Gemcitabine and tamoxifen-loaded liposomes as multidrug carriers for the treatment of breast cancer diseases

Tretinoin (2,4-difluoro-phenyl) triazole activates proapoptotic protein expression and targets NRP2 protein to inhibit esophageal carcinoma cell growth

The present study investigated the effect of tretinoin (2,4-difluoro-phenyl) triazole (TDFPT) on the growth and proliferation of Kyse-270 and EC9706 esophageal carcinoma cells and explored the underlying mechanism. The results demonstrated that TDFPT treatment of Kyse-270 and EC9706 cells led to a dose-dependent reduction in cell proliferation. Colony formation was significantly (p < .05) reduced in Kyse-270 and EC9706 cells on treatment with various concentrations of TDFPT. In TDFPT-treated Kyse-270 and EC9706 cells, the expression of Bcl-2 protein showed a remarkable decrease, whereas the level of Bax protein was found to be higher compared with the control cells. Cell invasion showed a prominent decrease in Kyse-270 and EC9706 cells on treatment with TDFPT. Treatment with TDFPT led to a prominent suppression in the expression of MMP-9 and NRP2 in Kyse-270 and EC9706 cells. In silico studies using the AutoDock Vina and discovery studio software revealed that various confirmations of TDFPT bind to NRP2 protein with the affinity ranging from -8.6 to -6.1 kcal/mol. It was found that the TDFPT interacts with NRP2 protein by binding to alanine (ALA A:295), proline (PRO A:306), glutamine (GLN A:307), and isoleucine (ILE A:293) amino acid residues. In summary, TDFPT exposure suppresses esophageal carcinoma cell proliferation, inhibits colony formation ability, and activates apoptotic pathway. Thus, TDFPT acts as an effective antiproliferative agent for esophageal carcinoma cells and needs to be investigated further as chemotherapeutic molecule.

Nanomedicine in therapeutic warfront against estrogen receptor-positive breast cancer

Breast cancer (BC) is the most frequently diagnosed malignancy in women worldwide. Almost 70-80% of cases of BC are curable at the early non-metastatic stage. BC is a heterogeneous disease with different molecular subtypes. Around 70% of breast tumors exhibit estrogen-receptor (ER) expression and endocrine therapy is used for the treatment of these patients. However, there are high chances of recurrence in the endocrine therapy regimen. Though chemotherapy and radiation therapy have substantially improved survival rates and treatment outcomes in BC patients, there is an increased possibility of the development of resistance and dose-limiting toxicities. Conventional treatment approaches often suffer from low bioavailability, adverse effects due to the non-specific action of chemotherapeutics, and low antitumor efficacy. Nanomedicine has emerged as a conspicuous strategy for delivering anticancer therapeutics in BC management. It has revolutionized the area of cancer therapy by increasing the bioavailability of the therapeutics and improving their anticancer efficacy with reduced toxicities on healthy tissues. In this article, we have highlighted various mechanisms and pathways involved in the progression of ER-positive BC. Further, different nanocarriers delivering drugs, genes, and natural therapeutic agents for surmounting BC are the spotlights of this article.

Radiolabeled gemcitabine hydrochloride as an imaging agent for lung cancer: Radiolabeling, quality control and cell incorporation studies

The development of new drugs that can specifically screen tumors is a global need. When it comes to lung cancer, which is the second main cause of cancer-related deaths, early detection of lung tumors using appropriate imaging is very important. In this study, gemcitabine hydrochloride (GCH) was radiolabeled with [^99mTc]Tc under different conditions (changing reducing agent, antioxidant agent, incubation time, pH, [^99mTc]Tc activity) and radiolabeling activity (quality control) using Radio Thin Layer Chromatography and paper electrophoresis. The results showed that the most stable complex ([^99mTc]Tc-GCH) was prepared using 0.015 mg of stannous chloride as a reducing agent, 0.01 mg of ascorbic acid as an antioxidant and 37 MBq activity at pH 7.4 after 15 min of incubation time. The complex remained stable for 6 h. Cell incorporation studies showed a six-fold higher uptake of [^99mTc]Tc-GCH in cancer (A-549) cells (38.42 ± 1.53) than healthy (L-929) cells (6.11 ± 0.17) have shown that it can. In addition, the different behaviors of R/H-[^99mTc]Tc confirmed the specificity of this newly developed radiopharmaceutical. Although these studies are preliminary, it has been concluded that [^99mTc]Tc-GCH may be a candidate drug for use in nuclear medicine, particularly in the diagnosis of lung cancer.

Organic Nanodelivery Systems as a New Platform in the Management of Breast Cancer: A Comprehensive Review from Preclinical to Clinical Studies

Breast cancer accounts for approximately 25% of cancer cases and 16.5% of cancer deaths in women, and the World Health Organization predicts that the number of new cases will increase by almost 70% over the next two decades, mainly due to an ageing population. Effective diagnostic and treatment strategies are, therefore, urgently required for improving cure rates among patients since current therapeutic modalities have many limitations and side effects. Nanomedicine is evolving as a promising approach for cancer management, including breast cancer, and various types of organic and inorganic nanomaterials have been investigated for their role in breast cancer diagnosis and treatment. Following an overview on breast cancer characteristics and pathogenesis and challenges of the current treatment strategies, the therapeutic potential of biocompatible organic-based nanoparticles such as liposomes and polymeric micelles that have been tested in breast cancer models are reviewed. The efficacies of different drug delivery and targeting strategies are documented, ranging from synthetic to cell-derived nanoformulations together with a summary of the interaction of nanoparticles with externally applied energy such as radiotherapy. The clinical translation of nanoformulations for breast cancer treatment is summarized including those undergoing clinical trials.

Exploration of hemocompatibility and intratumoral accumulation of paclitaxel after loco-regional administration of thermoresponsive hydrogel composed of poloxamer and xanthan gum: An application to dose-dense chemotherapy

Although paclitaxel is a front-line chemotherapeutic agent for the treatment of metastatic breast cancer, its intravenous therapy produces deleterious adverse effects. In an attempt to address the issue, the present study aimed to develop a paclitaxel loaded thermosensitive/thermoresponsive hydrogel (PTXNp-TGel) for loco-regional administration to breast tumors to provide dose-dense chemotherapy. Poloxamer and xanthan gum were used to prepare TGel by the cold method. In vitro and in vivo performance of PTXNp-TGel was compared with TGel, pure drug loaded TGel (PTX-TGel) and marketed formulation, Taxol®. The formulated PTXNp-TGel showed acceptable gelation temperature and time (37 °C and 57 s), lower viscosity at room temperature and higher viscosity at body temperature to support sol-gel transition with increasing temperature, and sustained drug release up to 21 days. Additionally, PTXNp-TGel showed negligible hemolytic toxicity as compared to PTX-TGel and Taxol®. Intratumoral administration of PTXNp-TGel produced significantly higher antitumor activity as indicated by lowest relative tumor volume (1.50) and relative antitumor proliferation rate (27.71 %) in comparison with PTX-TGel, Taxol®, and PTXNp (p < 0.05). Finally, insignificant body weight loss during the experimental period, lack of hematotoxicity, nephrotoxicity, and hepatotoxicity imply improved therapeutic performance of the locally administrated dose-dense therapy of PTXNp-TGel as compared to Taxol®.

