Iron oxide nanoparticles and the mechanisms of immune recognition of nanomedicines

Biomimetic Nanocarriers for Cancer Target Therapy

Nanotechnology offers innovative tools for the design of biomimetic nanocarriers for targeted cancer therapy. These nano-systems present several advantages such as cargo's protection and modulation of its release, inclusion of stimuli-responsive elements, and enhanced tumoral accumulation. All together, these nano-systems suffer low therapeutic efficacy in vivo because organisms can recognize and remove foreign nanomaterials. To overcome this important issue, different modifications on nanoparticle surfaces were exploited in order to reach the desired therapeutic efficacy eliciting, also, the response of immune system against cancer cells. For this reason, more recently, a new strategy involving cell membrane-covered nanoparticles for biomedical application has been attracting increasing attention. Membranes from red blood cells, platelets, leukocytes, tumor, and stem cells, have been exploited as biomimetic coatings of nanoparticles for evading clearance or stimulated immune system by maintaining in the same way their targeting capability. In this review, the use of different cell sources as coating of biomimetic nanocarriers for cancer therapy is discussed.

Doxorubicin Delivered Using Nanoparticles Camouflaged with Mesenchymal Stem Cell Membranes to Treat Colon Cancer

PURPOSE

The primary goal of the present study was to design doxorubicin (DOX)-loaded superparamagnetic iron oxide (SPIO) nanoparticles (NPs) coated with mesenchymal stem cell (MSC) membranes and explore their effect on colon cancer in vitro and in vivo.

METHODS

DOX-SPIO NPs were coated with MSC membranes using an extruder, and the morphological characteristics of MSC membrane-camouflaged nanodrug (DOX-SPIO@MSCs) evaluated by transmission electron microscopy (TEM) and NP-tracking analysis. Drug loading and pH response were assessed by UV spectrophotometry. Intracellular colocalization was analyzed using NP-treated MC38 cells stained with 3,3'-dioctadecyloxacarbocyanine perchlorate and Hoechst 33342. Cellular uptake was analyzed using an inverted fluorescence microscope and flow cytometry and cytotoxicity evaluated by cell counting kit-8 assay. Biological compatibility was assessed by hemolysis analysis, immunoactivation test and leukocyte uptake experiments. Furthermore, intravenous injection of chemotherapy drugs into MC38 tumor-bearing C57BL/6 mice was used to study anti-tumor effects.

RESULTS

Typical core-shell NP structures were observed by TEM. Particle size remained stable in fetal bovine serum and phosphate-buffered saline (PBS). Compared with DOX-SPIO, DOX-SPIO@MSCs improved cellular uptake efficiency, enhanced anti-tumor effects, and reduced the immune system response. Animal experiments demonstrated that DOX-SPIO@MSCs enhanced tumor treatment efficacy while reducing systemic side effects.

CONCLUSION

Our experimental results demonstrate that DOX-SPIO@MSCs are a promising targeted nanocarrier for application in treatment of colon cancer.

Engineered Nanomaterials and Type I Allergic Hypersensitivity Reactions

Type I allergic hypersensitivity disorders (atopy) including asthma, atopic dermatitis, allergic rhinitis, and food allergy are on the rise in developed and developing countries. Engineered nanomaterials (ENMs) span a large spectrum of material compositions including carbonic, metals, polymers, lipid-based, proteins, and peptides and are being utilized in a wide range of industries including healthcare and pharmaceuticals, electronics, construction, and food industry, and yet, regulations for the use of ENMs in consumer products are largely lacking. Prior evidence has demonstrated the potential of ENMs to induce and/or aggravate type I allergic hypersensitivity responses. Furthermore, previous studies have shown that ENMs could directly interact with and activate key T-helper 2 (Th2) effector cell types (such as mast cells) and the complement system, which could result in pseudoallergic (non-IgE-mediated) hypersensitivity reactions. Nevertheless, the underlying molecular mechanisms of ENM-mediated induction and/or exacerbation of type I immune responses are poorly understood. In this review, we first highlight key examples of studies that have demonstrated inherent immunomodulatory properties of ENMs in the context of type I allergic hypersensitivity reactions, and most importantly, we attempt to put together the potential molecular mechanisms that could drive ENM-mediated stimulation and/or aggravation of type I allergic hypersensitivity responses.

