Drug delivery design for intravenous route with integrated physicochemistry, pharmacokinetics and pharmacodynamics: illustration with the case of taxane therapeutics

Cabazitaxel-Loaded Thermosensitive Hydrogel System for Suppressed Orthotopic Colorectal Cancer and Liver Metastasis

The treatment of colorectal cancer is always a major challenge in the field of cancer research. The number of estimated new cases of colorectal cancer worldwide in 2020 is 1 148 515, and the estimated number of deaths is 576 858, revealing that mortality accounted for approximately half of the disease incidence. The development of new drugs and strategies for colorectal cancer treatment is urgently needed. Thermosensitive injectable hydrogel PDLLA-PEG-PDLLA (PLEL) loaded with cabazitaxel (CTX) is used to explore its anti-tumor effect on mice with orthotopic colorectal cancer. CTX/PLEL is characterized by a solution state at room temperature and a hydrogel state at physiologic temperature. The excipients MPEG-PCL and PDLLA-PEG-PDLLA have good biocompatibility and biodegradability. The simple material synthesis and preparation process renders this system cost-effective and more conducive to clinical transformation. An orthotopic colorectal cancer model is established by transplantation subcutaneous tumors onto the cecum of mice. According to the results of experiments in vivo, CTX/PLEL significantly inhibits orthotopic colorectal cancer and liver metastasis in mice. The results indicate that CTX/PLEL nanoparticle preparations have high security and excellent anti-tumor effects, and have great application potential in colorectal cancer therapy.

Hypersensitivity Reactions to Taxanes: A Multicenter Study for Outcomes and Safety of Rapid Drug Desensitization

PURPOSE

Taxanes can cause hypersensitivity reactions (HSRs), which pose a significant challenge in the treatment of malignancies. Patients who are eligible for rapid drug desensitization (RDD) can continue treatment; however, some patients experience breakthrough reactions (BTRs). Data about risk factors for BTRs during RDDs in patients with HSRs to taxanes are limited.

METHODS

This was a multicenter, retrospective study of patients with immediate-HSRs to taxanes. Initial HSRs were classified as grade 1, 2, or 3 based on severity. Prick/intradermal skin tests were performed with implicated taxanes. A 12-step protocol was used during RDD.

RESULTS

The study comprised 75 patients (F/M: 63/12, mean age 49.92 ± 11.72 years, 43 HSRs to paclitaxel, 32 HSRs to docetaxel). The majority of reactions (86.7%) occurred during the first or second exposure. The prevalence of drug allergy history was higher in patients with paclitaxel HSR than in those with docetaxel HSR, although it was not statistically significant (23.3% vs. 6.3%). The initial HSRs were mostly grade 2 (n = 50, 66.7%) or grade 3 (n = 22, 29.3%). Skin tests with implicated taxanes were done on 48 patients, and the rate of positive response in patients with grade 1, 2, and 3 initial HSRs were 50%, 17.6%, and 16.7%, respectively. . A total of 255 RDDs were completely performed, although BTRs occurred in 27 (grade 1, 55.6%; grade 2, 40.7%; grade 3, 3.7%). There were no statistically significant correlations between the risk of BTR and age, drug cycle, gender, positivity of skin test or atopy. The step reduction was successfully done on 9 eligible patients with mild or moderate HSRs during the 12-step RDDs.

CONCLUSIONS

Our experience demonstrates a 100% success rate in completing the 255 RDDs for taxanes, affirming the safety and efficacy of the RDD within the study population.

Cabazitaxel prodrug nanoassemblies with branched chain modifications: Narrowing the gap between efficacy and safety

The clinical application of cabazitaxel (CTX) is restricted by severe dose-related toxicity, failing to considering therapeutic efficacy and safety together. Self-assembled prodrugs promote new drug delivery paradigms as they can self-deliver and self-formulate. However, the current studies mainly focused on the use of straight chains to construct self-assembled prodrugs, and the role of branched chains in prodrug nanoassemblies remains to be clarified. In this study, we systematically explored the structure-function relationship of prodrug nanoassemblies using four CTX prodrugs that contained branched chain aliphatic alcohols (BAs) with different alkyl lengths. Overall, CTX-SS-BA20 NPs with the proper alkyl length exhibited significant improvements in both antitumor efficacy and biosafety. Furthermore, compared with straight chain (SC) modified prodrug nanoassemblies (CTX-SS-SC20 NPs), CTX-SS-BA20 NPs still hold great therapeutic promise due to its good biosafety. These findings illustrated the significance of BAs as modified chains in designing prodrug nanoassemblies for narrowing the efficacy-to-safety gap of cancer therapy.

Triple Negative Breast Cancer Treatment Options and Limitations: Future Outlook

Triple negative breast cancer (TNBC) has a negative expression of estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptors (HER2). The survival rate for TNBC is generally worse than other breast cancer subtypes. TNBC treatment has made significant advances, but certain limitations remain. Treatment for TNBC can be challenging since the disease has various molecular subtypes. A variety of treatment options are available, such as chemotherapy, immunotherapy, radiotherapy, and surgery. Chemotherapy is the most common of these options. TNBC is generally treated with systemic chemotherapy using drugs such as anthracyclines and taxanes in neoadjuvant or adjuvant settings. Developing resistance to anticancer drugs and off-target toxicity are the primary hindrances to chemotherapeutic solutions for cancer. It is imperative that researchers, clinicians, and pharmaceutical companies work together to develop effective treatment options for TNBC. Several studies have suggested nanotechnology as a potential solution to the problem of suboptimal TNBC treatment. In this review, we summarized possible treatment options for TNBC, including chemotherapy, immunotherapy, targeted therapy, combination therapy, and nanoparticle-based therapy, and some solutions for the treatment of TNBC in the future. Moreover, we gave general information about TNBC in terms of its characteristics and aggressiveness.