Co-delivery of gemcitabine and salinomycin in PEGylated liposomes for enhanced anticancer efficacy against colorectal cancer

Colorectal cancer remains one of the major causes of morbidity and mortality in both developed and emerging countries. Cancer stem cells (CSCs) are a subpopulation of cells within the tumor mass harboring stem cell characteristics, considered responsible for tumor initiation, growth, relapse, and treatment failure. Lately, it has become clear that both CSCs and non-CSCs have to be eliminated for the successful eradication of cancer. Drug delivery systems have been extensively employed to enhance drug efficacy. In this study, salinomycin (SAL), a selective anti-CSC drug, and gemcitabine (GEM), a conventional anticancer drug, were co-loaded in liposomes and tested for optimal therapeutic efficacy. We employed the Design of Experiments approach to develop and optimize a liposomal delivery system for GEM and SAL. The antiproliferative effect of the liposomes was evaluated in SW-620 human colorectal cancer cells. The GEM and SAL-loaded liposomes exhibited adequate size, polydispersity, zeta potential, and drug content. The in vitro release study showed a sustained release of GEM and SAL from the liposomes over 72 h. Moreover, no sign of liposome aggregation was seen over 1 month and in a biological medium (FBS). The in vitro cytotoxic effects of the co-loaded liposomes were superior to that of single GEM either in free or liposomal form. The combination therapy using GEM and SAL co-loaded in liposomes could be a promising strategy for tackling colorectal cancer.

Lipid nano-vesicles for thyroid hormone encapsulation: A comparison between different fabrication technologies, drug loading, and an in vitro delivery to human tendon stem/progenitor cells in 2D and 3D culture

Phosphatidylcholine (PC) vesicles loaded with Triiodothyronine (T3) were fabricated using different manufacturing methods: thin layer hydration plus sonication (TF-UF), supercritical liposome formation (SC), and microfluidic technology (MF). Vesicles obtained by MF had the lowest mean diameter (88.61 ± 44.48 nm) with a Zeta Potential of -20.1 ± 5.90 mV and loading of 10 mg/g (encapsulation efficiency: 57%). In contrast, SC vesicles showed extremely low encapsulation efficiency (<10%) probably due to T3 solubility in ethanol/carbon dioxide mixture; despite TF-UF vesicles exhibiting good size (167.7 ± 90 nm; Zp -8.50 ± 0.60 mV) and loading (10 mg/g), poor mass recovery was obtained (50% loss). MF vesicles had low cytotoxicity, and they were well enough internalized by both HeLa and human tendon stem/progenitor cells (hTSPCs). Their biological activity was also monitored in both 2D and 3D cultures of hTSPCs supplemented with therapeutical concentrations of PC/T3 nano-liposomes. 2D culture showed almost similar constitutive gene expression compared to control culture supplemented with free-T3. On the contrary, when hTPSCs 3D culture was assembled, it showed a more evident homogeneous distribution of FITC labeled vesicles within the high-density structure and a significant upregulation of cell constitutive genes, such as type I Collagen (4.8-fold; p < 0.0001) at day 7, compared to the control, suggesting that T3/PC formulation has increased T3 cytosolic concentration, thus improving cells metabolic activity. The study supported MF technology for nano-carriers fabrication and opens perspectives on the activity of PC/T3 nano-vesicles as innovative formulations for TPSCs stimulation in ECM secretion.

Injectable hydrogel loaded with paclitaxel and epirubicin to prevent postoperative recurrence and metastasis of breast cancer

Post-operative recurrence and metastasis is a major challenge for breast cancer treatment. Local chemotherapy is a promising strategy that can overcome this problem. In this study, we synthesized an injectable hyaluronic acid (HA)-based hydrogel loaded with paclitaxel (PTX) nanoparticles and epirubicin (EPB) (PPNPs/EPB@HA-Gel). PPNPs/EPB@HA-Gel steadily released the encapsulated drugs to achieve long-term inhibition of tumor recurrence and metastasis in a murine post-operative breast tumor model, which prolonged their survival without any systemic toxicity. The drug-loaded hydrogel inhibited the proliferation and migration of tumor cells in vitro, and significantly increased tumor cell apoptosis in vivo. Therefore, PPNPs/EPB@HA-Gel can be used as a local chemotherapeutic agent to prevent postoperative recurrence and metastasis of breast cancer.

Development of polyoxyethylene (2) oleyl ether-gliadin nanoparticles: Characterization and in vitro cytotoxicity

Natural polymers have been widely investigated as materials for the delivery of active compounds as a consequence of their biocompatibility, low-cost and the opportunity they furnish to obtain micro- and nanostructures. In this investigation, commercial wheat gliadin was used as raw material with the aim of obtaining a vegetal protein-based nanoformulation to be used for various applications. The influence of non-ionic and anionic surfactants on the physico-chemical properties of gliadin nanoparticles was evaluated in order to propose a suitable candidate able to stabilize the colloidal structure. The use of Super Refined polyoxyethylene (2) oleyl ether gave the best results, promoting the formation of spherical-shaped nanosystems with a narrow size distribution. The oleyl ether-based emulsifier prevented the destabilization of the colloidal systems when pH- and temperature-dependent stress was applied. A freeze-dried formulation was obtained when mannose was used as a cryoprotectant. Polyoxyethylene (2) oleyl ether-stabilized nanosystems were shown to retain and release both hydrophilic and lipophilic model compounds in a controlled manner. The cytotoxicity of the surfactant-free and polyoxyethylene (2) oleyl ether-stabilized gliadin based nanosystems was assessed on human cells, both normal and tumoural, in order to investigate the concentrations of particles that can be used during in vitro experiments. Polyoxyethylene (2) oleyl ether-stabilized gliadin-based nanosystems are promising carriers for the delivery of several active compounds.

Recent Advances of Taxol-Loaded Biocompatible Nanocarriers Embedded in Natural Polymer-Based Hydrogels

The discovery of paclitaxel (PTX) has been a milestone in anti-cancer therapy and has promoted the development and marketing of various formulations that have revolutionized the therapeutic approach towards several malignancies. Despite its peculiar anti-cancer activity, the physico-chemical properties of PTX compromise the administration of the compound in polar media. Because of this, since the development of the first Food and Drug Administration (FDA)-approved formulation (Taxol®), consistent efforts have been made to obtain suitable delivery systems able to preserve/increase PTX efficacy and to overcome the side effects correlated to the presence of some excipients. The exploitation of natural polymers as potential materials for drug delivery purposes has favored the modulation of the bioavailability and the pharmacokinetic profiles of the drug, and in this regard, several formulations have been developed that allow the controlled release of the active compound. In this mini-review, the recent advances concerning the design and applications of natural polymer-based hydrogels containing PTX-loaded biocompatible nanocarriers are discussed. The technological features of these formulations as well as the therapeutic outcome achieved following their administration will be described, demonstrating their potential role as innovative systems to be used in anti-tumor therapy.

