Administration-dependent efficacy of ferrociphenol lipid nanocapsules for the treatment of intracranial 9L rat gliosarcoma

Diversely substituted poly(N-vinyl amide) derivatives towards non-toxic, stealth and pH-responsive lipid nanocapsules

Surface modification of lipid nanocapsules (LNC) is necessary to impart stealth properties to these drug carriers and enhance their accumulation into the tumor microenvironment. While pegylation is commonly used to prolong the circulation time of LNC, the increased presence of anti-PEG antibodies in the human population and the internalization issues associated to the PEG shell are strong incentives to search alternatives. This work describes the development of amphiphilic poly(N-vinyl amide)-based (co)polymers, including pH-responsive ones, and their use as LNC modifiers towards improved drug delivery systems. RAFT polymerization gave access to a series of LNC modifiers composed of poly(N-methyl-N-vinyl acetamide), poly(N-vinyl pyrrolidone) or pH-responsive vinylimidazole-based sequence bearing a variety of lipophilic end-groups, namely octadecyl, dioctadecyl or phospholipid groups, for anchoring to the LNC. Decoration of the LNC with these families of poly(N-vinyl amide) derivatives was achieved via both post-insertion and per-formulation methods. This offered valuable and non-toxic LNC protection from opsonization by complement activation, emphasized the benefit of dioctadecyl in the per-formulation approach and highlighted the great potential of poly(N-methyl-N-vinyl acetamide) as PEG alternative. Moreover, incorporation of imidazole moieties in the shell of the carrier imparted pH-responsiveness to the LNC likely to increase the cellular uptake in the acidic tumor microenvironment, opening up new possibilities in the field of active targeting.

Physicochemical Characterization of Ferrocifen Lipid Nanocapsules: Customized Drug Delivery Systems Guided by the Molecular Structure

Ferrocifens, lipophilic organometallic complexes, comprise a biologically active redox motif [ferrocenyl-ene-p-phenol] which confers very interesting cytotoxic properties to this family. However, because of their highly lipophilic nature, a formulation stage is required before being administered in vivo. In recent decades, ferrocifen lipid nanocapsules (LNCs) have been successfully formulated and have demonstrated anticancer activity on multidrug-resistant cancers in several mice and rat models (glioblastoma, breast cancer, and metastatic melanoma). A recent family of ferrocifens (succinimidoalkyl-ferrociphenols, including P722) appears to be most efficacious on several resistant cancer cell lines, with IC₅₀ values in the nanomolar range together with promising in vivo results on murine ovarian cancer models. As LNCs are composed of an oily core (caprylic/capric triglycerides), modulation of the succinimido-ferrociphenol lipophilicity could be a valuable approach toward improving the drug loading in LNCs. As the drug loading of the diphenol P722 in LNCs was low, it was structurally modified to increase its lipophilicity and thereby the payload in LNCs. Chemical modification led to a series of five succinimido-ferrocifens. Results confirmed that these slight structural modifications led to increased drug loading in LNCs for all ferrocifens, with no reduction of their cytotoxicity on the SKOV3 ovarian cancer cell line. Interestingly, encapsulation of two of the ferrocifens, diester P769 and monophenolic ester (E)-P998, led to the formation of a gel. This was unprecedented behavior, a phenomenon that could be rationalized in terms of the positioning of ferrocifens in LNCs as shown by the decrease of interfacial tension measurements at the water/oil interface. Moreover, these results highlighted the importance of obtaining a gel of this particular motif, in which the acetylated phenolic ring and the succinimidoalkyl moieties are mutually cis relative to the central double bond. Promising perspectives to use these ferrocifen-loaded LNCs to treat glioblastoma could be readily envisaged by local application of the gel in the cavity after tumor resection.

