A glance over doxorubicin based-nanotherapeutics: From proof-of-concept studies to solutions in the market

Chondroitin sulfate-functionalized selenium nanoparticle-induced S-phase cell cycle arrest and apoptosis in HeLa Cells

This study aimed to evaluate the anti-cervical cancer activity of chondroitin sulfate-functionalized selenium nanoparticles (SeCS) and to elucidate their action mechanism. Cytotoxic effect of SeCS on HeLa cells was assessed by MTT assay. Further molecular mechanism of SeCS was analyzed by flow cytometric assay and western blotting. The results showed that treatment with SeCS resulted in a dose- and time-dependent inhibition in the proliferation of HeLa cells. The data obtained from flow cytometry demonstrated that SeCS inhibited HeLa cell growth via the induction of S-phase arrest and cell apoptosis. Further mechanism analysis found that SeCS down-regulated expression levels of cyclin A and CDK2 and up-regulated p21 expression, which contributed to S arrest. Moreover, SeCS increased the level of Bax and decreased the expression of Bcl-2, resulting in the release of cytochrome C from mitochondria and activating caspase-3/8/9 for caspase-dependent apoptosis. Meanwhile, intracellular reactive oxygen species (ROS) levels were elevated after SeCS treatment, suggesting that ROS might be upstream of SeCS-induced S-phase arrest and cell apoptosis. These data show that SeCS has anti-tumor effects and possesses the potential to become a new therapeutic agent or adjuvant therapy for cancer patients. PRACTICAL APPLICATION: In our previous study, we used chondroitin sulfate to stabilize nano-selenium to obtain SeCS to improve the bioactivity and stability of nano-selenium. We found that it possessed an inhibitory effect on HeLa cells. However, the molecular mechanism remains unclear. This study elucidated the mechanism of SeCS damage to HeLa cells. SeCS has the potential to become a new therapeutic agent or adjuvant therapy for cancer patients.

Synthesis, biological evaluation, and molecular docking of novel 1,3,4-substituted-thiadiazole derivatives as potential anticancer agent

In an attempt to develop potent anti-cancer agents, a new 1,3,4-substituted-thiadiazole derivatives (8b-g), starting from 4-substituted-thiazol-2-chloroacetamides (4b-g), were synthesized and evaluated for their cytotoxic effects on multiple human cancer cell lines, including the hepatocellular carcinoma (HEPG-2), human lung carcinoma (A549), human breast carcinoma (MCF-7) and pseudo-normal human embryonic liver (L02) cancer cell lines by an MTT assay. Among all synthesized compounds, compound 8d showed the potent anti-cancer activities with GI50 values of 2.98, 2.85 and 2.53 μM against MCF-7, A549 and HepG-2 cell lines respectively as compared to standard drug Doxorubicin. Furthermore, molecular modelling studies have spotlighted the anchoring role of 1,3,4-substituted-thiadiazole moiety in bonding and hydrophobic interaction with the key amino acid residues. Therefore, these results can provide promising starting points for further development of best anti-cancer agents.

Probucol-bile acid nanoparticles: a novel approach and promising solution to prevent cellular oxidative stress in sensorineural hearing loss

The use of antioxidants could thus prove an effective medication to prevent or facilitate recovery from oxidative stress-induced sensorineural hearing loss (SNHL). One promising strategy to prevent SNHL is developing probucol (PB)-based nanoparticles using encapsulation technology and administering them to the inner ear via the established intratympanic route. The preclinical, clinical and epidemiological studies support that PB is a proven antioxidant that could effectively prevent oxidative stress in different study models. Such findings suggest its applicability in preventing oxidative stress within the inner ear and its associated neural cells. However, several hurdles, such as overcoming the blood-labyrinth barrier, ensuring sustained release, minimising systemic side effects and optimising targeted delivery in the intricate inner ear structures, must be overcome to efficiently deliver PB to the inner ear. This review explores the background and pathogenesis of hearing loss, the potential of PB in treating oxidative stress and its cellular mechanisms, and the obstacles linked to inner ear drug delivery for effectively introducing PB to the inner ear.

Synergistic effects of multidrug/material combination deliver system for anti-mutidrug-resistant tumor

Multidrug resistance (MDR) is a public health issue of particular concern, for which nanotechnology-based multidrug delivery systems are considered among the most effective suppressive strategies for such resistance in tumors. However, for such strategies to be viable, the notable shortcomings of reduced loading efficiency and uncontrollable drug release ratio need to be addressed. To this end, we developed a novel "multidrug/material" co-delivery system, using d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS, P-gp efflux pump inhibitor) and poly(amidoamine) (PAMAM) to fabricate a precursor material with the properties of reversing MDR and having a long-cycle. Further, to facilitate multidrug co-delivery, we loaded doxorubicin(Dox) and curcumin(Cur, cardiotoxicity modifier and P-gp inhibitor) into PAMAM-TPGS nano-micelles respectively, and mixed in appropriate proportions. The multidrug/material co-delivery system thus obtained was characterized by high drug loading and a controllable drug release ratio in the physiological environment. More importantly, in vitro and in vivo pharmacodynamic studies indicated that the multidrug/material co-delivery system facilitated the reversal of MDR. Moreover, the system has increased anti-tumor activity and is biologically safe. We accordingly propose that the "multidrug/material" co-delivery system developed in this study could serve as a potential platform for reversing MDR and achieving safe and effective clinical treatment.

Doxorubicin-loaded polymeric nanoparticles containing ketoester-based block and cholesterol moiety as specific vehicles to fight estrogen-dependent breast cancer

The presented research concerns the preparation of polymer nanoparticles (PNPs) for the delivery of doxorubicin. Several block and statistical copolymers, composed of ketoester derivative, N-isopropylacrylamide, and cholesterol, were synthesized. In the nanoprecipitation process, doxorubicin (DOX) molecules were kept in spatial polymeric systems. DOX-loaded PNPs show high efficacy against estrogen-dependent MCF-7 breast cancer cell lines despite low doses of DOX applied and good compatibility with normal cells. Research confirms the effect of PNPs on the degradation of the biological membrane, and the accumulation of reactive oxygen species (ROS), and the ability to cell cycle arrest are strictly linked to cell death.

Graphical Abstract

Polysaccharide-based nanoassemblies: From synthesis methodologies and industrial applications to future prospects

Polysaccharides, due to their remarkable features, have gained significant prominence in the sustainable production of nanoparticles (NPs). High market demand and minimal production cost, compared to the chemically synthesised NPs, demonstrate a drive towards polysaccharide-based nanoparticles (PSNPs) benign to environment. Various approaches are used for the synthesis of PSNPs including cross-linking, polyelectrolyte complexation, and self-assembly. PSNPs have the potential to replace a wide diversity of chemical-based agents within the food, health, medical and pharmacy sectors. Nevertheless, the considerable challenges associated with optimising the characteristics of PSNPs to meet specific targeting applications are of utmost importance. This review provides a detailed compilation of recent accomplishments in the synthesis of PSNPs, the fundamental principles and critical factors that govern their rational fabrication, as well as various characterisation techniques. Noteworthy, the multiple use of PSNPs in different disciplines such as biomedical, cosmetics agrochemicals, energy storage, water detoxification, and food-related realms, is accounted in detail. Insights into the toxicological impacts of the PSNPs and their possible risks to human health are addressed, and efforts made in terms of PSNPs development and optimising strategies that allow for enhanced delivery are highlighted. Finally, limitations, potential drawbacks, market diffusion, economic viability and future possibilities for PSNPs to achieve widespread commercial use are also discussed.