Surface-engineered nanostructured lipid carrier systems for synergistic combination oncotherapy of non-small cell lung cancer

Nanoparticle-aided combination chemotherapy offers several advantages like ratiometric drug delivery, dose reduction, multi-targeted therapy, synergism, and overcoming multi-drug resistance. The current research was instigated to facilitate targeted and ratiometric co-delivery of docetaxel (DT) and curcumin (CR) through the development of folate (FA)-appended nanostructured lipid carriers (NLCs), i.e., FA-DTCR-NLCs to lung cancer cells. The FA-DTCR-NLCs were formulated by employing a scaleable and solvent-free high-pressure homogenization approach. The FA-DTCR-NLCs were evaluated for in vitro and in vivo characteristics using suitable analytical and statistical techniques. The FA-DTCR-NLCs demonstrated physicochemical properties and particokinetics suitable for targeted, ratiometric co-delivery of the anticancer agents. This was further affirmed by significantly better in vivo relative bioavailability of DT (24.85 fold) with FA-DTCR-NLCs as compared with Taxotere^® (p < 0.05) and cell line studies. A significant tumor regression was observed from the results of tumor staging in a murine model of lung carcinoma (p < 0.05). Immunostaining of the tumor sections with tumor differentiation biomarkers suggested considerably higher apoptotic, anti-proliferative, anti-angiogenic, and anti-metastatic potential of FA-DTCR-NLCs compared with Taxotere^®. In vivo toxicity assessment of the FA-DTCR-NLCs demonstrated a noteworthy reduction in DT associated side effects. The in vitro and in vivo pre-clinical findings prove the therapeutic and safety pre-eminence of FA-DTCR-NLCs for the treatment of NSCLC.

In Vitro Cytotoxicity and Cellular Uptake of Tamoxifen Citrate-Loaded Polymeric Micelles

The main intent of this treatise was to encapsulate tamoxifen citrate (TMXC) into polymeric micellar delivery system and evaluate the influence of TMXC-loaded micelles as a promising carrier on the in vitro cytotoxicity and cellular uptake of TMXC in treatment of breast cancer. Different formulae of polymeric micelles loaded with TMXC using mixtures of different Pluronic polymers were fabricated by thin-film hydration method and evaluated for morphology, drug entrapment efficiency, particle size, surface charge, in vitro liberation of TMXC, uptake by cancer cell lines, and cytotoxic effect against breast cancer cell lines such as MCF-7. The optimal TMXC-loaded micelles exhibited nano-sized particles and entrapped about 89.09 ± 4.2% of TMXC. In vitro liberation study revealed an extended TMXC escape of about 70.23 ± 5.9% over a period of 36 h. The optimized TMXC-loaded micelles formula showed enhanced cellular uptake of TMXC by 2.28 folds and showed a significant cytotoxic effect with MCF-7 breast cancer cells compared to TMXC solution. The obtained yield proposed that Pluronic micelles could be a promising potential delivery system for anticancer moieties.

Ammonium glycyrrhizate skin delivery from ultradeformable liposomes: A novel use as an anti-inflammatory agent in topical drug delivery

Glycyrrhiza glabra L. is a native plant of Central and South-Western Asia that is also diffused in the Mediterranean area and contains several bioactive compounds such as: flavonoids, sterols, triterpene and saponins. Glycyrrhizin, containing glycyrrhizic and glycyrrhizinic acids has anti-inflammatory and antiallergic effects that are similar to corticosteroids. Ammonium glycyrrhizinate is a derivative salt of glycyrrhizic acid with similar anti-inflammatory activity that cannot pass through the skin due to its physicochemical properties and molecular weight. Although several nanoformulations, such as ethosomes, are designed to provide a systemic effect through a topical application, there are different limitations to the distribution inside the blood stream. For this reason, ultradeformable liposomes, or transfersomes, are selected to improve the topical delivery of drugs and allow the distribution of payloads in the blood stream because they pass intact through the stratum corneum epidermis barrier, due to the presence of sodium cholate, aqueous cutaneous gradient, and the rapid penetration of transfersomes by cutaneous tight junctions, thus allowing the systemic delivery of different therapeutic cargo in non-occlusive conditions. The aim of this work was the synthesis and physicochemical characterization of the ammonium glycyrrhizinate-loaded ultradeformable liposomes, the evaluation of drug release and permeation through stratum corneum and epidermis barrier. The in vivo anti-inflammatory effect of ammonium glycyrrhizinate-loaded ultradeformable liposomes was tested on human healthy volunteers. The results demonstrated that the ammonium glycyrrhizinate-loaded ultradeformable liposomes decreased the skin inflammation on the human volunteers and the resulting nanoformulations can be used as a potential topical drug delivery system for anti-inflammatory therapy. ^☆Parts of these results were presented as a poster communication at the Recent Developments in Pharmaceutical Analysis 2019 (RDPA 2019), Chieti, Italy.

Nanomedicine: A Promising Avenue for the Development of Effective Therapy for Breast Cancer

PURPOSE

Breast cancer is the most probable cancer among women. However, the available treatment is based on targeting different stages of breast cancer viz., radiation therapy, hormonal therapy, chemotherapy, and surgical interventions, which have some limitations. The available chemotherapeutics are associated with problems like low solubility, low permeability, high first-pass metabolism, and P-glycoprotein efflux. Hence, the aforementioned restrictions lead to ineffective treatment. Multiple chemotherapeutics can also cause resistance in tumors. So, the purpose is to develop an effective therapeutic regimen for the treatment of breast cancer by applying a nanomedicinal approach.

METHODS

This review has been conducted on a systematic search strategy, based on relevant literature available on Pub Med, MedlinePlus, Google Scholar, and Sciencedirect up to November 2019 using keywords present in abstract and title of the review. As per our inclusion and exclusion criteria, 226 articles were screened. Among 226, a total of 40 articles were selected for this review.

RESULTS

The significant findings with the currently available treatment is that the drug, besides its distribution to the target-specific site, also distributes to healthy cells, which results in severe side effects. Moreover, the drug is less bioavailable at the site of action; therefore, to overcome this, a high dose is required, which again causes side effects and lower the benefits. Nanomedicinal approaches give an alternative approach to avoid the associated problems of available chemotherapeutics treatment of breast cancer.

CONCLUSION

The nanomedicinal strategies are useful over the conventional treatment of breast cancer and deliver a target-specific drug-using different novel drug delivery approaches.

