedical, healthcare, and agro-food applications. This review focuses on various nanomaterial types (e.g., spherical, nanorods, nanotubes, nanosheets, nanofibers, core-shell, and mesoporous) that can be synthesized from different raw materials and their emerging applications in bioimaging, biosensing, drug delivery, tissue engineering, antimicrobial, and agro-foods. Depending on their morphology (e.g., size, aspect ratio, geometry, porosity), nanomaterials can be used as formulation modifiers, moisturizers, nanofillers, additives, membranes, and films. As toxicological assessment depends on sizes and morphologies, stringent regulation is needed from the testing of efficient nanomaterials dosages. The challenges and perspectives for an industrial breakthrough of nanomaterials are related to the optimization of production and processing conditions.

Mesoporous silica nanoparticles-based formulations of a chimeric proteinous vaccine candidate against necrotic enteritis disease

To develop a nanoparticle-based vaccine against necrotic enteritis, a chimeric antigen (rNA) consisting of the main antigens of Clostridium perfringens, NetB, and Alpha toxin, was prepared. Then, the rNA molecules were loaded onto the functionalized mesoporous silica nanoparticles (MSNPs) using physical adsorption or covalent conjugation methods. The characterization of synthesized nanoparticles was performed by scanning electron microscopy, dynamic light scattering, zeta potential measurement, Fourier transform infrared spectroscopy, and thermogravimetry techniques. The results revealed that the spherical nanoparticles with an average diameter of 90 ± 12 nm and suitable surface chemistries are prepared. MSNPs-based formulations did not show any significant toxicity on the chicken embryo fibroblast cells. The results of the challenge experiments using subcutaneous or oral administration of the as-prepared formulations in the animal model showed that the as-prepared nanosystems, similar to those formulated with a commercial adjuvant (Montanide), present stronger humoral immune responses as compared to that of the free proteins. It was also indicated that the best protection is obtained in groups vaccinated with MSNPs-based nanovaccine, especially those who orally received covalently conjugated nanovaccine candidates. These results recommend that the MSNPs-based formulated chimeric proteinous vaccine candidates can be considered as an effective immunizing system for the oral vaccination of poultry against gastrointestinal infectious diseases.

Morin as an imminent functional food ingredient: an update on its enhanced efficacy in the treatment and prevention of metabolic syndromes

Flavonoids represent polyphenolic plant secondary metabolites with a general structure of a 15-carbon skeleton comprising two phenyl rings and a heterocyclic ring. Over 5000 natural flavonoids (flavanones, flavanonols, and flavans) from various plants have been characterized. Several studies provide novel and promising insights into morin hydrate for its different biological activities against a series of metabolic syndromes. The present review is a rendition of its sources, chemistry, functional potency, and protective effects on metabolic syndromes ranging from cancer to brain injury. Most importantly this systematic review article also highlights the mechanisms of interest to morin-mediated management of metabolic disorders. The key mechanisms (anti-oxidative and anti-inflammatory) responsible for its therapeutic potential are well featured after collating the in vitro and in vivo study reports. As a whole, based on the prevailing information rationalizing its medicinal use, morin can be identified as a therapeutic agent for the expansion of human health.

Polyoxometalate-Mediated Vacancy-Engineered Cerium Oxide Nanoparticles Exhibiting Controlled Biological Enzyme-Mimicking Activities

