Combinatorial photothermal and immuno cancer therapy using chitosan-coated hollow copper sulfide nanoparticles

Prussian blue nanoparticle-based antigenicity and adjuvanticity trigger robust antitumor immune responses against neuroblastoma

We describe the synthesis of CpG oligodeoxynucleotide-coated Prussian blue nanoparticles (CpG-PBNPs) that function as a nanoimmunotherapy for neuroblastoma, a common childhood cancer. These CpG-PBNPs increase the antigenicity and adjuvanticity of the treated tumors, ultimately driving robust antitumor immunity through a multi-pronged mechanism. CpG-PBNPs are synthesized using a facile layer-by-layer coating scheme resulting in nanoparticles that exhibit monodisperse size distributions and multiday stability without cytotoxicity. The strong intrinsic absorption of PBNPs in the CpG-PBNPs enables ablative photothermal therapy (CpG-PBNP-PTT) that triggers tumor cell death, as well as the release of tumor antigens to increase antigenicity. Simultaneously, the CpG coating functions as an exogenous molecular adjuvant that complements the endogenous adjuvants released by the CpG-PBNP-PTT (e.g. ATP, calreticulin, and HMGB1). In cell culture, coating NPs with CpG increases immunogenicity while maintaining the photothermal activity of PBNPs. When administered in a syngeneic, Neuro2a-based, murine model of neuroblastoma, CpG-PBNP-PTT results in complete tumor regression in a significantly higher proportion (70% at 60 days) of treated animals relative to controls. Furthermore, the long-term surviving, CpG-PBNP-PTT-treated animals reject Neuro2a rechallenge, suggesting that this therapy generates immunological memory. Our findings point to the importance of simultaneous cytotoxicity, antigenicity, and adjuvanticity to generate robust and persistent antitumor immune responses against neuroblastoma.

Multifunctional titanium phosphate nanoparticles for site-specific drug delivery and real-time therapeutic efficacy evaluation

Receptor-targeted delivery systems have been proposed as means of concentrating therapeutic agents to improve therapeutic effects on disease sites and reduce side effects on normal issues. Herein, we synthesized biocompatible folic acid (FA)-functionalized DHE-modified TiP (TiP-PAH-DHE-FA) nanoparticles as a drug delivery system that possessed high drug loading capability and enhanced folate-receptor-mediated cellular uptake. Moreover, it also allowed drug effect evaluation based on the real-time monitoring of the fluorescence intensity of HE molecules that are triggered by intercellular ROS. This acquired drug delivery system provided a novel platform to integrate efficient cell-specific drug delivery with real-time monitoring of therapeutic efficacy.

Fluorescence imaging guided CpG nanoparticles-loaded IR820-hydrogel for synergistic photothermal immunotherapy

As synergistic photothermal immunotherapy has developed as one of the most attractive strategies for cancer therapy, it is crucial to design an effective photothermal immunotherapy system to enhance the synergistic anti-tumor effect and reveal the essential role of each treatment. In this study, we designed CpG self-crosslinked nanoparticles-loaded IR820-conjugated hydrogel with dual self-fluorescence to exert the combined photothermal-immunotherapy. IR820-hydrogel can be effective for hyperthermia to eliminate the primary tumor based on its comprehensive coverage and generated photothermal-induced tumor antigens for assisted immunotherapy. CpG self-crosslinked nanoparticles improved the immune response of adjuvant against melanoma without extra nano-carriers. The synergistic photothermal immunotherapy was achieved by the merging of CpG self-crosslinked nanoparticles and IR820-hydrogel. A possible mechanism of combined antitumor effect was further revealed by analyzing immune cells including CD8 ⁺T cells, DCs, B cells, Treg and MDSC in tumor microenvironment. The specific antitumor immunity was provoked to remove the tumor residues and ultimately the combined treatment mode achieved more effective systemic therapeutic effect than either photothermal therapy or immunotherapy alone. Furthermore, self-fluorescent IR820-hydrogel and CpG nanoparticles exerted the imaging-guided combined photothermal-immunotherapy by the dual fluorescence imaging method without additional fluorescent labeling. This visible combined photothermal-immunotherapy offers a potential for precise cancer treatment.

Using near-infrared enhanced thermozyme and scFv dual-conjugated Au nanorods for detection and targeted photothermal treatment of Alzheimer's disease

Investigation of targeting inhibitors of Aβ aggregation, heme-Aβ peroxidase-like activity and efficient detectors of Aβ aggregation, are of therapeutic value and diagnostics significance for the treatment of Alzheimer's disease (AD). Due to the complex pathogenesis of AD, theranostics treatment with multiple functions are necessary. Herein we constructed the NIR absorption property of gold nanorods (GNRs) loaded with single chain variable fragment (scFv) 12B4 and thermophilic acylpeptide hydrolase (APH) ST0779 as a smart theranostic complex (GNRs-APH-scFv, GAS), which possesses both rapid detection of Aβ aggregates and NIR photothermal treatment that effectively disassembles Aβ aggregates and inhibits Aβ-mediated toxicity.

Methods: We screened targeting anti-Aβ scFv 12B4 and thermophilic acylpeptide hydrolase as amyloid-degrading enzyme, synthesized GAS gold nanorods complex. The GAS was evalued by Aβ inhibition and disaggregation assays, Aβ detection assays, Aβ mediated toxicity assays in vitro. In vivo, delaying Aβ-induced paralysis in AD model of Caenorhabditis elegans was also tested by GAS.

Results: In vitro, GAS has a synergistic effect to inhibit and disassociate Aβ aggregates, in addition to decrease heme-Aβ peroxidase-like activity. In cultured cells, treatment with GAS reduces Aβ-induced cytotoxicity, while also delaying Aβ-mediated paralysis in CL4176 C.elegans model of AD. Furthermore, the photothermal effect of the GAS upon NIR laser irradiation not only helps disassociate the Aβ aggregates but also boosts APH activity to clear Aβ. The GAS, as a targeting detector and inhibitor, allows real-time detection of Aβ aggregates.

Conclusion: These results firstly highlight the combination of scFv, APH and nanoparticles to be theranostic AD drugs. Taken together, our strategy provides a new thought into the design of smart compounds for use as efficiently therapeutic and preventive agents against AD. Moreover, our design provides broad prospects of biomedical strategy for further theranostics application in those diseases caused by abnormal protein.

