Development and evaluation of PLGA polymer based nanoparticles of quercetin

Advancements in delivery systems for dietary polyphenols in enhancing radioprotection effects: challenges and opportunities

Radiotherapy, a widely employed cancer treatment, often triggers diverse inflammatory responses such as radiation enteritis, pulmonary injury, pelvic inflammation, dermatitis, and osteitis. Dietary polyphenols have recently emerged as promising agents for mitigating radiation-induced inflammation. However, their clinical application faced challenges related to variable bioavailability, individual pharmacokinetics, optimal dosing, and limited clinical evidence. Current researches revealed the efficacy of bioactive small molecule polyphenols in addressing radiation-induced inflammation. In this review, along with a comprehensive examination of the etiology and categories of radiation-induced inflammatory conditions, the diversity of polyphenols and elucidating their anti-inflammatory mechanisms are explored. This study emphasizes the recent progresses in delivery systems for dietary polyphenols, aiming to enhance radioprotection effects. The optimized utilization of polyphenols, with a theoretical framework and reference guide, is of paramount relevance. Through diverse delivery mechanisms, the more effective and safer radioprotective strategies become achievable. This endeavor aspires to contribute to breakthroughs in the dietary polyphenols' application, significantly enhancing human health protection during radiotherapy. These comprehensive insights presented here also support (pre)-clinical practices in navigating the complexities of utilizing dietary polyphenols for radioprotection, fostering advancements in the field and improving patient outcomes.

Targeting respiratory virus-induced reactive oxygen species in airways diseases

The immune response to virus infection in the respiratory tract must be carefully balanced to achieve pathogen clearance without excessive immunopathology. For chronic respiratory diseases where there is ongoing inflammation, such as in asthma and COPD, airway immune balance is perturbed, and viral infection frequently worsens (exacerbates) these conditions. Reactive oxygen species (ROS) are critical to the induction and propagation of inflammation, and when appropriately regulated, ROS are vital cell signalling molecules and contribute to innate immunity. However, extended periods of high ROS concentration can cause excessive cellular damage that dysregulates antiviral immunity and promotes inflammation. Traditional antioxidant therapeutics have had limited success treating inflammatory diseases such as viral exacerbations of asthma or COPD, owing to nonspecific pharmacology and poorly understood pharmacokinetic properties. These drawbacks could be addressed with novel drug delivery technologies and pharmacological agents. This review summarises current research on ROS imbalances during virus infection, discusses the commercially available mitochondrial antioxidant drugs that have progressed to clinical trial and assesses novel drug delivery approaches for antioxidant delivery to the airways. Additionally, it provides a perspective on future research into pharmacological targeting of ROS for the treatment of respiratory virus infection and disease.

Development of barley proteins into peptides nanomicelles for encapsulation of hydrophobic bioactive ingredient

BACKGROUND

As natural polymer materials, barley proteins have been utilized to fabricate nanocarriers to encapsulate and delivery hydrophobic bioactive ingredients. However, as a result of the high proportion of hydrophobic amino acids and structural rigidity, barley protein-based nanocarriers tend to aggregate easily and have a low loading capacity, which greatly limits their application. In the present study, barley proteins were enzymolyzed to fabricate nanomicelles and then applied to encapsulate hydrophobic bioactive ingredient.

RESULTS

Self-assembled barley peptides could be obtained by controllable enzymolysis of barley proteins. The obtained barley peptides could self-assemble into nanomicelles (BPNMs) with a diameter of approximately 90 nm when the concentration was > 2.1 μg mL-1. Hydrophobic interaction, disulfide bonds and hydrogen bonds were involved in maintaining the structure of BPNMs. Six self-assembled peptides (QQPFPQ, QTPLPQ, QLPQIPE, QPFPQQPQLPH, QPFPQQPPFGL and QPFPQQPPFWQQQ) were identified and they were characterized by alternating arrangement of hydrophobic amino acids and hydrophilic amino acids. Moreover, BPNMs were utilized to encapsulate hydrophobic bioactive ingredient quercetin. When quercetin was encapsulated by BPNMs, its water solubility was significantly increased, being approximately 30-fold higher than free quercetin. Meanwhile, encapsulation of BPNMs could greatly increase quercetin stability. The interaction between BPNMs and quercetin occurred spontaneously, mainly driven by van der Waals forces and hydrogen bonds.

CONCLUSION

In the present study, BPNMs were successfully developed and could be used as a promising delivery system to improve the water solubility and stability of hydrophobic bioactive ingredients. © 2024 Society of Chemical Industry.

Chitosan-modified polymeric nanoparticles for the nose-to-brain drug delivery of paroxetine: an in vitro and in vivo evaluation

This work focuses on the development of PLGA nanoparticles and their surface modification by chitosan to enhance the mucoadhesive properties and colloidal stability for intranasal delivery. Chitosan-coated paroxetine-loaded PLGA nanoparticles (PAR-CS-PLGA-NPs) were developed and characterized along with in vitro and in vivo evaluation. Particle size of 181.8 nm with a zeta potential of 36.3 mV was obtained. Entrapment efficiency % and drug loading % were 87.5% and 13.4%, respectively. TEM, FTIR, and DSC were also performed. In vitro drug release studies were conducted in phosphate buffered saline (pH 7.4) and simulated nasal fluid (pH 5.5), and sustained release was found until 72 h. Cellular assays on mammalian cells depicted the cell viability to be >60% even at the maximum concentration of PAR-CS-PLGA-NPs and showed significantly higher uptake than PLGA-NPs. Histopathological studies on the nasal epithelium showed no damage or inflammation when treated with PAR-CS-PLGA-NPs. In vivo studies were performed using Swiss albino mice to estimate the drug biodistribution after intranasal delivery of PAR-CS-PLGA-NPs. A significantly increased drug concentration was observed in the mouse brains (p < 0.05). Pharmacodynamics studies of the PAR-CS-PLGA-NPs were carried out by forced swimming test and locomotor activity test, demonstrating improved behavioral analysis parameters (p < 0.05). Thus, intranasal delivery of paroxetine-loaded mucoadhesive chitosan-coated PLGA nanoparticles could be potentially used for the treatment of depression.

