Insights into Targeted and Stimulus-Responsive Nanocarriers for Brain Cancer Treatment.

Brain cancers, especially glioblastoma multiforme, are associated with poor prognosis due to the limited efficacy of current therapies. Nanomedicine has emerged as a versatile technology to treat various diseases, including cancers, and has played an indispensable role in combatting the COVID-19 pandemic as evidenced by the role that lipid nanocarrier-based vaccines have played. The tunability of nanocarrier physicochemical properties -including size, shape, surface chemistry, and drug release kinetics- has resulted in the development of a wide range of nanocarriers for brain cancer treatment. These nanocarriers can improve the pharmacokinetics of drugs, increase blood-brain barrier transfer efficiency, and specifically target brain cancer cells. These unique features would potentially allow for more efficient treatment of brain cancer with fewer side effects and better therapeutic outcomes. This review provides an overview of brain cancers, current therapeutic options, and challenges to efficient brain cancer treatment. The latest advances in nanomedicine strategies are investigated with an emphasis on targeted and stimulus-responsive nanocarriers and their potential for clinical translation.

Hydrophobic ion pairing and microfluidic nanoprecipitation enable efficient nanoformulation of a small molecule indolamine 2, 3-dioxygenase inhibitor immunotherapeutic.

Blockade of programmed cell death-1 (PD-1) is a transformative immunotherapy. However, only a fraction of patients benefit, and there is a critical need for broad-spectrum checkpoint inhibition approaches that both enhance the recruitment of cytotoxic immune cells in cold tumors and target resistance pathways. Indoleamine 2, 3-dioxygenase (IDO) small molecule inhibitors are promising but suboptimal tumor bioavailability and dose-limiting toxicity have limited therapeutic benefits in clinical trials. This study reports on a nanoformulation of the IDO inhibitor navoximod within polymeric nanoparticles prepared using a high-throughput microfluidic mixing device. Hydrophobic ion pairing addresses the challenging physicochemical properties of navoximod, yielding remarkably high loading (>10%). The nanoformulation efficiently inhibits IDO and, in synergy with PD-1 antibodies improves the anti-cancer cytotoxicity of T-cells, in vitro and in vivo. This study provides new insight into the IDO and PD-1 inhibitors synergy and validates hydrophobic ion pairing as a simple and clinically scalable formulation approach.

Bosutinib high density lipoprotein nanoformulation has potent tumour radiosensitisation effects.

Disruption of the cell cycle is among the most effective approach to increase tumour cells' radio-sensitivity. However, the presence of dose-limiting side effects hampers the clinical use of tyrosine kinase inhibitors targeting the cell cycle. Towards addressing this challenge, we identified a bosutinib nanoformulation within high density lipoprotein nanoparticles (HDL NPs) as a promising radiosensitiser. Bosutinib is a kinase inhibitor clinically approved for the treatment of chronic myeloid leukemia that possesses radiosensitising properties through cell cycle checkpoint inhibition. We found that a remarkably high bosutinib loading (> 10%) within HDL NPs could be reliably achieved under optimal preparation conditions. The radiosensitisation activity of the bosutinib-HDL nanoformulation was first assessed in vitro in UM-SCC-1 head and neck squamous cell carcinoma (HNSCC) cells, which confirmed efficient disruption of the radiation induced G2/M cell cycle arrest. Interestingly, the bosutinib nanoformulation out-performed free bosutinib, likely because of the specific affinity of HDL NPs with tumour cells. The combination of bosutinib-HDL NPs and radiotherapy significantly controlled tumour growth in an immunocompetent murine HNSCC model. The bosutinib-HDL nanoformulation also enhanced the radiation induced immune response through the polarisation of tumour associated macrophages towards proinflammatory phenotypes.

Formulation of simvastatin within high density lipoprotein enables potent tumour radiosensitisation.

Preclinical, clinical and epidemiologic studies have established the potent anticancer and radiosensitisation effects of HMG-CoA reductase inhibitors (statins). However, the low bioavailability of oral statin formulations is a key barrier to achieving effective doses within tumour. To address this issue and ascertain the radiosensitisation potential of simvastatin, we developed a parenteral high density lipoprotein nanoparticle (HDL NP) formulation of this commonly used statin. A scalable method for the preparation of the simvastatin-HDL NPs was developed using a 3D printed microfluidic mixer. This enables the production of litre scale amounts of particles with minimal batch to batch variation. Simvastatin-HDL NPs enhanced the radiobiological response in 2D/3D head and neck squamous cell carcinoma (HNSCC) in vitro models. The simvastatin-HDL NPs radiosensitisation was comparable to that of 10 and 5 times higher doses of free drug in 2D and 3D cultures, respectively, which could be partially explained by more efficient cellular uptake of the statin in the nanoformulation as well as by the inherent biological activity of the HDL NPs on the cholesterol pathway. The radiosensitising potency of the simvastatin-HDL nanoformulation was validated in an immunocompetent MOC-1 HNSCC tumour bearing mouse model. This data supports the rationale of repurposing statins through reformulation within HDL NPs. Statins are safe and readily available molecules including as generic, and their use as radiosensitisers could lead to much needed effective and affordable approaches to improve treatment of solid tumours.

