Recent trends in nano photo-chemo therapy approaches and future scopes

Hypoxia-Initiated Supramolecular Free Radicals Induce Intracellular Polymerization for Precision Tumor Therapy

Despite the development of various controlled release systems for antitumor therapies, off-target side effects remain a persistent challenge. In situ therapeutic synthesis from biocompatible substances offers a safer and more precise alternative. This study presents a hypoxia-initiated supramolecular free radical system capable of inducing intracellular polymerization, thereby disrupting the cytoskeleton and organelles within 4T1 cells. The system utilizes a 2:1 supramolecular host-guest complex of cucurbit[7]uril (CB[7]) and perylene diimide derivative (PDI), termed PDI+2CB[7], which is selectively reduced by the tumor's hypoxic and reducing environment to generate delocalized free radical anions. CB[7] effectively stabilizes these anions, enabling the PDI+2CB[7] complex to initiate free radical polymerization with 2-hydroxyethyl methacrylate (HEMA) inside the 4T1 cells. The resulting in situ polymerization significantly disrupts tumor metabolism, leading to a strong antitumor response without systemic toxicity. This study demonstrates that stable, endogenous stimulus-induced supramolecular free radicals can trigger intracellular polymerization reactions, achieving a selective and effective antitumor therapy without conventional chemotherapeutic agents.

Thermosensitive liposome-encapsulated gold nanocages for photothermal-modulated drug release and synergistic photothermal therapy

Delivery nanosystems have been widely developed to improve the efficacy of chemotherapy. However, their performance regarding the non-specific leakage of drugs remained unsatisfactory. Herein, gold nanocages (AuNCs) were used as carriers and thermo-sensitive liposome (TSL) as a protective shell to design a camptothecin (CPT)-loaded delivery nanosystem (AuNCs/CPT@TSL) for photothermal-modulated drug release. This approach effectively avoided the non-specific leakage of CPT and enabled the combination of photothermal therapy (PTT) and chemotherapy. In the simulated tumor microenvironment (pH = 5.5), the TSL shell prevented CPT leakage at 37 °C, with a release rate of only 11.4%. However, the release rate of CPT greatly increased to 85.4% when the temperature was elevated to 45 °C. The photothermal conversion efficiency of AuNCs/CPT@TSL reached up to 46.1%. At an incubation temperature of 37 °C, the cell survival rate decreased to 43.6% in AuNCs/CPT but remained above 90% in AuNCs/CPT@TSL, demonstrating the protective effect of the TSL shell. Under the combination of PTT and chemotherapy, cell viability drastically decreased to 10.9%, and the tumors completely disappeared, confirming the safe and reliable antitumor effect of AuNCs/CPT@TSL.

Emerging nitric oxide gas-assisted cancer photothermal treatment

Photothermal therapy (PTT) has garnered significant attention in recent years, but the standalone application of PTT still faces limitations that hinder its ability to achieve optimal therapeutic outcomes. Nitric oxide (NO), being one of the most extensively studied gaseous molecules, presents itself as a promising complementary candidate for PTT. In response, various nanosystems have been developed to enable the simultaneous utilization of PTT and NO-mediated gas therapy (GT), with the integration of photothermal agents (PTAs) and thermally-sensitive NO donors being the prevailing approach. This combination seeks to leverage the synergistic effects of PTT and GT while mitigating the potential risks associated with gas toxicity through the use of a single laser irradiation. Furthermore, additional internal or external stimuli have been employed to trigger NO release when combined with different types of PTAs, thereby further enhancing therapeutic efficacy. This comprehensive review aims to summarize recent advancements in NO gas-assisted cancer photothermal treatment. It commences by providing an overview of various types of NO donors and precursors, including those sensitive to photothermal, light, ultrasound, reactive oxygen species, and glutathione. These NO donors and precursors are discussed in the context of dual-modal PTT/GT. Subsequently, the incorporation of other treatment modalities such as chemotherapy (CHT), photodynamic therapy (PDT), alkyl radical therapy, radiation therapy, and immunotherapy (IT) in the creation of triple-modal therapeutic nanoplatforms is presented. The review further explores tetra-modal therapies, such as PTT/GT/CHT/PDT, PTT/GT/CHT/chemodynamic therapy (CDT), PTT/GT/PDT/IT, PTT/GT/starvation therapy (ST)/IT, PTT/GT/Ca2+ overload/IT, PTT/GT/ferroptosis (FT)/IT, and PTT/GT/CDT/IT. Finally, potential challenges and future perspectives concerning these novel paradigms are discussed. This comprehensive review is anticipated to serve as a valuable resource for future studies focused on the development of innovative photothermal/NO-based cancer nanotheranostics.