Intensification of quercetin nanobubble formulation and performance by multi-factor optimization and interaction analysis

The natural flavonoid Quercetin (QT) showed a potential for various health benefits, but its pharmaceutical applications are hindered by low solubility, permeability, and limited bioavailability. This research aimed to synthesize, develop and optimize polylactic acid co-glycolic acid (PLGA) nanobubbles using solvent evaporation method as a sustained delivery system for QT, thus improving stability and bioavailability. Through a four-factor, three-level Box Behnken Design, 29 experimental runs were carried out to optimize QT-PLGA nanobubbles. An optimized formulation consisted of 50 mg QT, 250 mg PLGA, and 1.89% w/v PVA. The nanobubbles displayed a particle size of 139.5 ± 6.24 nm, polydispersity index of 0.296 ± 0.19, and zeta potential of -23.0 ± 3.44 mV, with an entrapment efficiency of 59.24 ± 3.08%. Analysis through Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction confirmed no drug-polymer interaction, while scanning electron microscopy revealed a uniform spherical nanoparticle. In vitro studies exhibited an excellent drug release, and stability studies showed no significant changes after one month. In vivo studies in rats demonstrated increased Cmax (3.03) and AUC0-t (5.84), indicating an improved sustained release and absorption. These findings underscored a potential of QT-loaded PLGA nanobubbles to enhance the drug kinetics and bioavailability, offering possibilities for targeted drug delivery and improved therapeutic outcomes.

Fabrication and Characterization of Agar- and Seaweed-Derived Biomembrane Films for Biomedical and Other Applications

This study focused on seaweed-based biomembrane development. The physical, mechanical, thermal, and biological properties of the fabricated films with different combinations of materials, such as agar, chitosan, poly(vinyl) alcohol (PVA), and quercetin, were characterized. The surface morphology of the films was analyzed using SEM. The maximum tensile strength (53.11 N/mm2), elongation at break (3.42%), and Young's modulus (15.52) of the biomembrane were recorded for the agar + chitosan combination. FT-Raman analysis confirmed the functional groups shift between the biopolymer and plasticizer used in this study. TG-DSC analysis of the biomembranes revealed a Tg in the range of 92.80°C-115°C. The maximum antioxidant activity was reported for quercetin (58.62%), and the maximum antimicrobial activity was observed for the chitosan and quercetin compounds against E. coli. A minimum hemolysis of 0.95% was achieved for the combination of agar + quercetin (AQ), agar + PEG (APE), Gracilaria corticata extract + PVA + quercetin (GCPQ) and agar + chitosan (AC) biomembranes. The minimum cytotoxicity of the biomembrane was 62.51% and 63.87% for Gracilaria corticata extract + PVA + quercetin (GCPQ), and agar + PVA, respectively. The proposed biomembrane films were found to be suitable for biomedical and packaging applications.

Silk fibroin/chitosan thiourea hydrogel scaffold with vancomycin and quercetin-loaded PLGA nanoparticles for treating chronic MRSA osteomyelitis in rats

Chronic osteomyelitis presents significant treatment challenges, necessitating an efficient system for infection elimination and bone repair. This study developed a natural hydrogel scaffold using silk fibroin (SF) and chitosan thiourea (CST), incorporating vancomycin (VC) and quercetin (QC) loaded PLGA nanoparticles (NPs) for dual-purpose treatment. SF/CST hydrogel scaffolds exhibited homogeneous porosity and smaller interconnected pore size than pure SF and pure CST hydrogel scaffolds. Optimal PLGA/QC NPs measured 206 nm in size, displayed spherical morphology, had uniform distribution, and achieved 87 % QC loading. The release study showed sustained long-term release of VC and QC from the hydrogel scaffolds for over 20 days. Biocompatibility tests indicated that hydrogel scaffolds promoted osteoblast adhesion without cytotoxicity, with QC-containing scaffolds enhancing osteoblast growth. Antibacterial tests confirmed retained VC activity against methicillin-resistant Staphylococcus aureus (MRSA) in SF/CST. An experimental study assessed the efficacy of the hydrogel scaffolds in a MRSA-infected rat osteomyelitis model. Radiographic scores demonstrated a significant reduction for SF/CST-VC-PLGA/QC NPs compared to control, indicating reduced osteomyelitis effects. Macroscopic evaluations showed notable reductions in gross pathological effects for VC-containing groups. Histopathological assessments revealed significantly lower osteomyelitis scores and higher healing scores in the SF/CST-VC-PLGA/QC NPs, with reduced inflammatory cell infiltration and more organized connective tissue formation. In conclusion, SF/CST-VC-PLGA/QC NPs is an effective dual drug delivery system for osteomyelitis treatment, demonstrating significant antibacterial activity, enhanced bone regeneration, and reduced infection rate.

Quercetin/Polyethyleneimine Modified Gold Nanoconjugates Inhibit Apoptosis and ROS Production Induced by Hydrogen Peroxide in DRG Sensory Neurons

The basis of most neurological syndromes is the accumulation of free radical molecules. Quercetin is a polyphenolic bioflavonoid molecule and it has a very strong antioxidant effect by maintaining oxidative balance. There are many difficulties in the clinical use of quercetin due to its hydrophobic structure, low solubility, instability, poor oral bioavailability, and limited tissue-barrier penetration. Its synergistic use in complex with gold nanoparticles (AuNPs) could overcome these problems. AuNPs have recently emerged as an attractive candidate for delivery applications of various biomolecules and drugs. The aim of this study was to synthesize two different sized gold nanoparticles (AuNP20 and AuNP50) modified with polyethyleneimine (PEI) and quercetin, evaluate their potential neuroprotective effects on the in vitro oxidative stress model using DRG primary sensory neurons. It was shown that the antioxidant and anti-apoptotic ability of the bioflavonoid was preserved after exposure to the designed quercetin modified AuNPs. The PEI surface coating increased the stability and biocompatibility of the AuNPs in both sizes. It also potentially enables additional surface functionalization. This study indicates that designed nanoparticles (AuNP-Q-PEI) with different sizes could be a useful potential platform for the treatment of neurodegenerative syndromes or cancer diseases.

Optimization of Polylactide-Co-Glycolide-Rifampicin Nanoparticle Synthesis, In Vitro Study of Mucoadhesion and Drug Release

Despite the large number of works on the synthesis of polylactide-co-glycolide (PLGA) nanoparticles (NP) loaded with antituberculosis drugs, the data on the influence of various factors on the final characteristics of the complexes are quite contradictory. In the present study, a comprehensive analysis of the effect of multiple factors, including the molecular weight of PLGA, on the size and stability of nanoparticles, as well as the loading efficiency and release of the antituberculosis drug rifampicin (RIF), was carried out. Emulsification was carried out using different surfactants (polyvinyl alcohol, Tween 80 and Pluronic F127), different aqueous-to-organic phase ratios, and different solvents (dichloromethane, dimethyl sulfoxide, ethyl acetate). In this research, the PLGA nanoemulsion formation process was accompanied by ultrasonic dispersion, at different frequencies and durations of homogenization. The use of the central composite design method made it possible to select optimal conditions for the preparation of PLGA-RIF NPs (particle size 223 ± 2 nm, loading efficiency 67 ± 1%, nanoparticles yield 47 ± 2%). The release of rifampicin from PLGA NPs was studied for the first time using the flow cell method and vertical diffusion method on Franz cells at different pH levels, simulating the gastrointestinal tract. For the purpose of the possible inhalation administration of rifampicin immobilized in PLGA NPs, their mucoadhesion to mucin was studied, and a high degree of adhesion of polymeric nanoparticles to the mucosa was shown (more than 40% within 4 h). In the example of strain H37Rv in vitro, the sensitivity of Mycobacterium tuberculosis to PLGA-RIF NPs was proven by the complete inhibition of their growth.