Novel Tamoxifen Nanoformulations for Improving Breast Cancer Treatment: Old Wine in New Bottles

Breast cancer (BC) is one of the leading causes of death from cancer in women; second only to lung cancer. Tamoxifen (TAM) is a hydrophobic anticancer agent and a selective estrogen modulator (SERM), approved by the FDA for hormone therapy of BC. Despite having striking efficacy in BC therapy, concerns regarding the dose-dependent carcinogenicity of TAM still persist, restricting its therapeutic applications. Nanotechnology has emerged as one of the most important strategies to solve the issue of TAM toxicity, owing to the ability of nano-enabled-formulations to deliver smaller concentrations of TAM to cancer cells, over a longer period of time. Various TAM-containing-nanosystems have been successfully fabricated to selectively deliver TAM to specific molecular targets found on tumour membranes, reducing unwanted toxic effects. This review begins with an outline of breast cancer, the current treatment options and a history of how TAM has been used as a combatant of BC. A detailed discussion of various nanoformulation strategies used to deliver lower doses of TAM selectively to breast tumours will then follow. Finally, a commentary on future perspectives of TAM being employed as a targeting vector, to guide the delivery of other therapeutic and diagnostic agents selectively to breast tumours will be presented.

Antitumor Features of Vegetal Protein-Based Nanotherapeutics

The introduction of nanotechnology into pharmaceutical application revolutionized the administration of antitumor drugs through the modulation of their accumulation in specific organs/body compartments, a decrease in their side-effects and their controlled release from innovative systems. The use of plant-derived proteins as innovative, safe and renewable raw materials to be used for the development of polymeric nanoparticles unlocked a new scenario in the drug delivery field. In particular, the reduced size of the colloidal systems combined with the peculiar properties of non-immunogenic polymers favored the characterization and evaluation of the pharmacological activity of the novel nanoformulations. The aim of this review is to describe the physico-chemical properties of nanoparticles composed of vegetal proteins used to retain and deliver anticancer drugs, together with the most important preparation methods and the pharmacological features of these potential nanomedicines.

Paclitaxel-loaded sodium deoxycholate-stabilized zein nanoparticles: characterization and in vitro cytotoxicity

Paclitaxel (PTX) is one of the most successful antineoplastic drugs and is widely used for the treatment of many forms of advanced and refractory cancer. Unfortunately, various drawbacks including non-selective cytotoxicity, poor water solubility and low bioavailability limit its clinical use. The aim of this study was to characterize a novel colloidal system made up of the natural protein zein, that would be able to efficiently retain the anticancer compound and increase its in vitro pharmacological effects. In fact, zein has promising characteristics that render it a potential material to be used in drug delivery application. The influences of temperature, pH and serum incubation on the stability of these particles, entrapment efficiency of PTX and in vitro toxicity on different cancer cell lines were evaluated. The nanosystems containing PTX demonstrated suitable storage stability, and were not destabilized by temperatures of up to 50 °C, pH alterations, the freeze-drying process or serum proteins. The encapsulation of PTX did not destabilize the structure of the zein nanoparticles and a suitable drug entrapment efficiency resulted. PTX-loaded zein nanoparticles showed an increased toxicity on different cancer cell lines with respect to the free drug, confirming its potential application in preclinical and clinical investigations.

Functionalized Large-Pore Mesoporous Silica Microparticles for Gefitinib and Doxorubicin Codelivery

Large-pore coralline mesoporous silica microparticles (CMS) were synthesized using the triblock polymer PEG-b-PEO-b-PEG and a hydrothermal method. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed the coralline morphology of the fabricated materials. The Brunauer⁻Emmett⁻Teller (BET) method and the Barrett⁻Joyner⁻Halenda (BJH) model confirmed the existence of large pores (20 nm) and of a tremendous specific surface area (663.865 m²·g-1) and pore volume (0.365 cm³·g-1). A novel pH-sensitive multiamine-chain carboxyl-functionalized coralline mesoporous silica material (CMS⁻(NH)₃⁻COOH) was obtained via a facile "grafting-to" approach. X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR) validated the effective interfacial functionalization of CMS with carboxyl and multiamine chains. The encapsulation and release behavior of the dual drug (gefitinib (GB) and doxorubicin (DOX)) was also investigated. It was found that CMS⁻(NH)₃⁻COOH allows rapid encapsulation with a high loading capacity of 47.36% for GB and 26.74% for DOX. Furthermore, the release profiles reveal that CMS⁻(NH)₃⁻COOH can preferably control the release of DOX and GB. The accumulative release rates of DOX and GB were 32.03% and 13.66%, respectively, at a low pH (pH 5.0), while they reduced to 8.45% and 4.83% at pH 7.4. Moreover, all of the modified silica nanoparticles exhibited a high biocompatibility with a low cytotoxicity. In particular, the cytotoxicity of both of these two drugs was remarkably reduced after being encapsulated. CMS⁻(NH)₃⁻COOH@GB@DOX showed tremendously synergistic effects of the dual drug in the antiproliferation and apoptosis of A549 human cancer cells in vitro.

A new therapeutic combination for osteosarcoma: Gemcitabine and Clofazimine co-loaded liposomal formulation

Osteosarcoma is the most common cancer in bone. Drug resistance is a challenge of current treatments that needs to be improved with novel treatment strategies. In this research, a new dual drug delivery system was developed with Gemcitabine (GEM) and Clofazimine (CLF) co-loaded liposome formulations. GEM is a well-known anticancer agent and CLF is a leprostatic and anti-inflammatory drug recently recognized as effective on cancer. GEM and CLF co-loaded liposomal formulation was achieved with compartmentalization as hydrophilic GEM being in core and lipophilic CLF sequestering in lipid-bilayer. Liposomes had high encapsulation efficiency (above 90%, GEM and above 80%, CLF). CLF release was enhanced while GEM release was slowed down in co-loaded liposomes compared to single cases. GEM/CLF co-loaded liposomes significantly enhanced cytotoxicity than GEM or CLF loaded liposomes on osteosarcoma cell line. CLF and GEM had synergistic effect (CI < 1). Results of flow cytometry showed higher apoptotic cell ratio, caspase-3 activity, mitochondrial membrane depolarized cells' ratio for GEM/CLF co-loaded liposome treatments than other liposomes. Cytotoxicity of CLF on bone cancer cells and also its synergistic effect with GEM on osteosarcoma is reported for the first time with this study. CLF's loading with GEM into liposome was also a new approach for enhancement of anticancer effect on Saos-2 cells. Therefore, GEM/CLF co-loaded liposomal delivery system is proposed as a novel approach for treatment of osteosarcoma.

Development and characterization of gemcitabine hydrochloride loaded lipid polymer hybrid nanoparticles (LPHNs) using central composite design

Lipid polymer hybrid nanoparticles (LPHNs) combine the characteristics and beneficial properties of both polymeric nanoparticles and liposomes. The objective of this study was to design and optimize gemcitabine hydrochloride loaded LPHNs based on the central composite design approach. PLGA 50:50/PLGA 65:35 mass ratio (w/w), soya phosphatidylcholine (SPC)/polymer mass ratio (%, w/w) and amount of DSPE-PEG were chosen as the investigated independent variables. The LPHNs were prepared with modified double emulsion solvent evaporation method and characterized by testing their particle size, encapsulation efficiency, and cumulative release. The composition of optimal formulation was determined as 1,5 (w/w) PLGA 50:50/PLGA 65:35 mass ratio, 30% (w/w) SPC/polymer mass ratio and 15 mg DSPE-PEG. The results showed that the optimal formulation gemcitabine hydrochloride loaded LPHNs had encapsulation efficiency of 45,2%, particle size of 237 nm and cumulative release of 62,3% at the end of 24 h. The morphology of LPHNs was found to be spherical by transmission electron microscopy (TEM) observation. Stability studies showed that LPHNs were physically stable until 12 months at 4 °C and 9 months at 25 °C/60% RH. The results suggest that the LPHNs can be an effective drug delivery system for hydrophilic active pharmaceutical ingredient.

