A review of the ligands and related targeting strategies for active targeting of paclitaxel to tumours

Biochemical hallmarks-targeting antineoplastic nanotherapeutics

Tumor microenvironments (TMEs) have received increasing attention in recent years as they play pivotal roles in tumorigenesis, progression, metastases, and resistance to the traditional modalities of cancer therapy like chemotherapy. With the rapid development of nanotechnology, effective antineoplastic nanotherapeutics targeting the aberrant hallmarks of TMEs have been proposed. The appropriate design and fabrication endow nanomedicines with the abilities for active targeting, TMEs-responsiveness, and optimization of physicochemical properties of tumors, thereby overcoming transport barriers and significantly improving antineoplastic therapeutic benefits. This review begins with the origins and characteristics of TMEs and discusses the latest strategies for modulating the TMEs by focusing on the regulation of biochemical microenvironments, such as tumor acidosis, hypoxia, and dysregulated metabolism. Finally, this review summarizes the challenges in the development of smart anti-cancer nanotherapeutics for TME modulation and examines the promising strategies for combination therapies with traditional treatments for further clinical translation.

Current Trends and Prospects for Application of Green Synthesized Metal Nanoparticles in Cancer and COVID-19 Therapies

Cancer and COVID-19 have been deemed as world health concerns due to the millions of lives that they have claimed over the years. Extensive efforts have been made to develop sophisticated, site-specific, and safe strategies that can effectively diagnose, prevent, manage, and treat these diseases. These strategies involve the implementation of metal nanoparticles and metal oxides such as gold, silver, iron oxide, titanium oxide, zinc oxide, and copper oxide, formulated through nanotechnology as alternative anticancer or antiviral therapeutics or drug delivery systems. This review provides a perspective on metal nanoparticles and their potential application in cancer and COVID-19 treatments. The data of published studies were critically analysed to expose the potential therapeutic relevance of green synthesized metal nanoparticles in cancer and COVID-19. Although various research reports highlight the great potential of metal and metal oxide nanoparticles as alternative nanotherapeutics, issues of nanotoxicity, complex methods of preparation, biodegradability, and clearance are lingering challenges for the successful clinical application of the NPs. Thus, future innovations include fabricating metal nanoparticles with eco-friendly materials, tailor making them with optimal therapeutics for specific disease targeting, and in vitro and in vivo evaluation of safety, therapeutic efficiency, pharmacokinetics, and biodistribution.

Insight on nano drug delivery systems with targeted therapy in treatment of oral cancer

Oral cancer is a type of cancer that develops in the mouth and is one of the deadliest malignancies in the world. Currently surgical, radiation therapy, and chemotherapy are most common treatments. Better treatment and early detection strategies are required. Chemotherapeutic drugs fail frequently due to toxicity and poor tumor targeting. There are high chances of failure of chemotherapeutic drugs due to toxicity. Active, passive, and immunity-targeting techniques are devised for tumor-specific activity. Nanotechnology-based drug delivery systems are the best available solution and important for precise targeting. Nanoparticles, liposomes, exosomes, and cyclodextrins are nano-based carriers for drug delivery. Nanotechnology is being used to develop new techniques such as intratumoral injections, microbubble mediated ultrasonic therapy, phototherapies, and site-specific delivery. This systematic review delves into the details of such targeted and nano-based drug delivery systems in order to improve patient health and survival rates in oral cancer.