The biological enzyme-mimetic activity of cerium oxide nanoparticles (CeNPs) is well known to scavenge the reactive oxygen and nitrogen species in cell culture and animal models, imparting protection from the deleterious effects of oxidative and nitrosative stress. The superoxide dismutase (SOD)- and catalase-mimicking activity of CeNPs is reported to be controlled by the oxidation state of the surface "Ce" ions, where a high ratio of Ce^3+/4+ or Ce^4+/3+ has been considered for the displayed SOD and catalase-like activity, respectively. However, the redox behavior of CeNPs can be controlled by certain ligands that could offer changes in their enzyme-mimetic properties. Therefore, in this work, we have studied the enzyme-mimetic activities of CeNPs under the influence of polyoxometalates [phosphomolybdic acid (PMA) and phosphotungstic acid (PTA)], which are electron-dense molecules displaying quick and reversible multielectron redox reactions. Results revealed that the interaction of PMA with CeNPs results in the inhibition of the SOD-like activity; however, it has no impact on the catalase-like activity. Contrary to this, the interaction of PTA with CeNPs improved the SOD as well as catalase-like activities of CeNPs (3+), which generally do not exhibit catalase activity in the bare form. Although CeNPs (3+) did not show any peroxidase-like activity, CeNPs (4+) showed excellent activity, which was enhanced after the interaction with polyoxometalates. Further, the autoregeneration ability of CeNPs was found to be intact even after PTA or PMA interaction; however, the full catalytic activity was observed in the case of PTA but partially with PMA.

Investigation on the Linear and Nonlinear Properties of Morin in Presence of Reverse Micelle and Different Oil Content in Reverse Micelle

We investigate the linear and nonlinear optical property of Morin (MN) at different concentration (1 × 10-6 and 5 × 10-6 M) within AOT reversed micelle prepared by water-in-decane microemulsion having a constant molar ratio of water-to-surfactant molecules of 40 (W = [H2O]/[AOT] = 40) as well as the function of mass fraction of nano-droplet (MFD) values of 0.01,0.04, 0.07, and 0.1 by using UV-Visible, Fluorescence, FTIR, and Z-scan techniques. The steady-state measurement indicates that the presence of microenvironment can greatly affect the tautomeric structure of morin and also Morin property in microenvironment depends upon the amount of oil and Morin concentration. The increase in dipole moment from the ground state to excited state in microenvironment indicate the change in the molecular structure on morin. Morin does not show any nonlinear absorption property but the nonlinear refractive index is observed as a function of Morin concentration as well as MFD values which are due to the thermal agitation of formed dimers. Morin nonlinearity.

Optimization of debittering and deacidification parameters for Pomelo juice and assessment of juice quality

Bitterness and tartness are one of the crucial reasons for the poor commerciality of Pomelo fruits. The present study intends to optimize the process variables such as resin concentration (Amberlite IRA-400) (3-10 g), time exposure (10-60 s), and stirring speed (300-1000 rpm) for removal of naringin content and tartness using response surface methodology. All the independent variables have shown a significant effect on naringin content, titrable acidity, and vitamin C content of pomelo juice. The optimized process variables for debittering and deacidification were 3.27 g resin concentration, 60 s time and 1000 rpm stirring speed, and the naringin content and titrable acidity at these optimized conditions were 0.22 mg ml^-1 and 0.64% citric acid equivalent respectively. The treated juice under optimum conditions was analyzed for physicochemical properties where pH, clarity, and L* value of juice increased. In contrast, total soluble solids, vitamin C content, and a* value decreased slightly. The finding of present investigation will be helpful to improve the commercial acceptability of the sour variety of citrus fruit juice.

Carminic Acid Linked to Silica Nanoparticles as Pigment/Antioxidant Bifunctional Excipient for Pharmaceutical Emulsions