Ferrocifen stealth LNCs and conventional chemotherapy: A promising combination against multidrug-resistant ovarian adenocarcinoma

Ovarian cancer is one of the deadliest epithelial malignancies in women, owing to the multidrug resistance that restricts the success of conventional chemotherapy, carboplatin and paclitaxel. High grade serous ovarian carcinoma can be classified into two subtypes, the chemosensitive High OXPHOS and the Low OXPHOS tumour, less sensitive to chemotherapy. This difference of treatment efficacy could be explained by the redox status of these tumours, High OXPHOS exhibiting a chronic oxidative stress and an accumulation of reactive oxygen species. Ferrocifens, bio-organometallic compounds, are believed to be ROS producers with a good cytotoxicity on ovarian cancer cell lines. The aim of this study was to evaluate the in vivo efficacy of ferrocifen stealth lipid nanocapsules on High and Low OXPHOS ovarian Patient-Derived Xenograft models, alone or in combination to standard chemotherapy. Accordingly, two ferrocifens, P53 and P722, were encapsulated in stealth LNCs. The treatment by stealth P722-LNCs in combination with standard chemotherapy induced, with a concentration eight time lower than in stealth P53-LNCs, similar tumour reduction on a Low OXPHOS model, allowing us to conclude that P722 could be a leading ferrocifen to treat ovarian cancer. This combination of treatments may represent a promising synergistic approach to treat resistant ovarian adenocarcinoma.

Recent advances in the therapeutic strategies of glioblastoma multiforme

Glioblastoma multiforme (GBM) is one of the most common, most formidable, and deadliest malignant types of primary astrocytoma with a poor prognosis. At present, the standard of care includes surgical tumor resection, followed by radiation therapy concomitant with chemotherapy and temozolomide. New developments and significant advances in the treatment of GBM have been achieved in recent decades. However, despite the advances, recurrence is often inevitable, and the survival of patients remains low. Various factors contribute to the difficulty in identifying an effective therapeutic option, among which are tumor complexity, the presence of the blood-brain barrier (BBB), and the presence of GBM cancer stem cells, prompting the need for improving existing treatment approaches and investigating new treatment alternatives for ameliorating the treatment strategies of GBM. In this review, we outline some of the most recent literature on the various available treatment options such as surgery, radiotherapy, cytotoxic chemotherapy, gene therapy, immunotherapy, phototherapy, nanotherapy, and tumor treating fields in the treatment of GBM, and we list some of the potential future directions of GBM. The reviewed studies confirm that GBM is a sophisticated disease with several challenges for scientists to address. Hence, more studies and a multimodal therapeutic approach are crucial to yield an effective cure and prolong the survival of GBM patients.

Ferrocifen Loaded Lipid Nanocapsules: A Promising Anticancer Medication against Multidrug Resistant Tumors

Resistance of cancer cells to current chemotherapeutic drugs has obliged the scientific community to seek innovative compounds. Ferrocifens, lipophilic organometallic compounds composed of a tamoxifen scaffold covalently bound to a ferrocene moiety, have shown very interesting antiproliferative, cytotoxic and immunologic effects. The formation of ferrocenyl quinone methide plays a crucial role in the multifaceted activity of ferrocifens. Lipid nanocapsules (LNCs), meanwhile, are nanoparticles obtained by a free organic solvent process. LNCs consist of an oily core surrounded by amphiphilic surfactants and are perfectly adapted to encapsulate these hydrophobic compounds. The different in vitro and in vivo experiments performed with this ferrocifen-loaded nanocarrier have revealed promising results in several multidrug-resistant cancer cell lines such as glioblastoma, breast cancer and metastatic melanoma, alone or in combination with other therapies. This review provides an exhaustive summary of the use of ferrocifen-loaded LNCs as a promising nanomedicine, outlining the ferrocifen mechanisms of action on cancer cells, the nanocarrier formulation process and the in vivo results obtained over the last two decades.

pH-Responsive Lipid Nanocapsules: A Promising Strategy for Improved Resistant Melanoma Cell Internalization

