Multifunctional Core–Shell Tecto Dendrimers Incorporated with Gold Nanoparticles for Targeted Dual Mode CT/MR Imaging of Tumors

Unlocking the potential of RGD-conjugated gold nanoparticles: a new frontier in targeted cancer therapy, imaging, and metastasis inhibition

In the rapidly evolving field of cancer therapeutics, the potential of gold nanoparticles (AuNPs) conjugated with RGD peptides has emerged as a promising avenue for targeted therapy and imaging. Despite numerous studies demonstrating the effectiveness of RGD-conjugated AuNPs in specifically targeting tumor cells and enhancing radiation therapy (RT), a comprehensive review of these advancements is currently lacking. This review aims to fill this critical gap in the literature. Our analysis reveals that RGD-conjugated AuNPs have shown significant promise in improving the diagnosis and treatment of various types of cancer, including breast cancer. However, the full potential of this technology is yet to be realized. The development of multifunctional nanoplatforms incorporating AuNPs has opened new horizons for targeted therapy, dual-mode imaging, and inhibition of tumor growth and metastasis. This review is of paramount importance as it provides a comprehensive overview of the current state of research in this area, and highlights the areas where further research is needed. It is hoped that this review will inspire further investigations into this promising nanotechnology, ultimately leading to improved cancer diagnosis and therapy. Therefore, the findings presented in this review underscore the potential of AuNPs conjugated with RGD peptides as a revolutionary approach in cancer therapeutics. It is our fervent hope that this review will serve as a catalyst for further research in this exciting field.

Rapid Real-Time PCR Based on Core-Shell Tecto-Dendrimer-Entrapped Au Nanoparticles

Rapid real-time PCR (generally <1 h) has broad prospects. In this study, we synthesized a new type of nanomaterial core-shell tecto-dendrimer coated with Au nanoparticles (Au CSTDs) for research in this field. The experimental results showed that Au CSTDs could significantly shorten the time of real-time PCR (from 72 to 28 min) with different templates, while the detection limit reached 10 copies and the nonspecific amplification was significantly reduced. Furthermore, experimental analyses and theoretical studies using the finite element simulation method confirmed that Au CSTDs function by synergistically enhancing electrostatic adsorption and thermal conductivity. These properties play a key role in improving real-time PCR, especially in particle-particle interactions. This study contributes an advanced method to rapid real-time PCR, which is expected to remarkably improve the efficiency, lower the detection limit, and enhance the specificity of molecular detection.

Structural and Property Characterizations of Dual-Responsive Core-Shell Tecto Dendrimers for Tumor Penetration and Gene Delivery Applications

Core-shell tecto dendrimers (CSTDs) with excellent physicochemical properties and good tumor penetration and gene transfection efficiency have been demonstrated to have the potential to replace high-generation dendrimers in biomedical applications. However, their characterization and related biological properties of CSTDs for enhanced tumor penetration and gene delivery still lack in-depth investigation. Herein, three types of dual-responsive CSTDs are designed for thorough physicochemical characterization and investigation of their tumor penetration and gene delivery efficiency. Three types of CSTDs are prepared through phenylborate ester bonds of phenylboronic acid (PBA)-decorated generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers as cores and monose (galactose, glucose, or mannose)-conjugated G3 PAMAM dendrimers as shells and thoroughly characterized via NMR and other techniques. It is shown that the produced CSTDs display strong correlation signals between the PBA and monose protons, similar hydrodynamic diameters, and dual reactive oxygen species- and pH-responsivenesses. The dual-responsive CSTDs are proven to have structure-dependent tumor penetration property and gene delivery efficiency in terms of small interference RNA for gene silencing and plasmid DNA for gene editing, thus revealing a great potential for different biomedical applications.