Next-Generation Anti-Angiogenic Therapies as a Future Prospect for Glioma Immunotherapy; From Bench to Bedside

Glioblastoma (grade IV glioma) is the most aggressive histopathological subtype of glial tumors with inordinate microvascular proliferation as one of its key pathological features. Extensive angiogenesis in the tumor microenvironment supplies oxygen and nutrients to tumoral cells; retains their survival under hypoxic conditions; and induces an immunosuppressive microenvironment. Anti-angiogenesis therapy for high-grade gliomas has long been studied as an adjuvant immunotherapy strategy to overcome tumor growth. In the current review, we discussed the underlying molecular mechanisms contributing to glioblastoma aberrant angiogenesis. Further, we discussed clinical applications of monoclonal antibodies, tyrosine kinase inhibitors, and aptamers as three major subgroups of anti-angiogenic immunotherapeutics and their limitations. Moreover, we reviewed clinical and preclinical applications of small interfering RNAs (siRNAs) as the next-generation anti-angiogenic therapeutics and summarized their potential advantages and limitations. siRNAs may serve as next-generation anti-angiogenic therapeutics for glioma. Additionally, application of nanoparticles as a delivery vehicle could increase their selectivity and lower their off-target effects.

A β-hairpin peptide with pH-controlled affinity for tumor cells

Considering that the pH in the tumor microenvironment is dysregulated, we designed a β-hairpin peptide (SSRFEWEFESS^DPRGDPSSRFEWEFESS). The configuration of the peptide switched from a flexible linear to a rigid loop structure under weakly acidic conditions. The peptide internalized by tumor cells increased significantly under weakly acidic conditions.

Drug Resistance in Metastatic Breast Cancer: Tumor Targeted Nanomedicine to the Rescue

Breast cancer, specifically metastatic breast, is a leading cause of morbidity and mortality in women. This is mainly due to relapse and reoccurrence of tumor. The primary reason for cancer relapse is the development of multidrug resistance (MDR) hampering the treatment and prognosis. MDR can occur due to a multitude of molecular events, including increased expression of efflux transporters such as P-gp, BCRP, or MRP1; epithelial to mesenchymal transition; and resistance development in breast cancer stem cells. Excessive dose dumping in chemotherapy can cause intrinsic anti-cancer MDR to appear prior to chemotherapy and after the treatment. Hence, novel targeted nanomedicines encapsulating chemotherapeutics and gene therapy products may assist to overcome cancer drug resistance. Targeted nanomedicines offer innovative strategies to overcome the limitations of conventional chemotherapy while permitting enhanced selectivity to cancer cells. Targeted nanotheranostics permit targeted drug release, precise breast cancer diagnosis, and importantly, the ability to overcome MDR. The article discusses various nanomedicines designed to selectively target breast cancer, triple negative breast cancer, and breast cancer stem cells. In addition, the review discusses recent approaches, including combination nanoparticles (NPs), theranostic NPs, and stimuli sensitive or “smart” NPs. Recent innovations in microRNA NPs and personalized medicine NPs are also discussed. Future perspective research for complex targeted and multi-stage responsive nanomedicines for metastatic breast cancer is discussed.

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

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

Knockdown of SERPINE1 reverses resistance of triple‑negative breast cancer to paclitaxel via suppression of VEGFA

Breast cancer (BC) has a poor prognosis and a high number of visceral metastases. Serine protease inhibitor, clade E member 1 (SERPINE1) is a molecule involved in several human malignancies. However, it remains unknown if SERPINE1 plays a role in the development of taxane resistance in TNBC cells. In the present study, the role and mechanism of SERPINE1 in the development of paclitaxel (PTX) resistance in TNBC cells were investigated. A bioinformatics analysis of gene expression profiles in PTX‑resistant cells indicated that SERPINE1 was significantly associated with PTX resistance. Furthermore, the levels of SERPINE1 mRNA and protein were higher in PTX‑resistant cells with respect to those in PTX‑sensitive parent cells. Knockdown of SERPINE1 significantly inhibited cell survival and induced cell apoptosis in vitro. In addition, SERPINE1 silencing led to downregulation of the key angiogenetic vascular endothelial growth factor A (VEGFA). Furthermore, suppression of SERPINE1 markedly attenuated tumor growth in vivo. Collectively, these findings indicated that SERPINE1 significantly contributed to the proliferation and apoptosis of TNBC cells by regulating VEGFA expression. The present study demonstrated SERPINE1 as an oncogene in PTX drug resistance of breast cancer, and revealed that it may serve as a possible target for treating BC.

