Nanocarrier Complexes Research Articles

Formulation and characterization of cisplatin-loaded hydroxyl functionalized single-walled carbon nanotubes for targeting gastric cancer stem cells

Chemotherapy is the most commonly used therapeutic method for treating many malignancies including gastric cancer. Due to their non-specific and non-targeted drug delivery, it causes resistance leading to cancer progression, relapse, and metastasis of cancer. To overcome this problem we carried out a study aimed to develop a new cisplatin (Cisp) loaded hydroxyl functionalized single-walled carbon nanotube (OH-SWCNT) nanocarrier system to selectively eliminate gastric cancer stem cells. To our understanding, this is the first study of the non-covalent interaction of cisplatin loaded on the surface of hydroxyl-functionalized single-walled carbon nanotubes by ultrasonication. The physical and morphological characterization was carried out by UV–Vis, FTIR spectroscopy, and TEM. A sustained and controlled release of cisp from OH-SWCNT at all three pHs 3.5, 5.5, and 7.4 was observed. Gastric cancer stem cells were isolated from primary cells and were identified by using CD133+ and CD44+ specific markers. Cisplatin-loaded OH-SWCNT nanocarrier was capable of limiting the self-renewal capacity of both CD133+ and CD44+ populations and also decreasing the number of tumorspheres in gastric CSCs. The cell viability percent of AGS cells was 20% at 250 μg/ml concentration. The IC50 value was less than 50% mol/L at both 200 μg/ml and 250 μg/ml of cisplatin-loaded OH-SWCNT. Our findings suggest that cisplatin-loaded OH-SWCNT nanocarrier complexes could target gastric CSCs and also could provide a potential strategy for selectively targeting and efficiently eliminating gastric CSCs. This could be a promising approach to prevent gastric cancer recurrence and metastasis and also improve gastric cancer therapy.

Intranasal Administration of a TRAIL Neutralizing Monoclonal Antibody Adsorbed in PLGA Nanoparticles and NLC Nanosystems: An In Vivo Study on a Mouse Model of Alzheimer's Disease.

Alzheimer’s disease (AD) is a neurodegenerative disorder that progressively compromises cognitive functions. Tumor necrosis factor (TNF)-Related Apoptosis Inducing Ligand (TRAIL), a proinflammatory cytokine belonging to the TNF superfamily, appears to be a key player in the inflammatory/immune orchestra of the AD brain. Despite the ability of an anti-TRAIL monoclonal antibody to reach the brain producing beneficial effects in AD mice, we attempted to develop such a TRAIL-neutralizing monoclonal antibody adsorbed on lipid and polymeric nanocarriers, for intranasal administration, in a valid approach to overcome issues related to both high dose and drug transport across the blood–brain barrier. The two types of nanomedicines produced showed physico-chemical characteristics appropriate for intranasal administration. As confirmed by enzyme-linked immunosorbent assay (ELISA), both nanomedicines were able to form a complex with the antibody with an encapsulation efficiency of ≈99%. After testing in vitro the immunoneutralizing properties of the nanomedicines, the latter were intranasally administered in AD mice. The antibody–nanocarrier complexes were detectable in the brain in substantial amounts at concentrations significantly higher compared to the free form of the anti-TRAIL antibody. These data support the use of nanomedicine as an optimal method for the delivery of the TRAIL neutralizing antibody to the brain through the nose-to-brain route, aiming to improve the biological attributes of anti-TRAIL-based therapy for AD treatment.

Development of a magnetic MoS2 system camouflaged by lipid for chemo/phototherapy of cancer