Temperature and pH-responsive PNIPAM@PAA Nanospheres with a Core-Shell Structure for Controlled Release of Doxorubicin in Breast Cancer Treatment

Stimuli-responsive polymers have been of great interest in the fabrication of advanced drug delivery systems. In this study, a facile approach was developed to synthesize a dually temperature/pH-responsive drug delivery system with a core-shell structure to control the release of doxorubicin (DOX) at the target site. For this purpose, poly(acrylic acid) (PAA) nanospheres were first synthesized using the precipitation polymerization technique and were used as pH-responsive polymeric cores. Then, poly(N-isopropylacrylamide) (PNIPAM) with thermo-responsivity properties was coated on the outer surface of PAA cores via seed emulsion polymerization technique to render monodisperse PNIPAM-coated PAA (PNIPAM@PAA) nanospheres. The optimized PNIPAM@PAA nanospheres with an average particle size of 116.8 nm (PDI= 0.243), had a high negative surface charge (zeta potential= -47.6 mV). Then, DOX was loaded on PNIPAM@PAA nanospheres and the entrapment efficiency (EE) and drug loading (DL) capacity were measured to be 92.7% and 18.5%, respectively. The drug-loaded nanospheres exhibited a low leakage at neutral pH and physiological temperature, but drug release significantly enhanced at acidic pH (pH= 5.5), indicating the tumor-environment responsive drug release behavior of the prepared nanospheres. Also, kinetics studies showed that, the sustained release of DOX from PNIPAM@PAA nanospheres was consistent with the Fickian diffusion mechanism. Moreover, the anticancer efficacy of DOX-loaded nanospheres was evaluated in vitro against MCF-7 breast cancer cells. The obtained results revealed that, the incorporation of DOX into PNIPAM@PAA nanospheres increases its cytotoxicity against cancer cells compared to the free DOX. Our results suggest that, PNIPAM@PAA nanospheres can be considered as a promising vector to release anticancer drugs with dual-stimuli responsivity to pH and temperature.

Glycomimetics for the inhibition and modulation of lectins

Carbohydrates are essential mediators of many processes in health and disease. They regulate self-/non-self- discrimination, are key elements of cellular communication, cancer, infection and inflammation, and determine protein folding, function and life-times. Moreover, they are integral to the cellular envelope for microorganisms and participate in biofilm formation. These diverse functions of carbohydrates are mediated by carbohydrate-binding proteins, lectins, and the more the knowledge about the biology of these proteins is advancing, the more interfering with carbohydrate recognition becomes a viable option for the development of novel therapeutics. In this respect, small molecules mimicking this recognition process become more and more available either as tools for fostering our basic understanding of glycobiology or as therapeutics. In this review, we outline the general design principles of glycomimetic inhibitors (Section 2). This section is then followed by highlighting three approaches to interfere with lectin function, i.e. with carbohydrate-derived glycomimetics (Section 3.1), novel glycomimetic scaffolds (Section 3.2) and allosteric modulators (Section 3.3). We summarize recent advances in design and application of glycomimetics for various classes of lectins of mammalian, viral and bacterial origin. Besides highlighting design principles in general, we showcase defined cases in which glycomimetics have been advanced to clinical trials or marketed. Additionally, emerging applications of glycomimetics for targeted protein degradation and targeted delivery purposes are reviewed in Section 4.

Pharmacokinetic behaviors of soft nanoparticulate formulations of chemotherapeutics

Chemotherapeutic treatment with conventional drug formulations pose numerous challenges, such as poor solubility, high cytotoxicity and serious off-target side effects, low bioavailability, and ultimately subtherapeutic tumoral concentration leading to poor therapeutic outcomes. In the field of Nanomedicine, advances in nanotechnology have been applied with great success to design and develop novel nanoparticle-based formulations for the treatment of various types of cancer. The approval of the first nanomedicine, Doxil® (liposomal doxorubicin) in 1995, paved the path for further development for various types of novel delivery platforms. Several different types of nanoparticles, especially organic (soft) nanoparticles (liposomes, polymeric micelles, and albumin-bound nanoparticles), have been developed and approved for several anticancer drugs. Nanoparticulate drug delivery platform have facilitated to overcome of these challenges and offered key advantages of improved bioavailability, higher intra-tumoral concentration of the drug, reduced toxicity, and improved efficacy. This review introduces various commonly used nanoparticulate systems in biomedical research and their pharmacokinetic (PK) attributes, then focuses on the various physicochemical and physiological factors affecting the in vivo disposition of chemotherapeutic agents encapsulated in nanoparticles in recent years. Further, it provides a review of the current landscape of soft nanoparticulate formulations for the two most widely investigated anticancer drugs, paclitaxel, and doxorubicin, that are either approved or under investigation. Formulation details, PK profiles, and therapeutic outcomes of these novel strategies have been discussed individually and in comparison, to traditional formulations. This article is categorized under: Nanotechnology Approaches to Biology > Cells at the Nanoscale Diagnostic Tools > In Vivo Nanodiagnostics and Imaging Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

Development and DoE-ANN based optimization of novel swellable matrix-diffusible doxorubicin loaded zinc oxide nanoflowers using sonochemical-precipitation method

This research aimed to acquire doxorubicin loaded zinc oxide nanoflowers (DOX-ZnO-NFs) for intracellular drug cargo possessing a synergistic in-vitro anticancer activity with minimal toxicity. Zinc is the main inorganic metallic component of various enzyme systems and has the possibility of fabrication into the diverse nano-structural forms. An easy absorption and extensive tissue distribution of zinc have made it unique candidate for drug delivery system. Hence, the zinc oxide nanoflowers were prepared with sonochemical-precipitation. The developed system was characterized using the reported methods and was optimized employing design of experiment, coupled with artificial neural network approach. The optimized nanoflowers (DOX-ZnO-NFV) were anionic with particle size of 24 ± 0.05 nm, polydispersity index of <0.5, a zeta potential of -25.68 ± 0.16 mV, yield of 87.40% and encapsulation efficiency of 85.25%. DOX-ZNO-NFV depicted sustained DOX release, around 65.413% release in 30 h at pH 7.4 and assumed Weibull model with its derived parameters, a and b of 22.77 and 0.918, respectively. DOX-ZnO-NFV remained stable on storage for 3 months at 4° C/50% RH and 25° C/60% RH. DOX-ZnO-NFV displayed a zone of inhibition of 13.50 ± 1.25 mm and 25.50 ± 0.98 mm, respectively against gram-positive Staphylococcus aureus and gram-negative Escherichia coli strains, presenting the nanoflowers as self-preservative. DOX-ZnO-NFV exhibited higher in-vitro anticancer activity in Henrietta Lacks cell line, with least hemolysis compared to the free DOX and ZnO-NF. Thus, doxorubicin loaded zinc oxide nanoflowers envisioned to act as better chemotherapeutic cargos with the maximize anticancer activity and minimal toxicity.

Gliadin Nanoparticles Containing Doxorubicin Hydrochloride: Characterization and Cytotoxicity

Doxorubicin hydrochloride (DOX) is a well-known antitumor drug used as first line treatment for many types of malignancies. Despite its clinical relevance, the administration of the compound is negatively affected by dose-dependent off-target toxicity phenomena. Nanotechnology has helped to overcome these important limitations by improving the therapeutic index of the bioactive and promoting the translation of novel nanomedicines into clinical practice. Herein, nanoparticles made up of wheat gliadin and stabilized by polyoxyethylene (2) oleyl ether were investigated for the first time as carriers of DOX. The encapsulation of the compound did not significantly affect the physico-chemical features of the gliadin nanoparticles (GNPs), which evidenced a mean diameter of ~180 nm, a polydispersity index < 0.2 and a negative surface charge. The nanosystems demonstrated great stability regarding temperature (25−50 °C) and were able to retain high amounts of drug, allowing its prolonged and sustained release for up to a week. In vitro viability assay performed against breast cancer cells demonstrated that the nanoencapsulation of DOX modulated the cytotoxicity of the bioactive as a function of the incubation time with respect to the free form of the drug. The results demonstrate the potential use of GNPs as carriers of hydrophilic antitumor compounds.

