A novel curcumin-loaded composite dressing facilitates wound healing due to its natural antioxidant effect.

PURPOSE: To prepare a novel wound dressing to facilitate cutaneous wound healing. METHODS: Curcumin (Cur) was added to the ring-shaped ß-cyclodextrin (CD) to form a ß-CD-Cur inclusion complex (CD-Cur). CD-Cur was then integrated into a composite chitosan-alginate (CA) mix. Finally, CA-CD-Cur was generated with a freeze-drying technique. Water-uptake capacity, degradation rate, and drug-release kinetics of the newly formed dressing were investigated in vitro. In animal studies, cutaneous wounds in rats were created, treated with CA-CD-Cur, then compared to CA-Cur, CA, and gauze. RESULTS: CA-CD-Cur-treated wounds showed accelerated closure rates, improved histopathological results, and lower SOD, lipid peroxidation, pI3K, and pAktkt levels than other groups. On the contrary, catalase, IκBα, and TGFß1 levels were higher than others. CONCLUSION: CA-CD-Cur may facilitate cutaneous wound dressing that facilitate wound healing.

Peptide and Aptamer Decorated Delivery System for Targeting Delivery of Cas9/sgRNA Plasmid To Mediate Antitumor Genome Editing.

A multiple-functionalized targeting delivery system was prepared by self-assembly for efficient delivery of Cas9/sgRNA plasmids to targeted tumor cell nuclei. The Cas9/sgRNA plasmids were compacted by protamine in the presence of calcium ions to form nanosized cores, which were further decorated by peptide and aptamer conjugated alginate derivatives. With the help of the nuclear location signal peptide and AS1411 aptamer with specific affinity for nucleolin in the tumor cell membrane and nuclei, the delivery vector can specifically deliver the plasmid to the nuclei of tumorous cells for knocking out the protein tyrosine kinase 2 (PTK2) gene to down-regulate focal adhesion kinase (FAK). The tumor cell apoptosis induced by genome editing is mitochondrial-dependent. In addition, FAK knockout results in negative regulation on the PI3K/AKT signaling pathway. Meanwhile, favorable modulation on various proteins involved in tumor progression can be realized by genome editing. The enhanced E-cadherin and decreased MMPs, vimentin, and VEGF imply the desirable effects of genome editing on suppression of tumor development. Wound healing and transwell assays confirm that the genome editing system can suppress tumor invasion and metastasis in edited cells efficiently. The investigation provides a facile and effective strategy to fabricate multiple-functionalized delivery vectors for genome editing.

Targeting Delivery of Oligodeoxynucleotides to Macrophages by Mannosylated Cationic Albumin for Immune Stimulation in Cancer Treatment.

To efficiently deliver CpG oligodeoxynucleotides (ODNs) to macrophages for the reversal of cancer-induced immunosuppression, nanoparticles ODN@MCBSA with mannosylated cationic albumin (MCBSA) as a macrophage targeting vector were constructed. Compared with ODN@CBSA with cationic albumin (CBSA) as a vector, ODN@MCBSA exhibited significantly improved cellular uptake mediated by mannose moieties, resulting in significantly enhanced secretion of proflammatory cytokines including IL-12, IL-6, TNF-α, and iNOS. The modulation of macrophages toward the favorable M1 phenotype was confirmed by the upregulated CD80 expression after being treated by ODN delivery systems. In addition to immune cells, the effects of the ODN delivery system on cancerous HeLa cells were also investigated. The results showed that ODN@MCBSA did not affect the overall tumor cell viability. However, enhanced NF-κB, p-Akt, PIK3R3, Fas, and FasL, as well as upregulated caspases were observed in tumor cells, implying the pleiotropic effects on tumor cells. Our study provides a more in-depth understanding on the immunotherapeutic effects of CpG ODNs and highlights the importance of macrophage targeting delivery to minimize the effects on tumor cells. These results indicate that MCBSA could serve as a promising delivery vector of CpG ODNs to macrophages for cancer immunotherapy.

In-situ forming thermosensitive hydroxypropyl chitin-based hydrogel crosslinked by Diels-Alder reaction for three dimensional cell culture.