The incorporation of pigments and natural polyphenols into inorganic matrices, resulting in a hybrid material that improves the resistance and chemical stability of the pigments and the antioxidant capacity of the materials, has been of great interest to the pharmaceutical, chemical and food industries. The aim of this work was to prepare and characterize a bifunctional pigment-antioxidant nanomaterial-based carminic acid-decorated solid core-mesoporous shell silica nanoparticles, evaluating its properties as a pigment, its antioxidant capacity and its properties as a chemical stabilizer of emulsions. The chemical stability of oil-in-water (O/W) Pickering emulsions was evaluated determining the stability of vitamin E solubilized in the oil phase. Carminic acid was attached through the action of coupling ethylcarbodiimide hydrochloride (EDC)/N-hydroxysuccinimide (NHS) agents, and the resulting spherical and homogeneous nanoparticles showed a diameter close to 175 nm. A notorious change of emulsion color was observed by the addition of the nanomaterial. Emulsions showed an attractive pink color, and when the pH was adjusted to pH 3 and pH 9, a change in color was observed, analogous to carminic acid in solution. The nanomaterial incorporation also improved chemical stability, decreasing vitamin E consumption to 9.26% of the initial value, demonstrating an important antioxidant effect of the developed nanomaterial.

Nanoantioxidant-Based Silica Particles as Flavonoid Carrier for Drug Delivery Applications

Nanosystems used in pharmaceutical formulations have shown promising results in enhancing the administration of drugs of difficult formulations. In particular, porous silica nanoparticles have demonstrated excellent properties for application in biological systems; however, there are still several challenges related to the development of more effective and biocompatible materials. An interesting approach to enhance these nanomaterials has been the development of nanoantioxidant carriers. In this work, a hybrid nanoantioxidant carrier based on porous silica nanoplatform with rosmarinic acid antioxidant immobilized on its surface were developed and characterized. Techniques such as dynamic light scattering (DLS), zeta potential, transmission electron microscopy (TEM), N2 adsorption-desorption measurements, differential scanning calorimetry (DSC), Fourier transform-infrared spectroscopy (FT-IR), and 2,2-diphenyl-1-picrylhydrazyl (DPPH●) assay were used to characterize and evaluate the antioxidant activity of nanocarriers. In addition, drug release profile was evaluated using two biorelevant media. The antioxidant activity of rosmarinic acid was maintained, suggesting the correct disposition of the moiety. Kinetic studies reveal that more morin is released in the simulated intestinal fluid than in the gastric one, while an anomalous non-Fickian release mechanism was observed. These results suggest a promising antioxidant nanocarrier suitable for future application in drug delivery.

Nanoantioxidants: Recent Trends in Antioxidant Delivery Applications

Antioxidants interact with free radicals, terminating the adverse chain reactions and converting them to harmless products. Antioxidants thus minimize the oxidative stress and play a crucial role in the treatment of free radicals-induced diseases. However, the effectiveness of natural and/or synthetic antioxidants is limited due to their poor absorption, difficulties to cross the cell membranes, and degradation during delivery, hence contributing to their limited bioavailability. To address these issues, antioxidants covalently linked with nanoparticles, entrapped in nanogel, hollow particles, or encapsulated into nanoparticles of diverse origin have been used to provide better stability, gradual and sustained release, biocompatibility, and targeted delivery of the antioxidants with superior antioxidant profiles. This review aims to critically evaluate the recent scientific evaluations of nanoparticles as the antioxidant delivery vehicles, as well as their contribution in efficient and enhanced antioxidant activities.

Synergistically dual-functional nano eye-drops for simultaneous anti-inflammatory and anti-oxidative treatment of dry eye disease

We have developed a rapid and straightforward topical treatment method for dry eye disease (DED) using poly(catechin) capped-gold nanoparticles (Au@Poly-CH NPs) carrying amfenac [AF; a nonsteroidal anti-inflammatory drug (NSAID)] through effective attenuation of ocular surface tissue damage in dry eyes. A dual-targeted strategy based on ocular therapeutics was adopted to simultaneously block the cyclooxygenase enzymes-induced inflammation and reactive oxygen species (ROS)-induced oxidative stress, the primary two causes of DED. The self-assembled core-shell Au@Poly-CH NPs synthesized via a simple reaction between tetrachloroaurate(iii) and catechin possess a poly(catechin) shell (∼20 nm) on the surface of each Au NP (∼60 nm). The anti-oxidant and anti-inflammatory properties of AF/Au@Poly-CH NPs were evaluated by DCFH-DA and prostaglandin E2/VEGF assays, respectively. Our results demonstrate that Au@Poly-CH NPs not only act as an anti-oxidant to suppress ROS-mediated processes, but also serve as a drug carrier of AF for a synergistic effect on anti-inflammation. In vivo biocompatibility studies show good tolerability of AF/Au@Poly-CH NPs for potential use in the treatment of ocular surface pathologies. The dual-targeted therapeutic effects of AF/Au@Poly-CH NPs lead to rapid recovery from DED in a rabbit model. Au@Poly-CH NPs loaded with NSAIDs is a promising multifunctional nanocomposite for treating various inflammation- and oxidative stress-related diseases.