Microfluidics-Prepared Uniform Conjugated Polymer Nanoparticles for Photo-Triggered Immune Microenvironment Modulation and Cancer Therapy

Photothermal therapy (PTT) has shown great promise to spatiotemporally ablate cancer cells, and further understanding of the immune system response to PTT treatment would contribute to improvement in therapeutic outcomes. Herein, we utilize microfluidic technology to prepare biocompatible conjugated polymer nanoparticles (CP NPs) as PTT agents and assess the immune response triggered by CP-based PTT treatment in vitro and in vivo. Through careful control of the antisolvent, CP NPs with a uniform diameter of 52 nm were obtained. The c-RGD-functionalized CP NPs exhibit high photothermal conversion efficiency, inducing effective cancer cell death under an 808 nm laser illumination. Using macrophage cells as the model, CP NPs demonstrate effective activation of proinflammatory immune response. Furthermore, in tumor-bearing mice model, a single round of CP NP-assisted PTT could efficiently induce antitumor immunity activation and ultimately inhibit tumor growth. The study provides detailed understanding of both microfluidic technology for CP NP fabrication and photothermal-triggered antitumor immune responses.

Copper sulfide: An emerging adaptable nanoplatform in cancer theranostics

Copper sulfide nanoparticles (CuS NPs), emerging nanoplatforms with dual diagnostic and therapeutic applications, are being actively investigated in this era of "war on cancer" owing to their versatility and adaptability. This article discusses the pros and cons of using CuS NPs in diagnostics, therapeutics, and theranostics. The first section introduces CuS NPs and discusses the features that render them more advantageous than other established nanoplatforms in cancer management. Subsequent sections include specific in vitro and in vivo results of different studies showing the potential of CuS NPs as nanoplatforms. Methods used for visualization (photoacoustic imaging and magnetic resonance imaging) of CuS NPs and treatment (phototherapy and combinatorial therapy) have also been discussed. Furthermore, the challenges and opportunities associated with using CuS NPs have been elucidated. Further investigations on CuS NPs are required to translate it for clinical applications.

Highly efficient cascading synergy of cancer photo-immunotherapy enabled by engineered graphene quantum dots/photosensitizer/CpG oligonucleotides hybrid nanotheranostics

Currently, photoimmunotherapy based on a theranostic nanoplatform emerges as a promising modality in advanced cancer therapy. In this study, a new type of versatile nanoassemblies (denoted as PC@GCpD(Gd)) was rationally designed by integrating the polydopamine stabilized graphene quantum dots (GQD)-photosensitizer nanocomposites (denoted as GCpD), immunostimulatory polycationic polymer/CpG oligodeoxynucleotide (CpG ODN) nanoparticles (denoted as PC) and Gd³⁺/Cy3 imaging probes for dual magnetic resonance/fluorescence imaging-guided photoimmunotherapy. PC@GCpD(Gd) effectively killed the tumor cells through the amplified photothermal and photodynamic effects mediated by GCpD, and contemporaneously delivered CpG ODN to the targeted endosomal Toll-like receptor 9 (TLR9) to continuously stimulate the secretion of proinflammatory cytokines and the maturation of dendritic cells, thereby resulting in the activation and infiltration of T lymphocytes. As a result, PC@GCpD(Gd) achieved robust inhibition efficiency to almost completely suppress the EMT6 murine mammary cancer model under laser irradiation, implying the superior synergy of combined photoimmunotherapy. Moreover, the in vivo delivery and biodistribution of PC@GCpD(Gd) could be tracked using the high-quality bimodal magnetic resonance imaging/fluorescence imaging. This study highlighted the potent prospect of hybrid PC@GCpD(Gd) nanoassemblies for precise cancer photoimmunotherapy with a cascading effect.

Photothermally activatable PDA immune nanomedicine combined with PD-L1 checkpoint blockade for antimetastatic cancer photoimmunotherapy

Photothermal therapy (PTT) has shown promising potential and bright prospects in damaging primary tumors; however, it is limited to metastatic and recrudescent tumors as PTT requires straightforward light irradiation. Moreover, metastatic and recrudescent tumor immunosuppression due to host T-cell antitumor activity is dramatically impeded because of programmed cell death 1 ligand (PD-L1) and programmed cell death receptor 1 (PD-1) pathways and immune checkpoint blockade (ICB) therapy. In this work, we demonstrate that PTT combined with ICB could not only eliminate primary tumors, but also prevent tumor metastasis to the lungs/liver. In particular, we have designed immunoadjuvant nanomedicine carriers on the basis of polydopamine (PDA) simultaneously loaded with resiquimod (R848)-a kind of toll-like receptor 7 (TLR7) agonist-and carbon dots (CDs)-a fluorescent agent. This nanomedicine is defined as PDA-PEG-R848-CD nanoparticle (NP). The multitasking PDA-PEG-R848-CD NPs can destroy 4T1 breast tumors by PTT under near-infrared laser irradiation in addition to generating tumor-associated antigens. Moreover, the PTT effect triggered the release of R848, thereby inducing a strong antitumor immune response. Meanwhile, this synergistic therapy also shows the abscopal effects by completely inhibiting the growth of untreated distant tumors by effectively triggering the tumors infiltrated by CD3/CD8. Such findings suggest that PDA-PEG-R848-CD NPs could significantly potentiate the systemic therapeutic efficiency of PD-L1 checkpoint blockade therapy by activating both innate and adaptive immune systems in the body.

Addressing barriers to effective cancer immunotherapy with nanotechnology: achievements, challenges, and roadmap to the next generation of nanoimmunotherapeutics

Cancer is a complex systemic disorder that affects many organs and tissues and arises from the altered function of multiple cellular and molecular mechanisms. One of the systems malfunctioning in cancer is the immune system. Restoring and improving the ability of the immune system to effectively recognize and eradicate cancer is the main focus of immunotherapy, a topic which has garnered recent and significant interest. The initial excitement about immunotherapy, however, has been challenged by its limited efficacy in certain patient populations and the development of adverse effects such as therapeutic resistance and autoimmunity. At the same time, a number of advances in the field of nanotechnology have sought to address the challenges faced by modern immunotherapeutics and allow these therapeutic strategies to realize their full potential. This endeavour requires an understanding of not only the immunological barriers in cancer but also the mechanisms by which modern technologies and immunotherapeutics modulate the function of the immune system. Herein, we summarize the major barriers relevant to cancer immunotherapy and review current progress in addressing these obstacles using various approaches and clinically approved therapies. We then discuss the remaining challenges and how they can be addressed by nanotechnology. We lay out translational considerations relevant to the therapies described and propose a framework for the development of next-generation nanotechnology-enabled immunotherapies.

