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Mathupala SP, Guthikonda M, Sloan AE. RNAi Based Approaches to the Treatment of Malignant Glioma. Technol Cancer Res Treat 2016; 5:261-9. [PMID: 16700622 DOI: 10.1177/153303460600500313] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
RNA interference (RNAi) is a recently discovered, powerful molecular mechanism that can be harnessed to engineer gene-specific silencing in mammalian tissues. A mechanism, where short double-stranded RNA (dsRNA) molecules, when introduced into cells elicit specific “knock-down” of gene expression via degradation of targeted messenger RNA, has lately become the technique of choice for analysis of gene function in oncology research. Thus, RNAi is currently being extensively evaluated as a potential therapeutic strategy against malignant gliomas, since surgical, radiological, and chemotherapeutic interventions during the past few decades have done little to improve the poor prognosis rate for patients with these dreaded tumors. This review summarizes the pre-clinical studies that are currently underway to test the validity of RNAi as a potential therapeutic strategy against malignant gliomas, and discusses the potential technical Hurdles that remain to be overcome before the technique can become a promising clinical therapy to combat this frequently lethal disease.
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Affiliation(s)
- Saroj P Mathupala
- Department of Neurological Surgery, Karmanos Cancer Institute, Wayne State University School of Medicine, 808 HWCRC, 4100 John R. Road, Detroit, MI 48201, USA.
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Morshed RA, Cheng Y, Auffinger B, Wegscheid ML, Lesniak MS. The potential of polymeric micelles in the context of glioblastoma therapy. Front Pharmacol 2013; 4:157. [PMID: 24416018 PMCID: PMC3874582 DOI: 10.3389/fphar.2013.00157] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 11/29/2013] [Indexed: 12/12/2022] Open
Abstract
Glioblastoma multiforme (GBM), a type of malignant glioma, is the most common form of brain cancer found in adults. The current standard of care for GBM involves adjuvant temozolomide-based chemotherapy in conjunction with radiotherapy, yet patients still suffer from poor outcomes with a median survival of 14.6 months. Many novel therapeutic agents that are toxic to GBM cells in vitro cannot sufficiently accumulate at the site of an intracranial tumor after systemic administration. Thus, new delivery strategies must be developed to allow for adequate intratumoral accumulation of such therapeutic agents. Polymeric micelles offer the potential to improve delivery to brain tumors as they have demonstrated the capacity to be effective carriers of chemotherapy drugs, genes, and proteins in various preclinical GBM studies. In addition to this, targeting moieties and trigger-dependent release mechanisms incorporated into the design of these particles can promote more specific delivery of a therapeutic agent to a tumor site. However, despite these advantages, there are currently no micelle formulations targeting brain cancer in clinical trials. Here, we highlight key aspects of the design of polymeric micelles as therapeutic delivery systems with a review of their clinical applications in several non-brain tumor cancer types. We also discuss their potential to serve as nanocarriers targeting GBM, the major barriers preventing their clinical implementation in this disease context, as well as current approaches to overcome these limitations.
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Affiliation(s)
- Ramin A Morshed
- The Brain Tumor Center, The University of Chicago Pritzker School of Medicine Chicago, IL, USA
| | - Yu Cheng
- The Brain Tumor Center, The University of Chicago Pritzker School of Medicine Chicago, IL, USA
| | - Brenda Auffinger
- The Brain Tumor Center, The University of Chicago Pritzker School of Medicine Chicago, IL, USA
| | - Michelle L Wegscheid
- The Brain Tumor Center, The University of Chicago Pritzker School of Medicine Chicago, IL, USA
| | - Maciej S Lesniak
- The Brain Tumor Center, The University of Chicago Pritzker School of Medicine Chicago, IL, USA
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Ahmed AU, Tyler MA, Thaci B, Alexiades NG, Han Y, Ulasov IV, Lesniak MS. A comparative study of neural and mesenchymal stem cell-based carriers for oncolytic adenovirus in a model of malignant glioma. Mol Pharm 2011; 8:1559-72. [PMID: 21718006 DOI: 10.1021/mp200161f] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Glioblastoma multiforme is a primary malignancy of the central nervous system that is universally fatal due to its disseminated nature. Recent investigations have focused on the unique tumor-tropic properties of stem cells as a novel platform for targeted delivery of anticancer agents to the brain. Neural stem cells (NSCs) and mesenchymal stem cells (MSCs) both have the potential to function as cell carriers for targeted delivery of a glioma restricted oncolytic virus to disseminated tumor due to their reported tumor tropism. In this study, we evaluated NSCs and MSCs as cellular delivery vehicles for an oncolytic adenovirus in the context of human glioma. We report the first preclinical comparison of the two cell lines and show that, while both stem cell lines are able to support therapeutic adenoviral replication intracellularly, the amount of virus released from NSCs was a log higher than the MSC (p < 0.001). Moreover, only virus loaded NSCs that were administered intracranially in an orthotopic glioma model significantly prolonged the survival of tumor bearing animals (median survival for NSCs 68.5 days vs 44 days for MSCs, p < 0.002). Loading oncolytic adenovirus into NSCs and MSCs also led to expression of both pro- and anti-inflammatory genes and decreased vector-mediated neuroinflammation. Our results indicate that, despite possessing a comparable migratory capacity, NSCs display superior therapeutic efficacy in the context of intracranial tumors. Taken together, these findings argue in favor of NSCs as an effective cell carrier for antiglioma oncolytic virotherapy.
