Temozolomide/PLGA microparticles plus vatalanib inhibits tumor growth and angiogenesis in an orthotopic glioma model

Nanotechnology-Based Strategies to Evaluate and Counteract Cancer Metastasis and Neoangiogenesis

Cancer metastasis is the major cause of cancer-related morbidity and mortality. It represents one of the greatest challenges in cancer therapy, both because of the ability of metastatic cells to spread into different organs, and because of the consequent heterogeneity that characterizes primary and metastatic tumors. Nanomaterials can potentially be used as targeting or detection agents owing to unique chemical and physical features that allow tailored and tunable theranostic functions. This review highlights nanomaterial-based approaches in the detection and treatment of cancer metastasis, with a special focus on the evaluation of nanostructure effects on cell migration, invasion, and angiogenesis in the tumor microenvironment.

Encapsulation of nor-β-lapachone into poly(d,l)-lactide-co-glycolide (PLGA) microcapsules: full characterization, computational details and cytotoxic activity against human cancer cell lines

In this work, we characterize nor-β-lapachone-loaded (NβL-loaded) microcapsules prepared using an emulsification/solvent extraction technique. Features such as surface morphology, particle size distribution, zeta potential, optical absorption, Raman and Fourier transform infrared spectra, thermal analysis data, drug encapsulation efficiency, drug release kinetics and in vitro cytotoxicity were studied. Spherical microcapsules with a size of 1.03 ± 0.46 μm were produced with an encapsulation efficiency of approximately 19%. Quantum DFT calculations were also performed to estimate typical interaction energies between a single nor-β-lapachone molecule and the surface of the microparticles. The NβL-loaded PLGA microcapsules exhibited a pronounced initial burst release. After the in vitro treatment with NβL-loaded microcapsules, a clear phagocytosis of the spheres was observed in a few minutes. The cytotoxic activity against a set of cancer cell lines was investigated.

Preparation of particulate polymeric therapeutics for medical applications

Particulate therapeutics fabricated from polymeric materials have become increasingly popular over the past several decades. Generally, polymeric systems are easy to synthesize and have tunable parameters, giving them significant potential for wide use in the clinic. They come in many different forms, including as nanoparticles, microparticles, and colloidal gels. In this review, we discuss the current preparation methods for each type of platform, as well as some representative applications. To achieve enhanced performance, lipid coatings and other surface modification techniques for introducing additional functionality are also mentioned. We hope that, by outlining the various methods and techniques for their preparation, it will be possible to provide insights into the utility of these polymeric platforms and further encourage their development for biomedical applications.

Controlled Release of Nor-β-lapachone by PLGA Microparticles: A Strategy for Improving Cytotoxicity against Prostate Cancer Cells

Prostate cancer is one of the most common malignant tumors in males and it has become a major worldwide public health problem. This study characterizes the encapsulation of Nor-β-lapachone (NβL) in poly(d,l-lactide-co-glycolide) (PLGA) microcapsules and evaluates the cytotoxicity of the resulting drug-loaded system against metastatic prostate cancer cells. The microcapsules presented appropriate morphological features and the presence of drug molecules in the microcapsules was confirmed by different methods. Spherical microcapsules with a size range of 1.03 ± 0.46 μm were produced with an encapsulation efficiency of approximately 19%. Classical molecular dynamics calculations provided an estimate of the typical adsorption energies of NβL on PLGA. Finally, the cytotoxic activity of NβL against PC3M human prostate cancer cells was demonstrated to be significantly enhanced when delivered by PLGA microcapsules in comparison with the free drug.

Drug encapsulated polymeric microspheres for intracranial tumor therapy: A review of the literature

Despite intensive surgical excision, radiation therapy, and chemotherapy, the current life expectancy for patients diagnosed with glioblastoma multiforme is only 12 to 15months. One of the approaches being explored to increase chemotherapeutic efficacy is to locally deliver chemotherapeutics encapsulated within degradable, polymeric microspheres. This review describes the techniques used to formulate drug encapsulated microspheres targeted for intracranial tumor therapy and how microsphere characteristics such as drug loading and encapsulation efficiency can be tuned based on formulation parameters. Further, the results of in vitro studies are discussed, detailing the varied drug release profiles obtained and validation of drug efficacy. Finally, in vivo results are summarized, highlighting the study design and the effectiveness of the drug encapsulated microspheres applied intracranially.