Seek and destroy: improving PK/PD profiles of anticancer agents with nanoparticles

INTRODUCTION

The Pharmacokinetics/pharmacodynamics (PK/PD) relationships with cytotoxics are usually based on a steepening concentration-effect relationship; the greater the drug amount, the greater the effect. The Maximum Tolerated Dose paradigm, finding the balance between efficacy, while keeping toxicities at their manageable level, has been the rule of thumb for the last 50-years. Developing nanodrugs is an appealing strategy to help broaden this therapeutic window. The fact that efficacy and toxicity with cytotoxics are intricately linked is primarily due to the complete lack of specificity toward the tumor tissue during their distribution phase. Because nanoparticles are expected to better target tumor tissue while sparing healthy cells, accumulating large amounts of cytotoxics in tumors could be achieved in a safer way. Areas covered: This review aims at presenting how nanodrugs present unique features leading to reconsidering PK/PD relationships of anticancer agents. Expert commentary: The constant interplay between carrier PK, interactions with cancer cells, payload release, payload PK, target expression and target engagement, makes picturing the exact PK/PD relationships of nanodrugs particularly challenging. However, those improved PK/PD relationships now make the once contradictory higher efficacy and lower toxicities requirement an achievable goal in cancer patients.

Anti-hTERT siRNA-Loaded Nanoparticles Block the Growth of Anaplastic Thyroid Cancer Xenograft

The high frequency of hTERT-promoting mutations and the increased expression of hTERT mRNA in anaplastic thyroid cancer (ATC) make TERT a suitable molecular target for the treatment of this lethal neoplasm. In this study, we encapsulated an anti-hTERT oligonucleotide in biocompatible nanoparticles and analyzed the effects of this novel pharmaceutical preparation in preclinical models of ATC. Biocompatible nanoparticles were obtained in an acidified aqueous solution containing chitosan, anti-hTERT oligoRNAs, and poloxamer 188 as a stabilizer. The effects of these anti-hTERT nanoparticles (Na-siTERT) were tested in vitro on ATC cell lines (CAL-62 and 8505C) and in vivo on xenograft tumors obtained by flank injection of CAL-62 cells into SCID mice. The Na-siTERT reduced the viability and migration of CAL-62 and 8505C cells after 48-hour incubation. Intravenous administration (every 48 hours for 13 days) of this encapsulated drug in mice hosting a xenograft thyroid cancer determined a great reduction in the growth of the neoplasm (about 50% vs. untreated animals or mice receiving empty nanoparticles), and decreased levels of Ki67 associated with lower hTERT expression. Moreover, the treatment resulted in minimal invasion of nearby tissues and reduced the vascularity of the xenograft tumor. No signs of toxicity appeared following this treatment. Telomere length was not modified by the Na-siTERT, indicating that the inhibitory effects of neoplasm growth were independent from the enzymatic telomerase function. These findings demonstrate the potential suitability of this anti-TERT nanoparticle formulation as a novel tool for ATC treatment. Mol Cancer Ther; 17(6); 1187-95. ©2018 AACR.

Combination of using prodrug-modified cationic liposome nanocomplexes and a potentiating strategy via targeted co-delivery of gemcitabine and docetaxel for CD44-overexpressed triple negative breast cancer therapy

In this study, novel prodrug-modified cationic liposome nanocomplexes (Combo NCs) were reported for gemcitabine (GEM) and docetaxel (DTX) co-delivery. This nanoplatform exhibited multiple favorable characteristics, such as a 'green' fabrication with a one-step chemical reaction, appropriate size (∼200nm) and distribution (PDI<0.2), low zeta potential (-31.1mv), high drug-loading efficiency (9.3% GEM plus 3.1% DTX, wt%) and pH and enzymatic dual-stimulus-responsive release properties. Immunofluorescence and cellular uptake studies showed that Combo NCs efficiently targeted overexpressed CD44 in MDA-MB-231 carcinoma. In vitro studies revealed that Combo NCs played a critical role in the synergistic induction of cytotoxicity, apoptosis and inhibition of wound healing. Combo NCs were confirmed to exhibit great potency for increasing S phase arrest and remodeling the CDA and dCK balance by decreasing the mRNA expression of CDA down to 0.09-fold and increasing the mRNA expression of dCK by 1.36-fold, remarkably increasing the dCK/CDA ratio to 15.3-fold compared with the blank control. The biodistribution results obtained in vivo revealed an effective accumulation in tumor foci. All of these advantages of Combo NCs contributed to their remarkable anti-tumor efficacy without systemic toxicity as well as their apoptosis-enhancing and anti-proliferative capacities, as determined by TUNEL and Ki67 immunohistochemistry in vivo. Consequently, such a rationally contemplated co-delivery system demonstrated the promising potential of clinical applications for triple-negative breast cancer therapy.

STATE OF SIGNIFICANCE

The Combo NCs were innovatively applied for co-delivery of hydrophilic GEM and hydrophobic DTX. The ester bond linking and shielding effect of HA-GEM made the carriers achieve synchronous release properties, which was determined in in vitro release study. Due to the HA modification, the vectors own great potency for positive targeting to CD44 overexpressed triple-negative breast cancer cells MDA-MB-231. Cytotoxicity and apoptosis studies confirmed the targeting effect and synergism between two drugs. Interestingly, we found in cell cycle study, drug combinations (free combination or Combo NCs) didn't show a rise in G2M phase, which was significantly higher when treated DTX alone. We further discovered the role of DTX in combinations may involve in modulating GEM associated enzymes thus enhancing the efficacy of GEM. Consequently, this nanoplatform provided a novel solution for achieving targeted co-delivery and potentiating effect in cancer therapy.

Preparation and Evaluation of 177Lu-Labeled Gemcitabine: An Effort Toward Developing Radiolabeled Chemotherapeutics for Targeted Therapy Applications

OBJECTIVE

Gemcitabine, a nucleoside analogue, is used as a chemotherapeutic drug for the treatment of a wide variety of cancers. Therefore, radiolabeled gemcitabine may have potential as a radiotherapeutic agent for the treatment of various types of cancers. In the present work, an attempt has been made to radiolabel gemcitabine with ¹⁷⁷Lu and study the preliminary biological behavior of ¹⁷⁷Lu-labeled gemcitabine in tumor-bearing animal model.

EXPERIMENTAL

Gemcitabine was coupled with p-NCS-benzyl-DOTA, a bifunctional chelating agent, to facilitate radiolabeling with ¹⁷⁷Lu. The p-NCS-benzyl-DOTA-gemcitabine conjugate was radiolabeled with ¹⁷⁷Lu, produced in-house and characterized by high-performance liquid chromatography. Tumor targeting potential of the radiolabeled agent was determined by biodistribution studies in Swiss mice bearing fibrosarcoma tumors.