Despite significant advances in melanoma therapy, low response rates and multidrug resistance (MDR) have been described, reducing the anticancer efficacy of the administered molecules. Among the causes to explain these resistances, the decreased intratumoral pH is known to potentiate MDR and to reduce the sensitivity to anticancer molecules. Nanomedicines have been widely exploited as the carriers of MDR reversing molecules. Lipid nanocapsules (LNC) are nanoparticles that have already demonstrated their ability to improve cancer treatment. Here, LNC were modified with novel copolymers that combine N-vinylpyrrolidone (NVP) to impart stealth properties and vinyl imidazole (Vim), providing pH-responsive ability to address classical chemoresistance by improving tumor cell entry. These copolymers could be post-inserted at the LNC surface, leading to the property of going from neutral charge under physiological pH to positive charge under acidic conditions. LNC modified with polymer P5 (C18H37-P(NVP21-co-Vim15)) showed in vitro pH-responsive properties characterized by an enhanced cellular uptake under acidic conditions. Moreover, P5 surface modification led to an increased biological effect by protecting the nanocarrier from opsonization by complement activation. These data suggest that pH-sensitive LNC responds to what is expected from a promising nanocarrier to target metastatic melanoma.

Convection-enhanced drug delivery for glioblastoma: a review

INTRODUCTION

Convection-enhanced delivery (CED) is a method of targeted, local drug delivery to the central nervous system (CNS) that bypasses the blood-brain barrier (BBB) and permits the delivery of high-dose therapeutics to large volumes of interest while limiting associated systemic toxicities. Since its inception, CED has undergone considerable preclinical and clinical study as a safe method for treating glioblastoma (GBM). However, the heterogeneity of both, the surgical procedure and the mechanisms of action of the agents studied-combined with the additional costs of performing a trial evaluating CED-has limited the field's ability to adequately assess the durability of any potential anti-tumor responses. As a result, the long-term efficacy of the agents studied to date remains difficult to assess.

MATERIALS AND METHODS

We searched PubMed using the phrase "convection-enhanced delivery and glioblastoma". The references of significant systematic reviews were also reviewed for additional sources. Articles focusing on physiological and physical mechanisms of CED were included as well as technological CED advances.

RESULTS

We review the history and principles of CED, procedural advancements and characteristics, and outcomes from key clinical trials, as well as discuss the potential future of this promising technique for the treatment of GBM.

CONCLUSION

While the long-term efficacy of the agents studied to date remains difficult to assess, CED remains a promising technique for the treatment of GBM.

Strategies for Improved Intra-arterial Treatments Targeting Brain Tumors: a Systematic Review

Conventional treatments for brain tumors relying on surgery, radiation, and systemic chemotherapy are often associated with high recurrence and poor prognosis. In recent decades, intra-arterial administration of anti-cancer drugs has been considered a suitable alternative drug delivery route to intravenous and oral administration. Intra-arterial administration is believed to offer increasing drug responses by primary and metastatic brain tumors, and to be associated with better median overall survival. By directly injecting therapeutic agents into carotid or vertebral artery, intra-arterial administration rapidly increases intra-tumoral drug concentration but lowers systemic exposure. However, unexpected vascular or neural toxicity has questioned the therapeutic safety of intra-arterial drug administration and limits its widespread clinical application. Therefore, improving targeting and accuracy of intra-arterial administration has become a major research focus. This systematic review categorizes strategies for optimizing intra-arterial administration into five categories: (1) transient blood-brain barrier (BBB)/blood-tumor barrier (BTB) disruption, (2) regional cerebral hypoperfusion for peritumoral hemodynamic changes, (3) superselective endovascular intervention, (4) high-resolution imaging techniques, and (5) others such as cell and gene therapy. We summarize and discuss both preclinical and clinical research, focusing on advantages and disadvantages of different treatment strategies for a variety of cerebral tumor types.

Lipid nanocapsules to enhance drug bioavailability to the central nervous system

The central nervous system (CNS), namely the brain, still remains as the hardest area of the human body to achieve adequate concentration levels of most drugs, mainly due to the limiting behavior of its physical and biological defenses. Lipid nanocapsules emerge as a versatile platform to tackle those barriers, and efficiently delivery different drug payloads due to their numerous advantages. They can be produced in a fast, solvent-free and scalable-up process, and their properties can be fine-tuned for to make an optimal brain drug delivery vehicle. Moreover, lipid nanocapsule surface modification can further improve their bioavailability towards the central nervous system. Coupling these features with alternative delivery methods that stem to disrupt or fully circumvent the blood-brain barrier may fully harness the therapeutic advance that lipid nanocapsules can supply to current treatment options. Thus, this review intends to critically address the development of lipid nanocapsules, as well as to highlight the key features that can be modulated to ameliorate their properties towards the central nervous system delivery, mainly through intravenous methods, and how the pathological microenvironment of the CNS can be taken advantage of. The different routes to promote drug delivery towards the brain parenchyma are also discussed, as well as the synergetic effect that can be obtained by combining modified lipid nanocapsules with new/smart administration routes.

