Nanoshell-mediated photothermal therapy can enhance chemotherapy in inflammatory breast cancer cells

Photothermal therapy: a novel potential treatment for prostate cancer

Prostate cancer (PCa) is a leading cause of cancer-related death in men, and most PCa patients treated with androgen deprivation therapy will progress to metastatic castration-resistant prostate cancer (mCRPC) due to the lack of efficient treatment. Recently, lots of research indicated that photothermal therapy (PTT) was a promising alternative that provided an accurate and efficient prostate cancer therapy. A photothermic agent (PTA) is a basic component of PPT and is divided into organic and inorganic PTAs. Besides, the combination of PTT and other therapies, such as photodynamic therapy (PDT), immunotherapy (IT), chemotherapy (CT), etc., provides an more efficient strategy for PCa therapy. Here, we introduce basic information about PTT and summarize the PTT treatment strategies for prostate cancer. Based on recent works, we think the combination of PPT and other therapies provides a novel possibility for PCa, especially CRPC clinical treatment.

NOTCH Signaling Pathway: Occurrence, Mechanism, and NOTCH-Directed Therapy for the Management of Cancer

It is now well understood that many signaling pathways are vital in carrying out and controlling essential pro-survival and pro-growth cellular functions. The NOTCH signaling pathway, a highly conserved evolutionary signaling pathway, has been thoroughly studied since the discovery of NOTCH phenotypes about 100 years ago in Drosophila melanogaster. Abnormal NOTCH signaling has been linked to the pathophysiology of several diseases, notably cancer. In tumorigenesis, NOTCH plays the role of a "double-edged sword," that is, it may act as an oncogene or as a tumor suppressor gene depending on the nature of the context. However, its involvement in several cancers and inhibition of the same provides targeted therapy for the management of cancer. The use of gamma (γ)-secretase inhibitors and monoclonal antibodies for cancer treatment involved NOTCH receptors inhibition, leading to the possibility of a targeted approach for cancer treatment. Likewise, several natural compounds, including curcumin, resveratrol, diallyl sulfide, and genistein, also play a dynamic role in the management of cancer by inhibition of NOTCH receptors. This review outlines the functions and structure of NOTCH receptors and their associated ligands with the mechanism of the signaling pathway. In addition, it also emphasizes the role of NOTCH-targeted nanomedicine in various cancer treatment strategies.

Multifunctional cell membranes-based nano-carriers for targeted therapies: a review of recent trends and future perspective

Nanotechnology has ignited a transformative revolution in disease detection, prevention, management, and treatment. Central to this paradigm shift is the innovative realm of cell membrane-based nanocarriers, a burgeoning class of biomimetic nanoparticles (NPs) that redefine the boundaries of biomedical applications. These remarkable nanocarriers, designed through a top-down approach, harness the intrinsic properties of cell-derived materials as their fundamental building blocks. Through shrouding themselves in natural cell membranes, these nanocarriers extend their circulation longevity and empower themselves to intricately navigate and modulate the multifaceted microenvironments associated with various diseases. This comprehensive review provides a panoramic view of recent breakthroughs in biomimetic nanomaterials, emphasizing their diverse applications in cancer treatment, cardiovascular therapy, viral infections, COVID-19 management, and autoimmune diseases. In this exposition, we deliver a concise yet illuminating overview of the distinctive properties underpinning biomimetic nanomaterials, elucidating their pivotal role in biomedical innovation. We subsequently delve into the exceptional advantages these nanomaterials offer, shedding light on the unique attributes that position them at the forefront of cutting-edge research. Moreover, we briefly explore the intricate synthesis processes employed in creating these biomimetic nanocarriers, shedding light on the methodologies that drive their development.

Combination cancer imaging and phototherapy mediated by membrane-wrapped nanoparticles

Cancer is a devastating health problem with inadequate treatment options. Many conventional treatments for solid-tumor cancers lack tumor specificity, which results in low efficacy and off-target damage to healthy tissues. Nanoparticle (NP)-mediated photothermal therapy (PTT) is a promising minimally invasive treatment for solid-tumor cancers that has entered clinical trials. Traditionally, NPs used for PTT are coated with passivating agents and/or targeting ligands, but alternative coatings are being explored to enhance tumor specific delivery. In particular, cell-derived membranes have emerged as promising coatings that improve the biointerfacing of photoactive NPs, which reduces their immune recognition, prolongs their systemic circulation and increases their tumor accumulation, allowing for more effective PTT. To maximize treatment success, membrane-wrapped nanoparticles (MWNPs) that enable dual tumor imaging and PTT are being explored. These multifunctional theranostic NPs can be used to enhance tumor detection and/or ensure a sufficient quantity of NPs that have arrived in the tumor prior to laser irradiation. This review summarizes the current state-of-the-art in engineering MWNPs for combination cancer imaging and PTT and discusses considerations for the path toward clinical translation.