A novel micellar carrier to reverse multidrug resistance of tumours: TPGS derivatives with end-grafted cholesterol

D-α-tocopherol polyethylene glycol succinate (TPGS) has good biocompatibility, low immunogenicity, prolonged circulation time, and it can reverse multidrug resistance of tumours. However, the micelle concentration (CMC) of TPGS is too high (0.2 mg/mL) to develop the formulation of the micelle. In this study, TPGS was modified with cholesterol to obtain a new carrier material, TPGS-CHMC. The CMC of TPGS-CHMC was 2 μg/mL, which was extremely lower than that of TPGS. Docetaxel (DTX)-loaded TPGS-CHMC micelles (TPGS-CHMC/DTX) exhibited an average size of approximately 13 nm, a zeta potential of approximately -4.66 mV, and high encapsulation efficiency (99.2 ± 0.6%). TPGS-CHMC reduced mitochondrial membrane potential and cell membrane fluidity in paclitaxel-resistant ovarian cancer cells (A2780/T). In vivo, DiR-loaded TPGS-CHMC micelles were selectively distributed in A2780/T tumour-bearing nude mice. In A2780/T tumour-bearing nude mice, TPGS-CHMC/DTX micelles displayed significantly higher anti-tumour activity and less toxicity than the free DTX solution. In summary, TPGS-CHMC has various advantages, and provides a new option for developing functional polymeric micelles.

Dual degradation mechanism of GPX4 degrader in induction of ferroptosis exerting anti-resistant tumor effect

Targeting Glutathione peroxidase 4 (GPX4) has become a promising strategy for drug-resistant cancer therapy via ferroptosis induction. It was found that the GPX4 inhibitors such as RSL3 have GPX4 degradation ability via not only autophagy-lysosome pathway but also ubiquitin-proteasome system (UPS). Proteolysis targeting chimeras (PROTACs) using small molecule with both inhibition and degradation ability as the ligand of protein of interest (POI) have not been reported. To obtain better compounds with effective disturbance of GPX4 activity, and compare the difference between GPX4 inhibitors with degradation ability and their related PROTACs, we designed and synthesized a series of GPX4 degraders using PROTAC technology in terms of its excellent characteristics such as high efficiency and selectivity and the capacity of overcoming resistance. Hence, 8e was discovered as a potent and highly efficacious GPX4 degrader based upon the inhibitor RSL3. It was 2-3 times more potent than RSL3 in all the in vitro anti-tumor assays, indicating the importance of the PROTAC ternary complex of GPX4, 8e and E3 ligase ligand. 8e revealed better potency in resistant tumor cells than in wide type cells. Furthermore, we discovered for the first time that degrader 8e exhibit GPX4 degradation activity via ubiquitin-proteasome system (UPS) and autophagy-lysosome pathway with UPS plays the major role in the process. Our data also suggested that 8e and RSL3 could potently induce ferroptosis of HT1080 cells via GPX4 inhibition and degradation. In summary, our data revealed that the GPX4 degrader 8e achieves better degradation and anti-tumor effects compared to its related GPX4 inhibitor RSL3. Thus, an efficient strategy to induce GPX4 degradation and subsequent ferroptosis was established in this study for malignant cancer treatment in the future.

Nanomedicine and versatile therapies for cancer treatment

The higher prevalence of cancer is related to high rates of mortality and morbidity worldwide. By virtue of the properties of matter at the nanoscale, nanomedicine is proven to be a powerful tool to develop innovative drug carriers with greater efficacies and fewer side effects than conventional therapies. In this review, different nanocarriers for controlled drug release and their routes of administration have been discussed in detail, especially for cancer treatment. Special emphasis has been given on the design of drug delivery vehicles for sustained release and specific application methods for targeted delivery to the affected areas. Different polymeric vehicles designed for the delivery of chemotherapeutics have been discussed, including graft copolymers, liposomes, hydrogels, dendrimers, micelles, and nanoparticles. Furthermore, the effect of dimensional properties on chemotherapy is vividly described. Another integral section of the review focuses on the modes of administration of nanomedicines and emerging therapies, such as photothermal, photodynamic, immunotherapy, chemodynamic, and gas therapy, for cancer treatment. The properties, therapeutic value, advantages, and limitations of these nanomedicines are highlighted, with a focus on their increased performance versus conventional molecular anticancer therapies.

All-stage targeted therapy for glioblastoma based on lipid membrane coated cabazitaxel nanocrystals

Glioblastoma (GBM) is the most aggressive brain tumor with poor prognosis and frequent recurrence. The blood-brain barrier (BBB), blood-brain tumor barrier (BBTB) hinder the entry of therapeutics into the glioma region. Vasculogenic mimicry (VM) formed by invasive glioma cells is also related to recurrence of GBM. VAP is a D-peptide ligand of GRP78 protein overexpressed on BBTB, VM, and glioma cells but not on normal tissues. Besides, p-hydroxybenzoic acid (pHA) can effectively traverse the BBB. Herein we developed an all-stage glioma-targeted cabazitaxel (CBZ) nanocrystal loaded liposome modified with a "Y" shaped targeting ligand composed of pHA and VAP (pV-Lip/cNC). The pure drug nanocrystal core provided high drug loading, while lipid membrane promoted the stability and circulation time. pV-Lip/cNC exhibited excellent glioma homing, barriers crossing, and tumor spheroid penetrating capability in vitro. Treatment of pV-Lip/cNC displayed enhanced CBZ accumulation in glioma and anti-glioma effect with a median survival time (53 days) significantly longer than that of cNC loaded liposomes modified with either single ligand (42 days for VAP and 45 days for pHA) in the murine orthotopic GBM model. These results indicated pV-Lip/cNC could traverse the BBB and BBTB, destruct VM, and finally kill glioma cells to realize all-stage glioma therapy.

Synthesis, cytotoxicity assay, pharmacokinetics, biodistribution and modeling study of cabazitaxel-dextran nanoconjugates: targeted vs non targeted delivery

Cabazitaxel (CTX) is an anti-neoplastic agent of second-generation taxane derivatives, characterized by very low water solubility. The currently marketed formulation of CTX contains high concentrations of surfactant and ethanol, which causes severe hypersensitivity reactions in patients. To deal with aforementioned side effects, our previous study attempted to develop the prodrugs of CTX with dextran. Here our approach differs through synthesizing folate containing prodrug and also investigating cytotoxicity and pharmacokinetics parameters obtained with dextran and dextran-folate nanoconjugates versus free CTX. MCF-7 with medium folate receptor expression and MDA-MB-231 as high folate receptor expression cell lines were selected for cytotoxicity assay. Pharmacokinetics properties were studied by injecting prodrugs and CTX to Wistar rats, analyzing serum and selected tissue samples and the obtained results were sibjected to data modeling study. The size of synthesized prodrugs was mostly less than 90 nm. Folate conjugates provided higher toxicity in comparison with dextran conjugates on both cell lines. In vivo non-compartmental pharmacokinetics analysis revealed enhanced area under the curve (about 3-5 fold for different samples) and longer half-life (approximately 1.3-1.8 fold higher) which led to increased serum residence time of prodrugs in comparison to free CTX. Tissue accumulation data showed that liver was the major organ with high accumulation of CTX. The accumulation of folate conjugates was remarkably higher than dextran samples (p < 0.05 in samples of 2, 10 and 24 h). Data modeling by Principal Component Analysis (PCA) and Hierarchical Cluster models showed a significant difference between pharmacokinetics properties of CTX and prodrugs. In summary, prodrugs seem to be proper and promising CTX delivery systems as substitution for the current market formulation.