Untargeted release of traditional chemotherapeutic drugs can damage normal tissues in the body and cause serious side effects for patients. Therefore, the research of targeted drug delivery system based on nanomaterials has become a hot topic in the field of cancer therapy. Magnetic molybdenum disulfide (mMoS2) was modified by liposomes with a cell membrane-like structure to prepare nanocarrier complex (mMoS2-Lipid) with high biocompatibility and stability. Then, combined photo-chemotherapeutic therapy was realized both in vitro and in vivo by its ultra-high photothermal conversion efficiency and excellent drug loading profile of mMoS2-Lipid. The characterization showed that the lamellar magnetic molybdenum disulfide modified by liposomes was not easy to aggregate in physiological solution, and had a lower non-specific protein adsorption rate, which was beneficial for biomedical application. In vitro cell experiments exhibited a successful cellular uptake profile of MCF-7 cells with no significant cytotoxicity, while a concentration dependent cytotoxicity for both chemotherapy alone and photo-chemotherapy combined therapy. Compared with the unmodified mMoS2, mMoS2-Lipid injected into mice through tail vein can accumulate more in the tumor site, and in vivo anti-tumor studies have shown that the synergistic treatment of the mMoS2-Lipid has an obvious inhibitory effect on the tumor with less toxic and side effects on mice. In conclusion, mMoS2-Lipid treatment system provides a safe, rapid and effective choice for the treatment of breast cancer in the future.

Modulation of CD36-mediated lipid accumulation and senescence by vitamin E analogs in monocytes and macrophages.

The CD36/FAT scavenger receptor/fatty acids transporter regulates cellular lipid accumulation important for inflammation, atherosclerosis, lipotoxicity, and initiation of cellular senescence. Here we compared the regulatory effects of the vitamin E analogs alpha-tocopherol (αT), alpha-tocopheryl phosphate (αTP), and αTP/βCD (a nanocarrier complex between αTP and β-cyclodextrin [βCD]) and investigated their regulatory effects on lipid accumulation, phagocytosis, and senescence in THP-1 monocytes and macrophages. Both, αTP and αTP/βCD inhibited CD36 surface exposition stronger than αT leading to more pronounced CD36-mediated events such as inhibition of DiI-labeled oxLDL uptake, phagocytosis of fluorescent Staphylococcus aureus bioparticles, and cell proliferation. When compared to βCD, the complex of αTP/βCD extracted cholesterol from cellular membranes with higher efficiency and was associated with the delivery of αTP to the cells. Interestingly, both, αTP and more so αTP/βCD inhibited lysosomal senescence-associated beta-galactosidase (SA-β-gal) activity and increased lysosomal pH, suggesting CD36-mediated uptake into the endo-lysosomal phagocytic compartment. Accordingly, the observed pH increase was more pronounced with αTP/βCD in macrophages whereas no significant increase occurred with αT, alpha-tocopheryl acetate (αTA) or βCD. In contrast to αT and αTA, the αTP molecule is di-anionic at neutral pH, but upon moving into the acidic endo-lysosomal compartment becomes protonated and thus is acting as a base. Moreover, it is expected to be retained in lysosomes since it still carries one negative charge, similar to lysosomotropic drugs. Thus, treatment with αTP or αTP/βCD and/or inhibition of conversion of αTP to αT as it occurs in aged cells may counteract CD36-mediated overlapping inflammatory, senescent, and atherosclerotic events.

Novel insights into the roles and therapeutic implications of MUC1 oncoprotein via regulating proteins and non-coding RNAs in cancer.

Mucin 1 (MUC1) is a heterodimeric transmembrane glycoprotein that protects epithelial cells in mammals. The transmembrane C-terminal subunit (MUC1-C) plays a crucial role in oncogenesis. As an oncoprotein, MUC1-C regulates a number of proteins that are associated with tumorigenesis by interacting with oncoproteins, transcription factors, coactivators, etc., inducing proliferation, epithelial-mesenchymal transition (EMT), invasion, stemness, immune evasion, and drug resistance. Moreover, MUC1-C modulates the expression of non-coding RNAs (ncRNAs), which further regulate carcinogenesis by directly binding to specific proteins. ncRNAs can also affect MUC1 protein expression by targeting the MUC1 mRNA 3′ untranslated region (UTR). A series of ncRNAs can modulate cancer development by regulating MUC1-C. This review focuses on the interaction of MUC1-C with proteins and ncRNAs in cancer progression. We also summarize the recent advances in immunotherapy with a focus on therapeutic approaches based on MUC1-C and nanocarrier complexes for cancer treatment.

