Low-Molecular-Weight Poly(ethylenimine) Nanogels Loaded with Ultrasmall Iron Oxide Nanoparticles for T1-Weighted MR Imaging-Guided Gene Therapy of Sarcoma

Functional Dendrimer Nanogels for DNA Delivery and Gene Therapy of Tumors

Solving the dilemma between efficacy and cytotoxicity of cationic colloidal vectors is one of the biggest challenges in gene delivery. Cationic dendrimer assemblies with hierarchical structure, smart and biomimetic behaviors have been developed for drug/gene delivery in vivo. Among different dendrimer assemblies, the dendrimer-based nanogels were not intensively studied due to complicated synthesis and unknown properties. Here, for the first time, low-generation dendrimer nanogels with high yield and purity, tunable size, uniform morphology, and good colloidal stability were synthesized using the emulsion-free method, which cannot be obtained by the miniemulsion method. Importantly, the dendrimer nanogels integrate the advantages of low-generation dendrimer and stimuli-responsive polymer, thus achieving dual-active groups, o-hydroxyl amine units, temperature-responsiveness, polyampholyte property, and self-triggered aminolysis. With these unique properties, dendrimer nanogels can "temporarily" acquire high charge density through the covalent crosslinking of low-generation dendrimer for improved DNA compression, promoted cell internalization and lysosomal escape, and efficient DNA delivery, followed by self-triggered aminolysis into small dendrimers to control DNA release, reduce cytotoxicity, and facilitate metabolism in vivo. Compared to high-generation dendrimers, low-generation dendrimer nanogels display higher gene transfection and therapeutic efficacies, and lower side effects simultaneously. This work provides a facile strategy for the preparation of low-generation dendrimer nanogels that break up the contradiction between efficacy and cytotoxicity of cationic colloidal vectors in gene therapy. This innovative approach to construct low-generation dendrimers into smart dendrimer nanogels will have broad applicability in clinical translation.

Current nanocomposite advances for biomedical and environmental application diversity

Nanocomposite materials are emerging as key players in addressing critical challenges in healthcare, energy storage, and environmental remediation. These innovative systems hold great promise in engineering effective solutions for complex problems. Nanocomposites have demonstrated various advantages such as simplicity, versatility, lightweight, and potential cost-effectiveness. By reinforcing synthetic and natural polymers with nanomaterials, a range of nanocomposites have exhibited unique physicochemical properties, biocompatibility, and biodegradability. Current research on nanocomposites has demonstrated promising clinical and translational applications. Over the past decade, the production of nanocomposites has emerged as a critical nano-structuring methodology due to their adaptability and controllable surface structure. This comprehensive review article systematically addresses two principal domains. A comprehensive survey of metallic and nonmetallic nanomaterials (nanofillers), elucidating their efficacy as reinforcing agents in polymeric matrices. Emphasis is placed on the methodical design and engineering principles governing the development of functional nanocomposites. Additionally, the review provides an exhaustive examination of recent noteworthy advancements in industrial, environmental, biomedical, and clinical applications within the realms of nanocomposite materials. Finally, the review concludes by highlighting the ongoing challenges facing nanocomposites in a wide range of applications.

Nanogels-Innovative Drug Carriers for Overcoming Biological Membranes

Nanogels are promising drug delivery systems since they possess undeniable advantages such as high loading capacity for hydrophilic and hydrophobic drugs, stabilization of sensitive drugs, biocompatibility, and biodegradability. The present review summarizes experimental studies related to carriers, drug loading, and membrane transport of nanogels. In particular, the review discusses the properties, advantages, and limitations of polymeric carriers with respect to the behavior of the prepared nanogels in in vivo conditions. The potential of nanogel systems for encapsulation of hydrophilic or hydrophobic drugs and the mechanisms of loading and drug release are also emphasized. Moreover, the challenges related to nanogel transport through the barriers presented in parenteral, oral, ocular, nasal, and dermal routes of administration are also considered.

Effect of Transferrin-Modified Fe3O4 Nanoparticle Targeted Delivery miR-15a-5p Combined With Photothermal Therapy on Lung Cancer

BACKGROUND

Existing studies have shown that transferrin receptor (TfR) is highly expressed on the surface of lung cancer cells, and nanoparticles (NPs) have been widely used as delivery vehicles. The aim of this study was to investigate the effect of the targeted delivery of Fe3O4 NPs modified with transferrin (Tf) compared with photothermal treatment for lung cancer.

METHODS

The morphology and properties of Fe3O4 NPs modified with Tf were tested by internal morphological characterization experiments including transmission electron microscopy, particle size meter infrared spectrometer and other experiments. The delivery of materials was investigated by cell proliferation and apoptosis experiments, and western blot experiment was used to detect yes-associated protein 1(YAP1) protein expression changes after delivering miR-15a-5p. In addition, animal models were constructed to further explore the targeting properties of the material.

