Antitumor Effect of Nanoparticle 131 I-Labeled Arginine-Glycine-Aspartate–Bovine Serum Albumin–Polycaprolactone in Lung Cancer

Cancer Brachytherapy at the Nanoscale: An Emerging Paradigm

Brachytherapy is an established treatment modality that has been globally utilized for the therapy of malignant solid tumors. However, classic therapeutic sealed sources used in brachytherapy must be surgically implanted directly into the tumor site and removed after the requisite period of treatment. In order to avoid the trauma involved in the surgical procedures and prevent undesirable radioactive distribution at the cancerous site, well-dispersed radiolabeled nanomaterials are now being explored for brachytherapy applications. This emerging field has been coined "nanoscale brachytherapy". Despite present-day advancements, an ongoing challenge is obtaining an advanced, functional nanomaterial that concurrently incorporates features of high radiolabeling yield, short labeling time, good radiolabeling stability, and long tumor retention time without leakage of radioactivity to the nontargeted organs. Further, attachment of suitable targeting ligands to the nanoplatforms would widen the nanoscale brachytherapy approach to tumors expressing various phenotypes. Molecular imaging using radiolabeled nanoplatforms enables noninvasive visualization of cellular functions and biological processes in vivo. In vivo imaging also aids in visualizing the localization and retention of the radiolabeled nanoplatforms at the tumor site for the requisite time period to render safe and effective therapy. Herein, we review the advancements over the last several years in the synthesis and use of functionalized radiolabeled nanoplatforms as a noninvasive substitute to standard brachytherapy sources. The limitations of present-day brachytherapy sealed sources are analyzed, while highlighting the advantages of using radiolabeled nanoparticles (NPs) for this purpose. The recent progress in the development of different radiolabeling methods, delivery techniques and nanoparticle internalization mechanisms are discussed. The preclinical studies performed to date are summarized with an emphasis on the current challenges toward the future translation of nanoscale brachytherapy in routine clinical practices.

Radionuclide-based theranostics - a promising strategy for lung cancer

PURPOSE

This review aims to provide a comprehensive overview of the latest literature on personalized lung cancer management using different ligands and radionuclide-based tumor-targeting agents.

BACKGROUND

Lung cancer is the leading cause of cancer-related deaths worldwide. Due to the heterogeneity of lung cancer, advances in precision medicine may enhance the disease management landscape. More recently, theranostics using the same molecule labeled with two different radionuclides for imaging and treatment has emerged as a promising strategy for systemic cancer management. In radionuclide-based theranostics, the target, ligand, and radionuclide should all be carefully considered to achieve an accurate diagnosis and optimal therapeutic effects for lung cancer.

METHODS

We summarize the latest radiotracers and radioligand therapeutic agents used in diagnosing and treating lung cancer. In addition, we discuss the potential clinical applications and limitations associated with target-dependent radiotracers as well as therapeutic radionuclides. Finally, we provide our views on the perspectives for future development in this field.

CONCLUSIONS

Radionuclide-based theranostics show great potential in tailored medical care. We expect that this review can provide an understanding of the latest advances in radionuclide therapy for lung cancer and promote the application of radioligand theranostics in personalized medicine.

The Role of Integrins for Mediating Nanodrugs to Improve Performance in Tumor Diagnosis and Treatment

Integrins are heterodimeric transmembrane proteins that mediate adhesive connections between cells and their surroundings, including surrounding cells and the extracellular matrix (ECM). They modulate tissue mechanics and regulate intracellular signaling, including cell generation, survival, proliferation, and differentiation, and the up-regulation of integrins in tumor cells has been confirmed to be associated with tumor development, invasion, angiogenesis, metastasis, and therapeutic resistance. Thus, integrins are expected to be an effective target to improve the efficacy of tumor therapy. A variety of integrin-targeting nanodrugs have been developed to improve the distribution and penetration of drugs in tumors, thereby, improving the efficiency of clinical tumor diagnosis and treatment. Herein, we focus on these innovative drug delivery systems and reveal the improved efficacy of integrin-targeting methods in tumor therapy, hoping to provide prospective guidance for the diagnosis and treatment of integrin-targeting tumors.

