Current Pharmaceutical Biotechnology - Volume 14, Issue 13, 2013

Artificial skeletal muscle tissues composed of cells are expected to be used for applications of regenerative medicine and drug screening. Generally, however, the physical forces generated by tissue-engineered skeletal muscle are lower than those of skeletal muscle tissues found in the body. Local hyperthermia is used for many diseases including muscle injuries. It was recently reported that mild heat treatment improved skeletal muscle functions. In this study, we investigated the effects of mild heat treatment on the tissue-engineered skeletal muscle tissues in vitro. We used magnetite cationic liposomes to label C2C12 myoblast cells magnetically, and constructed densely packed artificial skeletal muscle tissues by using magnetic force. Cell culture at 39°C promoted the differentiation of myoblast cells into myotubes. Moreover, the mild and transient heat treatment improved the contractile properties of artificial skeletal muscle tissue constructs. These findings indicate that the culture method using heat treatment is a useful approach to enhance functions of artificial skeletal muscle tissue.

A 46-year-old female underwent surgery for cancer of the right breast mammary (T3N2M0) in Sep 2010. Following post surgery, adjuvant chemotherapy of CAF regimens (cyclophosphamide+adriamycin+fluorouracil) was administered. Two years later, multiple pulmonary and skeletal metastatic lesions had been found by CT (computerized tomography) and ECT (emission computed tomograph) imaging. She received the treatment of second-line chemotherapy regimens of GP (cisplatin + gemcitabine). In the meantime, we administered Chinese traditional herb drugs (Fei Decoction, mixed a variety of effective herbal components) to help her recover from the poor condition. After taking the Chinese herbs for 2 months, the tumour marker (CEA, CA15-3) dramatically decreased, resulting in the normal range. Both lung and bone metastatic sites reduced according to CT and ECT imaging, and the patient felt free from the complaint of pulmonary and cardiac discomfort. Over time, the quality of life has been greatly improved, we have managed to prolong the PFS (progression-free-survival) and TTP (time-to-progression) from the onset to date. CTM (Chinese traditional medicine) considers human body as a dynamic platform in which all organs are correlative and bind each other. Relationship between heart, liver, spleen, lung and kidney is like an interlink between mother and son, and runs in cycle as a circle. In the course of this combined treatment, we showed that Chinese herbal medicine played an important role in the therapy of breast cancer. Chinese herbs might be an additional choice with their better benefits and tolerability in the treatment of recurrent breast cancer.

Treatments of obesity and type II diabetes target often gene functions involved in appetite-satiety, fat and carbohydrate metabolism or thermogenesis. None of these, have provided efficient drug therapy due to a large number of genes involved in weight and energy management, the redundancy of biochemical pathways and the environmental factors. Here I discuss a new approach based on studies of genes/proteins that are associated with human “lean or starvation" phenotype that became very rare in the course of evolution. This approach has led to the identification of the congenital enteropeptidase deficiency gene and the Andersons Disease gene as a potential targets for obesity and type II diabetes treatment. The advantages of these targets are: 1) they are expressed exclusively in the intestine; 2) they are peripheral targets as opposed to systemic targets; 3) they are not redundant targets. These targets open new hopes for the development of novel drugs for the treatment of common metabolic syndrome.

Malignant glioma is a primary tumor of the central nervous system, representing a major cause of mortality in a young, productive subset of population. The management of this neoplasm requires aggressive treatments, including radiotherapy. Accurate imaging plays a central role in treatment planning process with curative intent based on radiation therapy. In order to maximize the radiation dose to the tumor and to minimize the damage to the normal surrounding tissue, a reliable identification of viable tumor margins is indeed required. The use of PET in the treatment planning process has become more promising over the years, although many important questions must be addressed. The aim of this article is to critically review the evidence supporting PET in radiotherapy planning, with special emphasis on the role of novel radiopharmaceuticals, comparing its sensitivity and specificity with respect to 18F-FDG and other anatomic imaging modalities.

Objective: A multifunctional tumor-targeting drug delivery system employing single-walled carbon nanotubes (SWCNT) as drug carriers, AS1411 as targeting ligand and doxorubicine (DOX) as a model chemotherapy drug was constructed. Methods: Firstly, SWCNT were modified with F68 (4.0 mg/ml) by ultrasonic dispersing technology due to the action of hydrophobic force and Van der Waals force, endowing SWCNT water dispersions and biocompatibility. Meanwhile, DOX could be easily absorbed on the surface of SWCNT by the π-π stacking, electrostatic adsorption and hydrophobic interactions. Finally, AS1411 was attached to the surface of DOX-SWCNT by the π-π stacking and electrostatic adsorption to obtain a tumor-targeting delivery system. Cellular uptake, anti-tumor effect in vitro and in vivo, cell cycle and apoptosis and biodistribution of AS1411-DOX-SWCNT were investigated, compared with the DOX solution. Conclusion: This AS1411-mediated DOX-loaded SWCNT (AS1411-DOX-SWCNT) delivery system not only retained both optical properties of SWCNT and cytotoxicity of DOX but also could accumulate in tumors, which facilitated combination of chemotherapy and photothermal therapy. AS1411-DOX-SWCNT could effectively promote DOX cellular uptake and then increase intracellular accumulation as a targeting delivery system. AS1411-DOX-SWCNT by NIR laser excited could trigger S phase arrest and the late stage apoptotic on PC3 cancer cells. The investigation in vivo further confirmed that this system possessed higher tumor targeting capacity and antitumor efficacy than DOX, especially with NIR laser irradiation.