Antioxidant Nanomaterial Based on Core⁻Shell Silica Nanospheres with Surface-Bound Caffeic Acid: A Promising Vehicle for Oxidation-Sensitive Drugs

The design of efficient, biocompatible, and easily prepared vehicles for drug delivery is a subject of great interest for medicine and pharmaceutical sciences. To achieve the above goals, surface functionalization is critical. Here, we report a hybrid nanocarrier consisting of core⁻shell silica nanospheres and the antioxidant caffeic acid linked to the surface, to evaluate their in vitro antioxidant capacity, their capability to protect oxidation-sensitive compounds incorporated in nanoparticles, and to study the interaction with bovine serum albumin protein. The results show that the radical-scavenging activity of immobilized caffeic acid is attenuated in the silica nanospheres; however, other antioxidant properties such as Fe2+-chelating activity and singlet oxygen quenching are enhanced. In addition, caffeic acid is protected from binding to proteins by the nanoparticle, suggesting that this nanosystem is more likely to maintain the antioxidant activity of caffeic acid in biological media. Finally, the natural antioxidant barrier on the nanocarrier is able to delay the degradation of a compound incorporated into this nanovehicle. Considering all findings, this work proposes a suitable tool for pharmaceutical and cosmetic industries as an antioxidant nanocarrier for oxidation-sensitive drugs.

Mechanisms of DNA damage induced by morin, an inhibitor of amyloid β-peptide aggregation

Morin is a potential inhibitor of amyloid β-peptide aggregation. This aggregation is involved in the pathogenesis of Alzheimer's disease. Meanwhile, morin has been found to be mutagenic and exhibits peroxidation of membrane lipids concurrent with DNA strand breaks in the presence of metal ions. To clarify a molecular mechanism of morin-induced DNA damage, we examined the DNA damage and its site specificity on ³²P-5'-end-labeled human DNA fragments treated with morin plus Cu(II). The formation of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG), an indicator of oxidative DNA damage, was also determined in calf thymus DNA treated with morin plus Cu(II). Morin-induced DNA strand breaks and base modification in the presence of Cu(II) were dose dependent. Morin plus Cu(II) caused piperidine-labile lesions preferentially at thymine and guanine residues. The DNA damage was inhibited by methional, catalase and Cu(I)-chelator bathocuproine. The typical •OH scavengers ethanol, mannitol and sodium formate showed no inhibitory effect on DNA damage induced by morin plus Cu(II). When superoxide dismutase was added to the solution, DNA damage was not inhibited. In addition, morin plus Cu(II) increased 8-oxodG formation in calf thymus DNA fragments. We conclude that morin undergoes autoxidation in the presence of Cu(II) via a Cu(I)/Cu(II) redox cycle and H₂O₂ generation to produce Cu(I)-hydroperoxide, which causes oxidative DNA damage.