Recent advancement on albumin nanoparticles in treating lung carcinoma

With the advancement of nanotechnology, many different forms of nanoparticles (NPs) are created, which specifically enhance anticancer drug delivery to tumor cells. Albumin bio-macromolecule is a flexible protein carrier for the delivery of drugs that is biodegradable, biocompatible, and non-toxic. As a result, it presents itself as an ideal material for developing nanoparticles for anticancer drug delivery. Toxicological investigations demonstrated that this novel drug delivery technique is safe for use in the human population. Furthermore, drug compatibility with the albumin nanoparticle is remarkable. The robust structure of the nanoparticle, high drug encapsulation, and customizable drug release make it a promising carrier option for the treatment of lung cancer. In this review, we summarize human serum albumin and bovine serum albumin in the targeted delivery of anticancer drugs to lung cancer cells.

(cRGD)2 peptides modified nanoparticles increase tumor-targeting therapeutic effects by co-delivery of albendazole and iodine-131

Albendazole (ABZ), a clinical antiparasitic drug, has shown potential antitumor effects in various tumors. Herein, we prepared dimeric cRGD [(cRGD)2] modified human serum albumin (HSA) nanosystem to co-delivery of albendazole (ABZ) and iodine-131 (131I) for chemoradiotherapy of triple-negative breast cancer (TNBC). HSA@ABZ NPs were synthesized by the self-assembly method. 131I-(cRGD)2/HSA@ABZ NPs were fabricated through covalently binding HSA@ABZ NPs with (cRGD)2 peptides, followed by chloramine T direct labeling with 131I. In vitro therapeutic effects on TNBC (MDA-MB-231 and 4T1 cells) were determined using MTT assay, crystal violet assay, wound-healing assay and western blotting analysis. In vivo treatment was performed using 4T1-bearing mice, and the tumor-targeting efficacy was assessed by gamma imaging. The distribution of NPs was quantitatively analyzed by detecting the gamma counts in tumor and main organs. The nanoparticles possessed negative charge, moderate size and good polydispersity index. Dual responding to pH and redox, the in vitro release rate of ABZ was more than 80% in 72 h. In vitro, NPs inhibited the proliferation of TNBC cells in a concentration-dependent manner and decreased cell migration. Western blotting analysis showed that the NPs, as well as free ABZ, cell-dependently induced autophagy and apoptosis by restraining or promoting the expression of p-p38 and p-JNK MAPK. In vivo, gamma imaging exhibited an earlier and denser radioactivity accumulation in tumor of 131I-(cRGD)2/HSA@ABZ NPs compared to NPs free of (cRGD)2 conjugating. Furthermore, 131I-(cRGD)2/HSA@ABZ NPs significantly suppressed tumor growth by restraining proliferation and promoting apoptosis in vivo. Our study suggested that the nanoparticles we developed enhanced tumor-targeting of ABZ and increased antitumor effects by combination of chemotherapy and radiotherapy.

Utilization of nanotechnology in targeted radionuclide cancer therapy: monotherapy, combined therapy and radiosensitization

The rapid progress of nanomedicine field has a great influence on the different tumor therapeutic trends. It achieves a potential targeting of the therapeutic agent to the tumor site with neglectable exposure of the normal tissue. In nuclear medicine, nanocarriers have been employed for targeted delivery of therapeutic radioisotopes to the malignant tissues. This systemic radiotherapy is employed to overcome the external radiation therapy drawbacks. This review overviews studies concerned with investigation of different nanoparticles as promising carriers for targeted radiotherapy. It discusses the employment of different nanovehicles for achievement of the synergistic effect of targeted radiotherapy with other tumor therapeutic modalities such as hyperthermia and photodynamic therapy. Radiosensitization utilizing different nanosensitizer loaded nanoparticles has also been discussed briefly as one of the nanomedicine approach in radiotherapy.

The Use of Alternative Strategies for Enhanced Nanoparticle Delivery to Solid Tumors

Nanomaterial (NM) delivery to solid tumors has been the focus of intense research for over a decade. Classically, scientists have tried to improve NM delivery by employing passive or active targeting strategies, making use of the so-called enhanced permeability and retention (EPR) effect. This phenomenon is made possible due to the leaky tumor vasculature through which NMs can leave the bloodstream, traverse through the gaps in the endothelial lining of the vessels, and enter the tumor. Recent studies have shown that despite many efforts to employ the EPR effect, this process remains very poor. Furthermore, the role of the EPR effect has been called into question, where it has been suggested that NMs enter the tumor via active mechanisms and not through the endothelial gaps. In this review, we provide a short overview of the EPR and mechanisms to enhance it, after which we focus on alternative delivery strategies that do not solely rely on EPR in itself but can offer interesting pharmacological, physical, and biological solutions for enhanced delivery. We discuss the strengths and shortcomings of these different strategies and suggest combinatorial approaches as the ideal path forward.