Biotin-decorated all-HPMA polymeric micelles for paclitaxel delivery

To avoid poly(ethylene glycol)-related issues of nanomedicines such as accelerated blood clearance, fully N-2-hydroxypropyl methacrylamide (HPMAm)-based polymeric micelles decorated with biotin for drug delivery were designed. To this end, a biotin-functionalized chain transfer agent (CTA), 4-cyano-4-[(dodecylsulfanylthiocarbonyl)-sulfanyl]pentanoic acid (biotin-CDTPA), was synthesized for reversible addition-fragmentation chain-transfer (RAFT) polymerization. Amphiphilic poly(N-2-hydroxypropyl methacrylamide)-block-poly(N-2-benzoyloxypropyl methacrylamide) (p(HPMAm)-b-p(HPMAm-Bz)) with molecular weights ranging from 8 to 24 kDa were synthesized using CDTPA or biotin-CDTPA as CTA and 2,2'-azobis(2-methylpropionitrile) as initiator. The copolymers self-assembled in aqueous media into micelles with sizes of 40-90 nm which positively correlated to the chain length of the hydrophobic block in the polymers, whereas the critical micelle concentrations decreased with increasing hydrophobic block length. The polymer with a molecular weight of 22.1 kDa was used to prepare paclitaxel-loaded micelles which had sizes between 61 and 70 nm, and a maximum loading capacity of around 10 wt%. A549 lung cancer cells overexpressing the biotin receptor, internalized the biotin-decorated micelles more efficiently than non-targeted micelles, while very low internalization of both types of micelles by HEK293 human embryonic kidney cells lacking the biotin receptor was observed. As a consequence, the paclitaxel-loaded micelles with biotin decoration exhibited stronger cytotoxicity in A549 cells than non-targeted micelles. Overall, a synthetic pathway to obtain actively targeted poly(ethylene glycol)-free micelles fully based on a poly(HPMAm) backbone was established. These polymeric micelles are promising systems for the delivery of hydrophobic anticancer drugs.

Synergistic Combination of Sodium Aescinate-Stabilized, Polymer-Free, Twin-Like Nanoparticles to Reverse Paclitaxel Resistance

BACKGROUND

The development of paclitaxel (PTX) resistance seriously restricts its clinical efficacy. An attractive option for combating resistance is inhibiting the expression of P-glycoprotein (P-gp) in tumor cells. We have reported that flavokawain A (FKA) inhibited P-gp protein expression in PTX-resistant A549 (A549/T) cells, indicating that FKA combined with PTX may reverse PTX resistance. However, due to the variable pharmacokinetics of FKA and PTX, the conventional cocktail combination in clinics may cause uncertainty of treatment efficacy in vivo.

MATERIALS AND METHODS

To synergistically elevate the anti-cancer activity of PTX and FKA in vivo, the national medical products administration (NMPA) approved sodium aescinate (Aes) was utilized to stabilize hydrophobic PTX and FKA to form polymer-free twin like PTX-A nanoparticles (NPs) and FKA-A NPs.

RESULTS

The resulting nanoparticles prepared simply by nanoprecipitation possessed similar particle size, good stability and ultrahigh drug loadings of up to 50%. With the aid of Aes, these two drugs accumulated in tumor tissue by passive targeting and were efficiently taken up by A549/T cells; this resulted in significant suppression of tumor growth in A549/T homograft mice at a low PTX dose (2.5 mg·kg-1). Synergistic effects and reversed PTX resistance were achieved by the combination of PTX-A NPs and FKA-A NPs by inhibiting P-gp expression in tumor cells.

CONCLUSION

Using NMPA-approved Aes to prepare twin-like nanoparticles without introducing any new materials provides an efficient platform for combination chemotherapy and clinical translation.