Self-Assembled pH-Sensitive Polymeric Nanoparticles for the Inflammation-Targeted Delivery of Cu/Zn-Superoxide Dismutase

The use of superoxide dismutase (SOD) is currently limited by its short half-life, rapid plasma clearance rate, and instability. We synthesized a small library of biofriendly amphiphilic polymers that comprise methoxy poly(ethylene glycol)-poly(cyclohexane-1,4-diyl acetone dimethyleneketal) (mPEG-PCADK) and mPEG-poly((cyclohexane_86.7%, 1,5-pentanediol_13.3%)-1,4-diyl acetone dimethylene ketal) (PK3) for the targeted delivery of SOD. The novel polymers could self-assemble into micellar nanoparticles with favorable hydrolysis kinetics, biocompatibility, long circulation time, and inflammation-targeting effects. These materials generated a better pH-response curve and exhibited better hydrolytic kinetic behavior than PCADK and PK3. The polymers showed good biocompatibility with protein drugs and did not induce an acidic microenvironment during degradation in contrast to materials such as PEG-block-poly(lactic-co-glycolic acid) (PLGA) and PLGA. The SOD that contained reverse micelles based on mPEG2000-PCADK exhibited good circulation and inflammation-targeting properties. Pharmacodynamic results indicated exceptional antioxidant and anti-inflammatory activities in a rat adjuvant-induced arthritis model and a rat peritonitis model. These results suggest that these copolymers are ideal protein carriers for targeting inflammation treatment.

Recent progress in nanoformulations of cabazitaxel

The antitumor efficacy of various paclitaxel (PTX) and docetaxel (DTX) formulations in clinical applications is seriously affected by drug resistance. Cabazitaxel, a second-generation taxane, exhibits greater anticancer activity than paclitaxel and docetaxel and has low affinity for the P-glycoprotein (P-gp) efflux pump because of its structure. Therefore, cabazitaxel has the potential to overcome taxane resistance. However, owing to the high systemic toxicity and hydrophobicity of cabazitaxel and the instability of its commercial preparation, Jevtana®, the clinical use of cabazitaxel is restricted to patients with metastatic castration-resistant prostate cancer (mCRPC) who show progression after docetaxel-based chemotherapy. Nanomedicine is expected to overcome the limitations associated with cabazitaxel application and surmount taxane resistance. This review outlines the drug delivery systems of cabazitaxel published in recent years, summarizes the challenges faced in the development of cabazitaxel nanoformulations, and proposes strategies to overcome these challenges.

Development, optimization and in vitro evaluation of oxaliplatin loaded nanoparticles in non-small cell lung cancer

BACKGROUND

Platinum-based chemotherapy in non-small cell lung cancer (NSCLC) has been demonstrated as a promising approach by many researchers. However, due to low bioavailability and several side effects, drug targeting to lungs by intravenous administration is not a common route of administration.

OBJECTIVE

In this study, oxaliplatin loaded polycaprolactone (PCL) nanoparticles were prepared to overcome the limitations of the drug. 3³ factorial design was used to evaluate the combined effect of the selected variables on the nanoparticle characteristics and to optimize oxaliplatin loaded PCL nanoparticles.

METHODS

The factorial design was used to study the influence of three different independent variables on the response of nanoparticle particle size, polydispersity index (PDI), zeta potential, and encapsulation efficiency. The cellular uptakes of oxaliplatin loaded nanoparticles with different molecular weights of PCL were evaluated. Moreover, optimized nanoparticles were evaluated for their efficacy in non-small lung cancer using the SK-MES-1 cell line.

RESULTS

In factorial design, it is found that the homogenization speed and surfactant ratio represented the main factors influencing particle size and PDI and did not seem to depend on the PCL ratio. While the cytotoxicity of free oxaliplatin and oxaliplatin loaded nanoparticles were similar in low drug doses (2.5 and 25 μg/mL), the cytotoxicity of oxaliplatin loaded nanoparticles on SK-MES-1 cell was found higher in higher doses (p < 0.05). Moreover, oxaliplatin nanoparticles formulated with different molecular weights of PCL did not show significant differences in cellular uptake in 1 h and 2 h. However, the uptake of PCL₈₀₀₀₀ NPs was found significantly greater than free oxaliplatin at 4 h (p < 0.05).

CONCLUSION

Hence, the development of oxaliplatin loaded PCL nanoparticles can be a useful approach for effective NSCLC therapy. Development, optimization and in vitro evaluation of oxaliplatin loaded nanoparticles in non-small cell lung cancer.

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

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

Nose-to-Brain Delivery of Cancer-Targeting Paclitaxel-Loaded Nanoparticles Potentiates Antitumor Effects in Malignant Glioblastoma

Glioblastoma multiforme (GBM) is an aggressive tumor with no curative treatment. The tumor recurrence after resection often requires chemotherapy or radiation to delay the infiltration of tumor remnants. Intracerebral chemotherapies are preferentially being used to prevent tumor regrowth, but treatments remain unsuccessful because of the poor drug distribution in the brain. In this study, we investigated the therapeutic efficacy of cancer-targeting arginyl-glycyl-aspartic tripeptide (RGD) conjugated paclitaxel (PTX)-loaded nanoparticles (NPs) against GBM by nose-to-brain delivery. Our results demonstrated that RGD-modified PTX-loaded NPs showed cancer-specific delivery and enhanced anticancer effects in vivo. The intranasal (IN) inoculation of RGD-PTX-loaded NPs effectively controls the tumor burden (75 ± 12% reduction) by inducing apoptosis and/or inhibiting cancer cell proliferation without affecting the G₀ stage of normal brain cells. Our data provide therapeutic evidence supporting the use of intranasally delivered cancer-targeted PTX-loaded NPs for GBM therapy.

