Lethal Morel-Lavallée lesion: A forensic radiology-pathology correlation

Morel Lavallée lesion or closed degloving injury is normally associated with severe trauma and occurs when the skin and subcutaneous fatty tissue traumatically and abruptly separated from the underlying fascia thus creating a potential space filled with fluid. MVA is the commonest etiology but large or lethal Morel Lavallée is extremely rare. A 35 years old, female pillion rider was involved in a motor vehicle accident and sustained injuries to the left pelvis and thigh. Emergency laparotomy and intra-op abdominal and bilateral lower limb arteriogram revealed no significant finding. Her general condition and vital signs continued to deteriorate despite aggressive resuscitation and eventually died. Post-Mortem Computed Tomography and Post-Mortem Computed Tomography Angiogram was performed and revealed a large cavity in the left thigh suggestive of a lethal Morel Lavallée lesion. Findings were confirmed by conventional autopsy.

Overexpression of paralogues of the wheat expansin gene TaEXPA8 improves low-temperature tolerance in Arabidopsis

Low temperature is one of the important factors limiting wheat yield in cold regions. Expansins are nonenzymatic proteins that loosen cell walls and play important roles in diverse biological processes related to cell wall modification, including development and stress tolerance. Many studies have shown that expansins are involved in resistance to various abiotic stresses, such as heat and drought. However, the role of expansins in response to low-temperature stress remains unclear. Based on our previous transcriptome data of a winter wheat cultivar Dongnongdongmai 2 (DN2), we found that one of the expansin genes, TaEXPA8, was significantly induced by low temperature, indicating a role for TaEXPA8 in cold resistance. In this study, the paralogous TaEXPA8 genes TaEXPA8-A, TaEXPA8-B and TaEXPA8-D were cloned by RT-PCR. These three genes were then transformed into Arabidopsis by the floral dip method. Expression patterns of TaEXPA8 genes in different tissues and in response to several abiotic stresses and hormones were detected by quantitative real-time PCR (qRT-PCR). The results showed that TaEXPA8-A and TaEXPA8-B were expressed mainly in roots, while TaEXPA8-D was expressed predominantly in flowers. TaEXPA8 genes were induced by low-temperature and drought. The overexpression of TaEXPA8-B and TaEXPA8-D enhanced low-temperature resistance and had increased superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activity and soluble protein, MDA and proline content. In summary, our study suggested that the expansins TaEXPA8-B and TaEXPA8-D are involved in the response to low temperature and possibly play a role in cold resistance by activating the protective enzyme system.

Nanomedicine strategies for sustained, controlled and targeted treatment of cancer stem cells

Cancer stem cells (CSCs) are original cancer cells that are of characteristics associated with normal stem cells. CSCs are toughest against various treatments and thus responsible for cancer metastasis and recurrence. Therefore, development of specific and effective treatment of CSCs plays a key role in improving survival and life quality of cancer patients, especially those in the metastatic stage. Nanomedicine strategies, which include prodrugs, micelles, liposomes and nanoparticles of biodegradable polymers, could substantially improve the therapeutic index of conventional therapeutics due to its manner of sustained, controlled and targeted delivery of high transportation efficiency across the cell membrane and low elimination by intracellular autophagy, and thus provide a practical solution to solve the problem encountered in CSCs treatment. This review gives briefly the latest information to summarize the concept, strategies, mechanisms and current status as well as future promises of nanomedicine strategies for treatment of CSCs.

Cationic liposomes induce cell necrosis through lysosomal dysfunction and late-stage autophagic flux inhibition

AIM

The application of cationic liposomes (CLs) as nonviral vectors is hampered by their cellular toxicity. Thus we aim to investigate the mechanisms underlying the cellular toxicity of CLs.

MATERIALS & METHODS

The effect of CLs on the autophagic flux, autophagosome-lysosome fusion, lysosome membrane permeabilization and cell necrosis of liver cells was investigated.

