Fluorescence guided photothermal/photodynamic ablation of tumours using pH-responsive chlorin e6-conjugated gold nanorods

Vaporization phosphorization-mediated synthesis of phosphorus-doped TiO2 nanocomposites for combined photodynamic and photothermal therapy of renal cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is a disease with high incidence and poor prognosis. The conventional treatment involves radiotherapy and chemotherapy, but chemotherapeutic agents are often associated with side effects, i.e., cytotoxicity to nontumor cells. Therefore, there is an urgent need for the development of novel therapeutic strategies for ccRCC. We synthesized spherical P/TiO2 nanoparticles (P/TiO2 NPs) by vaporization phosphorization (VP). X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS) analyses confirmed that the anatase TiO2 surface was successfully doped with phosphorus and produced a large number of oxygen vacancies (OV). Serving as a photosensitizer, P/TiO2 NPs not only extended the photoresponse range to the near-infrared II region (NIR II) but also introduced a donor energy level lower than the TiO2 conduction band, narrowing the band gap, which could facilitate the migration of photogenerated charges and trigger the synergistic treatment of photodynamic therapy (PDT) and photothermal therapy (PTT). During NIR irradiation in vitro, the P/TiO2 NPs generated local heat and various oxygen radicals, including 1O2, ˙O2-, H2O2, and ˙OH, which damaged the ccRCC cells. In vivo, administration of the P/TiO2 NPs + NIR reduced the tumor volume by 80%, and had the potential to inhibit tumor metastasis by suppressing intratumor neoangiogenesis. The P/TiO2 NPs showed superior safety and efficacy relative to the conventional chemotherapeutic agent used in ccRCC treatment. This study introduced an innovative paradigm for renal cancer treatment, highlighting the potential of P/TiO2 NPs as safe and effective nanomaterials and presenting a compelling new option for clinical applications in anticancer therapy.

Ce6-modified Fe ions-doped carbon dots as multifunctional nanoplatform for ferroptosis and photodynamic synergistic therapy of melanoma

BACKGROUND

Despite the higher sensitivity of melanoma towards ferroptosis and photodynamic therapy (PDT), the lack of efficient ferroptosis inducers and the poor solubility of photosensitizers restrict their synergistic strategies. With unique advantages, carbon dots (CDs) are expected to serve as innovative building blocks for combination therapy of cancers.

RESULTS

Herein, an ferroptosis/PDT integrated nanoplatform for melanoma therapy is constructed based on chlorin e6-modified Fe ions-doped carbon dots (Fe-CDs@Ce6). As a novel type of iron-carbon hybrid nanoparticles, the as-prepared Fe-CDs can selectively activate ferroptosis, prevent angiogenesis and inhibit the migration of mouse skin melanoma cells (B16), but have no toxicity to normal cells. The nano-conjugated structures facilitate not only the aqueous dispersibility of Ce6, but also the self-accumulation ability of Fe-CDs@Ce6 within melanoma area without requiring extra targets. Moreover, the therapeutic effects of Fe-CDs@Ce6 are synergistically enhanced due to the increased GSH depletion by PDT and the elevated singlet oxygen (1O2) production efficiency by Fe-CDs. When combined with laser irradiation, the tumor growth can be significantly suppressed by Fe-CDs@Ce6 through cyclic administration. The T2-weighted magnetic resonance imaging (MRI) capability of Fe-CDs@Ce6 also reveals their potentials for cancer diagnosis and navigation therapy.

CONCLUSIONS

Our findings indicate the multifunctionality of Fe-CDs@Ce6 in effectively combining ferroptosis/PDT therapy, tumor targeting and MRI imaging, which enables Fe-CDs@Ce6 to become promising biocompatible nanoplatform for the treatment of melanoma.

A novel polymer enabled by polymerized small molecule strategy for tumor photothermal and photodynamic therapy

Photothermal therapy (PTT) and photodynamic therapy (PDT) are effective method for tumor treatment. However, the limited variety and quantity of photothermal agents (PTAs) and photosensitizer (PSs) are still major challenges. Moreover, the cell apoptosis mechanism induced by PDT and PTT is still elusive. A fused-ring small molecule acceptor-donor acceptor' donor-acceptor (A-DA'D-A) type of Y5 (Scheme 1) has a narrow band-gap and strong light absorption. Herein, we used Y5 to polymerize with thiophene unit to obtain polymer PYT based on polymerized small molecule strategy, and PYT nanoparticles (PYT NPs) was prepared via one-step nanoprecipitation strategy with DSPE-PEG2000. PYT NPs had excellent biocompatibility, good photostability, high photothermal conversion efficiency (67%) and reactive oxygen species (ROS) production capacity under 808 nm laser irradiation (PYT NPs + NIR). In vitro and in vivo experiments revealed that PYT NPs + NIR had the ability to completely ablate tumor cells. It was demonstrated that cell apoptosis induced by PYT NPs + NIR was closely related to mitochondrial damage. This study provides valuable guidance for constructing high-performance organic PTAs and PSs for tumor treatment. Scheme 1 PYT enabled by polymerized small molecule strategy for tumor photothermal and photodynamic therapy.

Near infrared II excitation nanoplatform for photothermal/chemodynamic/antibiotic synergistic therapy combating bacterial biofilm infections

Drug-resistant bacterial biofilm infections (BBIs) are refractory to elimination. Near-infrared-II photothermal therapy (NIR-II PTT) and chemodynamic therapy (CDT) are emerging antibiofilm approaches because of the heavy damage they inflict upon bacterial membrane structures and minimal drug-resistance. Hence, synergistic NIR-II PTT and CDT hold great promise for enhancing the therapeutic efficacy of BBIs. Herein, we propose a biofilm microenvironment (BME)-responsive nanoplatform, BTFB@Fe@Van, for use in the synergistic NIR-II PTT/CDT/antibiotic treatment of BBIs. BTFB@Fe@Van was prepared through the self-assembly of phenylboronic acid (PBA)-modified small-molecule BTFB, vancomycin, and the CDT catalyst Fe2+ ions in DSPE-PEG2000. Vancomycin was conjugated with BTFB through a pH-sensitive PBA-diol interaction, while the Fe2+ ions were bonded to the sulfur and nitrogen atoms of BTFB. The PBA-diol bonds decomposed in the acidic BME, simultaneously freeing the vancomycin and Fe2+ irons. Subsequently, the catalytic product hydroxyl radical was generated by the Fe2+ ions in the oxidative BME overexpressed with H2O2. Moreover, under 1064 nm laser, BTFB@Fe@Van exhibited outstanding hyperthermia and accelerated the release rate of vancomycin and the efficacy of CDT. Furthermore, the BTFB@Fe@Van nanoplatform enabled the precise NIR-II imaging of the infected sites. Both in-vitro and in-vivo experiments demonstrated that BTFB@Fe@Van possesses a synergistic NIR-II PTT/CDT/antibiotic mechanism against BBIs.

Recent progress in tannic acid based approaches as a natural polyphenolic biomaterial for cancer therapy: A review

Significant advancements have been noticed in cancer therapy for decades. Despite this, there are still many critical challenges ahead, including multidrug resistance, drug instability, and side effects. To overcome obstacles of these problems, various types of materials in biomedical research have been explored. Chief among them, the applications of natural compounds have grown rapidly due to their superb biological activities. Natural compounds, especially polyphenolic compounds, play a positive and great role in cancer therapy. Tannic acid (TA), one of the most famous polyphenols, has attracted widespread attention in the field of cancer treatment with unique structural, physicochemical, pharmaceutical, anticancer, antiviral, antioxidant and other strong biological features. This review concentrated on the basic structure along with the important role of TA in tuning oncological signal pathways firstly, and then focused on the use of TA in chemotherapy and preparation of delivery systems including nanoparticles and hydrogels for cancer therapy. Besides, the application of TA/Fe3+ complex coating in photothermal therapy, chemodynamic therapy, combined therapy and theranostics is discussed.