Combinatory antitumor therapy by cascade targeting of a single drug

Combination therapy has shown its promise in the clinic for enhancing the efficacy of tumor treatment. However, the dose control of multiple drugs and their non-overlapping toxicity from different drugs are still great challenge. In this work, a single model drug, paclitaxel (PTX), is used to realize combination therapy and solve the problems mentioned above. Either PTX or its triphenylphosphine derivative (TPTX) is encapsulated in galactose-modified liposomes (GLips) to obtain GLips-P or GLips-TP, which are simply mixed in different ratios to finely control the proportion of PTX and TPTX. These mixed liposomes, GLips-P/TP, feature a cascade target delivery of PTX, from tissue to cell, and then to organelle. PTX plays a primary role to cause the cytotoxicity by microtubule bindings in cytoplasm, while TPTX is proved to increase the intracellular levels of caspase-3 and caspase-9 that cause apoptosis via a mitochondria-mediated pathway. Notably, GLips-P/TP 3:1 exhibited the significant drug synergy in both cytotoxicity assay of HepG2 cells and the treatment efficacy in Heps xenograft ICR mouse models. This work not only demonstrates the great promise of a cascade targeting delivery for precise tumor treatment, but also offers a novel platform to design combinatory therapy systems using a single drug.

Axial pharmaceutical properties of liposome in cancer therapy: Recent advances and perspectives

Evaluation of axial properties including preparation, surface functionalization, and pharmacokinetics for delivery of pharmacologically active molecules and genes lead to pharmaceutical development of liposome in cancer therapy. Here, analysis of effects of the axial properties of liposome based on cancer treatment modalities as individually and coherently is vital and shows deserving further investigation for the future. In this review, recent progress in the analysis of preparation approaches, optimizing pharmacokinetic parameters, functionalization and targeting improvement and modulation of biological factors and components resulting in a better function of liposome in cancer for drug/gene delivery and immunotherapy are discussed. Here, recent developments on liposome with vaccines and immunoadjuvant carriers, and antigen-carrier system to cancer immunotherapy are introduced.

Selectivity Enhancement of Paclitaxel Liposome Towards Folate Receptor-Positive Tumor Cells by Ligand Number Optimization Approach

The present work aims to develop folate-targeted paclitaxel liposome (F-PTX-LIP), which will selectively target tumor cells overexpressing folate receptor (FR) and leave normal cells. Liposomes were prepared by thin-film hydration method followed by post-insertion of synthesized ligand 1,2-distearoyl-sn-glycero-phosphoethanolamine-polyethyleneglycol 2000-folic acid (DSPE-PEG2000-FA) on the outer surface of the liposome. The synthesized ligand was evaluated for in vivo acute toxicity in Balb/c mice. Developed liposomal formulations were characterized using transmission electron microscopy (TEM) and small-angle neutron scattering (SANS). We have investigated the effect of ligand number on cell uptake and cytotoxicity by confocal laser scanning microscopy (CLSM), competitive inhibition and 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT) assay. Compared to lung adenocarcinoma cells (A549), uptake in human ovarian carcinoma cells (SKOV3) was 2.2- and 1.2-fold higher for liposome with 480 and 240 ligand number respectively. Competitive inhibition experiment shows that prior incubation of SKOV3 cells with free folic acid significantly reduced the cell uptake of F-PTX-LIP with 480 ligand number (480 F-PTX-LIP) by 2.6-fold. 480 F-PTX-LIP displays higher cytotoxicity than free drug and PTX liposome. Moreover, it specifically targets the cells with higher folate receptor expression. Optimized 480 F-PTX-LIP formulation can be potentially useful for the treatment of folate receptor-positive tumors.