Enhanced Nuclear Accumulation of Doxorubicin Delivered by pH-Triggered Polydopamine-Shelled Mesoporous Silica for Chemo-Photothermal Therapy

Adequate delivery of therapeutic agents to their intended molecular targets is crucial in tumor therapy. Versatile drug carriers need to overcome the challenges coming from the systemic circulation, membrane barriers, and endo-lysosomal degradation. Herein, hyaluronic acid-conjugated polydopamine (HA-PDA)-shelled mesoporous silica nanoparticles encapsulated with doxorubicin (MSNs-DOX) were successfully fabricated for targeted tumor therapy. Compared with reported studies focusing on the pH-sensitive release in tumors, we especially revealed the significant role of lysosomal release in DOX nuclear accumulation. After active targeting and CD44-mediated endocytosis in tumor cells, the PDA layer of the nanoparticles would be peeled off to trigger drug release owing to MSNs gatekeeper in acidic lysosomes. Subsequently, DOX molecules passively diffused into nuclei. The intracellular DOX transportation was evidenced by DOX accumulation in nuclei, lysosomal location of nanoparticles, and lysosome acidification inhibition test. After discharging of the cargoes from nanoparticles, PDA shells from residual nanoparticles were able to produce localized hyperthermia under NIR irradiation entrapped in lysosomes, inducing synergistic chemo-photothermal effect. Under NIR treatment, HA-PDA@MSNs-DOX presented a prominent tumor inhibition rate without obvious side effects. This study indicated the potent nuclear delivery and synergetic chemo-photothermal therapy achieved by HA-PDA-shelled MSNs.

New Nanosized Systems Doxorubicin-Amphiphilic Copolymers of N-Vinylpyrrolidone and (Di)methacrylates with Antitumor Activity

Nanosized systems of DOX with antitumor activity on the base of micelle-like particles of amphiphilic thermosensitive copolymers of N-vinylpyrrolidone (VP) with triethylene glycol dimethacrylate (TEGDM), and N-vinylpyrrolidone and methacrylic acid (MAA) with TEGDM were explored. They were investigated in aqueous solutions by electron absorption spectroscopy, dynamic light scattering and cyclic voltammetry. Experimental data and quantum-chemical modeling indicated the formation of a hydrogen bond between oxygen-containing groups of monomer units of the copolymers and H-atoms of OH and NH₂ groups of DOX; the energies and H-bond lengths in the considered structures were calculated. A simulation of TDDFT spectra of DOX and its complexes with the VP and TEGDM units was carried out. Electrochemical studies in PBS have demonstrated that the oxidation of encapsulated DOX appeared to be easier than that of the free one, and its reduction was somewhat more difficult. The cytotoxicity of VP-TEGDM copolymer compositions containing 1, 5 and 15 wt% DOX was studied in vitro on HeLa cells, and the values of IC₅₀ doses were determined at 24 and 72 h of exposure. The copolymer compositions containing 5 and 15 wt% DOX accumulated actively in cell nuclei and did not cause visual changes in cell morphology.

Light-activated nanomaterials for tumor immunotherapy

Tumor immunotherapy mainly relies on activating the immune system to achieve antitumor treatment. However, the present tumor immunotherapy used in the clinic showed low treatment efficacy with high systematic toxicity. To overcome the shortcomings of traditional drugs for immunotherapy, a series of antitumor immunotherapies based on nanomaterials have been developed to enhance the body’s antitumor immune response and reduce systematic toxicity. Due to the noninvasiveness, remote controllability, and high temporal and spatial resolution of light, photocontrolled nanomaterials irradiated by excitation light have been widely used in drug delivery and photocontrolled switching. This review aims to highlight recent advances in antitumor immunotherapy based on photocontrolled nanomaterials. We emphasized the advantages of nanocomposites for antitumor immunotherapy and highlighted the latest progress of antitumor immunotherapy based on photoactivated nanomaterials. Finally, the challenges and future prospects of light-activated nanomaterials in antitumor immunity are discussed.

Doxorubicin-induced cardiotoxicity: causative factors and possible interventions

OBJECTIVES

Doxorubicin (Dox) belongs to the anthracycline drug classification and is a widely administered chemotherapeutic. However, Dox use in therapy is limited by its cardiotoxicity, representing a significant drawback of Dox treatment applicability. A large amount of current research is on reducing Dox-induced cardiotoxicity by developing targeted delivery systems and investigating cardiotoxicity mechanisms. Recently, discrepancies have challenged the traditional understanding of Dox metabolism, mechanisms of action and cardiotoxicity drivers. This review summarises the current knowledge around Dox's metabolism, mechanisms of anticancer activity, and delivery systems and offers a unique perspective on the relationships between several proposed mechanisms of Dox-induced cardiotoxicity.

KEY FINDINGS

While there is a strong understanding of Dox's pharmacokinetic properties, it is unclear which enzymes contribute to Dox metabolism and how Dox induces its cytotoxic effect in neoplastic and non-neoplastic cells. Evidence suggests that there are several potentially synergistic mechanisms involved in Dox-induced cardiotoxicity.

SUMMARY

It has become clear that Dox operates in a multifactorial fashion dependent on cellular context. Accumulation of oxidative stress appears to be a common factor in cardiotoxicity mechanisms, highlighting the importance of novel delivery systems and antioxidant therapies.

Metal complex-based liposomes: Applications and prospects in cancer diagnostics and therapeutics

Metal complexes are of increasing interest as pharmaceutical agents in cancer diagnostics and therapeutics, while some of them suffer from issues such as limited water solubility and severe systemic toxicity. These drawbacks severely hampered their efficacy and clinical applications. Liposomes hold promise as delivery vehicles for constructing metal complex-based liposomes to maximize the therapeutic efficacy and minimize the side effects of metal complexes. This review provides an overview on the latest advances of metal complex-based liposomal delivery systems. First, the development of metal complex-mediated liposomal encapsulation is briefly introduced. Next, applications of metal complex-based liposomes in a variety of fields are overviewed, where drug delivery, cancer imaging (single photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI)), and cancer therapy (chemotherapy, phototherapy, and radiotherapy) were involved. Moreover, the potential toxicity, action of toxic mechanisms, immunological effects of metal complexes as well as the advantages of metal complex-liposomes in this content are also discussed. In the end, the future expectations and challenges of metal complex-based liposomes in clinical cancer therapy are tentatively proposed.

An Acid-Sensitive Nanofiber Conjugate Based on a Short Aromatic Peptide for Targeted Delivery of Doxorubicin in Liver Cancer

Purpose

This study aimed to construct a DOX conjugate with liver tumor targeting and acid sensitivity based on a short aromatic peptide FFYEE, which could amplify the tumor inhibition efficacy of DOX and alleviate tissue toxicity.