Photodynamic and Photothermal Therapies: Synergy Opportunities for Nanomedicine

Tumoricidal photodynamic (PDT) and photothermal (PTT) therapies harness light to eliminate cancer cells with spatiotemporal precision by either generating reactive oxygen species or increasing temperature. Great strides have been made in understanding biological effects of PDT and PTT at the cellular, vascular and tumor microenvironmental levels, as well as translating both modalities in the clinic. Emerging evidence suggests that PDT and PTT may synergize due to their different mechanisms of action, and their nonoverlapping toxicity profiles make such combination potentially efficacious. Moreover, PDT/PTT combinations have gained momentum in recent years due to the development of multimodal nanoplatforms that simultaneously incorporate photodynamically- and photothermally active agents. In this review, we discuss how combining PDT and PTT can address the limitations of each modality alone and enhance treatment safety and efficacy. We provide an overview of recent literature featuring dual PDT/PTT nanoparticles and analyze the strengths and limitations of various nanoparticle design strategies. We also detail how treatment sequence and dose may affect cellular states, tumor pathophysiology and drug delivery, ultimately shaping the treatment response. Lastly, we analyze common experimental design pitfalls that complicate preclinical assessment of PDT/PTT combinations and propose rational guidelines to elucidate the mechanisms underlying PDT/PTT interactions.

Iron Oxide@Mesoporous Silica Core-Shell Nanoparticles as Multimodal Platforms for Magnetic Resonance Imaging, Magnetic Hyperthermia, Near-Infrared Light Photothermia, and Drug Delivery

The design of core-shell nanocomposites composed of an iron oxide core and a silica shell offers promising applications in the nanomedicine field, especially for developing efficient theranostic systems which may be useful for cancer treatments. This review article addresses the different ways to build iron oxide@silica core-shell nanoparticles and it reviews their properties and developments for hyperthermia therapies (magnetically or light-induced), combined with drug delivery and MRI imaging. It also highlights the various challenges encountered, such as the issues associated with in vivo injection in terms of NP-cell interactions or the control of the heat dissipation from the core of the NP to the external environment at the macro or nanoscale.

Study on combination therapy for lung cancer through pemetrexed-loaded mesoporous polydopamine nanoparticles

Lung cancer is one of the most commonly diagnosed cancers, and surgical resection is the optimal choice for the primary lung tumor. But for the secondary lung cancer, chemotherapy and combined radiotherapy still are the main strategies. To realize the combined treatment for non-small cell lung cancer (NSCLC), in this work, a nanoplatform based on pemetrexed (PE)-loaded mesoporous polydopamine (MPDA) nanoparticles were investigated. PE, a special therapeutic drug for NSCLC, was loaded into the MPDA nanoparticles via electrostatic attraction and was encapsulated with polyvinyl pyrrolidone (PVP). The results showed that, when irradiating with 808 nm near-infrared light, the PE loaded MPDA (MPDA@PE@PVP) nanoparticles have excellent photothermal conversion properties, which would result in increase of ambient temperature and could accelerate the release of PE. In vitro cell experiments proved that MPDA@PE@PVP nanoparticles have excellent killing ability for NSCLC A549 cells by the functions of PE and photothermal ability of MPDA nanoparticles. Meanwhile, the intra-cellular reactive oxygen species (ROS) levels of A549 cells in the MPDA@PE@PVP nanoparticle-treated group could be promoted significantly after irradiation, leading to the death of A549 cells. In vivo animal model results showed that MPDA@PE@PVP nanoparticles could gather at the tumor site by enhanced permeability and retention (EPR) effect and have significant inhibition ability for lung tumor by synergistic therapy of chemotherapy, photothermal therapy and photodynamic therapy.

Peptide-based assembled nanostructures that can direct cellular responses

Natural originated materials have been well-studied over the past several decades owing to their higher biocompatibility compared to the traditional polymers. Peptides, consisting of amino acids, are among the most popular programable building blocks, which is becoming a growing interest in nanobiotechnology. Structures assembled using those biomimetic peptides allow the exploration of chemical sequences beyond those been routinely used in biology. In this Review, we discussed the most recent experimental discoveries on the peptide-based assembled nanostructures and their potential application at the cellular level such as drug delivery. In particular, we explored the fundamental principles of peptide self-assembly and the most recent development in improving their interactions with biological systems. We believe that as the fundamental knowledge of the peptide assemblies evolves, the more sophisticated and versatile nanostructures can be built, with promising biomedical applications.

Membrane-wrapped nanoparticles for photothermal cancer therapy

Cancer is a global health problem that needs effective treatment strategies. Conventional treatments for solid-tumor cancers are unsatisfactory because they cause unintended harm to healthy tissues and are susceptible to cancer cell resistance. Nanoparticle-mediated photothermal therapy is a minimally invasive treatment for solid-tumor cancers that has immense promise as a standalone therapy or adjuvant to other treatments like chemotherapy, immunotherapy, or radiotherapy. To maximize the success of photothermal therapy, light-responsive nanoparticles can be camouflaged with cell membranes to endow them with unique biointerfacing capabilities that reduce opsonization, prolong systemic circulation, and improve tumor delivery through enhanced passive accumulation or homotypic targeting. This ensures a sufficient dose of photoresponsive nanoparticles arrives at tumor sites to enable their complete thermal ablation. This review summarizes the state-of-the-art in cell membrane camouflaged nanoparticles for photothermal cancer therapy and provides insights to the path forward for clinical translation.

Ultra-thin layered double hydroxide-mediated photothermal therapy combine with asynchronous blockade of PD-L1 and NR2F6 inhibit hepatocellular carcinoma

Background

The efficacy of immune checkpoint blockade (ICB), in the treatment of hepatocellular carcinoma (HCC), is limited due to low levels of tumor-infiltrating T lymphocytes and deficient checkpoint blockade in this immunologically "cool" tumor. Thus, combination approaches are needed to increase the response rates of ICB and induce synergistic antitumor immunity.