Cell-surface photochemistry mediated calcium overload for synergistic tumor therapy

Calcium (Ca2+) is essential for mitochondrial homeostasis and function coordination, particularly in cancer cells that metabolize frequently to sustain their growth. Photochemistry mediated calcium overload has attracted lots of attention as an effective way to achieve tumor suppression. Herein, we developed a photonanomedicine to synergistically induce calcium overload via cell-surface photochemistry and thus tumor suppression. Specifically, the photosensitizer, protoporphyrin IX (PpIX) was loaded onto upconversion nanoparticles (UCNP), which was subsequently modified by a polymer bearing photo-crosslinking cinnamate (CA) groups. The resulting nanoparticle was further functionalized by anti-CD20 aptamers (Apt), to give photonanomedicine. The interaction between CD20 receptors and anti-CD20 aptamers allowed photonanomedicine to accurately attach onto the Raji cell surface after an intravenous injection. Following the local application of a 980 nm NIR laser, the photonanomedicine was able to capture the NIR light and convert it into ultraviolet (UV) light. On one hand, the converted UV light led the crosslinking of cinnamate groups in photonanomedicine, further stimulating the clustering of CD20 receptors and causing Ca2+ influx. On the other hand, the UV light could simultaneously excited PpIX to generate reactive oxygen species (ROS) in situ to break down the integrity of cell membrane and lead to an influx of Ca2+. The synergistic Ca2+ overload mediated by photonanomedicine exhibited an enhanced and superior anti-tumor efficacy. We believe this photonanomedicine expands the toolbox to manipulate intracellular Ca2+ concentration and holds a great potential as an anti-tumor therapy.

Porphin e6 complex loaded with gold nanorod mesoporous silica enhances photodynamic therapy in ovarian cancer cells in vitro

A growing amount of experimental evidence has proven that the application of gold nanorods (AuNRs) in photodynamic therapy (PDT) can significantly enhance its therapeutic efficacy. The aim of this study was to establish a protocol for investigating the effect of gold nanorods loaded with the photosensitizer chlorin e6 (Ce6) on photodynamic therapy in the OVCAR3 human ovarian cancer cell line in vitro and to determine whether the PDT effect was different from that of Ce6 alone. OVCAR3 cells were randomly divided into three groups: the control group, Ce6-PDT group, and AuNRs@SiO₂@Ce6-PDT group. Cell viability was measured by MTT assay. The generation of reactive oxygen species (ROS) was measured by a fluorescence microplate reader. Cell apoptosis was detected by flow cytometry. The expression of apoptotic proteins was detected by immunofluorescence and western blotting. The results showed that compared with that of the Ce6-PDT group, the cell viability of the AuNRs@SiO₂@Ce6-PDT group was significantly decreased (P < 0.05) in a dose-dependent manner, and ROS production increased significantly (P < 0.05). The flow cytometry results showed that the proportion of apoptotic cells in the AuNRs@SiO₂@Ce6-PDT group was significantly higher than that in the Ce6-PDT group (P < 0.05). Immunofluorescence and western blot results showed that the protein expression levels of cleaved caspase-9, cleaved caspase-3, cleaved PARP, and Bax in the AuNRs@SiO₂@Ce6-PDT-treated-OVCAR3 cells were higher than those in the Ce6-PDT-treated cells (P < 0.05), and the protein expression levels of caspase-3, caspase-9, PARP, and Bcl-2 were slightly lower than those in the Ce6-PDT group (P < 0.05). In summary, our results show that AuNRs@SiO₂@Ce6-PDT has a significantly stronger effect on OVCAR3 cells than the effect of Ce6-PDT alone. The mechanism may be related to the expression of Bcl-2 family and caspase family in the mitochondrial pathway.

Papaya latex mediated synthesis of prism shaped proteolytic gold nanozymes

Beyond natural enzymes, the artificially synthesized nanozymes have attracted a significant interest as it can overcome the limitations of the former. Here, we report synthesis of shape controlled nanozymes showing proteolytic activity using Carica papaya L. (papaya) latex. The nanozymes synthesized under optimized reaction conditions exhibited sharp SPR peak around 550 nm with high abundance (45.85%) of prism shaped particles. FTIR analysis and coagulation test indicated the presence of papaya latex enzymes as capping agents over the gold nanoprisms. The milk clot assay and the inhibition test with egg white confirmed the proteolytic activity of the nanozymes and the presence of cysteine protease on it, respectively. The nanozymes were found to be biocompatible and did not elicit any toxic response in both in-vitro and in-vivo study. Based on our findings, we envisage that these biocompatible, shape-specific nanozymes can have potential theragnostic applications.

Chlorin e6: A Promising Photosensitizer in Photo-Based Cancer Nanomedicine

Conventional cancer treatment modalities are often associated with major therapeutic limitations and severe side effects. Photodynamic therapy is a localized noninvasive mode of treatment that has given a different direction to cancer research due to its effectivity against a wide range of cancers and minimal side effects. A photosensitizer is the key component of photodynamic therapy (PDT) that generates cytotoxic reactive oxygen species to eradicate cancer cells. As the therapeutic effectivity of PDT greatly depends upon the photosensitizer, great efforts have been made to search for an ideal photosensitizer. Chlorin e6 is a FDA approved second generation photosensitizer that meets the desired clinical properties for PDT. It is known for its high reactive oxygen species (ROS) generation ability and anticancer potency against many types of cancer. Hydrophobicity is a major drawback of Ce6 that leads to its poor biodistribution and rapid clearance from the circulatory system. To overcome this drawback, researchers have designed and fabricated several types of nanosystems, which can enhance Ce6 solubility and thereby enhance its bioavailability. These nanosystems also improve tumor accumulation of Ce6 by selectively targeting the cancer cells through passive and active targeting. In addition, Ce6 has been employed in many combination therapies like chemo-photodynamic therapy, photoimmunotherapy, and combined photodynamic-photothermal therapy. A combination therapy is more curative than a single therapy due to the synergistic effects of individual therapies. Ce6-based nanosystems for combination therapies have shown excellent results in various studies and provide a promising platform for cancer treatment.

Nitric oxide-mediated regulation of mitochondrial protective autophagy for enhanced chemodynamic therapy based on mesoporous Mo-doped Cu9S5 nanozymes

The depletion of reactive oxygen species (ROS) by glutathione (GSH) and oxidative stress induced protective autophagy severely impaired the therapeutic effect of chemodynamic therapy (CDT). Therefore, how to construct a CDT treatment nanosystem with high yield and full utilization of ROS in tumor site is the main issue of CDT. Herein, a multifunctional cascade bioreactor based on mesoporous Mo-doped Cu₉S₅ (m-MCS) nanozymes loaded with L-Arginine (LA), abbreviated as m-MCS@LA, is constructed for realizing enhanced CDT promoted by ultrasound (US) triggered gas therapy. The m-MCS based on the catalytic performance of multivalent metal ions, which were served as nanozymes, exhibit enhanced Fenton-like and glutathione (GSH) peroxidase-like activities in comparison to Cu₉S₅ nanoparticles without Mo-doping. Once placed in tumor microenvironment (TME), the existence of redox couples (Cu⁺/Cu²⁺ and Mo⁴⁺/Mo⁶⁺) in m-MCS enabled it to react with hydrogen peroxide (H₂O₂) to generate ·OH for achieving CDT effect via Fenton-like reaction. Meanwhile, m-MCS could consume overexpressed GSH in tumor microenvironment (TME) to alleviate antioxidant capability for enhancing CDT effect. Moreover, m-MCS with mesoporous structure could be employed as the carrier to load natural nitric oxide (NO) donor LA. US as the excitation source with high tissue penetration can trigger m-MCS@LA to produce NO. As the gas transmitter with physiological functions, NO could play dual roles to kill cancer cells through gas therapy directly, and enhance CDT effect by inhibiting protective autophagy simultaneously. As a result, this US-triggered and NO-mediated synergetic cancer chemodynamic/gas therapy based on m-MCS@LA NPs can effectively eliminate primary tumor and achieved tumor-specific treatment, which provide a possible strategy for developing more effective CDT in future practical applications. STATEMENT OF SIGNIFICANCE: The depletion of reactive oxygen species (ROS) by glutathione (GSH) and oxidative stress induced protective autophagy severely impaired the therapeutic effect of chemodynamic therapy (CDT). Herein, a multifunctional cascade bioreactor based on mesoporous Mo-doped Cu₉S₅ (m-MCS) nanozymes loaded with L-Arginine (m-MCS@LA) is constructed for realizing enhanced CDT promoted by ultrasound (US) triggered gas therapy. The m-MCS with double redox couples presents the enhanced enzyme-like activities to perform cascade reactions for reducing GSH and generating ROS. LA loaded by m-MCS can produce NO triggered by US to inhibit the mitochondria protective autophagy for reactivating mitochondria involved apoptosis pathway. The US-triggered and NO-mediated CDT based on m-MCS@LA can effectively eliminate primary tumor through the high yield and full utilization of ROS.