Methods

A novel DOX-peptide conjugate, D-gal-FFYEE-hyd-DOX, was constructed by linking DOX to the side chain of FFYEE with acid-sensitive hydrazone bond and by modifying the C-terminal of peptide with α-D-galactosamine (D-gal) as targeting ligand. The structure of D-gal-FFYEE-hyd-DOX was characterized by mass spectrometry, infrared spectroscopy (IR), and UV-Vis spectroscopy (UV-Vis). The assembly characteristics of pentapeptide FFYEE and D-gal-FFYEE-hyd-DOX were observed by transmission electron microscope (TEM). In vitro drug release, cytotoxicity, endocytosis, in vivo antitumor experiment and histopathology analysis were investigated.

Results

Peptide FFYEE endowed the D-gal-FFYEE-hyd-DOX with self-assembly performance and improved biocompatibility. D-gal-FFYEE-hyd-DOX can self-assemble into nanofibers with a diameter of ~ 40 nm in neutral aqueous solution and significantly reduced the cytotoxicity of free DOX to L02 cells. In vitro drug release results showed that D-gal-FFYEE-hyd-DOX had acid sensitivity and controlled release characteristics. The cytotoxicity and endocytosis investigations confirmed that D-gal-FFYEE-hyd-DOX enhanced the cellular uptake of DOX and inhibition effect on HepG2 cells. In vivo antitumor experiment indicated that D-gal-FFYEE-hyd-DOX could significantly inhibit the growth of liver tumor in mice and reduce the side effects of DOX.

Conclusion

The conjugate D-gal-FFYEE-hyd-DOX with liver tumor targeting and acid sensitivity has the characteristics of strong tumor inhibition and low toxicity, hinting the great clinical application potential for targeted delivery of DOX in cancer treatment.

Complex polymeric nanomicelles co-delivering doxorubicin and dimethoxycurcumin for cancer chemotherapy

Combinational therapy is a new trend in medical sciences to achieve a maximum therapeutic response of the drugs with a comparatively low incidence of severe adverse effects. To overcome the challenges of conventional formulations for cancer chemotherapy, a polymer-based complex nanomicellar system, namely CPM-DD, was developed co-delivering the anti-cancer agent doxorubicin (DOX) and potent antioxidant dimethoxycurcumin (DiMC). The optimal mass ratio of DOX/DiMC in CPM-DD was determined as 1:6 due to the synergistic antiproliferative effect from in vitro cytotoxicity assay, while the biocompatible diblock copolymer of mPEG2000-PLA5000 was selected for drug entrapment at an optimal feeding ratio of 9:1 to both drugs together. The uniform particles of CPM-DD with suitable particle size (∼30 nm) and stable drug loading content (>9%) could be reliably obtained by self-assembly with the encapsulation yield up to 95%. Molecular dynamics simulation revealed the interaction mechanism responsible for forming these complex nanomicelles. The acid-base interaction between two drugs would significantly improve their binding with the copolymer, thus leading to good colloidal stability and controlled drug release characteristics of CPM-DD. Systematic evaluation based on the MCF-7 breast tumor-bearing nude mice model further demonstrated the characteristics of tissue biodistribution of both drugs delivered by CPM-DD, which were closely related to the drug loading pattern and greatly responsible for the improved anti-cancer potency and attenuated toxicity of this complex formulation. Therefore, all the findings indicated that CPM-DD would be a good alternative to the conventional formulations of DOX and worthy of clinical application for cancer chemotherapy.

Ultrasmall Nanoparticle Delivery of Doxorubicin Improves Therapeutic Index for High-Grade Glioma

Purpose: Despite dramatic growth in the number of small molecule drugs developed to treat solid tumors, durable therapeutic options to control primary central nervous system malignancies are relatively scarce. Chemotherapeutic agents which appear biologically potent in model systems have often been found to be marginally effective at best when given systemically in clinical trials. This work presents for the first time an ultrasmall (&lt; 8 nm) multimodal core-shell silica nanoparticle, Cornell prime dots (or C' dots), for the efficacious treatment of high-grade gliomas. Experimental Design: This work presents first-in-kind renally-clearable ultrasmall (&lt; 8 nm) multimodal Cornell prime dots (or C' dots) with surface-conjugated doxorubicin via pH-sensitive linkers for the efficacious treatment in two different clinically relevant high-grade glioma models. Results: Optimal drug-per-particle ratios of as-developed nanoparticle-drug conjugates were established and used to obtain favorable pharmacokinetic profiles. The in vivo efficacy results showed significantly improved biological, therapeutic, and toxicological properties over the native drug after intravenous administration in platelet-derived growth factor-driven genetically engineered mouse model, and an epidermal growth factor expressing patient-derived xenograft (EGFR PDX) model. Conclusions: Ultrasmall C' dot-drug conjugates showed great translational potential over doxorubicin for improving the therapeutic outcome of patients with high-grade gliomas, even without a cancer-targeting moiety.

Bone morphogenetic protein 10 alleviates doxorubicin-induced cardiac injury via signal transducer and activator of transcription 3 signaling pathway

Doxorubicin (DOX) has limited antitumor applications owing to its association with life-threatening cardiac injury. Oxidative damage and cardiac apoptosis are crucial in DOX-induced cardiac injury. Bone morphogenetic protein 10 (BMP10) is predominantly distributed in the heart and acts as a cardioprotective factor that preserves cardiac function. However, the role of BMP10 in DOX-induced cardiac injury has not yet been explored. The current study aimed to examine the function and mechanism of action of BMP10 in DOX-induced cardiac injury. An adeno-associated viral system was used for the overexpression or silencing of cardiac-specific BMP10, and subsequently, a single dose of DOX was intraperitoneally injected to induce cardiac injury. Results showed that DOX exposure decreased BMP10 expression in the heart. Cardiac-specific overexpression of BMP10 alleviated the oxidative stress and apoptosis and improved cardiac function. Conversely, cardiac-specific silencing of BMP10 aggravated the redox disorder and apoptosis and worsened the cardiac dysfunction caused by DOX. Exogenous BMP10 supplementation amelioratesd the DOX-induced cardiac contractile dysfunction. Mechanistically, we found that phosphorylation of signal transducer and activator of transcription 3 (STAT3) is reduced in DOX-induced cardiotoxicity, and, BMP10 activated impaired STAT3 via a non-canonical pathway. BMP10 lost its cardioprotective function in cardiomyocyte-specific STAT3 knockout (STAT3-cKO) mice. Based on our findings, we suggested that BMP10 is a potential therapeutic agent against DOX-induced cardiac injury and that the cardioprotective effects of BMP10 are dependent on the activation of STAT3.

Green approaches for the synthesis of metal and metal oxide nanoparticles using microbial and plant extracts

Green synthesis approaches are gaining significance as promising routes for the sustainable preparation of nanoparticles, offering reduced toxicity towards living organisms and the environment. Nanomaterials produced by green synthesis approaches can offer additional benefits, including reduced energy inputs and lower production costs than traditional synthesis, which bodes well for commercial-scale production. The biomolecules and phytochemicals extracted from microbes and plants, respectively, are active compounds that function as reducing and stabilizing agents for the green synthesis of nanoparticles. Microorganisms, such as bacteria, yeasts, fungi, and algae, have been used in nanomaterials' biological synthesis for some time. Furthermore, the use of plants or plant extracts for metal and metal-based hybrid nanoparticle synthesis represents a novel green synthesis approach that has attracted significant research interest. This review discusses various biosynthesis approaches via microbes and plants for the green preparation of metal and metal oxide nanoparticles and provides insights into the molecular aspects of the synthesis mechanisms and biomedical applications. The use of agriculture waste as a potential bioresource for nanoparticle synthesis and biomedical applications of biosynthesized nanoparticles is also discussed.

