NIR light-triggered nanomaterials-based prodrug activation towards cancer therapy

Nano-Proteolysis Targeting Chimeras (Nano-PROTACs) in Cancer Therapy

Proteolysis-targeting chimeras (PROTACs) are heterobifunctional molecules that have the capability to induce specific protein degradation. While playing a revolutionary role in effectively degrading the protein of interest (POI), PROTACs encounter certain limitations that impede their clinical translation. These limitations encompass off-target effects, inadequate cell membrane permeability, and the hook effect. The advent of nanotechnology presents a promising avenue to surmount the challenges associated with conventional PROTACs. The utilization of nano-proteolysis targeting chimeras (nano-PROTACs) holds the potential to enhance specific tissue accumulation, augment membrane permeability, and enable controlled release. Consequently, this approach has the capacity to significantly enhance the controllable degradation of target proteins. Additionally, they enable a synergistic effect by combining with other therapeutic strategies. This review comprehensively summarizes the structural basis, advantages, and limitations of PROTACs. Furthermore, it highlights the latest advancements in nanosystems engineered for delivering PROTACs, as well as the development of nano-sized PROTACs employing nanocarriers as linkers. Moreover, it delves into the underlying principles of nanotechnology tailored specifically for PROTACs, alongside the current prospects of clinical research. In conclusion, the integration of nanotechnology into PROTACs harbors vast potential in enhancing the anti-tumor treatment response and expediting clinical translation.

Polysaccharide‑platinum complexes for cancer theranostics

Platinum anticancer drugs have been explored and developed in recent years to reduce systematic toxicities and resist drug resistance. Polysaccharides derived from nature have abundant structures as well as pharmacological activities. The review provides insights on the design, synthesis, characterization and associating therapeutic application of platinum complexes with polysaccharides that are classified by electronic charge. The complexes give birth to multifunctional properties with enhanced drug accumulation, improved tumor selectivity and achieved synergistic antitumor effect in cancer therapy. Several techniques developing polysaccharides-based carriers newly are also discussed. Moreover, the lasted immunoregulatory activities of innate immune reactions triggered by polysaccharides are summarized. Finally, we discuss the current shortcomings and outline potential strategies for improving platinum-based personalized cancer treatment. Using platinum-polysaccharides complexes for improving the immunotherapy efficiency represents a promising framework in future.

Coumarin-Based Fluorescent Inhibitors for Photocontrollable Bioactivation

Activation of the IRE-1/XBP-1 pathway is related to many human diseases. Coumarin-based derivatives acting as both IRE-1 inhibitors and bright fluorophores are highly desirable to establish an integrated fluorescent inhibitor system. Here, we take insights into the aqueous stability of a photocaged IRE-1 inhibitor PC-D-F07 through a structure activity relationship. The substituent effects indicate that the electron-withdrawing -NO₂ moiety in the photocage combined with the tricyclic coumarin fluorophore contribute to the structural stability of PC-D-F07. To optimize the photocage of PC-D-F07, we incorporate a 1-ethyl-2-nitrobenzyl or 2-nitrobenzyl photolabile moiety on the hydroxyl group of the IRE-1 inhibitor to generate RF-7 and RF-8. Upon photoactivation, both RF-7 and RF-8 present an increased fluorescence response, sequentially enabling the unlocking of the ortho-1,3-dioxane acetal for the release of active IRE-1 inhibitors. Moreover, RF-7 exhibits a high repolarization ratio of converting M2-type tumor-associated macrophages (M2-TAMs) to M1-type immune-responsive macrophages. This provides a novel prodrug strategy of modulating druggable fluorophore backbones to achieve spatiotemporally controllable drug release for precise cancer treatment.

Nanomaterial-mediated low-temperature photothermal therapy via heat shock protein inhibition

With the continuous development of nanobiotechnology in recent years, combining photothermal materials with nanotechnology for tumor photothermal therapy (PTT) has drawn many attentions nanomedicine research. Although nanomaterial-mediated PTT is more specific and targeted than traditional treatment modalities, hyperthermia can also damage normal cells. Therefore, researchers have proposed the concept of low-temperature PTT, in which the expression of heat shock proteins (HSPs) is inhibited. In this article, the research strategies proposed in recent years based on the inhibition of HSPs expression to achieve low-temperature PTT was reviewed. Folowing this, the synthesis, properties, and applications of these nanomaterials were introduced. In addition, we also summarized the problems of nanomaterial-mediated low-temperature PTT at this stage and provided an outlook on future research directions.

