Double-Loaded Doxorubicin/Resveratrol Polymeric Micelles Providing Low Toxicity on Cardiac Cells and Enhanced Cytotoxicity on Lymphoma Cells

Nanomicellar Prodrug Delivery of Glucose-Paclitaxel: A Strategy to Mitigate Paclitaxel Toxicity

Background

Paclitaxel-induced blood system disorders and peripheral neuropathy impede the progress of new formulations in clinical trials.

Purpose of Study

To mitigate these adverse effects by developing and validating a prodrug strategy that encapsulates a glucose-paclitaxel conjugate within nanomicelles.

Material and Methods

Succinic anhydride was used as a bridge to couple C2'-paclitaxel with methyl 2'-glucopyranose and prepare a glucose-paclitaxel conjugate. Nanomicelles were prepared via solid-phase dispersion, and dynamic light scattering was used to determine their average diameter and the polydispersity index. High-performance liquid chromatography (HPLC) was employed to evaluate drug-loading capacity and encapsulation efficiency. Pharmacokinetic studies and in vivo toxicity assays were performed in Sprague-Dawley (SD) rats.

Results

The nanomicellar product exhibited a spherical shape with a particle size distribution between 20-60 nm, a PDI of 0.26 ± 0.01, and an encapsulation efficiency of 95.59 ± 1.73%. The pharmacokinetic profile of glucose-paclitaxel nanomicelles in SD rats was markedly different from that of the paclitaxel solution group. Notably, the plasma drug concentration of glucose-paclitaxel nanomicelles was significantly higher than the paclitaxel solution 15 minutes post-administration, with a Vz at only 40% of that of the paclitaxel solution, while the AUC0-∞ was five times greater than that of the paclitaxel solution. Ultimately, glucose-paclitaxel nanomicelles effectively alleviated blood system disorders and peripheral neuropathy in SD rats.

Conclusion

The encapsulation of glucose-paclitaxel conjugates within nanomicelles presents a viable solution to the dose-limiting toxicities associated with paclitaxel, offering new perspectives on safety for the development of paclitaxel-based therapeutics.

Resveratrol-A Promising Therapeutic Agent with Problematic Properties

Resveratrol is a natural polyphenol (stilbenoid), which can be found in grape skin, red wine, blueberries, peanuts and others. The biological properties of resveratrol, in particular antioxidant, anti-inflammatory, anticancer, estrogenic, vasorelaxant and cardioprotective activity, are the main reason for its importance in medicine and pharmacy. Despite all of its advantages, however, there are many problems related to this polyphenolic substance, such as low stability, water insolubility, poor bioavailability and fast metabolism. For this reason, scientists are currently searching for different approaches to dealing with these problematic properties and improving the therapeutic usage of resveratrol. This review summarizes the mechanisms of the biological effects of resveratrol, determined in vitro and in vivo, and the main limitations of the drug. The article emphasizes new approaches for the improvement of resveratrol delivery, in particular nanoencapsulation, formation of nanocrystals, prodrugs and structure analogues.

The Potential Application of Resveratrol and Its Derivatives in Central Nervous System Tumors

Resveratrol, a naturally occurring polyphenolic compound found in various plants, has been extensively studied for its broad spectrum of beneficial biological effects. These encompass its potent antioxidant properties, anti-inflammatory activities, anti-aging capabilities, cardioprotective functions, and neuroprotective potential. The diverse biological actions of resveratrol extend beyond these well-established properties. It also exerts a significant impact on metabolic processes and bioavailability, and critically, it demonstrates the ability to effectively traverse the blood-brain barrier. This capacity to penetrate the central nervous system renders resveratrol a promising therapeutic agent for the management of central nervous system malignancies, as it has been shown to inhibit tumor cell proliferation, induce apoptosis, and modulate key signaling cascades, such as PI3K/Akt, JAK/STAT, and NF-kB. The multifaceted nature of resveratrol's biological effects, including its influence on diverse physiological processes, underscores its potential as a valuable therapeutic option for the treatment of central nervous system tumors.