RESULTS & CONCLUSION

Our results reveal a novel mechanism of CL-induced cell necrosis involving the induction of lysosome membrane permeabilization and late-stage autophagic flux inhibition that resulted in cytoplasmic release of cathepsin B, mitochondrial dysfunction and reactive oxygen species production, which are the key mediators of cell necrosis. Our study is important for revealing the cellular toxicity of CLs and designing safer gene delivery systems.

Nanocarriers for delivery of siRNA and co-delivery of siRNA and other therapeutic agents

A major problem in cancer treatment is the multidrug resistance. siRNA inhibitors have great advantages to solve the problem, if the bottleneck of their delivery could be well addressed by the various nanocarriers. Moreover, co-delivery of siRNA together with the various anticancer agents in one nanocarrier may maximize their additive or synergistic effect. This review provides a comprehensive summary on the state-of-the-art of the nanocarriers, which may include prodrugs, micelles, liposomes, dendrimers, nanohydrogels, solid lipid nanoparticles, nanoparticles of biodegradable polymers and nucleic acid nanocarriers for delivery of siRNA and co-delivery of siRNA together with anticancer agents with focus on synthesis of the nanocarrier materials, design and characterization, in vitro and in vivo evaluation, and prospect and challenges of nanocarriers.

CD20 Antibody-Conjugated Immunoliposomes for Targeted Chemotherapy of Melanoma Cancer Initiating Cells

Cancer initiating cells (CIC) are tumorigenic cancer cells that have properties similar to normal stem cells. CD20 is a phenotype of melanoma CIC that is responsible for melanoma drug resistance. Vincristine (VCR) is commonly used in melanoma therapy; however, it has been found ineffective against CIC. To target CD20+ melanoma CIC, we prepared VCR-containing immunoliposomes that were conjugated to CD20 antibodies (VCR-Lip-CD20). The drug release profile and the antibody-mediated targeting of the immunoliposomes were optimized to target CD20+ melanoma CIC. The immunoliposomes had desirable particle size (163 nm), drug encapsulation efficiency (91.8%), and drug release profile. We demonstrated that these immunoliposomes could successfully target more than 55% of CD20+ Chinese Hamster Ovary cells (CHO-CD20) even when the CHO-CD20 cells accounted for only 0.1% of a mixed population of CHO-CD20 and CHO cells. After treating WM266-4 melanoma mammospheres for 96 h, the ICo values of the drug delivered in VCR-Lip-CD20, VCR-Lip (VCR liposomes), and VCR were found to be 53.42, 98.99, and 99.09 μg/mL, respectively, suggesting that VCR-Lip-CD20 was 1.85 times more effective than VCR-Lip and VCR. VCR-Lip-CD20 could almost completely remove the tumorigenic ability of WM266-4 mammospheres in vivo, and showed the best therapeutic effect in WM266-4 melanoma xenograft mice. Significantly, VCR-Lip-CD20 could selectively kill CD20+ melanoma CIC in populations of WM266-4 cells both in vitro and in vivo. We demonstrated that VCR-Lip-CD20 has the potential to efficiently target and kill CD20+ melanoma CIC.

Porphine functionalized nanoparticles of star-shaped poly(ε-caprolactone)-b-D-α-tocopheryl polyethylene glycol 1000 succinate biodegradable copolymer for chemophotodynamic therapy on cervical cancer

We developed a system of biodegradable nanoparticles (NPs) of 5,10,15,20-tetrakis(4-aminophenyl)-21H,23H-porphine (TAPP) centered, 4 arm star-shaped copolymers based on poly(ε-caprolactone) (PCL) and D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) for combinatory chemophotodynamic therapy by using docetaxel (DTX) as a model anticancer drug and TAPP as photodynamic sensitizer. TPGS component in the copolymer plays an important role in enhancing the drug encapsulation efficiency, drug release kinetics and cellular uptake of the NPs, as well as in overcoming the multidrug resistance due to inhibition of P-glycoproteins (P-gp) of the cancer cells. We demonstrated in vitro by using the MCF7/ADR breast cancer cells of P-gp overexpression and the HeLa cervical cancer cells that the proposed chemophotodynamic therapy by the DTX-loaded TAPP-PCL-b-TPGS NPs could have much higher therapeutic effect than the original drug Taxotere®. IC50 data showed that the DTX-loaded TAPP-PCL-b-TPGS NPs chemophotodynamic therapy could be 9.36 and 56.5-fold efficient after 24 and 48h treatment, respectively in comparison with the Taxotere® chemotherapy. The in vivo investigation by employing a cervical cancer xenograft model further confirmed the advantages of the proposed chemophotodynamic therapy by the DTX-loaded TAPP-PCL-b-TPGS NPs versus the Taxotere® chemotherapy.

