Development and optimization of stealth liposomal system for enhanced in vitro cytotoxic effect of quercetin

Factors affecting response variables with emphasis on drug release and loading for optimization of liposomes

Drug delivery through Liposomes has shown tremendous potential in terms of the therapeutic application of nanoparticles. There are several drug-loaded liposomal formulations approved for clinical use that help mitigate harmful effects of life-threatening diseases. Developments in the field of liposomal formulations and drug delivery have made it possible for clinicians and researchers to find therapeutic solutions for complicated medical conditions. A key aspect in the development of drug-loaded liposomes is a careful review of optimization techniques to improve the overall formulation stability and efficacy. Optimization studies help in improving/modulating the various properties of drug-loaded liposomes and are vital for the development of this class of delivery systems. A comprehensive overview of the various process variables and factors involved in the optimization of drug-loaded liposomes is presented in this review. The influence of different independent variables on drug release and loading properties with the application of a statistical experimental design is also explained in this article.

Aspects of quercetin stability and its liposomal enhancement in yellow onion skin extracts

Quercetin is a flavonoid that occurs in many types of fruit and vegetables and is stable for no longer than 4.5 h in the investigated pH range (6.0-8.0), even at 4 °C in the dark. At higher temperatures, the degradation/oxidation process is much faster. Simple but effective proliposomal encapsulation was used to protect the quercetin from environmental conditions such as pH. With this approach, 65 to 90% of pure quercetin and quercetin-rich onion extract was kept after >60 days under conditions that favoured its oxidation (pH 7.4). In addition, the encapsulated quercetin decreases the lipid peroxidation induced by pulsed UV light by >50%. At a mass ratio of 1:100 quercetin to lipids (w/w), the liposomes remained intact in solutions for six months. Quercetin in lipid bilayers simultaneously protects the unsaturated lipids from peroxidation.

Daidzein nanosuspension in combination with cisplatin to enhance therapeutic efficacy against A549 non-small lung cancer cells: an in vitro evaluation

Lung cancer is the most common cause of cancer-related mortality, chemo-resistance, and toxicity limit treatment. The focus is on innovative combined phytotherapy to improve treatment outcomes. Our aim was to investigate the potential effects of daidzein nanosuspension (DZ-NS) and its combination with cisplatin (CIS) on A549 non-small lung cancer cells. Cytotoxicity was investigated using MTT and Chou-Talalay methods. Oxidative, apoptotic, and inflammatory markers were analyzed by ELISA and qRT-PCR. The IC50 value for DZ-NS was 25.23 µM for 24 h and was lower than pure DZ (IC50 = 835 µM for pure DZ). DZ-NS (at IC50x2 and IC50 values) showed synergistic cytotoxicity with CIS. The cells treated with DZ-NS had low TOS and OSI levels. However, DZ-NS failed to regulate Cas3 and TGF-β1 activation in A549 cells. MMP-9 gene expression was significantly suppressed in DZ-NS-treated cells, especially in combination therapy. DZ represents a potential combination option for the treatment of lung cancer, and its poor toxicokinetic properties limit its clinical use. To overcome these limitations, the effects of the nanosuspension formulation were tested. DZ-NS showed a cytotoxic effect on A549 cells and optimized the therapeutic effect of CIS. This in vitro synergistic effect was mediated by suppression of MMP-9 and not by oxidative stress or Cas3-activated apoptosis. This study provides the basis for an in vivo and clinical trial of DZ-NS with concurrent chemotherapy.

Quercetin as a Therapeutic Product: Evaluation of Its Pharmacological Action and Clinical Applications-A Review