Tackling breast cancer with gold nanoparticles: twinning synthesis and particle engineering with efficacy

The World Health Organization identifies breast cancer as the most prevalent cancer despite predominantly affecting women. Surgery, hormonal therapy, chemotherapy, and radiation therapy are the current treatment modalities. Site-directed nanotherapeutics, engineered with multidimensional functionality are now the frontrunners in breast cancer diagnosis and treatment. Gold nanoparticles with their unique colloidal, optical, quantum, magnetic, mechanical, and electrical properties have become the most valuable weapon in this arsenal. Their advantages include facile modulation of shape and size, a high degree of reproducibility and stability, biocompatibility, and ease of particle engineering to induce multifunctionality. Additionally, the surface plasmon oscillation and high atomic number of gold provide distinct advantages for tailor-made diagnosis, therapy or theranostic applications in breast cancer such as photothermal therapy, radiotherapy, molecular labeling, imaging, and sensing. Although pre-clinical and clinical data are promising for nano-dimensional gold, their clinical translation is hampered by toxicity signs in major organs like the liver, kidneys and spleen. This has instigated global scientific brainstorming to explore feasible particle synthesis and engineering techniques to simultaneously improve the efficacy and versatility and widen the safety window of gold nanoparticles. The present work marks the first study on gold nanoparticle design and maneuvering techniques, elucidating their impact on the pharmacodynamics character and providing a clear-cut scientific roadmap for their fast-track entry into clinical practice.

Current status, challenges and prospects of antifouling materials for oncology applications

Targeted therapy has become crucial to modern translational science, offering a remedy to conventional drug delivery challenges. Conventional drug delivery systems encountered challenges related to solubility, prolonged release, and inadequate drug penetration at the target region, such as a tumor. Several formulations, such as liposomes, polymers, and dendrimers, have been successful in advancing to clinical trials with the goal of improving the drug's pharmacokinetics and biodistribution. Various stealth coatings, including hydrophilic polymers such as PEG, chitosan, and polyacrylamides, can form a protective layer over nanoparticles, preventing aggregation, opsonization, and immune system detection. As a result, they are classified under the Generally Recognized as Safe (GRAS) category. Serum, a biological sample, has a complex composition. Non-specific adsorption of chemicals onto an electrode can lead to fouling, impacting the sensitivity and accuracy of focused diagnostics and therapies. Various anti-fouling materials and procedures have been developed to minimize the impact of fouling on specific diagnoses and therapies, leading to significant advancements in recent decades. This study provides a detailed analysis of current methodologies using surface modifications that leverage the antifouling properties of polymers, peptides, proteins, and cell membranes for advanced targeted diagnostics and therapy in cancer treatment. In conclusion, we examine the significant obstacles encountered by present technologies and the possible avenues for future study and development.

Dual-Responsive Core-Shell Tecto Dendrimers Enable Efficient Gene Editing of Cancer Cells to Boost Immune Checkpoint Blockade Therapy

Immune checkpoint blockade (ICB) therapy has become a promising strategy in treating multiple tumor types, but the therapeutic efficacy is still unsatisfactory due to the temporary and inefficient blocking and the poor immune responsiveness. Herein, we report the development of dual reactive oxygen species (ROS)- and pH-responsive core-shell tecto dendrimers loaded with gold nanoparticles (for short, Au CSTDs) to deliver a plasmid-clustered regularly interspersed short palindromic repeats (CRISPR)/Cas9 system for the permanent disruption of the programmed death ligand 1 (PD-L1) gene in cancer cells to boost cancer immunotherapy. In our work, Au CSTDs were constructed using lactobionic acid (LA)-modified generation 5 poly(amidoamine) dendrimers entrapped with gold nanoparticles as cores and phenylboronic acid (PBA)-conjugated generation 3 dendrimers as shells via the formation of responsive phenylborate ester bonds between PBA and LA. The plasmid-CRISPR/Cas9 system can be efficiently compacted and specifically taken up by cancer cells overexpressing sialic acids due to the PBA-mediated targeting and be responsively released in cancer cells by the responsive dissociation of the Au CSTDs, leading to the successful endosomal escape and the efficient knockout of the PD-L1 gene. Further in vivo delivery in a mouse melanoma model reveals that the developed Au CSTDs/plasmid-CRISPR/Cas9 complexes can be specifically accumulated at the tumor site for enhanced computed tomography (CT) imaging of tumors, owing to the X-ray attenuation effect of Au, and disrupt the PD-L1 expression in tumor cells, thus promoting the ICB-based antitumor immunity. The designed dual-responsive Au CSTDs may be developed as a versatile tool for genetic engineering of other cell types to achieve different therapeutic effects for expanded space of biomedical applications.