Doxorubicin-loaded graphene oxide nanocomposites in cancer medicine: Stimuli-responsive carriers, co-delivery and suppressing resistance

INTRODUCTION

The application of doxorubicin (DOX) in cancer therapy has been limited due to its drug resistance and poor internalization. Graphene oxide (GO) nanostructures have the capacity for DOX delivery while promoting its cytotoxicity in cancer.

AREAS COVERED

The favorable characteristics of GO nanocomposites, preparation method, and application in cancer therapy are described. Then, DOX resistance in cancer is discussed. The GO-mediated photothermal therapy and DOX delivery for cancer suppression are described. Preparation of stimuli-responsive GO nanocomposites, surface functionalization, hybrid nanoparticles, and theranostic applications are emphasized in DOX chemotherapy.

EXPERT OPINION

Graphene oxide nanoparticle-based photothermal therapy maximizes the anti-cancer activity of DOX against cancer cells. Apart from DOX delivery, GO nanomaterials are capable of loading anti-cancer agents and genetic tools to minimize drug resistance and enhance the cytolytic impact of DOX in cancer eradication. To enhance DOX accumulation in cancer cells, stimuli-responsive (redox-, light-, enzyme- and pH-sensitive) GO nanoparticles have been developed for DOX delivery. Further development of targeted delivery of DOX-loaded GO nanomaterials against cancer cells may be achieved by surface modification of polymers such as polyethylene glycol, hyaluronic acid, and chitosan. Doxorubicin-loaded GO nanoparticles have demonstrated theranostic potential for simultaneous diagnosis and therapy. Hybridization of GO with other nanocarriers such as silica and gold nanoparticles further broadens their potential anti-cancer therapy applications.

Clinical application of nano-targeting for enhancing chemotherapeutic efficacy and safety in cancer management

Despite improvements in treatment, cancer remains a leading cause of death worldwide. While chemotherapy is effective, it also damages healthy tissue, leading to severe, dose-limiting side effects that can impair efficacy and even contribute to chemoresistance. Nano-based drug-delivery systems can potentially target the delivery of chemotherapy to improve efficacy and reduce adverse effects. A number of nanocarriers have been investigated for the delivery of chemotherapy, and many of the most promising agents have advanced to clinical trials. This review examines the safety and efficacy of nanoformulated chemotherapeutic agents in clinical trials, with particular emphasis on anthracyclines, taxanes and platinum compounds. It also briefly discusses the role nano-targeting might play in the prevention and treatment of chemoresistance.

Regulation of drug release performance using mixed doxorubicin-doxorubicin dimer nanoparticles as a pH-triggered drug self-delivery system

A mixed drug self-delivery system (DSDS) with high drug content (>50%) was developed to regulate pH-triggered drug release, based on two doxorubicin (DOX)-DOX dimmers: D-DOXADH and D-DOXcar conjugated with acid-labile dynamic covalent bonds (hydrazone and carbamate, respectively) and stabilized with PEGylated D-DOXADH (D-DOXADH-PEG). Owing to the different stability of the dynamic covalent bonds in the two dimers and the noncovalent interaction between them, pH-triggered drug release could be easily regulated by adjusting the feeding ratios of the two DOX-DOX dimers in the mixed DSDS. Similar in vitro cellular toxicity was achieved with the mixed DSDS nanoparticles prepared with different feeding ratios. The mixed DSDS nanoparticles had a similar DOX content and diameter but different drug releasing rates. The MTT assays revealed that a high anti-tumor efficacy could be achieved with the slow-release mixed DSDS nanoparticles.

Redirecting Chemotherapeutics to the Endoplasmic Reticulum Increases Tumor Immunogenicity and Potentiates Anti-PD-L1 Therapy

The endoplasmic reticulum (ER) in cancer cells has been considered as a pharmacological target. Still, the effects of a ER-targeted system remain less investigated, due to the fact that most chemo-drugs take actions in the nucleus. Here, it is demonstrated that ER-targeted delivery of doxorubicin (DOX), a typically nucleus-tropic-and-acting agent, attenuates its original effect on cytotoxicity while generating new functions favorable for immune activation. First, a library of DOX derivatives with variable ER-targeting abilities is synthesized. The results reveal that higher ER-targeting efficiency correlates with greater ER stress. As compared with naïve drug, ER-targeted DOX considerably alters the mode of action from nuclear DNA damage-associated cytotoxicity to ER stress-mediated calreticulin exposure. Consequently, ER-targeted DOX decreases cytotoxicity but increases the capability to induce immunogenic cell death (ICD). Therefore, a platform combining naïve and ER-targeted DOX is constructed for in vivo application. Conventional polymer-DOX conjugate inhibits tumor growth by exerting a direct killing effect, and ER-targeted polymer-DOX conjugate suppresses residual tumors by eliciting ICD-associated immunity, together resulting in considerable tumor regression. In addition, simultaneous inhibition of adaptive PD-L1 enrichment (due to negative-feedback to ICD induction) further leads to greater therapeutic outcome. Collectively, ER-targeted therapy can enhance anticancer efficacy by promoting ICD-associated immunotherapy, and potentiating chemotherapy and checkpoint blockade therapy.

Carbosilane Glycodendrimers for Anticancer Drug Delivery: Synthetic Route, Characterization, and Biological Effect of Glycodendrimer-Doxorubicin Complexes

The complexity of drug delivery mechanisms calls for the development of new transport system designs. Here, we report a robust synthetic procedure toward stable glycodendrimer (glyco-DDM) series bearing glucose, galactose, and oligo(ethylene glycol)-modified galactose peripheral units. In vitro cytotoxicity assays showed exceptional biocompatibility of the glyco-DDMs. To demonstrate applicability in drug delivery, the anticancer agent doxorubicin (DOX) was encapsulated in the glyco-DDM structure. The anticancer activity of the resulting glyco-DDM/DOX complexes was evaluated on the noncancerous (BJ) and cancerous (MCF-7 and A2780) cell lines, revealing their promising generation- and concentration-dependent effect. The glyco-DDM/DOX complexes show gradual and pH-dependent DOX release profiles. Fluorescence spectra elucidated the encapsulation process. Confocal fluorescence microscopy demonstrated preferential cancer cell internalization of the glyco-DDM/DOX complexes. The conclusions were supported by computer modeling. Overall, our results are consistent with the assumption that novel glyco-DDMs and their drug complexes are very promising in drug delivery and related applications.

Polyester Dendrimers Based on Bis-MPA for Doxorubicin Delivery

Although doxorubicin (DOX) is one of the most used chemotherapeutic drugs due to its efficacy against a wide group of cancer types, it presents severe side effects. As such, intensive research is being carried out to find new nanoscale systems that can help to overcome this problem. Polyester dendrimers based on the monomer 2,2-bis(hydroxymethyl)propionic acid (bis-MPA) are very promising systems for biomedical applications due to their biodegradability properties. In this study, bis-MPA-based dendrimers were, for the first time, evaluated as DOX delivery vehicles. Generations 4 and 5 of bis-MPA-based dendrimers with hydroxyl groups at the surface were used (B-G4-OH and B-G5-OH), together with dendrimers partially functionalized with amine groups (B-G4-NH₂/OH and B-G5-NH₂/OH). Partial functionalization was chosen because the main purpose was to compare the effect of different functional groups on dendrimers' drug delivery behavior without compromising cell viability, which is often affected by dendrimers' cationic charge. Results revealed that bis-MPA-based dendrimers were cytocompatible, independently of the chemical groups that were present at their surface. The B-G4-NH₂/OH and B-G5-NH₂/OH dendrimers were able to retain a higher number of DOX molecules, but the in vitro release of the drug was faster. On the contrary, the hydroxyl-terminated dendrimers exhibited a lower loading capacity but were able to deliver the drug in a more sustained manner. These results were in accordance with the cytotoxicity studies performed in several models of cancer cell lines and human mesenchymal stem cells. Overall, the results confirmed that it is possible to tune the drug delivery properties of bis-MPA-based dendrimers by modifying surface functionalization. Moreover, molecular modeling studies provided insights into the nature of the interactions established between the drug and the bis-MPA-based dendrimers─DOX molecules attach to their surface rather than being physically encapsulated.

