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

Oxidized cellulose-filled double thermo/pH-sensitive hydrogel for local chemo-photothermal therapy in breast cancer

Lumpectomy plus radiation is a treatment option offering better survival than conventional mastectomy for patients with early-stage breast cancer. However, successive radioactive therapy remains tedious and unsafe with severe adverse reactions and secondary injury. Herein, a composite hydrogel with pH- and photothermal double-sensitive activity is developed via physical crosslinking. The composite hydrogel incorporated with tempo-oxidized cellulose nanofiber (TOCN), polyvinyl alcohol (PVA) and a polydopamine (PDA) coating for photothermal therapy (PTT) triggered in situ release of doxorubicin (DOX) drug was utilized to optimize postoperative strategies of malignant tumors inhibition. The incorporation of TOCN significantly affects the performance of composite hydrogels. The best-performing TOCN/PVA7 was selected for drug loading and polydopamine coating by rational design. In vitro studies have demonstrated that the composite hydrogel exhibited high NIR photothermal conversion efficiency, benign cytotoxicity to L929 cells, pH-dependent release profiles, and strong MCF-7 cell inhibitory effects. Then the TOCN/PVA7-PDA@DOX hydrogel is implanted into the tumor resection cavity for local in vivo chemo-photothermal synergistical therapy to ablate residue tumor tissues. Overall, this work suggests that such a chemo-photothermal hydrogel delivery system has great potential as a promising tool for the postsurgical management of breast cancer.

Recent advances in photothermal nanomaterials-mediated detection of circulating tumor cells

Photothermal materials have shown great potential for cancer detection and treatment due to their excellent photothermal effects. Circulating tumor cells (CTCs) are tumor cells that are shed from the primary tumor into the blood and metastasize. In contrast to other tumor markers that are free in the blood, CTCs are a collective term for all types of tumor cells present in the peripheral blood, a source of tumor metastasis, and clear evidence of tumor presence. CTCs detection enables early detection, diagnosis and treatment of tumors, and plays an important role in cancer prevention and treatment. This review summarizes the application of various photothermal materials in CTC detection, including gold, carbon, molybdenum, phosphorus, etc. and describes the significance of CTC detection for early tumor diagnosis and tumor prognosis. Focus is also put on how various photothermal materials play their roles in CTCs detection, including CT, imaging and photoacoustic and therapeutic roles. The physicochemical properties, shapes, and photothermal properties of various photothermal materials are discussed to improve the detection sensitivity and efficiency and to reduce the damage to normal cells. These photothermal materials are capable of converting radiant light energy into thermal energy for highly-sensitive CTCs detection and improving their photothermal properties by various methods, and have achieved good results in various experiments. The use of photothermal materials for CTCs detection is becoming more and more widespread and can be of significant help in early cancer screening and later treatment.

Advances in screening hyperthermic nanomedicines in 3D tumor models

Hyperthermic nanomedicines are particularly relevant for tackling human cancer, providing a valuable alternative to conventional therapeutics. The early-stage preclinical performance evaluation of such anti-cancer treatments is conventionally performed in flat 2D cell cultures that do not mimic the volumetric heat transfer occurring in human tumors. Recently, improvements in bioengineered 3D in vitro models have unlocked the opportunity to recapitulate major tumor microenvironment hallmarks and generate highly informative readouts that can contribute to accelerating the discovery and validation of efficient hyperthermic treatments. Leveraging on this, herein we aim to showcase the potential of engineered physiomimetic 3D tumor models for evaluating the preclinical efficacy of hyperthermic nanomedicines, featuring the main advantages and design considerations under diverse testing scenarios. The most recent applications of 3D tumor models for screening photo- and/or magnetic nanomedicines will be discussed, either as standalone systems or in combinatorial approaches with other anti-cancer therapeutics. We envision that breakthroughs toward developing multi-functional 3D platforms for hyperthermia onset and follow-up will contribute to a more expedited discovery of top-performing hyperthermic therapies in a preclinical setting before their in vivo screening.

Fabrication of Yolk-Shell Structure with Multifarious Nanoparticles via Double-Layered Encapsulation Strategy

The post-encapsulation method (such as single-layered encapsulation) is a promising strategy to synthesize yolk-shell structures that protect functional nanoparticles by the molecular sieving effect. However, this method exhibited limited loading capacity and nonuniform encapsulation during the co-encapsulation of various nanoparticles owing to the insufficient surface area for nanoparticle attachment. To address these limitations, we proposed a double-layered encapsulation method comprising an increased number of silica template layers and separate attachment of multifarious nanoparticles to different layers. Compared with conventional methods, this strategy can precisely adjust the ratio of encapsulated nanoparticles and increase the loading amount, which improves the functionality of yolk-shell structures, such as the photothermal properties of gold nanoparticle-encapsulated yolk-shell structures (∼69%). We describe, for the first time, the precise control of the ratio of encapsulated nanoparticles and the loading of numerous nanoparticles. Consequently, this strategy has significant potential for various applications of yolk-shell structures.