Methods

Herein, we designed a pH-sensitive multifunctional nanoplatform based on layered double hydroxides (LDHs) loaded with siRNA to block the intracellular immune checkpoint NR2F6, together with the asynchronous blockade surface receptor PD-L1 to induce strong synergistic antitumor immunity. Moreover, photothermal therapy (PTT) generated by LDHs after laser irradiation modified an immunologically “cold” microenvironment to potentiate Nr2f6-siRNA and anti-PD-L1 immunotherapy. Flow cytometry was performed to assess the immune responses initiated by the multifunctional nanoplatform.

Results

Under the slightly acidic tumor extracellular environment, PEG detached and the re-exposed positively charged LDHs enhanced tumor accumulation and cell uptake. The accumulated siRNA suppressed the signal of dual protumor activity in both immune and H22 tumor cells by silencing the NR2F6 gene, which further reduced the tumor burden and enhanced systemic antitumor immunity. The responses include enhanced tumor infiltration by CD4⁺ helper T cells, CD8⁺ cytotoxic T cells, and mature dendritic cells; the significantly decreased level of immune suppressed regulator T cells. The therapeutic responses were also attributed to the production of IL-2, IFN-γ, and TNF-α. The prepared nanoparticles also exhibited potential magnetic resonance imaging (MRI) ability, which could serve to guide synergistic immunotherapy treatment.

Conclusions

In summary, the three combinations of PTT, NR2F6 gene ablation and anti-PD-L1 can promote a synergistic immune response to inhibit the progression of primary HCC tumors and prevent metastasis. This study can be considered a proof-of-concept for the targeting of surface and intracellular immune checkpoints to supplement the existing HCC immunotherapy treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01565-9.

Nanoparticles: A New Approach to Upgrade Cancer Diagnosis and Treatment

Traditional cancer therapeutics have been criticized due to various adverse effects and insufficient damage to targeted tumors. The breakthrough of nanoparticles provides a novel approach for upgrading traditional treatments and diagnosis. Actually, nanoparticles can not only solve the shortcomings of traditional cancer diagnosis and treatment, but also create brand-new perspectives and cutting-edge devices for tumor diagnosis and treatment. However, most of the research about nanoparticles stays in vivo and in vitro stage, and only few clinical researches about nanoparticles have been reported. In this review, we first summarize the current applications of nanoparticles in cancer diagnosis and treatment. After that, we propose the challenges that hinder the clinical applications of NPs and provide feasible solutions in combination with the updated literature in the last two years. At the end, we will provide our opinions on the future developments of NPs in tumor diagnosis and treatment.

Advances in Nanomaterial-Mediated Photothermal Cancer Therapies: Toward Clinical Applications

Photothermal therapy (PTT) has attracted extensive research attention as a noninvasive and selective treatment strategy for numerous cancers. PTT functions via photothermal effects induced by converting light energy into heat on near-infrared laser irradiation. Despite the great advances in PTT for cancer treatment, the photothermal therapeutics using laser devise only or non-specific small molecule PTT agents has been limited because of its low photothermal conversion efficiency, concerns about the biosafety of the photothermal agents, their low tumor accumulation, and a heat resistance of specific types of cancer. Using nanomaterials as PTT agents themselves, or for delivery of PTT agents, offers improved therapeutic outcomes with fewer side effects through enhanced photothermal conversion efficiency, accumulation of the PTT agent in the tumor tissue, and, by extension, through combination with other therapies. Herein, we review PTT’s current clinical progress and present the future outlooks for clinical applications. To better understand clinical PTT applications, we describe nanomaterial-mediated photothermal effects and their mechanism of action in the tumor microenvironment. This review also summarizes recent studies of PTT alone or in combination with other therapies. Overall, innovative and strategically designed PTT platforms are promising next-generation noninvasive cancer treatments to move closer toward clinical applications.

NIR-laser-triggered gadolinium-doped carbon dots for magnetic resonance imaging, drug delivery and combined photothermal chemotherapy for triple negative breast cancer

BACKGROUND

Owing to high genetic diversities of tumor cells and low response rate of standard chemotherapy, patients with triple negative breast cancer (TNBC) have short progression-free survivals and poor outcomes, which need to explore an effective approach to improve therapeutic efficacy.

METHODS

Novel gadolinium doped carbon dots (Gd@CDs) have been designed and prepared through hydrothermal method with 3,4-dihydroxyhydrocinnamic acid, 2,2'-(ethylenedioxy)bis(ethylamine) and gadolinium chloride. The synthesized nanostructures were characterized. Taking advantage of good biocompatibility of Gd@CDs, a nanoplatform based on Gd@CDs has been developed to co-deliver chemotherapy drug doxorubicin hydrochloride (Dox) and a near-infrared (NIR) photothermal agent, IR825 for magnetic resonance imaging (MRI) guided photothermal chemotherapy for TNBC.

RESULTS

The as-synthesized Dox@IR825@Gd@CDs displayed favorable MRI ability in vivo. Upon NIR laser irradiation, Dox@IR825@Gd@CDs could convert the NIR light to heat and efficiently inhibit tumor growth through photothermal chemotherapy in vitro and in vivo. Additionally, the impact of photothermal chemotherapy on the murine motor coordination was assessed by rotarod test. Dox@IR825@Gd@CDs presented low toxicity and high photothermal chemotherapy efficiency.