Amino acid-based metallo-supramolecular nanoassemblies capable of regulating cellular redox homeostasis for tumoricidal chemo-/photo-/catalytic combination therapy

Nanozymes, as nanomaterials with natural enzyme activities, have been widely applied to deliver various therapeutic agents to synergistically combat the progression of malignant tumors. However, currently common inorganic nanozyme-based drug delivery systems still face challenges such as suboptimal biosafety, inadequate stability, and inferior tumor selectivity. Herein, a super-stable amino acid-based metallo-supramolecular nanoassembly (FPIC NPs) with peroxidase (POD)- and glutathione oxidase (GSHOx)-like activities was fabricated via Pt4+-driven coordination co-assembly of l-cysteine derivatives, the chemotherapeutic drug curcumin (Cur), and the photosensitizer indocyanine green (ICG). The superior POD- and GSHOx-like activities could not only catalyze the decomposition of endogenous hydrogen peroxide into massive hydroxyl radicals, but also deplete the overproduced glutathione (GSH) in cancer cells to weaken intracellular antioxidant defenses. Meanwhile, FPIC NPs would undergo degradation in response to GSH to specifically release Cur, causing efficient mitochondrial damage. In addition, FPIC NPs intrinsically enable fluorescence/photoacoustic imaging to visualize tumor accumulation of encapsulated ICG in real time, thereby determining an appropriate treatment time point for tumoricidal photothermal (PTT)/photodynamic therapy (PDT). In vitro and in vivo findings demonstrated the quadruple orchestration of catalytic therapy, chemotherapeutics, PTT, and PDT offers conspicuous antineoplastic effects with minimal side reactions. This work may provide novel ideas for designing supramolecular nanoassemblies with multiple enzymatic activities and therapeutic functions, allowing for wider applications of nanozymes and nanoassemblies in biomedicine.

Chlorin e6-Conjugated Mesoporous Titania Nanorods as Potential Nanoplatform for Photo-Chemotherapy

Photodynamic therapy (PDT) has developed as an efficient strategy for cancer treatment. PDT involves the production of reactive oxygen species (ROS) by light irradiation after activating a photosensitizer (PS) in the presence of O2. PS-coupled nanomaterials offer additional advantages, as they can merge the effects of PDT with conventional enabling-combined photo-chemotherapeutics effects. In this work, mesoporous titania nanorods were surface-immobilized with Chlorin e6 (Ce6) conjugated through 3-(aminopropyl)-trimethoxysilane as a coupling agent. The mesoporous nanorods act as nano vehicles for doxorubicin delivery, and the Ce6 provides a visible light-responsive production of ROS to induce PDT. The nanomaterials were characterized by XRD, DRS, FTIR, TGA, N2 adsorption-desorption isotherms at 77 K, and TEM. The obtained materials were tested for their singlet oxygen and hydroxyl radical generation capacity using fluorescence assays. In vitro cell viability experiments with HeLa cells showed that the prepared materials are not cytotoxic in the dark, and that they exhibit photodynamic activity when irradiated with LED light (150 W m-2). Drug-loading experiments with doxorubicin (DOX) as a model chemotherapeutic drug showed that the nanostructures efficiently encapsulated DOX. The DOX-nanomaterial formulations show chemo-cytotoxic effects on Hela cells. Combined photo-chemotoxicity experiments show enhanced effects on HeLa cell viability, indicating that the conjugated nanorods are promising for use in combined therapy driven by LED light irradiation.