Effect of combined bevacizumab and temozolomide treatment on intramedullary spinal cord tumor

STUDY DESIGN

C6 glioma cells and an intramedullary spinal cord tumor model were used to evaluate the effect of bevacizumab (Avastin) or temozolomide (TMZ).

OBJECTIVE

In this study, we hypothesized that treatment with bevacizumab accelerates the therapeutic effect of TMZ on intramedullary gliomas in an animal model.

SUMMARY OF BACKGROUND DATA

Recently therapies for the management of intramedullary malignant gliomas include surgery, chemotherapy, and radiotherapy. Concurrent or adjuvant TMZ has been considered an emerging new treatment for intramedullary malignant gliomas; however, high-dose application of TMZ has limitation of side effect.

METHODS

C6 glioma cells were injected into the T5 level of the spinal cord, and TMZ and bevacizumab were administered 5 days after C6 inoculation (n = 7 for each group). Tumor size was analyzed using histology and magnetic resonance imaging at 13 days after tumor inoculation.

RESULTS

Histological analyses and magnetic resonance imaging findings showed that combined treatment with TMZ and bevacizumab reduced tumor mass. The tumor volume of control group was 2.8-fold higher than combined therapy (P < 0.05). Neurological outcomes demonstrated that combined therapy improved hind limb function more than TMZ-alone group or control group (P < 0.05).

CONCLUSION

This study shows that bevacizumab could be useful in combination with TMZ to increase the therapeutic benefits of TMZ for intramedullary spinal cord tumors.

LEVEL OF EVIDENCE

N/A.

Synergistic inhibition of angiogenesis and glioma cell-induced angiogenesis by the combination of temozolomide and enediyne antibiotic lidamycin

Present work mainly evaluated the inhibitory effects of lidamycin (LDM), an enediyne antibiotic, on angiogenesis or glioma-induced angiogenesis in vitro and in vivo, especially its synergistic anti-angiogenesis with temozolomide (TMZ). LDM alone efficiently inhibited proliferations and induced apoptosis of rat brain microvessel endothelial cells (rBMEC). LDM also interrupted the tube formation of rat brain microvessel endothelial cells (rBMEC) and rat aortic ring spreading. The blockade of rBMEC invasion and C6 cell-induced rBMEC migration by LDM was associated with decrease of VEGF secretion in a co-culture system. TMZ dramatically potentiated the effects of LDM on anti-proliferation, apoptosis induction, and synergistically inhibited angiogenesis events. As determined by western blot and ELISA, the interaction of tumor cells and the rBMEC was markedly interrupted by LDM plus TMZ with synergistic regulations of VEGF induced angiogenesis signal pathway, tumor cell invasion/migration, and apoptosis signal pathway. Immunofluorohistochemistry of CD31 and VEGF showed that LDM plus TMZ resulted in synergistic decrease of microvessel density (MVD) and VEGF expression in human glioma U87 cell subcutaneous xenograft. This study indicates that the high efficacy of LDM and the synergistic effects of LDM plus TMZ against glioma are mediated, at least in part, by the potentiated anti-angiogenesis.

Enhanced accumulation of curcumin and temozolomide loaded magnetic nanoparticles executes profound cytotoxic effect in glioblastoma spheroid model

Glioblastomas (GBMs) are highly lethal primary brain tumours. Treatment of these malignant gliomas remains ineffective as these are extremely resistant to chemotherapeutic applications. Furthermore, combination therapy for cancer treatment is becoming more popular because it generates synergistic anticancer effects, by reducing individual drug-related toxicity and associated side effects. Currently, magnetic nanoparticles (MNPs) based drug delivery system has attracted much more attention owing to its intrinsic magnetic properties and drug loading capacity. In the present study, MNPs based drug delivery approach for co-delivering of potent chemotherapeutic drugs such as Curcumin (herbal drug) and Temozolomide (DNA methylating agent) has been implemented. The dual drug loaded MNPs formulations were evaluated in two-dimensional (2-D) monolayer culture and three-dimensional (3-D) tumour spheroid culture of T-98G cells for understanding the therapeutic discrepancy. The dual drug loaded MNPs formulations demonstrated higher cytotoxic effect than single drug loaded MNPs formulations as compared to their corresponding native drugs in 2-D and 3-D culture. The combination index (CI) analysis revealed synergistic mode of action of dual drug loaded MNPs formulations, which was further confirmed by cell death induction assay mediated by acridine orange (AO)/propidium iodide (PI) staining, illustrating higher efficacy of the formulation towards GBM therapy.