RESULTS

The results demonstrated that the nanomaterial has good stability and targeting properties. Meanwhile, we also discovered that the miR-15a-5p carried by NPs can inhibit cell growth after its entry to the lung cancer cells. The effect became more evident when the nanomaterials were assisted with laser therapy, as verified by in vivo and in vitro experiments. In terms of the related mechanism, miR-15a-5p inhibited YAP1 expression, which affected cell proliferation and apoptosis.

CONCLUSION

In this study, Fe3O4 NPs modified with Tf delivered miR-15a-5p in combination with photothermal therapy for lung cancer. In future research, the targeted delivery of Tf and the photothermal synergy of nanomaterials will provide a theoretical basis for cancer treatment.

Functional inorganic nanoparticles in cancer: Biomarker detection, imaging, and therapy

Cancer poses a major global public health challenge. Developing more effective early diagnosis methods and efficient treatment techniques is crucial to enhance early detection sensitivity and treatment outcomes. Nanomaterials offer sensitive, accurate, rapid, and straightforward approaches for cancer detection, diagnosis, and treatment. Inorganic nanoparticles are widely used in medicine because of their high stability, large specific surface area, unique surface properties, and unique quantum size effects. Functional inorganic nanoparticles involve modifying inorganic nanoparticles to enhance their physical properties, enrichment capabilities, and drug-loading efficiency and to minimize toxicity. This Review provides an overview of various types of inorganic nanoparticles and their functionalization characteristics. We then discuss the progress of functional inorganic nanoparticles in cancer biomarker detection and imaging. Furthermore, we discuss the application of functional inorganic nanoparticles in radiotherapy, chemotherapy, gene therapy, immunotherapy, photothermal therapy, photodynamic therapy, sonodynamic therapy, and combination therapy, highlighting their characteristics and advantages. Finally, the toxicity and potential challenges of functional inorganic nanoparticles are analyzed. The purpose of this Review is to explore the application of functional inorganic nanoparticles in diagnosing and treating cancers, while also presenting a new avenue for cancer diagnosis and treatment.

Cell Membrane-Camouflaged Chitosan-Polypyrrole Nanogels Co-Deliver Drug and Gene for Targeted Chemotherapy and Bone Metastasis Inhibition of Prostate Cancer

The development of functional nanoplatforms to improve the chemotherapy outcome and inhibit distal cancer cell metastasis remains an extreme challenge in cancer management. In this work, a human-derived PC-3 cancer cell membrane-camouflaged chitosan-polypyrrole nanogel (CH-PPy NG) platform, which can be loaded with chemotherapeutic drug docetaxel (DTX) and RANK siRNA for targeted chemotherapy and gene silencing-mediated metastasis inhibition of late-stage prostate cancer in a mouse model, is reported. The prepared NGs with a size of 155.8 nm show good biocompatibility, pH-responsive drug release profile, and homologous targeting specificity to cancer cells, allowing for efficient and precise drug/gene co-delivery. Through in-vivo antitumor treatment in a xenografted PC-3 mouse tumor model, it is shown that such a CH-PPy NG-facilitated co-delivery system allows for effective chemotherapy to slow down the tumor growth rate, and effectively inhibits the metastasis of prostate cancer to the bone via downregulation of the RANK/RANKL signaling pathway. The created CH-Ppy NGs may be utilized as a promising platform for enhanced chemotherapy and anti-metastasis treatment of prostate cancer.

Recent progress of iron-based nanomaterials in gene delivery and tumor gene therapy

Gene therapy aims to modify or manipulate gene expression and change the biological characteristics of living cells to achieve the purpose of treating diseases. The safe, efficient, and stable expression of exogenous genes in cells is crucial for the success of gene therapy, which is closely related to the vectors used in gene therapy. Currently, gene therapy vectors are mainly divided into two categories: viral vectors and non-viral vectors. Viral vectors are widely used due to the advantages of persistent and stable expression, high transfection efficiency, but they also have certain issues such as infectivity, high immunological rejection, randomness of insertion mutation, carcinogenicity, and limited vector capacity. Non-viral vectors have the advantages of non-infectivity, controllable chemical structure, and unlimited vector capacity, but the transfection efficiency is low. With the rapid development of nanotechnology, the unique physicochemical properties of nanomaterials have attracted increasing attention in the field of drug and gene delivery. Among many nanomaterials, iron-based nanomaterials have attracted much attention due to their superior physicochemical properties, such as Fenton reaction, magnetic resonance imaging, magnetothermal therapy, photothermal therapy, gene delivery, magnetically-assisted drug delivery, cell and tissue targeting, and so on. In this paper, the research progress of iron-based nanomaterials in gene delivery and tumor gene therapy is reviewed, and the future application direction of iron-based nanomaterials is further prospected.