RESULTS

¹⁷⁷Lu-gemcitabine was prepared with a radiochemical purity of 95.7% ± 0.3% under the optimized reaction conditions. The radiolabeled agent showed adequate in vitro stability in normal saline as well as in human blood serum. Preliminary biological studies revealed rapid and significant accumulation of the radiotracer in the tumorous lesions along with fast clearance of activity from blood and other vital organs/tissue. Although tumor uptake gradually reduced with time, tumor to blood and tumor to muscle ratios were improved due to the comparatively faster clearance of activity from the nontarget organs/tissue.

CONCLUSION

The present study demonstrates the preliminary potential of ¹⁷⁷Lu-gemcitabine for targeted radiotherapy. However, further studies are warranted to assess its potential for radiotherapeutic applications.

Detection and Physicochemical Characterization of Membrane Vesicles (MVs) of Lactobacillus reuteri DSM 17938

Membrane vesicles (MVs) are bilayer structures which bleb from bacteria, and are important in trafficking biomolecules to other bacteria or host cells. There are few data about MVs produced by the Gram-positive commensal-derived probiotic Lactobacillus reuteri; however, MVs from this species may have potential therapeutic benefit. The aim of this study was to detect and characterize MVs produced from biofilm (bMVs), and planktonic (pMVs) phenotypes of L. reuteri DSM 17938. MVs were analyzed for structure and physicochemical characterization by Scanning Electron Microscope (SEM) and Dynamic Light Scattering (DLS). Their composition was interrogated using various digestive enzyme treatments and subsequent Transmission Electron Microscopy (TEM) analysis. eDNA (extracellular DNA) was detected and quantified using PicoGreen. We found that planktonic and biofilm of L. reuteri cultures generated MVs with a broad size distribution. Our data also showed that eDNA was associated with pMVs and bMVs (e_MVsDNA). DNase I treatment demonstrated no modifications of MVs, suggesting that an eDNA-MVs complex protected the e_MVsDNA. Proteinase K and Phospholipase C treatments modified the structure of MVs, showing that lipids and proteins are important structural components of L. reuteri MVs. The biological composition and the physicochemical characterization of MVs generated by the probiotic L. reuteri may represent a starting point for future applications in the development of vesicles-based therapeutic systems.

Hesperetin Liposomes for Cancer Therapy

Hesperetin is a compound from citrus fruit that has previously been found to exert anticancer activity through a variety of mechanisms. However, the application of hesperetin to cancer therapy has been hampered by its hydrophobicity, necessitating the use of toxic solubilizing agents. Here, we have developed the first liposome-based delivery system for hesperetin. Liposomes were fabricated using the thin-layer evaporation technique and physical and pharmacological parameters were measured. The liposomes remained stable for prolonged periods of time in serum and under storage conditions, and displayed anticancer efficacy in both H441 lung cancer cells and MDA-MB-231 breast cancer cells. Furthermore, the anticancer activity was not impaired in cells expressing the multidrug resistance protein 1 (MDR-1). In conclusion, the encapsulation of hesperetin in liposomes does not interfere with therapeutic efficacy and provides a biocompatible alternative to toxic solubilizing agents, thereby enabling future clinical use of this compound for cancer therapy.

Anticancer activity of all-trans retinoic acid-loaded liposomes on human thyroid carcinoma cells

All-trans retinoic acid (ATRA) is an anti-tumor compound, exerting different anti-cancer effects on different types of cancer cells. Unfortunately, retinoids are also characterized by certain side effects following systemic administration, such as the burning of skin and general malaise. The highly variable degree of bioavailability of ATRA plus its tendency to induce its own destruction through metabolic degradation following oral treatment necessitate the development of alternative formulations. The aim of this work is to evaluate the physico-chemical properties of unilamellar, ATRA-containing liposomes and to investigate the cytotoxic activity of this potential nanomedicine on human thyroid carcinoma cells. Liposomes made up of DPPC/Chol/DSPE-mPEG2000 (6:3:1 molar ratio), characterized by a mean diameter of ∼200nm, a polydispersity index of 0.1 and a negative surface charge, were used as ATRA-carriers and their antiproliferative efficacy was investigated in comparison with the free drug on three different human thyroid carcinoma cell lines (PTC-1, B-CPAP, and FRO) through MTT-testing. The liposomes protected the ATRA against photodegradation and increased its antiproliferative properties due to the improvement of its cellular uptake. ATRA-loaded liposomes could be a novel formulation useful for the treatment of anaplastic thyroid carcinoma.

Trends on polymer- and lipid-based nanostructures for parenteral drug delivery to tumors

PURPOSE

The dawn of the state-of-the-art methods of cancer treatments, nano-based delivery systems, has dispensed with the mainstream chemotherapy for being inadequate in yielding productive results and the numerous reported side effects. The popularity of this complementary approach in the course of the last two decades has been primarily attributed to its capacity to elevate the therapeutic index of anticancer drugs as well as removing the impassable delivery barriers in solid tumors with the minimal damage to the normal tissues.

METHODS

The PubMed database was consulted to compile this review.

RESULTS

A wide range of minuscule organic and inorganic nanomaterials, with dimensions not exceeding hundred nanometers, has led to hope for cancer therapy to flare-up once again due to possessing a number of exclusive traits for passive and active tumor targeting, some of which are EPR effect, high interstitial pressure of tumor, overexpressed receptors and angiogenesis. Although a limited number of liposomal and polymer-based therapeutic nanoparticles have gained applicability, a vast number of nanoparticles are still being trailed in order to be fully developed.

CONCLUSIONS

This study provides an overview of the advantages/disadvantages of nanocarriers for cancer drug delivery.

Biomimetic proteolipid vesicles for targeting inflamed tissues

A multitude of micro- and nanoparticles have been developed to improve the delivery of systemically administered pharmaceuticals, which are subject to a number of biological barriers that limit their optimal biodistribution. Bioinspired drug-delivery carriers formulated by bottom-up or top-down strategies have emerged as an alternative approach to evade the mononuclear phagocytic system and facilitate transport across the endothelial vessel wall. Here, we describe a method that leverages the advantages of bottom-up and top-down strategies to incorporate proteins derived from the leukocyte plasma membrane into lipid nanoparticles. The resulting proteolipid vesicles-which we refer to as leukosomes-retained the versatility and physicochemical properties typical of liposomal formulations, preferentially targeted inflamed vasculature, enabled the selective and effective delivery of dexamethasone to inflamed tissues, and reduced phlogosis in a localized model of inflammation.