Preparation and application of pH-responsive drug delivery systems

Microenvironment-responsive drug delivery systems (DDSs) can achieve targeted drug delivery, reduce drug side effects and improve drug efficacies. Among them, pH-responsive DDSs have gained popularity since the pH in the diseased tissues such as cancer, bacterial infection and inflammation differs from a physiological pH of 7.4 and this difference could be harnessed for DDSs to release encapsulated drugs specifically to these diseased tissues. A variety of synthetic approaches have been developed to prepare pH-sensitive DDSs, including introduction of a variety of pH-sensitive chemical bonds or protonated/deprotonated chemical groups. A myriad of nano DDSs have been explored to be pH-responsive, including liposomes, micelles, hydrogels, dendritic macromolecules and organic-inorganic hybrid nanoparticles, and micron level microspheres. The prodrugs from drug-loaded pH-sensitive nano DDSs have been applied in research on anticancer therapy and diagnosis of cancer, inflammation, antibacterial infection, and neurological diseases. We have systematically summarized synthesis strategies of pH-stimulating DDSs, illustrated commonly used and recently developed nanocarriers for these DDSs and covered their potential in different biomedical applications, which may spark new ideas for the development and application of pH-sensitive nano DDSs.

Series of High Magnetic Resonance-Guided Photoinduced Nanodelivery Systems for Precisely Improving the Efficiency of Cancer Therapy

Nanochemotherapy is recognized as one of the most promising cancer treatment options, and the design of the carrier has a crucial impact on the final efficacy. To precisely improve the efficacy and reduce the toxicity, we combined the clinical contrast agent (Gd-DTPA) with a stimulus-sensitive o-nitrobenzyl ester and then prepared a series of nNBGD lipids by varying the carbon chain length of the hydrophobic group. The self-assembled nNBGD liposomes can be tracked by MRI to localize the aggregation of drug carriers in vivo, so as to prompt the application of light stimulation at the optimal time to facilitate the precise release of carriers at the lesion site. And the application potential of this strategy was verified with 88% tumor suppression effect in the 12NBGD-DOX+UV group. In addition, this paper emphasizes that small differences in structure can affect the overall performance of the carriers. By exploration of the differences in stability, drug loading, stimulus responsiveness, MRI imaging effect, and toxicity of the series of nNBGD carriers, the relationship between the length of the hydrophobic group of nNBGD lipids and the overall performance of the carriers is given, which provides experimental support and design reference for other carriers.

DNA Logic Circuits for Cancer Theranostics

Cancer diagnosis and therapeutics (theranostics) based on the tumor microenvironment (TME) and biomarkers has been an emerging approach for precision medicine. DNA nanotechnology dynamically controls the self-assembly of DNA molecules at the nanometer scale to construct intelligent DNA chemical reaction systems. The DNA logic circuit is a particularly emerging approach for computing within the DNA chemical systems. DNA logic circuits can sensitively respond to tumor-specific markers and the TME through logic operations and signal amplification, to generate detectable signals or to release anti-cancer agents. In this review, the fundamental concepts of DNA logic circuits are clarified, the basic modules in the circuit are summarized, and how this advanced nano-assembly circuit responds to tumor-related molecules, how to perform logic operations, to realize signal amplification, and selectively release drugs through discussing over 30 application examples, are demonstrated. This review shows that DNA logic circuits have powerful logic judgment and signal amplification functions in improving the specificity and sensitivity of cancer diagnosis and making cancer treatment controllable. In the future, researchers are expected to overcome the existing shortcomings of DNA logic circuits and design smarter DNA devices with better biocompatibility and stability, which will further promote the development of cancer theranostics.

Photodynamic Therapy in Combination with Chemotherapy, Targeted, and Immunotherapy As a Successful Therapeutic Approach for Advanced Gastric Adenocarcinoma: A Case Report and Literature Review

Objective: To explore the efficacy of photodynamic therapy combined with chemotherapy, targeted therapy, and immunotherapy in poorly differentiated gastric adenocarcinoma (GAC). Background: Advanced GAC has high malignancy and mortality rate. To date, no study has applied photodynamic treatment (PDT) combined with chemo-, targeted, and immunotherapy to treat this cancer. Patient and methods: Clinical data of a patient diagnosed with poorly differentiated GAC admitted to the department of oncology of the Lanzhou University Second Hospital were retrospectively analyzed. The patient underwent four PDT procedures combined with chemo-, targeted, and immunotherapy. Results: A 72-year-old male patient received combination therapy of PDT. This treatment resolved the cancerous tissues and levels of tumor markers. There was no recurrence and metastasis during a 7-month follow-up. Conclusions: Combination therapy of PDT can effectively treat tumors and may be a method suitable for elderly patients with advanced GAC.