Polymeric Nanoparticles for the Treatment of Malignant Gliomas

Malignant gliomas are one of the deadliest forms of brain cancer and despite advancements in treatment, patient prognosis remains poor, with an average survival of 15 months. Treatment using conventional chemotherapy does not deliver the required drug dose to the tumour site, owing to insufficient blood brain barrier (BBB) penetration, especially by hydrophilic drugs. Additionally, low molecular weight drugs cannot achieve specific accumulation in cancerous tissues and are characterized by a short circulation half-life. Nanoparticles can be designed to cross the BBB and deliver their drugs within the brain, thus improving their effectiveness for treatment when compared to administration of the free drug. The efficacy of nanoparticles can be enhanced by surface PEGylation to allow more specificity towards tumour receptors. This review will provide an overview of the different therapeutic strategies for the treatment of malignant gliomas, risk factors entailing them as well as the latest developments for brain drug delivery. It will also address the potential of polymeric nanoparticles in the treatment of malignant gliomas, including the importance of their coating and functionalization on their ability to cross the BBB and the chemistry underlying that.

Development and characterization of sorafenib-loaded lipid nanocapsules for the treatment of glioblastoma

Anticancer agents that target both tumor cells and angiogenesis are of potential interest for glioblastoma (GB) therapy. One such agent is sorafenib (SFN), a tyrosine kinase inhibitor. However, poor aqueous solubility and undesirable side effects limit its clinical application, including local treatment. We encapsulated SFN in lipid nanocapsules (LNCs) to overcome these drawbacks. LNCs are nanocarriers formulated according to a solvent-free process, using only components that have received regulatory approval. SFN-LNCs had a diameter of 54 ± 1 nm, high encapsulation efficiency (>90%), and a drug payload of 2.11 ± 0.03 mg/g of LNC dispersion. They inhibited in vitro angiogenesis and decreased human U87MG GB cell viability similarly to free SFN. In vivo studies showed that the intratumoral administration of SFN-LNCs or free SFN in nude mice bearing an orthotopic U87MG human GB xenograft decreased the proportion of proliferating cells in the tumor relative to control groups. SFN-LNCs were more effective than free SFN for inducing early tumor vascular normalization, characterized by increases in tumor blood flow and decreases in tumor vessel area. These results highlight the potential of LNCs as delivery systems for SFN. The vascular normalization induced by SFN-LNCs could be used to improve the efficacy of chemotherapy or radiotherapy for treating GB.

Iron Compounds as Anticancer Agents

Many ferrocene complexes have been prepared for their oncological potential. Some derive from molecules with known biological effects (taxanes, podophyllotoxine, artemisine, SAHA, etc.) while others are synthetic molecules selected for their cytotoxic effects (N-alkylaminoferrocenes and ferrocenyl alkylpyridinium). Although these complexes have received a great deal of attention, the field of iron metallodrugs is not limited to them. A number of inorganic complexes of iron(ii) and iron(iii) with possible anticancer effects have also been published, although research into their biological effects is often only at an early stage. This chapter also includes iron chelators, molecules that are administered in non-metallic form but whose cytotoxic species are their coordination complexes of iron generated in vivo. The most emblematic molecule of this family is bleomycin, used as an anticancer agent in many chemotherapies. To these can be added the iron chelates originally synthesized to treat iron overload, some of which have been shown to possess interesting anticancer properties. They have been, and continue to be, the subject of many clinical trials, whether alone or in combination. Thus, the area of iron metallodrugs includes molecules with very different structures and reactivity, studied from a number of different perspectives, but focused on increasing the number of molecules at our disposal for combatting cancer.

