Nuclear-uptake nanodrug delivery system for drug-resistant cancer therapy

The development of multidrug resistance(MDR)has become an increasingly serious problem in cancer therapy,making the long-term survival of patients with MDRassociated cancers extremely challenging.The cell-membrane overexpression of P-glycoprotein(P-gp),which can actively efflux various anticancer drugs from the cell,is a major mechanism of MDR.Nuclear-uptake nanodrug delivery systems,which enable intranuclear release of anticancer drugs,are expected to address this challenge by by-     

Cathepsin B-responsive nanodrug delivery systems for precise diagnosis and targeted therapy of malignant tumors

The tumor microenvironment (TME) significantly influences cancer evolution and therapeutic efficacy. Targeting biofunctional molecules to the TME has long been appreciated as a means of raising local drug concentrations and reducing systemic toxicities. The booming nanotechnology field has realized the importance of cathepsin B to derive a variety of intelligent enzyme-responsive nanosized drug delivery systems (nanoDDS) to improve treatment responses and clinical outcomes. In this tutorial review, after introducing the molecular structure and physiological/pathological functions of cathepsin B, the outstanding achievements of cathepsin B-responsive nanoplatforms in the precise diagnosis, targeted therapy, and synergistic theranostics of malignant tumors are systematically described. Finally, the challenges of enzyme-substrate incompatibility, low diagnostic sensitivity, mass production and biocompatibility of multifunctional nanoDDS are considered in order to successfully promote them to clinical applications.     

Cathepsin B-responsive nanodrug delivery systems for precise diagnosis and targeted therapy of malignant tumors

The tumor microenvironment (TME) significantly influences cancer evolution and therapeutic efficacy. Targeting biofunctional molecules to the TME has long been appreciated as a means of raising local drug concentrations and reducing systemic toxicities. The booming nanotechnology field has realized the importance of cathepsin B to derive a variety of intelligent enzyme-responsive nanosized drug delivery systems (nanoDDS) to improve treatment responses and clinical outcomes. In this tutorial review, after introducing the molecular structure and physiological/pathological functions of cathepsin B, the outstanding achievements of cathepsin B-responsive nanoplatforms in the precise diagnosis, targeted therapy, and synergistic theranostics of malignant tumors are systematically described. Finally, the challenges of enzyme-substrate incompatibility, low diagnostic sensitivity, mass production and biocompatibility of multifunctional nanoDDS are considered in order to successfully promote them to clinical applications     

Development of a thermal neutron-sensitive liposome for a novel drug delivery system aiming for radio-chemo-concurrent cancer therapy

A thermal neutron-sensitive liposome has been developed focusing on irradiation site-specific-controlled release of a medicine. We recommended a ¹⁰B-borocaptate dimer as a detonator of liposome in expectation of effects of low-energy heavy ions produced by ¹⁰B(n, α)⁷Li reaction. As a result, an X-ray-sensitive liposome incorporating the detonator was vulnerable enough to release an anticancer agent, carboplatin, at a dose/dose–rate near clinical use. These results reveal, moreover, that the liposomes are also applicable to a heavy-ion beam.     

Glutathione-triggered non-template synthesized porous carbon nanospheres serve as low toxicity targeted delivery system for cancer multi-therapy

Nanomaterial based drug delivery system have received great attention in clinical application due to their high therapeutic efficacy and lower side effects than classical method, multi-functional nanomaterial also have shown the excellent performance at cancer theranostic and durg tracking in vivo and in vitro. However, most of these works are influenced by the bio-toxicity of applied nanomaterials, which could influence the diagnostic results and treatment effect. Therefore, we have prepared a high biocompatibility porous carbon nanospheres (PCNs) based nano-system (PCN-siRNA-DOX-FA) for targeted drug delivery and theranostic. The surface modifications have increased dispersion and stability of the PCNs, and folic acid (FA) had enhanced the active target ability for FA receptor positive cell lines. Moreover, through the siRNA structure and doxorubicin (DOX) loading, biological and chemical combined multi-therapy was achieved in cancerous cells. This constructed nano-system could positively improve the biotoxicity problem of nanomaterial and provide a potential platform for clinical cancer theranostic applications.     