NIR/Thermoresponsive Injectable Self-Healing Hydrogels Containing Polydopamine Nanoparticles for Efficient Synergistic Cancer Thermochemotherapy

Injectable and self-healing hydrogels with thermoresponsiveness as smart hydrogels displayed injectability, automatic healing, and phase and volume changes as well. Here, the thermoresponsive self-healing hydrogel was prepared via the formation of dynamic covalent enamine bonds between the amino groups in polyetherimide (PEI) and the acetoacetate groups in the four-armed star-shaped poly(2-(dimethylamino)ethyl methacrylate-co-2-hydroxyethyl methacrylate) modified with tert-butyl acetoacetate (t-BAA), SP(DMAEMA-co-HEMA-AA). After adding polydopamine nanoparticles (PDA NPs), the SP(DMAEMA-co-HEMA-AA)/PEI/PDA-NP nanocomposite hydrogel presented phase change and volume shrinkage under near-infrared (NIR) irradiation. The thermoresponsive nanocomposite hydrogel loaded with the anticancer drug doxorubicin (DOX) could be injected into the 4T1 tumor by intratumoral injection. After NIR laser irradiation, the temperature of the hydrogel increased because of the photothermal effect of PDA NPs inducing local hyperthermia. Because the hydrophilicity-hydrophobicity transition of the hydrogel occurred, DOX molecules were squeezed out from the hydrogel at temperatures higher than its lower critical solution temperature (LCST) and the tumor cells suffered from internal stress from the shrunk hydrogel. The injectable nanocomposite hydrogel not only demonstrated the synergism of highly efficient thermochemotherapy but also showed the function of improving drug utilization and precise treatment to reduce the side effects of drugs.

Cabazitaxel-Loaded Nanocarriers for Cancer Therapy with Reduced Side Effects

Jevtana^® is a micellar cabazitaxel (CBZ) solution that was approved for prostate cancer in 2010, and recently, this drug has been reported for breast cancer. The purpose of this study is to evaluate the mediated delivery of CBZ via liposomes and nanoparticles (NPs) for the treatment of breast cancer and compare these with a micellar formulation that is currently in clinical use. CBZ-loaded nanocarriers were prepared with particle sizes between 70–110 nm, and with the sustained in vitro release of CBZ for more than 28 days. Cytotoxicity studies on MCF-7 and MDA-MB-231 cells demonstrated the toxic potential of these nanocarriers. Cellular internalization revealed that NPs and liposomes have better permeability than micelles. Cell cycle analysis and apoptosis studies on MCF-7 and MDA-MB-231 cells confirmed G2/M phase arrest as well as cell death due to apoptosis and necrosis, where formulations were found to be effective compared to a micellar CBZ solution. Results from pharmacokinetic studies revealed that there is an increased circulation half-life and mean residence time for CBZ liposomes and NPs in comparison with a micellar CBZ solution. CBZ liposomes and NPs showed a reduction in hemolysis and neutropenia in comparison with a micellar CBZ solution in rats.

Nano-carriers for drug routeing - towards a new era

The objective of this article is to propose a re-visiting of the paradigms of nano-carriers based drug routeing from an industrial viewpoint. The accumulation of drugs in specific body compartments after intravenous administration and the improvement of the oral bioavailability of peptides were taken as examples to propose an update of the translational framework preceding industrialisation. In addition to the recent advances on the biopharmacy of nano-carriers, the evolution of adjacent disciplines such as the biology of diseases, the chemistry of polymers, lipids and conjugates, the physico-chemistry of colloids and the assembling of materials at the nanoscale (referred to as microfluidics) are taken into account to consider new avenues in the applications of drug nano-carriers. The deeper integration of the properties of the drug and of the nano-carrier, in the specific context of the disease, advocates for product oriented programmes. At the same time, the advent of powerful collaborative digital tools makes possible the extension of the expertise spectrum. In this open-innovation framework, the Technology Readiness Levels (TRLs) of nano-carriers are proposed as a roadmap for the translational process from the Research stage to the Proof-of-Concept in human.

Polymer nanoparticles for the intravenous delivery of anticancer drugs: the checkpoints on the road from the synthesis to clinical translation

In this review article we discuss some of the key aspects concerning the development of a polymer-based nanoparticle formulation for intravenous drug delivery. Since numerous preparations fail before and during clinical trials, our aim is to emphasize the main issues that a nanocarrier has to face once injected into the body. These include biocompatibility and toxicity, drug loading and release, nanoparticle storage and stability, biodistribution, selectivity towards the target organs or tissues, internalization in cells and biodegradability. They represent the main checkpoints to define a polymer-based formulation as safe and effective. Indeed, this review is intended to provide guidelines to be followed in the early development of a new nanotherapeutic to hopefully increase the success rate of polymer-based formulations entering clinical trials. The corresponding requirements and characteristics are discussed in the context of some relevant case studies taken from the literature and mainly related to the delivery of lipophilic anticancer therapeutics.

Synthesis, Biological Evaluation and Low-Toxic Formulation Development of Glycosylated Paclitaxel Prodrugs

Paclitaxel (PTX) is a famous anti-cancer drug with poor aqueous solubility. In clinical practices, Cremophor EL (polyethoxylated castor oil), a toxic surfactant, is used for dissolution of PTX, which accounts for serious side effects. In the present study, a single glucose-conjugated PTX prodrug (SG-PTX) and a double glucose-conjugated PTX prodrug (DG-PTX) were synthesized with a glycosylated strategy via succinate linkers. Both of the two prodrugs presented significant solubility improvement and drug-like lipophilicities. Compared to DG-PTX, SG-PTX manifested more promising release of the parent drug in serum. A high percentage of PTX released from SG-PTX could be detected after enzymatic hydrolysis of β-glucuronidase. Besides, both of the two prodrugs exhibited effective cytotoxicity against breast cancer cells and ovarian cancer cells, but presented reduced cytotoxicity against normal breast cells. Moreover, SG-PTX manifested impressive solubility in a low toxic formulation (without ethanol) with a different percentage of Cremophor EL. These results indicated that glycosylation is a promising strategy for PTX modification and SG-PTX may be a feasible and potential type of PTX prodrug. In addition, ethanol-free formulation with a low percentage of Cremophor EL might have the potential to develop a safer formulation for further studies of glycosylated PTX prodrugs.