Cancer nanoimmunotherapy using advanced pharmaceutical nanotechnology

Immunotherapy is a promising option for cancer treatment that might cure cancer with fewer side effects by primarily activating the host's immune system. However, the effect of traditional immunotherapy is modest, frequently due to tumor escape and resistance of multiple mechanisms. Pharmaceutical nanotechnology, which is also called cancer nanotechnology or nanomedicine, has provided a practical solution to solve the limitations of traditional immunotherapy. This article reviews the latest developments in immunotherapy and nanomedicine, and illustrates how nanocarriers (including micelles, liposomes, polymer-drug conjugates, solid lipid nanoparticles and biodegradable nanoparticles) could be used for the cellular transfer of immune effectors for active and passive nanoimmunotherapy. The fine engineering of nanocarriers based on the unique features of the tumor microenvironment and extra-/intra-cellular conditions of tumor cells can greatly tip the triangle immunobalance among host, tumor and nanoparticulates in favor of antitumor responses, which shows a promising prospect for nanoimmunotherapy.

Nanotheranostics - application and further development of nanomedicine strategies for advanced theranostics

Nanotheranostics is to apply and further develop nanomedicine strategies for advanced theranostics. This review summarizes the various nanocarriers developed so far in the literature for nanotheranostics, which include polymer conjugations, dendrimers, micelles, liposomes, metal and inorganic nanoparticles, carbon nanotubes, and nanoparticles of biodegradable polymers for sustained, controlled and targeted co-delivery of diagnostic and therapeutic agents for better theranostic effects with fewer side effects. The theranostic nanomedicine can achieve systemic circulation, evade host defenses and deliver the drug and diagnostic agents at the targeted site to diagnose and treat the disease at cellular and molecular level. The therapeutic and diagnostic agents are formulated in nanomedicine as a single theranostic platform, which can then be further conjugated to biological ligand for targeting. Nanotheranostics can also promote stimuli-responsive release, synergetic and combinatory therapy, siRNA co-delivery, multimodality therapies, oral delivery, delivery across the blood-brain barrier as well as escape from intracellular autophagy. The fruition of nanotheranostics will be able to provide personalized therapy with bright prognosis, which makes even the fatal diseases curable or at least treatable at the earliest stage.

Nanoparticles of biodegradable polymers for new-concept chemotherapy

The current regimen of chemotherapy is far from satisfactory--its efficiency is limited and patients suffer from serious side effects. Various drug delivery devices have been under intensive investigation in the past few decades in attempts to develop controlled and targeted methods of chemotherapy administration. This article reviews the latest developments in nanoparticles of biodegradable polymers for chemotherapy of cancer and other diseases such as cardiovascular restenosis. The preliminary results obtained in the author's laboratory are used to demonstrate the concept. This review is written with the belief that engineering, in particular, chemical engineering principles, can be applied and further developed to solve the problems in the current practice of chemotherapy and promote a new concept of chemotherapy - chemotherapy at home.

