Targeting delivery of etoposide to inhibit the growth of human glioblastoma multiforme using lactoferrin- and folic acid-grafted poly(lactide-co-glycolide) nanoparticles

Brain targeted lactoferrin coated lipid nanocapsules for the combined effects of apocynin and lavender essential oil in PTZ induced seizures

Apocynin (APO) is a plant derived antioxidant exerting specific NADPH oxidase inhibitory action substantiating its neuroprotective effects in various CNS disorders, including epilepsy. Due to rapid elimination and poor bioavailability, treatment with APO is challenging. Correspondingly, novel APO-loaded lipid nanocapsules (APO-LNC) were formulated and coated with lactoferrin (LF-APO-LNC) to improve br ain targetability and prolong residence time. Lavender oil (LAV) was incorporated into LNC as a bioactive ingredient to act synergistically with APO in alleviating pentylenetetrazol (PTZ)-induced seizures. The optimized LF-APO-LAV/LNC showed a particle size 59.7 ± 4.5 nm with narrow distribution and 6.07 ± 1.6mV zeta potential) with high entrapment efficiency 92 ± 2.4% and sustained release (35% in 72 h). Following subcutaneous administration, LF-APO-LAV/LNC brought about ⁓twofold increase in plasma AUC and MRT compared to APO. A Log BB value of 0.2 ± 0.14 at 90 min reflects increased brain accumulation. In a PTZ-induced seizures rat model, LF-APO-LAV/LNC showed a Modified Racine score of 0.67 ± 0.47 with a significant increase in seizures latency and decrease in duration. Moreover, oxidant/antioxidant capacity and inflammatory markers levels in brain tissue were significantly improved. Histopathological and immunohistochemical assessment of brain tissue sections further supported these findings. The results suggest APO/LAV combination in LF-coated LNC as a promising approach to counteract seizures.

Etoposide-loaded lipopolymer nanoparticles promote Smac minetic activity against inhibitor of apoptosis protein for glioblastoma treatment

Encapsulated BV6 and SM164, two bivalent second mitochondria-derived activator of caspase (Smac) mimetics, in etoposide (ETO)-lipopolymer nanoparticles (NPs) have been developed to deplete inhibitor of apoptosis proteins (IAP), impair DNA, and produce antagonistic effects on glioblastoma multiforme (GBM) in nude mice. The NPs, composed of cocoa butter (CB) and polyvinyl alcohol (PVA), were stabilized by glycerol monostearate and Pluronic F-127, and grafted with transferrin (Tf) and wheat germ agglutinin (WGA) to dock the blood-brain barrier (BBB) and degenerated dopaminergic neurons. The dual-targeting NPs increased the BBB permeability of BV6, SM164 and ETO via recognizing Tf receptor (TfR) and N-acetylglucosamine that are abundantly expressed on brain microvascular endothelial cells. The sustained release of BV6, SM164 and ETO from CB-PVA-NPs for 48 h resulted in a reduction of about 40 % in the viability of U87MG cells and human brain cancer stem cells. Hematoxylin and eosin staining of the brain in GBM mice revealed atypical mitosis of cancer cells and a considerable decrease in tumor cell density after treatment with Tf-WGA-BV6-SM164-ETO-NPs. Compared to untreated mice, the current ETO preparation carrying Smac mimetics reduced cellular IAP-1 expression to about 33 % and X-linked IAP expression to about 42 %, while enhanced about 3.8-fold caspase-3, indicating the effectiveness of the nanocarriers in accelerating apoptosis of GBM cells. Tf-WGA-CB-PVA-NPs can be promising to upgrade BV6 and SM164 activity by ETO in clinical trials for GBM management.

Receptor-Assisted Nanotherapeutics for Overcoming the Blood-Brain Barrier

Blood-brain barrier (BBB) is a distinguishing checkpoint that segregates peripheral organs from neural compartment. It protects the central nervous system from harmful ambush of antigens and pathogens. Owing to such explicit selectivity, the BBB hinders passage of various neuroprotective drug molecules that escalates into poor attainability of neuroprotective agents towards the brain. However, few molecules can surpass the BBB and gain access in the brain parenchyma by exploiting surface transporters and receptors. For successful development of brain-targeted therapy, understanding of BBB transporters and receptors is crucial. This review focuses on the transporter and receptor-based mechanistic pathway that can be manoeuvred for better comprehension of reciprocity of receptors and nanotechnological vehicle delivery. Nanotechnology has emerged as one of the expedient noninvasive approaches for brain targeting via manipulating the hurdle of the BBB. Various nanovehicles are being reported for brain-targeted delivery such as nanoparticles, nanocrystals, nanoemulsion, nanolipid carriers, liposomes and other nanovesicles. Nanotechnology-aided brain targeting can be a strategic approach to circumvent the BBB without altering the inherent nature of the BBB.

A receptor-mediated landscape of druggable and targeted nanomaterials for gliomas

Gliomas are the most common type of brain cancer, and among them, glioblastoma multiforme (GBM) is the most prevalent (about 60% of cases) and the most aggressive type of primary brain tumor. The treatment of GBM is a major challenge due to the pathophysiological characteristics of the disease, such as the presence of the blood-brain barrier (BBB), which prevents and regulates the passage of substances from the bloodstream to the brain parenchyma, making many of the chemotherapeutics currently available not able to reach the brain in therapeutic concentrations, accumulating in non-target organs, and causing considerable adverse effects for the patient. In this scenario, nanocarriers emerge as tools capable of improving the brain bioavailability of chemotherapeutics, in addition to improving their biodistribution and enhancing their uptake in GBM cells. This is possible due to its nanometric size and surface modification strategies, which can actively target nanocarriers to elements overexpressed by GBM cells (such as transmembrane receptors) related to aggressive development, drug resistance, and poor prognosis. In this review, an overview of the most frequently overexpressed receptors in GBM cells and possible approaches to chemotherapeutic delivery and active targeting using nanocarriers will be presented.

