Dual-targeting nanocarrier system based on thermosensitive liposomes and gold nanorods for cancer thermo-chemotherapy

Cellular Trojan Horse initiates bimetallic Fe-Cu MOF-mediated synergistic cuproptosis and ferroptosis against malignancies

Disruptions in metal balance can trigger a synergistic interplay of cuproptosis and ferroptosis, offering promising solutions to enduring challenges in oncology. Here, we have engineered a Cellular Trojan Horse, named MetaCell, which uses live neutrophils to stably internalize thermosensitive liposomal bimetallic Fe-Cu MOFs (Lip@Fe-Cu-MOFs). MetaCell can instigate cuproptosis and ferroptosis, thereby enhancing treatment efficacy. Mirroring the characteristics of neutrophils, MetaCell can evade the immune system and not only infiltrate tumors but also respond to inflammation by releasing therapeutic components, thereby surmounting traditional treatment barriers. Notably, Lip@Fe-Cu-MOFs demonstrate notable photothermal effects, inciting a targeted release of Fe-Cu-MOFs within cancer cells and amplifying the synergistic action of cuproptosis and ferroptosis. MetaCell has demonstrated promising treatment outcomes in tumor-bearing mice, effectively eliminating solid tumors and forestalling recurrence, leading to extended survival. This research provides great insights into the complex interplay between copper and iron homeostasis in malignancies, potentially paving the way for innovative approaches in cancer treatment.

Thermosensitive nanocomposite components for combined photothermal-photodynamic therapy in liver cancer treatment

Phototherapies, in the form of photodynamic therapy (PDT) and photothermal therapy (PTT), have great application prospects in the field of biomedical science due to high precision and non-invasiveness. Because of the limited therapeutic efficacy of single phototherapy, researchers start to focus on combined PTT-PDT. Here, we designed a composite nanomaterial for PTT-PDT. H-TiO₂ mesoporous spheres were prepared by sol-gel method and hydrogenation treatment. After modification with polydopamine (PDA), they were combined with indocyanine green (ICG) and NPe6 photosensitizers and coated by thermosensitive liposomes to prepare H-TiO₂ @PDA@ICG@NPe6 @Lipo nanocomposite component. The results indicated a substantial improvement of the component in the aspects of spectral response range, photothermal conversion efficiency and light absorption performance by modification and photosensitizers, in the absence of any toxicities on cells. Thermal induction and sequential irradiation with 808 nm and 664 nm lasers induced the aggregation of H-TiO₂ @PDA@ICG@NPe6 @Lipo at the tumor site to generate hyperthermia and massive reactive oxygen species (ROS), resulting in decreased cell activity or even cell apoptosis and restrained growth of allograft tumors. These findings underscore the favorable effects of H-TiO₂ @PDA@ICG@NPe6 @Lipo on the combined phototherapies and provide approaches for the development of nano-drugs in the context of liver cancer.

Thermosensitive liposomes: A promising step towards locsalised chemotherapy

INTRODUCTION

Many small molecules and biologic therapeutics have been developed for solid tumor therapy. However, the unique physiology of tumors makes the actual delivery of these drugs into the tumor mass inefficient. Such delivery requires transport from blood vessels, across the vasculature and into and through interstitial space within a tumor. This transportation is dependent on the physiochemical properties of the therapeutic agent and the biological properties of the tumour. It was hoped the application of nanoscale drug carrier systems would solve this problem. However, issues with poor tumor accumulation and limited drug release have impeded clinical impact. In response, these carrier systems have been redesigned to be paired with targetable external mechanical stimuli which can trigger much enhanced drug release and deposition.

AREAS COVERED

The pre-clinical and clinical progress of thermolabile drug carrier systems and the modalities used to trigger the release of their cargo, is assessed.

EXPERT OPINION

Combined application of mild hyperthermia and heat-responsive liposomal drug carriers has great potential utility. Clinical trials continue to progress this approach and serve to refine the technologies, dosing regimens and exposure parameters that will provide optimal patient benefit.

pH and Temperature Double-Switch Hybrid Micelles for Controllable Drug Release

pH/temperature dual-responsive hybrid micelles were prepared for constructing a double-locked drug delivery system. The temperature-sensitive polyethylene glycol-poly(tetrahydropyranylmethacrylate)-polyethylene glycol (PEG-PTHPMA-PEG) triblock copolymers were synthesized by reversible addition-fragmentation chain transfer polymerization and amide coupling reaction. pH-sensitive poly(2-(diisopropylamino ethylmethacrylate)-polyethylene glycol (PDPA-PEG) diblock polymers were introduced, which could self-assemble with PEG-PTHPMA-PEG in aqueous solutions to form hybrid micelles. The anticancer drug doxorubicin, which was encapsulated in the core of the hybrid micelles, could be released only under simultaneous stimulations of pH and temperature. It was proved that the micelles could maintain their structural stability under a unilateral stimulus, while the structure collapsed and recombined under a double stimulus, which triggered a large amount of drug release. Furthermore, the excellent biocompatibility and dual sensitivity of the vector were also proved by cytotoxicity experiments. The dual-responsive hybrid micelles designed here showed the advantages of a double insurance lock of drug leakage and precise controllability of drug release, which could act as accurate drug delivery systems.

Gold Nanorods: The Most Versatile Plasmonic Nanoparticles

Gold nanorods (NRs), pseudo-one-dimensional rod-shaped nanoparticles (NPs), have become one of the burgeoning materials in the recent years due to their anisotropic shape and adjustable plasmonic properties. With the continuous improvement in synthetic methods, a variety of materials have been attached around Au NRs to achieve unexpected or improved plasmonic properties and explore state-of-the-art technologies. In this review, we comprehensively summarize the latest progress on Au NRs, the most versatile anisotropic plasmonic NPs. We present a representative overview of the advances in the synthetic strategies and outline an extensive catalogue of Au-NR-based heterostructures with tailored architectures and special functionalities. The bottom-up assembly of Au NRs into preprogrammed metastructures is then discussed, as well as the design principles. We also provide a systematic elucidation of the different plasmonic properties associated with the Au-NR-based structures, followed by a discussion of the promising applications of Au NRs in various fields. We finally discuss the future research directions and challenges of Au NRs.