Pharmaceutical nanotechnology for oral delivery of anticancer drugs

Oral chemotherapy is an important topic in the 21st century medicine, which may radically change the current regimen of chemotherapy and greatly improve the quality of life of the patients. Unfortunately, most anticancer drugs, especially those of high therapeutic efficacy such as paclitaxel and docetaxel, are not orally bioavailable due to the gastrointestinal (GI) drug barrier. The molecular basis of the GI barrier has been found mainly due to the multidrug efflux proteins, i.e. P-type glycoproteins (P-gp), which are rich in the epithelial cell membranes in the GI tract. Medical solution for oral chemotherapy is to apply P-gp inhibitors such as cyclosporine A, which, however, suppress the body's immune system either, thus causing medical complication. Pharmaceutical nanotechnology, which is to apply and further develop nanotechnology to solve the problems in drug delivery, may provide a better solution and thus change the way we make drug and the way we take drug. This review is focused on the problems encountered in oral chemotherapy and the pharmaceutical nanotechnology solutions such as prodrugs, nanoemulsions, dendrimers, micelles, liposomes, solid lipid nanoparticles and nanoparticles of biodegradable polymers. Proof-of-concept in vitro and in vivo results for oral delivery of anticancer drugs by the various nanocarriers, which can be found so far from the literature, are provided.

Targeted co-delivery of docetaxel and siPlk1 by herceptin-conjugated vitamin E TPGS based immunomicelles

We developed a drug delivery system of herceptin-conjugated micelles, which consist of vitamin E TPGS and TPGS-siRNA conjugates, for targeted co-delivery of docetaxel and polo-like kinase 1 siRNA to achieve synergistic effects between the anticancer drug and the small interfering RNA responsible for multidrug resistance. The TPGS-siRNA conjugate is made through disulfide bond that could enable a pH-sensitive intracellular release. The load ratio between siPlk1 and docetaxel could be controlled by adjusting the siPlk1-TPGS to TPGS ratio as well as the drug to polymer ratio. NIH3T3, MCF7, and SK-BR-3 cell lines, which are of low, moderate and high HER2 overexpression, were employed to obtain proof-of-concept experimental results for the advantages of such a design. It has been shown that the IC(50), which is the drug concentration needed to kill 50% of the cancer cells in a designated time period, was 1.72, 0.042, 0.0032 and 0.000671 μg/mL for SK-BR-3 cells after 24 h treatment by Taxotere(®), and docetaxel formulated in the TPGS micelles, the TPGS-siPlk1/TPGS micelles and the herceptin-conjugated TPGS-siPlk1/TPGS micelles, respectively.

Trastuzumab-conjugated vitamin E TPGS liposomes for sustained and targeted delivery of docetaxel

OBJECTIVES

In this study, the authors developed D-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS or simply TPGS) liposomes and further conjugated them to trastuzumab for controlled and targeted delivery of docetaxel (DTX) as a model hydrophobic drug.

METHODS

DTX- or coumarin-6-loaded liposomes were prepared by solvent injection method and characterized for size and size distribution, surface charge, surface chemistry and drug encapsulation efficiency and drug release profile. SK-BR-3 cells were employed as an in vitro model for HER2-positive breast cancer and assessed for their cellular uptake and cytotoxicity of the two liposomal formulations. In vivo pharmacokinetics (PK) was investigated in Sprague-Dawley rats.

RESULTS

The IC(50) value was found to be 20.23 ± 1.95, 3.74 ± 0.98, 0.08 ± 0.4 μg/ml for the marketed preparation of DTX, TPGS liposomes and trastuzumab-conjugated TPGS liposomes, respectively after 24 h incubation with SK-BR-3 cells. In vivo PK experiments showed that i.v. administration of trastuzumab-conjugated liposomes achieved 1.9 and 10 times longer half-life, respectively than PEG-coated liposomes and DTX. The area under the curve (AUC) was increased by 3.47- and 1.728-fold, respectively.

CONCLUSION

The trastuzumab-conjugated vitamin E TPGS-coated liposomes showed greater potential for sustained and targeted chemotherapy in the treatment of HER2 overexpressing breast cancer.