Complementary Nucleobase Interactions Drive Co-Assembly of Drugs and Nanocarriers for Selective Cancer Chemotherapy.

A new concept in cooperative adenine–uracil (A–U) hydrogen bonding interactions between anticancer drugs and nanocarrier complexes was successfully demonstrated by invoking the co-assembly of water soluble, uracil end-capped polyethylene glycol polymer (BU-PEG) upon association with the hydrophobic drug adenine-modified rhodamine (A-R6G). This concept holds promise as a smart and versatile drug delivery system for the achievement of targeted, more efficient cancer chemotherapy. Due to A–U base pairing between BU-PEG and A-R6G, BU-PEG has high tendency to interact with A-R6G, which leads to the formation of self-assembled A-R6G/BU-PEG nanogels in aqueous solution. The resulting nanogels exhibit a number of unique physical properties, including extremely high A-R6G-loading capacity, well-controlled, pH-triggered A-R6G release behavior, and excellent structural stability in biological media. Importantly, a series of in vitro cellular experiments clearly demonstrated that A-R6G/BU-PEG nanogels improved the selective uptake of A-R6G by cancer cells via endocytosis and promoted the intracellular release of A-R6G to subsequently induce apoptotic cell death, while control rhodamine/BU-PEG nanogels did not exert selective toxicity in cancer or normal cell lines. Overall, these results indicate that cooperative A–U base pairing within nanogels is a critical factor that improves selective drug uptake and effectively promotes apoptotic programmed cell death in cancer cells.

Tumor-derived exosomes encapsulating miR-34a promote apoptosis and inhibit migration and tumor progression of colorectal cancer cells under in vitro condition.

MicroRNA (miR)-34a, as a master tumor suppressor in colorectal cancer (CRC), could regulate multiple genes participating in tumor proliferation, invasion, immune evasion, and inflammation-induced progression. Exosomes, as novel nano-carriers, were found to be capable of shuttling crucial mediators to various cells. Since the conventional CRC therapeutics currently are a matter of debate, implication of microRNAs in malignancy remedies have been addressed illustrating promising outlooks. In this study, we aimed to investigate the delivery of miR-34a to CRC cell line CT-26 by encapsulating into tumor-derived exosomes (TEXs), in order to evaluate the anti-proliferative and progressive effects of the novel nano-carrier complex under in vitro condition. Exosomes were purified from the starved CT-26 cells and then enriched by miR-34a using the calcium chloride (Cacl2) modified solution. Following the detection of miR-34a expression in the enriched TEXs, the viability of CT-26 cells treated by multiplicity concentrations of either TEXs or TEX-miR-34a was examined. Moreover, the apoptosis rate of the cells was evaluated, and the migration of CT-26 cells subjected to both TEX-miR-34a and TEX was also measured. Thereafter, the expressions of miR-34a target genes, as IL-6R, STAT3, PD-L1, and VEGF-A, which play roles in tumor progression, were determined in the treated CT-26 cells. The viability of CT-26 cells was harnessed following the treatment with TEX-miR-34a and the apoptosis levels of the cells were also observed to be enhanced dose-dependently. TEX-miR-34a was able to diminish the migration rate of the TEX-miR-34a treated cells and the expressions of IL-6R, STAT3, PD-L1, and VEGF-A were significantly restricted. Moreover, TEXs alone increased the apoptosis rate of tumor cells and repressed the proliferation and migration of these cells which were boosted by enrichment of TEXs with miR-34a. Exosomes isolated from the starved CT-26 cells were found to have a potential to deliver miR-34a into tumor cells properly with high functionality maintenance for miR-34a in case of regulating genes related to tumor progression and TEXs which showed no positive effect favoring cancer cells, presumably act as a favorable adjuvant in the CRC therapy.

Moxifloxacin and Sulfamethoxazole-Based Nanocarriers Exhibit Potent Antibacterial Activities.