Inhibition of DAMP actions in the tumoral microenvironment using lactoferrin-glycyrrhizin conjugate for glioblastoma therapy

BACKGROUND

High-mobility group box-1 (HMGB1) released from the tumor microenvironment plays a pivotal role in the tumor progression. HMGB1 serves as a damaged-associated molecular pattern (DAMP) that induces tumor angiogenesis and its development. Glycyrrhizin (GL) is an effective intracellular antagonist of tumor released HMGB1, but its pharmacokinetics (PK) and delivery to tumor site is deficient. To address this shortcoming, we developed lactoferrin-glycyrrhizin (Lf-GL) conjugate.

METHODS

Biomolecular interaction between Lf-GL and HMGB1 was evaluated by surface plasmon resonance (SPR) binding affinity assay. Inhibition of tumor angiogenesis and development by Lf-GL attenuating HMGB1 action in the tumor microenvironment was comprehensively evaluated through in vitro, ex vivo, and in vivo. Pharmacokinetic study and anti-tumor effects of Lf-GL were investigated in orthotopic glioblastoma mice model.

RESULTS

Lf-GL interacts with lactoferrin receptor (LfR) expressed on BBB and GBM, therefore, efficiently inhibits HMGB1 in both the cytoplasmic and extracellular regions of tumors. Regarding the tumor microenvironment, Lf-GL inhibits angiogenesis and tumor growth by blocking HMGB1 released from necrotic tumors and preventing recruitment of vascular endothelial cells. In addition, Lf-GL improved the PK properties of GL approximately tenfold in the GBM mouse model and reduced tumor growth by 32%. Concurrently, various biomarkers for tumor were radically diminished.

CONCLUSION

Collectively, our study demonstrates a close association between HMGB1 and tumor progression, suggesting Lf-GL as a potential strategy for coping with DAMP-related tumor microenvironment. HMGB1 is a tumor-promoting DAMP in the tumor microenvironment. The high binding capability of Lf-GL to HMGB1 inhibits tumor progression cascade such as tumor angiogenesis, development, and metastasis. Lf-GL targets GBM through interaction with LfR and allows to arrest HMGB1 released from the tumor microenvironment. Therefore, Lf-GL can be a GBM treatment by modulating HMGB1 activity.

Lactoferrin and Nanotechnology: The Potential for Cancer Treatment

Lactoferrin (Lf)-a glycoprotein of the transferrin family-has been investigated as a promising molecule with diverse applications, including infection inhibition, anti-inflammation, antioxidant properties and immune modulation. Along with that, Lf was found to inhibit the growth of cancerous tumors. Owing to unique properties such as iron-binding and positive charge, Lf could interrupt the cancer cell membrane or influence the apoptosis pathway. In addition, being a common mammalian excretion, Lf offers is promising in terms of targeting delivery or the diagnosis of cancer. Recently, nanotechnology significantly enhanced the therapeutic index of natural glycoproteins such as Lf. Therefore, in the context of this review, the understanding of Lf is summarized and followed by different strategies of nano-preparation, including inorganic nanoparticles, lipid-based nanoparticles and polymer-based nanoparticles in cancer management. At the end of the study, the potential future applications are discussed to pave the way for translating Lf into actual usage.

Interpreting the Therapeutic Efficiency of Multifunctional Hybrid Nanostructure against Glioblastoma

Glioblastoma is considered the most fatal malignant brain tumor that starts from the central nervous system (CNS), where the blood-brain barrier (BBB) remains the biggest challenge for active targeting of drugs in malignant brain tumor. Thereby, we have designed a paclitaxel PTX@ANG/FA-NPs hybrid novel nanodrug delivery system that can overcome the clinical BBB. The structural and morphological characterization of PTX@ANG/FA-NPs confirmed successful synthesis of nanomicelles with the size range of about 160 to 170 nm. The overall repressive effect of PTX@ANG/FA-NPs on human glioblastoma U251 cells was 1.2-times that of PTX alone. In vitro cellular uptake assay also demonstrated that the dual-targeted nanoparticles (NPs) were more easily taken up by glioblastoma U251 cells. Although the antiglioblastoma activity was confirmed by cell migration assay, apoptosis assay, and cellular uptake assay, the absorption was studied by in vivo fluorescence imaging and brain distribution. The synthesized PTX@ANG/FA-NPs probe significantly inhibited the migration of U251 within the cells and promoted the apoptosis process. Moreover, the RhB@ANG/FA-NPs and PTX@ANG/FA-NPs showed higher accumulating potential at sites of tumor BBB disruption. The novel nanodrug delivery system mediated enhanced distribution of drugs at the targeted site for therapeutics efficacies against glioblastomas across the BBB.

Nanoconstructs for theranostic application in cancer: Challenges and strategies to enhance the delivery

Nanoconstructs are made up of nanoparticles and ligands, which can deliver the loaded cargo at the desired site of action. Various nanoparticulate platforms have been utilized for the preparation of nanoconstructs, which may serve both diagnostic as well as therapeutic purposes. Nanoconstructs are mostly used to overcome the limitations of cancer therapies, such as toxicity, nonspecific distribution of the drug, and uncontrolled release rate. The strategies employed during the design of nanoconstructs help improve the efficiency and specificity of loaded theranostic agents and make them a successful approach for cancer therapy. Nanoconstructs are designed with a sole purpose of targeting the requisite site, overcoming the barriers which hinders its right placement for desired benefit. Therefore, instead of classifying modes for delivery of nanoconstructs as actively or passively targeted systems, they are suitably classified as autonomous and nonautonomous types. At large, nanoconstructs offer numerous benefits, however they suffer from multiple challenges, too. Hence, to overcome such challenges computational modelling methods and artificial intelligence/machine learning processes are being explored. The current review provides an overview on attributes and applications offered by nanoconstructs as theranostic agent in cancer.

Carborane-Containing Folic Acid bis-Amides: Synthesis and In Vitro Evaluation of Novel Promising Agents for Boron Delivery to Tumour Cells

The design of highly selective low-toxic, low-molecular weight agents for boron delivery to tumour cells is of decisive importance for the development of boron neutron capture therapy (BNCT), a modern efficient combined method for cancer treatment. In this work, we developed a simple method for the preparation of new closo- and nido-carborane-containing folic acid bis-amides containing 18-20 boron atoms per molecule. Folic acid derivatives containing nido-carborane residues were characterised by high water solubility, low cytotoxicity, and demonstrated a good ability to deliver boron to tumour cells in in vitro experiments (up to 7.0 µg B/10⁶ cells in the case of U87 MG human glioblastoma cells). The results obtained demonstrate the high potential of folic acid-nido-carborane conjugates as boron delivery agents to tumour cells for application in BNCT.