Nanotechnology-based photoimmunological therapies for cancer

Phototherapy is a non-invasive or minimally invasive therapeutic strategy. Immunotherapy uses different immunological approaches, such as antibodies, vaccines, immunoadjuvants, and cytokines to stimulate the host immune system to fight against diseases. In cancer treatment, phototherapy not only destroys tumor cells, but also induces immunogenic tumor cell death to initiate a systemic anti-tumor immune response. When combined with immunotherapy, the effectiveness of phototherapy can be enhanced. Because of their special physical, chemical, and sometimes immunological properties, nanomaterials have also been used to enhance phototherapy. In this article, we review the recent progress in nanotechnology-based phototherapy, including nano-photothermal therapy, nano-photochemical therapy, and nano-photoimmunological therapy in cancer treatment. Specifically, we focus on the immunological responses induced by nano-phototherapies.

Recent Advances in Polymeric Nanomedicines for Cancer Immunotherapy

Immunotherapy has emerged as a promising approach to treat cancer, since it facilitates eradication of cancer by enhancing innate and/or adaptive immunity without using cytotoxic drugs. Of the immunotherapeutic approaches, significant clinical potentials are shown in cancer vaccination, immune checkpoint therapy, and adoptive cell transfer. Nevertheless, conventional immunotherapies often involve immune-related adverse effects, such as liver dysfunction, hypophysitis, type I diabetes, and neuropathy. In an attempt to address these issues, polymeric nanomedicines are extensively investigated in recent years. In this review, recent advances in polymeric nanomedicines for cancer immunotherapy are highlighted and thoroughly discussed in terms of 1) antigen presentation, 2) activation of antigen-presenting cells and T cells, and 3) promotion of effector cells. Also, the future perspectives to develop ideal nanomedicines for cancer immunotherapy are provided.

Advanced nanotechnology: An arsenal to enhance immunotherapy in fighting cancer

Cancer remains a major disease process with considerable healthcare and socioeconomic impact worldwide. Unfortunately, standard treatments using chemotherapy often do not effectively control cancer progression or prevent relapse. Over the past decades, the development of targeted therapies has substantially improved outcomes. Recently, immunotherapy has emerged as a new alternative for more effective cancer treatment and may even bring hope of a cure. Cancer immunotherapy functions by reinforcing a patient's immune defense system to fight the disease. Clinically, promising immunotherapy approaches have, however, been limited by unpredictable response and strong adverse effects. A drug delivery system (DDS) that effectively targets tumor and reduces drug exposure to normal tissue would mitigate these limitations. In this regard, nanotechnology has been intensively studied as a DDS for targeting tumors with various oncologic drugs. Several have resulted in improved treatment and outcome. Research has shown that nanoparticle drug delivery technologies can also be applied to immunotherapy. In this review, the current state of nanotechnology will be discussed. Because most cancer immunotherapies approved in recent years are protein drugs, this article will focus on a micellar nanocomplex (MNC) technology, a DDS platform especially suited for targeted delivery of these therapeutics to solid tumors.

Hypoxia-Triggered Transforming Immunomodulator for Cancer Immunotherapy via Photodynamically Enhanced Antigen Presentation of Dendritic Cell

A key factor for successful cancer immunotherapy (CIT) is the extent of antigen presentation by dendritic cells (DCs) that phagocytize tumor-associated antigens (TAA) in the tumor site and migrate to tumor draining lymph nodes (TDLN) for the activation of T cells. Although various types of adjuvant delivery have been studied to enhance the activity of the DCs, poor delivery efficiency and depleted population of tumor infiltrating DCs have limited the efficacy of CIT. Herein, we report a hypoxia-responsive mesoporous silica nanocarrier (denoted as CAGE) for an enhanced CIT assisted by photodynamic therapy (PDT). In this study, CAGE was designed as a hypoxia-responsive transforming carrier to improve the intracellular uptake of nanocarriers and the delivery of adjuvants to DCs. Furthermore, PDT was exploited for the generation of immunogenic debris and recruitment of DCs in a tumor site, followed by enhanced antigen presentation. Finally, a significant inhibition of tumor growth was observed in vivo, signifying that the PDT would be a promising solution for DC-based immunotherapy.

Nanoparticle-Mediated Immunogenic Cell Death Enables and Potentiates Cancer Immunotherapy

Cancer immunotherapies that train or stimulate the inherent immunological systems to recognize, attack, and eradicate tumor cells with minimal damage to healthy cells have demonstrated promising clinical responses in recent years. However, most of these immunotherapeutic strategies only benefit a small subset of patients and cause systemic autoimmune side effects in some patients. Immunogenic cell death (ICD)-inducing modalities not only directly kill cancer cells but also induce antitumor immune responses against a broad spectrum of solid tumors. Such strategies for generating vaccine-like functions could be used to stimulate a "cold" tumor microenvironment to become an immunogenic, "hot" tumor microenvironment, working in synergy with immunotherapies to increase patient response rates and lead to successful treatment outcomes. This Minireview will focus on nanoparticle-based treatment modalities that can induce and enhance ICD to potentiate cancer immunotherapy.

Phase-Change Material Packaged within Hollow Copper Sulfide Nanoparticles Carrying Doxorubicin and Chlorin e6 for Fluorescence-Guided Trimodal Therapy of Cancer

Environmental stimuli, including pH, light, and temperature, have been utilized for activating controlled drug delivery to achieve efficient antitumor therapeutics while minimizing undesirable side effects. In this study, a multifunctional nanoplatform based on hollow mesoporous copper sulfide nanoparticles (H-CuS NPs) was developed by loading the interior cavity of the NPs with a drug-loaded phase-change material (PCM, 1-tetradecanol). Doxorubicin (DOX) and chlorin e6 (Ce6) were selected as the model chemotherapeutic drug and photosensitizer, respectively, which were encapsulated in H-CuS NPs via the PCM to form H-CuS@PCM/DOX/Ce6 (HPDC) NPs. When exposed to near infrared laser irradiation, this nanocomplex could produce a strong photothermic effect and thus induce the controlled release of DOX and Ce6 from the melting PCM. Subsequently, the DOX-mediated chemotherapeutic effect and Ce6-mediated photodynamic effect further contributed to enhanced tumor eradication. The efficacy of this multimodal cancer treatment combining chemo-, photothermal, and photodynamic therapies was systematically evaluated both in vitro and in vivo using a 4T1 mouse mammary tumor cell line and a mouse model bearing breast cancer. Moreover, this nanoplatform exhibited minimal systemic toxicity and good hemocompatibility and may provide an effective strategy for the delivery of multiple therapeutic agents and application of multimodal cancer treatments.

Recent advances in nanomaterial-based synergistic combination cancer immunotherapy

This review aims to summarize various synergistic combination cancer immunotherapy strategies based on nanomaterials.