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Affiliation(s)
- Atique U Ahmed
- The Brain Tumor Center, The University of Chicago, Chicago, Illinois 60637, USA
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Li J, Fatima A, Komarova S, Ugai H, Uprety P, Roth JC, Wang M, Oster RA, Curiel DT, Matthews QL. Evaluation of adenovirus capsid labeling versus transgene expression. Virol J 2010; 7:21. [PMID: 20102632 PMCID: PMC2824641 DOI: 10.1186/1743-422x-7-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 01/26/2010] [Indexed: 02/04/2023] Open
Abstract
Adenoviral vectors have been utilized for a variety of gene therapy applications. Our group has incorporated bioluminescent, fluorographic reporters, and/or suicide genes within the adenovirus genome for analytical and/or therapeutic purposes. These molecules have also been incorporated as capsid components. Recognizing that incorporations at either locale yield potential advantages and disadvantages, our report evaluates the benefits of transgene incorporation versus capsid incorporation. To this end, we have genetically incorporated firefly luciferase within the early region 3 or at minor capsid protein IX and compared vector functionality by means of reporter readout.
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Affiliation(s)
- Jing Li
- Division of Human Gene Therapy, Department of Medicine, Gene Therapy Center, University of Alabama at Birmingham, AL 35294, USA
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Abstract
BACKGROUND Two fundamental difficulties in the delivery of drugs to treat central nervous system (CNS) diseases are the systemic delivery of therapeutics across the bloodbrain-barrier (BBB), and the targeting of drugs to specific tissues or cells within the brain. With the advent and promise of RNA-based therapeutics that utilize RNA interference (RNAi) to trigger specific silencing of genes within diseased tissues, the necessity to surmount such obstacles has become even more urgent. OBJECTIVE Most pre-clinical and clinical studies on delivery of RNAi to the CNS have utilized invasive, intra-cerebral delivery of RNA to the targeted tissue. Thus, methods need to be developed to facilitate delivery of therapeutically significant quantities of RNA to the CNS via the systemic route, and to elicit clinically significant RNAi effects within the CNS tissues. METHODS Cell-penetrating-peptides (CPPs) are 'molecular delivery vehicles' that can traverse cell membranes and co-transport peptides or polynucleotides. The present invention examines 1) the utility of CPP-RNA duplexes for delivery of RNA to CNS tissues and, 2) cell-mediated release of the RNA payload once the CPP-RNA duplex is internalized by the CNS cells. CONCLUSIONS The invention and embodiments listed therein outline molecular tools that can be adapted for non-invasive, systemic delivery of therapeutic RNA to the CNS in a future clinical setting.
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Affiliation(s)
- Saroj P Mathupala
- Department of Neurological Surgery, Wayne State University School of Medicine, Karmanos Cancer Institute, Detroit, MI 48201, USA.
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Slager J, Tyler B, Shikanov A, Domb AJ, Shogen K, Sidransky D, Brem H. Local controlled delivery of anti-neoplastic RNAse to the brain. Pharm Res 2009; 26:1838-46. [PMID: 19415468 DOI: 10.1007/s11095-009-9893-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2009] [Accepted: 04/11/2009] [Indexed: 11/25/2022]
Abstract
PURPOSE Antineoplastic RNAse proteins, also known as Amphibinases, have been shown effective against various solid tumors but were found selectively neurotoxic to Purkinje cells in the cerebellum. This work describes the use of a waxy biodegradable poly(ricinoleic-co-sebacic acid) for the local controlled delivery of cytotoxic amphibinases in the parietal lobe of the brain in an attempt to overcome cerebellar neuronal toxicity while affecting glioma cells. METHODS Amphibinase analogues were encapsulated in poly(ricinoleic-co-sebacic acid) formulations using mix-melt technology and loaded onto surgical foam. In-vitro release was monitored by BCA colorimetry and by RNAse specific bioactivity. The implants were inserted into rat brains bearing 9L glioma to assess toxicity and efficacy. RESULTS The various formulations showed extended linear release for several weeks with minimal burst effect. Best in-vivo efficacy was obtained with ACC7201 containing implants, resulting in the extension of the median survival from 13 to 18 days with 13% long-term survivors. CONCLUSION Antineoplastic proteins were released from a p(SA-RA) polyanhydride implants in a controlled manner, providing efficacy against 9L glioma, while evading neurotoxicity in the cerebellum. The controlled release of Amphibinases forms the potential for a new therapy against brain tumors.