A Rapid Dual-Responsive Releasing Nano-Carrier by Decomposing the Copolymer and Reversing the Core Dissolution

The accumulation of nanotechnology-based drugs has been realized in various ways. However, the concentration of drugs encapsulated by nanomaterials is not equal to the concentration of effective drugs; often, the drugs become effective only when they are released from the nanomaterials as free drugs. This means only when the drugs are rapidly released after the accumulated drug-encapsulating nanomaterials can they truly achieve the purpose of increasing the concentration of drugs in the tumor. Therefore, we herein report a dual-response nano-carrier of glutathione and acid to achieve the rapid release of encapsulated drug and increase the effective drug concentration in the tumor. The nano-carrier was constructed using a dual-responsive amphiphilic copolymer, composed of polyethylene glycol and hydrophobic acetylated dextran and connected by a disulfide bond. In the tumor microenvironment, disulfide bonds could be biodegraded by glutathione that is overexpressed in the tumor, exposing the core of nano-carrier composed of acetylated dextran. Then the acidic environment would induce the deacetylation of acetylated dextran into water-soluble dextran. In this way, the nano-carrier will degrade quickly, realizing the purpose of rapid drug release. The results showed that the drug release rate of dual-responsive nano-carrier was much higher than that of glutathione or acid-responsive nano-carrier alone. Furthermore, both in vitro and in vivo experiments confirmed that dual-responsive nano-carrier possessed more efficient anti-tumor effects. Therefore, we believe that dual-responsive nano-carriers have better clinical application prospects.

Sonochemical preparation of folate-decorated reductive-responsive carboxymethylcellulose-based nanocapsules for targeted drug delivery

In this study, a biocompatible folate-decorated reductive-responsive carboxymethylcellulose-based nanocapsules (FA-RCNCs) were designed and prepared via sonochemical method for targeted delivery and controlled release of hydrophobic drugs. The shell of FA-RCNCs was cross-linked by disulfide bonds formed from hydrosulfuryl groups on the thiolated carboxymethylcellulose (TCMC) and encapsulated hydrophobic drug dispersed in the oil phase into nanocapsules. Moreover, the size and morphology of drug loaded FA-RCNCs were characterized by DLS, SEM and CLSM which indicated that the synthesized nanocapsules have suitable size range and excellent stability for circulating in the bloodstream. The drug release rate of FA-RCNCs could be controlled by adjusting their sizes and shell thickness, which could be dominated by the concentration of TCMC and sonochemical conditions. Furthermore, the obtained FA-RCNCs could be ingested into Hela cells via folate-receptor (FR)-mediated endocytosis and quickly release drugs under reductive environment, which demonstrated that FA-RCNCs could become potential hydrophobic drugs carries for cancer therapy.

Development of gold nanorods for cancer treatment

There has been growing interest in the application of gold nanorods (GNRs) to tumor therapy due to the unique properties they possess. In the past, GNRs were not used in clinical treatments as they lacked stability in vivo and were characterized by potential toxicity. Despite these issues, the significant potential for utilizing GNRs to conduct safe and effective treatments for tumors cannot be ignored. Therefore, it remains crucial to thoroughly investigate the mechanisms behind the toxicity of GNRs in order to provide the means of overcoming obstacles to its full application in the future. This review presents the toxic effects of GNRs, the factors affecting toxicity and the methods to improve biocompatibility, all of which are presently being studied. Finally, we conclude by briefly discussing the current research status of GNRs and provide additional perspective on the challenges involved along with the course of development for GNRs in the future.

pH-sensitive and bubble-generating mesoporous silica-based nanoparticles for enhanced tumor combination therapy

Chemotherapy has been a major option in clinic treatment of malignant tumors. However, single chemotherapy faces some drawbacks, such as multidrug resistance, severe side effects, which hinder its clinic application in tumor treatment. Multifunctional nanoparticles loading with chemotherapeutic agent and photosensitizer could be a promising way to efficiently conduct tumor combination therapy. In the current study, a novel pH-sensitive and bubble-generating mesoporous silica-based drug delivery system (denoted as M(a)D@PI-PEG-RGD) was constructed. Ammonium bicarbonate (NH₄HCO₃; abc) and chemotherapeutic agent doxorubicin (DOX) were loaded into the pores of mesoporous silica. Indocyanine green (ICG) as a photothermal and photodynamic agent was loaded onto the polydopamine (PDA) layer surface. The synthesized nanoparticles displayed a narrow polydispersity (PDI) and small particle size as characterized through dynamic light scattering-autosizer analysis. The nanoparticles also showed high targeting efficacy through RGD modification as indicated by cellular uptake and animal studies. DOX release analysis confirmed that the nanoparticles were pH-dependent and that NH₄HCO₃ accelerated drug release. At the same time, the nanoparticles had obvious photothermal and photodynamic effects performed by ICG which restrained tumor growth remarkably. In summary, the multifunctional nanoparticles presented a promising system for combination therapy.

Yolk-shell structured Au nanorods@mesoporous silica for gas bubble driven drug release upon near-infrared light irradiation

Drug release systems co-encapusulated with ammonium bicarbonate (ABC) could facilitate drug release upon acidic or thermal stimulations to improve therapeutic effect. However, it is not easy to control drug release rate, owing to relative stable temperature and acidic condition in living body. Besides, the additional loaded ABC reduces drug loading capacity. Herein, a near-infrared light triggered rapid drug release system with high loading capacity was developed by loading ABC and doxorubicin into yolk-shell structured Au nanorods@mesoporous silica. Gas bubbles were generated from the thermolysis of ABC utilizing photothermal effect of Au nanorods to extrude drug molecules. The mesoporous silica shell was finally destroyed along with growing bubbles, resulting in burst drug release. The photothermal therapeutic effect of Au nanorods also contributed in tumor treatment. The excellent therapeutic effect was demonstrated in cancer cells and tumor-bearing mice, which provides a new reference to achieve controllable rapid drug release in cancer medicine.