Quercetin is the major polyphenolic flavonoid that belongs to the class called flavanols. It is found in many foods, such as green tea, cranberry, apple, onions, asparagus, radish leaves, buckwheat, blueberry, broccoli, and coriander. It occurs in many different forms, but the most abundant quercetin derivatives are glycosides and ethers, namely, Quercetin 3-O-glycoside, Quercetin 3-sulfate, Quercetin 3-glucuronide, and Quercetin 3'-metylether. Quercetin has antioxidant, anti-inflammatory, cardioprotective, antiviral, and antibacterial effects. It is found to be beneficial against cardiovascular diseases, cancer, diabetes, neuro-degenerative diseases, allergy asthma, peptic ulcers, osteoporosis, arthritis, and eye disorders. In pre-clinical and clinical investigations, its impacts on various signaling pathways and molecular targets have demonstrated favorable benefits for the activities mentioned above, and some global clinical trials have been conducted to validate its therapeutic profile. It is also utilized as a nutraceutical due to its pharmacological properties. Although quercetin has several pharmacological benefits, its clinical use is restricted due to its poor water solubility, substantial first-pass metabolism, and consequent low bioavailability. To circumvent this limited bioavailability, a quercetin-based nanoformulation has been considered in recent times as it manifests increased quercetin uptake by the epithelial system and enhances the delivery of quercetin to the target site. This review mainly focuses on pharmacological action, clinical trials, patents, marketed products, and approaches to improving the bioavailability of quercetin with the use of a nanoformulation.

Nanohybrid Based on (Mn, Zn) Ferrite Nanoparticles Functionalized With Chitosan and Sodium Alginate for Loading of Curcumin Against Human Breast Cancer Cells

This study reports on the synthesis of Mn1 - xZnxFe2O4 (Mn, Zn ferrite) magnetic nanoparticles (MNPs) as drug delivery carriers for effective therapeutic outcomes. The MNPs were prepared using the coprecipitation method, and their magnetic properties were investigated based on their composition. Among the compositions tested, Mn0.8Zn0.2Fe2O4 MNPs exhibited superparamagnetic properties with a saturation magnetization moment of 34.6 emu/g at room temperature (25°C). To enhance the water solubility of curcumin (Cur), known for its hydrophobic nature, it was successfully loaded onto alginate (Alg)/chitosan (Chit)@Mn0.8Zn0.2Fe2O4 nanoparticles (NPs). The nanocomposite was characterized by field emission scanning electron microscopy (FE-SEM) which revealed a particle size of approximately 20 nm. The crystalline structure of the NPs was analyzed using X-ray diffraction, while Fourier-transform infrared (FTIR), energy-dispersive X-ray, and map analysis techniques were employed for further characterization. In terms of drug release, there was an initial burst release of Cur (around 18%) within the first hour, followed by a slower release (approximately 61%) over the next 36 h. The anti-tumor properties of the Cur-loaded NPs were evaluated using the Methyl Thiazol Tetrazolium (MTT) assay and quantitative real-time polymerase chain reaction. The MTT assay confirmed a higher cytotoxic effect of Cur-loaded Alg/Chit@Mn0.8Zn0.2Fe2O4 NPs on the MCF-7 breast cancer cell line compared to free Cur, highlighting the significance of incorporating Cur into nano-sized carrier systems.

Delineating effect of headgroup and preparation method on transfection versus toxicity of DNA-loaded lipid nanocarriers

Aim: To perform a parallel comparison of key parameters affecting the safety and efficiency of lipid-based nanovectors (i.e., complexing headgroups, composition and preparation method). Materials & methods: Various cationic and ionizable headgroups were screened for formulating lipoplexes with GFP-plasmid DNA. Ethanol injection and microfluidics were used to prepare nanoparticles with GFP-plasmid DNA complexed on the surface or within the interior of lipid bilayers. Results: Lipoplexes composed of sphingomyelin 102 exhibited the highest transfection efficiency given their higher cellular uptake in BRAF inhibitor-resistant melanoma cells. Lipid nanoparticles demonstrated acceptable transfection efficiency and high spheroid penetration while protecting plasmid DNA under simulated physiological conditions. Conclusion: Selecting the right complexing lipid and preparation method is critical for developing lipid nanocarriers to treat intractable diseases.

