Comparative study on radiolabeling and biodistribution of core-shell silver/polymeric nanoparticles-based theranostics for tumor targeting

Development of Small HN Linked Radionuclide Iodine-125 for Nanocarrier Image Tracing in Mouse Model

Background

Radionuclides have important roles in clinical tumor radiotherapy as they are used to kill tumor cells or as imaging agents for drug tracing. The application of radionuclides has been developing as an increasing number of nanomaterials are used to deliver radionuclides to tumor areas to kill tumor cells. However, promoting the efficient combination of radionuclides and nanocarriers (NCs), enhancing radionuclide loading efficiency, and avoiding environmental pollution caused by radionuclide overuse are important challenges that hinder their further development.

Methods

In the present study, a new small molecule compound (3-[[(2S)-2-hydroxy-3-(4-hydroxyphenyl)-1-carbonyl] amino]-alanine, abbreviation: HN, molecular formula: C12H16N2O5) was synthesized as a linker between radionuclide iodine-125 (125I) and NCs to enable a more efficient binding between NCs and radionuclides.

Results

In vitro evidence indicated that the linker was able to bind 125I with higher efficiency (labeling efficiency >80%) than that of tyrosine, as well as various NCs, such as cellulose nanofibers, metal oxide NCs, and graphene oxide. Single-photon emission computed tomography/computed tomography imaging demonstrated the biological distribution of 125I-labeled NCs in different organs/tissues after administration in mice.

Conclusion

These results showed an improvement in radionuclide labeling efficiency for nanocarriers and provided an approach for nanocarrier image tracing.

Radiolabeled Biodistribution of Expansile Nanoparticles: Intraperitoneal Administration Results in Tumor Specific Accumulation

Nanoparticle biodistribution in vivo is an essential component to the success of nanoparticle-based drug delivery systems. Previous studies with fluorescently labeled expansile nanoparticles, or "eNPs", demonstrated a high specificity of eNPs to tumors that is achieved through a materials-based targeting strategy. However, fluorescent labeling techniques are primarily qualitative in nature and the gold-standard for quantitative evaluation of biodistribution is through radiolabeling. In this manuscript, we synthesize 14C-labeled eNPs to quantitatively evaluate the biodistribution of these particles in a murine model of intraperitoneal mesothelioma via liquid scintillation counting. The results demonstrate a strong specificity of eNPs for tumors that lasts one to 2 weeks postinjection with an overall delivery efficiency to the tumor tissue of 30% of the injected dose which is congruent with prior reports of preclinical efficacy of the technology. Importantly, the route of administration is essential to the eNP's material-based targeting strategy with intraperitoneal administration leading to tumoral accumulation while, in contrast, intravenous administration leads to rapid clearance via the reticuloendothelial system and low tumoral accumulation. A comparison against nanoparticle delivery systems published over the past decade shows that the 30% tumoral delivery efficiency of the eNP is significantly higher than the 0.7% median delivery efficiency of other systems with sufficient quantitative data to define this metric. These results lay a foundation for targeting intraperitoneal tumors and encourage efforts to explore alternative, nonintravenous routes, of delivery to accelerate the translation of nanoparticle therapies to the clinic.

Methods for Radiolabelling Nanoparticles: SPECT Use (Part 1)

The use of nanoparticles (NPs) is rapidly increasing in nuclear medicine (NM) for diagnostic and therapeutic purposes. Their wide use is due to their chemical–physical characteristics and possibility to deliver several molecules. NPs can be synthetised by organic and/or inorganic materials and they can have different size, shape, chemical composition, and charge. These factors influence their biodistribution, clearance, and targeting ability in vivo. NPs can be designed to encapsulate inside the core or bind to the surface several molecules, including radionuclides, for different clinical applications. Either diagnostic or therapeutic radioactive NPs can be synthetised, making a so-called theragnostic tool. To date, there are several methods for radiolabelling NPs that vary depending on both the physical and chemical properties of the NPs and on the isotope used. In this review, we analysed and compared different methods for radiolabelling NPs for single-photon emission computed tomography (SPECT) use.