Green approaches for the synthesis of metal and metal oxide nanoparticles using microbial and plant extracts

Green synthesis approaches are gaining significance as promising routes for the sustainable preparation of nanoparticles, offering reduced toxicity towards living organisms and the environment.

Thermosensitive hydrogel-functionalized gold nanorod/mesoporous MnO2 nanoparticles for tumor cell-triggered drug delivery

MnO₂ owns distinct redox, imaging, and degradable properties corresponding to the tumor microenvironment. However, the onefold structure and non-modifiable property cause many obstacles to anticancer applications. In this report, we first prepared a typical core-shell gold nanorod (GNR)/manganese dioxide (MnO₂) nanoparticles (GNR/MnO₂ NPs). Interestingly, the MnO₂ had a mesoporous channel and modifiable hydroxyl group (OH). Here, the unique 'OH' groups were modified and further grafted with poly(N-isopropylacrylamide-co-acrylic acid) (PNA). As a dual-sensitive hydrogel, it was selected as the thermal/pH-sensitive component in the hybrid nanoparticles (GNR/MnO₂/PNA NPs). The anticancer drug doxorubicin hydrochloride (DOX) was selected and loaded into the hybrid nanoparticles (GNR/MnO₂/PNA-DOX NPs). The GNR/MnO₂/PNA NPs achieved satisfying drug-loading efficiency and glutathione (GSH)/pH/thermal-responsive drug-controlled release. As a side benefit, the GNR/MnO₂/PNA NPs showed potential as excellent near-infrared (NIR)-excited nanoplatforms for photothermal therapy (PTT). Delightedly, the studies demonstrated that the GNR/MnO₂/PNA-DOX NPs showed a noticeable killing effect on tumor cells, whether it is tumor cell-triggered drug release or photothermal effect. Besides, it not only could enhance mitochondrial damage but also could inhibit the migration and invasion of tumor cells. Quite the reverse, it had little negative impact on normal cells. The feature can prevent anticancer drugs and nanoparticles from killing normal cells. Consequently, GNR/MnO₂/PNA NPs have potential applications in drug delivery and synergistic therapy due to these advantageous features.

Ultrasound Molecular Imaging for the Guidance of Ultrasound-Triggered Release of Liposomal Doxorubicin and Its Treatment Monitoring in an Orthotopic Prostatic Tumor Model in Rat

Liposome encapsulation of drugs is an interesting approach in cancer therapy to specifically release the encapsulated drug at the desired treatment site. In addition to thermo-, pH-, light-, enzyme- or redox-responsive liposomes, which have had promising results in (pre-) clinical studies, ultrasound-triggered sonosensitive liposomes represent an exciting alternative to locally trigger the release from these cargos. Localized drug release requires precise tumor visualization to produce a targeted and ultrasound stimulus. We used ultrasound molecular imaging (USMI) with BR55, a vascular endothelial growth factor receptor 2 (VEGFR2)-targeted ultrasound contrast agent, to guide ultrasound-triggered release of sonosensitive liposomes encapsulating doxorubicin (L-DXR) in an orthotopic prostatic rodent tumor model. Forty-eight hours after L-DXR injection, local release of doxorubicin was triggered with a confocal ultrasound device with two focused transducers, 1.1-MHz center frequency, and peak positive and negative pressures of 20.5 and 13 MPa at focus. Tumor size decreased by 20% in 2 wk with L-DXR alone (n = 9) and by 70% after treatment with L-DXR and confocal ultrasound (n = 7) (p < 0.01). The effect of doxorubicin on perfusion/vascularity and VEGFR2 expression was evaluated by USMI and immunohistochemistry of CD31 and VEGFR2 and did not reveal differences in perfusion or VEGFR2 expression in the absence or after the triggered release of liposomes. USMI can provide precise guidance for ultrasound-triggered release of liposomal doxorubicin mediated by a confocal ultrasound device; moreover, the combination of B-mode imaging and USMI can help to follow the response of the tumor to the therapy.

Research progress in strategies to improve the efficacy and safety of doxorubicin for cancer chemotherapy

INTRODUCTION

DOX exerts strong anticancer activity and is commonly used to treat different cancers, including bone sarcomas, soft tissues, bladder, ovary, stomach, thyroid, breast, acute lymphoblastic leukemia, Hodgkin lymphoma, lung cancer, and myeloblastic leukemia. However, the cumulative doses of DOX above 550mg/m2 cause irreversible cardiotoxicity and other severe adverse effects. In this context, concerning DOX, several patents have been published in the last two decades. This activity highlights various aspects of DOX, such as registered patent analysis, pharmacological action, toxicityminimization, formulation development such as those approved by FDA, under clinical trials, and newly developed nano-delivery systems.

AREAS COVERED

This review analyzes the different aspects of DOX-based chemotherapeutics and the development of drug delivery systems in theliterature published from 2000 to early 2020.

EXPERT OPINION

DOX-based chemotherapy is still few steps away from being "perfect and safe" therapy. Certain severe systemic side effects are associated with DOX therapy. It is expected that, in the near future, DOX therapy can be much effective by selecting an ideal nanocarrier system, DOX conjugates, proper structural modifications, DOX-immunotherapy, and combination therapy. The advanced formulationsof DOX from the registered patents and recent research articles need clinical trials to bring safe treatment for cancer patients.

Polysaccharide-based nanomedicines for cancer immunotherapy: A review

Cancer immunotherapy is an effective antitumor approach through activating immune systems to eradicate tumors by immunotherapeutics. However, direct administration of "naked" immunotherapeutic agents (such as nucleic acids, cytokines, adjuvants or antigens without delivery vehicles) often results in: (1) an unsatisfactory efficacy due to suboptimal pharmacokinetics; (2) strong toxic and side effects due to low targeting (or off-target) efficiency. To overcome these shortcomings, a series of polysaccharide-based nanoparticles have been developed to carry immunotherapeutics to enhance antitumor immune responses with reduced toxicity and side effects. Polysaccharides are a family of natural polymers that hold unique physicochemical and biological properties, as they could interact with immune system to stimulate an enhanced immune response. Their structures offer versatility in synthesizing multifunctional nanocomposites, which could be chemically modified to achieve high stability and bioavailability for delivering therapeutics into tumor tissues. This review aims to highlight recent advances in polysaccharide-based nanomedicines for cancer immunotherapy and propose new perspectives on the use of polysaccharide-based immunotherapeutics.