A nanosystem loaded with perfluorohexane and rose bengal coupled upconversion nanoparticles for multimodal imaging and synergetic chemo-photodynamic therapy of cancer

Theranostics is a new trend integrating diagnostic and therapeutic functions in tumour research. Theranostic nanoparticles enabling both tumour imaging and drug delivery are a promising platform for image-guided cancer therapy. Photodynamic therapy (PDT) has great potential in synergy with traditional chemotherapy but faces great challenges due to hypoxia, poor targeting ability and the limited penetration depth of visible light. To solve these problems, we presented a novel nanosystem of FA/UCNPs-RB/HCPT/PFH@lipid (denoted as FURH-PFH-NPs), with a perfluorohexane (PFH) carrying rich oxygen core and a folic acid-modified lipid shell. The shell contains 10-hydroxycamptothecin (HCPT) and self-fluorescing photosensitizer compounds, namely, upconversion nanoparticles and rose bengal (UCNPs-RB). In this study, FURH-PFH-NPs aggregated in SKOV3 cells (in vitro) and the nude xenograft tumour region when combined with folic acid receptors. When triggered by low-intensity focused ultrasound (LIFU), FURH-PFH-NPs released PFH, UCNPs-RB and HCPT. The above procedure was monitored through multimodal imaging, which simultaneously guided the tumour therapy. UCNPs-RB and PFH promoted the PDT effect under LIFU. Through PDT and HCPT, we obtained better therapeutic effects and good biosafety against SKOV3 nude xenograft tumours. FURH-PFH-NPs combined with LIFU and laser irradiation might be a promising strategy for ovarian cancer.

Past, Present, and Future of Anticancer Nanomedicine

This review aims to summarize the methods that have been used till today, highlight methods that are currently being developed, and predict the future roadmap for anticancer therapy. In the beginning of this review, established approaches for anticancer therapy, such as conventional chemotherapy, hormonal therapy, monoclonal antibodies, and tyrosine kinase inhibitors are summarized. To counteract the side effects of conventional chemotherapy and to increase limited anticancer efficacy, nanodrug- and stem cell-based therapies have been introduced. However, current level of understanding and strategies of nanodrug and stem cell-based therapies have limitations that make them inadequate for clinical application. Subsequently, this manuscript reviews methods with fewer side effects compared to those of the methods mentioned above which are currently being investigated and are already being applied in the clinic. The newer strategies that are already being clinically applied include cancer immunotherapy, especially T cell-mediated therapy and immune checkpoint inhibitors, and strategies that are gaining attention include the manipulation of the tumor microenvironment or the activation of dendritic cells. Tumor-associated macrophage repolarization is another potential strategy for cancer immunotherapy, a method which activates macrophages to immunologically attack malignant cells. At the end of this review, we discuss combination therapies, which are the future of cancer treatment. Nanoparticle-based anticancer immunotherapies seem to be effective, in that they effectively use nanodrugs to elicit a greater immune response. The combination of these therapies with others, such as photothermal or tumor vaccine therapy, can result in a greater anticancer effect. Thus, the future of anticancer therapy aims to increase the effectiveness of therapy using various therapies in a synergistic combination rather than individually.

Dual stimuli-responsive ursolic acid-embedded nanophytoliposome for targeted antitumor therapy

The hindrances in achieving clinically translatable anticancer platforms are being tackled through nanotechnology-based formulations. In this study, stimuli-responsive, phytoactive constituent-loaded nanophytoliposomes were fabricated for designing a specific antitumor platform. Ursolic acid (UA)-loaded nanophytoliposomes (UA-PLL-HA.P) enwrapped in a poly-L-lysine (PLL) coat and hyaluronic acid (HA) were nanosized; these nanophytoliposomes had spherical morphology, slightly negative charge, and an in-range polydispersity index (~0.25). Successful fabrication of the nanosystem was proven through several characterization methods and the pH- and enzyme-responsiveness of the nanosystem was assessed through a release study. The cellular internalization in CD44 receptor-expressing cell lines was amplified by enhanced permeation and retention as well as by active targeting. In vitro antitumor behavior was confirmed through in vitro cytotoxic and apoptotic activity of the nanosystem. Similarly, in vivo imaging showed exceptional biodistribution in the tumor in agreement with the in vitro findings. Moreover, the tumor inhibitory rate of UA-PLL-HA.P was significantly higher, and was ascribed to the targeting potential and stimuli-responsiveness. In summary, UA-PLL-HA.P exhibited pronounced anticancer effect and could open a number of possibilities for discovering novel phytoconstituent-incorporated nanoformulations.

Double security drug delivery system DDS constructed by multi-responsive (pH/redox/US) microgel

In this paper, the multi-responsive core-shell microgels were prepared for constructing a double-locked drug delivery system. The pH- sensitive poly(2-(diisopropylamino ethylmethacry-late)-block-poly(ethyleneimine) diblock copolymers (PDPA-b-PEI) were synthesized and used to prepare micelles through their self-assembly in neutral solution. Redox-responsive gel shells were formed by Michael addition of primary amine group of branched PEI using disulfide as a cross-linker, which was specifically cleaved by glutathione (GSH). Anticancer drug doxorubicin DOX and perfluorohexane (PFH) could be encapsulated in the core of microgel. The DOX was released sustainably only under the condition of pH and GSH were both right. For example, under neutral condition with GSH, DOX could not release swimmingly due to the core of microgels was in hydrophobic state and wrapped the DOX firmly, although the gel shells were collapsed by GSH. When exposed to ultrasound, the drug released abruptly and achieved a complete release instantly. Moreover, it was found that the structure of the microgels was not destroyed after the ultrasound stimulus but had undergone an expansion-recovery process. Finally, it was demonstrated that the microgel had a "double security" effect, ensuring the low drug leakage during the normal blood circulation and efficient drug release under the pH/redox/ultrasound stimulus. The multi-responsive microgels designed here, which combines the usage of both endogenous and exogenous stimuli, has the advantages of low side-effect, high spatiotemporal controllability and complete release.