Redox-Responsive Polymeric Nanoparticle for Nucleic Acid Delivery and Cancer Therapy: Progress, Opportunities, and Challenges

Cancer development and progression of cancer are closely associated with the activation of oncogenes and loss of tumor suppressor genes. Nucleic acid drugs (e.g., siRNA, mRNA, and DNA) are widely used for cancer therapy due to their specific ability to regulate the expression of any cancer-associated genes. However, nucleic acid drugs are negatively charged biomacromolecules that are susceptible to serum nucleases and cannot cross cell membrane. Therefore, specific delivery tools are required to facilitate the intracellular delivery of nucleic acid drugs. In the past few decades, a variety of nanoparticles (NPs) are designed and developed for nucleic acid delivery and cancer therapy. In particular, the polymeric NPs in response to the abnormal redox status in cancer cells have garnered much more attention as their potential in redox-triggered nanostructure dissociation and rapid intracellular release of nucleic acid drugs. In this review, the important genes or signaling pathways regulating the abnormal redox status in cancer cells are briefly introduced and the recent development of redox-responsive NPs for nucleic acid delivery and cancer therapy is systemically summarized. The future development of NPs-mediated nucleic acid delivery and their challenges in clinical translation are also discussed.

Chemoimmunotherapeutic Nanogel for Pre- and Postsurgical Treatment of Malignant Melanoma by Reprogramming Tumor-Associated Macrophages

Surgery is the primary method to treat malignant melanoma; however, the residual microtumors that cannot be resected completely often trigger tumor recurrence, causing tumor-related mortality following melanoma resection. Herein, we developed a feasible strategy based on the combinational chemoimmunotherapy by cross-linking carboxymethyl chitosan (CMCS)-originated polymetformin (PolyMetCMCS) with cystamine to prepare stimuli-responsive nanogel (PMNG) owing to the disulfide bond in cystamine that can be cleaved by the massive glutathione (GSH) in tumor sites. Then, chemotherapeutic agent doxorubicin (DOX) was loaded in PMNG, which was followed by a hyaluronic acid coating to improve the overall biocompatibility and targeting ability of the prepared nanogel (D@HPMNG). Notably, PMNG effectively reshaped the tumor immune microenvironment by reprogramming tumor-associated macrophage phenotypes and recruiting intratumoral CD8+ T cells owing to the inherited immunomodulatory capability of metformin. Consequently, D@HPMNG treatment remarkably suppressed melanoma growth and inhibited its recurrence after surgical resection, proposing a promising solution for overcoming lethal melanoma recurrence.

SPIONs: Superparamagnetic iron oxide-based nanoparticles for the delivery of microRNAi-therapeutics in cancer

Non-coding RNA (ncRNA)-based therapeutics that induce RNA interference (RNAi), such as microRNAs (miRNAs), have drawn considerable attention as a novel class of targeted cancer therapeutics because of their capacity to specifically target oncogenes/protooncogenes that regulate key signaling pathways involved in carcinogenesis, tumor growth and progression, metastasis, cell survival, proliferation, angiogenesis, and drug resistance. However, clinical translation of miRNA-based therapeutics, in particular, has been challenging due to the ineffective delivery of ncRNA molecules into tumors and their uptake into cancer cells. Recently, superparamagnetic iron oxide-based nanoparticles (SPIONs) have emerged as highly effective and efficient for the delivery of therapeutic RNAs to malignant tissues, as well as theranostic (therapy and diagnostic) applications, due to their excellent biocompatibility, magnetic responsiveness, broad functional surface modification, safety, and biodistribution profiles. This review highlights recent advances in the use of SPIONs for the delivery of ncRNA-based therapeutics with an emphasis on their synthesis and coating strategies. Moreover, the advantages and current limitations of SPIONs and their future perspectives are discussed.

Inorganic nanocarriers for siRNA delivery for cancer treatments

RNA interference is one of the emerging methodologies utilized in the treatment of a wide variety of diseases including cancer. This method specifically uses therapeutic RNAs (TpRNAs) like small interfering RNAs (siRNAs) to regulate/silence the cancer-linked genes, thereby minimizing the distinct activities of the cancer cells while aiding in their apoptosis. But, many complications arise during the transport/delivery of these TpRNAs that include poor systemic circulation, instability/degradation inside the body environment, no targeting capacity and also low cellular internalization. These difficulties can be overcome by using nanocarriers to deliver the TpRNAs inside the cancer cells. The following are the various categories of nanocarriers-viral vectors (e.g. lentivirus and adenovirus) and non-viral nanocarriers (self-assembling nanocarriers and inorganic nanocarriers). Viral vectors suffer from disadvantages like high immunogenicity compared to the non-viral nanocarriers. Among non-viral nanocarriers, inorganic nanocarriers gained significant attention as their inherent properties (like magnetic properties) can aid in the effective cellular delivery of the TpRNAs. Most of the prior reports have discussed about the delivery of TpRNAs through self-assembling nanocarriers; however very few have reviewed about their delivery using the inorganic nanoparticles. Therefore, in this review, we have mainly focussed on the delivery of TpRNAs-i.e. siRNA, especially programmed death ligand-1 (PD-L1), survivin, B-cell lymphoma-2 (Bcl-2), vascular endothelial growth factor and other siRNAs using the inorganic nanoparticles-mainly magnetic, metal and silica nanoparticles. Moreover, we have also discussed about the combined delivery of these TpRNAs along with chemotherapeutic drugs (mainly doxorubicin) andin vitroandin vivotherapeutic effectiveness.