Nanocarrier-Integrated Microneedles: Divulging the Potential of Novel Frontiers for Fostering the Management of Skin Ailments

The various kinds of nanocarriers (NCs) have been explored for the delivery of therapeutics designed for the management of skin manifestations. The NCs are considered as one of the promising approaches for the skin delivery of therapeutics attributable to sustained release and enhanced skin penetration. Despite the extensive applications of the NCs, the challenges in their delivery via skin barrier (majorly stratum corneum) have persisted. To overcome all the challenges associated with the delivery of NCs, the microneedle (MN) technology has emerged as a beacon of hope. Programmable drug release, being painless, and its minimally invasive nature make it an intriguing strategy to circumvent the multiple challenges associated with the various drug delivery systems. The integration of positive traits of NCs and MNs boosts therapeutic effectiveness by evading stratum corneum, facilitating the delivery of NCs through the skin and enhancing their targeted delivery. This review discusses the barrier function of skin, the importance of MNs, the types of MNs, and the superiority of NC-loaded MNs. We highlighted the applications of NC-integrated MNs for the management of various skin ailments, combinational drug delivery, active targeting, in vivo imaging, and as theranostics. The clinical trials, patent portfolio, and marketed products of drug/NC-integrated MNs are covered. Finally, regulatory hurdles toward benchtop-to-bedside translation, along with promising prospects needed to scale up NC-integrated MN technology, have been deliberated. The current review is anticipated to deliver thoughtful visions to researchers, clinicians, and formulation scientists for the successful development of the MN-technology-based product by carefully optimizing all the formulation variables.

High Drug-Loading Nanomedicines for Tumor Chemo-Photo Combination Therapy: Advances and Perspectives

The combination of phototherapy and chemotherapy (chemo−photo combination therapy) is an excellent attempt for tumor treatment. The key requirement of this technology is the high drug-loading nanomedicines, which can load either chemotherapy drugs or phototherapy agents at the same nanomedicines and simultaneously deliver them to tumors, and play a multimode therapeutic role for tumor treatment. These nanomedicines have high drug-loading efficiency (>30%) and good tumor combination therapeutic effect with important clinical application potential. Although there are many reports of high drug-loading nanomedicines for tumor therapy at present, systematic analyses on those nanomedicines remain lacking and a comprehensive review is urgently needed. In this review, we systematically analyze the current status of developed high drug-loading nanomedicines for tumor chemo−photo combination therapy and summarize their types, methods, drug-loading properties, in vitro and in vivo applications. The shortcomings of the existing high drug-loading nanomedicines for tumor chemo−photo combination therapy and the possible prospective development direction are also discussed. We hope to attract more attention for researchers in different academic fields, provide new insights into the research of tumor therapy and drug delivery system and develop these nanomedicines as the useful tool for tumor chemo−photo combination therapy in the future.

The emergence of nanoporous materials in lung cancer therapy

Lung cancer is one of the most common cancers, affecting more than 2.1 million people across the globe every year. A very high occurrence and mortality rate of lung cancer have prompted active research in this area with both conventional and novel forms of therapies including the use of nanomaterials based drug delivery agents. Specifically, the unique physico-chemical and biological properties of porous nanomaterials have gained significant momentum as drug delivery agents for delivering a combination of drugs or merging diagnosis with targeted therapy for cancer treatment. This review focuses on the emergence of nano-porous materials for drug delivery in lung cancer. The review analyses the currently used nanoporous materials, including inorganic, organic and hybrid porous materials for delivering drugs for various types of therapies, including chemo, radio and phototherapy. It also analyses the selected research on stimuli-responsive nanoporous materials for drug delivery in lung cancer before summarizing the various findings and projecting the future of emerging trends. This review provides a strong foundation for the current status of the research on nanoporous materials, their limitations and the potential for improving their design to overcome the unique challenges of delivering drugs for the treatment of lung cancer.