Catechol polymers for pH-responsive, targeted drug delivery to cancer cells

A novel cell-targeting, pH-sensitive polymeric carrier was employed in this study for delivery of the anticancer drug bortezomib (BTZ) to cancer cells. Our strategy is based on facile conjugation of BTZ to catechol-containing polymeric carriers that are designed to be taken up selectively by cancer cells through cell surface receptor-mediated mechanisms. The polymer used as a building block in this study was poly(ethylene glycol), which was chosen for its ability to reduce nonspecific interactions with proteins and cells. The catechol moiety was exploited for its ability to bind and release borate-containing therapeutics such as BTZ in a pH-dependent manner. In acidic environments, such as in cancer tissue or the subcellular endosome, BTZ dissociates from the polymer-bound catechol groups to liberate the free drug, which inhibits proteasome function. A cancer-cell-targeting ligand, biotin, was presented on the polymer carriers to facilitate targeted entry of drug-loaded polymer carriers into cancer cells. Our study demonstrated that the cancer-targeting drug-polymer conjugates dramatically enhanced cellular uptake, proteasome inhibition, and cytotoxicity toward breast carcinoma cells in comparison with nontargeting drug-polymer conjugates. The pH-sensitive catechol-boronate binding mechanism provides a chemoselective approach for controlling the release of BTZ in targeted cancer cells, establishing a concept that may be applied in the future toward other boronic acid-containing therapeutics to treat a broad range of diseases.     

Toward a new generation of therapeutics: artificial cell targeted delivery of live cells for therapy

Scientific evidence in the prevention and treatment of various disorders is accumulating regarding probiotics. The health benefits supported by adequate clinical data include increased resistance to infectious disease, decreased duration of diarrhea, management of inflammatory bowel disease, reduction of serum cholesterol, prevention of allergy, modulation of cytokine gene expression, and suppression of carcinogen production. Recent ventures in metabolic engineering and heterologous protein expression have enhanced the enzymatic and immunomodulatory effects of probiotics and, with time, may allow more active intervention among critical care patients. In addition, a number of approaches are currently being explored, including the physical and chemical protection of cells, to increase probiotic viability and its health benefits. Traditional immobilization of probiotics in gel matrices, most notably calcium alginate and kappa-carrageenan, has frequently been employed, with noted improvements in viability during freezing and storage. Conflicting reports exist, however, on the protection offered by immobilization from harsh physiologic environments. An alternative approach, microencapsulation in "artificial cells," builds on immobilization technologies by combining enhanced mechanical stability of the capsule membrane with improved mass transport, increased cell loading, and greater control of parameters. This review summarizes the current clinical status of probiotics, examines the promises and challenges of current immobilization technologies, and presents the concept of artificial cells for effective delivery of therapeutic bacterial cells.     

A simple synthesis of a targeted drug delivery system with enhanced cytotoxicity

A simple synthesis of a targeted drug delivery system with enhanced cytotoxicity to (epidermal growth factor receptor) EGFR(+) cancer cells.     

Colloidal gold modified with a genetically engineered nitroreductase: toward a novel enzyme delivery system for cancer prodrug therapy

Directed enzyme prodrug therapy is an extensive area of research in cancer chemotherapy. Although very promising, the current directed approaches are still hampered by inefficient enzyme expression and tumor targeting. This work investigates the viability of using metal nanoparticles as a novel delivery vehicle for prodrug-activating enzymes. Using genetically incorporated amino acid sequences, a nitroreductase from E. coli was directly immobilized onto a 50 nm gold colloid, as confirmed by gel electrophoresis, DLS, and UV-vis spectroscopy. The resulting conjugates showed excellent stability in changing proton and sodium chloride environments, including PBS at 37 °C. Remarkably, the immobilized nitroreductase retained more than 99% activity to the CB1954 prodrug without the need for stabilizers. This work provides the foundation for attaching prodrug-activating enzymes to metal nanoparticles for future use in directed enzyme prodrug therapy.     