Biodegradable Silk Fibroin Nanocarriers to Modulate Hypoxia Tumor Microenvironment Favoring Enhanced Chemotherapy

Biopolymer silk fibroin (SF) is a great candidate for drug carriers characterized by its tunable biodegradability, and excellent biocompatibility properties. Recently, we have constructed SF-based nano-enabled drug delivery carriers, in which doxorubicin (Dox) and atovaquone (Ato) were encapsulated with Arg-Gly-Asp-SF-Polylactic Acid (RSA) to form micellar-like nanoparticles (RSA-Dox-Ato NPs). The RGD peptide was decorated on micellar-like nanoparticles, promoting tumor accumulation of the drug. Meanwhile, Ato, as a mitochondrial complex III inhibitor inhibiting mitochondrial respiration, would reverse the hypoxia microenvironment and enhance chemotherapy in the tumor. In vitro, the biopolymer alone showed extremely low cytotoxicity to 4T1 cell lines, while the RSA-Dox-Ato demonstrated a higher inhibition rate than other groups. Most significantly, the ROS levels in cells were obviously improved after being treated with RSA-Dox-Ato, indicating that the hypoxic microenvironment was alleviated. Eventually, SF-based targeted drug carrier provides biocompatibility to reverse hypoxia microenvironment in vivo for enhancing chemotherapy, strikingly suppressing tumor development, and thereby suggesting a promising candidate for drug delivery system.

Gold Nanorods for Drug and Gene Delivery: An Overview of Recent Advancements

Over the past few decades, gold nanomaterials have shown great promise in the field of nanotechnology, especially in medical and biological applications. They have become the most used nanomaterials in those fields due to their several advantageous. However, rod-shaped gold nanoparticles, or gold nanorods (GNRs), have some more unique physical, optical, and chemical properties, making them proper candidates for biomedical applications including drug/gene delivery, photothermal/photodynamic therapy, and theranostics. Most of their therapeutic applications are based on their ability for tunable heat generation upon exposure to near-infrared (NIR) radiation, which is helpful in both NIR-responsive cargo delivery and photothermal/photodynamic therapies. In this review, a comprehensive insight into the properties, synthesis methods and toxicity of gold nanorods are overviewed first. For the main body of the review, the therapeutic applications of GNRs are provided in four main sections: (i) drug delivery, (ii) gene delivery, (iii) photothermal/photodynamic therapy, and (iv) theranostics applications. Finally, the challenges and future perspectives of their therapeutic application are discussed.

Progress in Nanocarriers Codelivery System to Enhance the Anticancer Effect of Photodynamic Therapy

Photodynamic therapy (PDT) is a promising anticancer noninvasive method and has great potential for clinical applications. Unfortunately, PDT still has many limitations, such as metastatic tumor at unknown sites, inadequate light delivery and a lack of sufficient oxygen. Recent studies have demonstrated that photodynamic therapy in combination with other therapies can enhance anticancer effects. The development of new nanomaterials provides a platform for the codelivery of two or more therapeutic drugs, which is a promising cancer treatment method. The use of multifunctional nanocarriers for the codelivery of two or more drugs can improve physical and chemical properties, increase tumor site aggregation, and enhance the antitumor effect through synergistic actions, which is worthy of further study. This review focuses on the latest research progress on the synergistic enhancement of PDT by simultaneous multidrug administration using codelivery nanocarriers. We introduce the design of codelivery nanocarriers and discuss the mechanism of PDT combined with other antitumor methods. The combination of PDT and chemotherapy, gene therapy, immunotherapy, photothermal therapy, hyperthermia, radiotherapy, sonodynamic therapy and even multidrug therapy are discussed to provide a comprehensive understanding.

Yolk-Shell-Type Gold Nanoaggregates for Chemo- and Photothermal Combination Therapy for Drug-Resistant Cancers

Epithelial ovarian cancer is a gynecological cancer with the highest mortality rate, and it exhibits resistance to conventional drugs. Gold nanospheres have gained increasing attention over the years as photothermal therapeutic nanoparticles, owing to their excellent biocompatibility, chemical stability, and ease of synthesis; however, their practical application has been hampered by their low colloidal stability and photothermal effects. In the present study, we developed a yolk-shell-structured silica nanocapsule encapsulating aggregated gold nanospheres (aAuYSs) and examined the photothermal effects of aAuYSs on cell death in drug-resistant ovarian cancers both in vitro and in vivo. The aAuYSs were synthesized using stepwise silica seed synthesis, surface amino functionalization, gold nanosphere decoration, mesoporous organosilica coating, and selective etching of the silica template. Gold nanospheres were agglomerated in the confined silica interior of aAuYSs, resulting in the red-shifting of absorbance and enhancement of the photothermal effect under 808 nm laser irradiation. The efficiency of photothermal therapy was first evaluated by inducing aAuYS-mediated cell death in A2780 ovarian cancer cells, which were cultured in a two-dimensional culture and a three-dimensional spheroid culture. We observed that photothermal therapy using aAuYSs together with doxorubicin treatment synergistically induced the cell death of doxorubicin-resistant A2780 cancer cells in vitro. Furthermore, this type of combinatorial treatment with photothermal therapy and doxorubicin synergistically inhibited the in vivo tumor growth of doxorubicin-resistant A2780 cancer cells in a xenograft transplantation model. These results suggest that photothermal therapy using aAuYSs is highly effective in the treatment of drug-resistant cancers.

A metformin-based nanoreactor alleviates hypoxia and reduces ATP for cancer synergistic therapy

Severe hypoxia in solid tumors limits the efficacy of oxygen (O₂)-dependent photodynamic therapy (PDT). The overexpressed heat shock proteins (HSPs) in tumor cells hamper the effect of photothermal therapy (PTT). Herein, a tumor oxygenation-enhanced and ATP-reduced gelatin nanoreactor (MCGPD ∼ RGD NPs) for PDT/PTT-augmented combination cancer therapy is reported. In this nanosystem, the Arg-Gly-Asp (RGD) peptides of MCGPD ∼ RGD NPs can ensure accurate recognition and sufficient accumulation in the tumor site. After accumulation, doxorubicin (DOX) can be released from MCGPD ∼ RGD NPs in a mild acidic tumor microenvironment (TME) for highly efficient chemotherapy. Upon 808 nm laser irradiation, the overexpressed matrix metalloproteinase-2 (MMP-2) in the TME and the heat produced from the PDA coating trigger Gel NP degradation to expose chlorin e6 (Ce6) and Met from the cavity of MCGPD ∼ RGD NPs. The exposed Met elevates the O₂ content and reduces ATP production in tumor sites to spur the successful O₂-dependent PDT and HSP-mediated PTT. The heat generated by the PDA coating directly kills the tumor cells to ensure PTT and amplifies the chemotherapeutic effect. In vitro and in vivo assays indicate that MCGPD ∼ RGD NPs have excellent ability to promote cell apoptosis and to inhibit tumor growth. Overall, this smart responsive hydrogel nanosystem with hypoxia-relieving capacity and ATP-decreasing performance provides a promising strategy against cancer.

Tumor microenvironment-responsive nanozymes achieve photothermal-enhanced multiple catalysis against tumor hypoxia

Reactive oxygen species (ROS)-mediated antitumor modalities that induced oxidative damage of cancer cells have recently acquired increasing attention on account of their noninvasiveness, low systemic toxicity, and high specificity. However, their clinical efficacy was often constrained by complex and various tumor microenvironment (TME), especially hypoxia characteristic and antioxidation effect of glutathione (GSH). Herein, we constructed a multinanozyme system based on hyaluronic acid (HA)-stabilized CuMnO_x nanoparticles (CMOH) loaded with indocyanine green (ICG) with high-efficient ROS generation, O₂ self-evolving function, GSH depletion ability and hyperthermia effect for achieving hypoxic tumor therapy. The CMOH nanozymes exhibited peroxidase-like and oxidase-like activities, which could efficiently catalyze H₂O₂ or O₂ to generate hydroxyl radicals (•OH) or superoxide radicals (•O₂^-) in acidic tumor microenvironment (TME), elevating oxidative stress of tumor. Indocyanine green (ICG) was further loaded into HA-CuMnO_x to form HA-CuMnO_x@ICG nanocomposites (CMOI NCs), which can effectively generate singlet oxygen (¹O₂) and local hyperthermia under light irradiation. The hyperthermia generated by CMOI NCs further enhances the catalytic activities of nanozymes for ROS generation. Meanwhile, the CMOI with catalase-like activity could catalyze H₂O₂ into O₂ for relieving tumor hypoxia and elevate O₂-dependent ROS generation. Notably, CMOI can consume endogenous GSH, thereby impairing tumor antioxidant system and enhancing ROS-based therapy efficacy. After modified with HA, CMOI NCs with tumor targeting ability realized synergistic PTT-enhanced tumor oxidation therapy based on their multimodal properties. Thus, this work contributes to design high-performance therapeutic reagent to overcome the limitation of hypoxia and high antioxidant defense of tumor. STATEMENT OF SIGNIFICANCE: Reactive oxygen species (ROS)-mediated antitumor modalities were often constrained by complex and various tumor microenvironment (TME), especially hypoxia characteristic and antioxidation effect of glutathione (GSH). In this work, a multinanozyme system based on hyaluronic acid (HA)-stabilized CuMnO_x nanoparticles (CMOH) loaded with indocyanine green (ICG) was designed to realize PTT-enhanced multiple catalysis tumor therapy. Although antitumor modalities based on multienzyme catalysis have been developed. Here, we highlighted the responsive catalysis of multienzyme system on tumor microenvironment (TME) and the promoting effect of photothermal effect on ROS production. Both in vitro and in vivo manifested that the enhanced anticancer efficacy of CMOI NCs due to their thermally amplified catalytic activity and TME regulation ability.