CONCLUSION

A noble theranostic nanoplatform (Dox@IR825@Gd@CDs) was developed that could be tailored to achieve loading of Dox and IR825, intracellular delivery, favorable MRI, excellent combination therapy with photothermal therapy and chemotherapy to enhance therapeutic effect against TNBC cells. This study will provide a promising strategy for the development of Gd-based nanomaterials for MRI and combinational therapy for TNBC.

Nanoparticles for Manipulation of the Developmental Wnt, Hedgehog, and Notch Signaling Pathways in Cancer

The Wnt, Hedgehog, and Notch signaling pathways play a crucial role in early development and the maintenance of adult tissues. When dysregulated, these developmental signaling pathways can drive the formation and progression of cancer by facilitating cell survival, proliferation, and stem-like behavior. While this makes these pathways promising targets for therapeutic intervention, their pharmacological inhibition has been challenging due to the substantial complexity that exists within each pathway and the complicated crosstalk that occurs between the pathways. Recently, several small molecule inhibitors, ribonucleic acid (RNA) molecules, and antagonistic antibodies have been developed that can suppress these signaling pathways in vitro, but many of them face systemic delivery challenges. Nanoparticle-based delivery vehicles can overcome these challenges to enhance the performance and anti-cancer effects of these therapeutic molecules. This review summarizes the mechanisms by which the Wnt, Hedgehog, and Notch signaling pathways contribute to cancer growth, and discusses various nanoparticle formulations that have been developed to deliver small molecules, RNAs, and antibodies to cancer cells to inhibit these signaling pathways and halt tumor progression. This review also outlines some of the challenges that these nanocarriers must overcome to achieve therapeutic efficacy and clinical translation.

Near IR responsive targeted integrated lipid polymer nanoconstruct for enhanced magnolol cytotoxicity in breast cancer

Advances in cancer nanotechnology aim at improving specificity and effectiveness for tumor treatment. Amalgamation of different treatment modalities is expected to provide better cancer combating. Herein, We developed a long circulating nanocarrier comprising trastuzumab (TZB) surface modified polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) co-encapsulating magnolol (Mag) and gold nanoparticles (GNPs). A modified single step nanoprecipitation method was adopted ensuring particle coating with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) while co-encapsulating GNPs. TZB was then anchored on NPs surface using a carbodiimide chemistry. The cytotoxicity of the developed system was evaluated with and without photothermal irradiation. NPs cellular uptake was then followed using confocal microscopical imaging. A hybrid matrix composed of PLGA/TPGS and surface decorated with TZB with a conjugation efficiency of ˃65%, was confirmed via FTIR, ¹HNMR. GNPs could only be included in the NPs, when placed in the organic phase as evidenced by the shifted GNPs surface plasmonic resonance and confirmed via imaging coupled with energy dispersive X-ray analysis. Optimized NPs (136.1 ± 1.3 nm, −8.2 ± 1 mV and Mag encapsulation efficiency of 81.4 ± 1.8%) were able to boost Mag cytotoxicity on breast cancer cells while providing a selective multifunctional therapy with an added photothermal effect.

Gold Nanoshell-Linear Tetrapyrrole Conjugates for Near Infrared-Activated Dual Photodynamic and Photothermal Therapies

Photodynamic therapy (PDT) is a treatment in which photoactive compounds delivered to cancerous tissues are excited with light and then transfer the absorbed energy to adjacent tissue oxygen molecules to generate toxic singlet oxygen (¹O₂). As ¹O₂ is produced only where light and photosensitizers (PSs) are combined, PDT holds promise as a minimally invasive, highly selective treatment for certain cancers. The practical application of PDT requires easily synthesized, water-soluble PSs that have low dark toxicities, high ¹O₂ quantum yields, and efficient absorption of 650-850 nm near-infrared (NIR) light, which deeply penetrates tissue. We recently developed a linear tetrapyrrole metal complex, Pd[DMBil1]-PEG₇₅₀, that meets most of these criteria. This complex is remarkably effective as a PS for PDT against triple-negative breast cancer (TNBC) cells but, critically, it does not absorb NIR light, which is necessary to treat deeper tumors. To enable NIR activation, we synthesized a new derivative, Pd[DMBil1]-PEG₅₀₀₀-SH, which bears a thiol functionality that facilitates conjugation to NIR-absorbing gold nanoshells (NSs). Upon excitation with pulsed 800 nm light, NSs emit two-photon-induced photoluminescence spanning 500-700 nm, which can sensitize the attached PSs to initiate PDT. Additionally, NSs produce heat upon 800 nm irradiation, endowing the NS-PS conjugates with an auxiliary photothermal therapeutic (PTT) capability. Here, we demonstrate that NS-PS conjugates are potent mediators of NIR-activated tandem PDT/PTT against TNBC cells in vitro. We show that Pd[DMBil1]-PEG₅₀₀₀-SH retains the photophysical properties of the parent Pd[DMBil1] complex, and that NS-PS generate ¹O₂ under pulsed 800 nm irradiation, confirming activation of the PSs by photoluminescence emitted from NSs. TNBC cells readily internalize NS PS conjugates, which generate reactive oxygen species in the cells upon pulsed NIR irradiation to damage DNA and induce apoptosis. Together, these findings demonstrate that exploiting photoluminescent NSs as carriers of efficient Pd[DMBil1] PSs is an effective strategy to enable NIR light-activated tandem PDT/PTT.

