Folate-mediated and pH-responsive chidamide-bound micelles encapsulating photosensitizers for tumor-targeting photodynamic therapy

Advancements in Functional Nanomaterials Inspired by Viral Particles

Virus-like particles (VLPs) are nanostructures composed of one or more structural proteins, exhibiting stable and symmetrical structures. Their precise compositions and dimensions provide versatile opportunities for modifications, enhancing their functionality. Consequently, VLP-based nanomaterials have gained widespread adoption across diverse domains. This review focuses on three key aspects: the mechanisms of viral capsid protein self-assembly into VLPs, design methods for constructing multifunctional VLPs, and strategies for synthesizing multidimensional nanomaterials using VLPs. It provides a comprehensive overview of the advancements in virus-inspired functional nanomaterials, encompassing VLP assembly, functionalization, and the synthesis of multidimensional nanomaterials. Additionally, this review explores future directions, opportunities, and challenges in the field of VLP-based nanomaterials, aiming to shed light on potential advancements and prospects in this exciting area of research.

A dual-prodrug nanogel combining Vorinostat and Pyropheophorbide a for a high efficient photochemotherapy

The challenges posed by intractable relapse and metastasis in cancer treatment have led to the development of various forms of photodynamic therapy (PDT). However, traditional drug delivery systems, such as virus vectors, liposomes, and polymers, often suffer from issues like desynchronized drug release, carrier instability, and drug leakage during circulation. To address these problems, we have developed a dual-prodrug nanogel (PVBN) consisting of Pyro (Pyropheophorbide a) and SAHA (Vorinostat) bound to BSA (Bovine Serum Albumin), which facilitates synchronous and spontaneous drug release in situ within the lysosome. Detailed results indicate that PVBN-treated tumor cells exhibit elevated levels of ROS and Acetyl-H3, leading to necrosis, apoptosis, and cell cycle arrest, with PDT playing a dominant role in the synergistic therapeutic effect. Furthermore, the anti-tumor efficacy of PVBN was validated in melanoma-bearing mice, where it significantly inhibited tumor growth and pulmonary metastasis. Overall, our dual-prodrug nanogel, formed by the binding of SAHA and Pyro to BSA and releasing drugs within the lysosome, represents a novel and promising strategy for enhancing the clinical efficacy of photochemotherapy.

A nanocomposite competent to overcome cascade drug resistance in ovarian cancer via mitochondria dysfunction and NO gas synergistic therapy

Ovarian cancer (OC) is one of the most common and recurring malignancies in gynecology. Patients with relapsed OC always develop "cascade drug resistance" (CDR) under repeated chemotherapy, leading to subsequent failure of chemotherapy. To overcome this challenge, amphiphiles (P1) carrying a nitric oxide (NO) donor (Isosorbide 5-mononitrate, ISMN) and high-density disulfide are synthesized for encapsulating mitochondria-targeted tetravalent platinum prodrug (TPt) to construct a nanocomposite (INP@TPt). Mechanism studies indicated that INP@TPt significantly inhibited drug-resistant cells by increasing cellular uptake and mitochondrial accumulation of platinum, depleting glutathione, and preventing apoptosis escape through generating highly toxic peroxynitrite anion (ONOO-). To better replicate the microenvironmental and histological characteristics of the drug resistant primary tumor, an OC patient-derived tumor xenograft (PDXOC) model in BALB/c nude mice was established. INP@TPt showed the best therapeutic effects in the PDXOC model. The corresponding tumor tissues contained high ONOO- levels, which were attributed to the simultaneous release of O2•- and NO in tumor tissues. Taken together, INP@TPt-based systematic strategy showed considerable potential and satisfactory biocompatibility in overcoming platinum CDR, providing practical applications for ovarian therapy.