Gold Nanoparticles in Glioma Theranostics

Despite many endeavors to treat malignant gliomas in the last decades, the median survival of patients has not significantly improved. The infiltrative nature of high-grade gliomas and the impermeability of the blood-brain barrier to the most therapeutic agents remain major hurdles, impeding an efficacious treatment. Theranostic platforms bridging diagnosis and therapeutic modalities aim to surmount the current limitations in diagnosis and therapy of glioma. Gold nanoparticles (AuNPs) due to their biocompatibility and tunable optical properties have widely been utilized for an assortment of theranostic purposes. In this Review, applications of AuNPs as imaging probes, drug/gene delivery systems, radiosensitizers, photothermal transducers, and multimodal theranostic agents in malignant gliomas are discussed. This Review also aims to provide a perspective on cancer theranostic applications of AuNPs in future clinical trials.

A multifunctional liposomal nanoplatform co-delivering hydrophobic and hydrophilic doxorubicin for complete eradication of xenografted tumors

In the war against cancer, tremendous efforts have been made by using a nanoparticle-based anticancer drug system. However, it is still a great challenge to achieve complete cure and eradication of cancer through chemotherapy. Here, we present a new multifunctional liposomal nanoplatform simultaneously loaded with hydrophilic doxorubicin hydrochloride in the aqueous core and hydrophobic debydrochlorination doxorubicin in the lipid bilayer. Compared with the traditional nanoparticle-based drug delivery system, this nanocarrier has three unique functions including a high payload of the same therapeutic agents with different water-solubilities, highly selective delivery of cargos to tumor cells and long-acting time with tumors. An excellent in vitro antitumor potency can be achieved with an IC50 of 0.91 μg mL-1 for this liposome, which is only half the IC50 of free doxorubicin. More importantly, extremely good antitumor efficacy in vivo is achieved since the mean tumor volume of all xenografted tumors is respectively ∼20% and ∼10% of that of the commercial liposomal doxorubicin formulation and the single doxorubicin liposomes on day 17 after being intravenously injected with the liposome nanoformulation 4 times. Moreover, the tumors were completely cured and eradicated on day 60 with no recurrence and the survival rate still remained at 70% after 365 days. Therefore, this multifunctional binary-drug loaded liposome provides a great potential platform for winning the war against cancer.

Didodecyldimethylammonium Bromide Role in Anchoring Gold Nanoparticles onto Liposome Surface for Triggering the Drug Release

Liposomes with their capacity to anchor gold nanoparticles (AuNPs) onto their surface are used in the treatment of several pathologies such as cancer. The objective of this work was the optimization of the vesicle composition by using cationic agents in order to reinforce the anchoring process of AuNPs, and for the study of the influence of local temperature and vesicle size on drug release. A Plackett-Burman design was conducted to determine the optimal composition for the anchoring of AuNPs. A comprehensive study of the influence of lipid bilayer composition on the surface charge, size, and polydispersity index (PdI) of liposomes was carried out. Afterwards, in vitro release studies by dialysis were performed and several release parameters were evaluated as a function of temperature. Cholesterol was fixed as the rigid agent and Didodecyldimethylammonium bromide (DDAB) was selected as the cationic lipid into the liposome bilayer. Photomicrographs revealed that DDAB facilitated the anchoring of AuNPs onto the liposomal surface. The anchoring of AuNPs also enhanced the amount and rate of calcein released, especially in extruded samples, at several incubating temperatures. In addition, it was observed that both the anchoring of AuNPs and the calcein release were improved by increasing the surface of the vesicles. The contributions of liposome composition (DDAB inclusion, incubation temperature, anchoring of AuNPs) and size and surface availability of the vesicles on calcein release could be used to design improved lipid nanostructures for the controlled release of anticancer drugs.

Current developments in drug delivery with thermosensitive liposomes

Thermosensitive liposomes (TSLs) have been an important research area in the field of tumor targeted chemotherapy. Since the first TSLs appeared that using 1,2-dipalmitoyl-sn-glyce-ro-3-phosphocholine (DPPC) as the primary liposomal lipid, many studies have been done using this type of liposome from basic and practical aspects. While TSLs composed of DPPC enhance the cargo release near the phase transition temperature, it has been shown that many factors affect their temperature sensitivity. Thus numerous attempts have been undertaken to develop new TSLs for improving their thermal response performance. The main objective of this review is to introduce the development and recent update of innovative TSLs formulations, including combination of radiofrequency ablation (RFA), high-intensity focused ultrasound (HIFU), magnetic resonance imaging (MRI) and alternating magnetic field (AMF). In addition, various factors affecting the design of TSLs, such as lipid composition, surfactant, size and serum components are also discussed.