High density lipoprotein nanoparticle as delivery system for radio-sensitising miRNA: An investigation in 2D/3D head and neck cancer models.

Radiotherapy is one of the main treatment options for head and neck cancer patients. However, its clinical efficacy is hindered by both radiation induced side effects and radio-resistance. Radio-sensitising approaches with acceptable toxicity are being actively investigated. Among these, RNA therapeutics have great potentials as radio-sensitisers owing to their ability to target pathways specific to radio-resistance. However, their clinical translation is challenging due to delivery issues. Herein, we report the application of high-density lipoprotein nanoparticle (HDL NPs) as a biocompatible delivery system for a well-established radio-sensitising RNA, miR-34a. A simple/fast microfluidic based technique was used to prepare miR-34a-HDL NPs. Profiling of the radiation response in the UM-SCC-1 head and neck cancer cell line confirmed reduced metabolic activity and increased radiation induced apoptosis upon treatment with miR-34a-HDL NPs. The radio-sensitising properties of miR-34a-HDL NPs were further confirmed in a more biologically relevant co-culture spheroid model of head and neck cancer. Increased apoptotic activity and disrupted cell cycle were induced by miR-34a delivered by HDL NPs. The enhanced radio-biologic effects observed in both 2D and 3D models confirmed the utility of HDL NPs as an efficient delivery system for radio-sensitising RNA.

Development of Octreotide-Loaded Chitosan and Heparin Nanoparticles: Evaluation of Surface Modification Effect on Physicochemical Properties and Macrophage Uptake.

Octreotide (OCT) is a therapeutic peptide which is administered for the treatment of acromegaly. The purpose of this study was to design a new polyethylene glycol (PEG)-conjugated nanoparticle (PEG-NP) to overcome the short half-life and poor stability of OCT. The developed PEG-NPs were compared with non-PEGylated NPs with respect to their size, morphological characteristics, loading efficiency, release profile, and macrophage uptake. The OCT-loaded NPs and PEG-NPs were prepared by ionic complexion of chitosan (Cs) with either heparin (Hp) or PEGylated heparin (PEG-Hp). The chemical structure of PEG-Hp was confirmed by IR and proton nuclear magnetic resonance. Morphological analyses by scanning electron microscopy showed that NPs and PEG-NPs have a uniform shape. Dynamic laser scattering measurements indicated that hydrodynamic diameter of NPs and PEG-NPs were 222.5 ± 10.0 nm and 334.9 ± 6.7 nm, respectively. NPs and PEG-NPs had a positive zeta potential of about 32.5 ± 1.1 mv and 20.6 ± 2.4 mv, respectively. Entrapment efficiency was 61.4 ± 1.0% and 55.7 ± 2.4% for NPs and PEG-NPs, respectively. Compared with the NPs, the PEG-NPs exhibited a slower release profile. Subsequently, fluorescein isothiocyanate-labeled chitosanCs was synthesized and used to evaluate the stealth characteristic of PEG-NPs. In vitro macrophage uptake of fluorescently labeled NPs was measured by flow cytometry.

Preparation, Optimization and Physicochemical Characterization of Aripiprazole Loaded Nano-porous in situ Forming Implant.

BACKGROUND: Multiple applications of antipsychotic agents are the main obstacle in the treatment of schizophrenia. Due to behavioral abnormalities, low compliance is observed in most of the psychotic patients. Designing of new drug delivery systems to overcome compliance problem seems to be necessary. In situ forming implants are a suitable choice for the delivery of antipsychotic agents due to their easy administration process and sustained release kinetics. OBJECTIVE: In this study, a novel poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV) based nanoporous in situ implant system is developed for delivery of aripiprazole. METHODS: Entrapment efficiency, drug loading, rheological features, morphological characteristics and release profile of nano-porous in situ implant system are analyzed in this study. RESULTS: Entrapment efficiency and drug loading coefficient were modeled and impact of different experimental parameters was analyzed using D-optimal study. Entrapment efficiency and drug loading were optimized at 99.32% and 75.23%, respectively. Rheological analyses demonstrated that the developed formulation is a highly cross-linked gel with possible capability for controlled delivery of aripiprazole. According to the FTIR studies, aripiprazole was intact within polymer networks. SEM and light microscopic analyses proved the acceptable morphological characteristics of in situ gels. Release studies demonstrated a biphasic pattern of release. After initial burst release, a sustained pattern was observed for 18 days. The release data was fitted to Korsmeyer-Peppas model and release pattern was found out to be Fickian. In addition, the release profile was compared with novel pluroniccarrageenan based hydrogel system. CONCLUSION: PHBV based in situ forming implant seems to be a novel formulation for delivery of Aripiprazole.