Selective targeting of the novel CK-10 nanoparticles to the MDA-MB-231 breast cancer cells

The main objective of this project was to formulate novel decorated amphiphilic PLGA nanoparticles aiming for the selective delivery of the novel peptide (CK-10) to the cancerous/tumor tissue. Novel modified microfluidic techniques were used to formulate the nanoparticles. This technique was modified by using of Nano Assemblr associated with salting out of the organic solvent using K₂HPO₄. This modification is associated with higher peptide loading efficiencies, smaller size and higher uniformity. Size, zeta potential & qualitative determination of the adsorbed targeting ligands were measured by dynamic light scattering and laser anemometry techniques using the zeta sizer. Quantitative estimation of the adsorbed targeting ligands was done by colorimetry and spectrophotometric techniques. Qualitative and quantitative uptakes of the various PLGA nanoparticles were examined by the fluorescence microscope and the flow cytometer while the cytotoxic effect of the nanoparticles was measured by the colorimetric MTT assay. PLGA/poloxamer.FA, PLGA/poloxamer.HA, and PLGA/poloxamer.Tf have breast cancer MDA. MB321 cellular uptakes 83.8, 75.43 & 69.37 % which are higher than those of the PLGA/B cyclodextrin.FA, PLGA/B cyclodextrin.HA and PLGA/B cyclodextrin.Tf 80.87, 74.47 & 64.67 %. Therefore, PLGA/poloxamer.FA and PLGA/poloxamer.HA show higher cytotoxicity than PLGA/ poloxamer.Tf with lower breast cancer MDA-MB-231 cell viabilities 30.74, 39.15 & 49.23 %, respectively. The design of novel decorated amphiphilic CK-10 loaded PLGA nanoparticles designed by the novel modified microfluidic technique succeeds in forming innovative anticancer formulations candidates for therapeutic use in aggressive breast cancers.

Development of Encapsulation Strategies and Composite Edible Films to Maintain Lactoferrin Bioactivity: A Review

Lactoferrin (LF) is a whey protein with various and valuable biological activities. For this reason, LF has been used as a supplement in formula milk and functional products. However, it must be considered that the properties of LF can be affected by technological treatments and gastrointestinal conditions. In this article, we have revised the literature published on the research done during the last decades on the development of various technologies, such as encapsulation or composite materials, to protect LF and avoid its degradation. Multiple compounds can be used to conduct this protective function, such as proteins, including those from milk, or polysaccharides, like alginate or chitosan. Furthermore, LF can be used as a component in complexes, nanoparticles, hydrogels and emulsions, to encapsulate, protect and deliver other bioactive compounds, such as essential oils or probiotics. Additionally, LF can be part of systems to deliver drugs or to apply certain therapies to target cells expressing LF receptors. These systems also allow improving the detection of gliomas and have also been used for treating some pathologies, such as different types of tumours. Finally, the application of LF in edible and active films can be effective against some contaminants and limit the increase of the natural microbiota present in meat, for example, becoming one of the most interesting research topics in food technology.

Development of Polymer-Based Nanoformulations for Glioblastoma Brain Cancer Therapy and Diagnosis: An Update

Brain cancers, mainly high-grade gliomas/glioblastoma, are characterized by uncontrolled proliferation and recurrence with an extremely poor prognosis. Despite various conventional treatment strategies, viz., resection, chemotherapy, and radiotherapy, the outcomes are still inefficient against glioblastoma. The blood–brain barrier is one of the major issues that affect the effective delivery of drugs to the brain for glioblastoma therapy. Various studies have been undergone in order to find novel therapeutic strategies for effective glioblastoma treatment. The advent of nanodiagnostics, i.e., imaging combined with therapies termed as nanotheranostics, can improve the therapeutic efficacy by determining the extent of tumour distribution prior to surgery as well as the response to a treatment regimen after surgery. Polymer nanoparticles gain tremendous attention due to their versatile nature for modification that allows precise targeting, diagnosis, and drug delivery to the brain with minimal adverse side effects. This review addresses the advancements of polymer nanoparticles in drug delivery, diagnosis, and therapy against brain cancer. The mechanisms of drug delivery to the brain of these systems and their future directions are also briefly discussed.

Nanoparticles for Targeted Brain Drug Delivery: What Do We Know?

The blood-brain barrier (BBB) is a barrier that separates the blood from the brain tissue and possesses unique characteristics that make the delivery of drugs to the brain a great challenge. To achieve this purpose, it is necessary to design strategies to allow BBB passage, in order to reach the brain and target the desired anatomic region. The use of nanomedicine has great potential to overcome this problem, since one can modify nanoparticles with strategic molecules that can interact with the BBB and induce uptake through the brain endothelial cells and consequently reach the brain tissue. This review addresses the potential of nanomedicines to treat neurological diseases by using nanoparticles specially developed to cross the BBB.

Facile synthesis of lactoferrin conjugated ultra small large pore silica nanoparticles for the treatment of glioblastoma

The blood brain barrier (BBB) and blood tumour barrier (BTB) remain a major roadblock for delivering therapies to treat brain cancer. Amongst brain cancers, glioblastoma (GBM) is notoriously difficult to treat due to the challenge of delivering chemotherapeutic drugs across the BBB and into the tumour microenvironment. Consequently, GBM has high rates of tumour recurrence. Currently, limited numbers of chemotherapies are available that can cross the BBB to treat GBM. Nanomedicine is an attractive solution for treating GBM as it can augment drug penetration across the BBB and into the heterogeneous tumour site. However, very few nanomedicines exist that can easily overcome both the BBB and BTB owing to difficulty in synthesizing nanoparticles that meet the small size and surface functionality restrictions. In this study, we have developed for the first-time, a room temperature protocol to synthesise ultra-small size with large pore silica nanoparticles (USLP, size ∼30 nm, pore size >7 nm) with the ability to load high concentrations of chemotherapeutic drugs and conjugate a targeting moiety to their surface. The nanoparticles were conjugated with lactoferrin (>80 kDa), whose receptors are overexpressed by both the BBB and GBM, to achieve additional active targeting. Lactoferrin conjugated USLP (USLP-Lf) were loaded with doxorubicin - a chemotherapy agent that is known to be highly effective against GBM in vitro but cannot permeate the BBB. USLP-Lf were able to selectively permeate the BBB in vitro, and were effectively taken up by glioblastoma U87 cells. When compared to the uncoated USLP-NPs, the coating with lactoferrin significantly improved penetration of USLP into U87 tumour spheroids (after 12 hours at 100 μm distance, RFU value 19.58 vs. 49.16 respectively). Moreover, this USLP-Lf based delivery platform improved the efficacy of doxorubicin-mediated apoptosis of GBM cells in both 2D and 3D models. Collectively, our new nano-platform has the potential to overcome both the BBB and BTB to treat GBM more effectively.