A dual pH-sensitive liposomal system with charge-reversal and NO generation for overcoming multidrug resistance in cancer

In cancer therapy, chemotherapeutic drugs frequently encounter multidrug resistance (MDR) induced by the overexpression of drug transporters such as P-glycoprotein (P-gp). Herein, in order to overcome MDR and improve the effectiveness of chemotherapy, we developed a novel pH-sensitive charge-reversal and NO generation liposomal system by modifying a pH-sensitive polymer (PEG-PLL-DMA) on the surface of cationic liposomes for delivering a NO donor (DETA NONOate) and a chemotherapy drug (paclitaxel, PTX) into MDR cells. The proposed liposomal system (PTX/NO/DMA-L) exhibited a distinctive charge-reversal capacity, which was negatively charged under physiological conditions (pH 7.4) but could reverse to positive charge in a tumor microenvironment (pH 6.5) due to the cleavable amide linkages formed between PEG-PLL and DMA, leading to the improvement of cell uptake. Once arrived in the endosomes and lysosomes (pH 5.0), DETA NONOate was triggered to decompose and release NO, which further promoted the quick release of PTX and inhibited the P-gp mediated efflux. The charge-reversal, NO generation and NO-triggered rapid release of drugs could significantly increase the accumulation of PTX in tumors and eventually improve the antitumor efficacy. These results indicate that this dual pH-sensitive liposomal system is a highly promising approach for chemotherapy and may pave a new avenue for overcoming MDR in cancer.

Magnetic liposomes for light-sensitive drug delivery and combined photothermal–chemotherapy of tumors

The targeted delivery of anticancer drugs for improving the therapeutic efficacy and reducing the side effects has attracted great attention in cancer therapy.

Nitrogen-doped fluorescent carbon dots used for the imaging and tracing of different cancer cells

Here, we report the synthesis of nitrogen-doped fluorescent carbon (C) dots using a one-pot hydrothermal method.

Dual-functional melanin-based nanoliposomes for combined chemotherapy and photothermal therapy of pancreatic cancer

Pancreatic cancer, one of the most common gastrointestinal tract cancers, leads to a high mortality rate of over 80% among patients. Conventional chemotherapy with gemcitabine (GEM) is undesirable due to the lack of effective tumor accumulation. To improve the survival of pancreatic cancer patients and the therapeutic efficiency of chemotherapy, dual-functional melanin-based nanoliposomes loaded with GEM were synthesized in our study, which combined chemotherapy and photothermal therapy (PTT). Hypothermia caused by melanin under near-infrared (NIR) laser exerted detrimental damage on pancreatic cancer cells after the passive accumulation of nanoliposomes in the tumor sites. Besides, the temperature increase could enhance the release of GEM from the nanoliposomes by changing the structural integrity of the nanoliposomes. Therefore, a synergistic antitumor effect was achieved by loading the chemotherapy agent GEM and the photothermal agent melanin into the nanoliposomes. The findings in this study strongly support that melanin-based nanoliposomes could be a desirable strategy against pancreatic carcinoma.

GEM-Mel-Lip converted light to heat based on melanin after entering the tumor cells, and then the phospholipid fluidity was increased under the hyperthermia generated, resulting in the release of GEM.

Bubble-generating polymersomes loaded with both indocyanine green and doxorubicin for effective chemotherapy combined with photothermal therapy

The combination of chemotherapy and photothermaltherapy (PTT) via stimuli-responsive nanovesicles has great potential in tumor treatment. In the present study, bubble-generating polymersomes, which can generate bubbles in response to low pH or hyperthermia, were fabricated to simultaneously encapsulate chemotherapeutic drug and photosensitizing agent for the synergistic chemo-photothermal tumor therapy. Photosensitizer indocyanine green (ICG) was encapsulated into the bilayer of polymersomes formed by amphiphilic triblock copolymer PCL₈₀₀₀-PEG₈₀₀₀-PCL₈₀₀₀ through thin film re-hydration method, while chemotherapeutic doxorubicin (DOX) was loaded into the hydrophilic lumen using a transmembrane ammonium bicarbonate gradient loading procedure. Under acidic condition or laser irradiation, the ammonium bicarbonate (NH₄HCO₃) encapsulated in the bubble-generating DOX-ICG-co-delivery polymersomes (BG-DIPS) would decompose to produce CO₂ bubbles, resulting in destruction of vesicle structure and rapid drug release. In vitro drug release study confirmed that acidic environment and NIR laser irradiation could accelerate DOX release from the BG-DIPS. Cellular uptake study indicated that laser-induced hyperthermia highly enhanced endocytosis of BG-DIPS into 4T1-Luc cancer cells. In vitro cytotoxicity study demonstrated that BG-DIPS exhibited much higher cytotoxicity than free drugs under laser irradiation. In vivo biodistribution study indicated that BG-DIPS could accumulate in the tumor region, prolong drug retention, and increase photothermal conversion efficiency. Furthermore, in vivo antitumor study showed that BG-DIPS with laser irradiation efficiently inhibited 4T1-Luc tumor growth with reduced systemic toxicity. Hence, the formulated bubble-generating polymersomes system was a superior multifunctional nanocarrier for stimuli-response controlled drug delivery and combination chemo-photothermal tumor therapy.

STATEMENT OF SIGNIFICANCE

The combination of chemotherapy and photothermaltherapy via stimuli-responsive nanovesicles has great potential in tumor treatment. Herein, bubble-generating polymersomes, which can generate bubbles in response to low pH or hyperthermia, were fabricated to simultaneously encapsulate chemotherapeutic drug (DOX) and photosensitizing agent (ICG) for the synergistic chemo-photothermal tumor therapy. The results in vitro and in vivo demonstrated that bubble-generating DOX-ICG-co-delivery polymersomes (BG-DIPS) would accelerate DOX release from the BG-DIPS and accumulate in the tumor region, prolong drug retention, and increase photothermal conversion efficiency. BG-DIPS with laser irradiation could efficiently inhibited 4T1-Luc tumor growth with reduced systemic toxicity. Hence, the formulated bubble-generating polymersomes system was a superior multifunctional nanocarrier for stimuli-response controlled drug delivery and combination chemo-photothermal tumor therapy.