Hyper-branched multifunctional carbon nanotubes carrier for targeted liver cancer therapy

The systemic toxicity of anticancer drugs regularly restricts the use of conventional chemotherapy to treat cancer. In this study, the limitations overcome by profitably fabricating a multifunctional nanocarrier system to carry the anticancer drug into the specific location of the cancer cells. The polyethylene glycol (PEG) was functionalized in the carboxylated multiwalled carbon nanotubes (MWCNT-COOH) through an esterification reaction (MWCNT-PEG). The targeting ligand of folic acid (FA) was covalently bonded with hyperbranched poly-L-lysine (HBPLL) using adipic acid (AA) as a cross-linking agent. Doxorubicin (DOX), an anticancer drug, was effectively loaded on MWCNT-PEG-AA-HBPLL-FA carrier loading, and in-vitro drug release was investigated by UV–Vis spectrophotometer. The chemical functionalization, morphological properties, crystalline nature, surface charge, and thermal stability of the synthesized materials were studied by FT-IR, FE-SEM, HR-TEM, DLS, and TGA techniques. In-vitro cytotoxicity and anticancer properties of DOX-loaded nanocarrier were studied in human liver cancer (HepG2) cells and human embryonic kidney (HEK293) cells. The activities of caspases (caspase ?3, ?8 & ?9) were analyzed using luminometry. The intrinsic apoptosis pathway proteins (Bcl-2 & BAX) were determined by western blot and RT-PCR analysis. The synthesized DOX-loaded nanocarriers exhibited increased cytotoxicity and apoptosis in liver HepG2 cells. The results suggest that the DOX-loaded nanocarrier possesses strong anticancer properties and could be an applicable and potential drug carrier for liver cancer chemotherapy.     

Bio-assembled smart nanocapsules for targeted delivery of KRAS shRNA and cancer cell bioimage

The five-year survival rate for pancreatic cancer is less than 5%. However, the current clinical multimodal therapy combined with first-line chemotherapy drugs only increases the patient's median survival from 5.0 months to 7.2 months. Consequently, a new strategy of cancer treatments is urgently needed to overcome this high-fatality disease. Through a series of biometric analyses, we found that KRAS is highly expressed in the tumor of pancreatic cancer patients, and this high expression is closely related to the poor prognosis of patients. It shows that inhibiting the expression of KRAS has great potential in gene therapy for pancreatic cancer. Given those above, we have exploited the possibility of targeted delivery of KRAS shRNA with the intelligent and bio-responsive nanomedicine to detect the special oxidative stress microenvironment of cancer cells and realize efficient cancer theranostics. Our observations demonstrate that by designing the smart self-assembled nanocapsules of melanin with fluorescent nanoclusters we can readily achieve the bio-recognition and bioimaging of cancer cells in biological solution or serum. The self-assembled nanocapsules can make a significant bio-response to the oxidative stress microenvironment of cancer cells and generate fluorescent zinc oxide Nanoclusters in situ for targeted cell bioimaging. Moreover, it can also readily facilitate cancer cell suppression through the targeted delivery of KRAS shRNA and low-temperature hyperthermia. This raises the possibility to provide a promising theranostics platform and self-assembled nanomedicine for targeted cancer diagnostics and treatments through special oxidative stress-responsive effects of cancer cells.     

Thermoresponsive polymer colloids for drug delivery and cancer therapy

Many difficulties in treating cancer arise from the problems in directing highly cytotoxic agents to the deseased tissues, cells and intracellular compartments. Many drug delivery systems have been devised to address this problem, including those that show a change in properties in response to a temperature stimulus. In particular, colloidal materials based on thermoresponsive polymers offer a means to transport drugs selectively into tumour tissues that are hyperthermic, either intrinsically or through the application of clinical procedures such as localised heating. In this paper, the key attributes of thermoresponsive polymer colloids are considered, a number of important recent examples are discussed and the possible future developments of these materials are evaluated.     