Theranostic liposomes for cancer diagnosis and treatment: current development and pre-clinical success

Liposomes are one of the effective drug delivery systems that are developed based on the nanotechnology concept. Liposomal formulation is the first nanomedicine approved by the US FDA for clinical application. Recently, the marketed liposomes and stealth liposomes have made impact for cancer therapy. In addition, a few receptor-targeted liposome products have been in different phases of clinical trials, which are yet to be marketed. In the present editorial, the advantages of vitamin E TPGS-coated liposomes over the currently available PEG-coated liposomes will be described and their great potentials for nanotheranostics for cancer imaging and therapy will be covered.

Multimodality treatment of cancer with herceptin conjugated, thermomagnetic iron oxides and docetaxel loaded nanoparticles of biodegradable polymers

We developed a system of nanoparticles of poly(lactide)-d-α-tocopheryl polyethylene glycol succinate (PLA-TPGS) and carboxyl group-terminated TPGS (TPGS-COOH) copolymer blend for multimodality treatment of cancer, which formulated docetaxel for chemotherapy, herceptin for biotherapy and targeting, and iron oxides (IOs) for hyperthermia therapy, which are denoted as MMNPs. It is demonstrated that the MMNPs achieved a significantly higher therapeutic effects than the various combination of the corresponding individual modality treatment NPs and the dual modality treatment NPs due to the synergistic effects among the chemo, bio, and thermo therapies. We further developed a method by employing the concept of NPs IC50, the concentration of the agent-, or agents-loaded nanoparticles that is needed to kill 50% of the cancer cells, to quantitatively access the synergistic effects of the multimodality treatment. It is shown by employing the SK-BR-3 cell line as an in vitro model of the HER2-positive breast cancer that the NPs IC50 is 0.42 mg/mL DCL-NPs plus 1.33 mg/mL Her-NPs plus 0.59 mg/mL IOs-NPs, a total NPs concentration of 2.34 mg/mL for the treatment of a physical mixture of the DCL-NPs, Her-NPs and IOs-NPs at the 1:2:7 weight ratio, while it is only 0.0011 mg/mL for the MMNPs for 24 h, which is 2130 fold more efficient than the physical mixture of the corresponding single modality treatments.

Development of docetaxel-loaded vitamin E TPGS micelles: formulation optimization, effects on brain cancer cells and biodistribution in rats

Aim: This work aimed to develop docetaxel-loaded D-α-tocopheryl polyethylene glycol 1000 succinate (vitamin E TPGS or TPGS) micelles for brain cancer chemotherapy by taking advantage of polyethylene glycol for its long half-life in circulation and vitamin E for its high cellular uptake. Material & methods: TPGS micelles containing docetaxel or coumarin-6 were prepared by the solvent casting method and the direct dissolution method at high, moderate and low drug-loading levels. Results & discussion: The particle size of the docetaxel-loaded TPGS micelles ranged between 12 and 14 nm. Docetaxel formulated in the TPGS micelles of high, moderate and low drug-loading levels achieved lower IC50 values compared with Taxotere® after 24-h incubation with C6 glioma brain cancer cells. The TPGS has much lower critical micelle concentration than most phospholipids in micellar formulation, which can be an efficient drug carrier across the blood brain–barrier with high drug encapsulation efficiency, cell uptake, cytotoxicity and desired biodistribution of the formulated drug.

Original submitted: 21 March 2011; Revised submitted: 14th June 2011

Thermochemotherapy mediated by novel solar-planet structured magnetic nanocomposites for glioma treatment