A dual-targeting reconstituted high density lipoprotein leveraging the synergy of sorafenib and antimiRNA21 for enhanced hepatocellular carcinoma therapy

Sorafenib (So) is a multi-target kinase inhibitor extensively used in clinic for hepatocellular carcinoma therapy. It demonstrated strong inhibition both in tumor proliferation and tumor angiogenesis, while hampered by associated cutaneous side-effect and drug resistance. The knockdown of miR-21 with antisense oligonucleotides (antimiRNA21) was regarded as an efficient strategy for increasing tumor sensibility to chemotherapy, which could be employed to appreciate the efficacy of So. Herein, we successfully formulated a dual-targeting delivery system for enhanced hepatocellular carcinoma therapy by encapsulating So and antimiRNA21 in RGD pentapeptide-modified reconstituted high-density lipoprotein (RGD-rHDL/So/antimiRNA21). The RGD and apolipoprotein A-I (ApoA-I) on nanoparticles (NPs) could drive the system simultaneously to tumor neovascular and parenchyma by binding to the overexpressed ανβ3-integrin and SR-B1 receptors, achieving precise delivery of therapeutics to maximize the efficacy. A series in vitro and in vivo experiments revealed that co-delivery of So and antimiRNA21 by RGD-rHDL significantly strengthened the anti-tumor and anti-angiogenic effect of So with negligible toxicity towards major organs, reversed drug-resistance and was capable of remodeling tumor environments. The constructed RGD-rHDL/So/antimiRNA21 with improved efficacy and excellent tumor targeting ability provided new idea for chemo-gene combined therapy in hepatocellular carcinoma.

STATEMENT OF SIGNIFICANCE

Sorafenib (So) is a multi-target kinase inhibitor which was approved by FDA as first-line drug for hepatocellular carcinoma (HCC) therapy. However, long term application of So in clinic was hampered by serious dermal toxicity and drug resistance. Although numerous researchers were devoted to finding alternatives or therapies as combination treatments with So to reach more desired therapeutic efficacy, the therapeutic options were still limited. The present study prepares RGD pentapeptide decorated biomimic reconstituted high-density lipoprotein (rHDL) loaded with So and antimiRNA21 (RGD-rHDL/So/antimiRNA21) for enhanced HCC therapy. The RGD-rHDL/So/antimiRNA21 NPs offer an effective platform for anti-tumor and anti-angiogenesis therapy in HCC and provide new approach to reverse drug-resistance of So for feasible clinical application.

NIR-Activated Polydopamine-Coated Carrier-Free "Nanobomb" for In Situ On-Demand Drug Release

Carrier-free nanoparticles with high drug loading have attracted increasing attention; however, in situ on-demand drug release remains a challenge. Here, a novel near-infrared (NIR) laser-induced blasting carrier-free nanodrug delivery system is designed and fabricated by coating doxorubicin (DOX) nanoparticles (DNPs) with a polydopamine film (PDA) that would prolong the blood circulation time of DNPs and avoid the preleakage of the DOX during blood circulation. Meanwhile, the NH4HCO3 is introduced to trigger in situ "bomb-like" release of DOX for the production of carbon dioxide (CO2) and ammonia (NH3) gases driven by NIR irradiated photothermal effect of PDA. Both in vitro and in vivo studies demonstrate that the carrier-free nanovectors with high drug loading efficiency (85.8%) prolong tumor accumulation, enhance chemotherapy, achieve the synergistic treatment of chemotherapy and photothermal treatment, and do not induce any foreign-body reaction over a three-week implantation. Hence, the delicate design opens a self-assembly path to develop PDA-based NIR-responsive multifunctional carrier-free nanoparticles for tumor therapy.

Ready-to-use protein G-conjugated gold nanorods for biosensing and biomedical applications

BACKGROUND

Gold nanorods (GNRs) display unique capacity to absorb and scatter near infrared light, which arises from their peculiar composition of surface plasmon resonances. For this reason, GNRs have become an innovative material of great hope in nanomedicine, in particular for imaging and therapy of cancer, as well as in photonic sensing of biological agents and toxic compounds for e.g. biomedical diagnostics, forensic analysis and environmental monitoring. As the use of GNRs is becoming more and more popular, in all these contexts, there is emerging a latent need for simple and versatile protocols for their modification with targeting units that may convey high specificity for any analyte of interest of an end-user.

RESULTS

We introduce protein G-coated GNRs as a versatile solution for the oriented immobilization of antibodies in a single step of mixing. We assess this strategy against more standard covalent binding of antibodies, in terms of biocompatibility and efficiency of molecular recognition in buffer, serum and plasma, in the context of the development of a direct immunoenzymatic assay. In both cases, we estimate an average of around 30 events of molecular recognition per particle. In addition, we disclose a convenient protocol to store these particles for months in a freezer, without any detrimental effect.

CONCLUSIONS

The biocompatibility and efficiency of molecular recognition is similar in either case of GNRs that are modified with antibodies by covalent binding or oriented immobilization through protein G. However, protein G-coated GNRs are most attractive for an end-user, owing to their unique versatility and ease of bioconjugation with antibodies of her/his choice.

Nanodiamonds facilitate killing of intracellular uropathogenic E. coli in an in vitro model of urinary tract infection pathogenesis

About 25–44% of women will experience at least one episode of recurrent UTI and the causative agent in over 70% of UTI cases is uropathogenic Escherichia coli (UPEC). UPEC cause recurrent UTI by evading the bladder’s innate immune system through internalization into the bladder epithelium where antibiotics cannot reach or be effective. Thus, it is important to develop novel therapeutics to eliminate these intracellular pathogens. Nanodiamonds (NDs) are biocompatible nanomaterials that serve as promising candidates for targeted therapeutic applications. The objective of the current study was to investigate if 6 or 25 nm NDs can kill extracellular and intracellular UPEC in infected bladder cells. We utilized the human bladder epithelial cell line, T24, and an invasive strain of UPEC that causes recurrent UTI. We found that acid-purified 6 nm NDs displayed greater antibacterial properties towards UPEC than 25 nm NDs (11.5% vs 94.2% CFU/mL at 100 μg/mL of 6 and 25 nm, respectively; P<0.001). Furthermore, 6 nm NDs were better than 25 nm NDs in reducing the number of UPEC internalized in T24 bladder cells (46.1% vs 81.1% CFU/mL at 100 μg/mL of 6 and 25 nm, respectively; P<0.01). Our studies demonstrate that 6 nm NDs interacted with T24 bladder cells in a dose-dependent manner and were internalized in 2 hours through an actin-dependent mechanism. Finally, internalization of NDs was required for reducing the number of intracellular UPEC in T24 bladder cells. These findings suggest that 6 nm NDs are promising candidates to treat recurrent UTIs.