Injectable thermosensitive hydrogels crosslinked physically have been extensively studied as scaffolds in biomedical field, however, their low gel stability with weak strength limits their potential applications. Here, a novel thermosensitive furyl-modified hydroxypropyl chitin polymer was synthesized homogeneously in aqueous solution for developing injectable and dually crosslinked degradable hydrogel by integration of Diels-Alder click reaction using crosslinker maleimide-terminated PEG under physiological conditions. The dually crosslinked chitin-modified hydrogel showed much higher mechanical strength and slower biodegradation rate in contrast with the solely physically crosslinked thermosensitive hydroxypropyl chitin hydrogel. Cells encapsulated in the hydrogel displayed sustainable proliferation and good ability of self-assembling to form multicellular spheroids. In vivo investigation of the thermosensitive chitin-based dually crosslinked hydrogel showed favorable injectability, in-situ thermogelation and good biocompatibility. Thus the injectable, biodegradable and biocompatible dually crosslinked chitin-based hydrogel holds great potential for being applied in three dimensional cell culture and tissue repair.

Efficient Co-delivery of Doxorubicin and Methotrexate by pH-Sensitive Dual-Functional Nanomicelles for Enhanced Synergistic Antitumor Efficacy.

Combination therapy by co-delivering multiple drugs using a single delivery carrier is a promising strategy to achieve a synergistic antitumor effect. In this study, a novel dual-functional block copolymer mPEG-b-poly(TAC-co-ATMC-g-S(CH2)10COOH) was designed and synthesized for co-delivering two kinds of anticancer drugs, methotrexate (MTX) and doxorubicin (DOX). This biodegradable amphiphilic copolymer could spontaneously self-assemble into electronegative nanomicelles with higher micelle stability and lower hemolysis ratio. Besides hydrophobic interactions, electrostatic interactions between the carboxyl groups of 5-allyloxy-1,3-dioxan-2-one (ATMC) with amine groups of DOX, as well as complementary multiple hydrogen-bonding interactions between thymine groups of thymine-functional six-membered cyclic carbonate (TAC) and 2,6-diaminopyridine (DAP) groups of MTX, could contribute to co-delivering DOX/MTX simultaneously with high-efficiency loading without interference with each other. For comparison, DOX alone and MTX alone were also encapsulated into mPEG-b-poly(TAC-co-ATMC-g-S(CH2)10COOH) nanomicelles. All drug-loaded nanomicelles exhibited sustained release properties with a pH sensitivity. Confocal laser scanning microscopy revealed an efficient cell uptake of DOX and MTX delivered by mPEG-b-poly(TAC-co-ATMC-g-S(CH2)10COOH) nanomicelles, while DOX mainly accumulated in nuclei and MTX in cytoplasm after 8 h of incubation. MTT assay further demonstrated an enhanced synergistic antitumor efficacy of DOX/MTX co-loaded nanomicelles. Therefore, DOX/MTX co-loaded mPEG-b-poly(TAC-co-ATMC-g-S(CH2)10COOH) nanomicelles might have attractive potentials in clinical implications for efficient combination chemotherapy.

Multifunctional Vector for Delivery of Genome Editing Plasmid Targeting ß-Catenin to Remodulate Cancer Cell Properties.

Accurate and efficient delivery of genome editing plasmids to targeted cells is of critical importance in genome editing. Herein, we prepared a multifunctional delivery vector with a combination of ligand-mediated selectivity and peptide-mediated transmembrane function to effectively deliver plasmids to targeted cancerous cells. In the delivery system, the clustered regularly interspaced short palindromic repeat-associated Cas9 nuclease (CRISPR-Cas9) plasmid is combined with protamine with membrane and nuclear translocating activities and co-precipitated with CaCO3, which is further decorated by AS1411-functionalized carboxymethyl chitosan and cell penetrating peptide (TAT)-functionalized carboxymethyl chitosan. The AS1411-mediated tumor cell/nuclear targeting and TAT-induced enhanced endocytosis result in obviously increased cellular uptake and nuclear transport. As a result, the CRISPR-Cas9 plasmid can be efficiently delivered to cancer cell nuclei to mediate genome editing, resulting in an efficacious knockout of CTNNB1 gene encoding ß-catenin. More importantly, downregulation of ß-catenin could effectively prevent its enrichment in nuclei and then significantly downregulate the expression of proteins, such as vimentin, Snail, MMP-2, MMP-9, CD44, Nanog, and Oct4 to prevent tumor progression and metastasis. The edited cancerous cells exhibit favorable remodulated properties including inhibited growth, suppressed migration and invasion, and reduced cancer stemness.