Disruption of mitochondrial membrane potential coupled with alterations in cardiac biomarker expression as early cardiotoxic signatures in human ES cell-derived cardiac cells

Cardiotoxicity is one of the most significant reasons of attrition in drug development. The present study assessed the sensitivity of various endpoints for early monitoring of drug-induced cardiotoxicity using human embryonic stem cell-derived cardiac cells, including precursors as well as mature cardiomyocytes, by correlating changes in cardiac biomarker expression. Directed differentiation was induced and cardiac progenitor cell (CPC) population were treated with cardiotoxic drugs, namely, doxorubicin (Dox) and paclitaxel (Pac), and with noncardiotoxic drug, namely penicillin G. To assess cardiac-specific toxicity, the changes in the expression of key markers of cardiac lineage, such as Nkx2.5, Tbx5, α-myosin heavy chain α-MHC, and cardiac troponin T, were studied using quantitative real-time polymerase chain reaction (qRT-PCR) and flow cytometry (FC). The half-maximal inhibition in the expression of these cardiac markers was analyzed from the dose-response curves. We also assessed the half-maximal inhibition (IC₅₀) in cardiac cells using propidium iodide dye (IC₅₀ PI) and by measuring disruption in the mitochondrial membrane potential (IC₅₀ MMP). We observed that the most sensitive marker was α-MHC in the case of both Dox and Pac, and the order of sensitivity of the various prediction assays was MMP > protein expression by FC > gene expression by qRT-PCR > cell viability by PI staining. The results could enrich the screening of drug-induced cardiotoxicity in vitro and propose disruption in MMP along with downregulation of α-MHC protein as a potential biomarker of predicting cardiotoxicity earlier during drug safety evaluation.

Protein corona variation in nanoparticles revisited: A dynamic grouping strategy

Bio-nano interface investigation models are mainly based on the type of proteins present on corona, bio-nano interaction responses and the evaluation of final outcomes. Due to the extensive diversity in correlative models for investigation of nanoparticles biological responses, a comprehensive model considering different aspects of bio-nano interface from nanoparticles properties to protein corona fingerprints appeared to be essential and cannot be ignored. In order to minimize divergence in studies in the era of bio-nano interface and protein corona with following therapeutic implications, a useful investigation model on the basis of RADAR concept is suggested. The contents of RADAR concept consist of five modules: 1- Reshape of our strategy for synthesis of nanoparticles (NPs), 2- Application of NPs selected based on human fluid, 3- Delivery strategy of NPs selected based on target tissue, 4- Analysis of proteins present on corona using correct procedures and 5- Risk assessment and risk reduction upon the collection and analysis of results to increase drug delivery efficiency and drug efficacy. RADAR grouping strategy for revisiting protein corona phenomenon as a key of success will be discussed with respect to the current state of knowledge.

Novel treatment strategies for patients with HER2-positive breast cancer who do not benefit from current targeted therapy drugs

Human epidermal growth factor receptor-2 positive breast cancer (HER2+ BC) is characterized by a high rate of metastasis and drug resistance. The advent of targeted therapy drugs greatly improves the prognosis of HER2+ BC patients. However, drug resistance or severe side effects have limited the application of targeted therapy drugs. To achieve more effective treatment, considerable research has concentrated on strategies to overcome drug resistance. Abemaciclib (CDK4/6 inhibitor), a new antibody-drug conjugate (ADC), src homology 2 (SH2) containing tyrosine phosphatase-1 (SHP-1) and fatty acid synthase (FASN) have been demonstrated to improve drug resistance. In addition, using an effective vector to accurately deliver drugs to tumors has shown good application prospects. Many studies have also found that natural anti-cancer substances produced effective results during in vitro and in vivo anti-HER2+ BC research. This review aimed to summarize the current status of potential clinical drugs that may benefit HER2+ BC patients in the future.