Cabazitaxel and thymoquinone co-loaded lipospheres as a synergistic combination for breast cancer

Cabazitaxel as microtubule inhibitor and thymoquinone as HDAC inhibitor affects the important genes like p53, STAT3, Bax, BCL-2, p21 and down regulation of NF-κB are reported for potential activity against breast tumors. However, poor aqueous solubility and permeability hinders the delivery of these drugs to target site. To address the delivery challenges cabazitaxel and thymoquinone co-loaded lipospheres were developed. Lipospheres are the lipid based self-assemblies of particle size below 150 nm were prepared with more than 90% entrapment efficiency for both the drugs. In vitro drug release studies revealed there was a sustained diffusion controlled drug release from liposphere matrix leading to decrease in particle size with increase in zeta potential. Cytotoxicity studies on MCF-7 and MDA-MB-231 cells demonstrated cabazitaxel and thymoquinone as synergistic combination for the treatment of breast cancer which was proved by CompuSyn software. Enhanced efficacy of developed lipospheres can be due to rapid cellular internalization which was observed in confocal laser scanning microscopy. Drastic changes in cancer cell morphology such as nuclear fragmentation were observed upon treatment with these lipospheres in comparison to combination solution as observed in fluorescent imaging which are the hall marks of apoptosis. Cell cycle analysis and apoptosis studies confirmed the increased Sub G1 phase arrest as well as cell death due to apoptosis. Thus, as per observed results, it can be concluded that cabazitaxel and thymoquinone co-loaded lipospheres are the efficient delivery vehicles in management of breast cancer.

Drug-Polymer Interaction, Pharmacokinetics and Antitumor Effect of PEG-PLA/Taxane Derivative TM-2 Micelles for Intravenous Drug Delivery

PURPOSE

A novel polymer micelle was prepared with a high drug loading, good stability, high tolerance and better anti-tumor effect.

METHODS

TM-2 was encapsulated in poly-block-poly (D, L-lactic acid) self-assembled micelles by the thin-film hydration method. From the critical micelle concentrations of the copolymers, particle size, drug loading and encapsulation efficiency of drug-loading micelles, the appropriate polymer material could be assessed. Comparisons between TM-2 solution and TM-2 micelles were done to evaluate the pharmacokinetics and toxicity in rats, compared with Taxol to evaluate the anti-tumor effect in mice.

RESULTS

The optimized TM-2 micelles achieved a high drug loading (~20%) with the polymer material of PEG_2k-PLA_2.5k, with a particle size of 30 nm and no significant change in particle size after lyophilization. The result of pharmacokinetic experiment displayed that the half-life in vivo was obviously prolonged. The maximum tolerated dose of TM-2 micelles was approximately 25 mg/kg in rats, and the relative tumor growth rate of Taxol (15 mg/kg), TM-2 (10 mg/kg), TM-2 (15 mg/kg) and TM-2 (40 mg/kg) in mice were 49.35%, 49.14%, 36.44 and 9.98% respectively.

CONCLUSIONS

TM-2 micelles with high drug loading increased drug solubility, improved tolerance, antitumor effects and reduced toxicity.

Docetaxel-Loaded Hyaluronic Acid-Cathepsin B-Cleavable-Peptide-Gold Nanoparticles for the Treatment of Cancer

Gold nanoparticles are commonly used for medical applications such as drug delivery and as therapeutic and diagnostic materials because of their unique properties. In this study, we prepared docetaxel (DTX)-loaded hyaluronic acid-cleavable-peptide-gold nanoparticles for the treatment of cancer by selectively delivering DTX into the tumor and, thus, enhancing the therapeutic effect of DTX; further, we determined synergistic effects of the nanoparticles using laser treatment. The DTX-loaded hyaluronic acid-cleavable-peptide-gold nanoparticles prepared in this study had an average size of 75 nm and negative surface charge. The nanoparticles revealed greater cytotoxicity and higher tumor suppression efficacy in tumor models than free DTX under near-infrared laser irradiation. Therefore, the nanoparticle formulation prepared in this study could be utilized for targeted drug delivery and in combination with other cancer therapies.

The current understanding of mesenchymal stem cells as potential attenuators of chemotherapy-induced toxicity

Chemotherapeutic agents are part of the standard treatment algorithms for many malignancies; however, their application and dosage are limited by their toxic effects to normal tissues. Chemotherapy-induced toxicities can be long-lasting and may be incompletely reversible; therefore, causative therapies for chemotherapy-dependent side effects are needed, especially considering the increasing survival rates of treated cancer patients. Mesenchymal stem cells (MSCs) have been shown to exhibit regenerative abilities for various forms of tissue damage. Preclinical data suggest that MSCs may also help to alleviate tissue lesions caused by chemotherapeutic agents, mainly by establishing a protective microenvironment for functional cells. Due to the systemic administration of most anticancer agents, the effects of these drugs on the MSCs themselves are of crucial importance to use stem cell-based approaches for the treatment of chemotherapy-induced tissue toxicities. Here, we present a concise review of the published data regarding the influence of various classes of chemotherapeutic agents on the survival, stem cell characteristics and physiological functions of MSCs. Molecular mechanisms underlying the effects are outlined, and resulting challenges of MSC-based treatments for chemotherapy-induced tissue injuries are discussed.