Upper-Critical-Solution-Temperature Polymer Modified Gold Nanorods for Laser Controlled Drug Release and Enhanced Anti-Tumour Therapy

Photothermal therapy (PTT) has become effective method for the treatment of malignant cancer. The development of PTT system with high anti-tumour effect is still the feasible research direction. Here, a new type of gold nanorods (AuNRs)-doxorubicin (DOX)/mPEG_10K-peptide/P(AAm-co-AN) (APP-DOX) nano drug delivery system was proposed. Among them, AuNRs was used as high-efficiency photothermal agent. APP-DOX had a suitable size and can be targeted to accumulate in tumour tissues through circulation in the body. The abundant matrix metalloproteinase 2 (MMP-2) in the tumour environment intercepted and cut off the short peptide chain structure grafted on APP-DOX. At the same time, the removal of the PEG segment leaded to an increase in the hydrophobic properties of the system. Nanoparticles aggregated into large particles, causing them to stay and aggregate further at the tumour site. When irradiated by 808 nm near-infrared laser, APP-DOX achieved a gradual heating process. High temperature can effectively ablate tumours and enable UCST polymer to achieve phase transition, resulting in more anti-cancer drugs loaded in the polymer layer DOX was released, effectively killing cancer cells. Animal experiments had verified the possibility of the nano drug-carrying system and good tumour treatment effect. What’s more worth mentioning is that compared with free DOX, the nano drug delivery system had lower biological toxicity and not cause obvious harmful effects on normal organs and tissues.

A H2S-Triggered Dual-Modal Second Near-Infrared/Photoacoustic Intelligent Nanoprobe for Highly Specific Imaging of Colorectal Cancer

An endogenous H₂S-triggered intelligent optical nanoprobe combining second near-infrared (NIR-II) fluorescence with photoacoustic (PA) imaging can provide more comprehensive information to further improve the sensitivity and reliability of diagnosis for colorectal tumor, which is rarely explored. Herein, an endogenous H₂S-triggered SiO₂@Ag nanoprobe was designed for in situ dual-modal NIR-II/PA imaging of colorectal cancer. The designed dual-modal nanoprobe can be converted to SiO₂@Ag₂S after in situ biosynthesis via a sulfuration reaction with the over-expressed endogenous H₂S in the colorectal tumor. More importantly, the designed SiO₂@Ag nanoprobe exhibits high sensitivity and specificity for diagnosing colorectal cancer in vivo via dual-modal NIR-II/PA imaging. These results provide a new NIR-II/PA dual-modal imaging strategy for noninvasive intelligent detection of colorectal cancer.

Fluorescence Spectroscopy of Porphyrins and Phthalocyanines: Some Insights into Supramolecular Self-Assembly, Microencapsulation, and Imaging Microscopy

The molecular interactions of anionic tetrasulfonate phenyl porphyrin (TPPS) with poly(amido amine) (PAMAM) dendrimers of generation 2.0 and 4.0 (G2 and G4, respectively) forming H- or J-aggregates, as well as with human and bovine serum albumin proteins (HSA and BSA), were reviewed in the context of self-assembly molecular complementarity. The spectroscopic studies were extended to the association of aluminum phthtalocyanine (AlPCS4) detected with a PAMAM G4 dendrimer with fluorescence studies in both steady state and dynamic state, as well as due to the fluorescence quenching associated to electron-transfer with a distribution of lifetimes. The functionalization of TPPS with peripheral substituents enables the assignment of spontaneous pH-induced aggregates with different and well-defined morphologies. Other work reported in the literature, in particular with soft self-assembly materials, fall in the same area with particular interest for the environment. The microencapsulation of TPPS studies into polyelectrolyte capsules was developed quite recently and aroused much interest, which is well supported and complemented by the extensive data reported on the Imaging Microscopy section of the Luminescence of Porphyrins and Phthalocyanines included in the present review.

γ-Glutamyl transpeptidase-activatable near-infrared nanoassembly for tumor fluorescence imaging-guided photothermal therapy

Rationale: Precise treatment of tumors is attracting increasing attention. Molecular probes simultaneously demonstrating the diagnostic signal and pharmacological effect in response to tumor microenvironment are highly desired. γ-glutamyl transpeptidase (GGT) is a biomarker with significantly up-regulated expression in the tumor area. We developed a GGT responsive near-infrared (NIR) nanoassembly for tumor-specific fluorescence imaging-guided photothermal therapy. Methods: The GGT responsive NIR probe was constructed by conjugating GGT-specific substrate γ-glutamic acid (γ-Glu) with cyanine fluorophore (NRh-NH2) via amide reaction. The resulting NRh-G spontaneously assembled into nanoparticles (NRh-G-NPs) around 50 nm. The NPs were characterized and the properties evaluated in the presence or absence of GGT. Subsequently, we studied fluorescence imaging and photothermal therapy of NRh-G-NPs in vitro and in vivo. Results: NRh-G-NPs, upon specific reaction with GGT, turned into NRh-NH2-NPs, showing a ~180-fold fluorescence enhancement and excellent photothermal effect recovery. NRh-G-NPs could selectively light up U87MG tumor cells while their fluorescence was weak in L02 human normal liver cells. The NPs also showed excellent tumor cell ablation upon laser irradiation. After intravenous injection into tumor-bearing mice, NRh-G-NPs could arrive in the tumor area and specifically light up the tumor. Following laser irradiation, the tumor could be completely erased with no tumor reoccurrence for up to 40 days. Conclusions: NRh-G-NPs were specifically responsive to GGT overexpressed in U87MG tumor cells and selectively lit up the tumor for imaging-guided therapy. Besides, the recovery of photothermal property in the tumor area could improve cancer therapy precision and decreased side effects in normal tissues.

Construction of Smart Nanotheranostic Platform Bi-Ag@PVP: Multimodal CT/PA Imaging-Guided PDT/PTT for Cancer Therapy

High-efficiency nanotheranostic agents with multimodal imaging guidance have attracted considerable interest in the field of cancer therapy. Herein, novel silver-decorated bismuth-based heterostructured polyvinyl pyrrolidone nanoparticles (NPs) with good biocompatibility (Bi-Ag@PVP NPs) were synthesized for accurate theranostic treatment, which can integrate computed tomography (CT)/photoacoustic (PA) imaging and photodynamic therapy/photothermal therapy (PDT/PTT) into one platform. The Bi-Ag@PVP NPs can enhance light absorption and achieve a better photothermal effect than bismuth NPs. Moreover, after irradiation under an 808 nm laser, the Bi-Ag@PVP NPs can efficiently induce the generation of reactive oxygen species (ROS), thereby synergizing PDT/PTT to exert an efficient tumor ablation effect both in vitro and in vivo. Furthermore, Bi-Ag@PVP NPs can also be employed to perform enhanced CT/PA imaging because of their high X-ray absorption attenuation and enhanced photothermal conversion. Thus, they can be utilized as a highly effective CT/PA imaging-guided nanotheranostic agent. In addition, an excellent antibacterial effect was achieved. After irradiation under an 808 nm laser, the Bi-Ag@PVP NPs can destroy the integrity of Escherichia coli, thereby inhibiting E. coli growth, which can minimize the risk of infection during cancer therapy. In conclusion, our study provides a novel nanotheranostic platform that can achieve CT/PA-guided PDT/PTT synergistic therapy and have potential antibacterial properties. Thus, this work provides an effective strategy for further broad clinical application prospects.