An injectable enzymatically crosslinked tyramine-modified carboxymethyl chitin hydrogel for biomedical applications.

The in-situ forming injectable hydrogels have received much attention as scaffolds in the biomedical field, providing a minimally invasive surgical procedure to fill the damaged area. In the present work, carboxymethyl chitin (CMCH) synthesized homogenously was further functionalized with tyramine, resulted in a new injectable enzymatically crosslinked in-situ forming hydrogel under physiological conditions. This new tyramine-modified carboxymethyl chitin (CMCH-Tyr) hydrogel showed much better mechanical properties than those of the thermosensitive in-situ forming physical-crosslinking CMCH hydrogel. The CMCH-Tyr hydrogels remained stable under physiological conditions and could be degraded by lysozyme. The gelation time, strength and biodegradation rate of the CMCH-Tyr hydrogels can be adjusted by varying the concentrations of the horseradish peroxidase and H2O2 in the certain range. In vitro cytotoxicity assays and in vivo in-situ injection study showed non-toxicity, favorable gel formation, and good tissue biocompatibility of the enzyme-catalyzed CMCH-Tyr hydrogel. Thus, the biodegradable and biocompatible CMCH-Tyr hydrogels may hold great potential for three dimensional cell culture and tissue engineering.

Reversal of tumor malignization and modulation of cell behaviors through genome editing mediated by a multi-functional nanovector.

To effectively reverse tumor malignization by genome editing, a multi-functional self-assembled nanovector for the delivery of a genome editing plasmid specifically to tumor cells was developed. The nanovector core consisting of protamine and calcium carbonate entrapping the CRISPR-Cas9 plasmid is decorated by aptamer incorporated heparin. Owing to a high affinity between a MUC1 specific aptamer and mucin 1 (MUC1) overexpressed in tumor cells as well as the interaction between AS1411 and nucleolin on the tumor cell surface and cell nuclei, the nanovector can target the nuclei of tumorous cells for the knockout of focal adhesion kinase (FAK). Notably, the genome editing mediated by our delivery systems can effectively modulate cell behaviors and thus reverse tumor malignization. Up-regulated p53, p16, p21, E-cadherin, CD80, MICA, MICB and Fas, together with down-regulated MMP-9, vimentin, VEGF, TGF-ß, CD47 and CD133 in genome edited cells indicate that the genome editing system can inhibit cancerous cell growth, prevent tumor invasion and metastasis, reverse tumor-induced immune suppression, and inhibit cancer stemness. More importantly, the edited cells can maintain the modulated cellular function after succeeding subcultures.

Fluorinated polymeric micelles to overcome hypoxia and enhance photodynamic cancer therapy.

Photodynamic therapy (PDT) as an alternative choice of cancer treatment method has attracted increasing attention in the past few decades. A sufficient amount of oxygen is essential for the production of singlet oxygen (1O2) in successful PDT; however, hypoxia is a typical hallmark of cancer, which is one of the most important limitation factors of PDT. To overcome the hypoxic tumour microenvironment and achieve highly efficient photodynamic cancer therapy, herein, a photosensitizer Ce6-loaded fluorinated polymeric micelle (Ce6-PFOC-PEI-M) was constructed via the self-assembly of an amphiphilic polymer prepared from perfluorooctanoic acid and branched polyethyleneimine (10 kDa). The introduction of perfluoroalkyl groups in the polymeric micelle Ce6-PFOC-PEI-M retained the oxygen-carrying capacity similar to perfluorocarbon, increased the oxygen level and overcame the hypoxia in C6 glioma cells under oxygen-deficient conditions. As a control, Ce6-OC-PEI-M without a perfluoroalkyl group could not increase the oxygen level in C6 glioma cells under the same conditions. With laser irradiation, Ce6-PFOC-PEI-M generated much more reactive oxygen species (ROS) in C6 glioma cells than Ce6-OC-PEI-M, leading to a higher phototoxicity in vitro and photodynamic tumour growth inhibition in vivo than Ce6-OC-PEI-M. Furthermore, there were no differences in the contents of Ce6 in tumour tissue between Ce6-PFOC-PEI-M and Ce6-OC-PEI-M. The higher efficacy of Ce6-PFOC-PEI-M in PDT is ascribed to its oxygen-carrying ability rather than higher content of Ce6 in the tumour. The presented fluorinated polymeric micelle could provide a new platform in the delivery of various photosensitizers and has great potential to improve the efficacy of PDT cancer therapy.