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Affiliation(s)
- Joram Slager
- Department of Neurosurgery, Johns Hopkins University, CRB2-2M41, 1550 Orleans Street, Baltimore, Maryland 21231, USA.
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Patel MM, Goyal BR, Bhadada SV, Bhatt JS, Amin AF. Getting into the brain: approaches to enhance brain drug delivery. CNS Drugs 2009; 23:35-58. [PMID: 19062774 DOI: 10.2165/0023210-200923010-00003] [Citation(s) in RCA: 271] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Being the most delicate organ of the body, the brain is protected against potentially toxic substances by the blood-brain barrier (BBB), which restricts the entry of most pharmaceuticals into the brain. The developmental process for new drugs for the treatment of CNS disorders has not kept pace with progress in molecular neurosciences because most of the new drugs discovered are unable to cross the BBB. The clinical failure of CNS drug delivery may be attributed largely to a lack of appropriate drug delivery systems. Localized and controlled delivery of drugs at their desired site of action is preferred because it reduces toxicity and increases treatment efficiency. The present review provides an insight into some of the recent advances made in the field of brain drug delivery.The various strategies that have been explored to increase drug delivery into the brain include (i) chemical delivery systems, such as lipid-mediated transport, the prodrug approach and the lock-in system; (ii) biological delivery systems, in which pharmaceuticals are re-engineered to cross the BBB via specific endogenous transporters localized within the brain capillary endothelium; (iii) disruption of the BBB, for example by modification of tight junctions, which causes a controlled and transient increase in the permeability of brain capillaries; (iv) the use of molecular Trojan horses, such as peptidomimetic monoclonal antibodies to transport large molecules (e.g. antibodies, recombinant proteins, nonviral gene medicines or RNA interference drugs) across the BBB; and (v) particulate drug carrier systems. Receptor-mediated transport systems exist for certain endogenous peptides, such as insulin and transferrin, enabling these molecules to cross the BBB in vivo.The use of polymers for local drug delivery has greatly expanded the spectrum of drugs available for the treatment of brain diseases, such as malignant tumours and Alzheimer's disease. In addition, various drug delivery systems (e.g. liposomes, microspheres, nanoparticles, nanogels and bionanocapsules) have been used to enhance drug delivery to the brain. Recently, microchips and biodegradable polymers have become important in brain tumour therapy.The intense search for alternative routes of drug delivery (e.g. intranasal drug delivery, convection-enhanced diffusion and intrathecal/intraventricular drug delivery systems) has been driven by the need to overcome the physiological barriers of the brain and to achieve high drug concentrations within the brain. For more than 30 years, considerable efforts have been made to enhance the delivery of therapeutic molecules across the vascular barriers of the CNS. The current challenge is to develop drug delivery strategies that will allow the passage of drug molecules through the BBB in a safe and effective manner.
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Affiliation(s)
- Mayur M Patel
- Institute of Pharmacy, Nirma University of Science and Technology, Ahmedabad, India
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Combination of adenoviral virotherapy and temozolomide chemotherapy eradicates malignant glioma through autophagic and apoptotic cell death in vivo. Br J Cancer 2009; 100:1154-64. [PMID: 19277041 PMCID: PMC2664399 DOI: 10.1038/sj.bjc.6604969] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Conditionally replicative adenoviruses (CRAds) represent a novel treatment strategy for malignant glioma. Recent studies suggest that the cytopathic effect elicited by these vectors is mediated through autophagy, a form of programmed cell death. Likewise, temozolomide (TMZ), a chemotherapeutic agent used for the treatment of malignant gliomas, also triggers autophagic cell death. In this study, we examined the potential to combine the two treatments in the setting of experimental glioma. In vitro, pretreatment with TMZ followed by CRAd-Surivin-pk7 enhanced cytotoxicity against a panel of glioma cell lines. Western blot analysis showed increased expression of BAX and p53, decreased expression of BCL2 and elevated level of APG5. Treatment with TMZ followed by CRAd-Survivin-pk7 (CRAd-S-pk7) led to a significant over-expression of autophagy markers, acidic vesicular organelles and light-chain 3 (LC3). These results were further evaluated in vivo, in which 90% of the mice with intracranial tumours were long-term survivors (>100 days) after treatment with TMZ and CRAd-S-pk7 (P<0.01). Analysis of tumours ex vivo showed expression of both LC3 and cleaved Caspase-3, proving that both autophagy and apoptosis are responsible for cell death in vivo. These results suggest that combination of chemovirotherapy offers a powerful tool against malignant glioma and should be further explored in the clinical setting.