Tracking intracellular nuclear targeted-chemotherapy of chidamide-loaded Prussian blue nanocarriers by SERS mapping

The novel histone deacetylase drug chidamide (CHI) has been proven to regulate gene expression associated with oncogenesis via epigenetic mechanisms. However, huge side effects such as non-targeting, poor intracellular accumulation and low nuclear entry efficiency severely restrict its therapeutic efficacy. Dual-targeted nanodrug delivery systems have been proposed as the solution. Herein, we developed a CHI-loaded drug delivery nanosystem based on Prussian blue (PB) nanocarrier, which combines surface-enhanced Raman scattering (SERS) tracking function with cancer cell/nuclear-targeted chemotherapy capability. With the property of background-free SERS mapping, PB nanocarriers can serve as tracking agents to localize intracellular CHI. The incorporation of targeted molecules specifically enhances the cancer cell/nuclear internalization and chemotherapeutic effects of CHI-loaded PB nanocarriers. In vitro cytotoxicity assay clearly shows that the constructed CHI-loaded PB nanocarriers have significant inhibitory on Jurkat cell proliferation. Furthermore, SERS spectral analysis of Jurkat cells incubated with the CHI-loaded PB nanocarriers reveals obvious features of cellular apoptosis: DNA skeleton fragmentation, chromatin depolymerization, histone acetylation, and nucleosome conformation change. Importantly, this CHI-loaded PB nanocarrier will provide a new insight for lymphoblastic leukemia targeted chemotherapy.

Combinational photodynamic and photothermal - based therapies for melanoma in mouse models

BACKGROUND

Melanoma is a highly metastatic skin cancer with limited response to current therapies in advanced patients. To overcome resistance, novel treatments based on photodynamic and photothermal therapies (PDT and PTT, respectively) have been developed to treat melanoma in preclinical murine models. Despite success inhibiting implanted tumors' growth, there has been limited evaluation of their long-term effectiveness in preventing metastasis, recurrence, or improving survival rates.

METHODS

Combined and multidrug therapies based on PDT and/or PTT to treat cutaneous malignant melanoma in the preclinical mouse model were reviewed from 2016 onwards. PubMed® was the database in which the search was performed using mesh search algorithms resulting in fifty-one studies that comply with strict inclusion rules of screening.

RESULTS

B16 melanoma-bearing C57BLACK6 mice model was the most used to evaluate immunotherapies, chemotherapies, and targeted therapies in combination with PDT and/or PTT. Combined therapies demonstrated a synergistic effect, resulting in intense antitumor activity. The most extensively studied protocol for developing metastatic models involved the intravenous administration of malignant cells, with some combined therapies being tested. Furthermore, the review presents the composition of the nanostructures utilized for delivering the drugs and light-responsive agents and the treatment plans for each combined approach.

CONCLUSIONS

The identified mechanisms to simulate metastatic melanoma models and the therapeutic combinations may aid in evaluating the systemic protection of combined PDT and PTT-based therapies, particularly in conducting short-term preclinical experiments. Such simulations could have relevance to clinical studies.

Enabling In Vivo Optical Imaging of an Osmium Photosensitizer by Micellar Formulation

Osmium (Os)-based photosensitizers (PSs) exhibit unique broad, red-shifted absorption, favoring PDT activity at greater tissue depths. We recently reported on a potent Os(II) PS, rac-[Os(phen)2(IP-4T)](Cl)2 (ML18J03) with submicromolar hypoxia activity. ML18J03 exhibits a low luminescence quantum yield of 9.8 × 10-5 in PBS, which limits its capacity for in vivo luminescence imaging. We recently showed that formulating ML18J03 into 10.2 nm DSPE-mPEG2000 micelles (Mic-ML18J03) increases its luminescence quantum yield by two orders of magnitude. Here, we demonstrate that Mic-ML18J03 exhibits 47-fold improved accumulative luminescence signals in orthotopic AT-84 head and neck tumors. We show, for the first time, that micellar formulation provides up to 11.7-fold tumor selectivity for ML18J03. Furthermore, Mic-ML18J03 does not experience the concentration-dependent quenching observed with unformulated ML18J03 in PBS, and formulation reduces spectral shifting of the emission maxima during PDT (variance = 6.5 and 27.3, respectively). The Mic-ML18J03 formulation also increases the production of reactive molecular species 2-3-fold. These findings demonstrate that micellar formulation is a versatile and effective approach to enable in vivo luminescence imaging options for an otherwise quenched, yet promising, PS.

