Trackable Mitochondria-Targeting Nanomicellar Loaded with Doxorubicin for Overcoming Drug Resistance

Dual Receptor-Targeted and Redox-Sensitive Polymeric Micelles Self-Assembled from a Folic Acid-Hyaluronic Acid-SS-Vitamin E Succinate Polymer for Precise Cancer Therapy

Purpose

Poor site-specific delivery and insufficient intracellular drug release in tumors are inherent disadvantages to successful chemotherapy. In this study, an extraordinary polymeric micelle nanoplatform was designed for the efficient delivery of paclitaxel (PTX) by combining dual receptor-mediated active targeting and stimuli response to intracellular reduction potential.

Methods

The dual-targeted redox-sensitive polymer, folic acid-hyaluronic acid-SS-vitamin E succinate (FHSV), was synthesized via an amidation reaction and characterized by ¹H-NMR. Then, PTX-loaded FHSV micelles (PTX/FHSV) were prepared by a dialysis method. The physiochemical properties of the micelles were explored. Moreover, in vitro cytological experiments and in vivo animal studies were carried out to evaluate the antitumor efficacy of polymeric micelles.

Results

The PTX/FHSV micelles exhibited a uniform, near-spherical morphology (148.8 ± 1.4 nm) and a high drug loading capacity (11.28% ± 0.25). Triggered by the high concentration of glutathione, PTX/FHSV micelles could quickly release their loaded drug into the release medium. The in vitro cytological evaluations showed that, compared with Taxol or single receptor-targeted micelles, FHSV micelles yielded higher cellular uptake by the dual receptor-mediated endocytosis pathway, thus leading to significantly superior cytotoxicity and apoptosis in tumor cells but less cytotoxicity in normal cells. More importantly, in the in vivo antitumor experiments, PTX/FHSV micelles exhibited enhanced tumor accumulation and produced remarkable tumor growth inhibition with minimal systemic toxicity.

Conclusion

Our results suggest that this well-designed FHSV polymer has promising potential for use as a vehicle of chemotherapeutic drugs for precise cancer therapy.

Dual-responsive TPGS crosslinked nanocarriers to overcome multidrug resistance

Efficient delivery of chemotherapeutic agents into tumor cells and reversal of chemoresistance are crucially important to enhance cancer therapy.

Fluorine-containing graphene quantum dots with a high singlet oxygen generation applied for photodynamic therapy

Compared with graphene quantum dots (GQDs), fluorine-containing GQDs (F-GQDs) present higher ¹O₂ generation under light irradiation and thus cause obvious toxicity to HepG2 cells. F-GQDs can be used as a photosensitizer for photodynamic therapy.

Aptamer-Based Erythrocyte-Derived Mimic Vesicles Loaded with siRNA and Doxorubicin for the Targeted Treatment of Multidrug-Resistant Tumors

Multidrug resistance (MDR) remains one of the most important challenges to clinical chemotherapeutics. In this study, versatile mimic vesicles (MVs) derived from erythrocytes were investigated as delivery systems for siRNA and doxorubicin (DOX) to treat MDR tumors. The carriers could be readily obtained through extruding erythrocyte membranes and had the advantages of biological homogeneity, high output, controllable size, low cost, and excellent biocompatibility. Moreover, aptamers modified on the MVs endowed the carriers with tumor-targeting capacity. DOX and P-glycoprotein (P-gp) siRNA were loaded onto the MVs through incubation and cholesterol-mediated methods, achieving high loading rates and targeted tumor delivery. The drug-loaded carriers could successfully overcome drug resistance and synergistically kill MDR tumors through P-gp silencing and DOX-induced growth inhibition. This MV-based drug delivery system therefore provides new insights into the synergistic targeting of MDR tumors and offers an alternative delivery strategy to overcome MDR.