Improvement of Gold Nanorods in Photothermal Therapy: Recent Progress and Perspective

Cancer is a life-threatening disease, and there is a significant need for novel technologies to treat cancer with an effective outcome and low toxicity. Photothermal therapy (PTT) is a noninvasive therapeutic tool that transports nanomaterials into tumors, absorbing light energy and converting it into heat, thus killing tumor cells. Gold nanorods (GNRs) have attracted widespread attention in recent years due to their unique optical and electronic properties and potential applications in biological imaging, molecular detection, and drug delivery, especially in the PTT of cancer and other diseases. This review summarizes the recent progress in the synthesis methods and surface functionalization of GNRs for PTT. The current major synthetic methods of GNRs and recently improved measures to reduce toxicity, increase yield, and control particle size and shape are first introduced, followed by various surface functionalization approaches to construct a controlled drug release system, increase cell uptake, and improve pharmacokinetics and tumor-targeting effect, thus enhancing the photothermal effect of killing the tumor. Finally, a brief outlook for the future development of GNRs modification and functionalization in PTT is proposed.

Chlorin e6 and polydopamine modified gold nanoflowers for combined photothermal and photodynamic therapy

Combinational photo-based approaches with enhanced efficacy for cancer therapy have garnered increasing attention in recent years. In this work, a multifunctional system for synergistic photothermal and photodynamic cancer therapy was successfully prepared. The system consists of gold nanoflowers (AuNFs) conjugated with Chlorin e6 (Ce6), and then coated with a polydopamine (PDA) layer. AuNFs with diameters around 80 nm and a broad absorbance in the visible-near infrared (Vis-NIR) range of 500 to 800 nm, were successfully synthesized by a two-step process at 0 °C, using HAuCl4, ascorbic acid (AA), and hydroxylamine hydrochloride (NH2OH·HCl) as the reactants. Glutathione (GSH) molecules chemically anchored to the gold surfaces were used to provide addressable sites for Ce6 conjugated to GSH-AuNFs through an amidation reaction. A PDA layer was then wrapped outside the Ce6-GSH-AuNFs via self-polymerization of dopamine, which provided additional chemical modification and functionalization. Finally, the multifunctional PDA-Ce6-GSH-AuNFs were obtained. The content of Ce6 incorporated into the AuNFs was 14.0 wt%, and the singlet oxygen yield of PDA-Ce6-GSH-AuNFs was approximately 91.0% of that of free Ce6. PDA-Ce6-GSH-AuNFs showed better photothermal conversion efficiency (η = 23.6%), lower cytotoxicity, and faster cell internalization. Both in vitro and in vivo investigation of the combined treatment with a near-infrared (NIR) laser (660 nm for photodynamic therapy, and 808 nm for photothermal therapy) demonstrated that PDA-Ce6-GSH-AuNFs had excellent phototoxicity and synergistic effects of killing cancer cells. Hence, PDA-Ce6-GSH-AuNFs are a dual phototherapeutic agent that exhibits photodynamic and photothermal therapeutic effects and has potential application in enhanced cancer therapy.

Engineering of a dual-modal phototherapeutic nanoplatform for single NIR laser-triggered tumor therapy

Theranostic nanoplatforms integrating simultaneously photodynamic therapy (PDT) and photothermal therapy (PTT) exhibit intrinsic advantages in tumor therapy due to distinct mechanisms of action. However, it is challenging to achieve PDT and PTT under single near-infrared (NIR) laser irradiation with a nanoplatform utilizing conventional organic photodynamic agent and inorganic photothermal agent owing to the difference in inherent excitation wavelengths. Particularly, the single NIR light (660 nm)-triggered PTT and PDT nanoplatform, constructed from chlorin e6 (Ce6) and copper sulfide (CuS) nanoparticles (NPs), has never been reported. Herein, we, for the first time, designed and established a dual-modal phototherapeutic nanoplatform that achieved both PTT and PDT under single NIR laser (660 nm) irradiation for Ce6 and CuS NPs with the strategy of core-shell structured CuS@Carbon integrated with Ce6. Introducing of carbon shell not only endows small CuS NPs with excellent tumor accumulation, but also significantly strengthens the photothermal performance of CuS NPs, realizing efficient photothermal performance under 660 nm laser irradiation. Moreover, Ce6 in carbon shell endowed the nanoplatform with photodynamic effect under 660 nm laser irradiation. The as-prepared Ce6/CuS@Carbon nanoplatform thus achieved dual-modal phototherapy under single NIR laser irradiation, significantly inhibiting tumor growth with minimal adverse effects and superior biosafety.

Targeted theranostics of lung cancer: PD-L1-guided delivery of gold nanoprisms with chlorin e6 for enhanced imaging and photothermal/photodynamic therapy

Peptide modified nanoparticles have emerged as powerful tools for enhanced cancer diagnosis and novel treatment strategies. Here, human programmed death-ligand 1 (PD-L1) peptides were used for the first time for the modification of gold nanoprisms (GNPs) to enhance targeting efficiency. A multifunctional nanoprobe was developed that the GNPs@PEG/Ce6-PD-L1 peptide (GNPs@PEG/Ce6-P) was used for imaging-guided photothermal/photodynamic therapy by using the targeting effect of PD-L1. Both confocal imaging and flow cytometry experiments demonstrated a remarkable affinity of the as-prepared nanoprobes GNPs@PEG/Ce6-P to lung cancer cells (HCC827), which have a high PD-L1 expression. Subsequent in vitro and in vivo experiments further demonstrated that the nanoprobes GNPs@PEG/Ce6-P not only allowed for real-time visualization via fluorescence (FL) imaging and photoacoustic (PA) imaging, but also served as phototherapy agents for synergistic photothermal therapy (PTT) and photodynamic therapy (PDT). Furthermore, treatments on human lung cancer cells-derived tumors demonstrated that the nanoprobes GNPs@PEG/Ce6-P could significantly suppress tumor growth through PTT and PDT from GNPs and Ce6, respectively. In conclusion, the as-prepared new nanoprobes show promising potential for nanomedicine with remarkable targeting ability for dual-mode imaging and enhanced PDT and PTT effects on lung cancer.

Construction of thiol-capped ultrasmall Au-Bi bimetallic nanoparticles for X-ray CT imaging and enhanced antitumor therapy efficiency

Thiol capped gold nanoparticles with small size, high dispersity, and broad light absorption covering ultraviolet (UV) to near infrared (NIR) region have been developed for catalysis, fluorescence imaging and photodynamic therapy (PDT). The constitution of the metal core in such nanoparticles can strongly influence the luminescence, catalysis, and stability properties. However, to date, a corresponding investigation of the influence of the metallic core on the generation of reaction oxygen species (ROS) and its therapeutic efficiency towards tumor cells remains to be lacking. Herein, we fabricated bimetallic nanoparticles by introducing bismuth into captopril capped gold nanoparticles. Surprisingly, the introduction of the Bi was found enhance the photothermal effect of the nanoparticles to a great extent, and the variation trends for the thermal effect, ROS generation rate, and tumor cell inhibition effect were found to disparate with the changes in the Au and Bi composition. The origin of the photothermal effect was deduced through density functional theory calculations based on microscopic construction. Combined with the intrinsic photodynamic effect, the bimetallic nanoparticles showed an outstanding tumor cell inhibition effect. Furthermore, due to the excellent CT imaging property, our designed nanoparticles provide the exciting possibility to realize CT imaging guided and light-mediated tumor therapy.

Targeted Gene Silencing BRAF Synergized Photothermal Effect Inhibits Hepatoma Cell Growth Using New GAL-GNR-siBRAF Nanosystem

Liver cancer is one of the most common malignancies worldwide. The RAF kinase inhibitors are effective in the treatment of hepatocellular carcinoma (HCC); therefore, inhibition of the BRAF/MEK/ERK pathway has become a new therapeutic strategy for novel HCC therapy. However, targeted specific delivery systems for tumors are still significant obstacle to clinical applications. Galactose (GAL) can target the asialoglycoprotein receptor (ASGPR) that is highly expressed on liver cancer cells. In this study, we designed a novel multifunctional nanomaterial GAL-GNR-siBRAF which consists of three parts, GAL as the liver cancer-targeting moiety, golden nanorods (GNR) offering photothermal capability under near infrared light, and siRNA specifically silencing BRAF (siBRAF). The nanocarrier GAL-GNR-siBRAF showed high siRNA loading capacity and inhibited the degradation of siRNA in serum. Compared with naked gold nanorods, GAL-GNR-siBRAF possessed lower biotoxicity and higher efficacy of gene silencing. Treatment with GAL-GNR-siBRAF significantly downregulated the expression of BRAF and impaired proliferation, migration, and invasion of liver cancer cells. Moreover, combinatorial photothermal effects and BRAF knockdown by GAL-GNR-siBRAF effectively given rise to tumor cell death. Therefore, our study developed a new type of targeted multi-functional nanomaterial GAL-GNR-siBRAF for the treatment of liver cancer, which provides ideas for the development of new clinical treatment methods.