Coating Matters: Review on Colloidal Stability of Nanoparticles with Biocompatible Coatings in Biological Media, Living Cells and Organisms

Within the last two decades, the field of nanomedicine has not developed as successfully as has widely been hoped for. The main reason for this is the immense complexity of the biological systems, including the physico-chemical properties of the biological fluids as well as the biochemistry and the physiology of living systems. The nanoparticles' physicochemical properties are also highly important. These differ profoundly from those of freshly synthesized particles when applied in biological/living systems as recent research in this field reveals. The physico-chemical properties of nanoparticles are predefined by their structural and functional design (core and coating material) and are highly affected by their interaction with the environment (temperature, pH, salt, proteins, cells). Since the coating material is the first part of the particle to come in contact with the environment, it does not only provide biocompatibility, but also defines the behavior (e.g. colloidal stability) and the fate (degradation, excretion, accumulation) of nanoparticles in the living systems. Hence, the coating matters, particularly for a nanoparticle system for biomedical applications, which has to fulfill its task in the complex environment of biological fluids, cells and organisms. In this review, we evaluate the performance of different coating materials for nanoparticles concerning their ability to provide colloidal stability in biological media and living systems.

Co-delivery of docetaxel and bortezomib based on a targeting nanoplatform for enhancing cancer chemotherapy effects

Using facile polydopamine (PDA)-based surface modification and a pH-sensitive catechol-boronate binding mechanism, a novel drug delivery system was designed for the treatment of breast cancer. The system was able to achieve the following goals: active targeting, pH responsiveness, in vivo blood circulation for a prolonged period of time, and dual drug loading. After coating with PDA, the docetaxel (DTX)-loaded star-shaped copolymer cholic acid-poly(lactide-co-glycolide) nanoparticles (CA-PLGA@PDA/NPs) were functionalized with amino-poly(ethylene glycol)-folic acid (NH2-PEG-FA) and bortezomib (BTZ) to form the targeting composition, DTX-loaded CA-PLGA@PDA-PEG-FA + BTZ/NPs. The novel NPs exhibited similar drug release characteristics compared to unfunctionalized CA-PLGA/NPs. Meanwhile, the incorporated NH2-PEG-FA contributed to active targeting which was illustrated by cellular uptake experiments and biodistribution studies. Moreover, the pH responsive binding between BTZ and PDA was demonstrated to be effective to release BTZ at the tumor acidic environment for synergistic action with DTX. Both in vitro cytotoxicity and in vivo antitumor studies demonstrated that the novel nanoplatform exhibited the most suitable therapeutic effects. Taken together, the versatile PDA modified DTX-loaded CA-PLGA@PDA-PEG-FA + BTZ/NPs offered a promising chemotherapeutic strategy for enhancing breast cancer treatment.

Selenium nanoparticles: potential in cancer gene and drug delivery

In recent decades, colloidal selenium nanoparticles have emerged as exceptional selenium species with reported chemopreventative and therapeutic properties. This has sparked widespread interest in their use as a carrier of therapeutic agents with results displaying synergistic effects of selenium with its therapeutic cargo and improved anticancer activity. Functionalization remains a critical step in selenium nanoparticles' development for application in gene or drug delivery. In this review, we highlight recent developments in the synthesis and functionalization strategies of selenium nanoparticles used in cancer drug and gene delivery systems. We also provide an update of recent preclinical studies utilizing selenium nanoparticles in cancer therapeutics.

Sequence-Defined Oligoamide Drug Conjugates of Pretubulysin and Methotrexate for Folate Receptor Targeted Cancer Therapy

The conjugation of small molecule drugs to ligand containing carrier systems facilitates receptor targeted delivery. The folate receptor (FR) constitutes an ideal target for tumor selective therapy, being overexpressed on several tumor types. It can be targeted using the vitamin folic acid (FolA) or the structurally related drug methotrexate (MTX). Several sequence-defined oligoamides with mono- and multivalent FolA or MTX ligands and an additional thiol conjugation site are synthesized via solid-phase assisted synthesis. Their structure activity relationships are assessed in respect to dihydrofolate reductase inhibition, receptor mediated endocytosis, and cytotoxicity. Then, the tubulin-binding agent pretubulysin (PT), a highly potent drug exhibiting antitumoral, antiangiogenic, and antimetastatic properties, is conjugated via an activated mercaptane derivative to the set of FR-targeting oligoamides. In a combined PT/MTX cytotoxicity study in FR-overexpressing KB and L1210 cells, a 2-arm MTX-PT construct or the 4-arm analog displays the highest potency in the respective cell lines.