Lactoferrin-tethered betulinic acid nanoparticles promote rapid delivery and cell death in triple negative breast and laryngeal cancer cells

Cancer management presents multifarious problems. Triple negative breast cancer (TNBC) is associated with inaccurate prognosis and limited chemotherapeutic options. Betulinic acid (BA) prevents angiogenesis and causes apoptosis of TNBC cells. NIH recommends BA for rapid access in cancer chemotherapy because of its cell-specific toxicity. BA however faces major challenges in therapeutic practices due to its limited solubility and cellular entree. We report lactoferrin (Lf) attached BA nanoparticles (Lf-BAnp) for rapid delivery in triple negative breast (MDA-MB-231) and laryngeal (HEp-2) cancer cell types. Lf association was confirmed by SDS-PAGE and FT-IR analysis. Average hydrodynamic size of Lf-BAnp was 147.7 ± 6.20 nm with ζ potential of -28.51 ± 3.52 mV. BA entrapment efficiency was 75.38 ± 2.70% and the release mechanism followed non-fickian pattern. Impact of Lf-BAnp on cell cycle and cytotoxicity of triple negative breast cancer and its metastatic site laryngeal cancer cell lines were analyzed. Lf-BAnp demonstrated strong anti-proliferative and cytotoxic effects, along with increased sub-G₁ population and reduced number of cells in G₁ and G₂/M phases of the cell cycle, confirming reduced cell proliferation and significant cell death. Speedy intracellular entry of Lf-BAnp occurred within 30 min. Lf-BAnp design was explored for the first time as safer chemotherapeutic arsenals against complex TNBC conditions.

Temozolomide nano enabled medicine: promises made by the nanocarriers in glioblastoma therapy

Glioblastoma multiforme (GBM) is abnormal cell proliferation of glial cells. GBM is the grade IV glioma brain cancer which is life-threatening to many individuals affected by this cancer. The DNA alkylating agent Temozolomide (TMZ) has the distinctiveness of being FDA approved anticancer drug for the first line treatment for GBM. However, treatment of GBM still remains a challenge. This is attributed to TMZ's toxic nature, severe side effects, and fast degradation in vivo. In addition, the lack of targeting ability increases the chances of systemic toxicities. A nano enabled targeted delivery system not only improves the efficiency of TMZ by making it cross the blood brain barrier, have specificity to target, but also reduces toxicity to healthy tissues. Over the last decade the significant advances in the area of nanotechnology applied to medicine have developed many multifunctional therapeutics. In this context, the present review article comprehends the significant progress in the field of TMZ loaded nanocarriers showing promise for futuristic nanomedicine therapies in treating GBM.

Targeting CD146 using folic acid-conjugated nanoparticles and suppression of tumor growth in a mouse glioma model

OBJECTIVE

Glioma stem cells (GSCs) are responsible for tumor initiation, therapeutic resistance, and recurrence. CD146 is mainly expressed in dividing GSCs and regulates cell cycle progression. However, the evaluation of the efficacy of targeted therapy against CD146 in vivo remains to be investigated. In this study, the authors aimed to develop gene therapy targeting GSCs using chitosan oligosaccharide lactate (COL) nanoparticles (NPs) conjugated with folic acid-polyethylene glycol (FA-PEG-COL NPs) for in vitro and in vivo delivery of CD146 small-interfering RNA (siCD146) and to determine the effect of CD146 knockdown on tumor growth.

METHODS

To examine the uptake of NPs by tumor cells, immunofluorescence staining, flow cytometry, and in vivo imaging were performed. The knockdown effect of siCD146 was measured by western blot and water-soluble tetrazolium salt-8 assay in mouse glioma cells. The efficacy of siRNA therapy-targeted GSCs was evaluated by monitoring tumor growth through in vivo imaging and histological analysis.

RESULTS

In vivo accumulation of the FA-PEG-COL NPs in subcutaneous and intracranial gliomas following NP administration via a mouse tail vein was observed. Additionally, in vitro delivery of siCD146 ionically cross-linked NPs, reduced CD146 levels, and suppressed growth in the glioma tumor sphere. Evaluation of the in vivo therapeutic effects of siCD146-cross-linked NPs in a mouse glioma model revealed significant suppression of intracranial tumor growth, with complete removal of the tumor observed in some mice on histological examination. Furthermore, delivery of siCD146 significantly reduced the Ki-67 index in residual tumor tissues relative to that in control mice.

CONCLUSIONS

CD146 is a potential therapeutic target, and folic acid-conjugated NPs delivering siRNA may facilitate gene therapy in malignant gliomas.

PLGA Nanoparticle-Based Formulations to Cross the Blood-Brain Barrier for Drug Delivery: From R&D to cGMP

The blood–brain barrier (BBB) is a natural obstacle for drug delivery into the human brain, hindering treatment of central nervous system (CNS) disorders such as acute ischemic stroke, brain tumors, and human immunodeficiency virus (HIV)-1-associated neurocognitive disorders. Poly(lactic-co-glycolic acid) (PLGA) is a biocompatible polymer that is used in Food and Drug Administration (FDA)-approved pharmaceutical products and medical devices. PLGA nanoparticles (NPs) have been reported to improve drug penetration across the BBB both in vitro and in vivo. Poly(ethylene glycol) (PEG), poly(vinyl alcohol) (PVA), and poloxamer (Pluronic) are widely used as excipients to further improve the stability and effectiveness of PLGA formulations. Peptides and other linkers can be attached on the surface of PLGA to provide targeting delivery. With the newly published guidance from the FDA and the progress of current Good Manufacturing Practice (cGMP) technologies, manufacturing PLGA NP-based drug products can be achieved with higher efficiency, larger quantity, and better quality. The translation from bench to bed is feasible with proper research, concurrent development, quality control, and regulatory assurance.