Biogenic nanobubbles for effective oxygen delivery and enhanced photodynamic therapy of cancer

Tumor hypoxia is believed to be a factor limiting successful outcomes of oxygen-consuming cancer therapy, thereby reducing patient survival. A key strategy to overcome tumor hypoxia is to increase the prevalence of oxygen at the tumor site. Oxygen-containing microbubbles/nanobubbles have been developed to supply oxygen and enhance the effects of therapies such as radiotherapy and photodynamic therapy. However, the application of these bubbles is constrained by their poor stability, requiring major workarounds to increase their half-lives. In this study, we explore the potential of biogenic gas vesicles (GVs) as a new kind of oxygen carrier to alleviate tumor hypoxia. GVs, which are naturally formed, gas-filled, protein-shelled compartments, were modified on the surface of their protein shells by a layer of liposome. A substantial improvement of oxygen concentration was observed in hypoxic solution, in hypoxic cells, as well as in subcutaneous tumors when lipid-GVs(O₂) were added/tail-injected. Significant enhancement of tumor cell apoptosis and necrosis was also observed during photodynamic therapy (PDT) in the presence of lipid-GVs(O₂) both in vitro and in vivo. Lipid-GVs(O₂) alone induced no obvious change in cell viability in vitro or any apparent pathological abnormalities after mice were tail-injected with them. In all, lipid-GVs exhibited promising performance for intravenous gas delivery, enhanced PDT efficacy and low toxicity, a quality that may be applied to alleviate hypoxia in cancers, as well as hypoxia-related clinical treatments. STATEMENT OF SIGNIFICANCE: The development of stable oxygen-filled micro/nanobubbles capable of delivering oxygen to tumor sites is a major hurdle to enhancing the efficacy of cancer therapy. Currently, micro/nanobubbles are limited by their instability when oxygen is encapsulated, creating a large pressure gradient and surface tension. To improve stability, we modified the surfaces of GVs, a biogenic stable nanoscale hollow structure, as a new class of oxygen carriers. Lipid-coated GVs were found to be stable in solution and effective O₂ carriers. This will overcome the limitations of coalescence, short circulation time of synthetic bubbles during application. Our surface-modified GVs demonstrated low toxicity in vitro cell in vivo, while also being able to overcome hypoxia-associated therapy resistance when combined with photodynamic therapy.

Gold nanobipyramid-loaded black phosphorus nanosheets for plasmon-enhanced photodynamic and photothermal therapy of deep-seated orthotopic lung tumors

Various types of photodynamic agents have been explored for photodynamic therapy (PDT) to destroy cancers located in deep tissues. However, these agents are generally limited by low singlet oxygen (¹O₂) yields owing to weak absorption in the optical transparent window of biological tissues. Accordingly, in this work, we developed a nanocomposite through the assembly of gold nanobipyramids (GNBPs) on black phosphorus nanosheets (BPNSs). This nanocomposite could simultaneously enhance ¹O₂ generation and hyperthermia by localized surface plasmon resonance in cancer therapy. As two-dimensional inorganic photosensitizers, BPNSs were hybridized with GNBPs to form BPNS-GNBP hybrid nanosheets. The hybridization markedly increased ¹O₂ production by the BPNSs through plasmon-enhanced light absorption. The nanocomposite exhibited a higher photothermal conversion efficiency than the BPNSs alone. In vitro and in vivo assays indicated that the BPNS-GNBP hybrid nanocomposite exhibited good tumor inhibition efficacy owing to simultaneous dual-modality phototherapy. In vivo, the nanocomposite suppressed deep-seated tumor growth with minimal adverse effects in mice bearing orthotopic A549 human lung tumors. Taken together, these results demonstrated that our BPNS-GNBP nanocomposite could function as a promising dual-modality phototherapeutic agent for enhanced cancer therapy in future cancer treatments. STATEMENT OF SIGNIFICANCE: In this study, we established a new nanocomposite by assembly of gold nanobipyramids (GNBPs) on black phosphorus nanosheets (BPNSs). Characterization of this nanocomposite showed that BPNS-GNBP enhanced ¹O₂ generation and hyperthermia. BPNS-GNBP exhibited good tumor inhibition efficacy in vivo and in vitro owing to simultaneous dual-modal phototherapy functions. Moreover, BPNS-GNBP suppressed deep-seated tumor growth in vivo and did not show adverse effects in mice bearing orthotopic A549 human lung tumors. Overall, these results showed that BPNS-GNBP may be used as a promising dual-modal phototherapeutic agent for enhanced cancer therapy in future clinical applications.

Fluorescent dye nano-assemblies by thiol attachment directed to the tips of gold nanorods for effective emission enhancement

The conjugation of dye-labelled DNA oligonucleotides with gold nanorods has been widely explored for the development of multifunctional fluorescent nanoprobes. Here, we show that the functionalization route is crucial to achieve enhanced emission in dye nano-assemblies based on gold nanorods. By using a tip-selective approach for thiol attachment of dye molecules onto gold nanorods, it was possible to effectively increase the emission by more than 10-fold relatively to that of a free dye. On the other hand, a non-selective approach revealed that indiscriminate surface functionalization has a detrimental effect on the enhancement. Simulations of discrete dipole approximation gave further insight into the surface distribution of plasmon-enhanced emission by confirming that tip regions afford an effective enhancement, while side regions exhibit a negligible effect or even emission quenching. The contrast between dye nano-assemblies obtained from tip- and non-selective functionalization was further characterized by single-particle fluorescence emission. These studies showed that tip-functionalized gold nanorods with an average of only 30 dye molecules have a comparable to or even stronger emission than non-selectively functionalized particles with approximately 10 times more dye molecules. The results herein reported could significantly improve the performance of dye nano-assemblies for imaging or sensing applications.

Rational design of oxygen deficient TiO2-x nanoparticles conjugated with chlorin e6 (Ce6) for photoacoustic imaging-guided photothermal/photodynamic dual therapy of cancer

Oxygen deficient TiO2-x nanoparticles (NPs) have been recognized as a category of new-fashioned photothermal agents to offer safer PTT. However, the surface of TiO2-x NPs is deficient in free active groups or radicals to conjugate functional therapeutic molecules, which seriously impedes their in-depth development for versatile medical applications. In this study, surface activation of TiO2-x NPs was realized by the facile conjugation of (3-aminopropyl)triethoxysilane (APTES) through the formation of a stable Si-O-Ti bond, and photosensitizer chlorin e6 (Ce6) was successfully modified onto the TiO2-x NP surface and with a considerably high loading content. The resultant TiO2-x@APTES/Ce6 (TAC) NPs displayed decent biosafety, rapid tumor enrichment and outstanding performance in photoacoustic (PA) imaging. Taking advantage of the intense photo-absorption in the near-infrared (NIR) region and high dose of conjugated Ce6, a powerful antitumor effect was realized based on the combination of hyperthermia-induced cell ablation and cytotoxic reactive oxygen species (ROS)-triggered apoptosis both in vitro and in vivo. Moreover, PA imaging guidance was exceptionally useful for locating the tumor position and optimizing the treatment regimens. Apart from Ce6, this elaborate modification strategy for TiO2-x is believed to be universal for steadily binding more versatile therapeutic agents, which would definitely favor the development of multifunctional TiO2-x-based nanocomplexes for enhanced tumor treatment.

Nanoassembly and Multiscale Computation of Multifunctional Optical-Magnetic Nanoprobes for Tumor-Targeted Theranostics

Gold nanorods, mesoporous silica, gadolinia, folic acid, and polyethylene glycol (PEG) derivatives have been investigated due to their own advantages in cancer theranostics. However, it remains a great challenge to assemble these components into a stable unity with the diverse and enhanced functionality for more potential applications. Herein, as inspired by the first-principles calculation, a highly stable and safe all-in-one nanoprobe is fabricated via a novel nanoassembly strategy. Multiscale calculations were performed to address the atomistic bonding of a nanoprobe, heat necrosis of a tumor adjacent to the vasculature, and thermal diffusion in a photothermal circumstance, respectively. The nanoprobe gains an 8-fold increase in magnetic resonance imaging (MRI) relaxivity compared to the clinical gadolinium diethylenetriaminepentaacetate, achieving a significant MRI signal in vivo. Conjugated with folate-PEG, the nanoprobe can be effectively absorbed by tumoral cells, obtaining a vivid two-photon cell imaging. A specific multisite scheme for photothermal therapy of a solid tumor is proposed to improve low photothermal efficacy caused by thermal diffusion in a large tumor, leading to the successful cure of the mice with xenograft tumor sized 10-12 mm. In vitro and in vivo toxicity, long-term excretion data, and the recovery of the treated mice demonstrate that the theranostic nanoprobe possesses good biocompatibility and metabolism efficacy.