Antibiotic resistance is a major concern given the rapid emergence of multiple-drug-resistant bacteria compared to the discovery of novel antibacterials. An alternative strategy is enhancing the existing available drugs. Nanomedicine has emerged as an exciting area of research, showing promise in the enhanced development of existing antimicrobials. Herein, we synthesized nanocarriers and loaded these with available clinically approved drugs, namely Moxifloxacin and Sulfamethoxazole. Bactericidal activity against Gram-negative (Serratia marcescens, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Salmonella enterica) and Gram-positive (methicillin-resistant Staphylococcus aureus, Streptococcus pneumoniae, and Bacillus cereus) bacteria was investigated. To characterize the nanocarriers and their drug-loaded forms, Fourier-transform infrared spectroscopy, dynamic light scattering, and atomic force microscopy were utilized. Antibacterial assays and hemolysis assays were carried out. Moreover, lactate dehydrogenase assays were performed to determine cytotoxicity against human cells. The results depicted the successful formation of drug–nanocarrier complexes. The potent antibacterial activities of the drug-loaded nanocarriers were observed and were significantly enhanced in comparison to the drugs alone. Hemolysis and cytotoxicity assays revealed minimal or negligible cytotoxic effects against human red blood cells and human cells. Overall, metronidazole-based nanocarriers loaded with Moxifloxacin and Sulfamethoxazole showed enhanced bactericidal effects against multiple-drug-resistant bacteria compared with drugs alone, without affecting human cells. Our findings show that drug-loaded nanocarriers hold promise as potent chemotherapeutic drugs against multiple-drug-resistant bacteria.

Modulation of CD36‐mediated Lipid Accumulation and Senescence by Vitamin E Analogues in Monocytes and Macrophages

The CD36/FAT scavenger receptor/fatty acids transporter regulates cellular lipid accumulation important for inflammation, atherosclerosis, lipotoxicity and initiation of cellular senescence. During stress-induced premature senescence (SIPS), a number of stimuli (e.g., oxLDL, β-amyloid and 4-hydroxynonenal) may lead to up-regulation of CD36-mediated lipid uptake triggering signaling and the expression of lipid-regulating and inflammatory genes involved in the senescence-associated secretory phenotype (SASP) characterized by secretion of cytokines, chemokines, lipids and proteases. Both, SIPS and SASP may be modulated by vitamin E (alpha-tocopherol, αT), since it inhibits CD36 expression, cell surface exposition and CD36-associated signaling. Here we compared the regulatory effects of αT, αTP (alpha-tocopheryl phosphate, αTP) and αTP/βCD (a nanocarrier complex between αTP and β-cyclodextrin (βCD)) and investigated their regulatory effects on lipid accumulation, phagocytosis and senescence in THP-1 monocytes and macrophages. Both, αTP and αTP/βCD inhibited CD36 surface exposition stronger that αT leading to more pronounced CD36-mediated events such as inhibition of DiI-labelled oxLDL uptake, phagocytosis of fluorescent Staphylococcus aureus bioparticles, and cell proliferation. When compared to βCD, the complex of αTP/βCD extracted cholesterol from cellular membranes with higher efficiency and was associated with delivery of αTP to the cells, thus forming a Dual-Action Lipid-lowering complex (DALC). Interestingly, both, αTP and more so αTP/βCD inhibited lysosomal senescent-associated beta-galactosidase (SA-β-gal) activity and increased lysosomal pH, suggesting CD36-mediated uptake into the endo-lysosomal phagocytic compartment. Accordingly, the observed pH increase was more pronounced with αTP/βCD in macrophages when compared to monocytes, possibly due to their increased ability to phagocytose the αTP/βCD complex, whereas no significant change of pH occurred with αT, alpha-tocopherol acetate (αTA) or βCD. In contrast to αT and αTA, the αTP molecule is di-anionic at neutral pH (calculated pKa1 1.64 and pKa2 6.07), but upon moving into the acidic endo-lysosomal compartment becomes protonated and thus is acting as a base. Moreover, it is expected to be retained in lysosomes since it still carries one negative charge, as it occurs also with lysosomotropic drugs such as chloroquine and hydroxychloroquine. Thus, treatment with αTP or αTP/βCD and/or inhibition of conversion of αTP to αT as it occurs in aged cells may counteract CD36-mediated overlapping inflammatory, senescent, and atherosclerotic events.