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.

Image-guided drug delivery in nanosystem-based cancer therapies

The past decades have shown significant advancements in the development of solid tumor treatment. For instance, implementation of nanosystems for drug delivery has led to a reduction in side effects and improved delivery to the tumor region. However, clinical translation has faced challenges, as tumor drug levels are still considered to be inadequate. Interdisciplinary research has resulted in the development of more advanced drug delivery systems. These are coined "smart" due to the ability to be followed and actively manipulated in order to have better control over local drug release. Therefore, image-guided drug delivery can be a powerful strategy to improve drug activity at the target site. Being able to visualize the inflow of the administered smart nanosystem within the tumor gives the potential to determine the right moment to apply the facilitator to initiate drug release. Here we provide an overview of available nanosystems, imaging moieties, and imaging techniques. We discuss preclinical application of these smart drug delivery systems, the strength of image-guided drug delivery, and the future of personalized treatment.

Recent advances in PAMAM dendrimer-based CT contrast agents for molecular imaging and theranostics of cancer

Recent advances and some key developments in the construction of PAMAM dendrimer-based nanoplatforms for tumor CT imaging and theranostics have been reviewed.

Next-generation engineered nanogold for multimodal cancer therapy and imaging: a clinical perspectives

Cancer is one of the significant threats to human life. Although various latest technologies are currently available to treat cancer, it still accounts for millions of death each year worldwide. Thus, creating a need for more developed and novel technologies to combat this deadly condition. Nanoparticles-based cancer therapeutics have offered a promising approach to treat cancer effectively while minimizing adverse events. Among various nanoparticles, nanogold (AuNPs) are biocompatible and have proved their efficiency in treating cancer because they can reach tumors via enhanced permeability and retention effect. The size and shape of the AuNPs are responsible for their diverse therapeutic behavior. Thus, to modulate their therapeutic values, the AuNPs can be synthesized in various shapes, such as spheres, cages, flowers, shells, prisms, rods, clusters, etc. Also, attaching AuNPs with single or multiple targeting agents can facilitate the active targeting of AuNPs to the tumor tissue. The AuNPs have been much explored for photothermal therapy (PTT) to treat cancer. In addition to PTT, AuNPs-based nanoplatforms have been investigated for combinational multimodal therapies in the last few years, including photodynamic therapy, chemotherapy, radiotherapy, immunotherapy, etc., to ablate cancer cells. Thus, the present review focuses on the recent advancements in the functionalization of AuNPs-based nanoconstructs for cancer imaging and therapy using combinatorial multimodal approaches to treat various cancers.

Gold nanomaterials for oral cancer diagnosis and therapy: Advances, challenges, and prospects

Early diagnosis and treatment of oral cancer are vital for patient survival. Since the oral cavity accommodates the second largest and most diverse microbiome community after the gut, the diagnostic and therapeutic approaches with low invasiveness and minimal damage to surrounding tissues are keys to preventing clinical intervention-related infections. Gold nanoparticles (AuNPs) are widely used in the research of cancer diagnosis and therapy due to their excellent properties such as surface-enhanced Raman spectroscopy, surface plasma resonance, controlled synthesis, the plasticity of surface morphology, biological safety, and stability. AuNPs had been used in oral cancer detection reagents, tumor-targeted therapy, photothermal therapy, photodynamic therapy, and other combination therapies for oral cancer. AuNPs-based noninvasive diagnosis and precise treatments further reduce the clinical intervention-related infections. This review is focused on the recent advances in research and application of AuNPs for early screening, diagnostic typing, drug delivery, photothermal therapy, radiotherapy sensitivity treatment, and combination therapy of oral cancer. Distinctive reports from the literature are summarized to highlight the latest advances in the development and application of AuNPs in oral cancer diagnosis and therapy. Finally, this review points out the challenges and prospects of possible applications of AuNPs in oral cancer diagnosis and therapy.