Hyaluronic Acid-Modified Porous Carbon-Coated Fe3O4 Nanoparticles for Magnetic Resonance Imaging-Guided Photothermal/Chemotherapy of Tumors

Chemotherapy is an effective method for treating cancer, clinically. However, side effects of drug and multidrug resistance restrict its application. In recent years, the combined treatment of chemotherapy and photothermal therapy (PTT) is becoming a promising method for treating cancer. PTT utilizes nanomaterials absorbing near-infrared light and producing heat to acquire advanced hyperthermia strategy for cancer treatment. Carbon nanomaterials with good biocompatibility, high surface area, and excellent photothermal properties are an excellent nanoplatform for drug delivery and PTT. Herein, porous carbon-coated magnetite nanoparticles (PCCMNs) were successfully synthesized by a one-pot solvothermal method. Magnetite, a contrast agent, can be used for magnetic resonance imaging. Hyaluronic acid was used to modify the PCCMNs to achieve targeted therapy. The obtained nanohybrid with a good photothermal effect can realize combined PTT/chemotherapy and will be a promising nanoplatform for high efficacy theranostics.

TMTP1-modified Indocyanine Green-loaded Polymeric Micelles for Targeted Imaging of Cervical Cancer and Metastasis Sentinel Lymph Node in vivo

Metastasis is one of the most threatening aspects of cervical cancer. We developed a method to intraoperatively map the primary tumor, metastasis and metastatic sentinel lymph nodes (SLNs), providing real-time intraoperative guidance in cervical cancer.

Methods: TMTP1, a tumor metastasis targeting peptide, was employed to modify the indocyanine green (ICG)-loaded poly (ethylene glycol)- poly (lactic-co-glycolic acid) (PEG-PLGA) micelles. The cervical cancer subcutaneous tumor model and lung metastasis model were established to determine the active targeting of ICG-loaded TMTP1-PEG-PLGA micelles (ITM) for the primary tumor and occult metastasis of cervical cancer. Human cervical cancer HeLa cells engineered by firefly luciferase were injected into the right hocks of BALB/c nude mice to develop the SLN metastasis model. The ITM and control ICG-loaded PEG-PLGA micelles (IM) were injected into the right hind footpads in the SLN metastasis model, and the migration and retention of micelles were recorded under near-infrared fluorescence. K14-HPV16 transgenic mice were also used to detect the image capability of ITM to target cancerous lesions.

Results: ITM could actively target imaging of the primary tumor and cervical cancer metastasis. ITM quickly diffused from the injection site to SLNs along lymphatic capillaries and remained in the SLNs for 12 h. Moreover, ITM specifically accumulated in the tumor metastatic SLNs (T-SLNs), which could be successfully distinguished from normal SLNs (N-SLNs).

Conclusion: ITM could achieve active targeting of the primary tumor, metastasis and T-SLNs, providing precise and real-time intraoperative guidance for cervical cancer.

Co-delivery of chlorin e6 and doxorubicin using PEGylated hollow nanocapsules for ‘all-in-one’ tumor theranostics

Aim: Hollow mesoporous copper sulfide nanocapsules conjugated with poly(ethylene glycol) (PEG), doxorubicin and chlorin e6 (HPDC) were synthesized for fluorescence imaging and multimodal tumor therapy. Materials & methods: HPDC were synthesized by encapsulating chlorin e6 and doxorubicin into PEGylated nanocapsules via a simple precipitation method. The photothermal/photodynamic effects, drug release, cellular uptake, imaging capacities and antitumor effects of the HPDCs were evaluated. Results: This smart nanoplatform is stimulus-responsive toward an acidic microenvironment and near infrared laser irradiation. Moreover, fluorescence imaging-guided and combined photothermal/photodynamic/chemotherapies of tumors were promoted under laser activation and led to efficient tumor ablation, as evidenced by exploring animal models in vivo. Conclusion: HPDCs are expected to serve as potent and reliable nanoagents for achieving superior therapeutic outcomes in cancer management.

Nanobiomaterials: from 0D to 3D for tumor therapy and tissue regeneration

Nanobiomaterials have attracted tremendous attention in the biomedical field. Especially in the past few years, a large number of low dimensional nanobiomaterials, including 0D nanostructures, 1D nanotubes and 2D nanosheets, were employed for tumor therapy due to their optically triggered tumor therapy effects and drug loading capacities. However, these low dimensional nanobiomaterials cannot support cell adhesion and possess poor tissue regeneration ability, thus they are not suitable for application in regenerative medicine. Three dimensional (3D) nanofiber scaffolds have attracted extensive attention in tissue regeneration, including bone, skin, nerve and cardiac tissues, due to their similar extracellular matrix structures. Additionally, many 3D scaffolds displayed bone and cartilage regeneration abilities. Therefore, to obtain materials with both tumor therapy and tissue regeneration abilities, it is meaningful and necessary to develop 3D nanobiomaterials with multifunctions. In this review, we systematically review the research progress of nanobiomaterials with varied dimensional structures including 0D, 1D, 2D and 3D, as well as evolutional functions from single tumor therapy to simultaneous tumor therapy and tissue regeneration. This review may pave the way for developing an interdisciplinary research of nanobiomaterials in combination of tumor therapy and regenerative medicine.

Hydroxyl-PEG-Phosphonic Acid-Stabilized Superparamagnetic Manganese Oxide-Doped Iron Oxide Nanoparticles with Synergistic Effects for Dual-Mode MR Imaging

The T₁-T₂ dual-mode contrast agents for magnetic resonance imaging (MRI) can generate self-complementary confirmed T₂ and T₁ images, hence greatly improving the reliability. Facilely synthesizing nanoparticles with the ultrasensitive contrast property remains extremely challenging in nanoscience. Moreover, uncovering the mechanism correlating the signal enhancements and chemical constituents is vital for designing novel efficient synergistically enhanced T₁-T₂ dual-mode MRI nanoprobes. Herein, we report a one-pot facile method to synthesize the superparamagnetic manganese oxide-doped iron oxide (Fe₃O₄/MnO) nanoparticles for T₁-T₂ dual-mode MR imaging. Under external magnetic field, the local magnetic field intensities of MnO and Fe₃O₄ could be simultaneously enhanced through embedding MnO into Fe₃O₄ nanoparticles and hence can cause synergistic T₁ and T₂ contrast enhancements. Moreover, a novel and facile cost-effective method for large-scale synthesis of hydroxyl-polyethylene glycol-phosphonic acid-stabilizing ligands is designed. The facile synthetic method and surface coating strategy of superparamagnetic Fe₃O₄/MnO nanoparticles offer an idea for the chemical design and preparation of superparamagnetic nanoparticles with ultrasensitive MRI contrast abilities for disease evaluation and treatment.

Chlorins e6 loaded silica nanoparticles coated with gastric cancer cell membrane for tumor specific photodynamic therapy of gastric cancer

Background: Photodynamic therapy (PDT) is widely recognized as a promising way to cure cancer. However, the limited tumor homing property of currently available drug delivery systems (DDSs) is the bottleneck for the delivery of photodynamic agents. Purpose: In our study, we decorated silica nanoparticles (SLN) with cell membrane (CM) derived from SGC7901 cells to construct carrier (CM/SLN) which was able to to specifically target the homogenous SGC7901 cells. Materials and methods: Furthermore, the decent drug loading capability of CM/SLN was adopted to load photodynamic agent chlorins e6 (Ce6) to finally construct aDDS suitable for tumor-targeted PDT of gastric cancer. Results: The experimental results suggested that CM/SLN/Ce6 was nano-sized particles with good dispersion and stability in physiological conditions. Moreover, due to the modification of CM,CM/SLN/Ce6 could specifically target the homogenous SGC7901 cells both in vitro and in vivo. Most importantly, further in vivo results demonstrated that the CM/SLN/Ce6 showed a better anticancer outcome compared to SLN/Ce6. Conclusion: CM/SLN/Ce6 might be a promising platform for effective tumor targeted PDT of gastric cancer.