Treatment of primary and metastatic breast and pancreatic tumors upon intravenous delivery of a PRDM14-specific chimeric siRNA/nanocarrier complex.

PRDM14 is highly expressed in several cancers but is not detected in normal tissues. It confers cancer stem cell-like properties, including chemoresistance and distant metastasis, to cancer cells. Herein, we aimed to develop a highly effective therapy against advanced stage cancer based on intravenously delivered PRDM14-targeted siRNA. First, we examined PRDM14 expression and gene amplification in breast and pancreatic tumors and cell lines. PRDM14 was expressed in breast cancer, including the triple-negative subtype, and pancreatic cancer. PRDM14 was amplified in 23.8% of patients with PRDM14+ breast cancer. Next, we investigated the inoculated tumor growth and distant metastasis following PRDM14 depletion by administering mice with PRDM14-specific chimeric siRNA combined with a novel branched PEGylated poly-L-ornithine (PLO)-based intravenous drug delivery system, designated PRDM14 unit polyion complex (uPIC) (n = 6/group). Inhibition of PRDM14 expression with PRDM14 uPIC by systemic intravenous injection effectively reduced tumor size and metastasis in vivo, thereby improving survival. Finally, pharmacokinetic/toxicokinetic analyses were performed on PRDM14 uPIC, which was intravenously administered to rats (n = 10-15/group) and cynomolgus monkeys (n = 3-5/group), twice weekly for 4 weeks. This revealed that PRDM14 uPIC was relatively nontoxic and the siRNA exposure in serum was greater than that predicted by the administered dose ratio when delivered as a uPIC. Taken together, our study indicated that PRDM14 uPIC is highly effective in suppressing malignant features of solid cancers and does not cause severe toxicity, making it a promising therapeutic agent for cancer treatment.

DOTA Glycodendrimers as Cu(II) Complexing Agents and Their Dynamic Interaction Characteristics toward Liposomes

Copper (Cu)(II) ions, mainly an excess amount, play a negative role in the course of several diseases, like cancers, neurodegenerative diseases, and the so-called Wilson disease. On the contrary, Cu(II) ions are also capable of improving anticancer drug efficiency. For this reason, it is of great interest to study the interacting ability of Cu(II)–nanodrug and Cu(II)–nanocarrier complexes with cell membranes for their potential use as nanotherapeutics. In this study, the complex interaction between 1,4,7,10-tetraazacyclododecan-N,N′,N′′,N′′′-tetraacetic acid (DOTA)-functionalized poly(propyleneimine) (PPI) glycodendrimers and Cu(II) ions and/or neutral and anionic lipid membrane models using different liposomes is described. These interactions were investigated via dynamic light scattering (DLS), ζ-potential (ZP), electron paramagnetic resonance (EPR), fluorescence anisotropy, and cryogenic transmission electron microscopy (cryo-TEM). Structural and dynamic information about the PPI glycodendrimer and its Cu(II) complexes toward liposomes was obtained via EPR. At the binding site Cu–N2O2 coordination prevails, while at the external interface, this coordination partially weakens due to competitive dendrimer–liposome interactions, with only small liposome structural perturbation. Fluorescence anisotropy was used to evaluate the membrane fluidity of both the hydrophobic and hydrophilic parts of the lipid bilayer, while DLS and ZP allowed us to determine the distribution profile of the nanoparticle (PPI glycodendrimer and liposomes) size and surface charge, respectively. From this multitechnique approach, it is deduced that DOTA-PPI glycodendrimers selectively extract Cu(II) ions from the bioenvironment, while these complexes interact with the liposome surface, preferentially with even more negatively charged liposomes. However, these complexes are not able to cross the cell membrane model and poorly perturb the membrane structure, showing their potential for biomedical use.

Nanocarriers of Fe3O4 as a Novel Method for Delivery of the Antineoplastic Agent Doxorubicin Into HeLa Cells in vitro.