Synergetic delivery of artesunate and isosorbide 5-mononitrate with reduction-sensitive polymer nanoparticles for ovarian cancer chemotherapy

Ovarian cancer is a highly fatal gynecologic malignancy worldwide. Chemotherapy remains the primary modality both for primary and maintenance treatments of ovarian cancer. However, the progress in developing chemotherapeutic agents for ovarian cancer has been slow in the past 20 years. Thus, new and effective chemotherapeutic drugs are urgently needed for ovarian cancer treatment. A reduction-responsive synergetic delivery strategy (PSSP@ART-ISMN) with co-delivery of artesunate and isosorbide 5-mononitrate was investigated in this research study. PSSP@ART-ISMN had various effects on tumor cells, such as (i) inducing the production of reactive oxygen species (ROS), which contributes to mitochondrial damage; (ii) providing nitric oxide and ROS for the tumor cells, which further react to generate highly toxic reactive nitrogen species (RNS) and cause DNA damage; and (iii) arresting cell cycle at the G0/G1 phase and inducing apoptosis. PSSP@ART-ISMN also demonstrated excellent antitumor activity with good biocompatibility in vivo. Taken together, the results of this work provide a potential delivery strategy for chemotherapy in ovarian cancer.

Chidamide stacked in magnetic polypyrrole nano-composites counter thermotolerance and metastasis for visualized cancer photothermal therapy

Photothermal therapy (PTT) has become one of the most promising therapies in cancer treatment as its noninvasiveness, high selectivity, and favorable compliance in clinic. However, tumor thermotolerance and distal metastasis reduce its efficacy, becoming the bottleneck of applying PTT in clinic. In this study, a chidamide-loaded magnetic polypyrrole nanocomposite (CMPP) has been fabricated as a visualized cancer photothermal agent (PTA) to counter tumor thermotolerance and metastasis. The efficacy of CMPP was characterized by in vitro and in vivo assays. As a result, this kind of magnetic polypyrrole nanocomposites were black spherical nanoparticles, possessing a favorable photothermal effect and the suitable particle size of 176.97 ± 1.45 nm with a chidamide loading rate of 12.92 ± 0.45%. Besides, comparing with PTT, CMPP exhibited significantly higher cytotoxicity and cellular apoptosis rate in two tumor cell lines (B16-F10 and HepG2). In vivo study, the mice showed obvious near-infrared (NIR) and magnetic resonance imaging (MRI) dual-modal imaging at tumor sites and sentinel lymph nodes (SLNs); on the other hand, magnetic targeting guided CMPP achieved a cure level on melanoma-bearing mice through preventing metastasis and thermotolerance. Overall, with high loading efficiency of chidamide and strong magnetic targeting to tumor sites and SLNs, CMPP could significantly raise efficiency of PTT by targeting tumor thermotolerance and metastasis, and this strategy may be exploited therapeutically to upgrade PTT with MPP as one of appropriate carriers for histone deacetylase inhibitors (HDACis).

pH-Responsive Polymer Nanomaterials for Tumor Therapy

The complexity of the tumor microenvironment presents significant challenges to cancer therapy, while providing opportunities for targeted drug delivery. Using characteristic signals of the tumor microenvironment, various stimuli-responsive drug delivery systems can be constructed for targeted drug delivery to tumor sites. Among these, the pH is frequently utilized, owing to the pH of the tumor microenvironment being lower than that of blood and healthy tissues. pH-responsive polymer carriers can improve the efficiency of drug delivery in vivo, allow targeted drug delivery, and reduce adverse drug reactions, enabling multifunctional and personalized treatment. pH-responsive polymers have gained increasing interest due to their advantageous properties and potential for applicability in tumor therapy. In this review, recent advances in, and common applications of, pH-responsive polymer nanomaterials for drug delivery in cancer therapy are summarized, with a focus on the different types of pH-responsive polymers. Moreover, the challenges and future applications in this field are prospected.