Retrosynthesis of Tunable Fluorescent Carbon Dots for Precise Long-Term Mitochondrial Tracking

Mitochondria play a significant role in many cellular processes. Precise long-term tracking of mitochondrial status and behavior is very important for regulating cell fate and treating mitochondrial diseases. However, developing probes with photostability, long-term tracking capability, and tunable long-wavelength fluorescence has been a challenge in mitochondrial targeting. Carbon dots (CDs) as new fluorescent nanomaterials with low toxicity and high stability show increasing advantages in bioimaging. Herein, the mitochondria tracking CDs (MitoTCD) with intrinsic mitochondrial imaging capability and tunable long-wavelength fluorescence from green to red are synthesized where the lipophilic cation of rhodamine is served as the luminescent center of CDs. Due to the excellent photostability, superior fluorescence properties and favorable biocompatibility, these MitoTCD are successfully used for mitochondrial targeting imaging of HeLa cells in vitro and can be tracked as long as six passages, which is suitable for long-term cell imaging. Moreover, these MitoTCD can also be used for zebrafish imaging in vivo.

A multi-functionalized nanocomposite constructed by gold nanorod core with triple-layer coating to combat multidrug resistant colorectal cancer

Multi-drug resistance (MDR) remains the main culprit for the low survival rate of advanced colorectal cancer (CRC). Photothermal-therapy (PPT) is effective to kill MDR tumor cells, but fails to completely eradicate tumors. In this study, we prepared a nanocomposite based on gold nanorod core with triple layer coating (GNRs/mSiO₂/PHIS/TPGS/DOX) to combat multidrug resistant (MDR) colorectal cancer via multi-strategies. We first synthesized the mesoporous silica-coated gold nanorods (GNRs/mSiO₂), and loaded with antitumor drug doxorubicin (DOX) to realize a combination of chemo- and photothermal-therapy. To reverse DOX resistance, pH responsive poly-histidine (PHIS) was conjugated on GNRs/mSiO₂ to increase drug intracellular accumulation via efficient endo/lysosome escape; d-α-tocopherol polyethylene glycol 1000 succinate (TPGS) was then assembled on the surface of the particles to realize drug intracellular retention by inhibition P-glycoprotein. The results showed that the nanocomposite exhibited a highly efficient photothermal conversion in the NIR region, a pH and NIR triggered drug release profile and an increment of DOX intracellular accumulation and cytotoxicity on MDR SW620/Ad300 cells. Most importantly, the nanocomposite showed the most potent antitumor efficacy without obvious systemic toxicity comparing to other control groups with either chemo- or photothermal therapy alone on SW620/Ad300 tumor bearing mice. Altogether, the successful preparation of the nanocomposite and its potent efficacy might provide evidence for the future design and develop of nano-therapeutic system in the treatment of MDR colorectal cancer.

Facile formulation of near-infrared light-triggered hollow mesoporous silica nanoparticles based on mitochondria targeting for on-demand chemo/photothermal/photodynamic therapy

The incorporation of chemo/photothermal/photodynamic therapy in subcellular organelles such as mitochondria has attracted extensive attention recently. Here, we designed mitochondria-targeted hollow mesoporous silica nanoparticles (THMSNs) loaded biocompatible phase-change material L-menthol (LM) via a facile method. Meanwhile, antitumor drug doxorubicin (DOX) and near-infrared (NIR) dye indocyanine green (ICG) approved by FDA were simultaneously encapsulated into THMSNs, denoted as THMSNs@LMDI, which showed NIR radiation triggered capacity for cancer treatment. With the mitochondria-targeted ability of triphenylphosphine, the resulting THMSNs@LMDI showed evidently improved cellular internalization and specific accumulation in mitochondria. Under NIR irradiation, the versatile ICG would be bound to simultaneously produce photodynamic and photothermal therapy. Meanwhile, in view of the solid-liquid phase transition feature of gatekeeper LM, THMSNs@LMDI provided a platform for NIR-mediated temperature-responsive DOX release. As a matter of course, these smart subcellular organelle-THMSNs could serve as an effective drug delivery platform for site-specific on-demand chemo/photothermal/photodynamic therapy of cancer.