PEGylated lipid microspheres loaded with cabazitaxel for intravenous administration: stability, bioavailability, antitumor efficacy, and toxicity

This paper aimed to develop a novel lipid microsphere delivering cabazitaxel (CTX) using phosphatidylcholine combined with DSPE-PEG2000 as emulsifier, and evaluate its stability, pharmacokinetics, antitumor efficacy, and toxicity. The pegylated cabazitaxel-loaded lipid microspheres (CTX-PLMs) were prepared by high-pressure homogenization methods; the biological samples were analyzed by the UPLC-MS/MS method. CTX-PLMs had a drug concentration of 1.2 mg/ml and a mean particle size of 180.0 ± 51.119 nm. CTX-PLMs showed a superior physical stability as it could remain nearly intact after 1-year storage. The AUC_0-t of the CTX-PLMs was 1562.6 ± 520.1 μg h L^-1 compared with the CTX-solution of 860.734 ± 312.4 μg h L^-1. CTX-PLMs exhibited a strong antitumor efficacy against NCI-N87 and DU145 tumor models with tumor growth inhibition rates of 93.5 and 88.5%, respectively. The LD50 of CTX-PLMs in rats was 20.89 mg/kg. As for the long-term toxicity, the thymus, mesenteric lymph nodes, and bone marrow were the main toxic target organs and systemic toxicity induced by CTX-PLMs was alleviated relative to that of the CTX-solution. Safety assessment studies including hemolysis test, dermal sensitization test, systemic anaphylaxis, and vascular stimulation test indicated that CTX-PLMs is safe enough for intravenous administration. In a word, CTX-PLMs are a promising carrier for intravenous administration with satisfactory stability, stronger tumor inhibition, and superior safety profile.

Delaying Anticancer Drug Delivery by Self-Assembly and Branching Effects of Minimalist Dendron-Drug Conjugates

Self-assembly of a covalently-bound lipophilic drug to a dendronic scaffold for making organic nanoparticles is reported as a proof of concept in nanovectorization. A minimalist structural approach with a small PEG-dendron conjugated to paclitaxel (PTX), incorporating safe succinic and gallic acids, is efficient to provide the expected anticancer bioactivity, but also significantly retards and targets intracellular delivery of PTX in 2D and 3D lung cancer cell cultures. A branching effect of dendrons is crucial, when compared to linear PTX conjugates. Transmission electron microscopy (TEM) and dynamic light-scattering (DLS) studies indicate the formation of stable, low-disperse nanoparticles at 10^-5  m in H₂ 0, which could also be responsible for the biological effects. An ultrasensitive LC-MS/MS method was used for the determination of intracellular PTX concentration over time, along with the survival rates of cancer cells. Similarly, cell survival assays were successfully correlated to a 3D cell culture with spheroids for mimicking tumors, when treated with PTX conjugates. Our work opens the way to a full evaluation program required for new chemical entities.

Endothelial growth factor receptor-targeted and reactive oxygen species-responsive lung cancer therapy by docetaxel and resveratrol encapsulated lipid-polymer hybrid nanoparticles

Special targeted therapy like endothelial growth factor receptor (EGFR) targeted therapy is available for the treatment of advanced non-small cell lung cancer (NSCLC). Biodegradable core-shell lipid-polymer hybrid nanoparticles (LPNs) can combine the beneficial properties of lipid and polymeric NPs for controlled drug delivery. In the present study, epidermal growth factor (EGF) conjugated LPNs were fabricated to co-deliver docetaxel (DTX) and resveratrol (RSV). In vitro and in vivo studies demonstrated that EGF DTX/RSV LPNs have significant synergistic effects, best tumor inhibition ability and the lowest systemic toxicity. The results indicate that EGF DTX/RSV LPNs may be a promising strategy for treatment of NSCLC.

Ultrasound-induced mild hyperthermia improves the anticancer efficacy of both Taxol® and paclitaxel-loaded nanocapsules

We study the influence of ultrasound on paclitaxel-loaded nanocapsules in vitro and in vivo. These nanocapsules possess a shell of poly(dl-lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) and a liquid core of perfluorooctyl bromide (PFOB). In vitro experiments show that mechanical effects such as cavitation are negligible for nanocapsules due to their small size and thick and rigid shell. As the mechanical effects were unable to increase paclitaxel delivery, we focused on the thermal effects of ultrasound in the in vivo studies. A focused ultrasound sequence was therefore optimized in vivo under magnetic resonance imaging guidance to obtain localized mild hyperthermia with high acoustic pressure. Ultrasound-induced mild hyperthermia (41-43°C) was then tested in vivo in a subcutaneous CT-26 colon cancer murine model. As hyperthermia is applied, an inhibition of tumor growth for both paclitaxel-loaded nanocapsules and the commercial formulation of paclitaxel, namely Taxol® have been observed (p<0.05). Ultrasound-induced mild hyperthermia at high acoustic pressure appears as an interesting strategy to enhance cytotoxic efficacy locally.

Nano-sized cytochrome P450 3A4 inhibitors to block hepatic metabolism of docetaxel

Most drugs are metabolized by hepatic cytochrome P450 3A4 (CYP3A4), resulting in their reduced bioavailability. In this study, we present the design and evaluation of bio-compatible nanocarriers trapping a natural CYP3A4-inhibiting compound. Our aim in using nanocarriers was to target the natural CYP3A4-inhibiting agent to hepatic CYP3A4 and leave drug-metabolizing enzymes in other organs undisturbed. In the design of such nanocarriers, we took advantage of the nonspecific accumulation of small nanoparticles in the liver. Specific targeting functionalization was added to direct nanocarriers toward hepatocytes. Nanocarriers were evaluated in vitro for their CYP3A4 inhibition capacity and in vivo for their biodistribution, and finally injected 24 hours prior to the drug docetaxel, for their ability to improve the efficiency of the drug docetaxel. Nanoparticles of poly(lactic-co-glycolic) acid (PLGA) with a hydrodynamic diameter of 63 nm, functionalized with galactosamine, showed efficient in vitro CYP3A4 inhibition and the highest accumulation in hepatocytes. When compared to docetaxel alone, in nude mice bearing the human breast cancer, MDA-MB-231 model, they significantly improved the delay in tumor growth (treated group versus docetaxel alone, percent treated versus control ratio [%T/C] of 32%) and demonstrated a major improvement in overall survival (survival rate of 67% versus 0% at day 55).

Cholic acid-based novel micellar nanoplatform for delivering FDA-approved taxanes

AIM

To structurally modify our existing cholic acid (CA)-based telodendrimer (TD; PEG^5K-CA₈) for effective micellar nanoencapsulation and delivery of the US FDA-approved members of taxane family.

MATERIALS & METHODS

Generation of hybrid TDs was achieved by replacing four of the eight CAs with biocompatible organic moieties using solution-phase peptide synthesis. Drug loading was done using the standard evaporation method.