Local biomaterials-assisted cancer immunotherapy to trigger systemic antitumor responses

Cancer immunotherapy by educating or stimulating patients’ own immune systems to attack cancer cells has demonstrated promising therapeutic responses in the clinic.

Electrodeposition of nanowires of a high copper content thiourea precursor of copper sulfide

Copper thiourea complexes are an important material class for application as a precursor of copper sulfide nanocrystals with potential use in solar cells, optoelectronics, medicine, etc. They represent a type of single source precursor, comprising both copper and sulfur in one chemical compound, whose tunable stoichiometry and morphology enable control of the quality and properties of the synthesized copper sulfide nanocrystals. Here, we present a template free electrochemical route to prepare nanowires of copper thiourea (tu) chloride hemihydrate ([Cu(tu)]Cl·½H₂O) by pulse deposition. We proposed the model of the growth of nanowires. We also demonstrate complete transformation from the precursor to copper sulfide nanowire by heating it to 180 °C that involves 20% volume loss due to the decomposition of organic constituents; the obtained nanowires have around 38% covellite (CuS) and 62% digenite (Cu_1.8S) phases. Electrochemistry offers the advantage of spatially selected deposition e.g. in the active regions of a device.

In this study we reported the pulsed electrodeposition technique of copper thiourea complex nanowires which is an important material class for application as a precursor of copper sulfide nanocrystals with potential use in solar cells, optoelectronics, medicine, etc.

Recent development in biodegradable nanovehicle delivery system-assisted immunotherapy

A schematic illustration of BNDS biodegradation and release antigen delivery for assisting immunotherapy.

A multifunctional near-infrared laser-triggered drug delivery system using folic acid conjugated chitosan oligosaccharide encapsulated gold nanorods for targeted chemo-photothermal therapy

FA–COS–TGA–GNRs–DOX have been successfully designed as a drug delivery system for chemo-photothermal combination therapy.

Nanoparticle-Mediated Remodeling of the Tumor Microenvironment to Enhance Immunotherapy

Nanoscience has long been lauded as a method through which tumor-associated barriers could be overcome. As successful as cancer immunotherapy has been, limitations associated with the tumor microenvironment or side effects of systemic treatment have become more apparent. In this Review, we seek to lay out the therapeutic challenges associated with the tumor microenvironment and the ways in which nanoscience is being applied to remodel the tumor microenvironment and increase the susceptibility of many cancer types to immunotherapy. We detail the nanomedicines on the cutting edge of cancer immunotherapy and how their interactions with the tumor microenvironment make them more effective than systemically administered immunotherapies.

Rational combination immunotherapeutic approaches for effective cancer treatment

Immunotherapy is an important mode of cancer treatment. Over the past decades, immunotherapy has improved the clinical outcome for cancer patients. However, in many cases, mutations in cancer cells, lack of selectivity, insufficiency of tumor-reactive T cells, and host immunosuppression limit the clinical benefit of immunotherapy. Combination approaches in immunotherapy may overcome these obstacles. Accumulating evidence demonstrates that combination immunotherapy is the future of cancer treatment. However, designing safe and rational combinations of immunotherapy with other treatment modalities is critical. This review will discuss the optimal immunotherapy-based combinations mainly with respect to the mechanisms of action of individual therapeutic agents that target multiple steps in evasion and progression of tumor.

Self-assembled CpG oligodeoxynucleotides conjugated hollow gold nanospheres to enhance cancer-associated immunostimulation

To realize efficiently cellular uptake and enhance the immunostimulation, thiolated cytosine-phosphate-guanine (CpG) oligodeoxynucleotides (ODNs) were self-assembled on hollow gold nanospheres (HGNs) to form CpG-HGNs. The cellular uptake of CpG-HGNs in immune cells was studied in RAW 264.7 cells. Due to the enhanced delivery efficiency, CpG-HGNs exhibited a higher immune stimulatory activity compared with CpG ODNs, resulting in a dramatically enhanced secretion of proinflammatory cytokines. In addition, CpG-HGNs showed low cytotoxicity in RAW 264.7 cells. CpG-HGNs could potentially realize synergistic photothermal therapy and immunotherapy in vivo.

Hypoxia-triggered single molecule probe for high-contrast NIR II/PA tumor imaging and robust photothermal therapy

Hypoxia is a common characteristic of solid tumors. This important feature is associated with resistance to radio-chemotherapy, which results in poor prognosis and probability of tumor recurrence. Taking advantage of background-free NIR II fluorescence imaging and deeper-penetrating photoacoustic (PA) imaging, we developed a hypoxia-triggered and nitroreductase (NTR) enzyme-responsive single molecule probe for high-contrast NIR II/PA tumor imaging and hypoxia-activated photothermal therapy (PTT), which will overcome cellular resistance during hypoxia. Methods: The single molecule probe IR1048-MZ was synthesized by conjugating a nitro imidazole group as a specific hypoxia trigger with an IR-1048 dye as a NIR II/PA signal reporter. We investigated the NIR II fluorescence, NIR absorbance and photothermal effect in different hypoxia conditions in vitro, and performed NIR II/PA tumor imaging and hypoxia-activated photothermal therapy in mice. Results: This versatile molecular probe IR1048-MZ not only realized high-contrast tumor visualization with a clear boundary by NIR II fluorescence imaging, but also afforded deep-tissue penetration at the centimeter level by 3D PA imaging. Moreover, after being activated by NTR that is overexpressed in hypoxic tumors, the probe exhibited a significant photothermal effect for curative tumor ablation with no recurrence. Conclusions: We have developed the first hypoxia-triggered and NTR enzyme-responsive single molecule probe for high-contrast NIR II/PA tumor imaging and hypoxia-activated photothermal therapy. By tracing the activity of NTR, IR1048-MZ may be a promising contrast agent and theranostic formulation for other hypoxia-related diseases (such as cancer, inflammation, stroke, and cardiac ischemia).