Method development and validation for the quantitative determination of total flavonoids through the complexation of iron (III) and its application in real sample

BACKGROUND

The determination of flavonoids in real sample using UV-Vis spectrophotometer commonly uses quercetin and catechin with Al+3 complexing agent as reference materials for the calibration of the instrument. However, getting these standard materials is challenging due to its expense and unavailability in the chemical reserve of the country. Moreover, the Al+3 - quercetin complexation standard method demands high amount of quercetin in spite of its high cost. Hence, developing alternative method that can solve this problem is crucial for the determination of flavonoids in the real sample.

RESULTS

An iron-based complexation method for the determination of flavonoids in the real sample was developed that reduces the amount of quercetin by 200 times (1 mg/mL to 0.005 mg/mL) during the calibration of UV-Vis spectroscopy as an alternative method. The reaction parameters (incubation time, pH, and concentration of quercetin) were optimized using software Design Expert 11 and confirmed by the practical experiments. The kinetics of reaction between iron and quercetin was found to be pseudo first order with rate constant of kobs at 340 and 510 nm. The analysis window for the flavonoid complex was achieved with the kinetic discrimination of the interferences at its optimized time of complexation 20 min and absorbance maxima of 510 nm. The developed method was validated by evaluating its precision, accuracy, recovery test (84-117%), detection limit and quantification limit following the standard protocols. The calibration of the instrument has been developed for the new method and the linear regression coefficient (R2) of 0.998 was obtained.

SIGNIFICANCE

Applying the developed standard material (Fe3+ - quercetin complex) gives freedom for the analytical chemists to find the standard materials that is accessible and cheaper than the existing one (Al3+-quercetin complex). The developed method can also be easily applied for determination of flavonoid in the real samples without potential interferences coming from sample matrix.

Development of nanoparticles incorporated with quercetin and ACE2-membrane as a novel therapy for COVID-19

INTRODUCTION

Angiotensin-converting enzyme 2 (ACE2) and AXL tyrosine kinase receptor are known to be involved in the SARS-CoV-2 entry of the host cell. Therefore, targeting ACE2 and AXL should be an effective strategy to inhibit virus entry into cells. However, developing agents that can simultaneously target ACE2 and AXL remains a formidable task. The natural compound quercetin has been shown to inhibit AXL expression.

MATERIALS AND METHODS

In this study, we employed PLGA nanoparticles to prepare nanoparticles encapsulated with quercetin, coated with ACE2-containing cell membranes, or encapsulated with quercetin and then coated with ACE-2-containing cell membranes. These nanoparticles were tested for their abilities to neutralize or inhibit viral infection.

RESULTS

Our data showed that nanoparticles encapsulated with quercetin and then coated with ACE2-containing cell membrane inhibited the expression of AXL without causing cytotoxic activity. Nanoparticles incorporated with both quercetin and ACE2-containing cell membrane were found to be able to neutralize pseudo virus infection and were more effective than free quercetin and nanoparticles encapsulated with quercetin at inhibition of pseudo virus and SARS-CoV-2 infection.

CONCLUSIONS

We have shown that the biomimetic nanoparticles incorporated with both ACE-2 membrane and quercetin showed the most antiviral activity and may be further explored for clinical application.

Levofloxacin loaded poly (ethylene oxide)-chitosan/quercetin loaded poly (D,L-lactide-co-glycolide) core-shell electrospun nanofibers for burn wound healing

This study developed a new burn wound dressing based on core-shell nanofibers that co-deliver antibiotic and antioxidant drugs. For this purpose, poly(ethylene oxide) (PEO)-chitosan (CS)/poly(D,L-lactide-co-glycolide) (PLGA) core-shell nanofibers were fabricated through co-axial electrospinning technique. Antibiotic levofloxacin (LEV) and antioxidant quercetin (QS) were incorporated into the core and shell parts of PEO-CS/PLGA nanofibers, respectively. The drugs could bond to the polymer chains through hydrogen bonding, leading to their steady release for 168 h. An in vitro drug release study showed a burst effect followed by sustained release of LEV and QS from the nanofibers due to the Fickian diffusion. The NIH 3T3 fibroblast cell viability of the drug loaded core-shell nanofibers was comparable to that in the control (tissue culture polystyrene) implying biocompatibility of the nanofibers and their cell supportive role. However, there was no significant difference in cell viability between the drug loaded and drug free core-shell nanofibers. According to in vivo experiments, PEO-CS-LEV/PLGA-QS core-shell nanofibers could accelerate the healing process of a burn wound compared to a sterile gauze. Thanks to the synergistic therapeutic effect of LEV and QS, a significantly higher wound closure rate was recorded for the drug loaded core-shell nanofibrous dressing than the drug free nanofibers and control. Conclusively, PEO-CS-LEV/PLGA-QS core-shell nanofibers were shown to be a promising wound healing material that could drive the healing cascade through local co-delivery of LEV and QS to burn wounds.

Nanocarriers for the Delivery of Quercetin to Inhibit the UV-Induced Aggregation of γD-Crystallin

Due to gradual environmental changes like ozone layer depletion and global warming, human eyes are exposed to UV light. Exposure to UV light can be a cause of cataracts, one of the ocular diseases that may cause vision impairment. To date, lens replacement has been the only treatment available for cataracts. In our present study, we carried out an extensive examination of polyphenols as inhibitors for UV-induced aggregation of γD-crystallin. On exposure to UV-C light, γD-crystallin forms fibrils instead of amorphous aggregates. Various polyphenols were tested as inhibitors; out of them, quercetin, baicalein, and caffeic acid were found to be effective. As polyphenols are insoluble in water, nanoencapsulation was used to enhance their bioavailability. CS-TPP and CS-PLGA encapsulating systems were considered, as they form biodegradable nanocapsules. Out of three polyphenols (quercetin, baicalein, and caffeic acid), quercetin forms nanocarriers of smaller sizes, a must for crossing the retinal barrier. Quercetin nanocarriers were considered an effective system that could be used for therapeutic applications. For these nanocarriers, encapsulation efficiency and polyphenol release kinetics were studied. CS-PLGA NPs were found to have a better loading efficiency for quercetin than CS-TPP NPs.