Cytotoxicity of targeted PLGA nanoparticles: a systematic review

Recent advances in nanotechnology have contributed tremendously to the development and revolutionizing of drug delivery systems in the field of nanomedicine. In particular, targeting nanoparticles based on biodegradable poly(lactic-co-glycolic acid) (PLGA) polymers have gained much interest. However, PLGA nanoparticles remain of concern for their effectiveness against cancer cells and their toxicity to normal cells. The aim of this systematic review is to identify a promising targeting PLGA nanoformulation based on the comparison study of their cytotoxicity potency in different cell lines. A literature search was conducted through the databases of Google Scholar, PubMed, ScienceDirect, Scopus and SpringerLink. The sources studied were published between 2009 and 2019, and a variety of keywords were utilized. In total, 81 manuscripts that met the inclusion and exclusion criteria were selected for analysis based on their cytotoxicity, size, zeta potential, year of publication, type of ligand, active compounds and cell line used. The half maximal inhibitory concentration (IC50) for cytotoxicity was the main measurement in this data extraction, and the SI units were standardized to μg mL-1 for a better view of comparison. This systematic review also identified that cytotoxicity potency was inversely proportional to nanoparticle size. The PLGA nanoparticles predominantly exhibited a size of less than 300 nm and absolute zeta potential ∼20 mV. In conclusion, more comprehensive and critical appraisals of pharmacokinetic, pharmacokinetic, toxicokinetic, in vivo and in vitro tests are required for the investigation of the full value of targeting PLGA nanoparticles for cancer treatment.

Drug Delivery Nanosystems in Glioblastoma Multiforme Treatment: Current State of the Art

Glioblastoma multiforme (GBM) is the most common primary malignant Central Nervous System cancer, responsible for about 4% of all deaths associated with neoplasia, characterized as one of the fatal human cancers. Tumor resection does not possess curative character, thereby radio and/or chemotherapy are often necessary for the treatment of GBM. However, drugs used in GBM chemotherapy present some limitations, such as side effects associated with non-specific drug biodistribution as well as limited bioavailability, which limits their clinical use. To attenuate the systemic toxicity and overcome the poor bioavailability, a very attractive approach is drug encapsulation in drug delivery nanosystems. The main focus of this review is to explore the actual cancer global problem, enunciate barriers to overcome in the pharmacological treatment of GBM, as well as the most updated drug delivery nanosystems for GBM treatment and how they influence biopharmaceutical properties of anti-GBM drugs. The discussion will approach lipid-based and polymeric nanosystems, as well as inorganic nanoparticles, regarding their technical aspects as well as biological effects in GBM treatment. Furthermore, the current state of the art, challenges to overcome and future perspectives in GBM treatment will be discussed.

Citric acid coated ultrasmall superparamagnetic iron oxide nanoparticles conjugated with lactoferrin for targeted negative MR imaging of glioma

The proposed study was to develop the preparation of ultrasmall superparamagnetic iron oxide nanoparticles (USPIONs) modified with citric acid, with surface conjugated with lactoferrin (Lf), which used as a potential targeted contrast agent for magnetic resonance imaging (MRI) of brain glioma. USPIONs were prepared by the thermal decomposition method. The hydrophobic USPIONs were coated with citric acid by the ligand exchange method. Then, Lf was conjugated into the surface of USPIONs. The obtained Lf-USPIONs were analyzed by fourier transform infrared (FTIR) spectroscopy and polyacrylamide gel electrophoresis. The size, size distribution, shape and superparamagnetic property of Lf-USPIONs were investigated with TEM and vibrating sample magnetometer (VSM). Both FTIR and electrophoresis analysis demonstrated the successful conjugation of Lf to the surface of USPIONs. The average size of Lf-USPIONs was about 8.4 ± 0.5 nm, which was determined using the statistics of measured over 100 nanoparticles in the TEM image, with a negative charge of -7.3 ± 0.2 mV. TEM imaging revealed that Lf-USPIONs were good in dispersion and polygonal in morphology. VSM results indicated that Lf-USPIONs were superparamagnetic and the saturated magnetic intensity was about 69.8 emu/g. The Lf-USPIONs also showed good biocompatibility in hemolysis, cytotoxicity, cell migration and blood biochemistry studies. MR imaging results in vitro and in vivo indicated that Lf-USPIONs exhibited good negative contrast enhancement. Taken together, Lf-USPIONs hold great potential for brain gliomas MR imaging as a nanosized targeted contrast agent.

Lactoferrin coated or conjugated nanomaterials as an active targeting approach in nanomedicine

A successful drug delivery to a specific site relies on two essential factors including; efficient entrapment of the drug within the carrier and successful delivery of drug- loaded nanocarrier to the target site without opsonisation or drug release in the circulation before reaching the organ of interest. Lactoferrin (LF) is a glycoprotein belonging to the transferrin (TF) family which can bind to TF receptors (TFRs) and LF membrane internalization receptors (LFRs) highly expressed on the cell surface of both highly proliferating cancer cells and blood brain barrier (BBB), which in turn can facilitate its accessibility to the cell nucleus. This merit could be exploited to develop actively targeted drug delivery systems that can easily cross the BBB or internalize into tumor cells. In this review, the most recent advances of utilizing LF as an active targeting ligand for different types of nanocarriers including: inorganic nanoparticles, dendrimers, synthetic biodegradable polymers, lipid nanocarriers, natural polymers, and nanoemulstions will be highlighted. Collectively, LF seems to be a promising targeting ligand in the field of nanomedicine.