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Forbes Z, Yellen B, Halverson D, Fridman G, Barbee K, Friedman G. Validation of High Gradient Magnetic Field Based Drug Delivery to Magnetizable Implants Under Flow. IEEE Trans Biomed Eng 2008; 55:643-9. [DOI: 10.1109/tbme.2007.899347] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Ulasov IV, Zhu ZB, Tyler MA, Han Y, Rivera AA, Khramtsov A, Curiel DT, Lesniak MS. Survivin-driven and fiber-modified oncolytic adenovirus exhibits potent antitumor activity in established intracranial glioma. Hum Gene Ther 2007; 18:589-602. [PMID: 17630837 DOI: 10.1089/hum.2007.002] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The poor prognosis of patients with malignant gliomas necessitates the development of novel therapies. Virotherapy, using genetically engineered adenovectors that selectively replicate in and kill neoplastic cells, represents one such strategy. In this study, we examined several oncolytic vectors with modified transcriptional and transductional control of viral replication. First, we incorporated the survivin promoter (S) to drive E1A gene expression. We then modified the adenovirus serotype 5 (Ad5) fiber protein via genetic knob switching or incorporation of peptide ligands to target the following glioma-associated receptors: the Ad3 attachment protein, or CD46, alpha(v) beta(3)/alpha(v)beta(5) integrins, or heparan sulfate proteoglycans. The three conditionally replicative adenoviruses, CRAd-S-5/3, CRAd-S-RGD, and CRAd-S-pk7, were then examined in vitro with respect to transduction efficiency and tissue specificity. The most promising virus was then tested in vivo for evidence of tumor growth inhibition. CRAd-S-pk7 provided the highest level of viral replication and tumor oncolysis in glioma cell lines. At the same time, we observed minimal viral replication and toxicity in normal human brain. Injection of CRAd-S-pk7 inhibited xenograft tumor growth by more than 300% (p < 0.001). Sixty-seven percent of treated mice with intracranial tumors were long-term survivors (>110 days; p < 0.005). Analysis of tumor tissue indicated increased adenoviral infectivity, decreased mitotic activity, and enhanced tumor apoptosis. These findings demonstrate the effectiveness of CRAd-S-pk7 and provide the rationale for further development of this novel oncolytic virus for glioma gene therapy.
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Affiliation(s)
- Ilya V Ulasov
- Division of Neurosurgery, Department of Surgery, University of Chicago, Chicago, IL 60637, USA
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Benny O, Kim SK, Gvili K, Radzishevsky IS, Mor A, Verduzco L, Menon LG, Black PM, Machluf M, Carroll RS. In vivo
fate and therapeutic efficacy of PF‐4/CTF microspheres in an orthotopic human glioblastoma model. FASEB J 2007; 22:488-99. [PMID: 17873103 DOI: 10.1096/fj.07-8801com] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The correlation between glioma grade and angiogenesis suggests that antiangiogenic therapies are potentially therapeutically effective for these tumors. However, to achieve tumor suppression, antiangiogenic therapies need to be administered daily using high systemic quantities. We designed a biodegradable polymeric device that overcomes those barriers by providing sustained local delivery of a C-terminal fragment of platelet factor 4 (PF-4/CTF), an antiangiogenic agent. Fluorescent-labeled microspheres composed of poly lactic-coglycolic acid (PLGA) were loaded with rhodamine-labeled PF-4/CTF and formulated to release their contents over time. Fluorescent labeling enabled the correlation between the in vitro to the in vivo kinetic and release studies. PF-4/CTF microspheres were injected into established intracranial human glioma tumors in nude mice. Noninvasive magnetic resonance imaging (MRI) was used to assess the therapeutic response. Tumor size, microvessel density, proliferation, and apoptosis rate were measured by histological analysis. Intracranially, the microspheres were located throughout the tumor bed and continuously released PF-4/CTF during the entire experimental period. MRI and histological studies showed that a single injection of microspheres containing PF-4/CTF caused a 65.2% and 72% reduction in tumor volume, respectively, with a significant decrease in angiogenesis and an increase in apoptosis. Our data demonstrate that polymeric microspheres are an effective therapeutic approach for delivering antiangiogenic agents that result in the inhibition of glioma tumor growth.