PLGA nanomedical consignation: A novel approach for the management of prostate cancer

The malignancy of the prostate is a complicated ailment which impacts millions of male populations around the globe. Despite the multitude of endeavour accomplished within this domain, modalities that are involved in the ameliorative management of predisposed infirmity are still relent upon non-specific and invasive procedures, thus imposing a detrimental mark on the living standard of the individual. Also, the orchestrated therapeutic interventions are still incompetent in substantiating a robust and unabridged therapeutic end point owing to their inadequate solubility, low bioavailability, limited cell assimilation, and swift deterioration, thereby muffling the clinical application of these existing treatment modalities. Nanotechnology has been employed in an array of modalities for the medical management of malignancies. Among the assortment of available nano-scaffolds, nanocarriers composed of a bio-decomposable and hybrid polymeric material like PLGA hold an opportunity to advance as standard chemotherapeutic modalities. PLGA-based nanocarriers have the prospect to address the drawbacks associated with conventional cancer interventions, owing to their versatility, durability, nontoxic nature, and their ability to facilitate prolonged drug release. This review intends to describe the plethora of evidence-based studies performed to validate the applicability of PLGA nanosystem in the amelioration of prostate malignancies, in conjunction with PLGA focused nano-scaffold in the clinical management of prostate carcinoma. This review seeks to explore numerous evidence-based studies confirming the applicability of PLGA nanosystems in ameliorating prostate malignancies. It also delves into the role of PLGA-focused nano-scaffolds in the clinical management of prostate carcinoma, aiming to provide a comprehensive perspective on these advancements.

Anti-UV Microgel Based on Interfacial Polymerization to Decrease Skin Irritation of High Permeability UV Absorber Ethylhexyl Methoxycinnamate

Ethylhexyl methoxycinnamate (EHMC) is frequently employed as a photoprotective agent in sunscreen formulations. EHMC has been found to potentially contribute to health complications as a result of its propensity to produce irritation and permeate the skin. A microgel carrier, consisting of poly(ethylene glycol dimethacrylate) (pEDGMA), was synthesized using interfacial polymerization with the aim of reducing the irritation and penetration of EHMC. The thermogravimetric analysis (TGA) indicated that the EHMC content accounted for 75.72% of the total composition. Additionally, the scanning electron microscopy (SEM) images depicted the microgel as exhibiting a spherical morphology. In this study, the loading of EHMC was demonstrated through FTIR and contact angle tests. The UV resistance, penetration, and skin irritation of the EHMC-pEDGMA microgel were additionally assessed. The investigation revealed that the novel sunscreen compound, characterized by limited dermal absorption, had no irritant effects and offered sufficient protection against ultraviolet radiation.

Rheumatoid Arthritis Treatment Potential of Stearic Acid Nanoparticles of Quercetin in Rats

This study aims to assess the anti-inflammatory potential of stearic acid nanoparticles of quercetin in an arthritic rat model. This article describes the fabrication of solid lipid nanoparticles (SLNs) using the hot melt encapsulation method, followed by the anti-inflammatory study of SLNs and other characterizations such as FTIR, XRD, and SEM. Thirty male healthy albino rats were taken and treated with FCA to induce rheumatoid arthritis. Quercetin loading of quercetin to stearic acid was confirmed by FTIR. The efficacy of quercetin-loaded SLNs to reduce inflammation was evaluated with the help of inflammatory biomarker levels. Quercetin-loaded stearic acid nanoparticles were successfully prepared by using a hot melt encapsulation method. Their average size and zeta potential were 100 nm and -25 mV, respectively. Rheumatoid arthritis was significantly (p < 0.001) reduced in the quercetin-loaded SLN group, as indicated by finding out the reduced levels of inflammatory mediators such as tumor necrosis factor (TNF-α) and rheumatoid factor. Quercetin-loaded stearic acid nanoparticles were found to be potentially effective in treating RA.

Quercetin-Loaded Nanostructured Lipid Carrier In Situ Gel for Brain Targeting Through Intranasal Route: Formulation, In Vivo Pharmacokinetic and Pharmacodynamic Studies

Quercetin (QT) shows potential for protecting against neurodegenerative diseases like Alzheimer's. However, its limited bioavailability and instability in physiological pH hinder its clinical use. The purpose of this work is to construct QT-filled nanostructured lipid carriers (QT-NLC) intranasal in situ gel to enhance pharmacokinetic and pharmacodynamic performance. NLCs were developed using a melt emulsification-high-pressure homogenization and were optimized using design expert software with the Box-Behnken design. NLCs were then incorporated into an in situ gel based on Lutrol F127 and further characterized. The pharmacodynamics of the formulation was evaluated in neurodegeneration induced by trimethyl tin (TMT) Wistar rats. The optimized QT in situ gel had spherical shape, entrapment efficiency of 96.1 ± 4.40%, and in vitro drug release of 83.74 ± 1.40%. The mean particle size was 123.3 ± 5.46 nm. After intranasal administration, in vivo single-dose pharmacokinetic studies demonstrated a significant therapeutic concentration of drug in CNS, having Cmax 183.41 ± 11.76 ng/mL and Tmax of 2 h. The more brain targeting efficiency of NLCs was proved by the developed QT in situ gel, which had a higher drug targeting efficiency (DTE) of 117.47% and drug targeting potential (DTP) of 88.9%. As compared to the neurodegeneration control group, the QT in situ gel-treated group had significantly decreased escape latency and pathlength. Biochemical analysis and histological investigations demonstrated that QT in situ gel exhibited superior anti-Alzheimer's potential compared to standard drug, donepezil. The promising results of the developed and optimized intranasal QT in situ gel suggest its potential and can be used in Alzheimer's disease management.

Polysorbate 80 surface modified PLGA nanoparticles: an in-vitro evaluation of cellular uptake and cytotoxicity on neuro-2a cells

AIM

Present study focuses on the development of P80 coated PLGA Nanoparticles loaded with drugs, paroxetine (P80-Par-PLGA-NPs) and clonidine (P80-CLD-PLGA-NPs) for in-vitro evaluation of Cellular Uptake & Cytotoxicity on Neuro-2a cells.

METHOD

P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs were developed and characterised for zeta size, potential, PDI, EE%, DL%, TEM, SEM, FTIR, DSC, in-vitro release, cytotoxicity, histopathological and cell uptake studies using rhodamine loaded P80-NPs.