Unique Photochemo-Immuno-Nanoplatform against Orthotopic Xenograft Oral Cancer and Metastatic Syngeneic Breast Cancer

Sophisticated self-assembly may endow materials with a variety of unique functions that are highly desirable for therapeutic nanoplatform. Herein, we report the coassembly of two structurally defined telodendrimers, each comprised of hydrophilic linear PEG and hydrophobic cholic acid cluster as a basic amphiphilic molecular subunit. One telodendrimer has four added indocyanine green derivatives, leading to excellent photothermal properties; the other telodendrimer has four sulfhydryl groups designed for efficient intersubunit cross-linking, contributing to superior stability during circulation. The coassembled nanoparticle (CPCI-NP) possesses superior photothermal conversion efficiency as well as efficient encapsulation and controlled release of cytotoxic molecules and immunomodulatory agents. CPCI-NP loaded with doxorubicin has proven to be a highly efficacious combination photothermal/chemotherapeutic nanoplatform against orthotopic OSC-3 oral cancer xenograft model. When loaded with imiquimod, a potent small molecule immunostimulant, CPCI-NP is found to be highly effective against 4T1 syngeneic murine breast cancer model, particularly when photothermal/immuno-therapy is given in combination with PD-1 checkpoint blockade antibody. Such triple therapy not only eradicates the light-irradiated primary tumors, but also activates systemic antitumor immunoactivity, causing tumor death at light-unexposed distant tumor sites. This coassembled multifunctional, versatile, and easily scalable photothermal immuno-nanoplatform shows great promise for clinical translation.

Cetuximab-modified CuS nanoparticles integrating near-infrared-II-responsive photothermal therapy and anti-vessel treatment

BACKGROUND

Photothermal therapy (PTT) has received extensive attention owing to its non-invasive nature and highly therapeutic outcomes. PTT agents and near-infrared (NIR) laser are essential elements in PTT. However, most PTT agents are composed of heavy metals, characterized by serious cytotoxicity and side effects, and NIR irradiation often damages normal tissue owing to the high dose, thus limiting the clinical application of PTT.

PURPOSE

In this regard, exploring new perspectives enabling more PTT agents to be enriched into the tumor and NIR laser irradiation decay in PTT is vital.

METHODS

In this study, cetuximab (Ab), an anti-angiogenic antibody which targets the EGFR, was modified on CuS NPs (CuS-Ab NPs) to improve the aggregation of CuS NPs in the tumor.

RESULTS

The cellular uptake data and the biodistribution results showed comparable accumulation of CuS-Ab NPs in tumor, thus decreasing the cytotoxicity and side effects in normal tissues. More importantly, the modification of Ab in CuS-Ab NPs impressively inhibited the formation and progression of tumor vessels, as demonstrated by immunohistochemistry staining. The introduction of anti-vessel treatment requires CuS-Ab NPs to provide weak PTT, which means that a small amount of laser energy is required, inevitably causing negligible damage to normal tissue.

CONCLUSION

Therefore, our tailor-made CuS-Ab NPs have promising potential in clinical applications.

Artificially controlled degradable nanoparticles for contrast switch MRI and programmed cancer therapy

Background

Utilizing the permeability enhancement and irreversible biomolecule denaturation caused by hyperthermia, photothermal-chemo synergistic therapy has shown great potential in clinical cancer treatment.

Purpose

The objective of this study was to provide a novel controlled drug release method to improve the efficiency of photothermal-chemo synergistic therapy.

Patients and methods

HCT116 tumor-bearing mice were selected as modal for the study of cancer theranostics efficiency. The T2 to T1 magnetic resonance imaging contrast switch was studied in vivo. Analyses of the tumor growth of mice were carried out to evaluate the tumor therapy efficiency.

Results

We developed novel artificially controlled degradable Co₃O₄ nanoparticles and explored their potential in drug delivery/release. In the presence of ascorbic acid (AA), the designed nanomaterials can be degraded via a redox process and hence release the loaded drugs. Importantly, the AA, in the lack of l-gulonolactone oxidase, cannot be synthesized in the body of typical mammal including human, which suggested that the degradation process can be controlled artificially. Moreover, the obtained nanoparticles have outstanding photothermal conversion efficiency and their degradation can also result in an magnetic resonance imaging contrast enhancement switch from T₂ to T₁, which benefits the cancer theranostics.

Conclusion

Our results illustrated that the artificially controlled degradable nanoparticles can serve as an alternative candidate for controllable drug release as well as a platform for highly efficient photothermal-chemo synergistic cancer theranostics.

Quaternized chitosan-stabilized copper sulfide nanoparticles for cancer therapy

In this study, we report a smart and green strategy to synthesize copper sulfide nanoparticles (CuS-NPs) for clinically translatable cancer treatment. For the first time, the preparation of CuS-NPs was developed by taking advantage of the copper-amine complex as the copper source and sodium sulfide as the sulfide source, in which the quaternized chitosan (QCS) was used as a biotemplate and stabilizing agent. The obtained QCS/CuS-NPs composites (CuS@QCS-NPs) were spherical and stable with an average diameter of 5.6 nm, and showed strong NIR absorbance for photothermal conversion. Moreover, in vitro and in vivo cancer theranostic capability of CuS@QCS-NPs without any biomodification was evaluated. The result reveals that after intratumoral (i.t.) injection of CuS@QCS-NPs with NIR laser irradiation (808 nm, 1.5 W/cm², 5 min), the 4T1 mammary tumor growth could be effectively suppressed comparing with the other control groups, and there was no obvious lethal toxicity to liver function, kidney function, and vital organs. Such QCS-stabilized CuS-NPs may provide an alternative for clinical application of CuS-based photothermal therapy.

Sacrificial template-based synthetic approach of polypyrrole hollow fibers for photothermal therapy

In the present work, polypyrrole hollow fibers (PPy-HFs) were fabricated by sacrificial removal of soft templates of electrospun polycaprolactone (PCL) fibers with polypyrrole (PPy) coating through chemical polymerization of pyrrole monomer. Different physicochemical properties of as-fabricated PPy-HFs were then studied by Field emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), Fourier transform infra-red (FT-IR) spectroscopy, Differential scanning calorimetry/Thermogravimetric analysis (DSC/TGA), and X-ray photoelectron spectroscopy (XPS). The photothermal activity of PPy-HF was studied by irradiating 808-nm near infra-red (NIR) light under different power values with various concentrations of PPy-HFs dispersed in phosphate buffer solution (PBS, pH 7.4). These PPy-HFs exhibited enhanced photothermal performance compared with polypyrrole nanoparticles (PPy-NPs). Furthermore, these PPy-HFs showed photothermal effect that was laser-power- and concentration-dependent. The photothermal toxicity of the resulting nanofiber was evaluated using cell counting kit-8 (CCK-8) and live and dead cell assays. Results showed that these PPy-HFs were more effective in killing cancer cells under NIR irradiation. In contrast, hollow-fiber showed no cytotoxicity without NIR exposure. Among different nanofiber formulations, PPy-160 exhibited the highest photothermal toxicity. It could be explained by its enhanced photothermal performance compared to other specimens. The resulting PPy-HFs showed superior drug-loading capacity to PPy-NPs. This might be attributed to adequate binding of the drug into both luminal and abluminal hollow-fiber surfaces. Fabrication of this substrate type opens a promising new avenue for architectural design of biocompatible organic polymer for biomedical field.

