Development of Nanoparticles for Drug Delivery to Brain Tumor: The Effect of Surface Materials on Penetration Into Brain Tissue

Effect of sub-acute exposure of metal-organic framework-199 on cognitive function and oxidative stress level of brain tissue in rat

Metal-Organic Framework-199 (MOF-199) is a subgroup of MOFs that is utilized in different medical fields such as drug delivery. In the current study, the effect of sub-acute exposure to MOF-199 on spatial memory, working memory, inflammatory mediators' expression, and oxidative stress level of brain tissue has been investigated. Thirty-two male Wistar rats were randomly divided into four groups as vehicle, MOF-199 at doses 0.3, 3, or 6 mg/kg. After four injections of relevant interventions via tail vein during 14 days, behavioral parameters were investigated using Y-maze and Morris Water Maze (MWM) tests. Oxidative stress was measured by ferric reducing antioxidant power (FRAP) and thiobarbituric acid-reacting substance (TBARS) tests. The expression levels of TNF-α and IL-1β were assessed by quantitative real-time reverse-transcription PCR (qRT-PCR). No significant differences were observed in working memory, spatial learning and memory of MOF-199 receiving rats. Additionally, the level of oxidative stress and inflammatory genes expression were not remarkably changed in the brain tissues of MOF-199 treated rats. Despite the lack of remarkable toxic effects of sub-acute exposure to MOF-199, more studies with a longer duration of administration are necessary to use this substance for drug delivery systems in diseases related to the nervous system.

To see or not to see: In vivo nanocarrier detection methods in the brain and their challenges

Nanoparticles have a great potential to significantly improve the delivery of therapeutics to the brain and may also be equipped with properties to investigate brain function. The brain, being a highly complex organ shielded by selective barriers, requires its own specialized detection system. However, a significant hurdle to achieve these goals is still the identification of individual nanoparticles within the brain with sufficient cellular, subcellular, and temporal resolution. This review aims to provide a comprehensive summary of the current knowledge on detection systems for tracking nanoparticles across the blood-brain barrier and within the brain. We discuss commonly employed in vivo and ex vivo nanoparticle identification and quantification methods, as well as various imaging modalities able to detect nanoparticles in the brain. Advantages and weaknesses of these modalities as well as the biological factors that must be considered when interpreting results obtained through nanotechnologies are summarized. Finally, we critically evaluate the prevailing limitations of existing technologies and explore potential solutions.

Rational Design of Pectin-Chitosan Polyelectrolyte Nanoparticles for Enhanced Temozolomide Delivery in Brain Tumor Therapy

Conventional chemotherapeutic approaches currently used for brain tumor treatment have low efficiency in targeted drug delivery and often have non-target toxicity. Development of stable and effective drug delivery vehicles for the most incurable diseases is one of the urgent biomedical challenges. We have developed polymer nanoparticles (NPs) with improved temozolomide (TMZ) delivery for promising brain tumor therapy, performing a rational design of polyelectrolyte complexes of oppositely charged polysaccharides of cationic chitosan and anionic pectin. The NPs' diameter (30 to 330 nm) and zeta-potential (-29 to 73 mV) varied according to the initial mass ratios of the biopolymers. The evaluation of nanomechanical parameters of native NPs demonstrated changes in Young's modulus from 58 to 234 kPa and adhesion from -0.3 to -3.57 pN. Possible mechanisms of NPs' formation preliminary based on ionic interactions between ionogenic functional groups were proposed by IR spectroscopy and dynamic rheology. The study of the parameters and kinetics of TMZ sorption made it possible to identify compounds that most effectively immobilize and release the active substance in model liquids that simulate the internal environment of the body. A polyelectrolyte carrier based on an equal ratio of pectin-chitosan (0.1% by weight) was selected as the most effective for the delivery of TMZ among a series of obtained NPs, which indicates a promising approach to the treatment of brain tumors.

Overcoming brain barriers through surface-functionalized liposomes for glioblastoma therapy; current status, challenges and future perspective

Glioblastoma (GB) originating from astrocytes is considered a grade IV astrocytoma tumor with severe consequences. The blood-brain barrier (BBB) offers a major obstacle in drug delivery to the brain to overcome GB. The current treatment options possess limited efficacy and maximal systemic toxic effects in GB therapy. Emerging techniques such as targeted drug delivery offer significant advantages, including enhanced drug delivery to the tumor site by overcoming the BBB. This review article focuses on the status of surface-modified lipid nanocarriers with functional ligands to efficiently traverse the BBB and improve brain targeting for successful GB treatment. The difficulties with surface-functionalized liposomes and potential future directions for opening up novel treatment options for GB are highlighted.