Tumor microenvironment pH-responsive pentagonal gold prism-based nanoplatform for multimodal imaging and combined therapy of castration-resistant prostate cancer

Given that there is lack of effective therapies for castration-resistant prostate cancer (CRPC), the combination of photothermal (PTT), photodynamic (PDT), and chemical therapy (CT) has emerged as a prominent strategy. Tumor-targeted delivery and controlled release of antitumor drug are key-elements of any combined therapy. Considering these important elements, we designed and constructed tumor microenvironment (TME)-activated nanoprobes (PGP/CaCO₃@IR820/DTX-HA). The CaCO₃ shell could efficiently entrap the photosensitizer IR820 and the chemotherapeutic docetaxel (DTX) on the surface of pentagonal gold prisms (PGPs) to prevent elimination from the circulation, and it could act as a TME-trigger to achieve TME-responsive drug release. After modification with hyaluronic acid, PGP/CaCO₃@IR820/DTX-HA was capable of synergistic TME-triggered PTT/PDT/CT and tumor-targeted delivery. Our in vitro and in vivo studies demonstrate that PGP/CaCO₃@IR820/DTX-HA could achieve synergistic antitumor effects following near-infrared (NIR)-light irradiation. In addition, using the NIR fluorescence signal from IR820 and the photoacoustic (PA) signal from PGPs, i.e., through multimodal fluorescence/photoacoustic imaging, we could monitor the in vivo distribution and excretion of PGP/CaCO₃@IR820/DTX-HA. Therefore, it can be concluded that PGP/CaCO₃@IR820/DTX-HA shows promising clinical translational potential as a treatment for CRPC. STATEMENT OF SIGNIFICANCE: Utilizing pentagonal gold prisms (PGPs), we constructed a multifunctional nanoplatform (PGP/CaCO₃@IR820/DTX-HA) for effectively delivering agents into the tumor microenvironment (TME) for the diagnosis and therapy of castration-resistant prostate cancer (CRPC). The synthetic nanoplatform can satisfy TME-activated synergistic photothermal therapy (PTT)/photodynamic therapy (PDT)/chemical therapy (CT) and NIR fluorescence imaging/photoacoustic (PA) imaging. Hyaluronic acid (HA) on the surface of nanoplatform allowed the specific tumor-targeting capacity and biocompatibility. In conclusion, PGP/CaCO₃@IR820/DTX-HA could be a promising integrated nanoplatform for CRPC diagnosis and treatment.

Photodynamic Therapy for Pancreatic Ductal Adenocarcinoma

Simple Summary

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal of human cancers. Numerous clinical trials evaluating various combinations of chemotherapy and targeted agents and radiotherapy have failed to provide meaningful improvements in survival. A growing number of studies however have indicated that photodynamic therapy (PDT) may be a viable approach for treatment of some pancreatic tumors. PDT, which uses light to activate a photosensitizing agent in target tissue, has seen widespread adoption primarily for dermatological and other applications where superficial light delivery is relatively straightforward. Advances in fiber optic light delivery and dosimetry however have been leveraged to enable PDT even for challenging internal sites, including the pancreas. The aim of this article is to help inform future directions by reviewing relevant literature on the basic science, current clinical status, and potential challenges in the development of PDT as a treatment for PDAC.

Abstract

Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal of human cancers. Clinical trials of various chemotherapy, radiotherapy, targeted agents and combination strategies have generally failed to provide meaningful improvement in survival for patients with unresectable disease. Photodynamic therapy (PDT) is a photochemistry-based approach that enables selective cell killing using tumor-localizing agents activated by visible or near-infrared light. In recent years, clinical studies have demonstrated the technical feasibility of PDT for patients with locally advanced PDAC while a growing body of preclinical literature has shown that PDT can overcome drug resistance and target problematic and aggressive disease. Emerging evidence also suggests the ability of PDT to target PDAC stroma, which is known to act as both a barrier to drug delivery and a tumor-promoting signaling partner. Here, we review the literature which indicates an emergent role of PDT in clinical management of PDAC, including the potential for combination with other targeted agents and RNA medicine.