Dual-Emission Carbonized Polymer Dots for Ratiometric pH Sensing, pH-Dependent Generation of Singlet Oxygen, and Imaging-Guided Dynamics Monitoring of Photodynamic Therapy

The pH environment in cancer cells has been demonstrated to display vital influences on the therapeutic effect of photodynamic therapy (PDT). It is very interesting to develop pH-responsive probes for simultaneous pH sensing and dynamics monitoring of the effects of PDT, and therefore assessing the correlation between them. In this study, a multifunctional fluorescence probe, dual-emission carbonized polymer dot (CPD) in blue and red regions, which uses ethylene imine polymer (PEI) and 4,4',4″,4‴-(porphine-5, 10, 15, 20-tetrayl) tetrakis (benzoic acid) (TCPP) as precursors through a one-step hydrothermal amide reaction, has been designed for ratiometric pH sensing, generating pH-dependent ¹O₂ for PDT of cancer cells, and investigating the dynamics effects of PDT through pH-guided imaging. The prepared CPDs were successfully used for ratiometric pH response, pH-dependent generation of ¹O₂, and dynamics monitoring PDT in HeLa cells. This study may provide an alternative strategy to prepare CPD-based theranostic integrated nanoprobes for PDT through the rational design of precursors.

Progress of Photodynamic and RNAi Combination Therapy in Cancer Treatment

Photodynamic therapy (PDT) is a noninvasive and effective local treatment for cancers that produces selective damage to target tissues and cells. However, PDT alone is unlikely to completely inhibit tumor metastasis and/or local tumor recurrence. RNA interference (RNAi) is a phenomenon of gene silencing mediated by exogenous or endogenous double-stranded RNA (dsRNA). RNAi has entered a golden period of development, with the approval of four treatments employing RNAi. PDT in combination with RNAi therapy to inhibit related targets has been a research hotspot, with better clinical outcomes than monotherapy. In this review, the progress of PDT and small interfering RNA (siRNA) targeting different genes is discussed, while the achievements of the combined immunotherapy are reviewed.

A Review of Chemotherapy and Photodynamic Therapy for Lung Cancer Treatment

Cancer is among the leading causes of mortality and morbidity worldwide. Among the different types of cancers, lung cancer is considered to be the leading cause of death related to cancer and the most commonly diagnosed form of such disease. Chemotherapy remains a dominant treatment modality for many types of cancers at different stages. However, in many cases, cancer cells develop drug resistance and become nonresponsive to chemotherapy, thus, necessitating the exploration of alternative and /or complementary treatment modalities. Photodynamic Therapy (PDT) has emerged as an effective treatment modality for various malignant neoplasia and tumors. In PDT, the photochemical interaction of light, Photosensitizer (PS) and molecular oxygen produces Reactive Oxygen Species (ROS), which induces cell death. Combination therapy, by using PDT and chemotherapy, can promote synergistic effect against this fatal disease with the elimination of drug resistance, and enhancement of the efficacy of cancer eradication. In this review, we give an overview of chemotherapeutic modalities, PDT, and the different types of drugs associated with each therapy. Furthermore, we also explored the combined use of chemotherapy and PDT in the course of lung cancer treatment and how this approach could be the last resort for thousands of patients that have been diagnosed by this fatal disease.

Novel dual-mode antitumor chlorin-based derivatives as potent photosensitizers and histone deacetylase inhibitors for photodynamic therapy and chemotherapy

The combination of photodynamic therapy (PDT) and chemotherapy is a prospective strategy to improve antitumor efficacy. Herein, a series of novel cytotoxic chlorin-based derivatives as dual photosensitizers (PSs) and histone deacetylase inhibitors (HDACIs) were synthesized and investigated for biological activity. Among them, compound 15e showed definite HDAC2 and 10 inhibitory activities by up-regulating expression of acetyl-H4 and highest phototoxicity and dark-toxicity, which was more phototoxic than Talaporfin as a PS while with stronger dark-toxicity compared to vorinostat (SAHA) as a HDACI. The biological assays demonstrated that 15e was liable to enter A549 cells and localized in mitochondria, lysosomes, golgi and endoplasmic reticulum (ER) etc. multiple organelles, resulting in higher cell apoptosis rate and ROS production compared to Talaporfin. Moreover, it could induce tumor cell autophagy as a dual PS and HDACI. All results suggested that compound 15e could be applied as a potential dual cytotoxic drug for PDT and chemotherapy.