Tumor targeted genome editing mediated by a multi-functional gene vector for regulating cell behaviors.

For effective regulation of cell behaviors and prevention of tumor development by genome editing, we constructed multi-functional self-assembled nanoparticles based on natural polymers to deliver CRISPR-Cas9 plasmid to tumorous cells. The CRISPR based gene editing plasmid to knockout CDK11 gene was complexed with protamine sulfate, and then the complex was decorated by a multi-functional outer layer composed of an endosomolytic peptide (KALA) and aptamer AS1411 incorporated carboxymethyl chitosan. The resultant multi-functional nanoparticles, which exhibit significantly enhanced delivery efficiency, can specifically deliver the plasmid into tumor cell nuclei owing to the favorable effects of KALA in cellular uptake and endosomal escape, together with the cancer cell and cell nucleus targeting capability of AS1411 ligands. The genome editing mediated by the nanoparticles leads to a dramatic decrease (>75%) in CDK11 expression, which results in further modulation of cancer cells with significant down-regulation of the proteins (MMP-9 and VEGF) involved in tumor development and metastasis as well as up-regulation of the tumor suppressor protein p53. More importantly, the detection of immune-related proteins after genome editing shows that the significantly enhanced Fas, CD80, MICA, MICB, and HLA-1 expression and decreased CD47 and MUC1 expression, indicating the genome editing is favorable for reversal of tumor-induced immunosuppression and prevention of tumor development.

A multi-functional macrophage and tumor targeting gene delivery system for the regulation of macrophage polarity and reversal of cancer immunoresistance.

To achieve effective tumor eradication using anti-tumor immunotherapies, a fusion peptide functionalized gene delivery system for macrophage and tumor targeting delivery of the plasmid DNA encoding the IL-12 gene (pDNA IL-12) was prepared for macrophage re-polarization as well as reversal of cancer immunosuppression. A fusion peptide containing the tuftsin sequence that can interact with Fc receptors and neuropilin-1, and hyaluronic acid (HA) that can interact with CD44 were introduced into the delivery system by self-assembly to form peptide/hyaluronic acid/protamine/CaCO3/DNA nanoparticles (PHNP) with both macrophage targeting and tumor targeting capabilities. PHNP provides an efficient immunoregulation on J774A.1 cells to shift the anti-inflammatory M2 phenotype to the anti-tumor M1 phenotype with enhanced secretion of pro-inflammatory cytokines and increased expression of M1 markers. Owing to the improved delivery efficiency caused by the fusion peptide and HA, the transfection mediated by multi-functional PHNP can up-regulate IL-12 as well as down-regulate IL-10 and IL-4 more effectively as compared with the nanoparticles without HA and/or peptide decoration. More importantly, the gene delivery system can also deliver pDNA IL-12 to targeted cancerous HeLa cells to realize the secretion of IL-12. PHNP not only enables tumorous cells to produce pDNA IL-12, but also down-regulates CD47 and up-regulate CD80 and HLA-1 in the malignant cells, indicating that the gene delivery system can effectively reverse tumor induced immunosuppression.

Aptamer-functionalized albumin-based nanoparticles for targeted drug delivery.