Gold nanostructure-mediated delivery of anticancer agents: Biomedical applications, reversing drug resistance, and stimuli-responsive nanocarriers

The application of nanoarchitectures in cancer therapy seems to be beneficial for the delivery of antitumor drugs. In recent years, attempts have been made to reverse drug resistance, one of the factors threatening the lives of cancer patients worldwide. Gold nanoparticles (GNPs) are metal nanostructures with a variety of advantageous properties, such as tunable size and shape, continuous release of chemicals, and simple surface modification. This review focuses on the application of GNPs for the delivery of chemotherapy agents in cancer therapy. Utilizing GNPs results in targeted delivery and increased intracellular accumulation. Besides, GNPs can provide a platform for the co-delivery of anticancer agents and genetic tools with chemotherapeutic compounds to exert a synergistic impact. Furthermore, GNPs can promote oxidative damage and apoptosis by triggering chemosensitivity. Due to their capacity for providing photothermal therapy, GNPs can enhance the cytotoxicity of chemotherapeutic agents against tumor cells. The pH-, redox-, and light-responsive GNPs are beneficial for drug release at the tumor site. For the selective targeting of cancer cells, surface modification of GNPs with ligands has been performed. In addition to improving cytotoxicity, GNPs can prevent the development of drug resistance in tumor cells by facilitating prolonged release and loading low concentrations of chemotherapeutics while maintaining their high antitumor activity. As described in this study, the clinical use of chemotherapeutic drug-loaded GNPs is contingent on enhancing their biocompatibility.

Research Progress of Photothermal Nanomaterials in Multimodal Tumor Therapy

The aggressive growth of cancer cells brings extreme challenges to cancer therapy while triggering the exploration of the application of multimodal therapy methods. Multimodal tumor therapy based on photothermal nanomaterials is a new technology to realize tumor cell thermal ablation through near-infrared light irradiation with a specific wavelength, which has the advantages of high efficiency, less adverse reactions, and effective inhibition of tumor metastasis compared with traditional treatment methods such as surgical resection, chemotherapy, and radiotherapy. Photothermal nanomaterials have gained increasing interest due to their potential applications, remarkable properties, and advantages for tumor therapy. In this review, recent advances and the common applications of photothermal nanomaterials in multimodal tumor therapy are summarized, with a focus on the different types of photothermal nanomaterials and their application in multimodal tumor therapy. Moreover, the challenges and future applications have also been speculated.

Doxorubicin-encapsulated thermosensitive liposome-functionalized photothermal composite scaffolds for synergistic photothermal therapy and chemotherapy

Synergistic therapy, especially the combination of photothermal therapy and chemotherapy, has been proposed as an effective therapeutic approach for breast cancer treatment. In this study, a smart platform for synergistic photothermal therapy and chemotherapy was developed by hybridizing doxorubicin-encapsulated thermosensitive liposomes and gold nanorods into porous scaffolds of gelatin and polyglutamic acid (Dox-lipo/AuNR/Gel/PGA). The Dox-lipo/AuNR/Gel/PGA composite scaffolds had good photothermal conversion and temperature-dependent doxorubicin release properties. Under near-infrared laser irradiation, the composite scaffolds increased the local temperature to not only kill the breast cancer cells in the scaffolds but also accelerate the release of doxorubicin to eliminate the breast cancer cells surrounding the scaffolds. In vitro cell culture and in vivo mouse experiments demonstrated that the synergistic effects of photothermal ablation combined with doxorubicin-induced inhibition of the breast cancer cells in and surrounding the composite scaffolds under near-infrared laser irradiation. Moreover, after drug release was complete, the composite scaffolds fostered human bone marrow-derived mesenchymal stem cell proliferation. These results suggested that the composite scaffolds provided synergistic photothermal therapy and chemotherapy for breast cancer cell elimination at the early stage and promoted stem cell activities at the late stage. Therefore, this composite scaffold holds great potential as a synergistic therapy platform for breast cancer treatment.

Inhibitory Effect of Etravirine, a Non-Nucleoside Reverse Transcriptase Inhibitor, via Anterior Gradient Protein 2 Homolog Degradation against Ovarian Cancer Metastasis

Anterior gradient protein 2 homolog (AGR2), an endoplasmic reticulum protein, is secreted in the tumor microenvironment. AGR2 is a member of the disulfide isomerase family, is highly expressed in multiple cancers, and promotes cancer metastasis. In this study, we found that etravirine, which is a non-nucleoside reverse transcriptase inhibitor, could induce AGR2 degradation via autophagy. Moreover, etravirine diminished proliferation, migration, and invasion in vitro. Moreover, in an orthotopic xenograft mouse model, the combination of etravirine and paclitaxel significantly suppressed cancer progression and metastasis. This drug may be a promising therapeutic agent for the treatment of ovarian cancer.