Cyclodextrin-based nanosponges as promising carriers for active pharmaceutical ingredient

Effective drug distribution at the intended or particular location is a critical issue that researchers are now dealing. Nanosponges have significantly increased in importance in medication delivery using nanotechnology in recent years. An important step toward solving these problems has been the development of nanosponges. Recently created and proposed for use in drug delivery, nanosponge is a unique type of hyper-crosslinked polymer-based colloidal structures made up of solid nanoparticles with colloidal carriers. Nanosponges are solid porous particles that may hold pharmaceuticals and other actives in their nanocavities. They can be made into dosage forms for oral, parenteral, topical, or inhalation use. The targeted distribution of drugs in a regulated manner is greatly aided by nanosponge. The utilization of nanosponges, their benefits, their production processes, the polymers they are made of, and their characterization have all been covered in this review article.

Folate receptor targeted nanoparticles containing niraparib and doxorubicin as a potential candidate for the treatment of high grade serous ovarian cancer

Combination chemotherapy is an established approach used to manage toxicities while eliciting an enhanced therapeutic response. Delivery of drug combinations at specific molar ratios has been considered a means to achieve synergistic effects resulting in improvements in efficacy while minimizing dose related adverse drug reactions. The benefits of this approach have been realized with the FDA approval of Vyxeos®, the first liposome formulation to deliver a synergistic drug combination leading to improved overall survival against standard of care. In the current study, we demonstrate the synergistic potential of the PARP inhibitor niraparib and doxorubicin for the treatment of ovarian cancer. Through in vitro screening in a panel of ovarian cancer cell lines, we find that niraparib and doxorubicin demonstrate consistent synergy/additivity at the majority of evaluated molar ratio combinations. Further to these findings, we report formulation of a nanoparticle encapsulating our identified synergistic combination. We describe a rational design process to achieve highly stable liposomes that are targeted with folate to folate-receptor-alpha, which is known to be overexpressed on the surface of ovarian cancer cells. With this approach, we aim to achieve targeted delivery of niraparib and doxorubicin at a pre-determined synergistic molar ratio via increased receptor-mediated endocytosis.

Cyclodextrin-Based Arsenal for Anti-Cancer Treatments

Anti-cancer drugs are mostly limited in their use due to poor physicochemical and biopharmaceutical properties. Their lower solubility is the most common hurdle limiting their use upto their potential. In the recent years, the cyclodextrin (CD) complexation have emerged as existing approach to overcome the problem of poor solubility. CD-based nano-technological approaches are safe, stable and showed well in vivo tolerance and greater payload for encapsulation of hydrophobic drugs for the targeted delivery. They are generally chosen due to their ability to get self-assembled to form liposomes, nanoparticles, micelles and nano-sponges etc. This review paper describes a birds-eye view of the various CD-based nano-technological approaches applied for the delivery of anti-cancer moieties to the desired target such as CD based liposomes, niosomes, niosoponges, micelles, nanoparticles, monoclonal antibody, magnetic nanoparticles, small interfering RNA, nanorods, miscellaneous formulation of anti-cancer drugs containing CD. Moreover, the author also summarizes the various shortcomings of such a system and their way ahead.

Glucuronides: From biological waste to bio-nanomedical applications

Long considered as no more than biological waste meant to be eliminated in urine, glucuronides have recently contributed to tremendous developments in the biomedical field, particularly against cancer. While glucuronide prodrugs monotherapy and antibody-directed enzyme prodrug therapy have been around for some time, new facets have emerged that combine the unique properties of glucuronides notably in the fields of antibody-drug conjugates and nanomedicine. In both cases, glucuronides are utilized as a vector to improve pharmacokinetics and confer localized activation of potent drugs at tumor sites while also decreasing systemic toxicity. Here we will discuss some of the most promising strategies using glucuronides to promote successful anti-tumor therapeutic treatments.