Combating Dopaminergic Neurodegeneration in Parkinson's Disease through Nanovesicle Technology

Parkinson's disease (PD) is characterized by dopaminergic neurodegeneration, resulting in dopamine depletion and motor behavior deficits. Since the discovery of L-DOPA, it has been the most prescribed drug for symptomatic relief in PD, whose prolonged use, however, causes undesirable motor fluctuations like dyskinesia and dystonia. Further, therapeutics targeting the pathological hallmarks of PD including α-synuclein aggregation, oxidative stress, neuroinflammation, and autophagy impairment have also been developed, yet PD treatment is a largely unmet success. The inception of the nanovesicle-based drug delivery approach over the past few decades brings add-on advantages to the therapeutic strategies for PD treatment in which nanovesicles (basically phospholipid-containing artificial structures) are used to load and deliver drugs to the target site of the body. The present review narrates the characteristic features of nanovesicles including their blood-brain barrier permeability and ability to reach dopaminergic neurons of the brain and finally discusses the current status of this technology in the treatment of PD. From the review, it becomes evident that with the assistance of nanovesicle technology, the therapeutic efficacy of anti-PD pharmaceuticals, phyto-compounds, as well as that of nucleic acids targeting α-synuclein aggregation gained a significant increment. Furthermore, owing to the multiple drug-carrying abilities of nanovesicles, combination therapy targeting multiple pathogenic events of PD has also found success in preclinical studies and will plausibly lead to effective treatment strategies in the near future.

Recent Progress in Nanotechnology Improving the Therapeutic Potential of Polyphenols for Cancer

Polyphenols derived from fruits, vegetables, and plants are bioactive compounds potentially beneficial to human health. Notably, compounds such as quercetin, curcumin, epigallocatechin-3-gallate (EGCG), and resveratrol have been highlighted as antiproliferative agents for cancer. Due to their low solubility and limited bioavailability, some alternative nanotechnologies have been applied to encapsulate these compounds, aiming to improve their efficacy against cancer. In this comprehensive review, we evaluate the main nanotechnology approaches to improve the therapeutic potential of polyphenols against cancer using in vitro studies and in vivo preclinical models, highlighting recent advancements in the field. It was found that polymeric nanomaterials, lipid-based nanomaterials, inorganic nanomaterials, and carbon-based nanomaterials are the most used classes of nanocarriers for encapsulating polyphenols. These delivery systems exhibit enhanced antitumor activity and pro-apoptotic effects, particularly against breast, lung, prostate, cervical, and colorectal cancer cells, surpassing the performance of free bioactive compounds. Preclinical trials in xenograft animal models have revealed decreased tumor growth after treatment with polyphenol-loaded delivery systems. Moreover, the interaction of polyphenol co-delivery systems and polyphenol-drug delivery systems is a promising approach to increase anticancer activity and decrease chemotherapy side effects. These innovative approaches hold significant implications for the advancement of clinical cancer research.

Development and Characterization of Quercetin-Loaded Delivery Systems for Increasing Its Bioavailability in Cervical Cancer Cells

Quercetin is a natural flavonoid with high anticancer activity, especially for related-HPV cancers such as cervical cancer. However, quercetin exhibits a reduced aqueous solubility and stability, resulting in a low bioavailability that limits its therapeutic use. In this study, chitosan/sulfonyl-ether-β-cyclodextrin (SBE-β-CD)-conjugated delivery systems have been explored in order to increase quercetin loading capacity, carriage, solubility and consequently bioavailability in cervical cancer cells. SBE-β-CD/quercetin inclusion complexes were tested as well as chitosan/SBE-β-CD/quercetin-conjugated delivery systems, using two types of chitosan differing in molecular weight. Regarding characterization studies, HMW chitosan/SBE-β-CD/quercetin formulations have demonstrated the best results, which are obtaining nanoparticle sizes of 272.07 ± 2.87 nm, a polydispersity index (PdI) of 0.287 ± 0.011, a zeta potential of +38.0 ± 1.34 mV and an encapsulation efficiency of approximately 99.9%. In vitro release studies were also performed for 5 kDa chitosan formulations, indicating a quercetin release of 9.6% and 57.53% at pH 7.4 and 5.8, respectively. IC50 values on HeLa cells indicated an increased cytotoxic effect with HMW chitosan/SBE-β-CD/quercetin delivery systems (43.55 μM), suggesting a remarkable improvement of quercetin bioavailability.