Recent advances in drug delivery strategies for improved therapeutic efficacy of gemcitabine

Gemcitabine (2',2'-difluoro-2'-deoxycytidine; dFdC) is an efficacious anticancer agent acting against a wide range of solid tumors, including pancreatic, non-small cell lung, bladder, breast, ovarian, thyroid and multiple myelomas. However, short plasma half-life due to metabolism by cytidine deaminase necessitates administration of high dose, which limits its medical applicability. Further, due to its hydrophilic nature, it cannot traverse cell membranes by passive diffusion and, therefore, enters via nucleoside transporters that may lead to drug resistance. To circumvent these limitations, macromolecular prodrugs and nanocarrier-based formulations of Gemcitabine are gaining wide recognition. The nanoformulations based approaches by virtue of their controlled release and targeted delivery have proved to improve bioavailability, increase therapeutic efficacy and reduce adverse effects of the drug. Furthermore, the combination of Gemcitabine with other anticancer agents as well as siRNAs using nanocarriers has also been investigated in order to enhance its therapeutic potential. This review deals with challenges and recent advances in the delivery of Gemcitabine with particular emphasis on macromolecular prodrugs and nanomedicines.

PDE5 Inhibitors-Loaded Nanovesicles: Physico-Chemical Properties and In Vitro Antiproliferative Activity

Novel therapeutic approaches are required for the less differentiated thyroid cancers which are non-responsive to the current treatment. In this study we tested an innovative formulation of nanoliposomes containing sildenafil citrate or tadalafil, phosphodiesterase-5 inhibitors, on two human thyroid cancer cell lines (TPC-1 and BCPAP). Nanoliposomes were prepared by the thin layer evaporation and extrusion methods, solubilizing the hydrophilic compound sildenafil citrate in the aqueous phase during the hydration step and dissolving the lipophilic tadalafil in the organic phase. Nanoliposomes, made up of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylcholine monohydrate (DPPC), cholesterol, and N-(carbonyl-methoxypolyethylene glycol-2000)-1,2-distearoyl-sn-glycero-3-phosphoethanolamine (DSPE-mPEG2000) (6:3:1 molar ratio), were characterized by a mean diameter of ~100 nm, a very low polydispersity index (~0.1) and a negative surface charge. The drugs did not influence the physico-chemical properties of the systems and were efficiently retained in the colloidal structure. By using cell count and MTT assay, we found a significant reduction of the viability in both cell lines following 24 h treatment with both nanoliposomal-encapsulated drugs, notably greater than the effect of the free drugs. Our findings demonstrate that nanoliposomes increase the antiproliferative activity of phosphodiesterase-5 inhibitors, providing a useful novel formulation for the treatment of thyroid carcinoma.

Cationic Supramolecular Vesicular Aggregates for Pulmonary Tissue Selective Delivery in Anticancer Therapy

The biopharmaceutical properties of supramolecular vesicular aggregates (SVAs) were characterized with regard to their physicochemical features and compared with cationic liposomes (CLs). Neutral and cationic SVAs were synthesized using two different copolymers of poly(aspartyl hydrazide) by thin-layer evaporation and extrusion techniques. Both copolymers were self-assembled in pre-formulated liposomes and formed neutral and cationic SVAs. Gemcitabine hydrochloride (GEM) was used as an anticancer drug and loaded by a pH gradient remote loading procedure, which significantly increased drug loading inside the SVAs. The resulting average size of the SVAs was 100 nm. The anticancer activity of GEM-loaded neutral and cationic SVAs was tested in human alveolar basal epithelial (A549) and colorectal cancer (CaCo-2) cells. GEM-loaded cationic SVAs increased the anticancer activity in A549 and CaCo-2 cells relative to free drug, neutral SVAs, and CLs. In vivo biodistribution in Wistar rats showed that cationic SVAs accumulate at higher concentrations in lung tissue than neutral SVAs and CLs. Cationic SVAs may therefore serve as an innovative future therapy for pulmonary carcinoma.

Engineered Nanoparticles Against MDR in Cancer: The State of the Art and its Prospective

Cancer is a highly heterogeneous disease at intra/inter patient levels and known as the leading cause of death worldwide. A variety of mono and combinational therapies including chemotherapy have been evolved over the years for its effective treatment. However, advent of chemotherapeutic resistance or multidrug resistance (MDR) in cancer is a major challenge researchers are facing in cancer chemotherapy. MDR is a complex process having multifaceted non-cellular or cellular-based mechanisms. Research in the area of cancer nanotechnology over the past two decade has now proven that the smartly designed nanoparticles help in successful chemotherapy by overcoming the MDR and preferentially accumulate in the tumor region by means of active and passive targeting therefore reducing the offtarget accumulation of payload. Many of such nanoparticles are in different stages of clinical trials as nanomedicines showing promising result in cancer therapy including the resistant cases. Nanoparticles as chemotherapeutics carriers offer the opportunity to have multiple payload of drug and or imaging agents for combinational and theranostics therapy. Moreover, nanotechnology further bring in notice the new treatment strategies such as combining the NIR, MRI and HIFU in cancer chemotherapy and imaging. Here, we discussed the cellular/non-cellular factors constituting the MDR in cancer and the role of nanomedicines in effective chemotherapy of MDR cases of cancers. Moreover, recent advancements like combinational payload delivery and combined physical approach with nanotechnology in cancer therapy have also been discussed.

Synergistic effect of PEGylated resveratrol on delivery of anticancer drugs

Resveratrol (RES) is a natural polyphenol which can be considered as a nutraceutical because of its benefits such as anticancer and antioxidant activity. In this paper, we designed polymer-RES conjugates as anticancer drug carrier for synergistic therapeutic effect in cancer treatment. Bicalutamide (BIC) was used as a model drug to investigate the drug release behaviors and in vitro anticancer performance. PEG-RES and PEG-Glycine-RES nanoparticles were prepared and characterized. The size of the prepared particles was around 50 nm with RES content of 17.2 and 16.3 wt% for PEG-RES and PEG-Glycine-RES, respectively, and BIC loading efficiency were of 81.6% and 84.5%, separately. Release rate of RES from conjugates depended on the stability of ester group against hydrolysis. BIC release was much faster than RES release. The anticancer activity of BIC loaded PEGylated RES nanoparticles was much better than that of free BIC, indicating the conjugates provided a synergetic cytotoxicity to cancer cells. Confocal laser scanning microscopy observation and flow cytometry analyses indicated that PEGylated RES conjugates were more efficiently internalized into cells, released drug into cytoplasm. These results suggest that PEGylated RES conjugates show great potential for cancer therapy.

Pleiotropic Role of Dietary Phytochemicals in Cancer: Emerging Perspectives for Combinational Therapy

Cancer is considered a complicated health issue worldwide. The mean cancer survival through standard therapeutic strategies has not been significantly improved over the past few decades. Hence, alternate remedies are needed to treat or prevent this dreadful disease being explored. Currently, it has been recognized that repeated treatment with chemotherapeutic agents has been largely ineffective due to multidrug resistance and further conventional treatment possesses limited drug accessibility to cancerous tissues, which in turn necessitates a higher dose resulting in increased cytotoxicity. Drug combinations have been practiced to address the problems associated with conventional single drug treatment. Recently, natural dietary agents have attracted much attention in cancer therapy because of their synergistic effects with anticancer drugs against different types of cancer. Natural phytochemicals may execute their anticancer activity through targeting diverse cancer cell signaling pathways, promoting cell cycle arrest and apoptosis, regulating antioxidant status and detoxification. This review focuses mainly on the anticancer efficacy of dietary phytochemicals in combination with standard therapeutic drugs reported from various in vitro and in vivo experimental studies apart from clinical trials. This review adds knowledge to the field of intervention studies using combinational modalities that opens a new window for cancer treatment/chemoprevention.