Hide and Seek: Nanomaterial Interactions With the Immune System

Engineered nanomaterials hold promise for a wide range of applications in medicine. However, safe use of nanomaterials requires that interactions with biological systems, not least with the immune system, are understood. Do nanomaterials elicit novel or unexpected effects, or is it possible to predict immune responses to nanomaterials based on how the immune system handles pathogens? How does the bio-corona of adsorbed biomolecules influence subsequent immune interactions of nanomaterials? How does the grafting of polymers such as poly(ethylene glycol) onto nanomaterial surfaces impact on these interactions? Can ancient immune evasion or “stealth” strategies of pathogens inform the design of nanomaterials for biomedical applications? Can nanoparticles co-opt immune cells to target diseased tissues? The answers to these questions may prove useful for the development of nanomedicines.

A porcine model of complement activation-related pseudoallergy to nano-pharmaceuticals: Pros and cons of translation to a preclinical safety test

Pigs provide a sensitive and quantitative animal model of non-IgE-mediated(pseudoallergic) hypersensitivity reactions (HSRs) caused by liposomes and many other nanoparticulate drugs or drug-carrier nanosystems (nanomedicines). The rapidly arising symptoms, including cardiopulmonary, hemodynamic, hematological, blood chemistry and skin changes, resemble the clinical picture in man undergoing infusion reactions toreactogenic nanoparticles. In addition to summarizing the basic features of the pig CARPA model, thereviewconsiderssome of the advantages and disadvantages of using the modelforpreclinical evaluation of nanomedicine safety.

Fucoidan Prolongs the Circulation Time of Dextran-Coated Iron Oxide Nanoparticles

The magnetic properties and safety of dextran-coated superparamagnetic iron oxide nanoparticles (SPIONs) have facilitated their clinical use as MRI contrast agents and stimulated research on applications for SPIONs in particle imaging and magnetic hyperthermia. The wider clinical potential of SPIONs, however, has been limited by their rapid removal from circulation via the reticuloendothelial system (RES). We explored the possibility of extending SPION circulatory time using fucoidan, a seaweed-derived food supplement, to inhibit RES uptake. The effects of fucoidan on SPION biodistribution were evaluated using ferucarbotran, which in its pharmaceutical formulation (Resovist) targets the RES. Ferucarbotran was radiolabeled at the iron oxide core with technetium-99m (99mTc; t1/2 = 6 h) or zirconium-89 (89Zr; t1/2 = 3.3 days). Results obtained with 99mTc-ferucarbotran demonstrated that administration of fucoidan led to a 4-fold increase in the circulatory half-life (t1/2 slow) from 37.4 to 150 min (n = 4; P < 0.0001). To investigate whether a longer circulatory half-life could lead to concomitant increased tumor uptake, the effects of fucoidan were tested with 89Zr-ferucarbotran in mice bearing syngeneic subcutaneous (GL261) tumors. In this model, the longer circulatory half-life achieved with fucoidan was associated with a doubling in tumor SPION uptake (n = 5; P < 0.001). Fucoidan was also effective in significantly increasing the circulatory half-life of perimag-COOH, a commercially available SPION with a larger hydrodynamic size (130 nm) than ferucarbotran (65 nm). These findings indicate successful diversion of SPIONs away from the hepatic RES and show realistic potential for future clinical applications.

Commentary on the clinical and preclinical dosage limits of interstitially administered magnetic fluids for therapeutic hyperthermia based on current practice and efficacy models

We offer a critique of what constitutes a suitable dosage limit, in both clinical and preclinical studies, for interstitially administered magnetic nanoparticles in order to enable therapeutic hyperthermia under the action of an externally applied alternating magnetic field. We approach this first from the perspective of the currently approved clinical dosages of magnetic nanoparticles in the fields of MRI contrast enhancement, sentinel node detection, iron replacement therapy and magnetic thermoablation. We compare this to a simple analytical model of the achievable hyperthermia temperature rise in both humans and animals based on the interstitially administered dose, the heating and dispersion characteristics of the injected fluid, and the strength and frequency of the applied magnetic field. We show that under appropriately chosen conditions a therapeutic temperature rise is achievable in clinically relevant situations. We also show that in such cases it may paradoxically be harder to achieve the same therapeutic temperature rise in a preclinical model. We comment on the implications for the evidence-based translation of hyperthermia based interventions from the laboratory to the clinic.