Photo-Enhanced Chemotherapy Performance in Bladder Cancer Treatment via Albumin Coated AIE Aggregates

The implementation of cisplatin-based neoadjuvant chemotherapy (NAC) plays a key role in conjunction with surgical resection in preventing bladder cancer progression and recurrence. However, the significant dose-dependent toxic side effects of NAC are still a major challenge. To solve this problem, we developed a photoenhanced cancer chemotherapy (PECC) strategy based on AIEgen ((E)-3-(2-(2-(5-(4-(diphenylamino)phenyl)thiophen-2-yl)vinyl)-1,1-dimethyl-1H-3λ⁴-benzo[e]indol-3-yl)propane-1-sulfonate), which is abbreviated as BITT. Multifunctional BITT@BSA-DSP nanoparticles (NPs) were employed with an albumin-based nanocarrier decorated with the cisplatin(IV) prodrug and loaded to produce strong near-infrared fluorescence imaging (NIR FLI), and they exhibited good photoenhancement performance via photodynamic therapy (PDT) and photothermal therapy (PTT). In vitro results demonstrated that BITT@BSA-DSP NPs could be efficiently taken up by bladder cancer cells and reduced to release Pt (II) under reductase, ensuring the chemotherapy effect. Furthermore, both in vitro and in vivo evaluation verified that the integration of NIR FL imaging-guided PECC efficiently promoted the sensitivity of bladder cancer to cisplatin chemotherapy with negligible side effects. This work provides a promising strategy to enhance the sensitivity of multiple cancers to chemotherapy drugs and even achieve effective treatments for drug-resistant cancers.

Artesunate Drug-loaded 2D Nano-shuttle Landing on RBCs Infected with Malaria Parasites

Artesunic acid (AS0), a derivative of artemisinin, is recommended for the treatment of severe and complicated malaria, but its use is limited because of limitations such as short half-life, non-specific...

Using mathematical modeling to estimate time-independent cancer chemotherapy efficacy parameters

One of the primary cancer treatment modalities is chemotherapy. Unfortunately, traditional anti-cancer drugs are often not selective and cause damage to healthy cells, leading to serious side effects for patients. For this reason more targeted therapeutics and drug delivery methods are being developed. The effectiveness of new treatments is initially determined via in vitro cell viability assays, which determine the IC 50  of the drug. However, these assays are known to result in estimates of IC 50  that depend on the measurement time, possibly resulting in over- or under-estimation of the IC 50 . Here, we test the possibility of using cell growth curves and fitting of mathematical models to determine the IC 50  as well as the maximum efficacy of a drug ( ε max ). We measured cell growth of MCF-7 and HeLa cells in the presence of different concentrations of doxorubicin and fit the data with a logistic growth model that incorporates the effect of the drug. This method leads to measurement time-independent estimates of IC 50  and ε max , but we find that ε max  is not identifiable. Further refinement of this methodology is needed to produce uniquely identifiable parameter estimates.

Multifunctional CuxS- and DOX-loaded AuNR@mSiO2 platform for combined melanoma therapy with inspired antitumor immunity