Synthesis of porphyrin-conjugated silica-coated Au nanorods for synergistic photothermal therapy and photodynamic therapy of tumor

Synergistic therapy of tumor has attracted the attention of an increasing number of researchers because of its higher efficiency compared to single therapy. Herein, 4-carboxyphenyl porphyrin-conjugated silica-coated gold nanorods (AuNR@SiO₂-TCPP) were synthesized. The synergistic treatment of photothermal therapy and photodynamic therapy on A549 cancer was researched in vivo and in vitro. In the AuNR@SiO₂-TCPP, Au NRs and TCPP act as photothermal agent and photosensitizer, respectively. The temperature of the AuNR@SiO₂-TCPP (0.11 nmol L^-1) rises to 56.8 °C for 10 min under the illumination of 808 nm laser (2 Wcm^-2). In MTT assays, the viability of A549 cancer cell treated with AuNR@SiO₂-TCPP (100 μg ml^-1) is only 21%. In animal experiments, the relative tumor volumes in mice receiving AuNR@SiO₂-TCPP (5 mg kg^-1) with 660 and 808 nm irradiations were significantly inhibited and the average value is decreased to 0.78 while the average value of the control group is increased to 7.2. These results demonstrate that the AuNR@SiO₂-TCPP is a potential nanomedicine against tumor for clinical application in the near future.

Engineered Cell-Assisted Photoactive Nanoparticle Delivery for Image-Guided Synergistic Photodynamic/Photothermal Therapy of Cancer

Photoactivated therapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), is a spatiotemporally precise, controllable, and noninvasive method for tumor therapy and has therefore attracted increasing attention in recent years. However, it is still a challenge to obtain highly efficient therapeutic photoactive agents (PAAs) and deliver them into tumor, especially the core of solid tumors. Here, we have developed a newly engineered monocyte (MNC)-based PAA system that realizes precise and highly efficient tumor diagnosis and therapy. First, a near-infrared emissive PAA molecule with both strong singlet oxygen (¹O₂) production and high photothermal conversion efficiency was precisely designed for realizing simultaneous PDT and PTT of tumor and was further fabricated to form PAA nanoparticles (NPs). After loading the PAA NPs into MNCs, the MNCs were then decorated with cyclic Arg-Gly-Asp (cRGD) groups through a metabolic labeling method to further improve their ability of targeting and homing into the deep regions of tumors. Using this strategy, we have achieved highly efficient solid tumor ablation results both in vitro and in vivo, indicating that our strategy has a promising prospect for solid tumor therapy.

Plasmonic ELISA for Sensitive Detection of Disease Biomarkers with a Smart Phone-Based Reader

Serum myoglobin is one of the earliest markers for the diagnosis of acute myocardial infarction. It is, therefore, critical to develop a point-of-care testing technology for myoglobin detection. In this work, we reported a sensitive plasmonic immunoassay-based on enzyme-mediated localized surface plasmon resonance change of gold nanorods for the point-of-care testing detection of myoglobin. In addition, we developed a novel plasmonic immunoassay reader using the ambient light sensor of smart phone to increase the accessibility and utility of the plasmonic immunoassay. The linear detection range of gold nanorods-based plasmonic immunoassay for myoglobin detection was 0.1-1000 ng mL-1 and the limit of detection was 0.057 ng mL-1. Myoglobin in serum samples was also analyzed by the plasmonic immunoassay. The results were significantly correlated with those of conventional enzyme-linked immunosorbent assay. The plasmonic immunoassay, coupled with smart phone-based reader, could be widely used for point-of-care testing application of acute myocardial infarction, especially in the regions with limited technological resources.

Rational Design of IR820- and Ce6-Based Versatile Micelle for Single NIR Laser-Induced Imaging and Dual-Modal Phototherapy

Phototherapy as a promising cancer diagnostic and therapeutic strategy has aroused extensive attention. However, single-wavelength near-infrared (NIR) light-triggered combinational treatment of photothermal therapy (PTT) and photodynamic therapy (PDT) is still a great challenge. Herein, a multifunctional micelle activated by a single-wavelength laser for simultaneous PTT and PDT as well as fluorescence imaging is developed. Briefly, new indocyanine green (IR820) is conjugated to d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) via the linker 6-aminocaproic acid, and then, chlorin e6 (Ce6) is encapsulated into the micelles formed by TPGS-IR820 conjugates to fabricate TPGS-IR820/Ce6 micelles. As the well-designed TPGS-IR820 conjugate shares a similar peak absorption wavelength with Ce6, this micelle can be applied with a single NIR laser (660 nm). The stable micelles exhibit excellent photothermal conversion efficiency in vitro and in vivo as well as high singlet oxygen generation capacity in tumor cells. After efficient cellular internalization, the as-prepared micelles display outstanding anticancer activity upon single NIR laser irradiation in vitro and in vivo. Furthermore, TPGS-IR820/Ce6 micelles show negligible systemic toxicity. The highly safe and effective TPGS-IR820/Ce6 micelles can offer an innovative strategy to construct single NIR light-induced PTT and PDT combined phototherapy nanoplatforms via suitable modification of organic phototherapeutic agents.

Functional Polymer Nanocarriers for Photodynamic Therapy

Photodynamic therapy (PDT) is an appealing therapeutic modality in management of some solid tumors and other diseases for its minimal invasion and non-systemic toxicity. However, the hydrophobicity and non-selectivity of the photosensitizers, inherent serious hypoxia of tumor tissues and limited penetration depth of light restrict PDT further applications in clinic. Functional polymer nanoparticles can be used as a nanocarrier for accurate PDT. Here, we elucidate the mechanism and application of PDT in cancer treatments, and then review some strategies to administer the biodistribution and activation of photosensitizers (PSs) to ameliorate or utilize the tumor hypoxic microenvironment to enhance the photodynamic therapy effect.

Tailor-made PL-UC-C3 nanoparticles for fluorescence/computed tomography imaging-guided cascade amplified photothermal therapy

BACKGROUND

Development of the burgeoning number of photothermal therapy (PTT) agents has drawn a huge amount of interest, since PTT treatment is a powerful and effective alternative to traditional treatments. Optimal PTT agents should integrate some essential preconditions including negligible systemic toxicity, deep penetration into tumor tissues, and maximum laser energy absorbance. Unfortunately, only few of the PTT agents reported could meet all of the above mentioned conditions.

METHODS

Here, we report a brand new PTT agent through the encapsulation of NaGdF4:Yb,Tm@ NaGdF4:Yb (UCNPs) and an organic compound (C3) into poly-e-caprolactone-polyethylene-polyglycol (PCL-PEG) (PL-UC-C3 NPs).

RESULTS

UCNPs as an up-conversion material and C3 as a PTT agent both feature low cytotoxicity, and most importantly, UCNPs with superior conversion efficiency could efficiently absorb the energy of a 980 nm laser, transform the near-infrared laser light into visible light, and translate the palingenetic visible light to C3. The usage of a 980 nm laser ensures a deeper penetration and lower energy, while the highly efficient absorption and transformation process confers a cascade amplified hyperthermia for tumor treatment.

CONCLUSION

In this regard, our research provides a powerful and robust breakthrough for florescence/computed tomography imaging-guided PTT treatment, lighting up the clinical application in cancer treatment.

Magnetically targeted photothemal cancer therapy in vivo with bacterial magnetic nanoparticles

The biomineralized bacterial magnetic nanoparticles (BMPs) have been widely studied for biomedical applications with their magnetic properties and a layer of biomembrane. Herein, BMPs were firstly used for magnetically targeted photothermal cancer therapy in vivo. A self-build C-shaped bipolar permanent magnet was used for magnetic targeting though the generation of a high gradient magnetic field within a small target area. For in vitro simulated experiment, BMPs had a high retention rate in magnetically targeted region with different flow rates. In H22 tumor bearing mice, the magnetic targeting induced a 40% increase of BMPs retention in tumor tissues. In vivo photothermal therapy with 808 nm laser irradiation could induce a complete tumor elimination with magnetic targeting. These results indicated that the systematically administrated BMPs with magnetic targeting would be promising for photothermal cancer therapy.

Photosensitiser-gold nanoparticle conjugates for photodynamic therapy of cancer

Gold nanoparticles (AuNPs) have been extensively studied within biomedicine due to their biocompatibility and low toxicity. In particular, AuNPs have been widely used to deliver photosensitiser agents for photodynamic therapy (PDT) of cancer. Here we review the state-of-the-art for the functionalisation of the gold nanoparticle surface with both photosensitisers and targeting ligands for the active targeting of cancer cell surface receptors. From the initial use of the AuNPs as a simple carrier of the photosensitiser for PDT, the field has significantly advanced to include: the use of PEGylated modification to provide aqueous compatibility and stealth properties for in vivo use; gold metal-surface enhanced singlet oxygen generation; functionalisation of the AuNP surface with biological ligands to specifically target over-expressed receptors on the surface of cancer cells and; the creation of nanorods and nanostars to enable combined PDT and photothermal therapies. These versatile AuNPs have significantly enhanced the efficacy of traditional photosensitisers for both in vitro and in vivo cancer therapy. From this review it is apparent that AuNPs have an important future in the treatment of cancer.

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.