A Screening Study for the Development of Simvastatin-Doxorubicin Liposomes, a Co-Formulation with Future Perspectives in Colon Cancer Therapy

An increasing number of studies published so far have evidenced the benefits of Simvastatin (SIM) and Doxorubicin (DOX) co-treatment in colorectal cancer. In view of this, the current study aimed to investigate the pharmaceutical development of liposomes co-encapsulating SIM and DOX, by implementing the Quality by Design (QbD) concept, as a means to enhance the antiproliferative effect of the co-formulation on C26 murine colon cancer cells co-cultured with macrophages. It is known that the quality profile of liposomes is dependent on the critical quality attributes (CQAs) of liposomes (drug entrapped concentration, encapsulation efficiency, size, zeta potential, and drug release profile), which are, in turn, directly influenced by various formulation factors and processing parameters. By using the design of experiments, it was possible to outline the increased variability of CQAs in relation to formulation factors and identify by means of statistical analysis the material attributes that are critical (phospholipids, DOX and SIM concentration) for the quality of the co-formulation. The in vitro studies performed on a murine colon cancer cell line highlighted the importance of delivering the optimal drug ratio at the target site, since the balance antiproliferative vs. pro-proliferative effects can easily be shifted when the molar ratio between DOX and SIM changes.

Solid Lipid Nanoparticles (SLNs): An Advanced Drug Delivery System Targeting Brain through BBB

The blood-brain barrier (BBB) plays a vital role in the protection and maintenance of homeostasis in the brain. In this way, it is an interesting target as an interface for various types of drug delivery, specifically in the context of the treatment of several neuropathological conditions where the therapeutic agents cannot cross the BBB. Drug toxicity and on-target specificity are among some of the limitations associated with current neurotherapeutics. In recent years, advances in nanodrug delivery have enabled the carrier system containing the active therapeutic drug to target the signaling pathways and pathophysiology that are closely linked to central nervous system (CNS) disorders such as Alzheimer's disease (AD), Parkinson's disease (PD), Huntington's disease (HD), multiple sclerosis (MS), brain tumor, epilepsy, ischemic stroke, and neurodegeneration. At present, among the nano formulations, solid lipid nanoparticles (SLNs) have emerged as a putative drug carrier system that can deliver the active therapeutics (drug-loaded SLNs) across the BBB at the target site of the brain, offering a novel approach with controlled drug delivery, longer circulation time, target specificity, and higher efficacy, and more importantly, reducing toxicity in a biomimetic way. This paper highlights the synthesis and application of SLNs as a novel nontoxic formulation strategy to carry CNS drugs across the BBB to improve the use of therapeutics agents in treating major neurological disorders in future clinics.

Doxorubicin Loaded Dextran-coated Superparamagnetic Iron Oxide Nanoparticles with Sustained Release Property: Intracellular Uptake, Pharmacokinetics, and Biodistribution Study

BACKGROUND

Due to the short biological half-life and serious side effects (especially for heart and kidney), the application of Doxorubicin (Dox) in clinical therapy is strictly limited. To overcome these shortcomings, a novel sustained release formulation of doxorubicin-loaded dextran-coated superparamagnetic iron oxide nanoparticles (Dox-DSPIONs) was prepared.

OBJECTIVE

The purpose of this study was to evaluate the intracellular uptake behavior of Dox-DSPIONs and to investigate their pharmacokinetics and biodistribution properties.

METHOD

Confocal laser scanning microscopy was employed to study the intracellular uptake and release properties of Dox from Dox-DSPIONs in SMMC-7721 cells. Simple high-performance liquid chromatography with fluorescence detection (HPLC-FLD) method was established to study the pharmacokinetics and biodistribution properties of Dox-DSPIONs in vivo after intravenous administration and compared with free Dox.

RESULTS

Intracellular uptake experiment indicated that Dox could be released sustainedly from Dox-DSPIONs over time. The pharmacokinetics parameters displayed that the T1/2and AUC0-24h of Dox-DSPIONs were higher than those of free Dox, while the Cmax of Dox-DSPIONs was significantly lower than that of free drug. The biodistribution behaviors of the drug were altered by Dox-DSPIONs in mice, which showed obvious liver targeting, and significantly reduced the distribution of the drug in the heart and kidney.

CONCLUSION

Dox-DSPIONs have the sustained-release property in vitro and in vivo, which could significantly prolong blood circulation time, improve bioavailability, and reduce the side effects of Dox. Therefore, the novel formulation of the Dox-DSPIONs has the potential as a promising drug delivery system in cancer therapy.

An update on actively targeted liposomes in advanced drug delivery to glioma

High-grade glioma is one of the most aggressive types of cancer with a low survival rate ranging from 12 to 15 months after the first diagnosis. Though being the most common strategy for glioma therapy, conventional chemotherapy suffers providing the therapeutic dosage of common therapeutics mostly because of limited permeability of blood-brain barrier (BBB), and blood-brain tumor barrier (BBTB) to anticancer agents. Among various nanoformulations, liposomes are considered as the most popular carriers aimed for glioma therapy. However, non-targeted liposomes which passively accumulate in most of the cancer tissues mainly through the enhanced permeation and retention effect (EPR), may not be applicable for glioma therapy due to BBB tight junctions. In the recent decade, the surface modification of liposomes with different active targeting ligands has shown promising results by getting different chemotherapeutics across the BBB and BBTB and leading them into the glioma cells. The present review discusses the major barriers for drug delivery systems to glioma, elaborates the existing mechanisms for liposomes to traverse across the BBB, and explores the main strategies for incorporation of targeting ligands onto the liposomes. It subsequently investigates the most recent and relevant studies of actively targeted liposomes modified with antibodies, aptamers, monosaccharides, polysaccharides, proteins, and peptides applied for effective glioma therapy, and highlights the common challenges facing this area. Finally, the actively targeted liposomes undergoing preclinical and clinical studies for delivery of different anticancer agents to glioma cells will be reviewed.

Cancer Nanopharmaceuticals: Physicochemical Characterization and In Vitro/In Vivo Applications

Physicochemical, pharmacokinetic, and biopharmaceutical characterization tools play a key role in the assessment of nanopharmaceuticals' potential imaging analysis and for site-specific delivery of anti-cancers to neoplastic cells/tissues. If diagnostic tools and therapeutic approaches are combined in one single nanoparticle, a new platform called nanotheragnostics is generated. Several analytical technologies allow us to characterize nanopharmaceuticals and nanoparticles and their properties so that they can be properly used in cancer therapy. This paper describes the role of multifunctional nanoparticles in cancer diagnosis and treatment, describing how nanotheragnostics can be useful in modern chemotherapy, and finally, the challenges associated with the commercialization of nanoparticles for cancer therapy.

Albumin nanoformulations as an innovative solution to overcome doxorubicin chemoresistance

Aim: Resistance to chemotherapy is a major limiting factor that hamper the effectiveness of anticancer therapies. Doxorubicin is an antineoplastic agent used in the treatment of a wide range of cancers. However, it presents several limitations such as dose-dependent cardiotoxicity, lack of selectivity for tumor cells, and induced cell resistance. Nanotechnology represents a promising strategy to avoid these drawbacks. In this work, new albumin-based nanoparticles were formulated for the intracellular delivery of doxorubicin with the aim to overcome cancer drug resistance.

Methods: Glycol chitosan-coated and uncoated albumin nanoparticles were prepared with a tuned coacervation method. The nanoformulations were in vitro characterized evaluating the physicochemical parameters, morphology, and in vitro release kinetics. Biological assays were performed on A2780res and EMT6 cells from human ovarian carcinoma and mouse mammary cell lines resistant for doxorubicin, respectively.

Results: Cell viability assays showed that nanoparticles have higher cytotoxicity than the free drug. Moreover, at low concentrations, both doxorubicin-loaded nanoparticles inhibited the cell colony formation in a greater extent than drug solution. In addition, the cell uptake of the different formulations was investigated by confocal microscopy and by the HPLC determination of doxorubicin intracellular accumulation. The nanoparticles were rapidly internalized in greater extent compared to the free drug.