Designing of fatty acid-surfactant conjugate based nanomicelles of morin hydrate for simultaneously enhancing anticancer activity and oral bioavailability

Morin hydrate (MH) is a naturally occurring polyphenolic flavonol compound. It has been recently investigated for its many biological activities such as anti-inflammatory, anticancer, antioxidant, antiarthritic, antifertility, antiplasmodic and anticancer. Though these outcomes are very promising, its low aqueous solubility and oral bioavailability restrict its clinical uses. Therefore, in this study we report pluronic F68 and stearic acid conjugated (F68-SA) nanomicelles for increasing oral bioavailability of MH. The MH loaded F68-SA nanomicelles (MHNM) were prepared by the solvent evaporation method. The MHNM were extensively characterized for the size, surface charge, stability, morphology, critical micelle concentration, drug content, and in-vitro drug release. The cell viability assay depicted a significant increase in cytotoxicity of MH against A549 human lung cancer cells after incubating as MHNM. Exposure of A549 cells to MHNM induced cell apoptosis in the cells as observed in apoptosis studies. Pharmacokinetic studies in Sprague-Dawley rats revealed that MHNM significantly increased the oral bioavailability of MH as compared to pure drug. Therefore, the novel, surfactant-lipid based micellar system is an effective solubilizing and delivering system for oral administration of poorly water soluble drugs like MH.

Gel-Mediated Electrospray Assembly of Silica Supraparticles for Sustained Drug Delivery

Supraparticles (SPs) composed of smaller colloidal particles provide a platform for the long-term, controlled release of therapeutics in biomedical applications. However, current synthesis methods used to achieve high drug loading and those involving biocompatible materials are often tedious and low throughput, thereby limiting the translation of SPs to diverse applications. Herein, we present a simple, effective, and automatable alginate-mediated electrospray technique for the assembly of robust spherical silica SPs (Si-SPs) for long-term (>4 months) drug delivery. The Si-SPs are composed of either porous or nonporous primary Si particles within a decomposable alginate matrix. The size and shape of the Si-SPs can be tailored by controlling the concentrations of alginate and silica primary particles used and key electrospraying parameters, such as flow rate, voltage, and collector distance. Furthermore, the performance (including drug loading kinetics, loading capacity, loading efficiency, and drug release) of the Si-SPs can be tuned by changing the porosity of the primary particles and through the retention or removal (via calcination) of the alginate matrix. The structure and morphology of the Si-SPs were characterized by electron microscopy, dynamic light scattering, N₂ adsorption-desorption analysis, and X-ray photoelectron spectroscopy. The cytotoxicity and degradability of the Si-SPs were also examined. Drug loading kinetics and loading capacity for six different types of Si-SPs, using a model protein drug (fluorescently labeled lysozyme), demonstrate that Si-SPs prepared from primary silica particles with large pores can load significant amounts of lysozyme (∼10 μg per SP) and exhibit sustained, long-term release of more than 150 days. Our experiments show that Si-SPs can be produced through a gel-mediated electrospray technique that is robust and automatable (important for clinical translation and commercialization) and that they present a promising platform for long-term drug delivery.

Mesoporous Silica Nanoparticles: A Comprehensive Review on Synthesis and Recent Advances

Recent advancements in drug delivery technologies utilizing a variety of carriers have resulted in a path-breaking revolution in the approach towards diagnosis and therapy alike in the current times. Need for materials with high thermal, chemical and mechanical properties have led to the development of mesoporous silica nanoparticles (MSNs). These ordered porous materials have garnered immense attention as drug carriers owing to their distinctive features over the others. They can be synthesized using a relatively simple process, thus making it cost effective. Moreover, by controlling the parameters during the synthesis; the morphology, pore size and volume and particle size can be transformed accordingly. Over the last few years, a rapid increase in research on MSNs as drug carriers for the treatment of various diseases has been observed indicating its potential benefits in drug delivery. Their widespread application for the loading of small molecules as well as macromolecules such as proteins, siRNA and so forth, has made it a versatile carrier. In the recent times, researchers have sorted to several modifications in the framework of MSNs to explore its potential in drug resistant chemotherapy, antimicrobial therapy. In this review, we have discussed the synthesis of these multitalented nanoparticles and the factors influencing the size and morphology of this wonder carrier. The second part of this review emphasizes on the applications and the advances made in the MSNs to broaden the spectrum of its use especially in the field of biomedicine. We have also touched upon the lacunae in the thorough understanding of its interaction with a biological system which poses a major hurdle in the passage of this carrier to the clinical level. In the final part of this review, we have discussed some of the major patents filed in the field of MSNs for therapeutic purpose.