Indocyanine Green-Based Theranostic Nanoplatform for NIR Fluorescence Image-Guided Chemo/Photothermal Therapy of Cervical Cancer

Purpose

Indocyanine green (ICG) is a favorable fluorescence nanoprobe for its strong NIR-I fluorescence emission and good photothermal capabilities. However, the stability and tumor targeting ability of ICG is poor, which limits its further applications. To further improve the photothermal and therapeutic efficiency of ICG, bovine serum albumin (BSA) was utilized to encapsulate the ICG and the chemotherapeutic drug doxorubicin (DOX) was loaded to form the BSA@ICG-DOX theranostic nanoplatform.

Methods

In this study, ICG-loaded BSA nanoparticles (NPs) and the BSA@ICG-DOX NPs were fabricated using reprecipitation methods. Next, the tumour inhibition ability and biocompatibility of the NPs were evaluated. A subcutaneous xenografted nude mice model was established and imaging guided synergetic therapy was performed with the assistance of BSA@ICG-DOX NPs under 808 nm laser irradiation.

Results

The BSA@ICG NPs exhibited strong NIR-I fluorescence emission, excellent photothermal properties, biocompatibility, and tumor targeting ability. To further improve the therapeutic efficiency, the chemotherapeutic drug doxorubicin (DOX) was loaded into the BSA@ICG NPs to form the BSA@ICG-DOX theranostic nanoplatform. The BSA@ICG-DOX NPs were spherical with an average size of ~194.7 nm. The NPs had high encapsulation efficiency (DOX: 19.96% and ICG: 60.57%), and drug loading content (DOX: 0.95% and ICG: 3.03%). Next, excellent NIR-I fluorescence and low toxicity of the BSA@ICG-DOX NPs were verified. Targeted NIR-I fluorescence images were obtained after intravenous injection of the NPs into the subcutaneous cervical tumors of the mice.

Conclusion

To improve the anti-tumor efficiency of the ICG@BSA NPs, the chemotherapeutic drug DOX was loaded into the BSA@ICG NPs. The NIR excitation/emission and targeted BSA@ICG-DOX NPs enables high-performance diagnosis and chemo/photothermal therapy of subcutaneous cervical tumors, providing a promising approach for further biomedical applications.

A Photoresponsive Nanozyme for Synergistic Catalytic Therapy and Dual Phototherapy

Dual phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), has shown a great prospect in cancer treatment. However, its therapeutic effect is restricted by the depth of light penetration in tissue and tumor hypoxia environment. Herein, inspired by the specific response of nanozymes to the tumor microenvironment (TME), a simple and versatile nanozyme-mediated synergistic dual phototherapy nanoplatform (denoted as FePc/HNCSs) is constructed using hollow nitrogen-doped carbon nanospheres (HNCSs) and iron phthalocyanine (FePc). FePc/HNCSs simultaneously exhibit peroxidase (POD)- and catalase (CAT)-like activities, which not only can convert endogenous hydrogen peroxide (H₂ O₂ ) into highly toxic hydroxyl radicals (•OH) for catalytic therapy, but also decompose H₂ O₂ to oxygen (O₂ ) to enhance O₂ -dependent PDT. In addition, their enzyme-like activities are significantly enhanced under light irradiation. Combining with the excellent photothermal effect, FePc/HNCSs realize a high tumor inhibition rate of 96.3%. This strategy opens a new horizon for exploring a more powerful tumor treatment nanoplatform.

Photosensitizer Nanoparticles Boost Photodynamic Therapy for Pancreatic Cancer Treatment

Patients with pancreatic cancer (PCa) have a poor prognosis apart from the few suitable for surgery. Photodynamic therapy (PDT) is a minimally invasive treatment modality whose efficacy and safety in treating unresectable localized PCa have been corroborated in clinic. Yet, it suffers from certain limitations during clinical exploitation, including insufficient photosensitizers (PSs) delivery, tumor-oxygenation dependency, and treatment escape of aggressive tumors. To overcome these obstacles, an increasing number of researchers are currently on a quest to develop photosensitizer nanoparticles (NPs) by the use of a variety of nanocarrier systems to improve cellular uptake and biodistribution of photosensitizers. Encapsulation of PSs with NPs endows them significantly higher accumulation within PCa tumors due to the increased solubility and stability in blood circulation. A number of approaches have been explored to produce NPs co-delivering multi-agents affording PDT-based synergistic therapies for improved response rates and durability of response after treatment. This review provides an overview of available data regarding the design, methodology, and oncological outcome of the innovative NPs-based PDT of PCa.