Cancer Cell Membrane-Coated Nanoparticles for Cancer Management

Cancer is a global health problem in need of transformative treatment solutions for improved patient outcomes. Many conventional treatments prove ineffective and produce undesirable side effects because they are incapable of targeting only cancer cells within tumors and metastases post administration. There is a desperate need for targeted therapies that can maximize treatment success and minimize toxicity. Nanoparticles (NPs) with tunable physicochemical properties have potential to meet the need for high precision cancer therapies. At the forefront of nanomedicine is biomimetic nanotechnology, which hides NPs from the immune system and provides superior targeting capabilities by cloaking NPs in cell-derived membranes. Cancer cell membranes expressing "markers of self" and "self-recognition molecules" can be removed from cancer cells and wrapped around a variety of NPs, providing homotypic targeting and circumventing the challenge of synthetically replicating natural cell surfaces. Compared to unwrapped NPs, cancer cell membrane-wrapped NPs (CCNPs) provide reduced accumulation in healthy tissues and higher accumulation in tumors and metastases. The unique biointerfacing capabilities of CCNPs enable their use as targeted nanovehicles for enhanced drug delivery, localized phototherapy, intensified imaging, or more potent immunotherapy. This review summarizes the state-of-the-art in CCNP technology and provides insight to the path forward for clinical implementation.

IR820-loaded PLGA nanoparticles for photothermal therapy of triple-negative breast cancer

Triple-negative breast cancer (TNBC) accounts for 15-25% of breast cancer cases and lacks expression of the three most common receptors seen on other subtypes of breast cancer. This lack of expression makes TNBC unsusceptible to currently available targeted or hormonal therapies, so new treatment strategies are desperately needed. Photothermal therapy (PTT), which utilizes nanoparticles (NPs) embedded in tumors as exogenous energy absorbers to convert externally applied near-infrared (NIR) light into heat to ablate cancer cells, has shown promise as an alternative strategy. However, it typically uses gold-based NPs that will remain in the body for extended period of time with unknown long-term health effects. To enable PTT with biodegradable, polymeric NPs, we encapsulated the NIR-absorbing dye IR820 in poly(lactic-co-glycolic acid) (PLGA) NPs. We characterized the physicochemical properties of these IR820-loaded PLGA NPs and evaluated their performance as PTT agents using both in vitro and in vivo models of TNBC. The results demonstrate that these NPs are potent mediators of PTT that induce cell death primarily through apoptosis to effectively hinder the growth of TNBC tumors. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 107A: 1702-1712, 2019.

Intelligent Photosensitive Mesenchymal Stem Cells and Cell-Derived Microvesicles for Photothermal Therapy of Prostate Cancer

Targeted delivery of nanomedicines into the tumor site and improving the intratumoral distribution remain challenging in cancer treatment. Here, we report an effective transportation system utilizing both of mesenchymal stem cells (MSCs) and their secreted microvesicles containing assembled gold nanostars (GNS) for targeted photothermal therapy of prostate cancer. The stem cells act as a cell carrier to actively load and assemble GNS into the lysosomes. Accumulation of GNS in the lysosomes facilitates the close interaction of nanoparticles, which could result in a 20 nm red-shift of surface plasmon resonance of GNS with a broad absorption in the near infrared region. Moreover, the MSCs can behave like an engineering factory to pack and release the GNS clusters into microvesicles. The secretion of GNS can be stimulated via light irradiation, providing an external trigger-assisted approach to encapsulate nanoparticles into cell derived microvesicles. In vivo studies demonstrate that GNS-loaded MSCs have an extensive intratumoral distribution, as monitored via photoacoustic imaging, and efficient antitumor effect under light exposure in a prostate-cancer subcutaneous model by intratumoral and intravenous injection. Our work presents a light-responsive transportation approach for GNS in combination of MSCs and their extracellular microvesicles and holds the promise as an effective strategy for targeted cancer therapy including prostate cancer.

A Markedly Improved Synthetic Approach for the Preparation of Multifunctional Au-DNA Nanoparticle Conjugates Modified with Optical and MR Imaging Probes

We describe a new, and vastly superior approach for labeling spherical nucleic acid conjugates (SNAs) with diagnostic probes. SNAs have been shown to provide the unique ability to traverse the cell membrane and deliver surface conjugated DNA into cells while preserving the DNA from nuclease degradation. Our previous work on preparing diagnostically labeled SNAs was labor intensive, relatively low yielding, and costly. Here, we describe a straightforward and facile preparation for labeling SNAs with optical and MR imaging probes with significantly improved physical properties. The synthesis of Gd(III) labeled DNA Au nanoparticle conjugates is achieved by sequential conjugation of 3'-thiol-modified oligonucleotides and cofunctionalization of the particle surface with the subsequent addition of 1,2 diothiolate modified chelates of Gd(III) (abbreviated: DNA-Gd^III@AuNP). This new generation of SNA conjugates has a 2-fold increase of DNA labeling and a 1.4-fold increase in Gd(III) loading compared to published constructs. Furthermore, the relaxivity ( r₁) is observed to increase 4.5-fold compared to the molecular dithiolane-Gd(III) complex, and 1.4-fold increase relative to previous particle constructs where the Gd(III) complexes were conjugated to the oligonucleotides rather than directly to the Au particle. Importantly, this simplified approach (2 steps) exploits the advantages of previous Gd(III) labeled SNA platforms; however, this new approach is scalable and eliminates modification of DNA for attaching the contrast agent, and the particles exhibit improved cell labeling.