Boosting Cancer Therapy with Organelle-Targeted Nanomaterials

The ultimate goal of cancer therapy is to eliminate malignant tumors while causing no damage to normal tissues. In the past decades, numerous nanoagents have been employed for cancer treatment because of their unique properties over traditional molecular drugs. However, lack of selectivity and unwanted therapeutic outcomes have severely limited the therapeutic index of traditional nanodrugs. Recently, a series of nanomaterials that can accumulate in specific organelles (nucleus, mitochondrion, endoplasmic reticulum, lysosome, Golgi apparatus) within cancer cells have received increasing interest. These rationally designed nanoagents can either directly destroy the subcellular structures or effectively deliver drugs into the proper targets, which can further activate certain cell death pathways, enabling them to boost the therapeutic efficiency, lower drug dosage, reduce side effects, avoid multidrug resistance, and prevent recurrence. In this Review, the design principles, targeting strategies, therapeutic mechanisms, current challenges, and potential future directions of organelle-targeted nanomaterials will be introduced.

Mitochondria-Targeted and Resveratrol-Loaded Dual-Function Titanium Disulfide Nanosheets for Photothermal-Triggered Tumor Chemotherapy

A subcellular organelle-targeted delivery of anti-cancer drugs is a promising strategy to maximize the anti-cancer effects and minimize the adverse effects. Herein, we prepared a mitochondria-targeted drug delivery nanoplatform based on IR780 iodide (IR780) and titanium disulfide (TiS2) nanosheets. Due to the large specific surface area of TiS2 nanosheets, the nanoplatform could highly load anti-cancer drug resveratrol (RV). The as-prepared nanocomposite (IR780-TiS2/RV) was used for an efficacious photothermal-triggered tumor chemotherapy. IR780-TiS2/RV showed satisfactory stability and biocompatibility, and the loading ratio of RV and IR780 was about 112% and 56%, respectively. Upon the near-infrared (NIR) irradiation, the heat generated by IR780-TiS2/RV could trigger the RV release. Due to the conjugation with the mitochondria-specific IR780, IR780-TiS2/RV could target and accumulate in mitochondria and release RV when triggered by NIR to decrease the mitochondrial membrane potential, rapidly induce the upregulation of key intrinsic apoptotic factors such as cytochrome c, and initiate the caspase cascade, thereby achieving the chemotherapeutic effect. The IR780-TiS2/RV nanocomposite was demonstrated to have a high anti-tumor efficacy in vitro and in vivo as well as no remarkable tissue toxicity. We believe our study demonstrates that the NIR-triggered IR780-TiS2/RV nanoplatform could be a promising chemotherapeutic agent in clinical practice.

Trackable Water-Soluble Prodrug Micelles Capable of Rapid Mitochondrial-Targeting and Alkaline pH-Responsive Drug Release for Highly Improved Anticancer Efficacy

A trackable water-soluble prodrug conjugate possessing high contents of chlorambucil (Cb) and triphenylphosphonium cation (TPP) was designed and developed after TPP modification on the "branch" of amphipathic prodrugs based on convenient synthesis of heterobifunctional clickable poly(ethylene glycol) (PEG). The aqueous self-assembly of fluorescent polymeric micelles along precise composition can be easily prepared after directly dissolved (DD) in aqueous solution, and exhibit superior cytotoxicity to cancer cells along with highly improved selectivity and sensitivity because of their rapid mitochondrial-targeting and alkaline pH-responsive drug release capabilities. Notably, efficient codelivery of doxorubicin (DOX) for synergistic targeted drug delivery and cancer therapy was achieved.

Enhanced cellular uptake of near-infrared triggered targeted nanoparticles by cell-penetrating peptide TAT for combined chemo/photothermal/photodynamic therapy

Recently, the emergence of cell-penetrating peptides (CPPs) like TAT has greatly improved the efficiency of cancer therapy by enhancing cellular uptake of nanomaterials. Here, we designed a near-infrared (NIR) triggered TAT-based targeted nanoplatform (cRGD@TAT-DINPs), which co-delivered anticancer drug doxorubicin (DOX) and biocompatible dye indocyanine green (ICG) to realize combined chemo/photothermal/photodynamic therapy of cancer in vitro. The resulting nanoparticles showed favorable monodispersity and colloidal stability. Impressively, the DOX could be released in a promoted manner once the nanoparticles were exposed to NIR light. Confocal laser scanning microscopy (CLSM) and flow cytometry analysis demonstrated an immensely enhanced cellular accumulation of DOX after the simultaneous introduction of targeted ligand cRGD and CPP TAT. In addition, the obtained nanoparticles exhibited explosive temperature elevation and reactive oxygen species (ROS) generation mediated by encapsulated ICG under NIR irradiation, and in vitro cytotoxicity assay confirmed the cRGD@TAT-DINPs had an increasing cytotoxicity and excellent synergistic inhibition capacity. Thus, TAT-based nanosystems provide a high-efficient drug delivery strategy for optimizing combined therapy efficiency of cancer.