Combined antitumor therapies based on nanomedicines have shown efficacy in various tumor models in recent years, overcoming the disadvantages of inefficiency and undesired toxicity of traditional therapies. Herein, we present a copper sulfide- and doxorubicin-loaded gold nanorods@mesoporous SiO2 multifunctional nanocomposite (AuNR@mSiO2@DOX-CuxS-PEG) to integrate chemotherapy, the photothermal properties of AuNRs, and the photodynamic properties of CuxS into a single nanoplatform based on hydrophobic interaction and electrostatic attraction. Upon near-infrared light irradiation, the AuNR@mSiO2@DOX-CuxS-PEG nanocomposites exhibit a synergistic therapeutic effect and inhibit the in situ tumor growth and lung metastasis in a melanoma model. This occurs because of the high photothermal conversion efficiency, boosted intracellular reactive oxygen species production, and excellent doxorubicin (DOX) release, as well as an induced tumor-specific immune response. The inspired antitumor immunity was confirmed by elevated infiltration of activated T cells in tumor tissues and improved maturation and activation of dendritic cells in tumor-draining lymph nodes. This study highlights the superior antitumor therapeutic effect elicited by a multifunctional nanoplatform for skin with in situ melanoma and lung metastasis inhibition, indicating its satisfactory clinical application prospects.

Cellulose nanocrystals in cancer diagnostics and treatment

Cancer is currently a major threat to public health, being among the principal causes of death to the global population. With carcinogenesis mechanisms, cancer invasion, and metastasis remaining blurred, cancer diagnosis and novel drug delivery approaches should be developed urgently to enable management and treatment. A dream break-through would be a non-invasive instantaneous monitoring of cancer initiation and progression to fast-track diagnosis for timely specialist treatment decisions. These innovations would enhance the established treatment protocols, unlimited by evasive biological complexities during tumorigenesis. It is therefore contingent that emerging and future scientific technologies be equally biased towards such innovations by exploiting the apparent properties of new developments and materials especially nanomaterials. CNCs as nanomaterials have undisputable physical and excellent biological properties that enhanced their interest as biomedical materials. This article therefore highlights CNCs utility in cancer diagnosis and therapy. Their extraction, properties, modification, in-vivo/in-vitro medical applications, biocompatibility, challenges and future perspectives are precisely discussed.

A Near-Infrared Laser-Triggered Size-Shrinkable Nanosystem with In Situ Drug Release for Deep Tumor Penetration

The development of smart size-tunable drug delivery nanoplatform enables the solving of the paradox of inconsistent size-dependence of high tumor accumulation and deep penetration during its delivery process, thus achieving superior cancer treatment efficacy. Herein, we report a size-shrinkable nanomicelle complex system with an initial size of 101 nm enabling effective retention around the tumor periphery and could destruct to ultrasmall nanomicelles triggered by a near-infrared (NIR) laser to realize the deep tumor penetration. The nanomicelle system is consisted of an upper critical solution temperature (UCST)-type block copolymer poly(acrylamide-acrylonitrile)-polyethylene glycol-lipoic acid (p(AAm-co-AN)-g-PEG-LA) encapsulating gold nanorods. Upon the irradiation of the NIR laser at the tumor site, gold nanorods could convert the light energy to heat energy, realizing the photothermal ablation of superficial tumor tissue. Concurrently, the large micelles split into a cascade of ultrasmall micelles (∼7 nm), which could easily penetrate into the deep site of the tumor and achieve the in situ "on-demand" release of the loaded drug to exert superior combined photothermal-chemotherapy of cancer. By the precise manipulation of laser, the micelle complex system realized the hierarchical killing from the superficial-to-deep tumor and achieved almost complete tumor growth inhibition on the established xenograft liver tumor mice model.

Recent Developments on Semiconducting Polymer Nanoparticles as Smart Photo-Therapeutic Agents for Cancer Treatments-A Review

Semiconducting polymer nanoparticles (SPN) have been emerging as novel functional nano materials for phototherapy which includes PTT (photo-thermal therapy), PDT (photodynamic therapy), and their combination. Therefore, it is important to look into their recent developments and further explorations specifically in cancer treatment. Therefore, the present review describes novel semiconducting polymers at the nanoscale, along with their applications and limitations with a specific emphasis on future perspectives. Special focus is given on emerging and trending semiconducting polymeric nanoparticles in this review based on the research findings that have been published mostly within the last five years.