Recent trends in preparation and biomedical applications of iron oxide nanoparticles

The iron oxide nanoparticles (IONPs), possessing both magnetic behavior and semiconductor property, have been extensively used in multifunctional biomedical fields due to their biocompatible, biodegradable and low toxicity, such as anticancer, antibacterial, cell labelling activities. Nevertheless, there are few IONPs in clinical use at present. Some IONPs approved for clinical use have been withdrawn due to insufficient understanding of its biomedical applications. Therefore, a systematic summary of IONPs' preparation and biomedical applications is crucial for the next step of entering clinical practice from experimental stage. This review summarized the existing research in the past decade on the biological interaction of IONPs with animal/cells models, and their clinical applications in human. This review aims to provide cutting-edge knowledge involved with IONPs' biological effects in vivo and in vitro, and improve their smarter design and application in biomedical research and clinic trials.

Iron oxide nanoparticle-based nanocomposites in biomedical application

Iron-oxide-based biomagnetic nanocomposites, recognized for their significant properties, have been utilized in MRI and cancer treatment for several decades. The expansion of clinical applications is limited by the occurrence of adverse effects. These limitations are largely attributed to suboptimal material design, resulting in agglomeration, reduced magnetic relaxivity, and inadequate functionality. To address these challenges, various synthesis methods and modification strategies have been used to tailor the size, shape, and properties of iron oxide nanoparticle (FeONP)-based nanocomposites. The resulting modified nanocomposites exhibit significant potential for application in diagnostic, therapeutic, and theranostic contexts, including MRI, drug delivery, and anticancer and antimicrobial activity. Yet, their biosafety profile must be rigorously evaluated. Such efforts will facilitate the broader clinical translation of FeONP-based nanocomposites in biomedical applications.

Evaluation of cardiotoxicity of anthracycline-containing chemotherapy regimens in patients with bone and soft tissue sarcomas: A study of the FDA adverse event reporting system joint single-center real-world experience

OBJECTIVES

To assess the occurrence of cardiotoxicity in patients with tumors receiving anthracycline-based chemotherapy, especially for sarcomas.

METHODS

This study summarized the types and frequency of adverse events (AEs) for three anthracyclines from the FDA adverse event reporting system (FAERS) database. FAERS data from January 2004 to June 2022 were collected and analyzed. Disproportionality analyses, logistic regression, and descriptive analysis were used to compare the differences in cardiac disorders. A retrospective cohort study was conducted in a single center between December 2008 and May 2022. Our hospital-treated patients with bone and soft tissue sarcomas (BSTSs) with anthracycline-containing chemotherapy were analyzed. Serum markers, echocardiography, and electrocardiography have been used to evaluate cardiotoxic events.

RESULTS

One hundred thousand and seventy-five AE reports were obtained for doxorubicin (ADM), epirubicin (EPI), and liposome doxorubicin (L-ADM) from the FAERS database. ADM (OR = 3.1, p < 0.001), EPI (OR = 1.5, p < 0.001), and sarcomas (OR = 1.8, p < 0.001) may increase the probability of cardiac disorders. Cardiac failure, cardiotoxicity, and cardiomyopathy were anthracyclines' top 3 frequent AEs. Among patients receiving ADM-containing therapy, those with ADM applied at doses ≥75 mg/m2 /cycle were more likely to develop cardiac disorders than the other subgroups (OR = 3.5, p < 0.001). Patients younger than 18 are more likely to benefit from dexrazoxane prevention of cardiac failure. Six hundred and eighty-three patients with BSTSs receiving anthracycline-based chemotherapy were analyzed in our center. Patients receiving ADM-containing chemotherapy were likelier to experience abnormalities in serum troponin-T and left ventricular ejection fraction (p < 0.05). 2.0% (6/300) of patients receiving ADM-containing chemotherapy required adjustment of the chemotherapy regimen because of cardiotoxicity, whereas none were in the EPI or L-ADM groups.

CONCLUSIONS AND RELEVANCE

Among patients receiving anthracycline-containing therapy, patients with BSTSs were more likely to develop cardiac disorders than other tumors. In addition, patients with BSTSs receiving ADM chemotherapy had a higher likelihood of cardiotoxic events than those receiving EPI or L-ADM.