A novel near-infrared triggered dual-targeted nanoplatform for mitochondrial combined photothermal-chemotherapy of cancer in vitro

A combination of photothermal-chemotherapy has received widespread attention in drug delivery systems for cancer treatment. However, the combination therapy operated in subcellular organelles, such as mitochondria, has been rarely reported. Herein, we designed a novel near-infrared (NIR) triggered dual-targeted nanoplatform (FA/TPP-DINPs) based on mitochondrial combined photothermal-chemotherapy by co-loading FDA-approved NIR dye indocyanine green (ICG) and anticancer drug doxorubicin (DOX). The resulting nanoparticles showed a monodispersed sphere and excellent colloidal stability. Specially, the simultaneous introduction of targeted ligands folic acid (FA) and triphenylphosphine (TPP) to nanoparticles significantly promoted the cellular internalization and mitochondrial co-localization of nanoparticles. Moreover, the encapsulated dye could convert NIR light into heat with high efficiency, which makes the FA/TPP-DINPs an effective platform for mitochondrial combination therapy with chemotherapy drug DOX. Meanwhile, the thermal expansion in response to the change of temperature after sustained 808 nm laser irradiation could cause the disintegration of nanoparticles, which triggered the rapid release of DOX from nanoparticles. As expected, the prepared FA/TPP-DINPs exhibited evidently enhanced cytotoxicity and preeminent combination therapy efficiency on MCF-7 cells. Thus, the NIR triggered dual-targeted nanoplatform provides a new drug delivery strategy for mitochondrial combined photothermal-chemotherapy of cancer.

Design of dual drug-loaded dendrimer/carbon dot nanohybrids for fluorescence imaging and enhanced chemotherapy of cancer cells

Design of powerful nanosystems to overcome multidrug resistance (MDR) for effective chemotherapy of cancer currently remains a great challenge. Herein, we report the development of a poly(amidoamine) (PAMAM) dendrimer/carbon dot nanohybrid for dual drug loading to overcome MDR and simultaneously monitor cancer cells via fluorescence imaging. First, blue-emitting carbon dots (CDs) were synthesized using sodium citrate as a carbon source via the hydrothermal method and used as a carrier to load the anticancer drug doxorubicin (DOX) through non-covalent interactions, thus forming CDs/DOX complexes. In parallel, PAMAM dendrimers of generation 5 (G5) were covalently modified by the targeting ligand cyclic arginine-glycine-aspartic (RGD) peptide and the drug efflux inhibitor d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS). Then, through electrostatic interaction, functional dendrimers (G5-RGD-TPGS) were complexed with CDs/DOX complexes to form a dual drug-loaded nanohybrid system. The dual drug-loaded dendrimer/CD nanohybrids were well characterized. We showed that the nanohybrids possessed good colloidal stability and enabled significant inhibition of cancer cells due to the presence of TPGS, which can inhibit P-glycoprotein (P-gp) by decreasing ATP levels and increasing ROS levels; simultaneously, fluorescence imaging of cancer cells could be achieved in vitro due to the luminescence of CDs. In addition, the attached RGD ligands rendered the nanohybrid with targeting specificity to cancer cells expressing αvβ3 integrin receptors. The developed dual drug-loaded dendrimer/CD nanohybrid may be used as a promising theranostic platform to overcome MDR for enhanced chemotherapy as well as for fluorescence imaging of cancer cells.

Multidrug resistant tumors-aimed theranostics on the basis of strong electrostatic attraction between resistant cells and nanomaterials

The gene expression of resistant cells usually raises the negative potential of cell membranes. Utilizing the strong electrostatic attraction of resistant cells with nanomaterials, multidrug resistance tumors-aimed theranostics is demonstrated.