RESULT

Mean particle diameter of P80-Par-PLGA-NPs and P80-CLD-PLGA-NPs was 204; 182.7 nm, ZP of -21.8; -18.72 mV and 0.275; 0.341 PDI, respectively. TEM and SEM images revealed homogenous surface morphology. In-vitro drug release showed sustained and complete release in 72 h. Cell viability (>90%) at Cmax and no cytotoxicity in histopathology was observed. Significant higher uptake (96.9%) of P80-modified-NPS was observed as compared to unmodified-NPs (81%) (p < 0.05).

CONCLUSION

The finding clearly indicated a higher cell uptake of drugs via surface modified P80-coated PLGA-NPs as compared to unmodified particles.

Augmentation of anti-proliferative efficacy of quercetin encapsulated chitosan nanoparticles by induction of cell death via mitochondrial membrane permeabilization in oral cancer

Quercetin (QCT), an antioxidant plant flavonoid, is known to impart prominent anti-cancer properties. However, its clinical application as a potential drug is hindered owing to its hydrophobicity, extensive metabolism, low absorption, and rapid elimination. The drawbacks of these phytochemical-based therapies can be addressed using nanotechnology-based drug delivery systems. In this study, we sought to develop chitosan nanoparticles (CSNPs) as the drug vehicle for encasing quercetin (QCT-CSNPs) and further investigate its anti-tumor potential against human oral cancer cell line Cal33. Our findings indicate that the average particle diameter of the formulated chitosan nanoparticles was around 100 nm, and they had a spherical structure, as per the TEM and FESEM images. The efficient entrapment of quercetin inside the CSNPs matrix is confirmed by XRD, UV-Vis spectrophotometry, FTIR, and DSC analysis. The in vitro cell cytotoxicity study against Cal33 oral cancer cells revealed that QCT-CSNPs exhibited superior toxicity compared to free QCT post-24-hour treatment. The improved anti-cancer efficacy of QCT-CSNPs was further confirmed by enhanced cellular apoptosis, colony formation inhibition, migration inhibition, and chromatin condensation. Moreover, the mitochondrial dysfunction and enhanced ROS (Reactive oxygen species) production indicated mitochondrial-mediated cell death in QCT-CSNPs treated Cal33 cells. In conclusion, our data suggest that quercetin-encapsulated chitosan nanoparticles may serve as a potential drug candidate against oral cancer.

Design of Chitosan-Coated, Quercetin-Loaded PLGA Nanoparticles for Enhanced PSMA-Specific Activity on LnCap Prostate Cancer Cells

Nanoparticles are designed to entrap drugs at a high concentration, escape clearance by the immune system, be selectively taken up by cancer cells, and release bioactives in a rate-modulated manner. In this study, quercetin-loaded PLGA nanoparticles were prepared and optimized to determine whether coating with chitosan would increase the cellular uptake of the nanoparticles and if the targeting ability of folic acid as a ligand can provide selective toxicity and enhanced uptake in model LnCap prostate cancer cells, which express high levels of the receptor prostate-specific membrane antigen (PSMA), compared to PC-3 cells, that have relatively low PSMA expression. A design of experiments approach was used to optimize the PLGA nanoparticles to have the maximum quercetin loading, optimal cationic charge, and folic acid coating. We examined the in vitro release of quercetin and comparative cytotoxicity and cellular uptake of the optimized PLGA nanoparticles and revealed that the targeted nano-system provided sustained, pH-dependent quercetin release, and higher cytotoxicity and cellular uptake, compared to the non-targeted nano-system on LnCap cells. There was no significant difference in the cytotoxicity or cellular uptake between the targeted and non-targeted nano-systems on PC-3 cells (featured by low levels of PSMA), pointing to a PSMA-specific mechanism of action of the targeted nano-system. The findings suggest that the nano-system can be used as an efficient nanocarrier for the targeted delivery and release of quercetin (and other similar chemotherapeutics) against prostate cancer cells.

Polymeric Nanoparticles for Delivery of Natural Bioactive Agents: Recent Advances and Challenges

In the last few decades, several natural bioactive agents have been widely utilized in the treatment and prevention of many diseases owing to their unique and versatile therapeutic effects, including antioxidant, anti-inflammatory, anticancer, and neuroprotective action. However, their poor aqueous solubility, poor bioavailability, low GIT stability, extensive metabolism as well as short duration of action are the most shortfalls hampering their biomedical/pharmaceutical applications. Different drug delivery platforms have developed in this regard, and a captivating tool of this has been the fabrication of nanocarriers. In particular, polymeric nanoparticles were reported to offer proficient delivery of various natural bioactive agents with good entrapment potential and stability, an efficiently controlled release, improved bioavailability, and fascinating therapeutic efficacy. In addition, surface decoration and polymer functionalization have opened the door to improving the characteristics of polymeric nanoparticles and alleviating the reported toxicity. Herein, a review of the state of knowledge on polymeric nanoparticles loaded with natural bioactive agents is presented. The review focuses on frequently used polymeric materials and their corresponding methods of fabrication, the needs of such systems for natural bioactive agents, polymeric nanoparticles loaded with natural bioactive agents in the literature, and the potential role of polymer functionalization, hybrid systems, and stimuli-responsive systems in overcoming most of the system drawbacks. This exploration may offer a thorough idea of viewing the polymeric nanoparticles as a potential candidate for the delivery of natural bioactive agents as well as the challenges and the combating tools used to overcome any hurdles.

Polymeric Systems for the Controlled Release of Flavonoids

Flavonoids are natural compounds that are attracting great interest in the biomedical field thanks to the wide spectrum of their biological properties. Their employment as anticancer, anti-inflammatory, and antidiabetic drugs, as well as for many other pharmacological applications, is extensively investigated. One of the most successful ways to increase their therapeutic efficacy is to encapsulate them into a polymeric matrix in order to control their concentration in the physiological fluids for a prolonged time. The aim of this article is to provide an updated overview of scientific literature on the polymeric systems developed so far for the controlled release of flavonoids. The different classes of flavonoids are described together with the polymers most commonly employed for drug delivery applications. Representative drug delivery systems are discussed, highlighting the most common techniques for their preparation. The flavonoids investigated for polymer system encapsulation are then presented with their main source of extraction and biological properties. Relevant literature on their employment in this context is reviewed in relationship to the targeted pharmacological and biomedical applications.

Formulation and Evaluation of Pravastatin Sodium-Loaded PLGA Nanoparticles: In vitro-in vivo Studies Assessment

Purpose

Pravastatin sodium (PVS) is a hypolipidemic drug which suffers from extensive first-pass metabolism and short half-life. Poly(d,l-lactide-co-glycolide) (PLGA) is considered a promising carrier to improve its hypolipidemic and hepatoprotective activities.