Exceedingly Small Magnetic Iron Oxide Nanoparticles for T1 -Weighted Magnetic Resonance Imaging and Imaging-Guided Therapy of Tumors

Magnetic iron oxide nanoparticles (MIONs) based T2 -weighted magnetic resonance imaging (MRI) contrast agents (CAs) are liver-specific with good biocompatibility, but have been withdrawn from the market and replaced with Eovist (Gd-EOB-DTPA) due to their inherent limitations (e.g., susceptibility to artifacts, high magnetic moment, dark signals, long processing time of T2 imaging, and long waiting time for patients after administration). Without the disadvantages of Gd-chelates and MIONs, the recently emerging exceedingly small MIONs (ES-MIONs) (<5 nm) are promising T1 CAs for MRI. However, there are rare review articles focusing on ES-MIONs for T1 -weighted MRI. Herein, the recent progress of ES-MIONs, including synthesis methods (the current basic synthesis methods and improved methods), surface modifications (artificial polymers, natural polymers, zwitterions, and functional protein), T1 -MRI visual strategies (structural remodeling, reversible self-assemblies, metal ions doped, T1 /T2 dual imaging modes, and PET/MRI strategy), and imaging-guided cancer therapy (chemotherapy, gene therapy, ferroptosis therapy, photothermal therapy, photodymatic therapy, radiotherapy, immuotherapy, sonodynamic therapy, and multimode therapy), is summarized. The detailed description of synthesis methods and applications of ES-MIONs in this review is anticipated to attract extensive interest from researchers in different fields and promote their participation in the establishment of ES-MIONs based nanoplatforms for tumor theranostics.

A Biomimetic Nanogel System Restores Macrophage Phagocytosis for Magnetic Resonance Imaging-Guided Synergistic Chemoimmunotherapy of Breast Cancer

Novel strategies to facilitate tumor-specific drug delivery and restore immune attacks remain to be developed to overcome the current limitations of chemotherapy. Herein, a cancer cell membrane (CM)-camouflaged and ultrasmall iron oxide nanoparticles (USIO NPs)-loaded polyethylenimine nanogel (NG) system is reported to co-deliver docetaxel (DTX) and CD47 siRNA (siCD47). The prepared co-delivery system exhibits good colloidal stability, biocompatibility, and r1 relaxivity (1.35 mM-1 s-1 ) and enables redox-responsive release of the loaded DTX in the tumor microenvironment. The NG system realizes homologous targeting delivery of DTX and siCD47 to murine breast cancer cells (4T1 cells) for efficient chemotherapy and gene silencing; thus, inducing immunogenic cell death (ICD) and restoring macrophage phagocytic effect through downregulation of "don't eat me" signals on cancer cells. Likewise, the co-delivery system can also act on macrophages to promote their M1 polarization, which can be combined with DTX-mediated ICD and antibody-mediated immune checkpoint blockade to generate effector T cells for robust chemoimmunotherapy. Further, the USIO NPs-incorporated NG system also allows for magnetic resonance imaging of tumors. The developed biomimetic NG system acting on both cancer cells and macrophages holds a promising potential for macrophage phagocytosis-restored chemoimmunotherapy.

Precision Therapy of Recurrent Breast Cancer through Targeting Different Malignant Tumor Cells with a HER2/CD44-Targeted Hydrogel Nanobot

Heterogeneity and drug resistance of tumor cells are the leading causes of incurability and poor survival for patients with recurrent breast cancer. In order to accurately deliver the biological anticancer drugs to different subtypes of malignant tumor cells for omnidirectional targeted treatment of recurrent breast cancer, a distinct design is demonstrated by embedding liposome-based nanocomplexes containing pro-apoptotic peptide and survivin siRNA drugs (LPR) into Herceptin/hyaluronic acid cross-linked nanohydrogels (Herceptin-HA) to fabricate a HER2/CD44-targeted hydrogel nanobot (named as ALPR). ALPR delivered cargoes to the cells overexpressing CD44 and HER2, followed by Herceptin-HA biodegradation, subsequently, the exposed lipid component containing DOPE fused with the endosomal membrane and released peptide and siRNA into the cytoplasm. These experiments indicated that ALPR can specifically deliver Herceptin, peptide, and siRNA drugs to HER2-positive SKBR-3, triple-negative MDA-MB-231, and HER2-negative drug-resistant MCF-7 human breast cancer cells. ALPR completely inhibited the growth of heterogeneous breast tumors via multichannel synergistic effects: disrupting mitochondria, downregulating the survivin gene, and blocking HER2 receptors on the surface of HER2-positive cells. The present design overcomes the chemical drug resistance and opens a feasible route for the combinative treatment of recurrent breast cancer, even other solid tumors, utilizing different kinds of biological drugs.