Smart transformable nanomedicines for cancer therapy

Despite that great progression has been made in nanoparticulate drug delivery systems (nano-DDS), multiple drug delivery dilemmas still impair the delivery efficiency of nanomedicines. Rational design of smart transformable nano-DDS based on the in vivo drug delivery process represents a promising strategy for overcoming delivery obstacle of nano-DDS. In recent years, tremendous efforts have been devoted to developing smart transformable anticancer nanomedicines. Herein, we provide a review to outline the advances in this emerging field. First, smart size-reducible nanoparticles (NPs) for deep tumor penetration are summarized, including carrier degradation-induced, protonation-triggered and photobleaching-induced size reduction. Second, emerging transformable nanostructures for various therapeutic applications are discussed, including prolonging tumor retention, reversing drug-resistance, inhibiting tumor metastasis, preventing tumor recurrence and non-pharmaceutical therapy. Third, shell-detachable nanocarriers are introduced, focusing on chemical bonds breaking-initiated, charge repulsion-mediated and exogenous stimuli-triggered shell detachment approaches. Finally, the future perspectives and challenges of transformable nanomedicines in clinical cancer therapy are highlighted.

Using copper sulfide nanoparticles as cross-linkers of tumor microenvironment responsive polymer micelles for cancer synergistic photo-chemotherapy

Photo-chemotherapy presents promising therapeutic effects in cancer treatment. Photo-thermal and chemotherapeutic agents are generally delivered independently or jointly by drug carriers, such as polymer micelles. A polymer micelle is one type of widely researched drug carrier. However, there is a disassembly risk for polymer micelles under excessive dilution in blood circulation, leading to the premature release of payloads from the micelles and finally resulting in undesirable toxic side effects. Herein, amino-PEG decorated copper sulfide nanoparticles (CuS NPs) with photothermal effect were applied as a cross-linker to enhance polymeric micelles' stability and to provide photothermal therapy in the meanwhile. The micelles were prepared using a pH/reductive responsive polymer, poly(ε-caprolactone)-ss-poly(2-(diisopropylamino)ethyl methacrylate/glycidyl methacrylate/2-methylacrylloxyethyl phosphorylcholine (PCL-SS-P(DPA/GMA/MP)), abbreviated as DGM. Cross-linked micelles (DGM-CuS) exhibited high photothermal transformation efficiency and excellent stability against dilution, as well as pH and redox responsive drug release. Under near-infrared laser irradiation, the cell cytotoxicity of doxorubicin-loaded micelles DGM-CuS@DOX and DGM-CuS@DOX-P (DGM-CuS@DOX modified by peptides) increased by 17.1 times and 69.2 times correspondingly compared to that without laser irradiation. All of the solid 4T1 tumors disappeared, and tumor metastases were merely observed in the major organs of the tumor-bearing mice after administration of DGM-CuS@DOX and DGM-CuS@DOX-P with irradiation. In this synergistic therapy system, CuS NPs play double roles of a photothermal agent and a micelle cross-linker. The strategy of utilizing nanoparticles as cross-linkers is newly reported, which offers new insight for combination therapy.

Recent progress in layered double hydroxides as a cancer theranostic nanoplatform

Layered double hydroxide (LDH) has been a big challenge in exploring new hybrid materials by intercalating inorganic, organic, or bio molecules into their lamellar lattice, those which often showed dual functions from each other or new mutative properties. Recently, nano-bio convergence technology becomes one of the most extensively studied research fields in the view point of developing advanced drugs and diagnostic agents to fight against disease and eventually to improve the lives of human beings. Therefore, LDH as one of the nanomaterials have been intensively investigated not only as biocompatible drug delivery vehicle for cancer chemotherapy but also as diagnostic and imaging agents. In the present review, we have attempted to summarize theranostic functions of drug-LDH hybrid nanoparticles including their synthetic methods, physico-chemical and biological properties, and their unique mechanism overcoming drug resistance, and targeting properties based on in vitro and finally in vivo results. This article is categorized under: Diagnostic Tools > Diagnostic Nanodevices Diagnostic Tools > in vivo Nanodiagnostics and Imaging.