A glucose-targeted mixed micellar formulation outperforms Genexol in breast cancer cells

Breast cancer represents the top cancer among women, accounting 521.000 deaths per year. Development of targeted nanomedicines to breast cancer tissues represents a milestone to reduce chemotherapy side effects. Taking advantage of the over-expression of glucose (Glu) membrane transporters in breast cancer cells, we aim to expand the potential of a paclitaxel (PTX)-loaded mixed micellar formulation based on polyvinyl caprolactam-polyvinylacetate-polyethylene glycol graft copolymer (Soluplus®) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) by its surface decoration with Glu moieties. The glycopolymer (Soluplus(Glu)) was obtained by microwave-assisted ring opening reaction of δ-gluconolactone initiated by Soluplus®. The glycosylation was confirmed by ¹H NMR and by agglutination assays employing Concanavalin A. The hydrodynamic diameter of Soluplus(Glu) micelles was characterized by dynamic light scattering (100.3±3.8nm) as well as the critical micellar concentration value (0.0151% w/v). Then, a mixed micelle formulation employing Soluplus®, Soluplus(Glu) and TPGS (3:1:1wt ratio) loaded with PTX (4mg/mL) was developed as a multifunctional nanocarrier. Its in vitro anticancer performance in MCF-7 (1.6-fold) and MDA-MB-231 (14.1-fold) was significantly enhanced (p<0.05) versus the unique commercially available micellar-based PTX-nanoformulation (Genexol®). Furthermore, the in vitro PTX cellular uptake assays revealed that the drug intracellular/cell content was significantly (p<0.05) higher for the Glu-containing mixed micelles versus Genexol® after 6h of incubation with MCF-7 (30.5-fold) and MDA-MB-231 (5-fold). Overall, results confirmed the potential of our Glu-decorated mixed colloidal formulation as an intelligent nanocarrier for PTX-targeted breast cancer chemotherapy.

Rapid delivery of paclitaxel with an organic solvent-free system based on a novel cell penetrating peptide for suppression of tumor growth

PTX is rapidly translocated into HeLa cells with the help of R7. The intracellular PTX concentration of R7/PTX complex group is 3 fold that of the free PTX group. This delivery system does not contain any organic solvent. The tumor growth is significantly suppressed by a tail vein injection of the R7/PTX complex.

Effect of a paclitaxel-eluting metallic stent on rabbit esophagus

The use of self-expanding metallic stents (SEMS) is the current treatment of choice for malignant gastrointestinal obstructions. A paclitaxel-eluting metallic SEMS (PEMS) may have an antitumor effect on esophageal tissue. PEMS with 10% paclitaxel or conventional SEMS were inserted into the lower esophagus of rabbits. Following the insertion of the stents for 1, 2, 4 and 6 weeks, the rabbits were sacrificed and the status of the stent insertion was examined, as well as any macroscopic or microscopic mucosal changes in the esophageal tissue. All the rabbits survived until death without any complications. No migration following stent insertion occurred. The number of cases with proximal obstruction increased in a time-dependent manner, and no significant difference was observed between the two groups. Gross histological examination showed similar tissue reaction to the stents at 1, 2 and 4 weeks, and inflammatory cell infiltrating was higher in the SEMS group at 1 and 2 weeks. However, inflammatory cell infiltration was markedly higher in the PEMS group at 4 and 6 weeks. Food-intake and weight were similar in the two groups. The results of the present study demonstrated that PEMS may serve as a safe alternative treatment strategy for esophageal obstruction. Furthermore, PEMS may inhibit the tumor growth of the esophageal wall through inflammatory infiltration and targeted drug delivery. A tumor model will be required in the future for evaluating the prognosis of patients with advanced esophageal carcinoma.