Cancer Immunotherapy Using Bioengineered Micro/Nano Structured Hydrogels.

Hydrogels, a class of materials with a 3D network structure, are widely used in various applications of therapeutic delivery, particularly cancer therapy. Micro and nanogels as miniaturized structures of the bioengineered hydrogels may provide extensive benefits over the common hydrogels in encapsulation and controlled release of small molecular drugs, macromolecular therapeutics, and even cells. Cancer immunotherapy is rapidly developing, and micro/nanostructured hydrogels have gained wide attention regarding their engineered payload release properties that enhance systemic anticancer immunity. Additionally, they are a great candidate due to their local administration properties with a focus on local immune cell manipulation in favor of active and passive immunotherapies. Although applied locally, such micro/nanostructured can also activate systemic antitumor immune responses by releasing nanovaccines safely and effectively inhibiting tumor metastasis and recurrence. However, such hydrogels are mostly used as locally administered carriers to stimulate the immune cells by releasing tumor lysate, drugs, or nanovaccines. In this review, the latest developments in cancer immunotherapy are summarized using micro/nanostructured hydrogels with a particular emphasis on their function depending on the administration route. Moreover, the potential for clinical translation of these hydrogel-based cancer immunotherapies is also discussed.

Synthesis of Fe-Doped Peroxidase Mimetic Nanozymes from Natural Hemoglobin for Colorimetric Biosensing and In Vitro Anticancer Effects.

Despite their efficiency and specificity, the instability of natural enzymes in harsh conditions has inspired researchers to replace them with nanomaterials. In the present study, extracted hemoglobin from blood biowastes was hydrothermally converted to catalytically active carbon nanoparticles (BDNPs). Their application as nanozymes for the colorimetric biosensing of H2O2 and glucose and selective cancer cell-killing ability was demonstrated. Particles that were prepared at 100 °C (BDNP-100) showed the highest peroxidase mimetic activity, with Michaelis-Menten constants (Km) of 11.8 mM and 0.121 mM and maximum reaction rates (Vmax) of 8.56 × 10-8 mol L-1 s-1 and 0.538 × 10-8 mol L-1 s-1, for H2O2 and TMB, respectively. The cascade catalytic reactions, catalyzed by glucose oxidase and BDNP-100, served as the basis for the sensitive and selective colorimetric glucose determination. A linear range of 50-700 µM, a response time of 4 min, a limit of detection (3σ/N) of 40 µM, and a limit of quantification (10σ/N) of 134 µM was achieved. In addition, the reactive oxygen species (ROS)-generating ability of BDNP-100 was employed for evaluating its potential in cancer therapy. Human breast cancer cells (MCF-7), in the forms of monolayer cell cultures and 3D spheroids, were studied by MTT, apoptosis, and ROS assays. The in vitro cellular experiments showed dose-dependent cytotoxicity of BDNP-100 toward MCF-7 cells in the presence of 50 µM of exogenous H2O2. However, no obvious damage was induced to normal cells in the same experimental conditions, verifying the selective cancer cell-killing ability of BDNP-100.

A micropillar array-based microfluidic chip for label-free separation of circulating tumor cells: The best micropillar geometry?

INTRODUCTION: The information derived from the number and characteristics of circulating tumor cells (CTCs), is crucial to ensure appropriate cancer treatment monitoring. Currently, diverse microfluidic platforms have been developed for isolating CTCs from blood, but it remains a challenge to develop a low-cost, practical, and efficient strategy. OBJECTIVES: This study aimed to isolate CTCs from the blood of cancer patients via introducing a new and efficient micropillar array-based microfluidic chip (MPA-Chip), as well as providing prognostic information and monitoring the treatment efficacy in cancer patients. METHODS: We fabricated a microfluidic chip (MPA-Chip) containing arrays of micropillars with different geometries (lozenge, rectangle, circle, and triangle). We conducted numerical simulations to compare velocity and pressure profiles inside the micropillar arrays. Also, we experimentally evaluated the capture efficiency and purity of the geometries using breast and prostate cancer cell lines as well as a blood sample. Moreover, the device's performance was validated on 12 patients with breast cancer (BC) in different states. RESULTS: The lozenge geometry was selected as the most effective and optimized micropillar design for CTCs isolation, providing high capture efficiency (>85 %), purity (>90 %), and viability (97 %). Furthermore, the lozenge MPA-chip was successfully validated by the detection of CTCs from 12 breast cancer (BC) patients, with non-metastatic (median number of 6 CTCs) and metastatic (median number of 25 CTCs) diseases, showing different prognoses. Also, increasing the chemotherapy period resulted in a decrease in the number of captured CTCs from 23 to 7 for the metastatic patient. The MPA-Chip size was only 0.25 cm2 and the throughput of a single chip was 0.5 ml/h, which can be increased by multiple MPA-Chips in parallel. CONCLUSION: The lozenge MPA-Chip presented a novel micropillar geometry for on-chip CTC isolation, detection, and staining, and in the future, the possibilities can be extended to the culture of the CTCs.