Drug delivery challenges and formulation aspects of proteolysis targeting chimera (PROTACs)

Proteolysis targeting chimeras (PROTACs) have been extensively explored for targeted proteasomal degradation of disease-related proteins with enormous potential in the treatment of intractable diseases. However, PROTACs are poorly soluble and permeable bulky molecules facing several bioavailability challenges irrespective of the route of administration. Our review lays out crucial challenges in the delivery of target protein degraders and nanoformulation approaches to overcome physicochemical and biological hurdles that can aid in transporting these target-protein degraders to the disease site. We have elaborated on the current formulation approaches and further highlighted the prospective delivery strategies that could be probed for disease-specific targeted delivery of PROTACs.

Palmitoyl Carnitine-Anchored Nanoliposomes for Neovasculature-Specific Delivery of Gemcitabine Elaidate to Treat Pancreatic Cancer

Being the fourth most fatal malignancy worldwide, pancreatic cancer is on track to become the second leading cause of cancer-related deaths in the United States by 2030. Gemcitabine is a first-line chemotherapeutic agent for pancreatic ductal adenocarcinoma (PDAC). Gemcitabine Elaidate (Gem Elaidate) is a lipophilic derivative which allows hENT1-independent intracellular delivery of gemcitabine and better pharmacokinetics and entrapment in a nanocarrier. Cancer cells and neovasculature are negatively charged compared to healthy cells. Palmitoyl-DL-carnitine chloride (PC) is a Protein kinase C (PKC) inhibitor which also provides a cationic surface charge to nanoliposomes for targeting tumor neovasculature and augmented anticancer potency. The objectives of our study are: (a) to develop and characterize a PKC inhibitor-anchored Gem Elaidate-loaded PEGylated nanoliposome (PGPLs) and (b) to investigate the anticancer activity of Gem Elaidate and PGPLs in 2D and 3D models of pancreatic cancer. The optimized PGPLs resulted in a particle size of 80 ± 2.31 nm, a polydispersity index of 0.15 ± 0.05 and a ζ-potential of +31.6 ± 3.54 mV, with a 93.25% encapsulation efficiency of Gem Elaidate in PGPLs. Our results demonstrate higher cellular uptake, inhibition in migration, as well as angiogenesis potential and significant apoptosis induced by PGPLs in 3D multicellular tumor spheroids of pancreatic cancer cells. Hence, PGPLs could be an effective and novel nanoformulation for the neovasculature-specific delivery of Gemcitabine Elaidate to treat PDAC.

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.

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.

Flavonoids-Based Delivery Systems towards Cancer Therapies

Cancer is the second leading cause of death worldwide. Cervical cancer, for instance, is considered a major scourge in low-income countries. Its development is mostly associated with the human papillomavirus persistent infection and despite the availability of preventive vaccines, they are only widely administered in more developed countries, thus leaving a large percentage of unvaccinated women highly susceptible to this type of cancer. Current treatments are based on invasive techniques, being far from effective. Therefore, the search for novel, advanced and personalized therapeutic approaches is imperative. Flavonoids belong to a group of natural polyphenolic compounds, well recognized for their great anticancer capacity, thus promising to be incorporated in cancer therapy protocols. However, their use is limited due to their low solubility, stability and bioavailability. To surpass these limitations, the encapsulation of flavonoids into delivery systems emerged as a valuable strategy to improve their stability and bioavailability. In this context, the aim of this review is to present the most reliable flavonoids-based delivery systems developed for anticancer therapies and the progress accomplished, with a special focus on cervical cancer therapy. The gathered information revealed the high therapeutic potential of flavonoids and highlights the relevance of delivery systems application, allowing a better understanding for future studies on effective cancer therapy.