Methods

PVS-loaded PLGA nanoparticles (PVS-PLGA-NPs) were prepared by double emulsion method using a full 3² factorial design. The in vitro release and the physical stability studies of the optimized PVS-PLGA-NPs (F5) were performed. Finally, both hypolipidemic and hepatoprotective activities of the optimized F5 NPs were studied and compared to PVS solution.

Results

All the studied physical parameters of the prepared NPs were found in the accepted range. The particle size (PS) ranged from 90 ± 0.125 nm to 179.33 ± 4.509 nm, the poly dispersity index (PDI) ranged from 0.121 ± 0.018 to 0.158 ± 0.014. The optimized NPs (F5) have the highest entrapment efficiency (EE%) (51.7 ± 5%), reasonable PS (168.4 ± 2.506 nm) as well as reasonable zeta potential (ZP) (-28.3 ± 1.18mv). Solid-state characterization indicated that PVS is well entrapped into NPs. All NPs have distinct spherical shape with smooth surface. The prepared NPs showed a controlled release profile. F5 showed good stability at 4 ± 2°C during the whole storage period of 3 months. In vivo study and histopathological examination indicated that F5 NPs showed significant increase in PVS hypolipidemic as well as hepatoprotective activity compared to PVS solution.

Conclusion

The PVS-PLGA-NPs could be considered a promising model to evade the first-pass effect and showed improvement in the hypolipidemic and hepatoprotective activities compared to PVS solution.

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.

Poly(lactic-co-glycolic) Acid (PLGA) Nanoparticles and Transdermal Drug Delivery: An Overview

BACKGROUND

Biodegradable polymeric nanoparticles have garnered pharmaceutical industry attention throughout the past decade. PLGA [Poly(lactic-co-glycolic acid)] is an excellent biodegradable polymer explored for the preparation of nanoparticles that are administered through various routes like intravenous and transdermal. PLGA's versatility makes it a good choice for the preparation of nanoparticles.

OBJECTIVE

The main objective of this review paper was to summarize methods of preparation and characterization of PLGA nanoparticles along with their role in the transdermal delivery of various therapeutic agents.

METHODS

A literature survey for the present review paper was done using various search engines like Pubmed, Google Scholar, and Science Direct.

RESULTS

In comparison to traditional transdermal administration systems, PLGA nanoparticles have demonstrated several benefits in preclinical investigations, including fewer side effects, low dosage frequency, high skin permeability, and simplicity of application.

CONCLUSION

PLGA nanoparticles can be considered efficient nanocarriers for the transdermal delivery of drugs. Nevertheless, the clinical investigation of PLGA nanoparticles for the transdermal administration of therapeutic agents remains a formidable obstacle.

Flavonoids: Food associations, therapeutic mechanisms, metabolism and nanoformulations

Flavonoids possess an impressive therapeutic potential, thereby imparting them a nutraceutical character. As it becomes increasingly common to consume foods associated with healing properties, it is imperative to understand the associations of different foods with different classes of nutraceutic compounds, and their mechanisms of therapeutic action. At the same time, it is important to address the limitations thereof so that plausible future directions may be drawn. This review summarizes the food associations of flavonoids, and discusses the mechanisms responsible for imparting them their nutraceutic properties, detailing the nuclear factor erythroid 2-related factor 2 (NRF2) signaling pathway, inhibition of inflammatory signaling pathways such as toll-like receptor (TLR), nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB), cyclooxygenase 2 (COX-2) and lipoxygenase-2 (LOX-2) mediators. Further on, the review explains the mechanism of flavonoids metabolism, reasons for low bioavailability and thereafter recapitulates the role of technological interventions to overcome the limitations, with a particular focus on nanoformulations that utilize the synergy between flavonoids and biocompatible materials used as nanocarriers, as reported in works spanning over a decade. It is the Generally Recognized as Safe (GRAS) classified carriers that will become the basis for developing functional formulations. It is promisingly noteworthy that some flavonoid formulations have been commercialized and mentioned therein. Such commercially viable and safe for consumption technological applications pave way for bringing science to the table, and add value to the innate properties of flavonoids.

Abemaciclib-loaded ethylcellulose based nanosponges for sustained cytotoxicity against MCF-7 and MDA-MB-231 human breast cancer cells lines

Abemaciclib (AC) is a novel, orally available drug molecule approved for the treatment of breast cancer. Due to its low bioavailability, its administration frequency is two to three times a day that can decrease patient compliance. Sustained release formulation are needed for prolong the action and to reduce the adverse effects. The aim of current study was to develop sustained release NSs of AC. Nanosponges (NSs) was prepared by emulsion-solvent diffusion method using ethyl-cellulose (EC) and Kolliphor P-188 (KP-188) as sustained-release polymer and surfactant, respectively. Effects of varying surfactant concentration and drug: polymer proportions on the particle size (PS), polydispersity index (PDI), zeta potential (ζP), entrapment efficiency (%EE), and drug loading (%DL) were investigated. The results of AC loaded NSs (ACN1-ACN5) exhibited PS (366.3–842.2 nm), PDI (0.448–0.853), ζP (−8.21 to −19.7 mV), %EE (48.45–79.36%) and %DL (7.69–19.17%), respectively. Moreover, ACN2 showed sustained release of Abemaciclib (77.12 ± 2.54%) in 24 h Higuchi matrix as best fit kinetics model. MTT assay signified ACN2 as potentials cytotoxic nanocarrier against MCF-7 and MDA-MB-231 human breast cancer cells. Further, ACN2 displayed drug release property without variation in the % release after exposing the product at 25 °C, 5 °C, and 45 °C storage conditions for six months. This investigation proved that the developed NSs would be an efficient carrier to sustain the release of AC in order to improve efficacy against breast cancer.

α-Acylamino-β-lactone N-Acylethanolamine-hydrolyzing Acid Amidase Inhibitors Encapsulated in PLGA Nanoparticles: Improvement of the Physical Stability and Protection of Human Cells from Hydrogen Peroxide-Induced Oxidative Stress

N-Acylethanolamine acid amidase (NAAA) is an N-terminal cysteine hydrolase that preferentially catalyzes the hydrolysis of endogenous lipid mediators such as palmitoylethanolamide, which has been shown to exhibit neuroprotective and antinociceptive properties by engaging peroxisome proliferator-activated receptor-α. A few potent NAAA inhibitors have been developed, including α-acylamino-β-lactone derivatives, which are very strong and effective, but they have limited chemical and plasmatic stability, compromising their use as systemic agents. In the present study, as an example of a molecule belonging to the chemical class of N-(2-oxo-3-oxetanyl)amide NAAA inhibitors, URB866 was entrapped in poly(lactic-co-glycolic acid) nanoparticles in order to increase its physical stability. The data show a monomodal pattern and a significant time- and temperature-dependent stability of the molecule-loaded nanoparticles, which also demonstrated a greater ability to effectively retain the compound. The nanoparticles improved the photostability of URB866 with respect to that of the free molecule and displayed a better antioxidant profile on various cell lines at the molecule concentration of 25 μM. Overall, these results prove that the use of polymeric nanoparticles could be a useful strategy for overcoming the instability of α-acylamino-β-lactone NAAA inhibitors, allowing the maintenance of their characteristics and activity for a longer time.