Progress and Challenges in the Diagnosis and Treatment of Brain Cancer Using Nanotechnology

Primary brain cancer or brain cancer is the overgrowth of abnormal or malignant cells in the brain or its nearby tissues that form unwanted masses called brain tumors. People with malignant brain tumors suffer a lot, and the expected life span of the patients after diagnosis is often only around 14 months, even with the most vigorous therapies. The blood-brain barrier (BBB) is the main barrier in the body that restricts the entry of potential chemotherapeutic agents into the brain. The chances of treatment failure or low therapeutic effects are some significant drawbacks of conventional treatment methods. However, recent advancements in nanotechnology have generated hope in cancer treatment. Nanotechnology has shown a vital role starting from the early detection, diagnosis, and treatment of cancer. These tiny nanomaterials have great potential to deliver drugs across the BBB. Beyond just drug delivery, nanomaterials can be simulated to generate fluorescence to detect tumors. The current Review discusses in detail the challenges of brain cancer treatment and the application of nanotechnology to overcome those challenges. The success of chemotherapeutic treatment or the surgical removal of tumors requires proper imaging. Nanomaterials can provide imaging and therapeutic benefits for cancer. The application of nanomaterials in the diagnosis and treatment of brain cancer is discussed in detail by reviewing past studies.

Mathematical modelling of microneedle-mediated transdermal delivery of drug nanocarriers into skin tissue and circulatory system

Microneedle-mediated transdermal delivery using nanocarriers can successfully overcome the barrier of the stratum corneum and protect drugs from elimination in skin tissues. However, the effectiveness of drug delivery to different layers of skin tissues and the circulatory system varies considerably, subject to the properties of the drug delivery system and delivery regime. How to maximise delivery outcomes remains unclear. In this study, mathematical modelling is employed to investigate this transdermal delivery under various conditions, using the skin model that is reconstructed based on the realistic skin anatomical structure. Treatment efficacy is evaluated in terms of drug exposure over time. The modelling results demonstrate the complex dependence of drug accumulation and distribution on the nanocarrier properties, microneedle properties and environment in different skin layers and blood. Specifically, delivery outcomes in the entire skin and blood can be improved by increasing the loading dose and reducing microneedle spacing. However, several parameters need to be optimised with respect to the specific location of the target site in the tissue for better treatment; these include the drug release rate, nanocarrier diffusivity in microneedle and skin tissue, nanocarrier transvascular permeability, nanocarrier partition coefficient between tissue and microneedle, microneedle length, wind speed and relative humidity. The delivery is less sensitive to the diffusivity and physical degradation rate of free drugs in microneedle, and their partition coefficient between tissue and microneedle. Results obtained from this study can be used to improve the design of the microneedle-nanocarrier combined drug delivery system and delivery regime.

Polymer nanocarriers for targeted local delivery of agents in treating brain tumors

Glioblastoma (GBM), the deadliest brain cancer, presents a multitude of challenges to the development of new therapies. The standard of care has only changed marginally in the past 17 years, and few new chemotherapies have emerged to supplant or effectively combine with temozolomide. Concurrently, new technologies and techniques are being investigated to overcome the pharmacokinetic challenges associated with brain delivery, such as the blood brain barrier (BBB), tissue penetration, diffusion, and clearance in order to allow for potent agents to successful engage in tumor killing. Alternative delivery modalities such as focused ultrasound and convection enhanced delivery allow for the local disruption of the BBB, and the latter in particular has shown promise in achieving broad distribution of agents in the brain. Furthermore, the development of polymeric nanocarriers to encapsulate a variety of cargo, including small molecules, proteins, and nucleic acids, have allowed for formulations that protect and control the release of said cargo to extend its half-life. The combination of local delivery and nanocarriers presents an exciting opportunity to address the limitations of current chemotherapies for GBM toward the goal of improving safety and efficacy of treatment. However, much work remains to establish standard criteria for selection and implementation of these modalities before they can be widely implemented in the clinic. Ultimately, engineering principles and nanotechnology have opened the door to a new wave of research that may soon advance the stagnant state of GBM treatment development.