Immune lipoprotein nanostructures inspired relay drug delivery for amplifying antitumor efficiency

Chemo-immunotherapy represents an appealing approach to improving cancer treatment. Simultaneously administrating chemotherapeutics with immunoadjuvants can elicit potent tumor death and immune responses. Herein, high density lipoprotein (HDL) inspired immune lipoprotein was proposed for relay drug delivery and amplifying antitumor therapy. Lipophilic AS1411 aptamer-immunoadjuvant CpG fused sequences (Apt-CpG-DSPE) were conjugated to facilitate decoration onto HDLs; and doxorubicin (Dox) was successively intercalated into the consecutive base pairs of Apt-CpG to complete immune HDL nanodrug imHDL/Apt-CpG-Dox. For relay drug delivery, imHDL/Apt-CpG-Dox underwent site-specific structure collapse in tumor intercellular substances inspired from HDL biofunctions (sequential module I); subsequently, dissociated Apt-CpG-Dox was endocytosed into tumor cells mediated by the recognition of AS1411 and nucleolin (sequential module II), translocating Dox to nucleus and enabling tumor ablation and antigens release. The liberated CpG motif further evoked antigen recognition, induced vast secretion of pro-inflammatory cytokines and potentiated host antitumor immunity. Our studies demonstrated that HDL biomimetic platform based relay drug delivery strategy outperformed the monotherapy counterparts in malignant tumor models, eventually generating an augmented antitumor efficacy.

Folate-receptor-targeted laser-activable poly(lactide-co-glycolic acid) nanoparticles loaded with paclitaxel/indocyanine green for photoacoustic/ultrasound imaging and chemo/photothermal therapy

BACKGROUND

Cancer is one of the most serious threats to human health. Precision medicine is an innovative approach to treatment, as part of which theranostic nanomedicine has been studied extensively. However, the required biocompatibility and substantial cost for the approval of nanomedicines hinder their clinical translation.

PURPOSE

We designed a novel type of theranostic nanoparticle (NP) folate-receptor-targeted laser-activatable poly(lactide-co-glycolic acid) (PLGA) NPs loaded with paclitaxel (Ptx)/indo-cyanine green (ICG)-folic acid-polyethylene glycol (PEG)-PLGA-Ptx@ICG-perfluorohexane (Pfh)- using safe and approved materials and drugs, which would facilitate clinical translation. With laser irradiation, highly efficient photothermal therapy can be achieved. Additionally, targeted NPs can be activated by near-infrared laser irradiation at a specific region, which leads to the sharp release of Ptx at areas of high folate-receptor expression and ensures a higher Ptx concentration within the tumor region, thereby leading to chemo/photothermal synergistic antitumor efficacy. Meanwhile, the NPs can be used as a dual-modality contrast agent for photoacoustic and ultrasound imaging.

MATERIALS AND METHODS

FA-PEG-PLGA-Ptx@ICG-Pfh NPs were prepared by sonification method and characterized for physicochemical properties. Cytotoxicity and in vivo biocompatibility were evaluated respectively by CCK8 assay and blood analysis. NPs as dual-modality contrast agents were evaluated by photoacoustic/ultrasound imaging system in vitro and in vivo. In vitro anticancer effect and in vivo anticancer therapy was evaluated by CCK8 assay and MDA-MB231 tumor-bearing mice model.

RESULTS

FA-PEG-PLGA-Ptx@ICG-Pfh NPs were in the size of 308±5.82 nm with negative zeta potential and showed excellent photothermal effect. The NPs could be triggered sharp release of Ptx by laser irradiation, and showed the good biocompatibility in vitro and in vivo. Through photoacoustic/ultrasound imaging, the NPs showed an excellent ability as dual-modality contrast agents in vitro and in vivo. FA-PEG-PLGA-Ptx@ICG-Pfh NPs with laser irradiation showed the best anticancer efficacy in vitro and in vivo.

CONCLUSION

Such a biocompatible and novel theranostic NP is expected to integrate dual-modality imaging with improved therapeutic efficacy and provide a promising paradigm for cancer therapy.

Therapeutic applications of iron oxide based nanoparticles in cancer: basic concepts and recent advances

Nanotechnology has introduced new techniques and phototherapy approaches to fabricate and utilize nanoparticles for cancer therapy. These phototherapy approaches, such as photothermal therapy (PTT) and photodynamic therapy (PDT), hold great promise to overcome the limitations of traditional treatment methods. In phototherapy, magnetic iron oxide nanoparticles (IONPs) are of paramount importance due to their wide range of biomedical applications. This review discusses the basic concepts, various therapy approaches (PTT, PDT, magnetic hyperthermia therapy (MHT), chemotherapy and immunotherapy), intrinsic properties, and mechanisms of cell death of IONPs; it also provides a brief overview of recent developments in IONPs, with focus on their therapeutic applications. Much attention is devoted to elaborating the various parameters, intracellular behaviors and limitations of MHT. Bimodal therapies which act alone or in combination with other modalities are also discussed. The review highlights some limitations in the explored research areas and suggests future directions to overcome these limitations.

Cleavable and thermo-responsive hybrid nanoparticles for on-demand drug delivery

By combining the photothermal ability of copper sulphide nanoparticles (NPs) upon excitation with Near Infrared (NIR) Light and the thermo-responsive properties of the homemade oligo (ethylene glycol) methyl ether methacrylate copolymer we have obtained fragmentable nanocomposites able to release a carried drug on-demand after NIR-light triggering. A complete physico-chemical characterization of the resulting nanoparticles has been carried out and their degradation assessed at different temperatures. Herein, we have also evaluated the drug loading capacity of those nanoparticles and the temperature dependence in their drug release kinetics using bupivacaine hydrochloride as a model drug. For those hybrid nanoparticles, subcytotoxic doses on four different cell lines and their potential interference in cell metabolism, induction of apoptosis, and cell cycle have been evaluated by Alamar Blue fluorometry and flow cytometry.