Chemopreventive Potential of Dietary Nanonutraceuticals for Prostate Cancer: An Extensive Review

There are more than two hundred fifty different types of cancers, that are diagnosed around the world. Prostate cancer is one of the suspicious type of cancer spreading very fast around the world, it is reported that in 2018, 29430 patients died of prostate cancer in the United State of America (USA), and hence it is expected that one out of nine men diagnosed with this severe disease during their lives. Medical science has identified cancer at several stages and indicated genes mutations involved in the cancer cell progressions. Genetic implications have been studied extensively in cancer cell growth. So most efficacious drug for prostate cancer is highly required just like other severe diseases for men. So nutraceutical companies are playing major role to manage cancer disease by the recommendation of best natural products around the world, most of these natural products are isolated from plant and mushrooms because they contain several chemoprotective agents, which could reduce the chances of development of cancer and protect the cells for further progression. Some nutraceutical supplements might activate the cytotoxic chemotherapeutic effects by the mechanism of cell cycle arrest, cell differentiation procedures and changes in the redox states, but in other, it also elevate the levels of effectiveness of chemotherapeutic mechanism and in results, cancer cell becomes less reactive to chemotherapy. In this review, we have highlighted the prostate cancer and importance of nutraceuticals for the control and management of prostate cancer, and the significance of nutraceuticals to cancer patients during chemotherapy.

Givinostat-Liposomes: Anti-Tumor Effect on 2D and 3D Glioblastoma Models and Pharmacokinetics

Glioblastoma is the most common and aggressive brain tumor, associated with poor prognosis and survival, representing a challenging medical issue for neurooncologists. Dysregulation of histone-modifying enzymes (HDACs) is commonly identified in many tumors and has been linked to cancer proliferation, changes in metabolism, and drug resistance. These findings led to the development of HDAC inhibitors, which are limited by their narrow therapeutic index. In this work, we provide the proof of concept for a delivery system that can improve the in vivo half-life and increase the brain delivery of Givinostat, a pan-HDAC inhibitor. Here, 150-nm-sized liposomes composed of cholesterol and sphingomyelin with or without surface decoration with mApoE peptide, inhibited human glioblastoma cell growth in 2D and 3D models by inducing a time- and dose-dependent reduction in cell viability, reduction in the receptors involved in cholesterol metabolism (from -25% to -75% of protein levels), and reduction in HDAC activity (-25% within 30 min). In addition, liposome-Givinostat formulations showed a 2.5-fold increase in the drug half-life in the bloodstream and a 6-fold increase in the amount of drug entering the brain in healthy mice, without any signs of overt toxicity. These features make liposomes loaded with Givinostat valuable as potential candidates for glioblastoma therapy.

Chitosan-Coated Liposomes: The Strategy to Reduce Intestinal Toxicity and Improve Bioavailability of Oral Vinorelbine

In recent years, the oral administration of vinorelbine has gradually replaced intravenous administration in the treatment of several types of tumors. Even though the risk of phlebitis is avoided with oral administration, oral vinorelbine is still not a highly patient-compliant route due to the severe gastrointestinal toxicity. Vinorelbine-loaded liposomes with high encapsulation efficiency and suitable particle size were prepared using the ammonium sulfate gradient method. Chitosan-coated liposomes showed the slowest in vitro release compared to uncoated liposomes and vinorelbine solution. No damage was observed in the intestinal epithelial cells of mice orally administered with coated vinorelbine liposomes due to the low presence of the free drug in the gastrointestinal tract and the LD₅₀ was increased from 129.83 to 182.25 mg/kg compared to oral vinorelbine solution. In addition, the positive surface potential of chitosan-coating endowed liposomes with mucosal adhesive function, delaying the time to reach the peak plasma concentration of vinorelbine from 1 to 4 h after administration. And bioavailability was increased to 2.1-fold compared to vinorelbine solution. In short, a new strategy to address the severe gastrointestinal side effects of oral vinorelbine has been developed.