Long-Circulating Amphiphilic Doxorubicin for Tumor Mitochondria-Specific Targeting

The mitochondria have emerged as a novel target for cancer chemotherapy primarily due to their central roles in energy metabolism and apoptosis regulation. Here, we report a new molecular approach to achieve high levels of tumor- and mitochondria-selective deliveries of the anticancer drug doxorubicin. This is achieved by molecular engineering, which functionalizes doxorubicin with a hydrophobic lipid tail conjugated by a solubility-promoting poly(ethylene glycol) polymer (amphiphilic doxorubicin or amph-DOX). In vivo, the amphiphile conjugated to doxorubicin exhibits a dual function: (i) it binds avidly to serum albumin and hijacks albumin's circulating and transporting pathways, resulting in prolonged circulation in blood, increased accumulation in tumor, and reduced exposure to the heart; (ii) it also redirects doxorubicin to mitochondria by altering the drug molecule's intracellular sorting and transportation routes. Efficient mitochondrial targeting with amph-DOX causes a significant increase of reactive oxygen species levels in tumor cells, resulting in markedly improved antitumor efficacy than the unmodified doxorubicin. Amphiphilic modification provides a simple strategy to simultaneously increase the efficacy and safety of doxorubicin in cancer chemotherapy.

Updates in Anthracycline-Mediated Cardiotoxicity

Cardiotoxicity is one of the main adverse effects of chemotheraphy, affecting the completion of cancer therapies and the short- and long-term quality of life. Anthracyclines are currently used to treat many cancers, including the various forms of leukemia, lymphoma, melanoma, uterine, breast, and gastric cancers. World Health Organization registered anthracyclines in the list of essential medicines. However, anthracyclines display a major cardiotoxicity that can ultimately culminate in congestive heart failure. Taking into account the growing rate of cancer survivorship, the clinical significance of anthracycline cardiotoxicity is an emerging medical issue. In this review, we focus on the key progenitor cells and cardiac cells (cardiomyocytes, fibroblasts, and vascular cells), focusing on the signaling pathways involved in cellular damage, and the clinical biomarkers in anthracycline-mediated cardiotoxicity.

Triphenylphosphonium-modified mitochondria-targeted paclitaxel nanocrystals for overcoming multidrug resistance

Mitochondria are currently known as novel targets for treating cancer, especially for tumors displaying multidrug resistance (MDR). This present study aimed to develop a mitochondria-targeted delivery system by using triphenylphosphonium cation (TPP⁺)-conjugated Brij 98 as the functional stabilizer to modify paclitaxel (PTX) nanocrystals (NCs) against drug-resistant cancer cells. Evaluations were performed on 2D monolayer and 3D multicellular spheroids (MCs) of MCF-7 cells and MCF-7/ADR cells. In comparison with free PTX and the non-targeted PTX NCs, the targeted PTX NCs showed the strongest cytotoxicity against both 2D MCF-7 and MCF-7/ADR cells, which was correlated with decreased mitochondrial membrane potential. The targeted PTX NCs exhibited deeper penetration on MCF-7 MCs and more significant growth inhibition on both MCF-7 and MCF-7/ADR MCs. The proposed strategy indicated that the TPP⁺-modified NCs represent a potentially viable approach for targeted chemotherapeutic molecules to mitochondria. This strategy might provide promising therapeutic outcomes to overcome MDR.

Multifunctional Nanosystem for Targeted and Controlled Delivery of Multiple Chemotherapeutic Agents for the Treatment of Drug-Resistant Breast Cancer

By targeting CD44 receptors, inhibiting multidrug resistance (MDR), controlling drug release, and synergistically inhibiting tumor growth, a multilayered nanosystem was developed to serve as a multifunctional platform for the treatment of drug-resistant breast cancers. The multilayer nanosystem is composed of a poly(lactic-co-glycolic acid) core, a liposome second layer, and a chitosan third layer. The chitosan-multilayered nanoparticles (Ch-MLNPs) can co-deliver three chemotherapeutic agents: doxorubicin (DOX), paclitaxel (PTX), and silybin. The three drugs are released from the multilayered NPs in a controlled and sequential manner upon internalization and localization in the cellular endosomes. The presence of a chitosan layer allows the nanosystem to target a well-characterized MDR breast cancer biomarker, the CD44s receptor. In vitro cytotoxicity study showed that the nanosystem loaded with triple drugs, DOX-PTX-silybin, resulted in better antitumor efficacy than the single-drug or dual-drug nano-formulations. Likely attributed to the MDR-inhibition effect of silybin, the co-delivered DOX and PTX exhibited a better synergistic effect on MDR breast cancer cells than on non-MDR breast cancer cells. The in vivo study also showed that the multilayered nanosystem promoted MDR inhibition and synergy between chemotherapeutic agents, leading to significant tumor reduction in a xenograft animal model. Ch-MLNPs reduced the tumor volume by fivefold compared to that of the control group without causing overt cytotoxicity.