Here we report the synthesis and in vitro characterization of a redox-sensitive, magnetically inducible nanoparticle carrier system based on the doxorubicin (DOX) drug delivery model. Each quantal nanocarrier unit consists of a magnetite Fe3O4 nanoparticle core that is further encapsulated in self-assembled micelles of the redox-responsive polyethylene glycol derivative, DSPE-SS-mPEG. The nanocarrier system was prepared using a combination of ultrasonication and dialysis to produce the microenvironment sensitive delivery system. The final synthesized and DOX-loaded magnetic nanocarriers had an average size of ~150 nm when assembled with a 6.9% DOX payload. The release rate of DOX from these redox-responsive magnetic nanocarriers was shown to be accelerated in vitro when in the presence of glutathione (GSH). Furthermore, we demonstrated that more redox-responsive magnetic nanocarriers could be taken up by HeLa cells when a local magnetic field was applied. Once internalized within a cell, the micelles of the outer nanocarrier complex were broken down in the presence of higher concentrations of GSH, which accelerated the release of DOX. This produces a particle with dual operating characteristics that can be controlled via a specific cellular environment coupled with an exogenously applied signal in the form of a magnetic field triggering release.

Multifunctional silver nanocluster-hybrid oligonucleotide vehicle for cell imaging and microRNA-targeted gene silencing

Novel therapeutics is urgently needed to prevent cancer-related deaths. MicroRNAs that act as tumor suppressors have been recognized as a next-generation tumor therapy, and the restoration of tumor-suppressive microRNAs using microRNA replacements or mimics may be a less toxic, more effective strategy due to fewer off-target effects. Here, we designed the novel multifunctional oligonucleotide nanocarrier complex composed of a tumor-targeting aptamer sequence specific to mucin 1 (MUC1), poly-cytosine region for fluorescent silver nanocluster (AgNC) synthesis, and complimentary sequence for microRNA miR-34a loading. MiR-34a was employed because of its therapeutic effect of inhibiting oncogene expression and inducing apoptosis in carcinomas. By monitoring the intrinsic fluorescence of AgNC, it was clearly shown that the constructed complex (MUC1-AgNCm-miR-34a) enters MCF-7 cells. To evaluate the efficacy of this nanocarrier for microRNA delivery, we investigated the gene and protein expression levels of downstream miR-34a targets (BCL-2, CDK6, and CCND1) by quantitative PCR and western blotting, respectively, and the results indicated their effective inhibition by miR-34a. This novel multifunctional AgNC-based nanocarrier can aid in improving the efficacy of breast cancer theranostics.

Antibody-Conjugated, DNA-Based Nanocarriers Intercalated with Doxorubicin Eliminate Myofibroblasts in Explants of Human Lens Tissue

Posterior capsule opacification (PCO) occurs in some adults and most children following cataract surgery. The fibrotic form of PCO arises, in part, from migratory, contractile myofibroblasts that deform the lens capsule and impair vision. In short-term cultures of human anterior lens tissue, myofibroblasts emerge from Myo/Nog cells that are identified with the G8 monoclonal antibody and by their expression of the MyoD transcription factor and bone morphogenetic protein inhibitor noggin. In this study, we tested the hypothesis that targeted depletion of Myo/Nog cells with the G8 monoclonal antibody (mAb) conjugated to three-dimensional DNA nanocarriers intercalated with doxorubicin (G8:3DNA:Dox) would prevent the accumulation of myofibroblasts in long-term, serum- and growth factor-free cultures of human lens tissue obtained by capsulorhexis. The mAb:nanocarrier complex was internalized into acidic compartments of the cell. G8:3DNA:Dox killed nearly all Myo/Nog cells without affecting the lens epithelial cells. In 30-day cultures, all G8-positive cells expressed noggin, and subpopulations had synthesized MyoD, sarcomeric myosin, and alpha smooth muscle actin (α-SMA). Myo/Nog cells responded to scratching of the lens epithelium by accumulating around the edges of the wound. Treatment with two doses of G8:3DNA:Dox completely eliminated G8+/α-SMA+ cells throughout the explant. These experiments demonstrate that Myo/Nog cells are the source of myofibroblasts in long-term cultures of anterior human lens tissue and mAb:3DNA nanocarriers specifically and effectively deliver cytotoxic cargo to a subpopulation of cells without off-target effects. G8:3DNA:Dox has the potential to reduce PCO following cataract surgery.