Cancer comprehensive treatment has been fully recognized as it can provide an effective multimodality approach for fighting cancers. This work evaluates the effects of a kind of novel solar-planet structured magnetic nanocomposites (MNCs) for magnetic thermochemotherapy. Amino silane coated magnetic nanoparticles (MNPs) as agent of magnetic mediated hyperthermia (MMH) for cancer treatment were prepared by the chemical precipitation method. Docetaxel (an anticancer drug) loaded polymeric nanoparticles (DNPs) composed of carboxylic-terminated poly (D,L-lactic-co-glycolic acid) (PLGA) with Vitamin E TPGS as emulsifier for sustained drug release were prepared by a modified solvent extraction/evaporation technique. Furthermore, the MNPs modified with amino groups could be covalently attached to the surface of carboxylic terminated DNPs to form the so-called solar-planet structured MNCs by 1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) crosslinking. The prepared solar-planet structure has been confirmed by fluorescent observation. Inductive heating property of the nanocomposite was evaluation by monitoring the temperature increase of the MNCs suspension under alternative magnetic field (AMF). Drug encapsulation efficacy and drug release of the magnetic nanocomposite were conducted by high performance liquid chromatography (HPLC). In vitro evaluation of the novel nanocomposite as mediator for thermochemotherapy was conducted on the U251 human glioma cells and the synergistic effect between MMH and docetaxel chemotherapy was confirmed. All the observation supports that solar-planet structured MNC is a novel and effective mediator for magnetic thermochemotherapy. The MNCs can realize cancer comprehensive treatment thus has great potential in clinical application.

Quantitative control of targeting effect of anticancer drugs formulated by ligand-conjugated nanoparticles of biodegradable copolymer blend

There have been two strategies developed in the recent literature for quantitative control of the targeting effects for drug delivery by ligand-conjugated nanoparticles of biodegradable copolymer blend such as PLGA/PLGA-PEG, i.e. the pre-conjugation strategy and the post-conjugation strategy, in which the ligand conjugation was made before and after the nanoparticle formulation respectively. This research developed another drug delivery system of the PLA-TPGS/TPGS-COOH copolymer blend and further improved the post-conjugation strategy to precisely control the targeting effects by two ways: one is to adjust the PLA-TPGS:TPGS-COOH copolymer blend ratio in the nanoparticle formulation process, which provides a way for coarse control, and another is to control the feeding concentration of the ligand in the herceptin conjugation process, which further provides a fine control. Herceptin conjugation was visualized by the FETEM with immumogold labeling and further quantified by the two techniques, i.e. the Bradford assay and the flow cytometry to confirm each other. The positive correlation between the surface density of the ligand and the cellular internalization as well as the cytotoxicity of the nanoparticle formulations was assessed, which demonstrated that the strategy developed in this research is simple and feasible, which can precisely control the targeting effects of the nanoparticles of biodegradable polymers as well as other nanocarriers such as micelles and liposomes.

Multifunctional silica nanoparticles for targeted delivery of hydrophobic imaging and therapeutic agents

This article reports the development of a multifunctional silica nanoparticle system for targeted delivery of hydrophobic imaging and therapeutic agents. Normally, silica nanoparticles have been widely used to deliver hydrophilic drugs such as doxorubicin while difficult to carry hydrophobic drugs. A strategy for loading hydrophobic drugs onto silica nanoparticles via covalent attachment was developed in this study as a universal strategy to solve this problem. Docetaxel, one of the most potent therapeutics for cancer treatment is selected as a model hydrophobic drug and quantum dots (QDs) are used as a model imaging agent. Such a multifunctional delivery system possesses high drug loading capacity, controlled drug release behavior and stable drug reservation. A mixed layer of polyethylene glycol conjugated phospholipids is formed on the nanoparticle surface to further enhance the biocompatibility and cell fusion capability of the delivery system. Folic acid as ligand is then conjugated onto the surface layer for targeting. Such a multifunctional system for targeting, imaging and therapy is characterized and evaluated in vitro. Fluorescent confocal microscopy is used to monitor the cellular uptake by specific cancer cells. Cytotoxicity studies are conducted by using MTT assay.