Etoposide Loaded SPION-PNIPAM Nanoparticles Improve the in vitro Therapeutic Outcome on Metastatic Prostate Cancer Cells via Enhanced Apoptosis

Prostate cancer is among the leading causes of death worldwide because its metastatic form is a deadly disease. Therefore, the development of new chemotherapeutics is of immense importance. Nanoparticle technology seems to provide diverse options in this regard. Therefore, poly(N-isopropylacrylamide) (PNIPAM) coated superparamagnetic iron oxide nanoparticles (SPION) loaded with Etoposide were prepared in small sizes (57 nm) and with 3.5 % drug content to improve the efficiency of Etoposide in prostate cancer therapy. Sustained release of the drug was achieved, which found to be sensitive to low pH and high temperature. The anti-growth activity of SPION-PNIPAM-Etoposide formulation against metastatic prostate cancer cells (PC-3, LNCaP) were investigated by SRB assay, then, confirmed by ATP assay. Mode of cell death was evaluated by using flow cytometry analyses. A significant improvement of nanoformulated drug was observed at 5-10 μg/ml doses of the drug in both cell lines. More importantly, this formulation enhanced the cytotoxic effect of Etoposide on PC-3 cells, which is considered more resistant to Etoposide than LNCaP and reduced the IC₅₀ value by 55 % reaching to 4.5 μg drug/ml, which is a very significant improvement in the literature. It was clearly shown that nanoformulated drug provided about 3-fold increases in caspase-dependent early apoptotic cells in PC-3 cells. The novel formulation seems to successfully cause cell death of especially PC-3 metastatic prostate cancer cells. It should therefore be taken into consideration for further animal studies as a novel potent anticancer agent.

Etoposide and olaparib polymer-coated nanoparticles within a bioadhesive sprayable hydrogel for post-surgical localised delivery to brain tumours

Glioblastoma is a malignant brain tumour with a median survival of 14.6 months from diagnosis. Despite maximal surgical resection and concurrent chemoradiotherapy, reoccurrence is inevitable. To try combating the disease at a stage of low residual tumour burden immediately post-surgery, we propose a localised drug delivery system comprising of a spray device, bioadhesive hydrogel (pectin) and drug nanocrystals coated with polylactic acid-polyethylene glycol (NCPPs), to be administered directly into brain parenchyma adjacent to the surgical cavity. We have repurposed pectin for use within the brain, showing in vitro and in vivo biocompatibility, bio-adhesion to mammalian brain and gelling at physiological brain calcium concentrations. Etoposide and olaparib NCPPs with high drug loading have shown in vitro stability and drug release over 120 h. Pluronic F127 stabilised NCPPs to ensure successful spraying, as determined by dynamic light scattering and transmission electron microscopy. Successful delivery of Cy5-labelled NCPPs was demonstrated in a large ex vivo mammalian brain, with NCPP present in the tissue surrounding the resection cavity. Our data collectively demonstrates the pre-clinical development of a novel localised delivery device based on a sprayable hydrogel containing therapeutic NCPPs, amenable for translation to intracranial surgical resection models for the treatment of malignant brain tumours.

Lactoferrin, a multi-functional glycoprotein: Active therapeutic, drug nanocarrier & targeting ligand

Recent progress in protein-based nanomedicine, inspired by the success of Abraxane® albumin-paclitaxel nanoparticles, have resulted in novel therapeutics used for treatment of challenging diseases like cancer and viral infections. However, absence of specific drug targeting, poor pharmacokinetics, premature drug release, and off-target toxicity are still formidable challenges in the clinic. Therefore, alternative protein-based nanomedicines were developed to overcome those challenges. In this regard, lactoferrin (Lf), a glycoprotein of transferrin family, offers a promising biodegradable well tolerated material that could be exploited both as an active therapeutic and drug nanocarrier. This review highlights the major pharmacological actions of Lf including anti-cancer, antiviral, and immunomodulatory actions. Delivery technologies of Lf to improve its pries and enhance its efficacy were also reviewed. Moreover, different nano-engineering strategies used for fabrication of drug-loaded Lf nanocarriers were discussed. In addition, the use of Lf for functionalization of drug nanocarriers with emphasis on tumor-targeted drug delivery was illustrated. Besides its wide application in oncology nano-therapeutics, we discussed the recent advances of Lf-based nanocarriers as efficient platforms for delivery of anti-parkinsonian, anti-Alzheimer, anti-viral drugs, immunomodulatory and bone engineering applications.

Targeting cancer with lactoferrin nanoparticles: recent advances

Lactoferrin, an iron storage protein, is known for its microbicidal activity and its ability to modulate the immune system, mediated through specific interactions with receptors on cell surfaces for internalization. These activities confer a significant versatility to lactoferrin, presenting it as a targeting ligand to disease-bearing cells. Early efforts in developing targeted delivery systems have focused on nano- and microcomposites comprised of metal and polymeric materials. These can be targeted through conjugation or adsorption of lactoferrin to achieve recognition to receptor-expressing cells. More recently, efforts are underway to utilize lactoferrin itself as a medium in loading the therapeutic agent. The functional efficiency of drug-loaded lactoferrin nanoparticles has been evaluated in different disease conditions such as cancer, HIV, Parkinson's disease, etc. This review will present the details of composition and performance of various delivery systems designed and developed using lactoferrin as targeting agent for the treatment of cancer.

Lactoferrin's Anti-Cancer Properties: Safety, Selectivity, and Wide Range of Action

Despite recent advances in cancer therapy, current treatments, including radiotherapy, chemotherapy, and immunotherapy, although beneficial, present attendant side effects and long-term sequelae, usually more or less affecting quality of life of the patients. Indeed, except for most of the immunotherapeutic agents, the complete lack of selectivity between normal and cancer cells for radio- and chemotherapy can make them potential antagonists of the host anti-cancer self-defense over time. Recently, the use of nutraceuticals as natural compounds corroborating anti-cancer standard therapy is emerging as a promising tool for their relative abundance, bioavailability, safety, low-cost effectiveness, and immuno-compatibility with the host. In this review, we outlined the anti-cancer properties of Lactoferrin (Lf), an iron-binding glycoprotein of the innate immune defense. Lf shows high bioavailability after oral administration, high selectivity toward cancer cells, and a wide range of molecular targets controlling tumor proliferation, survival, migration, invasion, and metastasization. Of note, Lf is able to promote or inhibit cell proliferation and migration depending on whether it acts upon normal or cancerous cells, respectively. Importantly, Lf administration is highly tolerated and does not present significant adverse effects. Moreover, Lf can prevent development or inhibit cancer growth by boosting adaptive immune response. Finally, Lf was recently found to be an ideal carrier for chemotherapeutics, even for the treatment of brain tumors due to its ability to cross the blood-brain barrier, thus globally appearing as a promising tool for cancer prevention and treatment, especially in combination therapies.