Effect of UV-B Radiation on Flavonoids and Phenols Accumulation in Tempisque (Sideroxylon capiri Pittier) Callus

Tempisque (Sideroxylon capiri Pittier) is classified as a threatened species and has been reported with a high content of phenols and flavonoids in the leaves. The use of abiotic elicitors such as radiation has been reported due to the changes it produces in the metabolism of plants by activating their defense mechanisms and increasing the biosynthesis of bioactive compounds with antioxidant capacity such as phenols and flavonoids. Therefore, the aim of this work was to evaluate the effect of UV-B radiation on growth parameters and the synthesis of bioactive compounds in in vitro culture of tempisque callus. For the callus induction, we used thidiazuron (TDZ) and 2,4-dichlorophenoxyacetic acid (2,4-D) at 0, 0.5 and 1 mg/L. Calluses were exposed to UV-B radiation (0, 1, 2, 3 and 4 h/day) for two and four weeks. The highest callus formation index was obtained with TDZ and 2,4-D at 1 mg/mL. The greatest increase in the concentration of phenols and flavonoids was detected in the fourth week with 4 h of exposure per day. The highest concentrations of quercetin (230 µg/g dry weight), kaempferol (235 µg/g dry weight) and gallic acid (240 µg/g dry weight) were found in callus obtained from leaves explants.

Stromal disruption facilitating invasion of a 'nano-arsenal' into the solid tumor

Owing to the indispensable role of nanotechnology in cancer therapy, it is imperative to comprehend every aspect limiting its therapeutic potential. Several preclinical reports have demonstrated the enhanced permeability and retention (EPR)-mediated preferential tumor uptake of nanoparticles. However, the therapeutic outcome of nanotherapeutics is severely compromised by heterogeneous drug distribution and insufficient penetration of nanomedicine in a solid tumor owing to the dense tumor extracellular matrix (ECM). Herein, we elaborate on various preclinically investigated tumor stromal disrupting strategies, which we call 'cannons', to compromise the impenetrable 'fortress-like' solid tumor microenvironment. We have described and summarized major approaches to enhance the penetration of a 'nano-arsenal' in solid tumors. ECM remodeling strategies could be very beneficial in enhancing the therapeutic efficacy of monoclonal antibodies and translational nanomedicine.

Novel Delivery Systems of Polyphenols and Their Potential Health Benefits

Liposome-based delivery systems have been studied and used more frequently in recent years due to their advantages, such as low toxicity, specificity, and the ability to protect the encapsulated substance from environmental factors, which could otherwise degrade the active compound and reduce its effectiveness. Given these benefits, many researchers have encapsulated polyphenols in liposomes, thus increasing their bioavailability and stability. Similarly, polyphenols encapsulated in liposomes are known to produce more substantial effects on targeted cells than unencapsulated polyphenols, while having minimal cytotoxicity in healthy cells. Although polyphenols play a role in preventing many types of disease and generally have beneficial effects on health, we solely focused on their chemopreventive effects on cancer through liposomes in this review. Our goal was to summarize the applicability and efficacy of liposomes encapsulated with different classes of polyphenols on several types of cancer, thus opening the opportunity for future studies based on these drug delivery systems.

Development of Dual ARV-825 and Nintedanib-Loaded PEGylated Nano-Liposomes for Synergistic Efficacy in Vemurafnib-Resistant Melanoma

A novel treatment strategy by co-targeting c-Myc and tumor stroma was explored in vemurafenib-resistant melanoma. BRD4 proteolysis targeting chimera (ARV-825) and nintedanib co-loaded PEGylated nanoliposomes (ARNIPL) were developed to incorporate a synergistic cytotoxic ratio. Both the molecules have extremely poor aqueous solubility. A modified hydration method with citric acid was used to improve the loading of both the molecules in liposomes. ARNIPL with mean particle size 111.1 ± 6.55 nm exhibited more than 90% encapsulation efficiency for both the drugs and was found to be physically stable for a month at 4 °C. Both the molecules and ARNIPL showed significantly higher cytotoxicity, apoptosis and down-regulation of target proteins BRD4 and c-Myc in vemurafenib-resistant cell line (A375R). Vasculogenic mimicry and clonogenic potential of A375R were significantly inhibited by ARNIPL. Tumor growth inhibition in 3D spheroids with reduction of TGF-β1 was observed with ARNIPL treatment. Therefore, ARNIPL could be a promising therapeutic approach for the treatment of vemurafenib-resistant melanoma.