Recent Advances in Nanomaterial-Assisted Combinational Sonodynamic Cancer Therapy

Ultrasound (US)-triggered sonodynamic therapy (SDT), as a promising noninvasive therapeutic modality, has received ever-increasing attention in recent years. Its specialized chemical agents, named sonosensitizers, are activated by low-intensity US to produce lethal reactive oxygen species (ROS) for oncotherapy. Compared with phototherapeutic strategies, SDT provides many noteworthy opportunities and benefits, such as deeper penetration depth, absence of phototoxicity, and fewer side effects. Nevertheless, previous studies have also demonstrated its intrinsic limitations. Thanks to the facile engineering nature of nanotechnology, numerous novel nanoplatforms are being applied in this emerging field to tackle these intrinsic barriers and achieve continuous innovations. In particular, the combination of SDT with other treatment strategies has demonstrated a superior efficacy in improving anticancer activity relative to that of monotherapies alone. Therefore, it is necessary to summarize the nanomaterial-assisted combinational sonodynamic cancer therapy applications. Herein, the design principles in achieving synergistic therapeutic effects based on nanomaterial engineering methods are highlighted. The ultimate goals are to stimulate the design of better-quality combined sonodynamic treatment schemes and provide innovative ideas for the perspectives of SDT in promoting its future transformation to clinical application.

Learning from Nature: Bioinspired Chlorin-Based Photosensitizers Immobilized on Carbon Materials for Combined Photodynamic and Photothermal Therapy

Chlorophylls, which are chlorin-type photosensitizers, are known as the key building blocks of nature and are fundamental for solar energy metabolism during the photosynthesis process. In this regard, the utilization of bioinspired chlorin analogs as photosensitizers for photodynamic therapy constitutes an evolutionary topic of research. Moreover, carbon nanomaterials have been widely applied in photodynamic therapy protocols due to their optical characteristics, good biocompatibility, and tunable systematic toxicity. Herein, we review the literature related to the applications of chlorin-based photosensitizers that were functionalized onto carbon nanomaterials for photodynamic and photothermal therapies against cancer. Rather than a comprehensive review, we intended to highlight the most important and illustrative examples over the last 10 years.

Water-soluble cyclometalated Ir(III) complexes as carrier-free and pure nanoparticle photosensitizers for photodynamic therapy and cell imaging

Herein, we provide a new and facile strategy to successfully overcome the inherent aggregation-caused quenching effect and hydrophobicity that exist in traditional PSs by the introduction of sodium salts. The obtained water-soluble Ir(iii) complexes as carrier-free and pure nanoparticle photosensitizers exhibit excellent performance in photodynamic therapy and cell imaging.

Polythiophenes with Cationic Phosphonium Groups as Vectors for Imaging, siRNA Delivery, and Photodynamic Therapy

In this work, we exploit the versatile function of cationic phosphonium-conjugated polythiophenes to develop multifunctional platforms for imaging and combined therapy (siRNA delivery and photodynamic therapy). The photophysical properties (absorption, emission and light-induced generation of singlet oxygen) of these cationic polythiophenes were found to be sensitive to molecular weight. Upon light irradiation, low molecular weight cationic polythiophenes were able to light-sensitize surrounding oxygen into reactive oxygen species (ROS) while the highest were not due to its aggregation in aqueous media. These polymers are also fluorescent, allowing one to visualize their intracellular location through confocal microscopy. The most promising polymers were then used as vectors for siRNA delivery. Due to their cationic and amphipathic features, these polymers were found to effectively self-assemble with siRNA targeting the luciferase gene and deliver it in MDA-MB-231 cancer cells expressing luciferase, leading to 30-50% of the gene-silencing effect. In parallel, the photodynamic therapy (PDT) activity of these cationic polymers was restored after siRNA delivery, demonstrating their potential for combined PDT and gene therapy.