Multifunctional Low-Generation Dendrimer Nanogels as an Emerging Probe for Tumor-Specific CT/MR Dual-Modal Imaging

The development of nanoprobes that have amplified enhanced permeability and retention (EPR) effect is crucial for their precise cancer diagnosis performance. Here, we present the development of functional dendrimer-based nanogels (DNGs) with the generation three primary amine-terminated poly(amidoamine) (PAMAM) dendrimers (G3·NH₂) cross-linked by N,N'-bis(acryloyl) cystamine (BAC). The DNGs were prepared through a Michael addition reaction between G3·NH₂ dendrimers and BAC via an inverse microemulsion method and entrapped with gold nanoparticles (Au NPs) to form Au-DNGs. The Au-DNGs were sequentially modified with diethylenetriamine penta-acetic acid (DTPA)-gadolinium (Gd) complex, poly(ethylene glycol) (PEG)-linked arginine-glycine-aspartic (RGD) peptide, and 1,3-propanesultone (1,3-PS). The formed multifunctional RGD-Gd@Au-DNGs-PS (R-G@ADP) possessing an average diameter of 122 nm are colloidally stable and display a high X-ray attenuation coefficient, excellent r₁ relaxivity (9.13 mM^-1 s^-1), desired protein resistance rendered by the zwitterionic modification, and cytocompatibility. With the targeting specificity mediated by RGD and the much better tumor penetration capability than the counterpart material of single dendrimer-entrapped Au NPs, the developed multifunctional R-G@ADP enable targeted and enhanced computed tomography (CT)/magnetic resonance (MR) dual-modal imaging of a pancreatic tumor model in vivo. The current work demonstrates a unique design of targeted and zwitterionic DNGs with prolonged blood circulation time as an emerging nanoprobe for specific tumor CT/MR imaging through amplified passive EPR effect.

Polyethyleneimine-Based Drug Delivery Systems for Cancer Theranostics

With the development of nanotechnology, various types of polymer-based drug delivery systems have been designed for biomedical applications. Polymer-based drug delivery systems with desirable biocompatibility can be efficiently delivered to tumor sites with passive or targeted effects and combined with other therapeutic and imaging agents for cancer theranostics. As an effective vehicle for drug and gene delivery, polyethyleneimine (PEI) has been extensively studied due to its rich surface amines and excellent water solubility. In this work, we summarize the surface modifications of PEI to enhance biocompatibility and functionalization. Additionally, the synthesis of PEI-based nanoparticles is discussed. We further review the applications of PEI-based drug delivery systems in cancer treatment, cancer imaging, and cancer theranostics. Finally, we thoroughly consider the outlook and challenges relating to PEI-based drug delivery systems.

The emerging role of cancer nanotechnology in the panorama of sarcoma

In the field of nanomedicine a multitude of nanovectors have been developed for cancer application. In this regard, a less exploited target is represented by connective tissue. Sarcoma lesions encompass a wide range of rare entities of mesenchymal origin affecting connective tissues. The extraordinary diversity and rarity of these mesenchymal tumors is reflected in their classification, grading and management which are still challenging. Although they include more than 70 histologic subtypes, the first line-treatment for advanced and metastatic sarcoma has remained unchanged in the last fifty years, excluding specific histotypes in which targeted therapy has emerged. The role of chemotherapy has not been completely elucidated and the outcomes are still very limited. At the beginning of the century, nano-sized particles clinically approved for other solid lesions were tested in these neoplasms but the results were anecdotal and the clinical benefit was not substantial. Recently, a new nanosystem formulation NBTXR3 for the treatment of sarcoma has landed in a phase 2-3 trial. The preliminary results are encouraging and could open new avenues for research in nanotechnology. This review provides an update on the recent advancements in the field of nanomedicine for sarcoma. In this regard, preclinical evidence especially focusing on the development of smart materials and drug delivery systems will be summarized. Moreover, the sarcoma patient management exploiting nanotechnology products will be summed up. Finally, an overlook on future perspectives will be provided.

Multifunctional stimuli-responsive hybrid nanogels for cancer therapy: Current status and challenges