RESULTS

Hybrid TDs can generate micelles with narrow size distributions, low critical micelle concentration values (1-6 μM), better hematocompatibility and lack of in vitro cytotoxicity.

CONCLUSION

Along with PEG^5K-CA₈, CA-based hybrid nanoplatform is the first of its kind that can stably encapsulate all three FDA-approved taxanes with nearly 100% efficiency up to 20% (w/w) loading.

Se/Ru-Decorated Porous Metal-Organic Framework Nanoparticles for The Delivery of Pooled siRNAs to Reversing Multidrug Resistance in Taxol-Resistant Breast Cancer Cells

We report here a novel and personalized strategy of selenium/ruthenium nanoparticles modified metal organic frameworks MIL-101(Fe) for delivering pooled small interfering RNAs (siRNAs) to enhance therapy efficacy by silencing multidrug resistance (MDR) genes and interfere with microtubule (MT) dynamics in MCF-7/T (Taxol-resistance) cell. The existence of coordinatively unsaturated metal sites in MIL-101(Fe) can strongly interact with the electron-rich functional groups of cysteine, which can be regarded as the linkage between selenium/ruthenium nanoparticles and MIL-101(Fe). Se@MIL-101 and Ru@MIL-101 loaded with MDR gene-silencing siRNAs via surface coordination can significantly enhance protection of siRNAs against nuclease degradation, increase siRNA cellular uptake, and promote siRNA escape from endosomes/lysosome to silence MDR genes in MCF-7/T cell, resulting in enhanced cytotoxicity through the induction of apoptosis with the signaling pathways of phosphorylation of p53, MAPK, and PI3K/Akt and the dynamic instability of MTs and disrupting normal mitotic spindle formation. Furthermore, in vivo investigation of the nanoparticles on nude mice bearing MCF-7/T cancer xenografts confirmed that Se@MIL-101-(P+V)siRNA nanoparticles can significantly enhance cancer therapeutic efficacy and decrease systemic toxicity in vivo.

Nanoscale isoindigo-carriers: self-assembly and tunable properties

Over the last decade isoindigo derivatives have attracted much attention due to their high potential in pharmacy and in the chemistry of materials. In addition, isoindigo derivatives can be modified to form supramolecular structures with tunable morphologies for the use in drug delivery. Amphiphilic long-chain dialkylated isoindigos have the ability to form stable solid nanoparticles via a simple nanoprecipitation technique. Their self-assembly was investigated using tensiometry, dynamic light scattering, spectrophotometry, and fluorometry. The critical association concentrations and aggregate sizes were measured. The hydrophilic-lipophilic balance of alkylated isoindigo derivatives strongly influences aggregate morphology. In the case of short-chain dialkylated isoindigo derivatives, supramolecular polymers of 200 to 700 nm were formed. For long-chain dialkylated isoindigo derivatives, micellar aggregates of 100 to 200 nm were observed. Using micellar surfactant water-soluble forms of monosubstituted 1-hexadecylisoindigo as well as 1,1'-dimethylisoindigo were prepared for the first time. The formation of mixed micellar structures of different types in micellar anionic surfactant solutions (sodium dodecyl sulfate) was determined. These findings are of practical importance and are of potential interest for the design of drug delivery systems and new nanomaterials.

Building the design, translation and development principles of polymeric nanomedicines using the case of clinically advanced poly(lactide(glycolide))-poly(ethylene glycol) nanotechnology as a model: An industrial viewpoint

The design of the first polymeric nanoparticles could be traced back to the 1970s, and has thereafter received considerable attention, as evidenced by the significant increase of the number of articles and patents in this area. This review article is an attempt to take advantage of the existing literature on the clinically tested and commercialized biodegradable PLA(G)A-PEG nanotechnology as a model to propose quality building and outline translation and development principles for polymeric nano-medicines. We built such an approach from various building blocks including material design, nano-assembly - i.e. physicochemistry of drug/nano-object association in the pharmaceutical process, and release in relevant biological environment - characterization and identification of the quality attributes related to the biopharmaceutical properties. More specifically, as envisaged in a translational approach, the reported data on PLA(G)A-PEG nanotechnology have been structured into packages to evidence the links between the structure, physicochemical properties, and the in vitro and in vivo performances of the nanoparticles. The integration of these bodies of knowledge to build the CMC (Chemistry Manufacturing and Controls) quality management strategy and finally support the translation to proof of concept in human, and anticipation of the industrialization takes into account the specific requirements and biopharmaceutical features attached to the administration route. From this approach, some gaps are identified for the industrial development of such nanotechnology-based products, and the expected improvements are discussed. The viewpoint provided in this article is expected to shed light on design, translation and pharmaceutical development to realize their full potential for future clinical applications.

Macrophages as Active Nanocarriers for Targeted Early and Adjuvant Cancer Chemotherapy

Taking advantage of the highly permeable vasculature and lack of lymphatic drainage in solid tumors (EPR effect), nanosized drug delivery systems or nanomedicines have been extensively explored for tumor-targeted drug delivery. However, in most clinical cases tumors such as the early stage tumors and post-surgery microscopic residual tumors have not yet developed such pathological EPR features, i.e., EPR-deficient. Therefore, nanomedicines may not be applicable for such these tumors. Macrophages by nature can actively home and extravasate through the tight vascular wall into tumors and migrate to their hypoxic regions, and possess perfect stealth ability for long blood circulation and impressive phagocytosis for drug loadings. Thus, nanomedicines loaded in macrophages would harness both merits and gain the active tumor homing capability independent of the EPR effect for treatments of the EPR-deficient tumors. Herein, the critical considerations, current progress, challenges and future prospects of macrophages as carriers for nanomedicines are summarized, aiming at rational design of EPR-independent tumor-targeting active nanomedicines for targeted early and adjuvant cancer chemotherapy.