Resveratrol-Loaded Pluronic Micelles Ameliorate Scopolamine-Induced Cognitive Dysfunction Targeting Acetylcholinesterase Activity and Programmed Cell Death

Numerous experimental studies suggest the potential for resveratrol (RVT) to be useful in the Alzheimer's disease treatment, but its low bioavailability limits its application. This study aimed to assess the potential of resveratrol-loaded micelles as a neuronal delivery platform to protect rats from scopolamine-induced memory impairment. Resveratrol was incorporated into Pluronic micelles, and the effects of micellar (mRVT) and pure resveratrol (RVT) were compared in the model of scopolamine-induced dementia in male Wistar rats. Memory performance was assessed by a T maze test. The effect of the treatment on specific neurotransmitter levels and protein expression in the cortex and the hippocampus were evaluated biochemically. Our results revealed that the polymeric micelles were in nanoscale (approximately 33 nm) and reached 79% encapsulation efficiency. The treatment with mRVT demonstrated better spatial memory protective effect. The biochemical assays showed that mRVT in a dose of 10 mg/kg enhanced the effects of the pure drug in regard to noradrenalin neurotransmission and acetylcholinesterase inhibitory activity in the hippocampus. Furthermore, micellar resveratrol increased the cAMP-response element-binding protein expression in the cortex and hippocampus of rats as well as the Bcl2/BAX ratio, which indicated an anti-apoptotic effect in the experimental dementia model. In conclusion, our results indicated the potential of a micellar system loaded with resveratrol for neurodegenerative diseases treatment.

Cytoprotective effect of garlic alone versus co-administration of garlic and resveratrol in adriamycin-induced lung toxicity in albino rat: light microscopic, ultrastructural and immunohistochemical study

Adriamycin is a cytotoxic anthracycline antibiotic used to treat a wide variety of cancers. This study was made to detect the possible prophylactic effects of combining garlic and resveratrol in preventing adriamycin-induced pulmonary cytotoxicity. This study was conducted on a total number of 60 adult male albino rats. The rats were divided in an equally random manner into 6 groups: group I rats received nothing, group II received a dose of 50 mg/kg garlic extract orally for 3 weeks, group III received resveratrol in a dose of 20 mg/kg/day orally for 3 weeks, group IV rats were injected with 20 mg/kg adriamycin as a single dose via intraperitoneal route, group V received garlic extract for 3 weeks, then were injected with adriamycin in the same stated doses, and Group VI received garlic extract and resveratrol in same stated dose for 3 weeks, then were injected with adriamycin in the same stated dose. Lung specimens were processed for light microscopic, ultrastructural, and immunohistochemical studies. Adriamycin treatment caused histological alterations, thicker interstitial septa, extensive cellular infiltration, hypertrophied arterial wall, marked inducible Nitric Oxide Synthase immunoreaction, type I pneumocytes with destructed organelles as well as type II pneumocytes having large vacuoles. The combined garlic and resveratrol group demonstrated a considerable improvement in the changes to the histology and ultrastructure of adriamycin-induced lung injury. Combining garlic and resveratrol can prevent adriamycin-induced lung cytotoxicity in albino rats.

pH-Sensitive Fluorescent Probe in Nanogel Particles as Theragnostic Agent for Imaging and Elimination of Latent Bacterial Cells Residing Inside Macrophages

