The ultimate goal in cancer therapy and diagnosis is to achieve highly specific targeting to cancer cells. Coated with the source cancer cell membrane specifically derived from the homologous tumors, the nanoparticles are identified with the self-recognition internalization by the source cancer cell lines in vitro and the highly tumor-selective targeting "homing" to the homologous tumor in vivo even in the competition of another heterologous tumor. As the result, MNP@DOX@CCCM nanovehicle showed strong potency for tumor treatment in vivo and the MR imaging. This bioinspired strategy shows great potential for precise therapy/diagnosis of various tumors merely by adjusting the cell membrane source accordingly on the nanoparticle surface.
Direct delivery of proteins into cells avoids many drawbacks of gene delivery, and thus has emerging applications in biotherapy. However, it remains a challenging task owing to limited charges and relatively large size of proteins. Here, we report an efficient protein delivery system via the co-assembly of fluoroamphiphiles and proteins into nanoparticles. Fluorous substituents on the amphiphiles play essential roles in the formation of uniform nanoparticles, avoiding protein denaturation, efficient endocytosis, and maintaining low cytotoxicity. Structure-activity relationship studies reveal that longer fluorous chain length and higher fluorination degree contribute to more efficient protein delivery, but excess fluorophilicity on the polymer leads to the pre-assembly of fluoroamphiphiles into stable vesicles, and thus failed protein encapsulation and cytosolic delivery. This study highlights the advantage of fluoroamphiphiles over other existing strategies for intracellular protein delivery.
Redox control in the mitochondrion is essential for the proper functioning of this organelle. Disruption of mitochondrial redox processes contributes to a host of human disorders, including cancer, neurodegenerative diseases, and aging. To better characterize redox control pathways in this organelle, we have targeted a green fluorescent protein-based redox sensor to the intermembrane space (IMS) and matrix of yeast mitochondria. This approach allows us to separately monitor the redox state of the matrix and the IMS, providing a more detailed picture of redox processes in these two compartments. To verify that the sensors respond to localized glutathione (GSH) redox changes, we have genetically manipulated the subcellular redox state using oxidized GSH (GSSG) reductase localization mutants. These studies indicate that redox control in the cytosol and matrix are maintained separately by cytosolic and mitochondrial isoforms of GSSG reductase. Our studies also demonstrate that the mitochondrial IMS is considerably more oxidizing than the cytosol and mitochondrial matrix and is not directly influenced by endogenous GSSG reductase activity. These redox measurements are used to predict the oxidation state of thiolcontaining proteins that are imported into the IMS.
In this paper, a self‐delivery system PpIX‐PEG‐(KLAKLAK)2 (designated as PPK) is fabricated to realize mitochondria‐targeted photodynamic tumor therapy. It is found that the PPK self‐delivery system exhibited high drug loading efficacy as well as novel capacity in generation of intracellular reactive oxygen species (ROS). This study also indicated that the photochemical internalization effect of the photosensitizer protoporphyrin IX (PpIX) under a short time light irradiation improved the cellular internalization of PPK. On the contrary, PPK could target to the subcellular organelle mitochondria due to the presence of proapoptosis (KLAKLAK)2 peptide. Importantly, the in situ generation of ROS in mitochondria enhanced the photodynamic therapy efficacy under another long time irradiation, leading to significant cell death with decreased mitochondrial membrane potential. Besides, relative high tumor accumulation, minimal systemic cytotoxicity and efficacious long‐term tumor inhibition in vivo are also confirmed by using a murine model. All these results demonstrated the self‐delivery system PPK with a dual‐stage light irradiation strategy is a promising nanoplatform for tumor treatment.
Recent advances in nanomaterials for enhanced therapeutic efficacy of photothermal therapy in tumor treatment were highlighted.
CONTENTS 1. Introduction 3856 2. Theoretical Background of NMR Analysis 3858 2.1. Chemical Shift Titrations 3858 2.2. NOE Measurements 3859 2.3. Diffusion Analysis 3859 2.3.1. PGSE Diffusion Measurements 3859 2.3.2. DOSY 3860 2.4. Relaxation Measurements 3860 2.5. STD 3860 3. Applications of NMR Techniques in the Analysis of Dendrimer-Based Host−Guest Systems 3863 3.1. Interaction Mechanisms in Dendrimer-Based Host−Guest Systems 3863 3.2. Calculation of Binding Parameters in Dendrimer-Based Host−Guest Systems 3866 3.3. Competitive Binding of Guest Molecules on the Surface or in the Interior of Dendrimers 3870 3.4. Localization of the Guests in Dendrimer/ Guest Complexes 3874 3.5. High-Throughput Screening of Dendrimer-Binding Drugs 3877 3.6. Size Determination of the Nanoparticles Synthesized within Dendrimer 3880 3.7. Supramolecular Structure of Dendrimer/ Surfactant Aggregates 3881 3.8. Dendrimer-Based MRI Contrasts 3884 4. Conclusions 3885 Author Information 3886 Corresponding Author 3886 Notes 3886 Biographies 3886 Acknowledgments 3886 List of Abbreviations 3886 References 3887
Polymeric nanoparticles that can stably load anticancer drugs and release them in response to a specific trigger such as glutathione are of great interest in cancer therapy. In the present study, dendrimer-encapsulated gold nanoparticles (DEGNPs) were synthesized and used as carriers of thiolated anticancer drugs. Thiol-containing drugs such as captopril and 6-mercaptopurine loaded within DEGNPs showed an "Off−On" release behavior in the presence of thiol-reducing agents such as glutathione and dithiothreitol. Thiolated doxorubicin and cisplatin, loaded within the nanoparticle, showed much reduced cytotoxicity as compared to the free anticancer compounds. The toxicity of drug-loaded DEGNPs can be enhanced by improving the intracellular glutathione. Glutathione-triggered release of thiolated doxorubicin within cancer cells is further confirmed by flow cytometry and confocal laser scan microscopy studies. In addition, DEGNPs showed excellent biocompatibility on several cell lines. This study provides a new insight into biomedical applications of dendrimers and dendrimer-encapsulated nanoparticles.
The host-guest chemistry of dendrimer-drug complexes is investigated by NMR techniques, including (1)H NMR and 2D-NOESY studies. The effects of molecular properties of drug molecules (protonation ability and spatial steric hindrance of charged groups) and surface functionalities of dendrimers (positively charged amine groups and negatively charged carboxylate groups) on the host-guest interactions are discussed. Different interaction mechanisms between dendrimers and drug molecules are proposed on the basis of NMR results. Primary amine- and secondary amine-containing drugs preferentially bind to negatively charged dendrimers by strong electrostatic interactions, whereas tertiary amine and quaternary ammonium-containing drugs have weak binding ability with dendrimers due to relatively low protonation ability of the tertiary amine group and serious steric hindrance of the quaternary ammonium group. Positively charged drugs locate only on the surface of negatively charged dendrimers, whereas negatively charged drugs locate both on the surface and in the interior cavities of positively charged dendrimers. The host-guest chemistry of dendrimer-drug complexes is promising for the development of new drug delivery systems.
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