Multifunctional Lipid Bilayer Nanocarriers for Cancer Immunotherapy in Heterogeneous Tumor Microenvironments, Combining Immunogenic Cell Death Stimuli with Immune Modulatory Drugs

In addition to the contribution of cancer cells, the solid tumor microenvironment (TME) has a critical role in determining tumor expansion, antitumor immunity, and the response to immunotherapy. Understanding the details of the complex interplay between cancer cells and components of the TME provides an unprecedented opportunity to explore combination therapy for intervening in the immune landscape to improve immunotherapy outcome. One approach is the introduction of multifunctional nanocarriers, capable of delivering drug combinations that provide immunogenic stimuli for improvement of tumor antigen presentation, contemporaneous with the delivery of coformulated drug or synthetic molecules that provide immune danger signals or interfere in immune-escape, immune-suppressive, and T-cell exclusion pathways. This forward-looking review will discuss the use of lipid-bilayer-encapsulated liposomes and mesoporous silica nanoparticles for combination immunotherapy of the heterogeneous immune landscapes in pancreatic ductal adenocarcinoma and triple-negative breast cancer. We describe how the combination of remote drug loading and lipid bilayer encapsulation is used for the synthesis of synergistic drug combinations that induce immunogenic cell death, interfere in the PD-1/PD-L1 axis, inhibit the indoleamine-pyrrole 2,3-dioxygenase (IDO-1) immune metabolic pathway, restore spatial access to activated T-cells to the cancer site, or reduce the impact of immunosuppressive stromal components. We show how an integration of current knowledge and future discovery can be used for a rational approach to nanoenabled cancer immunotherapy.

Liposomal PHD2 Inhibitors and the Enhanced Efficacy in Stabilizing HIF-1α

Prolyl hydroxylase domain-containing protein 2 (PHD2) inhibition, which stabilizes hypoxia-inducible factor (HIF)-1α and thus triggers adaptation responses to hypoxia in cells, has become an important therapeutic target. Despite the proven high potency, small-molecule PHD2 inhibitors such as IOX2 may require a nanoformulation for favorable biodistribution to reduce off-target toxicity. A liposome formulation for improving the pharmacokinetics of an encapsulated drug while allowing a targeted delivery is a viable option. This study aimed to develop an efficient loading method that can encapsulate IOX2 and other PHD2 inhibitors with similar pharmacophore features in nanosized liposomes. Driven by a transmembrane calcium acetate gradient, a nearly 100% remote loading efficiency of IOX2 into liposomes was achieved with an optimized extraliposomal solution. The electron microscopy imaging revealed that IOX2 formed nanoprecipitates inside the liposome’s interior compartments after loading. For drug efficacy, liposomal IOX2 outperformed the free drug in inducing the HIF-1α levels in cell experiments, especially when using a targeting ligand. This method also enabled two clinically used inhibitors—vadadustat and roxadustat—to be loaded into liposomes with a high encapsulation efficiency, indicating its generality to load other heterocyclic glycinamide PHD2 inhibitors. We believe that the liposome formulation of PHD2 inhibitors, particularly in conjunction with active targeting, would have therapeutic potential for treating more specifically localized disease lesions.

Redox-sensitive irinotecan liposomes with active ultra-high loading and enhanced intracellular drug release

In this report, a novel irinotecan (IR) encapsulated redox-responsive liposome was developed. The redox-responsive liposomes were prepared based on disulfide phosphatidylcholine (SS-PC), DSPC, DSPE-PEG2000 and cholesterol by ethanol injection method. IR was actively loaded by triethylammonium sucrose octasulfate (TEA8-SOS) gradient method to generate IR/SS-PC liposomes (IR/SS-LP). The particle size of IR/SS-PC was characterized by using dynamic light scattering (DLS) and transmission electron microscopy (TEM). It was found that IR/SS-LP with 30 % content of SS-PC (IR/SS30-LP) had an average size of 125.5 ± 5.8 nm with a negative zeta potential of -19.5 ± 0.1. The encapsulation efficiency (EE) was further determined to be 98.1 ± 0.8 % and drug loading (DL) was 31.8 ± 0.1 %. The redox-responsiveness of IR/SS-LP was investigated by observing the change of particle size and morphology as well as the release behavior of IR triggered by glutathione (GSH). The data indicated GSH breaks the disulfide bonds in SS-PC and leads to the controlled release of IR. At 1 mM GSH, 60.2 % irinotecan was released from IR/SS30-LP within 24 h. Finally, the effects of IR/SS-LP in cell and animal experiments were evaluated in detail. The results showed that IR/SS30-LP had superior pharmacokinetic and antitumor efficacy compared to free irinotecan and traditional irinotecan liposome (ONIVYDE®-like). Taken together, IR/SS30-LP displayed redox-responsive release of IR, ultra-high loading and enhanced anti-tumor activity, which has great potential for clinical application as a new generation of IR liposomal formulation.