Lipid nanocapsules as in vivo oxygen sensors using magnetic resonance imaging

Hypoxia is common occurrence of the tumour microenvironment, wherein heterogeneous gradients of O₂ give rise to tumoural cells which are highly malignant, metastatic, and resistant to therapeutic efforts. Thus, the assessment and imaging of hypoxia is essential for tumour diagnosis and treatment. Magnetic resonance imaging and, more specifically, the quantitative assessment of longitudinal relaxation time enhancement, was shown to enable the mapping of oxygen in tumours with increased sensitivity for lipids as compared to water signal. Unfortunately, this can only be applied to tumours with high lipid content. To overcome this issue, we propose the use of lipid nanocapsules (LNCs). LNCs have been demonstrated as excellent core-shell nanocarriers, wherein the lipidic-core is used for lipophilic drug encapsulation, enabling treatment of highly malignant tumours. Herein, however, we exploited the lipidic-core of the LNCs to develop a simple but effective technique to increase the lipidic content within tissues to enable the assessment and mapping of pO₂. LNCs were prepared using the phase-inversion technique to produce 60 nm sized nanoparticles, and in vitro studies demonstrated the permeability and responsiveness of LNCs to O₂. To evaluate the ability of LNCs to respond to changes in pO₂in vivo, after a hyperoxic challenge, three animal models, namely a normal tissue model (gastrocnemius muscle tissue) and two tumour tissue models (subcutaneous fibrosarcoma and intracerebral glioblastoma) were explored. LNCs were found to be responsive to variation of O₂in vivo. Moreover, the use of MRI enabled the mapping of oxygen gradients and heterogeneity within tumours.

Enhanced and preferential internalization of lipid nanocapsules into human glioblastoma cells: effect of a surface-functionalizing NFL peptide

Increasing intracellular drug concentration using nanocarriers can be a potential strategy to improve efficacy against glioblastoma (GBM). Here, the fluorescent-labelled NFL-TBS·40-63 peptide (fluoNFL) concentration on a lipid nanocapsule (LNC) was studied to enhance nanovector internalization into human GBM cells. LNC surface-functionalization with various fluoNFL concentrations was performed by adsorption. LNC size and surface charge altered gradually with increasing peptide concentration, but their complement protein consumption remained low. Desorption of fluoNFL from the LNC surface was found to be slow. Furthermore, it was observed that the rate and extent of LNC internalization in the U87MG human glioblastoma cells were dependent on the surface-functionalizing fluoNFL concentration. In addition, we showed that the uptake of fluoNFL-functionalized LNCs was preferential towards U87MG cells compared to healthy human astrocytes. The fluoNFL-functionalized LNC internalization into the U87MG cells was energy-dependent and occurred possibly by macropinocytosis and clathrin-mediated and caveolin-mediated endocytosis. A new ferrocifen-type molecule (FcTriOH), as a potent anticancer candidate, was then encapsulated in the LNCs and the functionalization improved its in vitro efficacy compared to other tested formulations against U87MG cells. In the preliminary study, on subcutaneous human GBM tumor model in nude mice, a significant reduction of relative tumor volume was observed at one week after the second intravenous injection with FcTriOH-loaded LNCs. These results showed that enhancing NFL peptide concentration on the LNC surface is a promising approach for increased and preferential nanocarrier internalization into human GBM cells, and the FcTriOH-loaded LNCs are a promising therapy approach for GBM.

Convection-Enhanced Delivery

Convection-enhanced delivery (CED) is a promising technique that generates a pressure gradient at the tip of an infusion catheter to deliver therapeutics directly through the interstitial spaces of the central nervous system. It addresses and offers solutions to many limitations of conventional techniques, allowing for delivery past the blood-brain barrier in a targeted and safe manner that can achieve therapeutic drug concentrations. CED is a broadly applicable technique that can be used to deliver a variety of therapeutic compounds for a diversity of diseases, including malignant gliomas, Parkinson's disease, and Alzheimer's disease. While a number of technological advances have been made since its development in the early 1990s, clinical trials with CED have been largely unsuccessful, and have illuminated a number of parameters that still need to be addressed for successful clinical application. This review addresses the physical principles behind CED, limitations in the technique, as well as means to overcome these limitations, clinical trials that have been performed, and future developments.