Light-activatable liposomes for repetitive on-demand drug release and immunopotentiation in hypoxic tumor therapy

External stimuli-responsive nanomedicine with desirable repetitive on-demand drug release character is postulated to greatly accommodate patients' flexible medication regime. To this object, light-activatable liposomes (Pt/Ce6-LP) integrated with both a Ce6 photodynamic component and a tetravalent platinum prodrug (Pt(IV)) chemotherapeutic component are engineered. This multifunctional system was rationally designed using unsaturated phospholipid to achieve repetitive on-demand drug release under discontinuous light irradiation, thus performing chemo-photodynamic therapy effect and immunopotentiation in hypoxic tumor. Furthermore, glutathione (GSH) consumption during transformation from Pt(IV) prodrug to Pt(II) can avoid depletion of reactive oxygen species (ROS) in photodynamic therapy (PDT). Note this positive feedback loop appears to remodel the redox balance of H₂O₂ and GSH in tumors, alleviating the hypoxic tumor microenvironment. The alleviated hypoxia is found to be critical to the enhancement of PDT efficacy, reversal of cisplatin resistance in tumors, and polarization of tumor-associated macrophages (TAMs) to the immunocompetent M1-phynotype. Pt/Ce6-LP with light radiation demonstrates significant antitumor effect and persistent post-medication inhibition in patient-derived tumor xenograft model of hepatocellular carcinoma.

Tumor Microenvironment-Responsive Nanomaterials as Targeted Delivery Carriers for Photodynamic Anticancer Therapy

Photodynamic therapy (PDT), as an alternative approach to treat tumors through reactive oxygen species (ROS) produced by the activated photosensitizers (PS) upon light irradiation, has attracted wide attention in recent years due to its low invasive and highly efficient features. However, the low hydrophilicity and poor targeting of PS limits the clinical application of PDT. Stimuli-responsive nanomaterials represent a major class of remarkable functional nanocarriers for drug delivery. In particular, tumor microenvironment-responsive nanomaterials (TMRNs) can respond to the special pathological microenvironment in tumor tissues to release the loaded drugs, that allows them to control the release of PS within tumor tissues. Recent studies have demonstrated that TMRNs can achieve the targeted release of PS at tumor sites, increase the concentration of PS in tumor tissues, and reduce side effects of PDT. Hence, in the present paper, we review TMRNs, mainly including pH-, redox-, enzymes-, and hypoxia-responsive smart nanomaterials, and focus on the application of these smart nanomaterials as targeted delivery carriers of PS in photodynamic anticancer therapy, to further boost the development of PDT in tumor therapy.

Combination Treatment of Cervical Cancer Using Folate-Decorated, pH-Sensitive, Carboplatin and Paclitaxel Co-Loaded Lipid-Polymer Hybrid Nanoparticles

PURPOSE

Cervical cancer is one of the most common causes of death among women globally. Combinations of cisplatin, paclitaxel, bevacizumab, carboplatin, topotecan, and gemcitabine are recommended as first-line therapies.

METHODS

This study focuses on the development of folate-decorated, pH-sensitive lipid-polymer hybrid nanoparticles (LPNs). Loading carboplatin (CBP) and paclitaxel (PTX), LPNs were expected to combine the therapeutic effects of CBP and PTX, thus show synergistic ability on cervical cancer.

RESULTS

FA-CBP/PTX-LPNs showed the sizes of 169.9 ± 5.6 nm, with a narrow size distribution of 0.151 ± 0.023. FA-CBP/PTX-LPNs exhibited pH-responsive drug release, high cellular uptake efficiency (66.7 ± 3.1%), and prominent cell inhibition capacity (23 ± 1.1%). In vivo tumor distribution and tumor inhibition efficiency of FA-CBP/PTX-LPNs was the highest, with no obvious body weight lost.

CONCLUSION

High tumor distribution and remarkable antitumor efficiency obtained using in vitro as well as in vivo models further proved the FA-CBP/PTX-LPNs is a promising tool for cervical cancer therapy.