Mitochondrial-Targeting Anticancer Agent Conjugates and Nanocarrier Systems for Cancer Treatment

The mitochondrion is an important intracellular organelle for drug targeting due to its key roles and functions in cellular proliferation and death. In the last few decades, several studies have revealed mitochondrial functions, attracting the focus of many researchers to work in this field over nuclear targeting. Mitochondrial targeting was initiated in 1995 with a triphenylphosphonium-thiobutyl conjugate as an antioxidant agent. The major driving force for mitochondrial targeting in cancer cells is the higher mitochondrial membrane potential compared with that of the cytosol, which allows some molecules to selectively target mitochondria. In this review, we discuss mitochondria-targeting ligand-conjugated anticancer agents and their in vitro and in vivo behaviors. In addition, we describe a mitochondria-targeting nanocarrier system for anticancer drug delivery. As previously reported, several agents have been known to have mitochondrial targeting potential; however, they are not sufficient for direct application for cancer therapy. Thus, many studies have focused on direct conjugation of targeting ligands to therapeutic agents to improve their efficacy. There are many variables for optimal mitochondria-targeted agent development, such as choosing a correct targeting ligand and linker. However, using the nanocarrier system could solve some issues related to solubility and selectivity. Thus, this review focuses on mitochondria-targeting drug conjugates and mitochondria-targeted nanocarrier systems for anticancer agent delivery.

Biocompatible fluorescent carbon quantum dots prepared from beetroot extract for in vivo live imaging in C. elegans and BALB/c mice

Luminescent carbon quantum dots (CQDs) prepared from aqueous beetroot extract were developed as unique fluorescent nanomaterials for in vivo live animal imaging applications. Blue (B) and green (G) emitting environmentally benign CQDs (particle size of 5 nm and 8 nm, respectively) exhibited bright fluorescence in aqueous medium and were found to be biocompatible, photostable and non-toxic in animal models. The in vivo imaging and toxicity evaluation of both CQDs were performed for the first time in the Caenorhabditis elegans (C. elegans) model, which revealed consistent fluorescence in the gut tissues of the worms without exerting any sign of toxic effects on the nematodes. The in vivo bio-distribution of G-CQDs given by tail vein injection in live BALB/c mice showed optical signals in the lower abdominal regions, mainly in the intestine, and cleared from the body through faeces. The tremendous potential shown by these eco-friendly CQDs in the C. elegans and mice models advocates new hopes for greener CQD nanomaterials as diagnostic tools in the biomedical field.

Overcoming Multidrug Resistance through the GLUT1-Mediated and Enzyme-Triggered Mitochondrial Targeting Conjugate with Redox-Sensitive Paclitaxel Release

Multidrug resistance (MDR) is thought to be the major obstacle leading to the failure of paclitaxel (PTX) chemotherapy. To solve this problem, a glucose transporter-mediated and matrix metalloproteinase 2 (MMP2)-triggered mitochondrion-targeting conjugate [glucose-polyethylene glycol (PEG)-peptide-triphenylphosponium-polyamidoamine (PAMAM)-PTX] composed of a PAMAM dendrimer and enzymatic detachable glucose-PEG was constructed for mitochondrial delivery of PTX. The conjugate was characterized by a 30 nm sphere particle, MMP2-sensitive PEG outer layer detachment from PAMAM, and glutathione (GSH)-sensitive PTX release. It showed higher cellular uptake both in glucose transporter 1 (GLUT1) overexpressing MCF-7/MDR monolayer cell (2D) and multicellular tumor spheroids (3D). The subcellular location study showed that it could specifically accumulate in the mitochondria. Moreover, it exhibited higher cytotoxicity against MCF-7/MDR cells, which significantly reverse the MDR of MCF-7/MDR cells. The MDR reverse might be caused by reducing the ATP content through destroying the mitochondrial membrane as well as by down-regulating P-gp expression. In vivo imaging and tissue distribution indicated more conjugate accumulated in the tumor of the tumor-bearing mice model. Consequently, the conjugate showed better tumor inhibition rate and lower body weight loss, which demonstrated that it possessed high efficiency and low toxicity. This study provides glucose-mediated GLUT targeting, MMP2-responsive PEG detachment, triphenylphosponium-mediated mitochondria targeting, and a GSH-sensitive intracellular drug release conjugate that has the potential to be exploited for overcoming MDR of PTX.