Sequential gemcitabine and tamoxifen treatment enhances apoptosis and blocks transformation in bladder cancer cells

Bladder cancer is a common malignancy for which regional or metastatic disease is identified at diagnosis. The aim of this study was to determine whether tamoxifen (Tam), an estrogen receptor (ER) antagonist, can sensitize bladder cancer cell lines to gemcitabine (Gem) chemotherapy. ERα and ERβ protein levels were determined in each cell line using western blot analysis. The TCC-Sup, 5637, and RT4 bladder cancer cells were exposed to various concentrations and regimens of Tam or Gem alone or in combination. Cell viability and apoptosis were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and propidium iodide followed by flow cytometry. Apoptosis was then evaluated by western blot analysis. Treated TCC-Sup cells were subjected to soft agar colony formation assay to determine the cellular transformation. Western blot analysis results revealed ER expression in the three cell lines. TCC-Sup and 5637 cells treated with a combination of Tam and Gem had lower cell viabilities than those treated with Tam or Gem alone for 72 h in TCC-Sup and 5637. Compared with the other treatments, sequential Gem followed by Tam (Gem→Tam) treatment caused the largest increase in DNA fragmentation at 72 h in TCC-Sup cells. Western blot analysis results revealed that this sequential Gem→Tam treatment increased poly(ADP-ribose) polymerase cleavage in TCC-Sup cells. Sequential Gem→Tam inhibited the cell transformation in TCC-Sup cells. In conclusion, sequential Gem→Tam enhanced the cytotoxicity of Gem in vitro. This regimen be useful to enhance the efficacy of Gem in bladder cancer. However, future in vivo studies are required to verify the results.

Preparation and Characterization of Naringenin-Loaded Elastic Liposomes for Topical Application

Excessive production of radical oxygen species in skin is a contributor to a variety of skin pathologies. Naringenin is a potent antioxidant. The purpose of the present study was to develop elastic liposomes for naringenin topical application. Naringenin-loaded elastic liposomes containing different amounts of Tween 80 and cholesterol were prepared. The physicochemical properties including vesicle size, surface charge, encapsulation efficiency, and permeability capacity were determined to evaluate the effect of components. The stability of formulation and skin irritation caused by drug-loaded elastic liposomes were also evaluated for assessment of the clinical utility of elastic liposomes. Saturated aqueous solution of naringenin and naringenin dissolved in 10% Tween 80 solution (5 mg/mL) were used as the control group. The result showed that in using elastic liposomes as carrier, the deposition amounts in the skin of naringenin were significantly increased about 7.3~11.8-fold and 1.2~1.9-fold respectively, when compared with the saturated aqueous solution and Tween 80 solution-treated groups. The level of drug was more than 98.89±3.90% after 3 months of storage at 4℃. In a skin irritation test, the result showed experimental formulation exhibit considerably less irritating than the positive control (paraformaldehyde-treated) group, suggesting its potential therapeutic application.

Targeting cancer cells in the tumor microenvironment: opportunities and challenges in combinatorial nanomedicine

Cancer therapies of the future will rely on synergy between drugs delivered in combination to achieve both maximum efficacy and decreased toxicity. Nanoscale drug delivery vehicles composed of highly tunable nanomaterials ('nanocarriers') represent the most promising approach to achieve simultaneous, cell-selective delivery of synergistic ratios of combinations of drugs within solid tumors. Nanocarriers are currently being used to co-encapsulate and deliver synergistic ratios of multiple anticancer drugs to target cells within solid tumors. Investigators exploit the unique environment associated with solid tumors, termed the tumor microenvironment (TME), to make 'smart' nanocarriers. These sophisticated nanocarriers exploit the pathological conditions in the TME, thereby creating highly targeted nanocarriers that release their drug payload in a spatially and temporally controlled manner. The translational and commercial potential of nanocarrier-based combinatorial nanomedicines in cancer therapy is now a reality as several companies have initiated human clinical trials.

Nonspecifically enhanced therapeutic effects of vincristine on multidrug-resistant cancers when coencapsulated with quinine in liposomes

The use of vincristine (VCR) to treat cancer has been limited by its dose-dependent toxicity and development of drug resistance after repeated administrations. In this study, we investigated the mechanism by which quinine hydrochloride (QN) acts as a sensitizer for VCR. Our experiments used three kinds of multidrug-resistant cancer cells and demonstrated that QN worked by inducing intracellular depletion of adenosine triphosphate, increasing adenosine triphosphatase activity, and decreasing P-glycoprotein expression. Based on these results, we designed and prepared a VCR and QN codelivery liposome (VQL) and investigated the effect of coencapsulated QN on the in vitro cytotoxicity of VCR in cells and three-dimensional multicellular tumor spheroids. The antitumor effects of the formulation were also evaluated in multidrug-resistant tumor-bearing mice. The results of this in vivo study indicated that VQL could reverse VCR resistance. In addition, it reduced tumor volume 5.4-fold when compared with other test groups. The data suggest that VQL could be a promising nanoscaled therapeutic agent to overcome multidrug resistance, and may have important clinical implications for the treatment of cancer.

Polyaspartamide-doxorubicin conjugate as potential prodrug for anticancer therapy

PURPOSE

To synthesize a new polymeric prodrug based on α,β-poly(N-2-hydroxyethyl)(2-aminoethylcarbamate)-d,l-aspartamide copolymer bearing amine groups in the side chain (PHEA-EDA), covalently linked to the anticancer drug doxorubicin and to test its potential application in anticancer therapy.

METHODS

The drug was previously derivatized with a biocompatible and hydrophilic linker, leading to a doxorubicin derivative highly reactive with amino groups of PHEA-EDA. The PHEA-EDA-DOXO prodrug was characterized in terms of chemical stability. The pharmacokinetics, biodistribution and cytotoxicity of the product was investigated in vitro and in vivo on human breast cancer MCF-7 and T47D cell lines and NOD-SCID mice bearing a MCF-7 human breast carcinoma xenograft. Data collected were compared to those obtained using free doxorubicin.

RESULTS

The final polymeric product is water soluble and easily hydrolysable in vivo, due to the presence of ester and amide bonds along the spacer between the drug and the polymeric backbone. In vitro tests showed a retarded cytotoxic effect on tumor cells, whereas a significant improvement of the in vivo antitumor activity of PHEA-EDA-DOXO and a survival advantage of the treated NOD-SCID mice was evidenced, compared to that of free doxorubicin.

CONCLUSIONS

The features of the PHEA-EDA-DOXO provide a potential protection of the drug from the plasmatic enzymatic degradation and clearance, an improvement of the blood pharmacokinetic parameters and a suitable body biodistribution. The data collected support the promising rationale of the proposed macromolecular prodrug PHEA-EDA-DOXO for further potential development and application in the treatment of solid cancer diseases.