Low dose shikonin and anthracyclines coloaded liposomes induce robust immunogenetic cell death for synergistic chemo-immunotherapy

Chemo-immunotherapy based on immunogenic cell death (ICD) is a promising strategy for cancer therapy. However, the effective ICD requires a high dosage of ICD stimulus, which could be associated to a dose-dependent toxicity. Therefore, in this study, a liposome remote-loaded with shikonin (a potent ICD stimulus) was developed, with the ability to effectively induce ICD at high dosage in vivo. However, a hepatotoxic effect was observed. To circumvent this problem, shikonin was combined with the anthracycline mitoxantrone or doxorubicin to develop co-loaded liposomes inducing a synergistic ICD effect and cytotoxicity to tumor cells. Cytotoxicity and uptake experiment in vitro were performed to analyze the optimal synergistic ratio of shikonin and anthracyclines based on a "formulated strategy". Interestingly, copper mediated co-loaded liposomes resulted in a pH and GSH dual-responsive release property. More importantly, pharmacokinetics and tumor biodistribution studies revealed an outstanding capacity of ratiometric delivery of dual drugs. Thus, the dual-loaded liposome enhanced the antitumor effect by the stimulation of a robust immune response at lower doses of the drugs with a higher safety compared to single-loaded liposomes. Summarized, the current work provided a reference for a rational design and development of liposomal co-delivery system of drugs and ICD-induced chemo-immunotherapy, and established a potential clinical application of shikonin-based drug combinations as a new chemo-immunotherapeutic strategy for cancer treatment.

Ratiometric Delivery of Mitoxantrone and Berberine Co-encapsulated Liposomes to Improve Antitumor Efficiency and Decrease Cardiac Toxicity

Combination therapy is one of the most common clinical practices in the treatment of malignancies. Synergistic effects, however, are produced only when optimal ratios of combined drugs were delivered to tumor cells. Thus, carriers co-encapsulating of multiple drugs are widely utilized for coordinated delivery. Herein, co-encapsulated pegylated liposomal formulation of mitoxantrone (MIT) and berberine (BER) at an optimal ratio has been developed (MBL) with high encapsulation efficiency (EE) and drug loading in order to achieve the purpose of ratiometric loading and delivery. MBL can not only extend blood circulation but also enhance tumor accumulation for both MIT and BER. More importantly, MBL can maintain the originally desired drug ratio in tumors within 48 h of intravenous injection for synergistic therapy. Compared with the liposomal formulation of MIT-treated group (ML), the progression of tumor growth was inhibited significantly in murine 4T1 breast tumor model after the treatment of MBL, as well as a lower cardiac toxicity. In addition, MBL evidently prolonged the survival of mice with L1210 ascitic tumor model. In summary, such a strategy of co-encapsulated liposomes could improve the clinical applications against multiple cancers.

A facile and universal method to achieve liposomal remote loading of non-ionizable drugs with outstanding safety profiles and therapeutic effect

Liposomes have made remarkable achievements as drug delivery vehicles in the clinic. Liposomal products mostly benefited from remote drug loading techniques that succeeded in amphipathic and/or ionizable drugs, but seemed impracticable for nonionizable and poorly water-soluble therapeutic agents, thereby impeding extensive promising drugs to hitchhike liposomal vehicles for disease therapy. In this study, a series of weak acid drug derivatives were designed by a simplistic one step synthesis, which could be remotely loaded into liposomes by pH gradient method. Cabazitaxel (CTX) weak acid derivatives were selected to evaluate regarding its safety profiles, pharmacodynamics, and pharmacokinetics. CTX weak acid derivative liposomes were superior to Jevtana® in terms of safety profiles, including systemic toxicity, hematological toxicity, and potential central nerve toxicity. Specifically, it was demonstrated that liposomes had capacity to weaken potential toxicity of CTX on cortex and hippocampus neurons. Significant advantages of CTX weak acid derivative-loaded liposomes were achieved in prostate cancer and metastatic cancer therapy resulting from higher safety and elevated tolerated doses.