Rhodamine 6G (R6G) and 4-nitro-2,1,3-benzoxadiazole (NBD) linked through a spacer molecule spermidine (spd), R6G-spd-NBD, produces a fluorescent probe with pH-sensitive FRET (Förster (fluorescence) resonance energy transfer) effect that can be useful in a variety of diagnostic applications. Specifically, cancer cells can be spotted due to a local decrease in pH (Warburg effect). In this research, we applied this approach to intracellular infectious diseases-namely, leishmaniasis, brucellosis, and tuberculosis, difficult to treat because of their localization inside macrophages. R6G-spd-NBD offers an opportunity to detect such bacteria and potentially deliver therapeutic targets to treat them. The nanogel formulation of the R6G-spd-NBD probe (nanoparticles based on chitosan or heparin grafted with lipoic acid residues, Chit-LA and Hep-LA) was obtained to improve the pH sensitivity in the desired pH range (5.5-7.5), providing selective visualization and targeting of bacterial cells, thereby enhancing the capabilities of CLSM (confocal laser scanning microscopy) imaging. According to AFM (atomic force microscopy) data, nanogel particles containing R6G-spd-NBD of compact structure and spherical shape are formed, with a diameter of 70-100 nm. The nanogel formulation of the R6G-spd-NBD further improves absorption and penetration into bacteria, including those located inside macrophages. Due to the negative charge of the bacteria surface, the absorption of positively charged R6G-spd-NBD, and even more so in the chitosan derivatives' nanogel particles, is pronounced. Additionally, with a pH-sensitive R6G-spd-NBD fluorescent probe, the macrophages' lysosomes can be easily distinguished due to their acidic pH environment. CLSM was used to visualize samples of macrophage cells containing absorbed bacteria. The created nanoparticles showed a significant selectivity to model E. coli vs. Lactobacillus bacterial cells, and the R6G-spd-NBD agent, being a mild bactericide, cleared over 50% E.coli in conditions where Lactobacillus remained almost unaffected. Taken together, our data indicate that R6G-spd-NBD, as well as similar compounds, can have value not only for diagnostic, but also for theranostic applications.

Phytocompounds and Nanoformulations for Anticancer Therapy: A Review

Cancer is a complex disease that affects millions of people and remains a major public health problem worldwide. Conventional cancer treatments, including surgery, chemotherapy, immunotherapy, and radiotherapy, have limited achievements and multiple drawbacks, among which are healthy tissue damage and multidrug-resistant phenotype onset. Increasing evidence shows that many plants' natural products, as well as their bioactive compounds, have promising anticancer activity and exhibit minimal toxicity compared to conventional anticancer drugs. However, their widespread use in cancer therapy is severely restricted by limitations in terms of their water solubility, absorption, lack of stability, bioavailability, and selective targeting. The use of nanoformulations for plants' natural product transportation and delivery could be helpful in overcoming these limitations, thus enhancing their therapeutic efficacy and providing the basis for improved anticancer treatment strategies. The present review is aimed at providing an update on some phytocompounds (curcumin, resveratrol, quercetin, and cannabinoids, among others) and their main nanoformulations showing antitumor activities, both in vitro and in vivo, against such different human cancer types as breast and colorectal cancer, lymphomas, malignant melanoma, glioblastoma multiforme, and osteosarcoma. The intracellular pathways underlying phytocompound anticancer activity and the main advantages of nanoformulation employment are also examined. Finally, this review critically analyzes the research gaps and limitations causing the limited success of phytocompounds' and nanoformulations' clinical translation.

Targeted Polymeric Micelles System, Designed to Carry a Combined Cargo of L-Asparaginase and Doxorubicin, Shows Vast Improvement in Cytotoxic Efficacy

L-asparaginases (ASP) and Doxorubicin (Dox) are both used in the treatment of leukemia, including in combination. We have attempted to investigate if their combination within the same targeted delivery vehicle can make such therapy more efficacious. We assembled a micellar system, where the inner hydrophobic core was loaded with Dox, while ASP would absorb at the surface due to electrostatic interactions. To make such absorption stronger, we conjugated the ASP with oligoamines, such as spermine, and the lipid components of the micelle-lipoic and oleic acids-with heparin. When loaded with Dox alone, the system yielded about a 10-fold improvement in cytotoxicity, as compared to free Dox. ASP alone showed about a 2.5-fold increase in cytotoxicity, so, assuming additivity of the effect, one could expect a 25-fold improvement when the two agents are applied in combination. But in reality, a combination of ASP + Dox loaded into the delivery system produced a synergy, with a whopping 50× improvement vs. free individual component. Pharmacokinetic studies have shown prolonged circulation of micellar formulations in the bloodstream as well as an increase in the effective concentration of Dox in micellar form and a reduction in Dox accumulation to the liver and heart (which reduces hepatotoxicity and cardiotoxicity). For the same reason, Dox's liposomal formulation has been in use in the treatment of multiple types of cancer, almost replacing the free drug. We believe that an opportunity to deliver a combination of two types of drugs to the same target cell may represent a further step towards improvement in the risk-benefit ratio in cancer treatment.