A tumor-mitochondria dual targeted aza-BODIPY-based nanotheranostic agent for multimodal imaging-guided phototherapy

Mitochondria targeted phototherapy, including photodynamic therapy (PDT) and photothermal therapy (PTT), has excelled as an effective approach among other non-specific techniques for its high selectivity, non-invasiveness and low systemic toxicity.

Mitochondria targeting IR780-based nanoGUMBOS for enhanced selective toxicity towards cancer cells

Herein, a simple counter-ion variation strategy is proposed and demonstrated for design of an array of near infrared IR780-based nanoGUMBOS (nanomaterials from a Group of Uniform Materials Based on Organic Salts) to produce enhanced anticancer activity. These nanomaterials were synthesized by direct nanoengineering of IR780-based GUMBOS using a reprecipitation method, without addition of any other materials. Thus, these novel nanomaterials can serve as carrier-free nanodrugs, providing several distinct advantages over conventional chemotherapeutics. Examination of the size and stability of these nanoGUMBOS indicates formation of approximately 100 nm nanoparticles that are stable under biological conditions. Interestingly, in vitro chemotherapeutic applications of these nanoGUMBOS indicate two to four-fold enhanced toxicity towards breast cancer cells as compared to the parent dye, while still maintaining minimal toxicity towards normal cells. The mechanism of cancer toxicity for these nanoGUMBOS was also examined by a study of their sub-cellular localization as well as using a mitochondrial toxicity assay. Analyses of data from these studies revealed that all nanoGUMBOS primarily accumulate in the mitochondria of cancer cells and produce dysfunction in the mitochondria to induce cell death. Using these studies, we demonstrate tunable properties of IR780-based nanoGUMBOS through simple variation of counter-ions, thus providing a promising strategy for future design of better nanomedicines to be used for cancer therapy.

Mitochondria targeting nanoGUMBOS were successfully fabricated based on self-assembly of IR780 GUMBOS with different counter-anions that show promising anticancer effects.

Luminescence carbon dot-based nanofibers for a water-insoluble drug release system and their monitoring of drug release

Drug release systems with fluorescence detection have emerged as a potential application for the biological area of diagnosis and therapy.

Recent developments in d-α-tocopheryl polyethylene glycol-succinate-based nanomedicine for cancer therapy

Cancer remains an obstacle to be surmounted by humans. As an FDA-approved biocompatible drug excipient, d-α-tocopheryl polyethylene glycol succinate (TPGS) has been widely applied in drug delivery system (DDS). Along with in-depth analyses of TPGS-based DDS, increasingly attractive results have revealed that TPGS is able to act not only as a simple drug carrier but also as an assistant molecule with various bio-functions to improve anticancer efficacy. In this review, recent advances in TPGS-based DDS are summarized. TPGS can inhibit P-glycoprotein, enhance drug absorption, induce mitochondrial-associated apoptosis or other apoptotic pathways, promote drug penetration and tumor accumulation, and even inhibit tumor metastasis. As a result, many formulations, by using original TPGS, TPGS-drug conjugates or TPGS copolymers, were prepared, and as expected, an enhanced therapeutic effect was achieved in different tumor models, especially in multidrug resistant and metastatic tumors. Although the mechanisms by which TPGS participates in such functions are not yet very clear, considering its effectiveness in tumor treatment, TPGS-based DDS appears to be one of the best candidates for future clinical applications.