Multifunctional gold nanorods and docetaxel-encapsulated liposomes for combined thermo- and chemotherapy

Personalized and precise nanomedicines are highly demanded for today’s medical needs. Liposomes are ideal candidates for the construction of multifunctional drug delivery systems. In this study, a liposome was used to improve the clinical issues of docetaxel (Doc), a potent antimitotic chemotherapy for prostate cancer (PC). RLT, a low-density lipoprotein receptor (LDLR)-binding peptide, and PEG were conjugated to the liposomes, and gold nanorods (GNRs) were also incorporated into the liposomes. The GNRs/Doc-liposome-RLT (GNRs/DocL-R) was tested in PC-3 cells and in PC-3 tumor-bearing nude mice. Results showed that GNRs/DocL-R possessed a diameter approximately 163.15±1.83 nm and a zeta potential approximately −32.8±2.16 mV. GNRs/DocL-R showed enhanced intracellular entrance, increased accumulation in the implanted tumor region, and the highest tumor inhibition in vitro and in vivo. Therefore, the multifunctional GNRs/DocL-R was a potential cancer treatment via combined chemo- and thermotherapy.

Mitochondria-targeting near-infrared light-triggered thermosensitive liposomes for localized photothermal and photodynamic ablation of tumors combined with chemotherapy

Lonidamine, an anticancer drug that acts on mitochondria, has poor water solubility. Mitochondria are the primary source of cellular reactive oxygen species (ROS), which are necessary for photodynamic therapy. Hence, a mitochondria-targeting drug delivery system loaded with Lonidamine and a ROS-produced photosensitizer could improve the bioavailability of Lonidamine and maximize photodynamic therapeutic efficiency. Here we report, for the first time, new IR-780 and Lonidamine encapsulated mitochondria-targeting thermosensitive liposomes (IL-TTSL). DSPE-PEG2000-NH₂ was coupled with triphenylphosphine to form DSPE-PEG_2K-TPP. The liposomes (IL-TTSL) were self-assembled from DPPC, DSPC, DSPE-PEG_2K-TPP, cholesterol, IR-780 and Lonidamine. Coupled linker modified triphenylphosphine (TPP) is cationic and can selectively accumulate several hundred-fold within mitochondria. Once the liposomes are located inside mitochondria, 808 nm laser irradiation could trigger photosensitizer IR-780 to elevate the local temperature, which could be utilized in photothermal therapy and induce the release of Lonidamine from the thermosensitive liposomes. Meanwhile, IR-780 could release ROS for photodynamic therapy in mitochondria and increase photodynamic therapeutic efficiency. Our results showed that the surface modification of the liposomes with triphenylphosphine cations had good mitochondria-targeting ability. The liposomes exhibited good biocompatibility and all components of the empty liposomes were safe to be used in humans. Few reports were related to IR-780 being used in photodynamic therapy and we proved this function of IR-780. Overall, the stealth liposomes provide a promising new strategy to realize mitochondria-targeting thermosensitive chemo-, photodynamic and photothermal combination therapy with a single light source for lung cancer.

NIR responsive liposomal system for rapid release of drugs in cancer therapy

To design a rapid release liposomal system for cancer therapy, a NIR responsive bubble-generating thermosensitive liposome (BTSL) system combined with photothermal agent (Cypate), doxorubicin (DOX), and NH4HCO3 was developed. Cypate/DOX-BTSL exhibited a good aqueous stability, photostability, and photothermal effect. In vitro release suggested that the amounts of DOX released from BTSL were obviously higher than that of (NH4)2SO4 liposomes at 42°C. After NIR irradiation, the hyperthermic temperature induced by Cypate led to the decomposition of NH4HCO3 and the generation of a large number of CO2 bubbles, triggering a rapid release of drugs. Confocal laser scanning microscope and acridine orange staining indicated that Cypate/DOX-BTSL upon irradiation could facilitate to disrupt the lysosomal membranes and realize endolysosomal escape into cytosol, improving the intracellular uptake of DOX clearly. MTT and trypan blue staining implied that the cell damage of Cypate/DOX-BTSL with NIR irradiation was more severe than that in the groups without irradiation. In vivo results indicated that Cypate/DOX-BTSL with irradiation could dramatically increase the accumulation of DOX in tumor, inhibit tumor growth, and reduce systemic side effects of DOX. These data demonstrated that Cypate/DOX-BTSL has the potential to be used as a NIR responsive liposomal system for a rapid release of drugs in thermochemotherapy.

Dual-targeted peptide-conjugated multifunctional fluorescent probe with AIEgen for efficient nucleus-specific imaging and long-term tracing of cancer cells

Precisely targeted transportation of a long-term tracing regent to a nucleus with low toxicity is one of the most challenging concerns in revealing cancer cell behaviors. Here, we report a dual-targeted peptide-conjugated multifunctional fluorescent probe (cNGR-CPP-NLS-RGD-PyTPE, TCNTP) with aggregation-induced emission (AIE) characteristic, for efficient nucleus-specific imaging and long-term and low-toxicity tracing of cancer cells. TCNTP mainly consists of two components: one is a functionalized combinatorial peptide (TCNT) containing two targeted peptides (cNGR and RGD), a cell-penetrating peptide (CPP) and a nuclear localization signal (NLS), which can specifically bind to a cell surface and effectively enter into the nucleus; the other one is an AIE-active tetraphenylethene derivative (PyTPE, a typical AIEgen) as fluorescence imaging reagent. In the presence of aminopeptidase N (CD13) and integrin αvβ3, TCNTP can specifically bind to both of them using cNGR and RGD, respectively, lighting up its yellow fluorescence. Because it contains CPP, TCNTP can be effectively integrated into the cytoplasm, and then be delivered into the nucleus with the help of NLS. TCNTP exhibited strong fluorescence in the nucleus of CD13 and integrin αvβ3 overexpression cells due to the specific targeting ability, efficient transport capacity and AIE characteristic in a more crowded space. Furthermore, TCNTP can be applied for long-term tracing in living cells, scarcely affecting normal cells with negligible toxicity in more than ten passages.