Unique flower-like Cur-metal complexes loaded liposomes for primary and metastatic breast cancer therapy

Mounting researches continue to support a favorable role for the drug metal complex against cancer progress and metastasis. However, pharmaceutical barriers were encountered when drug metal complexes needed further pre-clinical and clinical evaluations due to their poor aqueous solubility. In this research, liposomes loaded metal ion as nano-scaled reaction vehicles were used to carry out a synthesis reaction between metal ion and curcumin (Cur) to prepare Cur-metal drug liposomal formulations. The unique flower-like conformation of Cur-M liposomes was observed for the first time and dominated in the Cur-M liposomal formulations system by the cryo-transmission electron microscopy. Different metal ions behaved significant differences in formulations' appearance, release profile, cytotoxic effect against various cell lines, pharmacokinetic profiles, biodistribution and antitumor efficiency. Cur-M liposomes presented enhanced cellular uptake and ROS generation effects, thus augmenting the cytotoxicity of Cur. Superior performances of Cur-copper complexes liposomes were observed in improving Cur stability, promoting apoptosis, inhibiting the proliferation and angiogenesis, therefore enhancing therapeutic effect for primary and metastatic breast cancer. Overall, the current work highlights the potentially significant development value of Cur-M liposomes as an injectable agent for cancer treatment, even superior to the commercial agent Doxil.

Recent Progress in Bioconjugation Strategies for Liposome-Mediated Drug Delivery

In nanoparticle (NP)-mediated drug delivery, liposomes are the most widely used drug carrier, and the only NP system currently approved by the FDA for clinical use, owing to their advantageous physicochemical properties and excellent biocompatibility. Recent advances in liposome technology have been focused on bioconjugation strategies to improve drug loading, targeting, and overall efficacy. In this review, we highlight recent literature reports (covering the last five years) focused on bioconjugation strategies for the enhancement of liposome-mediated drug delivery. These advances encompass the improvement of drug loading/incorporation and the specific targeting of liposomes to the site of interest/drug action. We conclude with a section highlighting the role of bioconjugation strategies in liposome systems currently being evaluated for clinical use and a forward-looking discussion of the field of liposomal drug delivery.

Safety Considerations of Cancer Nanomedicine-A Key Step toward Translation

The rate of translational effort of nanomedicine requires strategic planning of nanosafety research in order to enable clinical trials and safe use of nanomedicine in patients. Herein, the experiences that have emerged based on the safety data of classic liposomal formulations in the space of oncology are discussed, along with a description of the new challenges that need to be addressed according to the rapid expansion of nanomedicine platform beyond liposomes. It is valuable to consider the combined use of predictive toxicological assessment supported by deliberate investigation on aspects such as absorption, distribution, metabolism, and excretion (ADME) and toxicokinetic profiles, the risk that may be introduced during nanomanufacture, unique nanomaterials properties, and nonobvious nanosafety endpoints, for example. These efforts will allow the generation of investigational new drug-enabling safety data that can be incorporated into a rational infrastructure for regulatory decision-making. Since the safety assessment relates to nanomaterials, the investigation should cover the important physicochemical properties of the material that may lead to hazards when the nanomedicine product is utilized in humans.

Improved antitumor activity and tolerability of cabazitaxel derived remote-loading liposomes