Radiolabeling and cytotoxicity of monoclonal antibody Isatuximab functionalized silver nanoparticles on the growth of multiple myeloma

The goal of this article was to develop a new therapeutic strategy based on nanotechnology for multiple myeloma (MM) treatment which shows a synergism of different mechanisms. In this concern, 12.9 nm-sized silver nanoparticles (AgNPs) were prepared and functionalized with Isatuximab, anti-MM monoclonal antibody (mAb). Furthermore, the synthesized nanocomposite was radiolabelled with iodine-131 radionuclide and yielded 95.5 ± 1.5%. Then, the synergistic MM-proliferation inhibition efficacy of the radionanocomposite (¹³¹I-Isatuximab/AgNPs) was explored in-vitro in comparison to each single agent. The MTT investigation showed that the antiproliferation effect of ¹³¹I-Isatuximab/AgNPs increased by more than 1.5 fold if compared with Isatuximab, AgNPs, Isatuximab/AgNPs or ¹³¹I-Isatuximab. Additionally, ¹³¹I-Isatuximab/AgNPs exhibited an apoptotic effect on MM cells which was more than that of Isatuximab, AgNPs, Isatuximab/AgNPs or ¹³¹I-Isatuximab by 2, 1.8, 1.7 and 1.5 folds, respectively. In conclusion, the results expressed ¹³¹I-Isatuximab/AgNPs as a potential new anti-MM agent.

Nanocluster-Based Drug Delivery and Theranostic Systems: Towards Cancer Therapy

Over the last decades, the global life expectancy of the population has increased, and so, consequently, has the risk of cancer development. Despite the improvement in cancer therapies (e.g., drug delivery systems (DDS) and theranostics), in many cases recurrence continues to be a challenging issue. In this matter, the development of nanotechnology has led to an array of possibilities for cancer treatment. One of the most promising therapies focuses on the assembly of hierarchical structures in the form of nanoclusters, as this approach involves preparing individual building blocks while avoiding handling toxic chemicals in the presence of biomolecules. This review aims at presenting an overview of the major advances made in developing nanoclusters based on polymeric nanoparticles (PNPs) and/or inorganic NPs. The preparation methods and the features of the NPs used in the construction of the nanoclusters were described. Afterwards, the design, fabrication and properties of the two main classes of nanoclusters, namely noble-metal nanoclusters and hybrid (i.e., hetero) nanoclusters and their mode of action in cancer therapy, were summarized.

Investigation for anticancer activity of the newly synthesized p-Methoxyphenyl maleanilic acid and the diagnostic property of its 99mTc-analogue

PURPOSE

The limitations of the current chemotherapeutics are the main rational to develop and/or explore new anticancer agents and radiolabeled analogues for cancer early diagnosis.

MATERIALS AND METHODS

The newly synthesized p-methoxyphenyl maleanilic acid (MPMA) was prepared, characterized and investigated for its anticancer activity. MPMA screened in-vitro against human hepatocellular carcinoma (HepG-2), human colon carcinoma (HCT-116) and human breast carcinoma (MCF-7) cell lines. Furthermore, the in-vivo screening was performed by radiolabeling of MPMA with technetium-99m (^99mTc) and investigating its biological distribution in normal mice and solid tumor models. Moreover, MPMA and its radiolabeled analogue were docked to Y220C and Y220S mutants of p53 (p53^Y220C and p53^Y220S) in an effort to confirm their affinity to cancer as well as to investigate, virtually, the mechanism of action of MPMA.

RESULTS

The results revealed significant potency of MPMA against HepG-2 cell line (IC₅₀ = 56.2 ± 1.5 µg/mL) if compared to HCT-116 (IC₅₀ = 89.9 ± 1.8 µg/mL) and MCF-7 (IC₅₀ = 104 ± 2.7 µg/mL) cell lines. The radiolabeling yield was optimized to be 90.2 ± 2.1%. The radiolabeled MPMA showed a good localization in the site of solid tumor (15.1 ± 1.6%ID/g) at 2 h post intravenous administration to the tumor bearing mice.

CONCLUSIONS

Collectively, the findings confirmed the potential anticancer activity of MPMA and the possible use of ^99mTc-MPMA for cancer diagnosis and monitoring.

125I–Amoxicillin preparation as a guide tracer for inflammation detection

The objective of this study is to label Amoxicillin with radioactive iodine (125I-AC) via direct electrophilic substitution to act as a promising tracer for inflammation imaging. The highest labeling yield of 80% was achieved after studying all the parameters affecting the labeling reaction using Iodogen (IG) as an oxidizing agent. Molecular Modeling Structure was done using MOE program to predict the suitable 125I position. The product structure was established by a cold iodination reaction using Iodine-127. Biological evaluation of (125I-AC) was carried out using groups of inflamed mice with different exogenous agents such as E.Coli and Turpentine oil. The (125I-AC) shows an in vitro stability of about 97% after 24 h.While doing in vivo studies over 4 h, the tracer stability of 99% was observed.