Targeted nanoparticulated drug delivery systems have gained much attention owing to their potential in elevating anti-tumor effect and decreasing drug-originated side effects. In this contribution, a kind of dual glioma targeting delivery system was developed through co-modification nanoparticles with interlukin-13 peptide (IL-13p) and RGD peptide (IRNPs), in which IL-13p could target to IL13Rα2 on tumor cells and RGD could target to αvβ3 on neovasculature. The model drug, docetaxel (DTX), could release from the unmodified nanoparticles (NPs) and IRNPs at a sustained manner. In vitro, the uptake of IRNPs by C6 (a glioma cell line) cells was time- and concentration-dependent, which was significantly higher than the uptake of NPs and single modified nanoparticles. After loading with DTX, IRNPs induced the highest percentage of apoptotic cells. In vivo, DTX-loaded IRNPs induced obviously higher apoptosis of cells in glioma site. These results indicated the dual modification could improve the cellular uptake as well as antitumor effect, which demonstrated IRNPs were promising drug delivery systems for glioma targeting treatment.

Fluorescent nanodiamonds (FNDs) are one of the new and very promising biocompatible nanomaterials that can be used both as a fluorescence imaging agent and a highly versatile platform for controlled functionalization to target and deliver a wide spectrum of therapeutic agents. Among the remarkable fluorescence properties are excellent photostability, emission between 600-700nm, quantum yield of 1 and moderately long fluorescence lifetimes. However the low absorption cross section of fluorescent (N-V)- centers limits FNDs’ brightness. In this work we show that an approach based on the Forster resonance energy transfer (FRET) may significantly enhance the fluorescence signal observed from a single ND. We demonstrate that organic dyes (fluorophores) attached to the FND surface can efficiently transfer the excitation energy to (N-V)- centers. Multiple dyes positioned in close proximity to the ND facile surface may serve as harvesting antennas transferring excitation energy to the fluorescent centers. We propose that, with the help of some of the functional groups present on the FND surface, we can either directly link flurophores or use scalable dendrimer chemistry to position many organic dyes at a calibrated distance. Also, the remaining multiple functional groups will be still available for particle targeting and drug delivery. This opens a new way for designing a new type of theranostics particles of ultrahigh brightness, high photostability, specific targeting, and high capacity for drug delivery.

In our previous paper we showed that the MMP-9 enzyme recognizes a specific peptide sequence, Lys-Gly- Pro-Arg-Ser-Leu-Ser-Gly-Lys, and cleaves the peptide into two parts [1]. In this study, the peptide is labeled with two dyes, carboxyfluorescein (5-FAM) and Cy5. A highly efficient energy transfer of over 80% results in a dominant emission of Cy5 at ~670 nm with an excitation of 470 nm. Severance of the peptide by the MMP-9 enzyme eliminates Förster Resonance Energy Transfer (FRET) and strongly increases the fluorescence of the 5-FAM dye. In this manuscript we describe the strategy for a FRET-based method for MMP-9 enzyme detection. The basic aim is to apply a ratio-metric sensing technique in which a ratio of green/red fluorescence intensity is measured as a function of enzyme concentration. The ratio-metric method eliminates many experimental variables and enables accurate MMP-9 detection.

Although BSA Au clusters fluoresce in red region (λmax: 650nm), they are of limited use due to low fluorescence quantum yield (~6%). Here we report an enhanced fluorescence imaging application of fluorescent bio-nano probe BSA Au clusters using multipulse excitation scheme. Multipulse excitation takes advantage of long fluorescence lifetime (> 1μs) of BSA Au clusters and enhances its fluorescence intensity 15 times over short lived cellular auto-fluorescence. Moreover we have also shown that by using time gated detection strategy signal (fluorescence of BSA Au clusters) to noise (auto-fluorescence) ratio can be increased by 30 fold. Thereby with multipulse excitation long lifetime probes can be used to develop biochemical assays and perform optical imaging with zero background.

Background: Prostate cancer is one of the leading malignant tumors in men. Current therapies are associated with severe side effects making it problematic for many multi-morbid patients to receive treatment. Prostate specific antigen, serum response factor (SRF), signal transducer and activator of transcription-3 (STAT3), hypoxia-inducible factor-1α (HIF-1α), HIF-2α, E2F1 and Survivin are well known proteins being overexpressed in cancer cells, expediting cell growth and also demonstrated in prostate cancer cells. Targeting these genes using the RNA-Interference pathway could be a new approach for prostate cancer therapy with fewer side effects. Methods: Three prostate cancer cell lines were cultured under standard conditions and transfected with three different concentrations (25 nM, 50 nM, 100 nM) of specific small interfering RNAs (siRNAs) targeting SRF, STAT3, HIF1α, HIF2α, E2F1 and Survivin in a non-viral manner. Cells treated with non-specific siRNA (SCR-siRNA) served as control. Changes of messenger RNA (mRNA) levels were determined using quantitative real-time polymerase chain reaction (qRT-PCR). The analysis of the effect of siRNA on the number of cells was detected using CASY cell counter system. Results: Transfections of the PC-3 cell line with specific siRNA especially against Survivin, E2F1, HIF1α- and HIF2α-siRNA resulted in a significant reduction of intracellular mRNA concentration together with a significant decreased number of cells. In the LnCAP and DU-145 cell lines Survivin and E2F1 showed similar effects. The impact of silencing STAT3 or SRF showed little influence on the amount of cells in all three cell lines. Conclusions: This study shows that RNAi succeeds in silencing gene expression and reducing the number of cells in differing dimensions depending on the transfected cell line and used siRNA.