Proteins have been extensively explored as versatile nanocarriers for drug delivery due to their complete biocompatibility, ease of surface modification, and lack of toxicity and immunogenicity. In this study, a facile strategy was used to construct aptamer-functionalized albumin-based nanoparticles for effective drug delivery and targeted cancer therapy. A hydrophobic drug, doxorubicin (DOX) was employed to trigger the self-assembly of bovine serum albumin (BSA) to from stable nanoparticles via hydrophobic interaction, and then a tumor targeting aptamer AS1411 was incorporated to the surface of DOX loaded BSA. Due to the specific recognition between AS1411 and its receptor over-expressed on tumor cells, the aptamer-modified nanoparticles show higher cellular uptake and stronger cell inhibitory efficacy against cancerous MCF-7 cells as compared with the nanoparticles without aptamer modification. In addition, DOX loaded aptamer-functionalized nanoparticles can induce more significant down-regulation of Bcl-2 and PCNA as well as up-regulation of pRB, PARP and Bax in MCF-7 cells compared with unmodified nanoparticles, indicating the aptamer modification can induce cell apoptosis more effectively. Besides, aptamer-modified nanoparticles exhibit a significantly improved capability in up-regulating p16, p21 and E-cadherin, and down-regulating EpCAM, vimentin, Snail, MMP-9, CD44 and CD133, implying the favorable effects of drug delivery on the prevention of tumor progression and metastasis.

A Dual-Targeting Delivery System for Effective Genome Editing and In Situ Detecting Related Protein Expression in Edited Cells.

One of critical steps in genome editing by CRISPR-Cas9 is to deliver the CRISPR-Cas9 system into targeted cells. In this study, we developed a dual-targeting delivery system based on polymer/inorganic hybrid nanoparticles to realize highly efficient genome editing in targeted tumor cells as well as in situ detection on the related protein expression in edited cells. The CRISPR-Cas9 plasmid for CDK11 knockout was encapsulated in the core of the delivery system composed of protamine sulfate, calcium carbonate, and calcium phosphate by coprecipitation, and functional derivatives of carboxymethyl chitosan (biotinylated carboxymethyl chitosan with biotin ligands and aptamer-incorporated carboxymethyl chitosan with AS1411 ligands) were decorated on the nanovector surface by electrostatic interactions to form the dual-targeting delivery system. On the basis of the tumor cell targeting capability of biotin and AS1411 ligands as well as the nuclear targeting of AS1411, the dual-targeting system can deliver the CRISPR-Cas9 plasmid into the nuclei of tumor cells to realize highly efficient genome editing, resulting in a dramatic decrease (>90%) in CDK11 protein together with the significant downregulation of other proteins involved in tumor development, including an ∼90% decrease in MMP-9, >40% decrease in VEGF, and ∼70% decrease in survivin. Using the same vector, molecular beacons can be easily delivered to edited cell nuclei to in situ detect the mRNA level of related proteins (p53 and survivin as typical examples) and mRNA distribution in subcellular organelles. Our strategy can realize effective genome editing and in situ detection on related protein expression simultaneously.

Thermosensitive and photocrosslinkable hydroxypropyl chitin-based hydrogels for biomedical applications.

In situ forming injectable hydrogels based on thermosensitive polymers are being investigated for tissue engineering applications. However, the major limitations of this kind of hydrogels are low gel stability and weak mechanical properties under physiological conditions. Here, thermosensitive hydroxypropyl chitin (HPCH) was synthesized homogenously and subsequently functionalized with photocrosslinkable methacrylate groups via glycidyl methacrylate to generate glycidyl methacrylate-modified HPCH (GM-HPCH). The obtained new GM-HPCH polymers exhibited similar reversible thermosensitive sol-gel transition behaviors at a low concentration (2 wt% in PBS). The physical thermogelation GM-HPCH hydrogels were able to be photocrosslinked by UV irradiation under physiological conditions to form enhanced stable and mechanically strong hydrogels. The mechanical property, swelling and degradation behavior of the hydrogels could be tuned by controlling the degree of substitution of methacrylate groups and UV exposure time. Cytotoxicity test displayed that the photocrosslinked thermogels were non-cytotoxic. The photocrosslinkable GM-HPCH thermogels hold great potential for biomedical applications.

Dual Drug Delivery System Based on Biodegradable Organosilica Core-Shell Architectures.