Ribociclib-Loaded Ethylcellulose-Based Nanosponges: Formulation, Physicochemical Characterization, and Cytotoxic Potential against Breast Cancer

In the present study, ribociclib-loaded nanosponges (RCNs) composed of ethylcellulose and polyvinyl alcohol were developed using an emulsion-solvent evaporation method. Preliminary evaluations of the developed RCNs (RCN1 to RCN7) were performed in terms of size, polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE), and drug loading (DL), which allowed us to select the optimized formulation. RCN3 was selected as the optimized carrier system with particle size ( $363.5\pm 4.8\text{nm}$ ), PDI ( $0.292\pm 0.012$ ), zeta potential ( $-18.5\pm 0.05\text{mV}$ ), EE ( $81.35\pm 1.64\%$ ), and DL ( $21.96\pm 0.28\%$ ). Further, the optimized nanosponges (RCN3) were subjected to FTIR, XRD, DSC, and SEM studies, and results confirmed the proper encapsulation of the drug within the porous polymeric matrix. In vitro drug release studies showed that the drug release was significantly enhanced with a maximum drug release through RCN3 formulation ( $81.85\pm 0.37\%$ ) and followed the Higuchi model. Moreover, the RCN3 system showed greater cytotoxicity than free ribociclib (RC) against MDA-MB-231 and MCF-7 breast cancer cell lines. The percentage of apoptosis induced by RCN3 was found significantly higher than that of free RC ( $p<0.05$ ). Overall, ribociclib-loaded ethylcellulose nanosponges could be a potential nanocarrier to enhance the effectiveness of ribociclib in breast cancer treatment.

Drug Delivery Strategies for Curcumin and Other Natural Nrf2 Modulators of Oxidative Stress-Related Diseases

Oxidative stress is associated with a wide range of diseases characterised by oxidant-mediated disturbances of various signalling pathways and cellular damage. The only effective strategy for the prevention of cellular damage is to limit the production of oxidants and support their efficient removal. The implication of the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway in the cellular redox status has spurred new interest in the use of its natural modulators (e.g., curcumin, resveratrol). Unfortunately, most natural Nrf2 modulators are poorly soluble and show extensive pre-systemic metabolism, low oral bioavailability, and rapid elimination, which necessitates formulation strategies to circumvent these limitations. This paper provides a brief introduction on the cellular and molecular mechanisms involved in Nrf2 modulation and an overview of commonly studied formulations for the improvement of oral bioavailability and in vivo pharmacokinetics of Nrf2 modulators. Some formulations that have also been studied in vivo are discussed, including solid dispersions, self-microemulsifying drug delivery systems, and nanotechnology approaches, such as polymeric and solid lipid nanoparticles, nanocrystals, and micelles. Lastly, brief considerations of nano drug delivery systems for the delivery of Nrf2 modulators to the brain, are provided. The literature reviewed shows that the formulations discussed can provide various improvements to the bioavailability and pharmacokinetics of natural Nrf2 modulators. This has been demonstrated in animal models and clinical studies, thereby increasing the potential for the translation of natural Nrf2 modulators into clinical practice.

Novel quercetin encapsulated chitosan functionalized copper oxide nanoparticles as anti-breast cancer agent via regulating p53 in rat model

This study was designed to present a new quercetin encapsulated chitosan functionalized copper oxide nanoparticle (CuO-ChNPs-Q) and assessed its anti-breast cancer activity both in vitro and in vivo. The CuO-ChNPs-Q may act as anti-proliferating agent against DMBA-induced mammary carcinoma in female rats. The CuONPs was functionalized with chitosan then quercetin was conjugated with them producing CuO-ChNPs-Q, then characterized. The in vitro anti-proliferating activity of the CuO-ChNPs-Q was evaluated against three human cell line. Then, the anti-breast cancer effect of the CuO-ChNPs-Q was assessed against DMBA-induction compared to both CuONPs and Q in female rat model. The in vitro results proved the potent anticancer activity of the CuO-ChNPs-Q compared to CuONPs and quercetin. The in vivo data showed significant reduction in breast tumors of DMBA-induced rats treated with CuO-ChNPs-Q compared to CuONPs and Q. The CuO-ChNPs-Q treatment had induced apoptosis via increased p53 gene, arrested the cell-cycle, and increased both cytochrome c and caspase-3 levels leading to mammary carcinoma cell death. Also, the CuO-ChNPs-Q treatment had suppressed the PCNA gene which decreased the proliferation of the mammary carcinoma cells. In conclusion, the CuO-ChNPs-Q might be a promising chemotherapeutic agent for treatment of breast cancer with a minimal toxicity on vital organs.

Non-Ionic Surfactants for Stabilization of Polymeric Nanoparticles for Biomedical Uses

Surfactants are essential in the manufacture of polymeric nanoparticles by emulsion formation methods and to preserve the stability of carriers in liquid media. The deposition of non-ionic surfactants at the interface allows a considerable reduction of the globule of the emulsion with high biocompatibility and the possibility of oscillating the final sizes in a wide nanometric range. Therefore, this review presents an analysis of the three principal non-ionic surfactants utilized in the manufacture of polymeric nanoparticles; polysorbates, poly(vinyl alcohol), and poloxamers. We included a section on general properties and uses and a comprehensive compilation of formulations with each principal non-ionic surfactant. Then, we highlight a section on the interaction of non-ionic surfactants with biological barriers to emphasize that the function of surfactants is not limited to stabilizing the dispersion of nanoparticles and has a broad impact on pharmacokinetics. Finally, the last section corresponds to a recommendation in the experimental approach for choosing a surfactant applying the systematic methodology of Quality by Design.