Folic acid and its derivatives for targeted photodynamic therapy of cancer

The fundamentals of folic acid and folate receptors functioning in the body, changes in the expression level of folate receptors in carcinogenesis, as well as use of folic acid and its derivatives for targeted delivery of photosensitizers to tumors have been reviewed. The ways of increasing the efficacy of photodynamic therapy by creating multifunctional nanoplatforms that ensure both passive targeting and receptor-mediated internalization of photosensitizers in tumor cells have been discussed.     

pH‐sensitive carbon quantum dots−doxorubicin nanoparticles for tumor cellular targeted drug delivery

A kind of pH‐responsive carbon quantum dots?doxorubicin nanoparticles drug delivery platform (D‐Biotin/DOX‐loaded mPEG‐OAL/N‐CQDs) was designed and synthesized. The system consists of fluorescent carbon dots as cross‐linkers, and D‐Biotin worked as targeting groups, which made the system have a pH correspondence, doxorubicin hydrochloride (DOX) as the target drug, oxidized sodium alginate (OAL) as carrier materials. Ultraviolet (UV)‐Vis spectrum showed that the drug‐loading rate of DOX is 10.5%, and the drug release in vitro suggested that the system had a pH response and tumor cellular targeted, the drug release rate is 65.6% at the value of pH is 5.0, which is much higher than that at the value of pH is 7.4. The cytotoxicity test and laser confocal fluorescence imaging showed that the synthesized drug delivery system has high cytotoxicity to cancer cells, and the drug‐loaded nanoparticles could enter the cells through endocytosis.     

Zirconium phosphate nano-platelets: a novel platform for drug delivery in cancer therapy

Doxorubicin was intercalated into novel zirconium phosphate nano-platelets (ZrP). The obtained doxorubicin intercalated ZrP nano-platelets had an impressive 34.9% (w/w) drug loading. We used this material to deliver doxorubicin to breast cancer cells (MCF-7). Cellular studies with MCF-7 cells showed higher uptake and cytotoxicity of doxorubicin loaded ZrP compared to free doxorubicin.     

Mapping blood biochemistry by Raman spectroscopy at the cellular level

We report how Raman difference imaging provides insight on cellular biochemistry in vivo as a function of sub-cellular dimensions and the cellular environment. We show that this approach offers a sensitive diagnostic to address blood biochemistry at the cellular level. We examine Raman microscopic images of the distribution of the different hemoglobins in both healthy (discocyte) and unhealthy (echinocyte) blood cells and interpret these images using pre-calculated, accurate pre-resonant Raman tensors for scattering intensities specific to hemoglobins. These tensors are developed from theoretical calculations of models of the oxy, deoxy and met forms of heme benchmarked against the experimental visible spectra of the corresponding hemoglobins. The calculations also enable assignments of the electronic transitions responsible for the colour of blood: these are mainly ligand to metal charge transfer transitions.

We assign the electronic transitions responsible for the colour of blood and present a Raman imaging diagnostic approach for individual blood cells.     

Construction of a biotin-targeting drug delivery system and its near-infrared theranostic fluorescent probe for real-time image-guided therapy of lung cancer

The therapy of non-small lung cancer(NSCLC) is limited by wide metastasis and chemotherapy resistance, herein, we present a new cancer-targeting prodrug PBG with the integration of real-time fluorescence visualization. The potent anticancer drug Gefitinib conjugates a biotin recognition ligand yielding the prodrug PBG via a GSH-activatable disulfide bond linker. Once coupling a near-infrared azo-BODIPY fluorophore into the molecular structure of PBG, we obtain its fluorescent theranostic TBG. Th...     

Efficient nano-enabled therapy for gastrointestinal cancer using silicasome delivery technology

Science China Chemistry - The gastrointestinal tract is an eight-meter-long pathway that includes various organs, which runs from the mouth to the anus. Under certain pathological circumstances,...     

An optimized RGD-decorated micellar drug delivery system for albendazole for the treatment of ovarian cancer: from RAFT polymer synthesis to cellular uptake

Block copolymers were prepared via RAFT polymerization with P(PEGMEMA) as the hydrophilic block to form micelles for the controlled delivery of ABZ. The group contribution method was used to estimate the partial solubility parameters for ABZ and various polymers as potential core‐forming block to achieve optimum compatibility. Different ratios between MMA and LMA, a non‐compatible monomer, were prepared. Cytotoxicity tests revealed a high toxicity of the ABZ‐loaded micelle resulting in 80% cell deaths at a micelle concentration of 10 µg · mL^?1. Cellular uptake of micelles has been studied using fluorescently labeled micelles, showing that a large fraction of micelles is readily taken up by OVCAR‐3 cells. RGD‐conjugated micelles were prepared and showed an increased cellular uptake.