To overcome drug resistance, efficient cancer therapeutic strategies using a combination of small-molecule drugs and macromolecule drugs is highly desired. However, because of their significant differences in molecular weight and size, it is difficult to load them simultaneously in one vector and to release them individually. Here, a biodegradable organosilica-based core-shell-structured nanocapsule was designed and used as a dual stimuli-responsive drug vector to solve this problem. Biodegradable organosilica shell coated outside the macromolecule model drug "core" would be disrupted by high glutathione (GSH) levels inside tumor cells, resulting in the escape of the entrapped drugs. Small-molecule drugs capping on the surface of the organosilica shell via pH-responsive imine bonds can be cut and released in the acidic lysosomal environment. Transmission electron microscopy has shown that the framework of the organosilica shell was dissolved and degraded after 8 h incubation with 5 mM GSH. Confocal imaging confirmed that small-molecule and macromolecular drugs were individually released from the nanoparticles because of the pH or redox-triggered degradation under the tumor microenvironment and thus led to the strong fluorescence recovery in the cytoplasm. As expected, these biodegradable organosilica nanoparticles could not release drugs into normal cells but could specifically release them into tumor cells owing to their tumor-triggered targeting capability. This system will serve as an efficient shuttle for multidrug delivery and also provide a potential strategy to overcome drug resistance.

A bioreducible supramolecular nanoparticle gene delivery system based on cyclodextrin-conjugated polyaspartamide and adamantyl-terminated polyethylenimine.

This article describes a novel reduction degradable supramolecular nanoparticle gene delivery system via host-guest interaction based on cyclodextrin-conjugated polyaspartamide with disulfide linkage (Pasp-SS-CD) and adamantyl-terminated polyethylenimine (Ad4-PEI). The reduction responsiveness of Pasp-SS-CD and the Pasp-SS-CD/Ad4-PEI/pDNA supramolecular nanoparticles (SNPs) in the presence of dl-dithiothreitol (DTT) was confirmed by SEC-MALLS and DLS analysis, respectively. Compared with the Ad4-PEI/pDNA polyplexes, the bioreducible supramolecular polycation/pDNA polyplexes exhibited smaller particle size, slightly higher zeta potential, lower cytotoxicity and hemolysis ratio, improved cellular internalization and higher gene transfection efficiency. It was found that introducing Pasp-SS-CD to assemble Ad4-PEI could substantially enhance the tolerance of protein adsorption and maintain the gene transfer capacity of polycationic carriers, which might be beneficial for in vivo use. In addition, the cellular uptake pathway of the supramolecular polycation/pDNA polyplexes was investigated using different uptake inhibitors. The present study demonstrates that the proper assembly of cyclodextrin-conjugated polyaspartamide and adamantyl-terminated polyethylenimine is an effective strategy for the production of a new gene delivery system.

Folate-conjugated amphiphilic block copolymer micelle for targeted and redox-responsive delivery of doxorubicin.

In this paper, novel folate-conjugated and redox-responsive crosslinked block copolymer was successfully synthesized for targeted and controlled release of doxorubicin (DOX) to cancer cells. Folate-conjugated poly(ethylene glycol)-b-copolycarbonates (FA-PEG-b-P(MAC-co-DTC)) and methoxy poly(ethylene glycol)-b-copolycarbonates (mPEG-b-P(MAC-co-DTC)) were firstly synthesized by enzymatic method. FA-PEG/mPEG-b-P(MAC-co-DTC)-SS was then obtained by further crosslinking reaction with cystamine. Non-conjugated crosslinked copolymer mPEG-b-P(MAC-co-DTC)-SS- and non-conjugated uncrosslinked copolymer mPEG-b-P(MAC-co-DTC) were also synthesized for comparison. All the amphiphlic copolymers could self-assemble to form nano-sized micelles which dispersed in spherical shape before and after DOX loading. The core crosslinking structure of FA-PEG/mPEG-b-P(MAC-co-DTC)-SS could improve the micellar stability and drug loading capacity, while in vitro release studies also showed more sustained drug release behavior which could be accelerated in reductive condition. Moreover, confocal laser scanning microscopy indicated that the conjugation of FA could enhance the cellular uptake efficiency obviously via FA-receptor-mediated endocytosis, and MTT assays demonstrated highly potent cytotoxic activity of FA-PEG/mPEG-b-P(MAC-co-DTC)-SS.