Conclusion: Based on these results, doxorubicin-loaded albumin nanoparticles might represent a novel platform to overcome the mechanism of drug resistance in cancer cell lines and improve the drug efficacy.

Synthesis, Characterization, Cellular Uptake, and In Vitro Anticancer Activity of Fullerenol-Doxorubicin Conjugates

Doxorubicin (DOX) is one of the most commonly used chemotherapeutic agents for treating human cancer. However, its clinical use has been limited by DOX-induced cardiotoxicity as well as other side effects. In the present study, we designed and synthesized the fullerenol (FU)-DOX conjugates and folic acid (FA)-grafted FU-DOX conjugates for improving the selectivity and activity of DOX in cancer cells. We further characterized the physicochemical properties and examined the release kinetics, cellular uptake, and in vitro anticancer activities of FU-DOX and FA-FU-DOX. The results showed that FU-DOX and FA-FU-DOX had a mean diameter of <200 nm and a low polydispersity. Both FU-DOX and FA-FU-DOX exhibited pH sensitivity and their DOX release rates were higher at pH 5.9 vs. pH 7.4. The cellular uptake studies indicated that FU conjugation enhanced the intracellular accumulation of DOX in human hepatocellular carcinoma (HCC) cell lines (BEL-7402 and HepG2) and the immortalized normal human hepatocytes (L02). The conjugation of FA to FU-DOX further promoted the drug internalization in an FR-dependent manner and enhanced the cytotoxicity against HCC cells. In conclusion, the newly prepared FA-FU-DOX conjugates can optimize the safety and efficacy profile of DOX.

Adriamycin-resistant cells are significantly less fit than adriamycin-sensitive cells in cervical cancer

Adriamycin (ADR) is an important chemotherapy agent in many advanced cancers, but the emergence of drug resistance during treatment is a major limitation to its successful use. Recent studies have suggested that drug-resistant cells become less fit and their growth could be inhibited by parental cells without cytotoxic treatment. In this study, we examined the fitness differences between HeLa and HeLa/ADR cells. Compared with the parental cell line, HeLa/ADR cells showed significantly lower growth rates, both in vitro and in vivo. There was no difference in the apoptosis rate between them, but G1 arrest and reduced DNA synthesis were found in HeLa/ADR cells. Further study indicated that HeLa/ADR cells failed to compete for space and nutrition against parental cells in vivo. Taken together, we demonstrate that HeLa/ADR cells are less fit and their growth can be inhibited by parental cells in the absence of ADR; therefore, the maintenance of a certain amount of ADR-sensitive cells during treatment may facilitate the control of the development of ADR resistance.

Nanocarriers for drug delivery to the inner ear: Physicochemical key parameters, biodistribution, safety and efficacy

Despite the high incidence of inner ear disorders, there are still no dedicated medications on the market. Drugs are currently administered by the intratympanic route, the safest way to maximize drug concentration in the inner ear. Nevertheless, therapeutic doses are ensured for only a few minutes/hours using drug solutions or suspensions. The passage through the middle ear barrier strongly depends on drug physicochemical characteristics. For the past 15 years, drug encapsulation into nanocarriers has been developed to overcome this drawback. Nanocarriers are well known to sustain drug release and protect it from degradation. In this review, in vivo studies are detailed concerning nanocarrier biodistribution, their pathway mechanisms in the inner ear and the resulting drug pharmacokinetics. Key parameters influencing nanocarrier biodistribution are identified and discussed: nanocarrier size, concentration, surface composition and shape. Recent advanced strategies that combine nanocarriers with hydrogels, specific tissue targeting or modification of the round window permeability (cell-penetrating peptide, magnetic delivery) are explored. Most of the nanocarriers appear to be safe for the inner ear and provide a significant efficacy over classic formulations in animal models. However, many challenges remain to be overcome for future clinical applications.

Timeline of Translational Formulation Technologies for Cancer Therapy: Successes, Failures, and Lessons Learned Therefrom

Over the past few decades, the field of cancer therapy has seen a significant change in the way in which formulations are designed and developed, resulting in more efficient products that allow us to ultimately achieve improved drug bioavailability, efficacy, and safety. However, although many formulations have entered the market, many others have fallen by the wayside leaving the scientific community with several lessons to learn. The successes (and failures) achieved with formulations that have been approved in Europe and/or by the FDA for the three major types of cancer therapy (peptide-based therapy, chemotherapy, and radiotherapy) are reviewed herein, covering the period from the approval of the first prolonged-release system for hormonal therapy to the appearance of the first biodegradable microspheres intended for chemoembolization in 2020. In addition, those products that have entered phase III clinical trials that have been active over the last five years are summarized in order to outline future research trends and possibilities that lie ahead to develop clinically translatable formulations for cancer treatment.

Advances and trends of hydrogel therapy platform in localized tumor treatment: A review

Due to limitations of treatment and the stubbornness of infiltrative tumor cells, the outcome of conventional antitumor treatment is often compromised by a variety of factors, including severe side effects, unexpected recurrence, and massive tissue loss during the treatment. Hydrogel-based therapy is becoming a promising option of cancer treatment, because of its controllability, biocompatibility, high drug loading, prolonged drug release, and specific stimuli-sensitivity. Hydrogel-based therapy has good malleability and can reach some areas that cannot be easily touched by surgeons. Furthermore, hydrogel can be used not only as a carrier for tumor treatment agents, but also as a scaffold for tissue repair. In this review, we presented the latest researches in hydrogel applications of localized tumor therapy and highlighted the recent progress of hydrogel-based therapy in preventing postoperative tumor recurrence and improving tissue repair, thus proposing a new trend of hydrogel-based technology in localized tumor therapy. And this review aims to provide a novel reference and inspire thoughts for a more accurate and individualized cancer treatment.

Olmutinib Reverses Doxorubicin Resistance in ETS1-Overexpressing Leukemia Cells

BACKGROUND Drug resistance is a major problem in the treatment of leukemia with doxorubicin (Dox), and the erythroblastosis virus E26 oncogene homolog 1 (ETS1) gene is associated with drug resistance. Olmutinib is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) reported to play a role in reversing multidrug resistance (MDR) in cancer cells. The objective of this study was to investigate whether olmutinib could reverse Dox resistance in leukemia cells overexpressing ETS1. MATERIAL AND METHODS Human chronic myelogenous leukemia cell line K562 and its Dox-resistant cell line K562/ADR were used. Western blot and qPCR detected the expression of ETS1 and ABCB1. Cell proliferation was measured by cell counting kit-8 and methyl thiazolyl tetrazolium. Cell apoptosis was observed by western blot and flow cytometry. A nude mice K562/ADR xenograft model was used to investigate the inhibitory effects of olmutinib on tumor growth in vivo. RESULTS The mRNA and protein expressions of ETS1 and ABCB1 were up-regulated in Dox-resistant leukemia cell line K562/ADR. We overexpressed ETS1 in both cell lines, finding that olmutinib inhibited the cell viability of K562 and K562/ADR in a concentration-dependent manner. The cytotoxicity of Dox to EST1-overexpressing K562/ADR cells was enhanced by olmutinib. Olmutinib also promoted apoptosis of K562 and K562/ADR cells compared with Dox treatment alone. In vivo, olmutinib enhanced the inhibitory effects of Dox on ETS1-overexpressing K562/ADR cell xenograft growth. CONCLUSIONS Our results suggest that the novel EGFR TKI olmutinib enhances the sensitivity of ETS1-overexpressing leukemia cells to Dox.