In vitro and in vivo evaluation of paclitaxel-lapatinib-loaded F127 pluronic micelles.

The aim of this study was to evaluate the in vitro and in vivo efficacy of paclitaxel-lapatinib-loaded Pluronic micelles. Lapatinib and pluronic sensitize the cancerous cells to paclitaxel via efflux pump inhibition. In addition, pluronic polymers can trigger intrinsic apoptosis pathways. Furthermore, micellar system can passively target the chemotherapeutic agents by enhanced permeability and retention effect. The paclitaxel-lapatinib-loaded micelles were characterized in means of encapsulation efficacy and size. The in vitro analyses were performed by MTT assay and uptake studies. Real-time imaging and in vivo anti-tumor efficacy studies were also performed. The prepared micelles have acceptable encapsulation ratio and size. Hemolysis assay confirmed that the micelles are hemo-compatible. MTT assay demonstrated that drug-loaded micelles have superior cytotoxicity compared with the naked drugs. The confocal microscopy and flowcytometry analyses showed that micelles are mainly internalized by endocytosis. According to the results of the in vivo imaging, the micelles are accumulated within liver. In vivo anti-tumor efficacy studies confirmed that tumor inhibition of drug-loaded micelles was significant compared to Intaxel®.

Development and Validation of a Rapid RP-HPLC-DAD Analysis Method for the Simultaneous Quantitation of Paclitaxel and Lapatinib in a Polymeric Micelle Formulation.

A robust and rapid analysis method was developed and validated for the simultaneous assay of paclitaxel (PTX) and lapatinib (LPT) in a polymeric micelle formulation as a novel drug delivery system using high-performance liquid chromatography (HPLC). The assay was performed using the C18 MZ-Analytical Column (5 µm, 150 × 4.6 mm, OSD-3) which was protected with the C18 pre-column (5 µm, 4.0 × 4.6 mm, OSD-3). The mobile phase was composed of acetonitrile and water (70/30; V/V) with a flow rate of 0.5 mL/min and detection wavelength of 227 nm. Accuracy was reported as the relative error and was found to be less than 6.8%. The interday assay was evaluated to be 3.22% and 5.76% RSD for PTX and LPT, respectively. The intraday precision was found to be at its maximum value of 5.83% RSD. The limit of detection for both PTX and LPT was found to be 1 µg/mL by means of the newly developed method. The limit of quantitation for PTX and LPT was found to be 5 µg/mL. The calibration curves for both drugs were linear in the concentration range of 5 to 80 µg/mL. In vitro release for both drugs from the polymeric micelle was evaluated using the newly developed analysis method.

Hyaluronic acid-coated liposomes for targeted delivery of paclitaxel, in-vitro characterization and in-vivo evaluation.

Breast cancer is the leading cause of cancer death in women. Chemotherapy is regarded as the most essential strategy in inhibiting the proliferation of tumor cells. Paclitaxel is a widely used taxane; however, the side effects of available Cremophor-based formulations and also the limitations of passive targeting uncovered an essential need to develop tumor-specific targeted nanocarriers. A hyaluronic acid targeted liposomal formulation of paclitaxel was prepared in which, hyaluronic acid was electrostatistically attracted to the surface of liposomes. Liposomes, had a particle size of 106.4±3.2nm, a weakly negative zeta potential of -9.7±0.8mV and an acceptable encapsulation efficiency of 92.1±1.7%. The release profile of liposomes in buffer showed that 95% of PTX was released during 40h. Confocal laser scanning microscopy and flow cytometry analysis showed the greater cellular internalization of coumarin-loaded liposomes compared to free coumarin. MTT assay on 4T1 and T47D cells demonstrated the stronger cytotoxic activity of liposomes in comparison to free paclitaxel. Cell cycle analysis showed that cells were mainly blocked at G2/M phases after 48h treatment with liposomes. In vivo real time imaging on 4T1 tumor-bearing mice revealed that the liposomal formulation mainly accumulated in the tumor area. Liposomes also had better antitumor efficacy against Cremophor-based formulation. In conclusion, hyaluronic acid targeted paclitaxel liposome can serve as a promising targeted formulation of paclitaxel for future cancer chemotherapy.