Nanomaterials engineering for drug delivery: a hybridization approach

The last twenty years have witnessed great advances in biology, medicine, and materials science, leading to the development of various nanoparticle (NP)-mediated drug delivery systems. Innovation in materials science has led the generation of biodegradable, biocompatible, stimuli-responsive, and targeted delivery systems. However, currently available nanotherapeutic technologies are not efficient, which has culminated in the failure of their clinical trials. Despite huge efforts devoted to drug delivery nanotherapeutics, only a small amount of the injected material could reach the desired target. One promising strategy to enhance the efficiency of NP drug delivery is to hybridize multiple materials, where each component could play a critical role in an efficient multipurpose delivery system. This review aims to comprehensively cover different techniques, materials, advantages, and drawbacks of various systems to develop hybrid nano-vesicles for drug delivery. Attention is finally given to the hybridization benefits in overcoming the biological barriers for drug delivery. It is believed that the advent of modern nano-formulations for multifunctional hybrid carriers paves the way for future advances to achieve more efficient drug delivery systems.

Gold nanoshell coated thermo-pH dual responsive liposomes for resveratrol delivery and chemo-photothermal synergistic cancer therapy

Stimuli-responsive drug delivery and release have a great significance in cancer therapy. Herein, a multifunctional responsive drug carrier was designed and developed by loading resveratrol (Res) in chitosan (CTS) modified liposomes, and coated by gold nanoshells (GNS@CTS@Res-lips). The resultant GNS@CTS@Res-lips possess broad near-infrared (NIR) absorbance, high capability, stability, and also high photothermal conversion ability for efficient photothermal therapy (PTT) applications. In addition, the GNS@CTS@Res-lips exhibit the on-demand pH/photothermal-sensitive drug release, and a high loading capacity of Res. Under NIR laser irradiation, the drug delivery system could significantly enhance the cellular uptake of drugs. More importantly, compared to the single chemotherapy or PTT, the carriers with NIR irradiation displayed a higher therapeutic effect for HeLa cells. Therefore, the GNS@CTS@Res-lips with a combination of chemotherapy and PTT will show great potential for application in cancer therapy.

Therapeutic Efficacy of Cisplatin Thermosensitive Liposomes upon Mild Hyperthermia in C26 Tumor Bearing BALB/c Mice

This study reports on the activity of thermosensitive liposomes (TSLs) incorporating different HSPC ratios in DPPC/MSPC/PEG₂₀₀₀-DSPE matrix (90/10/4) plus mild hyperthermia (HT) (42 °C). TSLs were loaded with a poorly membrane permeable anticancer drug, cisplatin, through the passive equilibration method. The addition of HSPC to the corresponding DPPC lipid matrix increased the transition temperature. In vitro data demonstrated >90% cisplatin leakage from nanosized DPPC 90-lyso-TSL (LTSL) within 10 min at 42 °C, while other TSLs bearing HSPC showed greater stability. The plasma kinetics of cisplatin demonstrated higher cisplatin leakage from DPPC 90-LTSL in the first 4 h (from 17.4 to 0.4 μg/mL) compared to other formulations. Indeed, increasing HSPC fraction in liposome bilayers significantly improved drug retention in blood. Though DPPC 90-LTSL plus one-step HT was expected to provide a unique drug release, the premature drug leakage as well as the likely wash-back of a great portion of drug into the blood circulation resulted in reduced survival. On the other hand, stabilized DPPC 30/HSPC 60/MSPC 10/PEG₂₀₀₀-DSPE 4 liposomes plus two-step HT greatly enhanced the survival of animals. In particular, the improved delivery of cisplatin through stabilized DPPC 30/HSPC 60/MSPC 10/PEG₂₀₀₀-DSPE 4 liposomes in two-step mild HT enhanced antitumor efficacy compared to other formulations. Thus, prolonged exposure of cancer cells to cisplatin through stabilized liposomes would be an efficient approach in improving the survival of animals.

Ursolic acid liposomes with chitosan modification: Promising antitumor drug delivery and efficacy

There are tremendous challenges on antitumor and its therapeutic drugs, and preparation of highly efficient nano-vehicles represents one of the novel topics in antitumor pharmaceutical field. Herein, the novel chitosan-coated ursolic acid (UA) liposome (CS-UA-L) was efficiently prepared with highly tumor targeting, drug controlled release and low side-effect. The CS-UA-L was uniformly spherical particles with diameter of ~130nm, and the size was more easily trapped into the tumor tissues. Chitosan modification can make liposomes carrying positive charges, which were inclined to combine with the negative charges on the surface of tumor cells, and then the CS-UA-L could release UA rapidly at pH5.0 comparing with pH7.4. Meanwhile, the CS-UA-L exhibited obvious anti-proliferative effect (76.46%) on HeLa cells and significantly antitumor activity (61.26%) in mice bearing U14 cervical cancer. The tumor tissues of CS-UA-L treated mice had enhanced cell apoptosis, extensive necrosis and low cell proliferation activity. These results demonstrated that the multifunctional CS-UA-L allowed a precision treatment for localized tumor, and reducing the total drug dose and side-effect, which hold a great promise in new safe and effective tumor therapy.