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Affiliation(s)
- Ofra Benny
- M.M., Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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Mathupala SP, Mittal S, Guthikonda M, Sloan AE. MicroRNA and brain tumors: a cause and a cure? DNA Cell Biol 2007; 26:301-10. [PMID: 17504026 PMCID: PMC3385864 DOI: 10.1089/dna.2006.0560] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Malignant brain tumors, including high-grade gliomas, are among the most lethal of all cancers. Despite considerable advances, including multi-modal treatments with surgery, radiotherapy, and chemotherapy, the overall prognosis remains dismal for patients diagnosed with these tumors. With the discovery of RNA interference (RNAi) for target-specific gene silencing via small interfering RNA (siRNA), a novel method to target malignant gliomas has been exposed, an endeavor that is aggressively being carried out in numerous laboratories. However, practical difficulties in tissue- or organ-specific targeting of therapeutic quantities of siRNA still preclude its applicability in a clinical setting. MicroRNA (miRNA), an endogenously expressed form of siRNA, not only presents an alternate method to induce RNAi in a given diseased tissue or organ, but also exposes a unique set of diagnostic markers that can be used to identify, and then differentiate between tumor grades. Thus, miRNA can be considered the cells' answer to siRNA. Discovered over a decade ago, miRNA is fast becoming recognized as crucial in regulating gene expression in cancers. Therein lies the therapeutic potential of miRNA, as it may now be possible to induce or inhibit RNAi in a given diseased cell population by controlling the cells' miRNA expression profile. This review outlines the potential of miRNA as a therapeutic strategy against high-grade gliomas, and also the technological hurdles that need to be addressed before this promising technique can be administered in a clinical setting.
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Affiliation(s)
- Saroj P Mathupala
- Department of Neurological Surgery, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Yemisci M, Bozdag S, Cetin M, Söylemezoglu F, Capan Y, Dalkara T, Vural I. Treatment of malignant gliomas with mitoxantrone-loaded poly (lactide-co-glycolide) microspheres. Neurosurgery 2007; 59:1296-302; discussion 1302-3. [PMID: 17277693 DOI: 10.1227/01.neu.0000245607.99946.8f] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVE Mitoxantrone (MTZ) has potent in vitro activity against malignant glioma cell lines, but it cannot be used effectively as a systemic agent for the treatment of brain tumors because of its poor central nervous system penetration. However, MTZ-loaded poly(lactide-co-glycolide) (PLGA) microspheres may be injected into the peritumoral area and into tumor tissue to provide effective and sustained local drug concentrations without causing systemic side effects. METHODS Fisher rats were randomized into three groups. The first group (n = 9) was concomitantly implanted with rat glioma (RG2) cells and blank PLGA microspheres. The second group (n = 6) was implanted with RG2 cells and MTZ-loaded PLGA microspheres. The third group (n = 9) was implanted with RG2 cells, and MTZ-loaded PLGA microspheres were injected into the same area after 7 days. Animals were sacrificed on Day 15 or 35. Tumor volumes were measured after hematoxylin and eosin staining. Distribution kinetics of MTZ in the brain was determined by high-performance liquid chromatography in nine rats injected with MTZ-loaded microspheres. RESULTS The tumor volumes were 76 +/- 11 and 107 +/- 11 mm (mean +/- standard error) on Days 15 (n = 6) and 35 (n = 3), respectively, in the control group. In rats treated with MTZ-loaded microspheres on Day 7, tumor volumes were significantly reduced to 17 +/- 4 and 23 +/- 2 mm on Days 15 (n = 6) and 35 (n = 3), respectively. No tumor formation was observed when glioma cells and MTZ-loaded PLGA microspheres were implanted concomitantly (n = 6). No systemic side effects or parenchymal inflammatory infiltration were observed in either group of rats. Brain MTZ concentration was highest at the injection site and declined with time and distance from the injection site and with time. CONCLUSION These data demonstrate that MTZ-loaded PLGA microspheres can deliver therapeutic concentrations of drug to the tumor and prevent glioma growth without causing side effects. This treatment method may increase the efficiency of antineoplastic therapy and positively impact survival.
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Affiliation(s)
- Muge Yemisci
- Department of Neurology, Institute of Neurological Sciences and Psychiatry, Hacettepe University, Ankara, Turkey
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