Drug delivery strategies for the treatment of malignant gliomas

As primary brain tumors, malignant gliomas are known to be one of the most insidious types of brain cancer afflicting the humans. The current standard strategy for the treatment of malignant gliomas includes the surgical resection of the tumor when possible, followed by a combination of radiotherapy and/or a certain chemotherapeutic protocol. However, due to the short mean survival, frequent recurrences, and poor prognosis associated with the tumors, new therapeutic strategies are investigated consecutively. These novel drug delivery approaches can be subdivided as systemic and local drug administration. This review focuses on localized drug delivery strategies for the treatment of malignant gliomas, including the injections, infusions, trans-nasal delivery systems, convection enhanced delivery (CED) systems, and various types of polymeric implants. Furthermore, systemic strategies to increase the drug penetration into the brain, such as temporary disruption of the blood brain barrier (BBB), chemical modification of the available therapeutic substances, and utilization of endogenous transport systems will be briefly discussed.

Temozolomide loaded PLGA-based superparamagnetic nanoparticles for magnetic resonance imaging and treatment of malignant glioma

Polysorbate 80 coated temozolomide-loaded PLGA-based superparamagnetic nanoparticles (P80-TMZ/SPIO-NPs) were successfully synthesized and characterized as drug carriers and diagnosis agent for malignant brain glioma. The mean size of P80-TMZ/SPIO-NPs was 220 nm with narrow hydrodynamic particle size distribution. The superparamagnetic characteristic of P80-TMZ/SPIO-NPs was proved by vibration simple magnetometer. P80-TMZ/SPIO-NPs exhibited high drug loading and encapsulation efficiency as well as good sustained drug release performance for 15 days. MTT assay demonstrated the antiproliferative effect of P80-TMZ/SPIO-NPs for C6 glioma cells. Significant cellular uptake of P80-TMZ/SPIO-NPs was evaluated in C6 glioma cells by fluorescence microscopy, Prussian blue staining, and atomic absorption spectrophotometer (AAS) for qualitative and quantitative study, respectively. MRI scanning analyses in vitro indicated that P80-TMZ/SPIO-NPs could be used as a good MRI contrast agent. Polysorbate 80 coated temozolomide-loaded PLGA-based superparamagnetic nanoparticles could be able to promise a multifunctional theragnostic carrier of brain cancer.

The effect of temozolomide/poly(lactide-co-glycolide) (PLGA)/nano-hydroxyapatite microspheres on glioma U87 cells behavior

In this study, we investigated the effects of temozolomide (TMZ)/Poly (lactide-co-glycolide)(PLGA)/nano-hydroxyapatite microspheres on the behavior of U87 glioma cells. The microspheres were fabricated by the “Solid/Water/Oil” method, and they were characterized by using X-Ray diffraction, scanning electron microscopy and differential scanning calorimetry. The proliferation, apoptosis and invasion of glioma cells were evaluated by MTT, flow cytometry assay and Transwell assay. The presence of the key invasive gene, α_Vβ3 integrin, was detected by the RT-PCR and Western blot method. It was found that the temozolomide/PLGA/nano-hydroxyapatite microspheres have a significantly diminished initial burst of drug release, compared to the TMZ laden PLGA microspheres. Our results suggest they can significantly inhibit the proliferation and invasion of glioma cells, and induce their apoptosis. Additionally, α_Vβ3 integrin was also reduced by the microspheres. These data suggest that by inhibiting the biological behavior of glioma cells in vitro, the newly designed temozolomide/PLGA/nano-hydroxyapatite microspheres, as controlled drug release carriers, have promising potential in treating glioma.