Astatine-211 labelled a small molecule peptide: specific cell killing in vitro and targeted therapy in a nude-mouse model

Extensive interest in the development of α-emitting radionuclides astatine-211 (211At) stems from the potential superiority for the treatment of smaller tumors, disseminated disease, and metastatic disease. VP2, a small molecule fusion peptide, can specifically bind to the VPAC1 receptor which is over-expressed in malignant epithelial tumors. In our recent study, we performed the preparation of 211At labelled VP2 through a one-step method. In this work, we explored the targeted radionuclide therapy with [211At]At-SPC-VP2 in vitro and in vivo. The cytotoxicity and specific cell killing of [211At]At-SPC-VP2 were evaluated using the CCK-8 assay. Compared with the [211At]NaAt, the VPAC1-targeted radionuclide compound [211At]At-SPC-VP2 showed more effective cytotoxicity in vitro. Targeted radioactive therapy trial was carried out in non-small-cell lung cancer (NSCLC) xenograft mice. For the therapy experiment, 4 groups of mice were injected via the tail vein with 370 kBq, 550 kBq, 740 kBq, 3 × ∼246 kBq of [211At]At-SPC-VP2, of which the second and third injections were given 4 and 8 days after the first injection, respectively. As controls, animals were treated with saline or 550 kBq [211At]NaAt. The body weight and tumor size of mice were monitored before the administration and every 2 days thereafter. Cytotoxic radiation of partial tissue samples such as kidneys, liver and stomach of mice were assessed by immunohistochemical examination. The tumor growth was inhibited and significantly improved survival was achieved in mice treated with [211At]At-SPC-VP2, two-fold prolongation of survival compared with the control group, which received normal saline or 550 kBq [211At]NaAt. No renal or hepatic toxicity was observed in the mice receiving [211At]At-SPC-VP2, but gastric pathological sections showed 211At uptake in stomach resulting in later toxicity, highlighting the importance of further enhancing the stability of labelled compounds.

Aminosilanized flower-structured superparamagnetic iron oxide nanoparticles coupled to 131I-labeled CC49 antibody for combined radionuclide and hyperthermia therapy of cancer

Combined radionuclide therapy with magnetic nanoparticles-mediated hyperthermia has been under research focus as a promising tumor therapy approach. The objective of this study was to investigate the potential of ¹³¹I-radiolabeled superparamagnetic iron oxide nanoparticles (SPIONs) prepared as the ~40 nm flower-shaped structures with excellent heating efficiency (specific absorption rate at H₀ = 15.9 kA∙m^-1 and resonant frequency of 252 kHz was 123.1 W∙g^-1) for nano-brachytherapy of tumors. ¹³¹I-radiolabeled CC49 antibody attached to SPIONs via reactive groups of 3-aminopropyltriethoxysilane (APTES) provided specificity and long-lasting localized retention after their intratumoral application into LS174T human colon adenocarcinoma xenografts in NOD-SCID mice. The results demonstrate feasibility and effectiveness of magnetic hyperthermia (HT), radionuclide therapy (RT) and their combination (HT + RT) in treating cancer in xenograft models. Combined therapy approach induced a significant (p < 0.01) tumor growth suppression in comparison to untreated groups presented by the tumor volume inhibitory rate (TVIR): 54.38%, 68.77%, 73.00% for HT, RT and HT + RT, respectively in comparison to untreated group and 48.31%, 64,62% and 69,41%, respectively, for the SPIONs-only injected group. Histopathology analysis proved the necrosis and apoptosis in treated tumors without general toxicity. Obtained data support the idea that nano-brachytherapy combined with hyperthermia is a promising approach for effective cancer treatment.