A comparative study on biopharmaceutical function of curcumin and miR-34a by multistimuli-responsive nanoniosome carrier: In-vitro and in-vivo.

This research conducted a comparative study on nanoscaled niosomal structures consisting of Tween-80, Tween-60, cholesterol, and dioleoyl-3-trimethylammonium propane (DOTAP). Thin-film hydration technique was used for the preparation and entrapment of curcumin and miRNA in niosomal formulations for enhancing the stability and delivery rate of the agents. Herein, the influence of Tween-80, Tween-60, cholesterol, and DOTAP on the entrapment efficiency (EE%) of curcumin and the physicochemical properties of the carrier are fully discussed. The optimum engineered formulation resulted in a positive charge of +11.23 mV, high EE (100%), smooth surface, spherical shape, small diameter (90 nm), and good stability in physiological buffers. Also, an accelerated cellular uptake, as well as drug release in PBS (pH 7.4, 37°C) after 72 h, were observed. The cytotoxic activity of curcumin (Cur)/miR-34a-loaded nanoparticles was determined by the MTT assay. The results displayed an improved cytotoxic activity of Cur-niosome towards cancer cells compared to free-dispersed Cur. The uptake of Cur-loaded niosome by A280s and A280cp-1 cancer cell lines faced 2.5 folds drop in the concentration compared to its free form. Generally, Cur-niosome exhibits a significant accumulation of superior anti-cancer properties. Likewise, the cytotoxicity of miR-34a-niosome against tumor cells was higher in comparison with its free form. The anti-cancer effects of the gene/drug delivery were investigated in the 4T1 xenografted Balb/C mouse tumor model. According to the in vitro and in vivo results, gene delivery from the modified niosome nanoparticles was distinctly greater than Cur delivery. Therefore, it was concluded that encapsulation of genes in the nano-niosomal delivery system is a promising procedure for the treatment of cancer cells.

Stimuli-Responsive Hydrogels for Local Post-Surgical Drug Delivery.

Currently, surgical operations, followed by systemic drug delivery, are the prevailing treatment modality for most diseases, including cancers and trauma-based injuries. Although effective to some extent, the side effects of surgery include inflammation, pain, a lower rate of tissue regeneration, disease recurrence, and the non-specific toxicity of chemotherapies, which remain significant clinical challenges. The localized delivery of therapeutics has recently emerged as an alternative to systemic therapy, which not only allows the delivery of higher doses of therapeutic agents to the surgical site, but also enables overcoming post-surgical complications, such as infections, inflammations, and pain. Due to the limitations of the current drug delivery systems, and an increasing clinical need for disease-specific drug release systems, hydrogels have attracted considerable interest, due to their unique properties, including a high capacity for drug loading, as well as a sustained release profile. Hydrogels can be used as local drug performance carriers as a means for diminishing the side effects of current systemic drug delivery methods and are suitable for the majority of surgery-based injuries. This work summarizes recent advances in hydrogel-based drug delivery systems (DDSs), including formulations such as implantable, injectable, and sprayable hydrogels, with a particular emphasis on stimuli-responsive materials. Moreover, clinical applications and future opportunities for this type of post-surgery treatment are also highlighted.

Ultrasonic-assisted synthesis and in vitro biological assessments of a novel herceptin-stabilized graphene using three dimensional cell spheroid.

In vivo assays of graphene and its derivatives are big challenges in biological evaluations because they require simultaneous long-term stability in aqueous dispersion and controllable systemic toxicity. Bifunctional graphene nanosheets which have key function in biomedical area are expected to address this challenge. Here, novel bifunctional graphene nanosheets were successfully synthesized in the presence of Herceptin, a natural antibody, using a facile ultrasonic-assisted method. Graphite layers were successfully exfoliated which resulted excellent stability of separated layers in herceptin solution. In aqueous solution, graphene concentration was effectively controlled by varying the herceptin content and sonication time. Furthermore, the toxicity of graphene was tested in both 2D and 3D spheroid cultures. The results showed that graphene toxicity were considerably reduced in spheroid culture compared to the 2D culture data. Moreover, the toxicity behavior of graphene was dependent on the exposed concentration of graphene that the mortality rate was significantly decreased when the concentration of graphene was below 1 µg/mL. This bifunctional graphene which possessed long-term stability in aqueous solutions and induced slight toxicity offers a promising nanostructure in tumor-targeted drug delivery, regenerative medicine and tissue engineering. This proof-of-concept study demonstrates the feasibility of ultrasonic assisted method in one-step synthesis of bifunctional nanomaterials and biostructures for clinical applications.