Enhanced Intracellular Ca2+ Nanogenerator for Tumor-Specific Synergistic Therapy via Disruption of Mitochondrial Ca2+ Homeostasis and Photothermal Therapy

Breast cancer therapy has always been a hard but urgent issue. Disruption of mitochondrial Ca2+ homeostasis has been reported as an effective antitumor strategy, while how to contribute to mitochondrial Ca2+ overload effectively is a critical issue. To solve this issue, we designed and engineered a dual enhanced Ca2+ nanogenerator (DECaNG), which can induce elevation of intracellular Ca2+ through the following three ways: Calcium phosphate (CaP)-doped hollow mesoporous copper sulfide was the basic Ca2+ nanogenerator to generate Ca2+ directly and persistently in the lysosomes (low pH). Near-infrared light radiation (NIR, such as 808 nm laser) can accelerate Ca2+ generation from the basic Ca2+ nanogenerator by disturbing the crystal lattice of hollow mesoporous copper sulfide via NIR-induced heat. Curcumin can facilitate Ca2+ release from the endoplasmic reticulum to cytoplasm and inhibit expelling of Ca2+ in cytoplasm through the cytoplasmic membrane. The in vitro study showed that DECaNG could produce a large amount of Ca2+ directly and persistently to flow to mitochondria, leading to upregulation of Caspase-3, cytochrome c, and downregulation of Bcl-2 and ATP followed by cell apoptosis. In addition, DECaNG had an outstanding photothermal effect. Interestingly, it was found that DECaNG exerted a stronger photothermal effect at lower pH due to the super small nanoparticles effect, thus enhancing photothermal therapy. In the in vivo study, the nanoplatform had good tumor targeting and treatment efficacy via a combination of disruption of mitochondrial Ca2+ homeostasis and photothermal therapy. The metabolism of CaNG was sped up through disintegration of CaNG into smaller nanoparticles, reducing the retention time of the nanoplatform in vivo. Therefore, DECaNG can be a promising drug delivery system for breast cancer therapy.

Noninvasive photothermal cancer therapy nanoplatforms via integrating nanomaterials and functional polymers

In the cutting-edge field of cancer therapy, noninvasive photothermal therapy (PTT) has received great attention because it is considered to overcome the drawbacks of conventional surgery, radiotherapy and chemotherapy of severe body injuries and side effects on the immune system. The construction of PTT therapeutic and theranostic nanoplatforms is the key issue in achieving tumor targeting, imaging and therapy in a synergetic manner. In this review, we focus on the recent advances in constructing PTT therapeutic and theranostic nanoplatforms by integrating nanomaterials and functional polymers. The noninvasive photothermal cancer therapy mechanism and achievement strategies of PTT therapeutic and theranostic nanoplatforms are presented as well as the innovative construction strategies and perspectives for the future. Owing to their high tumor ablation efficiency, biological availability and low- or non-toxicity, PTT therapeutic and theranostic nanoplatforms are promising and emerging in medicine and clinical applications.

Recent Progress in Metal-Based Nanoparticles Mediated Photodynamic Therapy

Photodynamic therapy (PDT) is able to non-invasively treat and diagnose various cancers and nonmalignant diseases by combining light, oxygen, and photosensitizers (PSs). However, the application of PDT is hindered by poor water solubility and limited light-penetration depth of the currently available photosensitizers (PSs). Water solubility of PSs is crucial for designing pharmaceutical formulation and administration routes. Wavelength of light source at visible range normally has therapeutic depth less than 1 mm. In this review, focus is on the recent research progress of metal-based nanoparticles being applied in PDT. The potential toxicity of these nanoscales and future directions are further discussed.

Preparation of cupric sulfate-based self-emulsifiable nanocomposites and their application to the photothermal therapy of colon adenocarcinoma

Nanocomposites (NCs) of cupric sulfate monohydrate (CuSO₄) were fabricated by hot-melt extrusion (HME) system equipped with twin screws. Micron-sized bulk powder of CuSO₄ was dispersed in the mixture of surfactants (Span 80 and Tween 80) and hydrophilic polymer (polyethylene glycol (PEG) 6000) by HME process. Reduction of surface tension by surfactants and homogeneous dispersion in hydrophilic polymer along with HME technique were introduced to prepare CuSO₄ NCs. Dispersion of CuSO₄ NCs exhibited approximately 204 nm hydrodynamic size, unimodal size distribution, and positive zeta potential values. Encapsulation of CuSO₄ in CuSO₄ NCs and the physicochemical interactions between CuSO₄ and pharmaceutical excipients were investigated by solid-state studies. Of note, CuSO₄ NCs group exhibited higher antiproliferation efficacies, compared with bulk CuSO₄, in Caco-2 (human adenocarcinoma) cells at 75 and 100 μg/mL CuSO₄ concentrations (p < 0.05). Also, near-infrared laser irradiation to CuSO₄ NCs group elevated the antiproliferation efficacies, compared with non-irradiation group, in Caco-2 cells. After intravenous injection in mice, CuSO₄ NCs did not show severe in vivo toxicities. Developed CuSO₄ NCs can be one of promising candidates of photothermal therapeutic agents for colon cancers.

Iron Oxide Nanoparticles in Photothermal Therapy

Photothermal therapy is a kind of therapy based on increasing the temperature of tumoral cells above 42 °C. To this aim, cells must be illuminated with a laser, and the energy of the radiation is transformed in heat. Usually, the employed radiation belongs to the near-infrared radiation range. At this range, the absorption and scattering of the radiation by the body is minimal. Thus, tissues are almost transparent. To improve the efficacy and selectivity of the energy-to-heat transduction, a light-absorbing material, the photothermal agent, must be introduced into the tumor. At present, a vast array of compounds are available as photothermal agents. Among the substances used as photothermal agents, gold-based compounds are one of the most employed. However, the undefined toxicity of this metal hinders their clinical investigations in the long run. Magnetic nanoparticles are a good alternative for use as a photothermal agent in the treatment of tumors. Such nanoparticles, especially those formed by iron oxides, can be used in combination with other substances or used themselves as photothermal agents. The combination of magnetic nanoparticles with other photothermal agents adds more capabilities to the therapeutic system: the nanoparticles can be directed magnetically to the site of interest (the tumor) and their distribution in tumors and other organs can be imaged. When used alone, magnetic nanoparticles present, in theory, an important limitation: their molar absorption coefficient in the near infrared region is low. The controlled clustering of the nanoparticles can solve this drawback. In such conditions, the absorption of the indicated radiation is higher and the conversion of energy in heat is more efficient than in individual nanoparticles. On the other hand, it can be designed as a therapeutic system, in which the heat generated by magnetic nanoparticles after irradiation with infrared light can release a drug attached to the nanoparticles in a controlled manner. This form of targeted drug delivery seems to be a promising tool of chemo-phototherapy. Finally, the heating efficiency of iron oxide nanoparticles can be increased if the infrared radiation is combined with an alternating magnetic field.