With cancer research shifting focus to achieving multifunctionality in cancer treatment strategies, hybrid nanogels are making a rapid rise to the spotlight as novel, multifunctional, stimuli-responsive, and biocompatible cancer therapeutic strategies. They can possess cancer cell-specific cytotoxic effects themselves, carry drugs or enzymes that can produce cytotoxic effects, improve imaging modalities, and target tumor cells over normal cells. Hybrid nanogels bring together a wide range of desirable properties for cancer treatment such as stimuli-responsiveness, efficient loading and protection of molecules such as drugs or enzymes, and effective crossing of cellular barriers among other properties. Despite their promising abilities, hybrid nanogels are still far from being used in the clinic, and their available data remains relatively limited. However, many studies can be done to facilitate this clinical transition. This review is critically summarizing and analyzing the recent information and progress on the use of hybrid nanogels particularly inorganic nanoparticle-based and organic nanoparticle-based hybrid nanogels in the field of oncology and future directions to aid in transferring those results to the clinic. This work concludes that the future of hybrid nanogels is greatly impacted by therapeutic and non-therapeutic factors. Therapeutic factors include the lack of hemocompatibility studies, acute and chronic toxicological studies, and information on agglomeration capability and extent, tumor heterogeneity, interaction with proteins in physiological fluids, endocytosis-exocytosis, and toxicity of the nanogels' breakdown products. Non-therapeutic factors include the lack of clear regulatory guidelines and standardized assays, limitations of animal models, and difficulties associated with good manufacture practices (GMP).

Recent Advances in Functionalized Nanoparticles in Cancer Theranostics

Cancer theranostics is the combination of diagnosis and therapeutic approaches for cancer, which is essential in personalized cancer treatment. The aims of the theranostics application of nanoparticles in cancer detection and therapy are to reduce delays in treatment and hence improve patient care. Recently, it has been found that the functionalization of nanoparticles can improve the efficiency, performance, specificity and sensitivity of the structure, and increase stability in the body and acidic environment. Moreover, functionalized nanoparticles have been found to possess a remarkable theranostic ability and have revolutionized cancer treatment. Each cancer treatment modality, such as MRI-guided gene therapy, MRI-guided thermal therapy, magnetic hyperthermia treatment, MRI-guided chemotherapy, immunotherapy, photothermal and photodynamic therapy, has its strengths and weaknesses, and combining modalities allows for a better platform for improved cancer control. This is why cancer theranostics have been investigated thoroughly in recent years and enabled by functionalized nanoparticles. In this topical review, we look at the recent advances in cancer theranostics using functionalized nanoparticles. Through understanding and updating the development of nanoparticle-based cancer theranostics, we find out the future challenges and perspectives in this novel type of cancer treatment.

One stone, many birds: Recent advances in functional nanogels for cancer nanotheranostics

Inspired by the development of nanomedicine and nanotechnology, more and more possibilities in cancer theranostic have been provided in the last few years. Emerging therapeutic modalities like starvation therapy, chemodynamic therapy, and tumor oxygenation have been integrated with diagnosis, giving a plethora of theranostic nanoagents. Among all of them, nanogels (NGs) show superiority benefiting from their unique attributes: high stability, high water-absorption, large specific surface area, mechanical strength, controlled responsiveness, and high encapsulation capacity. There have been a vast number of investigations supporting various NGs combining drug delivery and multiple bioimaging techniques, encompassing photothermal imaging, photoacoustic imaging, fluorescent imaging, ultrasound imaging, magnetic resonance imaging, and computed tomography. This review summarizes recent advances in functional NGs for theranostic nanomedicine and discusses the challenges and future perspectives of this fast-growing field. This article is categorized under: Therapeutic Approaches and Drug Discovery > Emerging Technologies Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Diagnostic Tools > In Vivo Nanodiagnostics and Imaging.

Recent advances in engineering iron oxide nanoparticles for effective magnetic resonance imaging

Iron oxide nanoparticle (IONP) with unique magnetic property and high biocompatibility have been widely used as magnetic resonance imaging (MRI) contrast agent (CA) for long time. However, a review which comprehensively summarizes the recent development of IONP as traditional T₂ CA and its new application for different modality of MRI, such as T₁ imaging, simultaneous T₂/T₁ or MRI/other imaging modality, and as environment responsive CA is rare. This review starts with an investigation of direction on the development of high-performance MRI CA in both T₂ and T₁ modal based on quantum mechanical outer sphere and Solomon–Bloembergen–Morgan (SBM) theory. Recent rational attempts to increase the MRI contrast of IONP by adjusting the key parameters, including magnetization, size, effective radius, inhomogeneity of surrounding generated magnetic field, crystal phase, coordination number of water, electronic relaxation time, and surface modification are summarized. Besides the strategies to improve r₂ or r₁ values, strategies to increase the in vivo contrast efficiency of IONP have been reviewed from three different aspects, those are introducing second imaging modality to increase the imaging accuracy, endowing IONP with environment response capacity to elevate the signal difference between lesion and normal tissue, and optimizing the interface structure to improve the accumulation amount of IONP in lesion. This detailed review provides a deep understanding of recent researches on the development of high-performance IONP based MRI CAs. It is hoped to trigger deep thinking for design of next generation MRI CAs for early and accurate diagnosis.

•

T₂ contrast capacity of iron oxide nanoparticles (IONPs) could be improved based on quantum mechanical outer sphere theory.

•

IONPs could be expand to be used as effective T₁ CAs by improving q value, extending τ_s, and optimizing interface structure.