Catechin-conjugated mesoporous hydroxyapatite nanoparticle: A novel nano-antioxidant with enhanced osteogenic property

Hydroxyapatite is the main component of mineral phase of bone which is widely employed for coating metal implants and scaffold materials in synthetic bone grafts owing to its osteoinductive property. In order to improve the bioactivity of hydroxyapatite, mesoporous hydroxyapatite nanoparticles (MHAP) were synthesized and chemically functionalized with 3-aminopropyltriethoxysilane. The amine-functionalized nanoparticles were conjugated with a natural antioxidant, catechin (Cat), through a stable amide linkage. The true structure of the bioconstruct was confirmed by calculating condensed Fukui indices. The functionalized-hydroxyapatite nanoparticles (Cat@MHAP) showed an outstanding antioxidant activity, having reactivity toward hydroxyl and superoxide radicals larger than that of free catechin. To explore the bone cell responses to this material, multilayer nanoparticle films were prepared by MHAP and Cat@MHAP on a glass substrate. Afterward, the short- and long-term responses of cultured mesenchymal stem cells (MSCs), osteosarcoma cells (Saos-2), and doxorubicin-resistant cells (RSaos-2/Dox) on the surface of the prepared films were investigated. Both the MSCs and bone tumor cells selectively adhered onto Cat@MHAP surface as compared with glass and MHAP at initial culture time. Moreover, it was found that Cat@MHAP decreases the proliferation of Saos-2 and RSaos-2/Dox cells in a time-dependent manner, while it supports the growth of MSCs, indicating the ability of Cat@MHAP to distinguish tumor cells from normal ones. Further, Cat@MHAP promotes the osteogenic differentiation in both the MSCs and tumor cells, accompanied by the attenuation of intracellular ROS. From these results, Cat@MHAP is a novel "nano-antioxidant," which could be considered as a promising biomaterial in treating bone defects, particularly after surgery in osteosarcoma patients.

Adsorption and Recovery of Polyphenolic Flavonoids Using TiO2-Functionalized Mesoporous Silica Nanoparticles

Exploiting specific interactions with titania (TiO₂) has been proposed for the separation and recovery of a broad range of biomolecules and natural products, including therapeutic polyphenolic flavonoids which are susceptible to degradation, such as quercetin. Functionalizing mesoporous silica with TiO₂ has many potential advantages over bulk and mesoporous TiO₂ as an adsorbent for natural products, including robust synthetic approaches leading to high surface area, and stable separation platforms. Here, TiO₂-surface-functionalized mesoporous silica nanoparticles (MSNPs) are synthesized and characterized as a function of TiO₂ content (up to 636 mg TiO₂/g). The adsorption isotherms of two polyphenolic flavonoids, quercetin and rutin, were determined (0.05-10 mg/mL in ethanol), and a 100-fold increase in the adsorption capacity was observed relative to functionalized nonporous particles with similar TiO₂ surface coverage. An optimum extent of functionalization (approximately 440 mg TiO₂/g particles) is interpreted from characterization techniques including grazing incidence X-ray scattering (GIXS), high-resolution transmission electron microscopy (HRTEM), and nitrogen adsorption, which examined the interplay between the extent of TiO₂ functionalization and the accessibility of the porous structures. The recovery of flavonoids is demonstrated using ligand displacement in ethanolic citric acid solution (20% w/v), in which greater than 90% recovery can be achieved in a multistep extraction process. The radical scavenging activity (RSA) of the recovered and particle-bound quercetin as measured by a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay demonstrates greater than 80% retention of antioxidant activity by both particle-bound and recovered quercetin. These mesoporous titanosilicate materials can serve as a synthetic platform to isolate, recover, and potentially deliver degradation-sensitive natural products to biological systems.