A Dual Macrophage Targeting Nanovector for Delivery of Oligodeoxynucleotides To Overcome Cancer-Associated Immunosuppression.

To overcome cancer-associated immunosuppression, we prepared a dual-targeting vector to deliver CpG oligodeoxynucleotides (ODN) to macrophages. The dual-targeting system composed of mannosylated carboxymethyl chitosan (MCMC)/hyaluronan (HA) for macrophage targeting and protamine sulfate for ODN complexation was prepared by self-assembly. The effects of ODN delivery on immune cells was studied in J774A.1 cells. Due to the enhanced delivery efficiency, the dual-targeting delivery system exhibits a higher immune stimulatory activity compared with the monotargeting delivery system containing either MCMC or HA, resulting in a dramatically enhanced secretion of proinflammatory cytokines and a successful shift to activated macrophages (M1). Besides macrophages, the influence of the delivery system on tumor cells (MCF-7) was also investigated. In MCF-7 cells, the increased expressions of nuclear transcription factor-κB (NF-κB), PIK3R3, and phosphorylated protein kinase B (p-Akt) caused by activated NF-κB and phosphoinositide 3-kinase/Akt signalings were observed. Nevertheless, upregulated Fas as well as Fas ligand (FasL) may induce Fas/FasL-mediated apoptosis, which results in the increased expressions of caspases in tumor cells.

Redox-triggered activation of nanocarriers for mitochondria-targeting cancer chemotherapy.

The importance of mitochondrial delivery of an anticancer drug to cancer cells has been recognized to improve therapeutic efficacy. The introduction of lipophilic cations, such as triphenylphosphonium (TPP), onto the surface of nanocarriers was utilized to target mitochondria via strong electrostatic interactions between positively charged TPP and the negatively charged mitochondrial membrane. However, the highly positive charge nature of TPP leads to rapid clearance from the blood, decrease of circulation lifetime, and nonspecific targeting of mitochondria of cells. Here, we report a strategy for improving the anticancer efficacy of paclitaxel via redox triggered intracellular activation of mitochondria-targeting. The lipid-polymer hybrid nanoparticles (LPNPs) are composed of poly(d,l-lactide-co-glycolide) (PLGA), a TPP-containing amphiphilic polymer (C18-PEG2000-TPP) and a reduction-responsive amphiphilic polymer (DLPE-S-S-mPEG4000). The charges of TPP in LPNPs were almost completely shielded by surface coating of a PEG4000 layer, ensuring high tumor accumulation. After uptake by cancer cells, the surface charges of LPNPs were recovered due to the detachment of PEG4000 under intracellular reductive conditions, resulting in rapid and precise localization in mitochondria. This kind of simple, easy and practicable mitochondria-targeting nanoplatform showed high anticancer activity, and the activatable strategy is valuable for developing a variety of nanocarriers for application in the delivery of other drugs.

MRI-guided targeting delivery of doxorubicin with reduction-responsive lipid-polymer hybrid nanoparticles.

In recent years, there has been increasing interest in developing a multifunctional nanoscale platform for cancer monitoring and chemotherapy. However, there is still a big challenge for current clinic contrast agents to improve their poor tumor selectivity and response. Herein, we report a new kind of Gd complex and folate-coated redox-sensitive lipid-polymer hybrid nanoparticle (Gd-FLPNP) for tumor-targeted magnetic resonance imaging and therapy. Gd-FLPNPs can simultaneously accomplish diagnostic imaging, and specific targeting and controlled release of doxorubicin (DOX). They exhibit good monodispersity, excellent size stability, and a well-defined core-shell structure. Paramagnetic nanoparticles based on gadolinium-diethylenetriaminepentaacetic acid-bis-cetylamine have paramagnetic properties with an approximately two-fold enhancement in the longitudinal relaxivity compared to clinical used Magnevist. For targeted and reduction-sensitive drug delivery, Gd-FLPNPs released DOX faster and enhanced cell uptake in vitro, and exhibited better antitumor effect both in vitro and in vivo.