Evaluating Nanoshells and a Potent Biladiene Photosensitizer for Dual Photothermal and Photodynamic Therapy of Triple Negative Breast Cancer Cells

Light-activated therapies are ideal for treating cancer because they are non-invasive and highly specific to the area of light application. Photothermal therapy (PTT) and photodynamic therapy (PDT) are two types of light-activated therapies that show great promise for treating solid tumors. In PTT, nanoparticles embedded within tumors emit heat in response to laser light that induces cancer cell death. In PDT, photosensitizers introduced to the diseased tissue transfer the absorbed light energy to nearby ground state molecular oxygen to produce singlet oxygen, which is a potent reactive oxygen species (ROS) that is toxic to cancer cells. Although PTT and PDT have been extensively evaluated as independent therapeutic strategies, they each face limitations that hinder their overall success. To overcome these limitations, we evaluated a dual PTT/PDT strategy for treatment of triple negative breast cancer (TNBC) cells mediated by a powerful combination of silica core/gold shell nanoshells (NSs) and palladium 10,10-dimethyl-5,15-bis(pentafluorophenyl)biladiene-based (Pd[DMBil1]-PEG₇₅₀) photosensitizers (PSs), which enable PTT and PDT, respectively. We found that dual therapy works synergistically to induce more cell death than either therapy alone. Further, we determined that low doses of light can be applied in this approach to primarily induce apoptotic cell death, which is vastly preferred over necrotic cell death. Together, our results show that dual PTT/PDT using silica core/gold shell NSs and Pd[DMBil1]-PEG₇₅₀ PSs is a comprehensive therapeutic strategy to non-invasively induce apoptotic cancer cell death.

Tailor-made PEG-DA-CuS nanoparticles enriched in tumor with the aid of retro Diels-Alder reaction triggered by their intrinsic photothermal property

Introduction

In recent years, near-infrared laser-induced photothermal therapy is being considered as a promising approach to kill tumors owing to its noninvasive nature and excellent antitumor efficiency. However, the lack of ideal photothermal agents hinders further development of this technology.

Materials and methods

Aiming at solving this long-standing obstacle, we report here about the polyethylene glycol (PEG)-DA modified copper sulfide (CuS) nanoparticles (NPs) (PEG-DA-CuS NPs), a kind of semiconductor photothermal agents that show excellent photothermal stability and high heat conversion efficiency.

Results and discussion

Owing to the surrounding PEG, the water solubility of CuS NPs was significantly improved when circulating in blood in the body. When the NPs reached the tumors and were irradiated by a 1,064 nm laser (1 W/cm², 10 minutes), the local temperature increased above 90°C, triggering the retro Diels–Alder reaction. After the release of PEG chain, CuS NPs soon formed aggregates and enriched the tumor via the enhanced permeability and retention effect, promoting the efficacy of photothermal therapy.

Conclusion

Therefore, we believe PEG-DA-CuS NPs are able to serve as a kind of cytotoxic and efficient photothermal agent to kill cancer.

Metallic Nanoparticles for Cancer Immunotherapy

Cancer immunotherapy, or the utilization of the body's immune system to attack tumor cells, has gained prominence over the past few decades as a viable cancer treatment strategy. Recently approved immunotherapeutics have conferred remission upon patients with previously bleak outcomes and have expanded the number of tools available to treat cancer. Nanoparticles -including polymeric, liposomal, and metallic formulations - naturally traffic to the spleen and lymph organs and the relevant immune cells therein, making them good candidates for delivery of immunotherapeutic agents. Metallic nanoparticle formulations in particular are advantageous because of their potential for dense surface functionalization and their capability for optical or heat based therapeutic methods. Many research groups have investigated the potential of nanoparticle-mediated delivery platforms to improve the efficacy of immunotherapies. Despite the significant preclinical successes demonstrated by many of these platforms over the last twenty years, few metallic nanoparticles have successfully entered clinical trials with none achieving FDA approval for cancer therapy. In this review, we will discuss preclinical research and clinical trials involving metallic nanoparticles (MNPs) for cancer immunotherapy applications and discuss the potential for clinical translation of MNPs.

Investigating the role of Hedgehog/GLI1 signaling in glioblastoma cell response to temozolomide

Resistance to chemotherapy substantially hinders successful glioblastoma (GBM) treatment, contributing to an almost 100% mortality rate. Resistance to the frontline chemotherapy, temozolomide (TMZ), arises from numerous signaling pathways that are deregulated in GBM, including Hedgehog (Hh) signaling. Here, we investigate suppression of Hh signaling as an adjuvant to TMZ using U87-MG and T98G cell lines as in vitro models of GBM. We found that silencing GLI1 with siRNA reduces cell metabolic activity by up to 30% in combination with TMZ and reduces multidrug efflux activity by 2.5-fold. Additionally, pharmacological GLI inhibition modulates nuclear p53 levels and decreases MGMT expression in combination with TMZ. While we surprisingly found that silencing GLI1 does not induce apoptosis in the absence of TMZ co-treatment, we discovered silencing GLI1 without TMZ co-treatment induces senescence as evidenced by a significant 2.3-fold increase in senescence associated β-galactosidase staining, and this occurs in a loss of PTEN-dependent manner. Finally, we show that GLI inhibition increases apoptosis in glioma stem-like cells by up to 6.8-fold in combination with TMZ, and this reduces the size and number of neurospheres grown from glioma stem-like cells. In aggregate, our data warrant the continued investigation of Hh pathway inhibitors as adjuvants to TMZ chemotherapy and highlight the importance of identifying signaling pathways that determine whether co-treatment will be successful.