Preclinical SPECT and SPECT-CT in Oncology

Molecular imaging enables both spatial and temporal understanding of the complex biologic systems underlying carcinogenesis and malignant spread. Single-photon emission tomography (SPECT) is a versatile nuclear imaging-based technique with ideal properties to study these processes in vivo in small animal models, as well as to identify potential drug candidates and characterize their antitumor action and potential adverse effects. Small animal SPECT and SPECT-CT (single-photon emission tomography combined with computer tomography) systems continue to evolve, as do the numerous SPECT radiopharmaceutical agents, allowing unprecedented sensitivity and quantitative molecular imaging capabilities. Several of these advances, their specific applications in oncology as well as new areas of exploration are highlighted in this chapter.

A facile approach for fabricating CD44-targeted delivery of hyaluronic acid-functionalized PCL nanoparticles in urethane-induced lung cancer: Bcl-2, MMP-9, caspase-9, and BAX as potential markers

Lung carcinoma ranks highest in cancer-related death (about 20% of total cancer deaths) due to poor prognosis and lack of efficient management therapy. Owing to the lack of effective therapeutic approaches, survival rate of less than 5 years persists over the years among non-small cell lung cancer (NSCLC) patients. Capsaicin (CAP) is well reported for its antiproliferative and antioxidant properties in various literature but lacks an appropriate delivery carrier. The present study was aimed to develop CAP-loaded hyaluronic acid (HA) nanoparticles (NPs) utilizing layer by layer technique to achieve enhanced and precise delivery as well as target specificity. The NPs were evaluated for in vitro release, particle size, zeta potential, and cytotoxicity on A549 cells. The optimized NPs exhibited a particle size of 194 ± 2.90 nm, - 27.87 ± 3.21 mV zeta potential, and 80.70 ± 4.29% release, respectively, over a period of 48 h. Flow cytometric analysis revealed superior performance of HA-PCL-CAP in terms of suppressed cell viability in A549 cell lines when compared with CAP and PCL-CAP. Further, HA-anchored NPs were evaluated in vivo for their therapeutic efficacy in urethane-induced lung carcinoma in rat model. The superlative therapeutic potential of HA-PCL-CAP was advocated from the results of reactive oxygen species and mitochondrial membrane-mediated apoptosis. HA-PCL-CAP-administered groups presented greater therapeutic efficacy as revealed through reduced tumor volume and improved animal survival rate. A greater drug accumulation in tumor tissue as revealed from biodistribution studies evidences targeting potential of HA-PCL-CAP in urethane-induced lung carcinoma. Graphical abstract ᅟ.

Review of Therapeutic Applications of Radiolabeled Functional Nanomaterials

In the last two decades, various nanomaterials have attracted increasing attention in medical science owing to their unique physical and chemical characteristics. Incorporating radionuclides into conventionally used nanomaterials can confer useful additional properties compared to the original material. Therefore, various radionuclides have been used to synthesize functional nanomaterials for biomedical applications. In particular, several α- or β-emitter-labeled organic and inorganic nanoparticles have been extensively investigated for efficient and targeted cancer treatment. This article reviews recent progress in cancer therapy using radiolabeled nanomaterials including inorganic, polymeric, and carbon-based materials and liposomes. We first provide an overview of radiolabeling methods for preparing anticancer agents that have been investigated recently in preclinical studies. Next, we discuss the therapeutic applications and effectiveness of α- or β-emitter-incorporated nanomaterials in animal models and the emerging possibilities of these nanomaterials in cancer therapy.

Mathematical modeling in cancer nanomedicine: a review

Cancer continues to be among the leading healthcare problems worldwide, and efforts continue not just to find better drugs, but also better drug delivery methods. The need for delivering cytotoxic agents selectively to cancerous cells, for improved safety and efficacy, has triggered the application of nanotechnology in medicine. This effort has provided drug delivery systems that can potentially revolutionize cancer treatment. Nanocarriers, due to their capacity for targeted drug delivery, can shift the balance of cytotoxicity from healthy to cancerous cells. The field of cancer nanomedicine has made significant progress, but challenges remain that impede its clinical translation. Several biophysical barriers to the transport of nanocarriers to the tumor exist, and a much deeper understanding of nano-bio interactions is necessary to change the status quo. Mathematical modeling has been instrumental in improving our understanding of the physicochemical and physiological underpinnings of nanomaterial behavior in biological systems. Here, we present a comprehensive review of literature on mathematical modeling works that have been and are being employed towards a better understanding of nano-bio interactions for improved tumor delivery efficacy.