Radioactive polymeric nanoparticles for biomedical application

Nowadays, emerging radiolabeled nanosystems are revolutionizing medicine in terms of diagnostics, treatment, and theranostics. These radionuclides include polymeric nanoparticles (NPs), liposomal carriers, dendrimers, magnetic iron oxide NPs, silica NPs, carbon nanotubes, and inorganic metal-based nanoformulations. Between these nano-platforms, polymeric NPs have gained attention in the biomedical field due to their excellent properties, such as their surface to mass ratio, quantum properties, biodegradability, low toxicity, and ability to absorb and carry other molecules. In addition, NPs are capable of carrying high payloads of radionuclides which can be used for diagnostic, treatment, and theranostics depending on the radioactive material linked. The radiolabeling process of nanoparticles can be performed by direct or indirect labeling process. In both cases, the most appropriate must be selected in order to keep the targeting properties as preserved as possible. In addition, radionuclide therapy has the advantage of delivering a highly concentrated absorbed dose to the targeted tissue while sparing the surrounding healthy tissues. Said another way, radioactive polymeric NPs represent a promising prospect in the treatment and diagnostics of cardiovascular diseases such as cardiac ischemia, infectious diseases such as tuberculosis, and other type of cancer cells or tumors.

Green tea essential oil encapsulated chitosan nanoparticles-based radiopharmaceutical as a new trend for solid tumor theranosis

The existing study is embarked on investigating the antineoplastic activity of green tea essential oil (GTO) as a natural product. In this regard, GTO was encapsulated in cationic chitosan, nitrogenous-polysaccharide derived by partial deacetylation of chitin, nanoparticles (CS NPs) with entrapment efficiency (EE%) of 81.4 ± 5.7% and a mean particle-size of 30.7 ± 1.13 nm. Moreover, the cytotoxic effect of CS/GTO NPs was evaluated versus human liver (HepG-2), breast (MCF-7) and colon (HCT-116) cancer cell-lines and exhibited a positive impact when compared to bare CS NPs by 3, 2.3 and 1.7 fold for the three cell lines, respectively. More interestingly, CS/GTO NPs were complexed with technethium-99m (^99mTc) radionuclide. With a view to achieve a successful radiolabeling process, different parameters were optimized resulting in a radiolabeling efficiency (RE%) of 93.4 ± 1.2%. Radiopharmacokinetics of the radiolabeled NPs in healthy mice demonstrated a reticuloendothelial system (RES) evading and long blood circulation time up to 4 h. On the other hand, the biodistribution profile in solid tumor models showed 20.3 ± 2.1% localization and cancer cell targeting within just 30 min. On the whole, the reported results encourage the potential use of CS/GTO NPs as a side effect-free anticancer agent and its ^99mTc-analogue as a novel CS/GTO NPs-based diagnostic-radiopharmaceutical for cancer.

Radiolabeling strategies and pharmacokinetic studies for metal based nanotheranostics

Radiolabeled metal-based nanoparticles (MNPs) have drawn considerable attention in the fields of nuclear medicine and molecular imaging, drug delivery, and radiation therapy, given the fact that they can be potentially used as diagnostic imaging and/or therapeutic agents, or even as theranostic combinations. Here, we present a systematic review on recent advances in the design and synthesis of MNPs with major focuses on their radiolabeling strategies and the determinants of their in vivo pharmacokinetics, and together how their intended applications would be impacted. For clarification, we categorize all reported radiolabeling strategies for MNPs into indirect and direct approaches. While indirect labeling simply refers to the use of bifunctional chelators or prosthetic groups conjugated to MNPs for post-synthesis labeling with radionuclides, we found that many practical direct labeling methodologies have been developed to incorporate radionuclides into the MNP core without using extra reagents, including chemisorption, radiochemical doping, hadronic bombardment, encapsulation, and isotope or cation exchange. From the perspective of practical use, a few relevant examples are presented and discussed in terms of their pros and cons. We further reviewed the determinants of in vivo pharmacokinetic parameters of MNPs, including factors influencing their in vivo absorption, distribution, metabolism, and elimination, and discussed the challenges and opportunities in the development of radiolabeled MNPs for in vivo biomedical applications. Taken together, we believe the cumulative advancement summarized in this review would provide a general guidance in the field for design and synthesis of radiolabeled MNPs towards practical realization of their much desired theranostic capabilities. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > Diagnostic Nanodevices Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease.