Cabazitaxel-loaded human serum albumin nanoparticles as a therapeutic agent against prostate cancer

Cabazitaxel-loaded human serum albumin nanoparticles (Cbz-NPs) were synthesized to overcome vehicle-related toxicity of current clinical formulation of the drug based on Tween-80 (Cbz-Tween). A salting-out method was used for NP synthesis that avoids the use of chlorinated organic solvent and is simpler compared to the methods based on emulsion-solvent evaporation. Cbz-NPs had a narrow particle size distribution, suitable drug loading content (4.9%), and superior blood biocompatibility based on in vitro hemolysis assay. Blood circulation, tumor uptake, and antitumor activity of Cbz-NPs were assessed in prostatic cancer xenograft-bearing nude mice. Cbz-NPs exhibited prolonged blood circulation and greater accumulation of Cbz in tumors along with reduced toxicity compared to Cbz-Tween. Moreover, hematoxylin and eosin histopathological staining of organs revealed consistent results. The levels of blood urea nitrogen and serum creatinine in drug-treated mice showed that Cbz-NPs were less toxic than Cbz-Tween to the kidneys. In conclusion, Cbz-NPs provide a promising therapeutic for prostate cancer.

Anti prostate cancer using PEGylated bombesin containing, cabazitaxel loading nano-sized drug delivery system

CONTEXT

Prostate cancer (PCa) is the second most-frequently diagnosed cancer in men. Cabazitaxel was approved for the treatment of patients with hormone-refractory metastatic prostate cancer previously treated with a docetaxel-containing regimen.

OBJECTIVE

In this study, bombesin (BN), a ligand reported to specifically target GRP overexpressing prostate tumor, was applied for the construction of lipid-polymer hybrid nanoparticles (LPNs), and used for the targeted delivery of cabazitaxel (CAB) to prostate cancer.

METHODS

BN-polyethylene glycol-1,2-Distearoyl-sn-glycero-3-phosphoethanolamine (BN-PEG-DSPE) was synthesized. CAB loaded, BN-PEG-DSPE contained LPNs (BN-CAB-LPNs) were prepared. Their particle size, zeta potential and drug encapsulation efficiency (EE) were evaluated. In vitro cytotoxicity study of BN-CAB-LPNs was tested in LNCaP human prostatic cancer cell line (LNCaP cells). In vivo anti-tumor efficacy of the carriers was evaluated on mice bearing prostate cancer model.

RESULTS

The optimum BN-CAB-LPNs formulations had a particle size of 184.9 nm and a 26.5 mV positive surface charge. The growth of LNCaP cells in vitro was obviously inhibited. BN-CAB-LPNs also displayed better anti-tumor activity than the other formulations in vivo.

CONCLUSION

The results demonstrated that BN-CAB-LPNs can sufficiently deliver CAB to the cancer cells and enhance the anti-tumor capacity. Thus, BN-CAB-LPNs can be proved to be a superior nanomedicine which can achieve better therapeutic efficacy of prostate tumor.

Mechanism and kinetics of the loss of poorly soluble drugs from liposomal carriers studied by a novel flow field-flow fractionation-based drug release-/transfer-assay

Liposomes represent a versatile drug formulation approach e.g. for improving the water-solubility of poorly soluble drugs but also to achieve drug targeting and controlled release. For the latter applications it is essential that the drug remains associated with the liposomal carrier during transit in the vascular bed. A range of in vitro test methods has been suggested over the years for prediction of the release of drug from liposomal carriers. The majority of these fail to give a realistic prediction for poorly water-soluble drugs due to the intrinsic tendency of such compounds to remain associated with liposome bilayers even upon extensive dilution. Upon i.v. injection, in contrast, rapid drug loss often occurs due to drug transfer from the liposomal carriers to endogenous lipophilic sinks such as lipoproteins, plasma proteins or membranes of red blood cells and endothelial cells. Here we report on the application of a recently introduced in vitro predictive drug transfer assay based on incubation of the liposomal drug carrier with large multilamellar liposomes, the latter serving as a biomimetic model sink, using flow field-flow fractionation as a tool to separate the two types of liposomes. By quantifying the amount of drug remaining associated with the liposomal drug carrier as well as that transferred to the acceptor liposomes at distinct times of incubation, both the kinetics of drug transfer and release to the water phase could be established for the model drug p-THPP (5,10,15,20-tetrakis(4-hydroxyphenyl)21H,23H-porphine). p-THPP is structurally similar to temoporfin, a photosensitizer which is under clinical evaluation in a liposomal formulation. Mechanistic insights were gained by varying the donor-to-acceptor lipid mass ratio, size and lamellarity of the liposomes. Drug transfer kinetics from one liposome to another was found rate determining as compared to redistribution from the outermost to the inner concentric bilayers, such that the overall process could be adequately described by a single 1st order kinetic model. By varying the donor-to-acceptor lipid mass ratio in the range 1:1 to 1:10, a correlation was established between donor-to-acceptor-lipid mass ratio and transfer kinetics, which is regarded essential for scaling to physiological lipid mass ratios. By applying the assay to a series of structurally related model compounds of different bilayer affinity, transfer and release kinetics were established over the whole expected range of liposome bilayer associated drugs in terms of water solubility and lipophilicity. A very rapid transfer and considerable release from liposomes to the water phase was observed for the more water-soluble compounds Sudan II (clogP 5.45) and Sudan III (clogP 6.83). For the more lipophilic compounds, the rate of transfer from the donor liposomes followed the rank order Sudan IV (fastest)>Oil Red O>Sudan Black>p-THPP (slowest). For an equimolar donor-to-acceptor lipid mass ratio, half-lifes of transfer in the range of 12min (Sudan IV) up to 1.5h (p-THPP) were determined. In essence, the results presented here allow for both, mechanistic insights and predictions of drug loss from liposomal carriers upon exposure to biological sinks, which appear more realistic than the commonly employed in vitro release tests.

Nanotechnology for the delivery of phytochemicals in cancer therapy

The aim of this review is to summarize advances that have been made in the delivery of phytochemicals for cancer therapy by the use of nanotechnology. Over recent decades, much research effort has been invested in developing phytochemicals as cancer therapeutic agents. However, several impediments to their wide spread use as drugs still have to be overcome. Among these are low solubility, poor penetration into cells, high hepatic disposition, and narrow therapeutic index. Rapid clearance or uptake by normal tissues and wide tissue distribution result in low drug accumulation in the target tumor sites can result in undesired drug exposure in normal tissues. Association with or encapsulation in nanoscale drug carriers is a potential strategy to address these problems. This review discussed lessons learned on the use of nanotechnology for delivery of phytochemicals that been tested in clinical trials or are moving towards the clinic.