Vitamin E TPGS coated liposomes enhanced cellular uptake and cytotoxicity of docetaxel in brain cancer cells

The aim of this work was to develop a drug delivery system of liposomes, which are coated with D-alpha-tocopheryl polyethylene glycol 1000 succinate (TPGS), a PEGylated vitamin E, with docetaxel as a model drug for enhanced treatment of brain tumour in comparison with the nude liposomes as well as with the so-called stealth liposomes, i.e. those coated with polyethylene glycol (PEG), which have been intensive investigated in the literature. Docetaxel or coumarin-6 loaded liposomes were prepared by the solvent injection method and characterized for their particle size, polydispersity, zeta potential and drug encapsulation efficiency. C6 glioma cells were employed as an in vitro model to access cellular uptake and cytotoxicity of the drug or coumarin-6 loaded liposomes. The particle size of the PEG or TPGS coated liposomes was ranged between 126 and 191nm. High-resolution field-emission transmission electron microscopy (FETEM) confirmed the coating of TPGS on the liposomes. The IC50 value, which is the drug concentration needed to kill 50% cells in a designated time period, was found to be 37.04±1.05, 31.04±0.75, 7.70±0.22, and 5.93±0.57μg/ml for the commercial Taxotere(®), the nude, PEG coated and TPGS coated liposomes, respectively after 24h culture with C6 glioma cells. The TPGS coated liposomes showed great advantages in vitro than the PEG coated liposomes.

Herceptin functionalized polyhedral oligomeric silsesquioxane - conjugated oligomers - silica/iron oxide nanoparticles for tumor cell sorting and detection

Sorting and detection of circulating tumor cells (CTC) in peripheral blood as an efficient and non-invasive method to diagnose cancer have recently attracted much attention. In this article, we developed a multiply-engineered nanoparticle system for CTC sorting and detection, which consists of (1) conjugated oligomer (CO) as fluorescence signal source, (2) polyhedral oligomeric silsesquioxanes (POSS) scaffold for CO localization for better fluorescent effects, (3) silica nanoparticles (SiNPs) as formulation matrix of the POSS containing CO, (4) iron oxide (IO) layer on the silica nanoparticles (IO-SiNPs) for magnetic collection, and (5) herceptin surface functionalization of the IO-SiNPs to target cancer cells of HER2 overexpression. Such a multiply-engineered structure can be used for either traditional immunomagnetic methods or microfluidic devices for CTC sorting and detection.

Formulation of Docetaxel by folic acid-conjugated d-α-tocopheryl polyethylene glycol succinate 2000 (Vitamin E TPGS(2k)) micelles for targeted and synergistic chemotherapy

Although high efficacy has been showed, Paclitaxel and Docetaxel cause serious side effects due to the adjuvant used in their clinical formulation Taxol® and Taxotere®. We developed a micelle system with a newly synthesized TPGS(2k) polymer, which shows lower CMC of 0.0219 mg/ml compared with 0.2 mg/ml for traditional micelles with TPGS involved, to achieve sustained and controlled drug delivery with Docetaxel used as a model anti-cancer drug. The TPGS(2k) micelles were further conjugated to folic acid (FA) for targeted drug delivery. The Docetaxel-loaded TPGS(2k) micelles with and without FA conjugation were found of desired size and size distribution, high drug encapsulation efficiency and favorable drug release. In vitro studies using MCF-7 cancer cells demonstrated significantly the higher cellular uptake of the formulated drug for TPGS(2k) micelle formulation than that for Taxotere®. The targeting effects for the FA conjugated TPGS(2k) micelles are also demonstrated. The IC₅₀ value, which is the drug concentration needed for 50% cell viability in the designated time period, is 103.4, 1.280 and 0.1480 μg/ml for MCF-7 cancer cells after 24, 48, and 72 h treatment respectively, which is greatly decreased to be 0.526, 0.251 and 0.233 μg/ml, i.e. a 99.5%, 80.4% decrease and 57.5% increase for the TPGS(2k) micelle formulation, and further decreased to be 0.1780, 0.1520 and 0.1140 μg/ml, i.e. a 99.8%, 88.1% and 23.0% decrease for the folic acid conjugated micelles, respectively. A synergistic effect between TPGS(2k) and Docetaxel is also achieved. The present work represents a new concept in the design of drug delivery systems--the carrier materials of the drug delivery system can also have therapeutic effects, which either modulate the side effects of, or promote a synergistic interaction with the formulated drug.