Fluorescent, Plasmonic, and Radiotherapeutic Properties of the 177Lu-Dendrimer-AuNP-Folate-Bombesin Nanoprobe Located Inside Cancer Cells

The integration of fluorescence and plasmonic properties into one molecule is of importance in developing multifunctional imaging and therapy nanoprobes. The aim of this research was to evaluate the fluorescent properties and the plasmonic–photothermal, therapeutic, and radiotherapeutic potential of ¹⁷⁷Lu–dendrimer conjugated to folate and bombesin with gold nanoparticles in the dendritic cavity (¹⁷⁷Lu–DenAuNP–folate–bombesin) when it is internalized in T47D breast cancer cells. The intense near-Infrared (NIR) fluorescence emitted at 825 nm from the conjugate inside cells corroborated the usefulness of DenAuNP–folate–bombesin for optical imaging. After laser irradiation, the presence of the nanosystem in cells caused a significant increase in the temperature of the medium (46.8°C, compared to 39.1°C without DenAuNP–folate–bombesin, P < 0.05), resulting in a significant decrease in cell viability (down to 16.51% ± 1.52%) due to the ¹⁷⁷Lu–DenAuNP–folate–bombesin plasmonic properties. After treatment with ¹⁷⁷Lu–DenAuNP–folate–bombesin, the T47D cell viability decreased 90% because of the radiation-absorbed dose (63.16 ± 4.20 Gy) delivered inside the cells. The ¹⁷⁷Lu–DenAuNP–folate–bombesin nanoprobe internalized in cancer cells exhibited properties suitable for optical imaging, plasmonic–photothermal therapy, and targeted radiotherapy.

Resonance Energy Transfer-Promoted Photothermal and Photodynamic Performance of Gold-Copper Sulfide Yolk-Shell Nanoparticles for Chemophototherapy of Cancer

Gold (Au) core@void@copper sulfide (CuS) shell (Au-CuS) yolk-shell nanoparticles (YSNPs) were prepared in the present study for potential chemo-, photothermal, and photodynamic combination therapy, so-called "chemophototherapy". The resonance energy transfer (RET) process was utilized in Au-CuS YSNPs to achieve both enhanced photothermal and photodynamic performance compared with those of CuS hollow nanoparticles (HNPs). A series of Au nanomaterials as cores that had different localized surface plasmon resonance (LSPR) absorption peaks at 520, 700, 808, 860, and 980 nm were embedded in CuS HNPs to screen the most effective Au-CuS YSNPs according to the RET process. Thermoresponsive polymer was fabricated on these YSNPs' surface to allow for controlled drug release. Au₈₀₈-CuS and Au₉₈₀-CuS YSNPs were found capable of inducing the largest temperature elevation and producing the most significant hydroxyl radicals under 808 and 980 nm laser irradiation, respectively, which could accordingly cause the most severe 4T1 cell injury through oxidative stress mechanism. Moreover, doxorubicin-loaded (Dox-loaded) P(NIPAM-co-AM)-coated Au₉₈₀-CuS (p-Au₉₈₀-CuS@Dox) YSNPs could more efficiently kill cells than unloaded particles upon 980 nm laser irradiation. After intravenous administration to 4T1 tumor-bearing mice, p-Au₉₈₀-CuS YSNPs could significantly accumulate in the tumor and effectively inhibit the tumor growth after 980 nm laser irradiation, and p-Au₉₈₀-CuS@Dox YSNPs could further potentiate the inhibition efficiency and exhibit excellent in vivo biocompatibility. Taken together, this study sheds light on the rational design of Au-CuS YSNPs to offer a promising candidate for chemophototherapy.

Multibranched Gold Nanoparticles with Intrinsic LAT-1 Targeting Capabilities for Selective Photothermal Therapy of Breast Cancer

Because of the critical role of the large neutral amino acid transporter-1 (LAT-1) in promoting tumor growth and proliferation, it is fast emerging as a highly attractive biomarker for the imaging and treatment of human malignancies, including breast cancer. While multibranched gold nanoparticles (AuNPs) have emerged as a promising modality in the photothermal therapy (PTT) of cancers, some of the key challenges limiting their clinical translation lie in the need to develop reproducible and cost-effective synthetic methods as well as the selective accumulation of sufficient AuNPs at tumor sites. In this study, we report a simple and direct seed-mediated synthesis of monodispersed multibranched AuNPs using the catechol-containing LAT-1 ligands, L- and D-dopa, to confer active cancer targeting. This route obviates the need for additional conjugation with targeting moieties such as peptides or antibodies. Nanoflower-like AuNPs (AuNF) with diameters of approximately 46, 70, and 90 nm were obtained and were found to possess excellent colloidal stability and biocompatibility. A significantly higher intracellular accumulation of the L- and D-dopa functionalized AuNFs was observed in a panel of breast cancer cell lines (MCF-7, MDA-MB-231, MDA-MB-468, and MDA-MB-453) when compared to the nontargeting control AuNFs synthesized with dopamine and 4-ethylcatechol. Importantly, no significant difference in uptake between the targeting and nontargeting AuNFs was observed in a non-tumorigenic MCF-10A breast epithelial cell line, hence demonstrating tumor selectivity. For PTT of breast cancer, Ag⁺ was introduced during synthesis to obtain L-dopa functionalized nanourchin-like AuNPs (AuNUs) with strong near-infrared (NIR) absorbance. The L-dopa functionalized AuNUs mediated selective photothermal ablation of the triple negative MDA-MB-231 breast cancer cell line and sensitized the cells to the anticancer drugs cisplatin and docetaxel. This work brings forward an effective strategy for the facile preparation of cancer targeting multibranched AuNPs with potential for the in vivo PTT of breast cancer.