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.

Native and iron-saturated bovine lactoferrin differently hinder migration in a model of human glioblastoma by reverting epithelial-to-mesenchymal transition-like process and inhibiting interleukin-6/STAT3 axis

Glioblastoma, the most lethal form of brain cancer, is characterized by fast growth, migration and invasion of the surrounding parenchyma, with epithelial-to-mesenchymal transition (EMT)-like process being mostly responsible for tumour spreading and dissemination. A number of actors, including cadherins, vimentin, transcriptional factors such as SNAIL, play critical roles in the EMT process. The interleukin (IL)-6/STAT3 axis has been related to enhanced glioblastoma's migration and invasion abilities as well. Here, we present data on the differential effects of native and iron-saturated bovine lactoferrin (bLf), an iron-chelating glycoprotein of the innate immune response, in inhibiting migration in a human glioblastoma cell line. Through a wound healing assay, we found that bLf was able to partially or completely hinder cell migration, depending on its iron saturation rate. At a molecular level, bLf down-regulated both SNAIL and vimentin expression, while inducing a notable increase in cadherins' levels and inhibiting IL-6/STAT3 axis. Again, these effects positively correlated to bLf iron-saturation state, with the Holo-form resulting more efficient than the native one. Overall, our data suggest that bLf could represent a novel and efficient adjuvant treatment for glioblastoma's standard therapeutic approaches.

Folate-conjugated nanovehicles: Strategies for cancer therapy

Cancer theranostics represents a strategy that aims at combining diagnosis with therapy through the simultaneous imaging and targeted delivery of therapeutics to cancer cells. Recently, the folate receptor alpha has emerged as an attractive theranostic target due to its overexpression in multiple solid tumors and its great functional versatility. In fact, it can be incorporated into folate-conjugated nano-systems for imaging and drug delivery. Hence, it can be used along the line of personalized clinical strategies as both an imaging tool and a delivery method ensuring the selective transport of treatments to tumor cells, thus highlighting its theranostic qualities. In this review, we will explore these theranostic characteristics in detail and assess their clinical potential. We will also discuss the technological advances that have allowed the design of sophisticated folate-based nanocarriers harboring various chemical properties and suited for the transport of various therapeutic agents.

Folic acid functionalized nanoparticles as pharmaceutical carriers in drug delivery systems

Conventional chemotherapeutic approaches in cancer therapy such as surgery, chemotherapy, and radiotherapy have several disadvantages due to their nontargeted distributions in the whole body. On the other hand, nanoparticles (NPs) based therapies are remarkably progressing to solve several limitations of conventional drug delivery systems (DDSs) including nonspecific biodistribution and targeting, poor water solubility, weak bioavailability and biodegradability, low pharmacokinetic properties, and so forth. The enhanced permeability and retention effect escape from P-glycoprotein trap in cancer cells as a passive targeting mechanism, and active targeting strategies are also other most important advantages of NPs in cancer diagnosis and therapy. Folic acid (FA) is one of the biologic molecules which has been targeted overexpressed-folic acid receptor (FR) on the surface of cancer cells. Therefore, conjugation of FA to NPs most easily enhances the FR-mediated targeting delivery of therapeutic agents. Here, the recent works in FA which have been decorated NPs-based DDSs are discussed and cancer therapy potency of these NPs in clinical trials are presented.

Dual-selective photodynamic therapy with a mitochondria-targeted photosensitizer and fiber optic cannula for malignant brain tumors

Among brain tumors, glioblastoma multiforme (GBM) is the most common and aggressive form (WHO grade IV) with a median survival of only 14.6 months in adults. Photodynamic therapy (PDT) is a combination of a photosensitizer (PS), light and molecular oxygen, and considered a promising treatment for GBM. Therapeutic outcomes of PDT rely on ROS generation in a tumor microenvironment, which can be controlled with dual selectivity by localization of the photosensitizer and confinement of light to the targeted tumor microenvironment. We previously demonstrated the photodynamic anticancer efficacy of mitochondrial-targeted photosensitizer-loaded albumin nanoparticles (PS@chol-BSA NPs). In this study, the photodynamic therapeutic effect of PS@chol-BSA NPs was further enhanced by confinement of light using a fiber optic cannula in orthotopic GBM-xenografted mice. In vitro cellular uptake and phototoxicity of PS@chol-BSA NPs were evaluated in brain tumor (U87MG) and endothelial (bEnd.3) cells. In vivo biodistribution was determined by an in vivo imaging system (IVIS) and the photodynamic efficacy was evaluated with confined laser irradiation. PS@chol-BSA NPs showed higher cellular uptake and phototoxicity in U87MG cells than in bEnd.3 cells. PS@chol-BSA NPs showed a brain tumor accumulation of 0.2%ID within 2 h and remain in the brain tumor for 22 h. When compared to the control group, there was remarkable suppression in tumor growth by laser irradiation with and without the fiber optic cannula at a dose of 1 mg kg^-1, in which significant tumor suppression up to 40% was observed with confined laser irradiation. Together, dual-selective photodynamic therapy with a mitochondria-targeted photosensitizer and fiber optic cannula provides a promising therapeutic strategy for malignant brain tumors.

Protection against Neurodegeneration in the Hippocampus Using Sialic Acid- and 5-HT-Moduline-Conjugated Lipopolymer Nanoparticles

Significant involvement of oxidative stress in the brain can develop Alzheimer's disease (AD); however, a great number of clinical trials explains the limited success of antioxidant therapy in dealing with this neurodegenerative disease. Here, we established a lipopolymer system of poly(lactide-co-glycolide) (PLGA) nanoparticles (NPs) incorporated with phosphatidic acid (PA) and modified with sialic acid (SA) and 5-hydroxytryptamine-moduline (5HTM) to improve quercetin (QU) activity against oxidative stress induced by amyloid-β (Aβ) deposits. Morphological studies revealed a uniform exterior of QU-SA-5HTM-PA-PLGA NPs with a spherical structure and enhanced aggregation with inclusion of PA in the formulation. A better brain-targeted delivery of the lipopolymeric NPs was verified from the high blood-brain barrier (BBB) permeability of QU through strong interactions of surface SA and 5HTM with O-linked N-acetylglucosamine and 5-HT1B receptors, respectively. Immunofluorescence staining images also supported QU-SA-5HTM-PA-PLGA NPs to traverse the microvessels of AD rat brain. Western blot analysis showed that QU-loaded PA-PLGA NPs suppressed caspase-3 expression. The ability of the nanocarriers to recognize Aβ fibrils was demonstrated from the reduced senile plaque formation and the attenuated acetylcholinesterase and malondialdehyde activity in the hippocampus. Hence, the medication of QU-SA-5HTM-PA-PLGA NPs can facilitate the BBB penetration and prevent Aβ accumulation, lipid peroxidation, and neuronal apoptosis for the AD management.