The value of the clinical application of chemotherapeutic drugs is dependent on both systemic toxicity and treatment efficacy. Dose intensification and high tolerability suggest the potential for clinical cancer therapy. In this study, we developed a novel strategy for reconstructing a drug molecule into remote-loading liposomes. Two weak-base cabazitaxel derivatives were synthesized, and named CN and CN2. CN exhibited higher cytotoxic effects compared to CN2, and was selected for further study. CN was remotely loaded into nano-size liposomes (CN-LPs) via an ammonium sulfate gradient with high loading and encapsulation efficiency. When compared to the commercial formulation of cabazitaxel, JEVTANA®, CN-LPs showed less systemic toxicity and enhanced tolerability, with at least a 24-fold increase in the tolerated dose. Furthermore, CN-LPs significantly inhibited tumor growth in mice bearing 4T1 and RM-1 xenograft tumors. After intravenous injection, CN-LPs exhibited an extremely high drug concentration in blood, with a 757-fold increase in the area under the curve (AUC). Moreover, 48 h after a single intravenous injection, CN-LPs promoted higher drug accumulation in tumors compared to JEVTANA®. In summary, our liposome delivery system exhibits favorable pharmacologic efficacy and an improved safety profile.

Simple weak-acid derivatives of paclitaxel for remote loading into liposomes and improved therapeutic effects

Liposomes are among the most successful nanocarriers; several products have been marketed, all of which were prepared by active loading methods. However, poorly water-soluble drugs without ionizable groups are usually incorporated into the lipid bi-layer of liposomes by passive loading methods, with serious drug leakage during blood circulation. Furthermore, there have been few improvements in their anti-cancer activity and safety. Herein, we designed and synthesized three weak-acid modified paclitaxel (PTX) derivatives with a one-step reaction for the remote loading of liposomal formulations. By comparison, PTX-succinic acid liposomes (PTX-SA LPs) exhibited the highest encapsulation efficiency (97.2 ± 1.8%) and drug loading (8.84 ± 0.16%); meanwhile, there was almost no change in their particle size or zeta potential within one month. Furthermore, compared with Taxol®, the PTX-SA LPs showed a 4.35-fold prolonged half-time, enhanced tumor accumulation, and an increased maximum tolerated dose (MTD) of more than 30 mg kg⁻¹. As a result, the PTX-SA LPs displayed significantly improved in vivo anti-cancer efficacy in comparison with Taxol®. Therefore, weak-acid modification is proved to be a simple and effective method to achieve remote loading and high encapsulation efficiency of poorly soluble drugs, showing great potential for clinical application.

A remote loading liposomal formulation of weak-acid paclitaxel derivative with high encapsulation efficiency and high drug loading, improved therapeutic efficiency and negligible toxicity.

Core-crosslinked nanomicelles based on crosslinkable prodrug and surfactants for reduction responsive delivery of camptothecin and improved anticancer efficacy

As an important DNA topoisomerase I inhibitor in oncotherapy, camptothecin (CPT) with traditional formulation only shows a limited clinical application mainly because of its poor solubility. In this study, a novel redox responsive nanoscaled delivery system was developed to overcome the inherent defect of CPT. Firstly, a CPT prodrug (CPT-LA) and two crosslinkable surfactants (SO-LA and MPEG-LA) was synthesized, all of which contained the same lipoic acid (LA) structure. In the preparation, highly core-crosslinked structure was formed by adding a thiol crosslinker, which can induce LA ring opening polymerization and disulfide crosslinking. The resulting CPT-LA core-crosslinked nanomicelles (CPT-LA CNM) were formulated with a highly crosslinked core and a PEG hydrophilic shell. Dynamic light scattering (DLS) characterization indicated that CPT-LA CNM possessed a narrow size distribution (184.6 ± 3.6 nm) and negatively charged zeta potential (-3.5 ± 1.2 mV). The storage and physiological stabilities showed that the size distribution of CPT-LA CNM was relatively stable in both conditions which were neutral PBS at 4 °C (1 week period) and PBS containing 10% serum at 37 °C (24 h period). Moreover, the effective CPT release behavior of CPT-LA CNM was confirmed in the reducing circumstances containing dithiothreitol (DTT). Under confocal laser scanning microscopy (CLSM), CPT-LA CNM demonstrated a rapid cellular uptake behavior against cancer cells when compared to CPT suspension. Finally, the enhanced anticancer efficacy of CPT-LA CNM was also detected by in vitro cytotoxicity and cell apoptosis assay. In summary, the core-crosslinked CPT-LA CNM could be a promising CPT delivery system because of high stability, effectively controlled release as well as improved anticancer activity.