Multimodal Imaging-Guided Spatiotemporal Tracking of Photosensitive Stem Cells for Breast Cancer Treatment

Stem cell therapy has shown great potential in treating a wide range of diseases including cancer. The real-time tracking of stem cells with high spatiotemporal resolution and stable imaging signals remains the bottleneck to evaluate and monitor therapeutic outcomes once transplanted into patients. Here, we developed a photosensitive mesenchymal stem cell (MSC) loaded with mesoporous silica-coated gold nanostars (MGNSs) integrated with indocyanine green for spatiotemporal tracking and imaging-guided photothermal therapy (PTT) in treating breast cancers. The MGNS served as a stable imaging probe with multifunctional properties for photoacoustic imaging (PAI), fluorescence imaging, and PT imaging. Owing to the excellent PT stability of MGNSs, long-term three-dimensional (3D) PAI was achieved to monitor stem cells in real time at the tumor site, while the tumor structure was imaged using 3D B-mode ultrasound imaging. PAI revealed that the photosensitive stem cells reached the widest distribution area at the tumor site post 24 h of intratumoral injection, which was further confirmed via two-dimensional (2D) PT and fluorescence imaging. With this optimal cell distribution window, in vivo studies showed that the photosensitive stem cells via both intratumoral and intravenous injections successfully inhibited breast cancer cell growth and decreased the tumor recurrence rate post PTT. Our results support that this photo-integrated platform with stable optical properties is promising to achieve real-time tracking and measure the cell distribution quantitatively with high spatiotemporal resolution for stem cell therapy.

Engineered cancer cell membranes: An emerging agent for efficient cancer theranostics

For efficient cancer theranostics, surface modification of nanomaterials plays an important role in improving targeting ability and reducing the non-specific interactions with normal tissues. Recently, the biomimetic technology represented by coating of cancer cell membranes (CCMs) has been regarded as a promising method to strengthen the biocompatibility and targeting specificity of nanomaterials. Furthermore, the engineered CCMs (ECCMs) integrated with the natural biological properties of CCMs and specific functions from other cells or proteins have offered more possibilities in the field of cancer theranostics. Herein, the recent progresses in the design and preparation of ECCMs are summarized, and the applications of ECCMs in targeting delivery, activation of immunity, and detection of circulating tumor cells are reviewed. Finally, the current challenges and future perspectives with regard to the development of ECCMs are briefly discussed.

Dendrimer-based nanohybrids in cancer photomedicine

Cancer phototherapy with non-invasiveness and high therapeutical efficiency has emerged as a hot spot research in cancer management. Various nanomaterials have been involved in the development of novel photoactive agents to overcome the current limitations in cancer phototherapy. Dendrimers, as an excellent nanocarrier with unique physicochemical properties, have received extensive attention and much effort has been made in the development of dendrimer-based hybrid platforms for photomedicine applications. Dendrimers can be entrapped with photosensitive agents within their internal cavities and be surface modified with reactive molecules, constructing multifunctional nanoplatforms for cancer treatment. In this review, we concisely survey the design of several different kinds of dendrimer-based nanohybrids for cancer photomedicine applications, and provide an overview of their recent applications in molecular imaging, single-modality photothermal therapy or photodynamic therapy, combination therapy, and theranostics of cancer. In addition, we also briefly discuss the future perspectives in the area of dendrimer-based nanohybrids for cancer photomedicine.