Targeted delivery of etoposide, carmustine and doxorubicin to human glioblastoma cells using methoxy poly(ethylene glycol)‑poly(ε‑caprolactone) nanoparticles conjugated with wheat germ agglutinin and folic acid

Wheat germ agglutinin (WGA) and folic acid (FA)-grafted methoxy poly(ethylene glycol) (MPEG)‑poly(ε‑caprolactone) (PCL) nanoparticles (WFNPs) were applied to transport anticancer drugs across the blood-brain barrier and treat glioblastoma multiforme (GBM). PCL was copolymerized with MPEG, and MPEG-PCL NPs were stabilized with pluronic F127 using a microemulsion-solvent evaporation technique and crosslinked with WGA and FA. The targeting ability of WFNPs loaded with etoposide (ETO), carmustine (BCNU) and doxorubicin (DOX) was investigated via the binding affinity of drug-loaded NP formulations to N‑acetylglucosamine expressed in human brain microvascular endothelial cells and to folate receptor in malignant U87MG cells. We found that a shorter PCL chain in drug-loaded MPEG-PCL NPs yielded a smaller average size of the particles. An increase in PCL chain length (stronger hydrophobicity) enhanced drug entrapment efficiencies in MPEG-PCL NPs, and reduced drug-releasing rates from NP formulations. In addition, anti-proliferative activity against U87MG cells for the 3 drugs followed the order of WFNPs > FA-grafted NPs > WGA-grafted NPs > MPEG-PCL NPs. Immunofluorescence staining revealed that the ligands of drug-loaded WFNPs connected to N‑acetylglucosamine and folate receptor with the help of surface WGA and FA. WFNPs carrying ETO, BCNU and DOX acted as dual-targeting nanocarriers, and their use can be a promising approach to inhibiting GBM growth in the brain.

pH-sensitive folic acid and dNP2 peptide dual-modified liposome for enhanced targeted chemotherapy of glioma

Effective chemotherapy for clinical glioma treatment is still lacking due to the poor penetration of blood-brain barrier (BBB) and the poor internalization into tumor cells. To facilitate the transmigration across the BBB as well as the glioma targeting of chemotherapeutics, we constructed cell penetrating peptide dNP2 and tumor microenvironment-cleavable folic acid (FA) dual modified, paclitaxel (PTX) loaded liposome for the targeted delivery of glioma. The modification of dNP2 significantly enhanced the transmigration across the BBB in an in vitro BBB model. The acid-cleavable cFd-Lip/PTX exhibited sensitive cleavage of FA at pH 6.8, which led to enhanced cellular uptake mediated by both cell penetrating peptide dNP2 and the interaction between FA and folate receptor (FR) on the glioma cells. After intravenous injection, compared with non-cleavable Fd-Lip and single modified liposomes, cFd-Lip enhanced the accumulation in orthotropic glioma and improved the anti-tumor effect of glioma-bearing mice. The dual modified liposomes also facilitated deep penetration into tumor cells and consequently enhanced the cytotoxicity of PTX-loaded liposomes. The acid-cleavable dual modified strategy retained the BBB penetrating and tumor targeting ability, meanwhile, the cleavage of FA further maximized the cell permeability of dNP2, exhibiting enhanced tumor targeting effect. The multi-targeting strategy provides a promising approach towards targeted chemotherapy for glioma.

Etoposide loaded layered double hydroxide nanoparticles reversing chemoresistance and eradicating human glioma stem cells in vitro and in vivo

Glioblastoma (GBM) is the most malignant and lethal glioma in human brain tumors and contains self-renewing, tumorigenic glioma stem cells (GSCs) that contribute to tumor initiation, therapeutic resistance and further recurrence. In this study, we combined in vitro cellular efficacy with in vivo antitumor performance to evaluate the outcome of an etoposide (VP16) loaded layered double hydroxide (LDH) nanocomposite (L-V) on human GSCs. The effects on GSC proliferation and apoptosis showed that loading with LDH could significantly sensitize GSCs to VP16 and enhance the GSC elimination. Further qPCR and western blot assays demonstrated that L-V could effectively attenuate GSC related pluripotency gene expression and reduce the cancer stemness. An in vivo GSC xenograft mice model showed that L-V can overcome drug resistance, eradicate GSCs, sharply decrease the stemness and reverse the epithelial-mesenchymal transition (EMT). RNA-seq analysis elucidated that L-V plays a vital role by down-regulating the PI3K/AKt/mTOR expression and activating the Wnt/GSK3β/β-catenin signaling pathway, hence leading to GSC stemness loss and greatly enhancing the GSC targeting effect. Taken together, this study demonstrated the outstanding performance of L-V reversing the drug resistance of GSCs, thus providing a novel strategy for clinical translation application of nanomedicine in malignant glioma chemotherapy.

Peptide and protein nanoparticle conjugates: versatile platforms for biomedical applications

Peptide- and protein-nanoparticle conjugates have emerged as powerful tools for biomedical applications, enabling the treatment, diagnosis, and prevention of disease. In this review, we focus on the key roles played by peptides and proteins in improving, controlling, and defining the performance of nanotechnologies. Within this framework, we provide a comprehensive overview of the key sequences and structures utilised to provide biological and physical stability to nano-constructs, direct particles to their target and influence their cellular and tissue distribution, induce and control biological responses, and form polypeptide self-assembled nanoparticles. In doing so, we highlight the great advances made by the field, as well as the challenges still faced in achieving the clinical translation of peptide- and protein-functionalised nano-drug delivery vehicles, imaging species, and active therapeutics.