Lyophilized aqueous extracts of Mori Fructus and Mori Ramulus protect Mesenchymal stem cells from •OH-treated damage: bioassay and antioxidant mechanism

Background

Mori Fructus and Mori Ramulus are two traditional Chinese herbal medicines from mulberries. The present work explores their beneficial effects on •OH–treated mesenchymal stem cells (MSCs) and discusses possible mechanisms.

Methods

Lyophilized aqueous extracts of Mori Fructus (LAMF) and Mori Ramulus (LAMR) were prepared and analyzed using HPLC. LAMF and LAMR (along with morin) were further investigated for their effects on •OH-treated MSCs using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl (MTT) assay. The direct antioxidation mechanisms were studied using 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO•)-scavenging, 2,2′-azino-bis (3-ethylbenzo-thiazoline-6-sulfonic acid (ABTS⁺•)-scavenging and 1,1-diphenyl-2-picryl-hydrazl (DPPH•)-scavenging, as well as Cu²⁺-reducing and Fe³⁺-reducing antioxidant power. Finally, the indirect antioxidant mechanism was investigated based on the UV-vis spectra of Fe²⁺-chelation.

Results

In each LAMF and LAMR, seven phytophenols were successfully measured by HPLC, including five flavonoids (morin, rutin, astragalin, isoquercitrin and luteolin) and two non-flavonoids (chlorogenic acid and maclurin). MTT assays revealed that LAMF, LAMR and morin could effectively increase the survival of •OH-treated MSCs at 10–100 μg/mL, and could effectively scavenge PTIO• (IC ₅₀ 6609.7 ± 756.6, 4286.9 ± 84.9 and 103.4 ± 0.9 μg/mL, respectively), DPPH• (IC ₅₀ 208.7 ± 3.0, 97.3 ± 3.1 and 8.2 ± 0.7 μg/mL, respectively) and ABTS⁺• (IC ₅₀ 73.5 ± 5.8, 34.4 ± 0.1 and 4.2 ± 0.2 μg/mL, respectively), and reduce Cu²⁺ (IC ₅₀ 212.5 ± 7.0, 123.2 ± 0.9 and 14.1 ± 0.04 μg/mL, respectively) & Fe³⁺ (IC ₅₀ 277.0 ± 3.1, 191.9 ± 5.2 and 5.0 ± 0.2 μg/mL, respectively). In the Fe²⁺-chelating assay, the five flavonoids produced much stronger shoulder-peaks than the two non-flavonoids within 420–850 nm.

Conclusion

Mori Fructus and Mori Ramulus, can protect MSCs from •OH-induced damage. Such beneficial effects can mainly be attributed to the antioxidant action of phytophenols, which occurs via direct (ROS-scavenging) and indirect mechanism (Fe²⁺-chelating). The ROS-scavenging mechanism, however, include at least a H⁺-transfer and an electron-transfer (ET), and possibly includes a hydrogen-atom-transfer (HAT). In the Fe²⁺-chelating, flavonoids are more effective than non-flavonoids. This can be attributed to several adjacent planar chelating-sites between the 3-OH and 4-C = O, between the 4-C = O and 5-OH, or between the 3′-OH and 4′-OH in flavonoids. Such multiple-Fe²⁺-chelating reactions cause overlap in the UV-vis absorptions to deepen the complex color, enhance the peak strength, and form shoulder-peaks. By comparison, two non-flavonoids with catechol moiety produce only a weak single peak.

Electronic supplementary material

The online version of this article (doi:10.1186/s12906-017-1730-3) contains supplementary material, which is available to authorized users.