Strategies for transporting nanoparticles across the blood-brain barrier

The existence of blood-brain barrier (BBB) hampers the effective treatment of central nervous system (CNS) diseases. Almost all macromolecular drugs and more than 98% of small molecule drugs cannot pass the BBB. Therefore, the BBB remains a big challenge for delivery of therapeutics to the central nervous system. With the structural and mechanistic elucidation of the BBB under both physiological and pathological conditions, it is now possible to design delivery systems that could cross the BBB effectively. Because of their advantageous properties, nanoparticles have been widely deployed for brain-targeted delivery. This review paper presents the current understanding of the BBB under physiological and pathological conditions, and summarizes strategies and systems for BBB crossing with a focus on nanoparticle-based drug delivery systems. In summary, with wider applications and broader prospection the treatment of brain targeted therapy, nano-medicines have proved to be more potent, more specific and less toxic than traditional drug therapy.

Nano-structures mediated co-delivery of therapeutic agents for glioblastoma treatment: A review

Glioblastoma is a malignant brain tumor and leads to death in most patients. Chemotherapy is a common method for brain cancer in clinics. However, the recent advancements in the chemotherapy of brain tumors have not been efficient enough. With the advancement of nanotechnology, the used drugs can enhance chemotherapy efficiency and increase the access to brain cancers. Combination of therapeutic agents has been recently attracted great attention for glioblastoma chemotherapy. One of the early benefits of combination therapies is the high potential to provide synergistic effects and decrease adverse side effects associated with high doses of single anticancer drugs. Therefore, brain tumor treatments with combination drugs can be considered as a crucial approach for avoiding tumor growth. This review investigates current progress in nano-mediated co-delivery of therapeutic agents with focus on glioblastoma chemotherapy prognosis.

Application of Nanomedicine to the CNS Diseases

Drug delivery to the brain is a challenge because of the many mechanisms that protect the brain from the entry of foreign substances. Numerous molecules which could be active against brain disorders are not clinically useful due to the presence of the blood-brain barrier. Nanoparticles can be used to deliver these drugs to the brain. Encapsulation within colloidal systems can allow the passage of nontransportable drugs across this barrier by masking their physicochemical properties. It should be noted that the status of the blood-brain barrier is different depending on the brain disease. In fact, in some pathological situations such as tumors or inflammatory disorders, its permeability is increased allowing very easy translocation of carriers. This chapter gathers the promising results obtained by using nanoparticles as drug delivery systems with the aim to improve the therapy of some CNS diseases such as brain tumor, Alzheimer's disease, and stroke. The data show that several approaches can be investigated: (1) carrying drug through a permeabilized barrier, (2) crossing the barrier thanks to receptor-mediated transcytosis pathway in order to deliver drug into the brain parenchyma, and also (3) targeting and treating the endothelial cells themselves to preserve locally the brain tissue. The examples given in this chapter contribute to demonstrate that delivering drugs into the brain is one of the most promising applications of nanotechnology in clinical neuroscience.

Convection-enhanced delivery to the central nervous system

Convection-enhanced delivery (CED) is a bulk flow–driven process. Its properties permit direct, homogeneous, targeted perfusion of CNS regions with putative therapeutics while bypassing the blood-brain barrier. Development of surrogate imaging tracers that are co-infused during drug delivery now permit accurate, noninvasive real-time tracking of convective infusate flow in nervous system tissues. The potential advantages of CED in the CNS over other currently available drug delivery techniques, including systemic delivery, intrathecal and/or intraventricular distribution, and polymer implantation, have led to its application in research studies and clinical trials. The authors review the biophysical principles of convective flow and the technology, properties, and clinical applications of convective delivery in the CNS.