Enhancing the Bioavailability of Resveratrol: Combine It, Derivatize It, or Encapsulate It?

Overcoming the limited bioavailability and extensive metabolism of effective in vitro drugs remains a challenge that limits the translation of promising drugs into clinical trials. Resveratrol, despite its well-reported therapeutic benefits, is not metabolically stable and thus has not been utilized as an effective clinical drug. This is because it needs to be consumed in large amounts to overcome the burdens of bioavailability and conversion into less effective metabolites. Herein, we summarize the more relevant approaches to modify resveratrol, aiming to increase its biological and therapeutic efficacy. We discuss combination therapies, derivatization, and the use of resveratrol nanoparticles. Interestingly, the combination of resveratrol with established chemotherapeutic drugs has shown promising therapeutic effects on colon cancer (with oxaliplatin), liver cancer (with cisplatin, 5-FU), and gastric cancer (with doxorubicin). On the other hand, derivatizing resveratrol, including hydroxylation, amination, amidation, imidation, methoxylation, prenylation, halogenation, glycosylation, and oligomerization, differentially modifies its bioavailability and could be used for preferential therapeutic outcomes. Moreover, the encapsulation of resveratrol allows its trapping within different forms of shells for targeted therapy. Depending on the nanoparticle used, it can enhance its solubility and absorption, increasing its bioavailability and efficacy. These include polymers, metals, solid lipids, and other nanoparticles that have shown promising preclinical results, adding more "hype" to the research on resveratrol. This review provides a platform to compare the different approaches to allow directed research into better treatment options with resveratrol.

Phytostilbenes in lymphoma: Focuses on the mechanistic and clinical prospects of resveratrol, pterostilbene, piceatannol, and pinosylvin

Lymphoma is a cancer affecting the lymphatic system that fights infections and diseases. In addition to surgery, radiotherapy, and chemotherapy, novel approaches have recently been investigated, such as phytostilbenes in treating lymphoma. Phytostilbenes are natural compounds present in various plants and have been shown to have different therapeutic effects, including anticancer properties. Resveratrol is a main phytostilbene with various derivates followed by pterostilbene and piceatannol. Studies have revealed that phytostilbenes can suppress the growth and proliferation of lymphoma cells by inducing apoptosis and inhibiting specific enzyme activity in cancer cell survival. The compounds also have antiinflammatory effects contributing to reducing lymphoma-associated inflammation. Additionally, phytostilbenes have been shown to increase the immune system's ability to fight cancer cells by activating immune cells (T-cells and natural killer cells). This review investigates the potential therapeutic effects of phytostilbenes, including resveratrol, pterostilbene, piceatannol, and pinosylvin, against lymphoma.

Polymeric-Micelle-Based Delivery Systems for Nucleic Acids

Nucleic acids can modulate gene expression specifically. They are increasingly being utilized and show huge potential for the prevention or treatment of various diseases. However, the clinical translation of nucleic acids faces many challenges due to their rapid clearance after administration, low stability in physiological fluids and limited cellular uptake, which is associated with an inability to reach the intracellular target site and poor efficacy. For many years, tremendous efforts have been made to design appropriate delivery systems that enable the safe and effective delivery of nucleic acids at the target site to achieve high therapeutic outcomes. Among the different delivery platforms investigated, polymeric micelles have emerged as suitable delivery vehicles due to the versatility of their structures and the possibility to tailor their composition for overcoming extracellular and intracellular barriers, thus enhancing therapeutic efficacy. Many strategies, such as the addition of stimuli-sensitive groups or specific ligands, can be used to facilitate the delivery of various nucleic acids and improve targeting and accumulation at the site of action while protecting nucleic acids from degradation and promoting their cellular uptake. Furthermore, polymeric micelles can be used to deliver both chemotherapeutic drugs and nucleic acid therapeutics simultaneously to achieve synergistic combination treatment. This review focuses on the design approaches and current developments in polymeric micelles for the delivery of nucleic acids. The different preparation methods and characteristic features of polymeric micelles are covered. The current state of the art of polymeric micelles as carriers for nucleic acids is discussed while highlighting the delivery challenges of nucleic acids and how to overcome them and how to improve the safety and efficacy of nucleic acids after local or systemic administration.