Overcoming the blood–brain barrier for the therapy of malignant brain tumor: current status and prospects of drug delivery approaches

Besides the broad development of nanotechnological approaches for cancer diagnosis and therapy, currently, there is no significant progress in the treatment of different types of brain tumors. Therapeutic molecules crossing the blood–brain barrier (BBB) and reaching an appropriate targeting ability remain the key challenges. Many invasive and non-invasive methods, and various types of nanocarriers and their hybrids have been widely explored for brain tumor treatment. However, unfortunately, no crucial clinical translations were observed to date. In particular, chemotherapy and surgery remain the main methods for the therapy of brain tumors. Exploring the mechanisms of the BBB penetration in detail and investigating advanced drug delivery platforms are the key factors that could bring us closer to understanding the development of effective therapy against brain tumors. In this review, we discuss the most relevant aspects of the BBB penetration mechanisms, observing both invasive and non-invasive methods of drug delivery. We also review the recent progress in the development of functional drug delivery platforms, from viruses to cell-based vehicles, for brain tumor therapy. The destructive potential of chemotherapeutic drugs delivered to the brain tumor is also considered. This review then summarizes the existing challenges and future prospects in the use of drug delivery platforms for the treatment of brain tumors.

Efficacy of Polymer-Based Nanomedicine for the Treatment of Brain Cancer

Malignant brain tumor is a life-threatening disease with a low survival rate. The therapies available for the treatment of brain tumor is limited by poor uptake via the blood-brain barrier. The challenges with the chemotherapeutics used for the treatment of brain tumors are poor distribution, drug toxicity, and their inability to pass via the blood-brain barrier, etc. Several researchers have investigated the potential of nanomedicines for the treatment of brain cancer. Nanomedicines are designed with nanosize particle sizes with a large surface area and are loaded with bioactive agents via encapsulation, immersion, conjugation, etc. Some nanomedicines have been approved for clinical use. The most crucial part of nanomedicine is that they promote drug delivery across the blood-brain barrier, display excellent specificity, reduce drug toxicity, enhance drug bioavailability, and promote targeted drug release mechanisms. The aforementioned features make them promising therapeutics for brain targeting. This review reports the in vitro and in vivo results of nanomedicines designed for the treatment of brain cancers.

Mathematical modelling of nanoparticle-mediated topical drug delivery to skin tissue

Nanoparticles have been extensively studied to improve drug delivery outcomes, however, their use in topical delivery remains controversial. Although the feasibility to cross the human skin barrier has been demonstrated in experiments, the risk of low drug concentration in deep tissue still limits the application. In this study, mathematical modelling is employed to examine the performance of nanoparticle-mediated topical delivery for sending drugs into the deep skin tissue. The pharmacokinetic effect is evaluated based on the drug exposure over time. As compared to the delivery using plain drugs, nanoparticle-mediated topical delivery has the potential to significantly improve the drug exposure in deep skin tissue. Modelling predictions denote that the importance of sufficient long-term drug-skin contact in achieving effective drug deposition in the deep skin tissue. The delivery outcomes are highly sensitive to the release rate. Accelerating the release from nanoparticles in stratum corneum is able to improve the drug exposure in stratum corneum and viable epidermis while resulting in the reductions in dermis and blood. The release rate in stratum corneum and viable epidermis should be well-designed below a threshold for generating effective drug accumulation in dermis and blood. A more localised drug accumulation can be achieved in the capillary-rich region of dermis by increasing the local release rate. The release rate in dermis needs to be optimised to increase the drug exposure in the dermis region where there are fewer blood and lymphatics capillaries. Results from this study can be used to improve the regimen of topical delivery for localised treatment.

A Critical Review of the Use of Surfactant-Coated Nanoparticles in Nanomedicine and Food Nanotechnology

Surfactants, whose existence has been recognized as early as 2800 BC, have had a long history with the development of human civilization. With the rapid development of nanotechnology in the latter half of the 20th century, breakthroughs in nanomedicine and food nanotechnology using nanoparticles have been remarkable, and new applications have been developed. The technology of surfactant-coated nanoparticles, which provides new functions to nanoparticles for use in the fields of nanomedicine and food nanotechnology, is attracting a lot of attention in the fields of basic research and industry. This review systematically describes these "surfactant-coated nanoparticles" through various sections in order: 1) surfactants, 2) surfactant-coated nanoparticles, application of surfactant-coated nanoparticles to 3) nanomedicine, and 4) food nanotechnology. Furthermore, current progress and problems of the technology using surfactant-coated nanoparticles through recent research reports have been discussed.