Development and thermochemical characterization of an antioxidant material based on polyhydroxybutyrate electrospun microfibers

The use of antioxidants such as curcumin (Cur) or quercetin (Que) in biomedical and biotechnological applications has been studied owing to their capability to prevent oxidative stress and inhibit free radicals. Using polyhydroxybutyrate (PHB) electrospun fibers is presented as a proper option to encapsulate curcumin and quercetin due to its biocompatibility and biodegradability characteristics. Electrospun fibers were obtained dissolving commercial PHB in chloroform:N,N-dimethylformamide (DMF) (4:1) at 7% m/V, and adding two different concentrations of antioxidant (Cur, and Que) 1%m/m, and 7% m/m. These polymeric solutions were electrospun at different conditions and the obtained fibers were characterized by scanning electron microscopy (SEM), thermogravimetric (TGA) analysis, and Fourier transform infrared spectroscopy (FT-IR). The curcumin and quercetin releases into phosphate buffer saline (PBS) at pH 7.4 were obtained in vitro and measured by spectrophotometry. Antioxidant activities were measured by spectrophotometry in a microplate reader using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. Fibers obtained with different formulations presented a chemical composition in accordance with PHB according to FTIR spectra, the diameters fluctuate between 0.761 ± 0.123 and 1.803 ± 0.557 μm, with qualities over 0.95 according to their morphology, and the melting temperature resulted near 178 °C according to the bibliography. The crystallinity of fibers decreases while curcumin or quercetin concentration increases for the studied interval, indeed, quercetin showed a higher impact on the relative crystallinity of fibers. Antioxidant activity of active compounds is maintained after encapsulation in PHB electrospun fibers, and quercetin resulted in near four times antioxidant activity compared to curcumin according to DPPH analysis.

Formulation and in vitro evaluation of topical nanosponge-based gel containing butenafine for the treatment of fungal skin infection

In the current study, four formulae (BNS1-BNS4) of butenafine (BTF) loaded nanosponges (NS) were fabricated by solvent emulsification technology, using different concentration of ethyl cellulose (EC) and polyvinyl alcohol (PVA) as a rate retarding polymer and surfactant, respectively. Prepared NS were characterized for particle size (PS), polydispersity index (PDI), zeta potential (ZP), entrapment efficiency (EE) and drug loading (DL). Nanocarrier BNS3 was optimized based on the particle characterizations and drug encapsulation. It was further evaluated for physicochemical characterizations; FTIR, DSC, XRD and SEM. Selected NS BNS3 composed of BTF (100 mg), EC (200 mg) and 0.3% of PVA showed, PS (543 ± 0.67 nm), PDI (0.330 ± 0.02), ZP (-33.8 ± 0.89 mV), %EE (71.3 ± 0.34%) and %DL (22.8 ± 0.67%), respectively. Fabricated NS also revealed; polymer-drug compatibility, drug-encapsulation, non-crystalline state of the drug in the spherical NS as per the physicochemical evaluations. Optimized NS (BNS3) with equivalent amount of (1%, w/w or w/v) BTF was incorporated into the (1%, w/w or w/v) carbopol gel. BTF loaded NS based gel was then evaluated for viscosity, spreadability, flux, drug diffusion, antifungal, stability and skin irritation studies. BNS3 based topical gels exhibited a flux rate of 0.18 (mg/cm2.h), drug diffusion of 89.90 ± 0.87% in 24 h with Higuchi model following anomalous non-Fickian drug release. The BNS3 based-gel could be effective against pathogenic fungal strains.

Enlightening the neuroprotective effect of quercetin in epilepsy: From mechanism to therapeutic opportunities

Epilepsy is a devastating neurological disorder characterized by the repeated occurrence of epileptic seizures. Epilepsy stands as a global health concern affecting around 70 million people worldwide. The mainstream antiepileptic drugs (AEDs) only exert symptomatic relief and drug-resistant epilepsy occurs in up to 33 percent of patients. Hence, the investigation of novel therapeutic strategies against epileptic seizures that could exert disease modifying effects is of paramount importance. In this context, compounds of natural origin with potential antiepileptic properties have recently gained increasing attention. Quercetin is a plant-derived flavonoid with several pharmacological activities. Emerging evidence has demonstrated the antiepileptic potential of quercetin as well. Herein, based on the available evidence, we discuss the neuroprotective effects of quercetin against epileptic seizures and further analyze the plausible underlying molecular mechanisms. Our review suggests that quercetin might be a potential therapeutic candidate against epilepsy that deserves further investigation, and paves the way for the development of plant-derived antiepileptic treatment approaches.

Antiviral effect of phytochemicals from medicinal plants: Applications and drug delivery strategies

Viral infections affect three to five million patients annually. While commonly used antivirals often show limited efficacy and serious adverse effects, herbal extracts have been in use for medicinal purposes since ancient times and are known for their antiviral properties and more tolerable side effects. Thus, naturally based pharmacotherapy may be a proper alternative for treating viral diseases. With that in mind, various pharmaceutical formulations and delivery systems including micelles, nanoparticles, nanosuspensions, solid dispersions, microspheres and crystals, self-nanoemulsifying and self-microemulsifying drug delivery systems (SNEDDS and SMEDDS) have been developed and used for antiviral delivery of natural products. These diverse technologies offer effective and reliable delivery of medicinal phytochemicals. Given the challenges and possibilities of antiviral treatment, this review provides the verified data on the medicinal plants and related herbal substances with antiviral activity, as well as applied strategies for the delivery of these plant extracts and biologically active phytochemicals. Graphical Abstract.

Development, Optimization and Characterization of Eudraguard®-based Microparticles for Colon Delivery

Development of pH-dependent systems for colon delivery of natural active ingredients is an attractive area of research in the field of nutraceutical products. This study was focused on Eudraguard^® resins, that are methacrylate copolymers approved as “food grade” by European Commission and useful for the production of food supplements. In particular, Eudraguard^® Biotic (EUG-B), characterized by a pH-dependent solubility and Eudraguard^® Control (EUG-C), whose chemical properties support a prolonged release of the encapsulated compounds, were tested. To obtain EUG microparticles, different preparation techniques were tested, in order to optimize the preparation method and observe the effect upon drug encapsulation and specific colonic release. Unloaded microparticles were initially produced to evaluate the influence of polymer characteristics on the formulation process; subsequently microparticles loaded with quercetin (QUE) as a low solubility model drug were prepared. The characterization of microparticles in the solid-state (FT-IR spectroscopy, differential scanning calorimetry and X-ray diffractometry) indicated that QUE was uniformly dispersed in a non-crystalline state in the polymeric network, without strong signs of chemical interactions. Finally, to assess the ability of EUG-C and EUG-B to control the drug release in the gastric environment, and to allow an increased release at a colonic level, suitable in vitro release tests were carried out by simulating the pH variations along the gastro-intestinal tract. Among the evaluated preparation methods, those in which an aqueous phase was not present, and in particular the emulsion-solvent evaporation method produced the best microparticle systems. The in vitro tests showed a limited drug release at a gastric level and a good specific colon release.

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.