Gold nanoparticle-mediated photothermal therapy: applications and opportunities for multimodal cancer treatment

Photothermal therapy (PTT), in which nanoparticles embedded within tumors generate heat in response to exogenously applied laser light, has been well documented as an independent strategy for highly selective cancer treatment. Gold-based nanoparticles are the main mediators of PTT because they offer: (1) biocompatibility, (2) small diameters that enable tumor penetration upon systemic delivery, (3) simple gold-thiol bioconjugation chemistry for the attachment of desired molecules, (4) efficient light-to-heat conversion, and (5) the ability to be tuned to absorb near-infrared light, which penetrates tissue more deeply than other wavelengths of light. In addition to acting as a standalone therapy, gold nanoparticle-mediated PTT has recently been evaluated in combination with other therapies, such as chemotherapy, gene regulation, and immunotherapy, for enhanced anti-tumor effects. When delivered independently, the therapeutic success of molecular agents is hindered by premature degradation, insufficient tumor delivery, and off-target toxicity. PTT can overcome these limitations by enhancing tumor- or cell-specific delivery of these agents or by sensitizing cancer cells to these additional therapies. All together, these benefits can enhance the therapeutic success of both PTT and the secondary treatment while lowering the required doses of the individual agents, leading to fewer off-target effects. Given the benefits of combining gold nanoparticle-mediated PTT with other treatment strategies, many exciting opportunities for multimodal cancer treatment are emerging that will ultimately lead to improved patient outcomes. WIREs Nanomed Nanobiotechnol 2017, 9:e1449. doi: 10.1002/wnan.1449 For further resources related to this article, please visit the WIREs website.

Photothermal therapeutic application of gold nanorods-porphyrin-trastuzumab complexes in HER2-positive breast cancer

Gold nanorods are effective photothermal agents in diagnosis and treatment of cancer due to their specific near-infrared laser absorption. However, tumor photothermal therapy by nanorods alone is lack of targeting. Here, we described a novel nanocomplex made up of gold nanorods, porphyrin, and trastuzumab, called TGNs and investigated the TGN-mediated photothermal therapy as a potential alternative treatment of targeting HER2-positive breast cancers. By conjugating trastuzumab and porphyrin to the surface of gold nanorods, we have increased the targeting specificity and amplified the detecting effectiveness at the same time. TGN-mediated photothermal ablation by near-infrared laser led to a selective destruction of HER2-positive cancer cells and significantly inhibited tumor growth in mouse models bearing HER2 over-expressed breast cancer xenograft with less toxicity. Moreover, TGNs provided better therapeutic efficacy in comparison with the conventional molecule targeted therapy. Our current data suggest a highly promising future of TGNs for its therapeutic application in trastuzumab-resistant breast cancers.

Using Gold Nanoparticles To Disrupt the Tumor Microenvironment: An Emerging Therapeutic Strategy

Gold nanoparticles have received much attention recently as carriers for anticancer drugs and therapeutic oligonucleotides, but little research has investigated their potential to act as stand-alone therapeutics. Previous studies interrogating their short- and long-term systemic toxicity have found that although gold nanoparticles accumulate within and clear slowly from the liver and spleen, they do not appear to exert toxic effects in these organs. Interestingly, gold nanoparticles innately exhibit the ability to modulate the tumor microenvironment specifically by interfering with crosstalk between tumor cells and stromal cells. In this issue of ACS Nano, Mukherjee and colleagues demonstrate that bare gold nanoparticles can disturb crosstalk between pancreatic stellate cells and pancreatic cancer cells by modulating the cellular secretome to reduce the growth of desmoplastic tissue and inhibit tumor growth. In this Perspective, we highlight opportunities for anticancer targeting within the tumor microenvironment and discuss gold nanoparticles as potential mediators of microenvironment-targeted therapy.

Photothermal therapy improves the efficacy of a MEK inhibitor in neurofibromatosis type 1-associated malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive tumors with low survival rates and the leading cause of death in neurofibromatosis type 1 (NF1) patients under 40 years old. Surgical resection is the standard of care for MPNSTs, but is often incomplete and can generate loss of function, necessitating the development of novel treatment methods for this patient population. Here, we describe a novel combination therapy comprising MEK inhibition and nanoparticle-based photothermal therapy (PTT) for MPNSTs. MEK inhibitors block activity driven by Ras, an oncogene constitutively activated in NF1-associated MPNSTs, while PTT serves as a minimally invasive method to ablate cancer cells. Our rationale for combining these seemingly disparate techniques for MPNSTs is based on several reports demonstrating the efficacy of systemic chemotherapy with local PTT. We combine the MEK inhibitor, PD-0325901 (PD901), with Prussian blue nanoparticles (PBNPs) as PTT agents, to block MEK activity and simultaneously ablate MPNSTs. Our data demonstrate the synergistic effect of combining PD901 with PBNP-based PTT, which converge through the Ras pathway to generate apoptosis, necrosis, and decreased proliferation, thereby mitigating tumor growth and increasing survival of MPNST-bearing animals. Our results suggest the potential of this novel local-systemic combination “nanochemotherapy” for treating patients with MPNSTs.