Progress in the study of D-α-tocopherol polyethylene glycol 1000 succinate (TPGS) reversing multidrug resistance

Currently, multidrug resistance (MDR) is one of the major reasons for failure in clinical cancer chemotherapy. Overexpression of the ATP binding cassette (ABC) transporter P-glycoprotein (P-gp), which significantly increases the efflux of anticancer drugs from tumor cells, enhances MDR. In the past few decades, four generations of P-gp inhibitors have appeared. However, they are limited in clinical application due to their severe toxic side effects. As a P-gp inhibitor and carrier for loading chemotherapy agents, TPGS has received increasing attention due to its advantages and unique properties of reversing MDR. TPGS is an amphipathic agent that increases the solubility of most chemotherapy drugs and decreases severe side effects. In addition, TPGS is an excellent carrier with P-gp-inhibiting ability. In this review, we summarize the latest articles on TPGS-based nanodelivery systems to prevent MDR.

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.

Nanotechnology and Nanocarrier-Based Drug Delivery as the Potential Therapeutic Strategy for Glioblastoma Multiforme: An Update

Simple Summary

Glioblastoma multiforme (GBM) are among the most lethal tumors. The highly invasive nature and presence of GBM stem cells, as well as the blood brain barrier (BBB) which limits chemotherapeutic drugs from entering the tumor mass, account for the high chance of treatment failure. Recent developments have found that nanoparticles can be conjugated to liposomes, dendrimers, metal irons, or polymeric micelles, which enhance the drug-loaded compounds to efficiently penetrate the BBB, thus offering new possibilities for overcoming GBM stem cell-mediated resistance to chemotherapy and radiation therapy. In addition, there have been new emerging strategies that use nanocarriers for successful GBM treatment in animal models. This review highlights the recent development of nanotechnology and nanocarrier-based drug delivery for treatment of GBMs, which may be a promising therapeutic strategy for this tumor entity.

Abstract

Glioblastoma multiforme (GBM) is the most common and malignant brain tumor with poor prognosis. The heterogeneous and aggressive nature of GBMs increases the difficulty of current standard treatment. The presence of GBM stem cells and the blood brain barrier (BBB) further contribute to the most important compromise of chemotherapy and radiation therapy. Current suggestions to optimize GBM patients’ outcomes favor controlled targeted delivery of chemotherapeutic agents to GBM cells through the BBB using nanoparticles and monoclonal antibodies. Nanotechnology and nanocarrier-based drug delivery have recently gained attention due to the characteristics of biosafety, sustained drug release, increased solubility, and enhanced drug bioactivity and BBB penetrability. In this review, we focused on recently developed nanoparticles and emerging strategies using nanocarriers for the treatment of GBMs. Current studies using nanoparticles or nanocarrier-based drug delivery system for treatment of GBMs in clinical trials, as well as the advantages and limitations, were also reviewed.

Recent Advances on Antitumor Agents-loaded Polymeric and Lipid-based Nanocarriers for the Treatment of Brain Cancer

In 2016, there were 17.2 million cancer cases, which caused 8.9 million deaths worldwide. Of all cancers, ranked by absolute years of life lost, brain and central nervous system cancers were classified in the nine positions between 2006 and 2016. Glioblastoma is the most common malignant primary brain tumor and comprises 80% of malignant tumours. The therapeutic approach usually involves the combination of surgery and radiotherapy, which present a high risk for the patient and are not always effective in the most aggressive cases. Chemotherapy commonly includes a specific number of cycles given over a set period of time, in which patients receive one drug or a combination of different compounds. The difficulty of access for the neurosurgeon to remove the tumor, the limitation of the penetration of the antitumor agents caused by the blood-brain barrier and the serious adverse effects of these drugs significantly compromise the therapeutic success in these patients. To solve these problems and improve the effectiveness of existing treatments, as well as new molecules, the use of nanotechnology is arousing much interest in the last decades in this field. The use of polymeric and lipid-based nanosystems is one of the best alternatives for the central delivery of drugs due to their versatility, easy manufacturing, biocompatibility, biodegradability and drug targeting, among other virtues. Thus, in this review, we will explore the recent advances in the latest anticancer agent's development associated with polymeric and lipid-based nanocarriers as a novel tools for the management of brain tumors.