•

Environment responsive MRI CAs have been developed to improve the diagnosis accuracy.

•

Introducing other imaging contrast moiety into IONPs could increase the contrast efficiency.

•

Optimizing in vivo behavior of IONPs have been proved to enlarge the signal difference between normal tissue and lesion.

A new strategy for stem cells therapy for erectile dysfunction: Adipose-derived stem cells transfect Neuregulin-1 gene through superparamagnetic iron oxide nanoparticles

PURPOSE

Our previous studies showed that nanotechnology improves derived adipose-derived stem cells (ADSCs) therapy for erectile dysfunction (ED). In this study, the Neuregulin-1(NRG1) gene was transfected into ADSCs with superparamagnetic iron oxide nanoparticles (SPION) further to improve the therapeutic effect of ADSCs on ED.

MATERIALS AND METHODS

ADSCs were isolated from epididymal adipose tissue of Sprague-Dawley rats. The optimal concentration of PEI-SPION (SPION modified with polyethyleneimine) was selected to construct the gene complex. After electrostatic binding of PEI-SPION and DNA, a PEI layer was wrapped to make the PEI-SPION-NRG1-PEI gene transfection complex. Different groups were set up for transfection tests. Lipo2000 transfection reagent was used as the control. PEI-SPION-NRG1-PEI in the experimental group was transfected under an external magnetic field.

RESULTS

When the concentration of PEI-SPION was 10 µg/mL, it had little cytotoxicity, and cell activity was not significantly affected. PEI-SPION-NRG1-PEI forms positively charged nanocomposites with a particle size of 72.6±14.9 nm when N/P ≥8. The PEI-SPION-NRG1-PEI gene complex can significantly improve the transfection efficiency of ADSCs, reaching 26.74%±4.62%, under the action of the external magnetic field. PCR and Western blot showed that the expression level of the NRG1 gene increased significantly, which proved that the transfection was effective.

CONCLUSIONS

PEI-SPION can be used as a vector for NRG1 gene transfection into ADSCs. PEI-SPION-NRG1-PEI packaging has the highest transfection efficiency under the external magnetic field than the other groups. These findings may provide a new strategy for ADSCs therapy for ED.

Synergistic Silencing of Skp2 by siRNA Self-Assembled Nanoparticles as a Therapeutic Strategy for Advanced Prostate Cancer

Advanced prostate cancer, harboring multiple mutations of tumor suppressor genes, is refractory to conventional therapies. Knockout of the Skp2 gene blocks pRb/p53 doubly deficient prostate cancer in mice, which inspired the authors to develop an approach for delivering siRNA that would efficiently silence Skp2 (siSkp2) in vivo. Here, a facile strategy is reported to directly assemble siSkp2 with the natural compound quercetin (Que) into supramolecular nanoparticles (NPs). This carrier-free siSkp2 delivery system could effectively protect siSkp2 from degradation in serum and enhance its cellular internalization. Furthermore, the siSkp2/Que NPs exhibit synergistic effects in Skp2 silencing, because they can degrade the mRNA and protein of Skp2 simultaneously. Indeed, siSkp2/Que NPs remarkably diminish the Skp2 abundance and further inhibit the proliferation and migration of TMU cells (RB1/TP53/KRAS triple mutations) in vitro. The in vivo results further show that i.v. administration of siSkp2/Que NPs efficiently accumulates in tumor sites and strongly inhibits the growth of TMU tumors in nude mice. Importantly, the siSkp2/Que NPs do not induce any abnormality in the treated mice, which suggests satisfactory biocompatibility. Collectively, this study describes a tractable siRNA self-assembled strategy for Skp2 silencing, which might be a promising nanodrug to cure multitherapy-resistant advanced prostate cancer.

Intelligent Design of Ultrasmall Iron Oxide Nanoparticle-Based Theranostics

Rapid advances in nanotechnology have opened up innovative trails to break through the current limitation in clinical treatments of cancer and other critical diseases that plague human beings. Ultrasmall iron oxide nanoparticles (USIO NPs) with sizes smaller than 5 nm have been emerging as a novel category of nanomaterials with increasing interest in the biomedical domains. To overcome their intrinsic shortcomings, naked USIO NPs can be functionalized, clustered, assembled, or incorporated with other nanomaterials to generate various kinds of intelligent nanoplatforms for single-mode or dynamic magnetic resonance (MR) imaging, multimode imaging, as well as imaging-guided precision therapy. In this spotlight on applications, first, we propose the principal aspects in the design and application of USIO NPs for biomedical uses. Second, we cover the recent design strategies of USIO NP-based nanoplatforms mainly developed by our group, describe the rationale on the combination of other functional materials with USIO NPs, and review their resultant applications in theranostics. In addition, we provide herein a perspective on the possible future directions toward USIO NP-based nanoplatforms as smart nanomedicines.