ICG-Conjugated and 125 I-Labeled Polymeric Micelles with High Biosafety for Multimodality Imaging-Guided Photothermal Therapy of Tumors

Noninvasive multimodality imaging-guided precision photothermal therapy (PTT) is proven to be an effective strategy for tumor theranostics by integrating diagnostics and therapeutics in one nanoplatform. In this study, indocyanine green (ICG)-conjugated and radionuclide iodine-125 (125 I)-labeled polymeric micelles (PEG-PTyr(125 I)-ICG PMs) are strategically prepared by the self-assembly of the ICG-decorated amphiphilic diblock polymer poly(ethylene glycol)-poly(l-tyrosine-125 I)-(indocyanine green) (PEG-PTyr(125 I)-ICG). The as-prepared polymeric micelles exhibit favorable biocompatibility, excellent size/photo/radiolabel stability, a high-photothermal conversion efficiency, a passive tumor-targeting ability, and a fluorescence (FL)/photoacoustic (PA)/single photon emission computed tomography (SPECT) imaging property. After tail intravenous injection, the polymeric micelles can efficiently accumulate at the tumor site and present comprehensive FL/PA/SPECT images with a high sensitivity, excellent spatial resolution, and unlimited tissue penetration under near-infrared (NIR) irradiation. Upon 808 nm laser irradiation, the subsequent precision PTT of tumors can be achieved with minimal cumulative side effects. Thus, this capable multifunctional nanoplatform with simple components and preparation procedures for FL/PA/SPECT multimodality imaging-guided PTT can be a potential candidate for clinical tumor theranostics.

A Chelate-Free Nano-Platform for Incorporation of Diagnostic and Therapeutic Isotopes

PURPOSE

Using our chelate-free, heat-induced radiolabeling (HIR) method, we show that a wide range of metals, including those with radioactive isotopologues used for diagnostic imaging and radionuclide therapy, bind to the Feraheme (FH) nanoparticle (NP), a drug approved for the treatment of iron anemia.

MATERIAL AND METHODS

FH NPs were heated (120°C) with nonradioactive metals, the resulting metal-FH NPs were characterized by inductively coupled plasma mass spectrometry (ICP-MS), dynamic light scattering (DLS), and r1 and r2 relaxivities obtained by nuclear magnetic relaxation spectrometry (NMRS). In addition, the HIR method was performed with [90Y]Y3+, [177Lu]Lu3+, and [64Cu]Cu2+, the latter with an HIR technique optimized for this isotope. Optimization included modifying reaction time, temperature, and vortex technique. Radiochemical yield (RCY) and purity (RCP) were measured using size exclusion chromatography (SEC) and thin-layer chromatography (TLC).

RESULTS

With ICP-MS, metals incorporated into FH at high efficiency were bismuth, indium, yttrium, lutetium, samarium, terbium and europium (>75% @ 120 oC). Incorporation occurred with a small (less than 20%) but statistically significant increases in size and the r2 relaxivity. An improved HIR technique (faster heating rate and improved vortexing) was developed specifically for copper and used with the HIR technique and [64Cu]Cu2+. Using SEC and TLC analyses with [90Y]Y3+, [177Lu]Lu3+ and [64Cu]Cu2+, RCYs were greater than 85% and RCPs were greater than 95% in all cases.

CONCLUSION

The chelate-free HIR technique for binding metals to FH NPs has been extended to a range of metals with radioisotopes used in therapeutic and diagnostic applications. Cations with f-orbital electrons, more empty d-orbitals, larger radii, and higher positive charges achieved higher values of RCY and RCP in the HIR reaction. The ability to use a simple heating step to bind a wide range of metals to the FH NP, a widely available approved drug, may allow this NP to become a platform for obtaining radiolabeled nanoparticles in many settings.

Dispersed graphene materials of biomedical interest and their toxicological consequences

Graphene is one-atom thick nanocarbon displaying a unique honeycomb structure and extensive conjugation. In addition to high surface area to mass ratio, it displays unique optical, thermal, electronic and mechanical properties. Atomic scale tunability of graphene has attracted immense research interest with a prospective utility in electronics, desalination, energy sectors, and beyond. Its intrinsic opto-thermal properties are appealing from the standpoint of multimodal drug delivery, imaging and biosensing applications. Hydrophobic basal plane of sheets can be efficiently loaded with aromatic molecules via non-specific forces. With intense biomedical interest, methods are evolving to produce defect-free and dispersion stable sheets. This review summarizes advancements in synthetic approaches and strategies of stabilizing graphene derivatives in aqueous medium. We have described the interaction of colloidal graphene with cellular and sub-cellular components, and subsequent physiological signaling. Finally, a systematic discussion is provided covering toxicological challenges and possible solutions on utilizing graphene formulations for high-end biomedical applications.