Cytotoxic lanthanum oxide nanoparticles sensitize glioblastoma cells to radiation therapy and temozolomide: an in vitro rationale for translational studies

Glioblastoma (GBM) is a malignant brain tumour with a dismal prognosis, despite best treatment by surgical resection, radiation therapy (RT) and chemotherapy with temozolomide (TMZ). Nanoparticle (NP) therapy is an emerging consideration due to the ability of NPs to be formulated and cross the blood brain barrier. Lanthanum oxide (La2O3) NPs are therapeutically advantageous due to the unique chemical properties of lanthanum making it cytotoxic to cancers, and able to enhance existing anti-cancer treatments. However, La2O3 NPs have yet to be thoroughly investigated in brain tumors. We show that these NPs can reach the brain after venous injection, penetrate into GBM cells via endocytosis, dissociate to be cytotoxic, and enhance the therapeutic effects of RT and TMZ. The mechanisms of cell death by La2O3 NPs were found to be multifaceted. Increasing NP concentration was correlated to increased intrinsic and extrinsic apoptosis pathway markers in a radical oxygen species (ROS)-dependent manner, as well as involving direct DNA damage and autophagic pathways within GBM patient-derived cell lines. NP interactions to sensitize GBM to RT and TMZ were shown to involve these pathways by enhancing ROS and apoptotic mechanisms. We therefore demonstrate the therapeutic potential of La2O3 NPs to treat GBM cells in vitro, and encourage translational exploration in the future.

Lanthanum nanoparticles to target the brain: proof of biodistribution and biocompatibility with adjuvant therapies

Aim: To determine the biodistribution of lanthanum (III) oxide (La₂O₃) nanoparticle (NP) therapy to the brain and its biocompatibility with radiation therapy (RT) and chemotherapy (CT). Materials & methods: Healthy balb/c nude mice were administered 4 weekly doses of La₂O₃ NP therapy via tail vein injection. Organ weights and lanthanum concentrations were evaluated. Results: La₂O₃ NP penetrated the brain. Concentrations were found to peak in the brain at 24 h after injection and persisted at 8 weeks after injection. Neither RT nor CT affected biodistribution. No adverse events or safety concerns in other organs were noted. Conclusion: La₂O₃ NP can reach the brain to target neurological disease and is biocompatible with RT and CT in a biological system.

Quality by design (QbD) approach in processing polymeric nanoparticles loading anticancer drugs by high pressure homogenizer

Polymeric nanoparticles prepared using high pressure homogenizer (HPH) present some unique challenges during manufacturing which can be better understood by application of quality by design (QbD) approaches. The present review highlights the ways to identify the critical material attributes which includes the anticancer drugs, polymers, surfactants, solvent system and dispersion system. A comprehensive understanding of the critical processing parameters like pressure and number of cycles during the working of HPH used in putting forward the critical quality attributes such as size, shape, surface charge or droplet stabilization. Such QbD approach will involve development of an effective control strategy for would ensure safe encapsulation of anticancer drugs for successful product development. Proper addressing of the issues related to scaling-up would lead to successful commercialization of the nano-sized formulations loaded with anticancer drugs.

Multifunctional Polymeric Nanoplatforms for Brain Diseases Diagnosis, Therapy and Theranostics

The blood-brain barrier (BBB) acts as a barrier to prevent the central nervous system (CNS) from damage by substances that originate from the blood circulation. The BBB limits drug penetration into the brain and is one of the major clinical obstacles to the treatment of CNS diseases. Nanotechnology-based delivery systems have been tested for overcoming this barrier and releasing related drugs into the brain matrix. In this review, nanoparticles (NPs) from simple to developed delivery systems are discussed for the delivery of a drug to the brain. This review particularly focuses on polymeric nanomaterials that have been used for CNS treatment. Polymeric NPs such as polylactide (PLA), poly (D, L-lactide-co-glycolide) (PLGA), poly (ε-caprolactone) (PCL), poly (alkyl cyanoacrylate) (PACA), human serum albumin (HSA), gelatin, and chitosan are discussed in detail.