Inhibition of ectopic glioma tumor growth by a potent ferrocenyl drug loaded into stealth lipid nanocapsules

In this work, a novel ferrocenyl complex (ansa-FcdiOH) was assessed for brain tumor therapy through stealth lipid nanocapsules (LNCs). Stealth LNCs, prepared according to a one-step process, showed rapid uptake by cancer cells and extended blood circulation time. The ferrocenyl complex was successfully encapsulated into these LNCs measuring 40 nm with a high loading capacity (6.4%). In vitro studies showed a potent anticancer effect of ansa-FcdiOH on 9L cells with a low IC50 value (0.1 μM) associated with an oxidative stress and a dose-dependent alteration of the cell cycle. Repeated intravenous injections of stealth ansa-FcdiOH LNCs in ectopic glioma bearing rats induced a significant tumor growth inhibition, supported by a reduced number of proliferative cells in tumors compared to control group. Additionally, no liver damage was observed in treated animals. These results indicated that stealth ansa-FcdiOH LNCs might be considered as a potential new approach for cancer chemotherapy.

FROM THE CLINICAL EDITOR

In this study, a novel ferrocenyl complex was assessed for brain tumor therapy through stealth lipid nanocapsules, demonstrating no liver damage, and superior tumor volume reduction compared to saline and stealth lipid nanocapsules alone in an ectopic glioma model.

Patented nanomedicines for the treatment of brain tumors

Patients affected by malignant brain tumors present an extremely poor prognosis, notwithstanding improvements in surgery techniques and therapeutic protocols. Brain tumor treatment has been principally hampered by limited drug delivery across the blood–brain barrier (BBB). An efficacious chemotherapeutic treatment requires a pharmacological agent that can penetrate the BBB and target neoplastic cells. Nanotechnology involves the design, synthesis and characterization of materials that have a functional organization in at least one dimension on the nanometer scale. Nanoparticle systems can represent optimal devices for delivery of various drugs into the brain across the BBB. Nanoparticle drug-delivery systems can also be used to provide targeted delivery of drugs, improve bioavailability and sustain release of drugs for systemic delivery. In this patent review, the recent studies of certain nanoparticle systems in treatment of brain tumors are summarized. Common nanoparticles systems include polymeric nanoparticles, lipid nanoparticles and inorganic nanoparticles. Various patents of nanoparticle systems able to across the BBB to target brain tumors are also reported and discussed.

Developments in the use of nanocapsules in oncology

The application of nanotechnology to medicine can provide important benefits, especially in oncology, a fact that has resulted in the emergence of a new field called Nanooncology. Nanoparticles can be engineered to incorporate a wide variety of chemotherapeutic or diagnostic agents. A nanocapsule is a vesicular system that exhibits a typical core-shell structure in which active molecules are confined to a reservoir or within a cavity that is surrounded by a polymer membrane or coating. Delivery systems based on nanocapsules are usually transported to a targeted tumor site and then release their contents upon change in environmental conditions. An effective delivery of the therapeutic agent to the tumor site and to the infiltrating tumor cells is difficult to achieve in many cancer treatments. Therefore, new devices are being developed to facilitate intratumoral distribution, to protect the active agent from premature degradation and to allow its sustained and controlled release. This review focuses on recent studies on the use of nanocapsules for cancer therapy and diagnosis.

Brain tumour targeting strategies via coated ferrociphenol lipid nanocapsules

In this study, a new active targeting strategy to favour ferrociphenol (FcdiOH) internalisation into brain tumour cells was developed by the use of lipid nanocapsules (LNCs) coated with a cell-internalising peptide (NFL-TBS.40-63 peptide) that interacts with tubulin-binding sites. In comparison, OX26 murine monoclonal antibodies (OX26-MAb) targeting transferrin receptors were also inserted onto the LNC surface. The incorporation of OX26 or peptide did not influence the in vitro antiproliferative effect of FcdiOH-LNCs on the 9L cells since their IC50 values were found in the same range. In vivo, intracerebral administration of OX26-FcdiOH-LNCs or peptide-FcdiOH-LNCs by convection enhanced delivery did not enhance the animal median survival time in comparison with untreated rats (25 days). Interestingly, intra-carotid treatment with peptide-FcdiOH-LNCs led to an ameliorated survival time of treated rats with the presence of animals surviving until days 35, 40 and 44. Such results were not obtained with OX26-MAbs, demonstrating the benefit of NFL-TBS.40-63 peptide as an active ligand for peripheral drug delivery to the brain tumours.