Enhanced Permeation of Methotrexate via Loading into Ultra-permeable Niosomal Vesicles: Fabrication, Statistical Optimization, Ex Vivo Studies, and In Vivo Skin Deposition and Tolerability

The aim of this study was to incorporate methotrexate (MTX) into ultra-permeable niosomal vesicles, containing cremophor RH40 as an edge activator (EA) and polyvinyl alcohol (PVA) as a stabilizer to enhance the drug permeation. Formulae were prepared by ethanol injection method following a Box-Behnken design in order to optimize the formulation variables (EA%, stabilizer %, and sonication time). To investigate the role of both cremophor RH40 and PVA, conventional MTX niosomes and MTX niosomes containing PVA only were fabricated. Drug entrapment efficiency percent (EE%), particle size (PS) analysis, zeta potential (ZP) measurements, and transmission electron microscopy (TEM) were conducted to characterize the vesicles. Cell viability studies and ex vivo permeation experiments of the optimized formula were conducted. Lastly, in vivo skin deposition of MTX from both the optimized formula and MTX solution was performed in rats. Besides, histopathological changes in rat skin were assessed. The optimized MTX ultra-permeable niosomal formula demonstrated spherical morphology, with an EE% of 65.16% and a PS of 453.6 nm. The optimized formula showed better physical stability in comparison with that of the same composition but lacking PVA. The cell viability studies verified the superior cytotoxicity of the optimized formula, and the ex vivo permeation studies revealed its ability to improve the drug permeation. The optimized formula demonstrated a significant deposition of MTX in rat dorsal skin, and histopathological evaluation confirmed the tolerability of the optimized formula in rats upon topical application. Accordingly, ultra-permeable noisomes, as a stable nanosystem, could be promising for effective delivery of MTX.

Silver Nanoparticles: Synthetic Routes, In Vitro Toxicity and Theranostic Applications for Cancer Disease

The large use of nanomaterials in many fields of application and commercial products highlights their potential toxicity on living organisms and the environment, despite their physico-chemical properties. Among these, silver nanoparticles (Ag NPs) are involved in biomedical applications such as antibacterial agents, drug delivery vectors and theranostics agents. In this review, we explain the common synthesis routes of Ag NPs using physical, chemical, and biological methods, following their toxicity mechanism in cells. In particular, we analyzed the physiological cellular pathway perturbations in terms of oxidative stress induction, mitochondrial membrane potential alteration, cell death, apoptosis, DNA damage and cytokines secretion after Ag NPs exposure. In addition, their potential anti-cancer activity and theranostic applications are discussed.

Design and development of microemulsion systems of a new antineoplaston A10 analog for enhanced intravenous antitumor activity: In vitro characterization, molecular docking, 125I-radiolabeling and in vivo biodistribution studies

A10, (3-phenylacetylamino-2,6-piperidinedione), is a natural peptide with broad antineoplastic activity. Recently, in vitro antitumor effect of a new A10 analog [3-(4-methoxybenzoylamino)-2,6-piperidinedione] (MPD) has been verified. However, poor aqueous solubility represents an obstacle towards intravenous formulation of MPD and impedes successful in vivo antitumor activity. To surmount such limitation, MPD microemulsion (MPDME) was developed. A 3¹2² full factorial design using Design-Expert® software was adopted to study the influence of different parameters and select the optimum formulation (MPDME1). Transmission electron microscopy (TEM) displayed spherical droplets of MPDME1. The cytotoxicity of MPDME1 in Michigan Cancer Foundation 7 (MCF-7) breast cancer cell line exceeded that of MPD solution (MPDS) and tamoxifen. Compatibility with injectable diluents, in vitro hemolytic studies and in vivo histopathological examination confirmed the safety of parenteral application of MPDME1. Molecular docking results showed almost same binding affinity of A10, MPD and ¹²⁵I-MPD with histone deacetylase 8 (HDAC8) receptor. Accordingly, radioiodination of MPDME1 and MPDS was done via direct electrophilic substitution reaction. Biodistribution of ¹²⁵I-MPDME1 and ¹²⁵I-MPDS in normal and tumor (ascites and solid) bearing mice showed high accumulation of ¹²⁵I-MPDME1 in tumor tissues. Overall, the results proved that MPDME represents promising parenteral delivery system capable of improving antineoplastic activity of MPD.