Nuclear-Targeted Photothermal Therapy Prevents Cancer Recurrence with Near-Infrared Triggered Copper Sulfide Nanoparticles

Clinical cancer treatments nowadays still face the challenge of recurrence due to the residual cancer cells and minute lesions in surgeries or chemotherapies. To effectively address the problem, we introduce a strategy for constructing cancer cell nuclear-targeted copper sulfide nanoparticles (NPs) with a significant photothermal effect to completely kill residual cancer cells and prevent local cancer recurrence. The NPs could directly target the tumor cells and further enter the nucleus by the surface modification of RGD and TAT peptides. Under the irradiation of 980 nm near-infrared laser, the NPs rapidly increase the temperature of the nucleus, destroy the genetic substances, and ultimately lead to an exhaustive apoptosis of the cancer cells. In vivo experiments show that the designed NPs could effectively treat cancer and prevent the return of cancer with a single laser irradiation for 5 min. The photothermal therapy strategy with nuclear targeting for cancer therapy and anti-recurrence will provide more possibilities to develop efficient platforms for treating cancer.

Erythrocyte-Cancer Hybrid Membrane Camouflaged Hollow Copper Sulfide Nanoparticles for Prolonged Circulation Life and Homotypic-Targeting Photothermal/Chemotherapy of Melanoma

Cellular-membrane-coated nanoparticles have increasingly been pursued to leverage the natural cell functions for enhancing biocompatibility and improved therapeutic efficacy. Taking advantage of specialized cell membranes or combining functions from different membrane types facilitates the strengthening of their functionality. Herein, we fuse membrane materials derived from red blood cells (RBCs) and melanoma cells (B16-F10 cells) to create a hybrid biomimetic coating (RBC-B16), and RBC-B16 hybrid membrane camouflaged doxorubicin (DOX)-loaded hollow copper sulfide nanoparticles (DCuS@[RBC-B16] NPs) are fabricated for combination therapy of melanoma. The DCuS@[RBC-B16] NPs are comprehensively characterized, showing the inherent properties of the both source cells. Compared to the bare CuS NPs, the DCuS@[RBC-B16] NPs exhibit highly specific self-recognition to the source cell line in vitro and achieve markedly prolonged circulation lifetime and enhanced homogeneous targeting abilities in vivo inherited from the source cells. Thus, the DOX-loaded [RBC-B16]-coated CuS NP platform exhibits excellent synergistic photothermal/chemotherapy with about 100% melanoma tumor growth inhibition rate. The reported strategy may contribute to personalized nanomedicine of various tumors by combining the RBCs with a homotypic cancer membrane accordingly on the surface of the nanoparticle.

An easy-to-fabricate clearable CuS-superstructure-based multifunctional theranostic platform for efficient imaging guided chemo-photothermal therapy

Despite drug delivery systems (DDSs) receiving ever-increasing attention, development of a simple, effective, sensitive and clearable drug delivery and multifunctional theranostic nanoplatform for cancer therapy is still highly desirable and remains a challenge. Herein, using a one-step solvothermal method, hollow acanthosphere-like CuS superstructures assembled from ∼10 nm nanoparticles (NPs) were successfully obtained and used as an efficient drug delivery and theranostic platform for photoacoustic (PA) and infrared (IR) thermal imaging-guided cancer combination therapy. The special hollow characteristic of CuS superstructures with mesoporous shells and large cavities grants them high drug loading capacity; they demonstrate near-infrared (NIR)/pH stimuli-sensitive drug release and pronounced synergetic effects of chemo-photothermal therapy both in vitro and in vivo. In particular, our as-fabricated hollow loose CuS superstructures, with easily breakable characteristic, are biodegradable and able to be cleared from the body when their therapy task is completed. This CuS-superstructure-based clearable drug delivery and "all-in-one" cancer theranostic platform might provide possibilities for improving therapeutic efficacy and minimizing adverse effects.

Photothermal-Activatable Fe3O4 Superparticle Nanodrug Carriers with PD-L1 Immune Checkpoint Blockade for Anti-metastatic Cancer Immunotherapy

Checkpoint blockade immunotherapy has shown great potential in clinical cancer therapy, but the body's systemic immune must be fully activated and generates a positive tumor-specific immune cell response. In this work, we demonstrate the design of the immune-adjuvant nanodrug carriers on the basis of poly(ethylene glycol)- block-poly(lactic- co-glycolic acid) copolymer-encapsulated Fe₃O₄ superparticles (SPs), in which imiquimod (R837), a kind of Toll-like receptor 7 agonist, is loaded. The nanodrug carriers are defined as Fe₃O₄-R837 SPs. The multitasking Fe₃O₄-R837 SPs can destroy the 4T1 breast tumor by photothermal therapy (PTT) under near-infrared laser irradiation to generate the tumor-associated antigens because of the high efficiency of tumor magnetic attraction ability and photothermal effect. The PTT also triggers the release of R837 as the adjuvant to trigger a strong antitumor immune response. By further combining with the checkpoint blockade adjusted by programmed death ligand 1 (PD-L1) antibody, the Fe₃O₄-R837 SP-involved PTT cannot only eliminate the primary tumors but also prevent tumor metastasis to lungs/liver. Meanwhile, this synergistic therapy also shows abscopal effects by completely inhibiting the growth of untreated distant tumors through effectively triggering the tumors infiltrated by CD45⁺ leukocytes. Such findings suggest that Fe₃O₄-R837 SP-involved PTT can significantly potentiate the systemic therapeutic efficiency of PD-L1 checkpoint blockade therapy by activating both innate and adaptive immune systems in the body.

Shining Light on Chitosan: A Review on the Usage of Chitosan for Photonics and Nanomaterials Research

Chitosan (CS) is a natural polymer derived from chitin that has found its usage both in research and commercial applications due to its unique solubility and chemical and biological attributes. The biocompatibility and biodegradability of CS have helped researchers identify its utility in the delivery of therapeutic agents, tissue engineering, wound healing, and more. Industrial applications include cosmetic and personal care products, wastewater treatment, and corrosion protection, to name a few. Many researchers have published numerous reviews outlining the physical and chemical properties of CS, as well as its use for many of the above-mentioned applications. Recently, the cationic polyelectrolyte nature of CS was found to be advantageous for stabilizing fascinating photonic materials including plasmonic nanoparticles (e.g., gold and silver), semiconductor nanoparticles (e.g., zinc oxide, cadmium sulfide), fluorescent organic dyes (e.g., fluorescein isothiocyanate (FITC)), luminescent transitional and lanthanide complexes (e.g., Au(I) and Ru(II), and Eu(III)). These photonic systems have been extensively investigated for their usage in antimicrobial, wound healing, diagnostics, sensing, and imaging applications. Highlighted in this review are the different works involving some of the above-mentioned molecular-nano systems that are prepared or stabilized using the CS polymer. The advantages and the role of the CS for synthesizing and stabilizing the above-mentioned optically active materials have been illustrated.