Development of mannose-anchored thiolated amphotericin B nanocarriers for treatment of visceral leishmaniasis.

Aim:Our goal was to improve treatment outcomes for visceral leishmaniasis by designing nanocarriers that improve drug biodistribution and half-life. Thus, long-acting mannose-anchored thiolated chitosan amphotericin B nanocarrier complexes (MTC AmB) were developed and characterized.Materials & methods:A mannose-anchored thiolated chitosan nanocarrier was manufactured and characterized. MTC AmB was examined for cytotoxicity, biocompatibility, uptake and antimicrobial activities.Results:MTC AmB was rod shaped with a size of 362 nm. MTC AmB elicited 90% macrophage viability and 71-fold enhancement in drug uptake compared with native drug. The antileishmanial IC50 for MTC AmB was 0.02 μg/ml compared with 0.26 μg/ml for native drug.Conclusion:These studies show that MTC can serve as a platform for clearance of Leishmania in macrophages.

Enhanced protein internalization and efficient endosomal escape using polyampholyte-modified liposomes and freeze concentration.

Here we show a new strategy for efficient freeze concentration-mediated cytoplasmic delivery of proteins, obtained via the endosomal escape property of polyampholyte-modified liposomes. The freeze concentration method successfully induces the efficient internalization of proteins simply by freezing cells with protein and nanocarrier complexes. However, the mechanism of protein internalization remains unclear. Here, we designed a novel protein delivery carrier by modifying liposomes through incorporating hydrophobic polyampholytes therein. These complexes were characterized for particle size, encapsulation efficiency, and cytotoxicity. Flow cytometry and microscopic analysis showed that the adsorption and internalization of protein-loaded polyampholyte-modified liposomes after freezing were enhanced compared with that observed in unfrozen complexes. Inhibition studies demonstrated that the internalization mechanism differs between unmodified and polyampholyte-modified liposomes. Furthermore, polyampholyte-modified liposomes exhibited high efficacy in facilitating endosomal escape to enhance protein delivery to the cytoplasm with low toxicity. These results strongly suggest that the freeze concentration-based strategy could be widely utilised for efficient cargo delivery into the cytoplasm in vitro not only in cancer treatment but also for gene therapy as well.

Norbornene derived nanocarrier reduces isoniazid mediated liver toxicity: assessment in HepG2 cell line and zebrafish model

The aim of this study was to investigate the protective effect of the stimuli-responsive norbornene-based nanocarrier complex of isoniazid, compared to pure isoniazid, on liver cells, byin vivoandin vitromethods.

Characterization of Nanocarrier Complexes with Plasmid DNA using SEM, TEM and AFM

Characterization of Nanocarrier Complexes with Plasmid DNA using SEM, TEM and AFM

Femto- to micro-second photobehavior of photosensitizer drug trapped within a cyclodextrin dimer

The interactions of 5,10,15,20-tetrakis(4-sulfonatophenyl)-porphyrin (TSPP, a singlet oxygen photosensitiser molecule) with a hexa-2,4-diynediyl bridged β-cyclodextrin dimer (CD-CD) in aqueous solutions of pH 7 were studied using steady-state UV-visible absorption/emission and femto- to millisecond time-resolved spectroscopy. TSPP forms 1 : 1 complexes with CD-CD (K(e) = 1.9 × 10(8) M(-1) at 293 K). The value of K(e) indicates a high affinity of TSPP to form complexes with CD-CD. The chemical nano-cavity has a notable effect on the fluorescence lifetimes of the Q(x) state (9.3 ns in water and 10.8 ns in CD-CD). The rotational times (410 ps for TSPP in water and 0.03 ns (12%) and 1.1 ns (88%) for the TSPP:CD-CD complexes) indicate the robustness of the formed entities, and fast depolarization of emission, most probably involving the porphyrin skeleton and phenyl ring motions. The ultrafast femtosecond component (60-100 fs) of TSPP is moderately affected by the confining environment, which instead strongly influences the ps component (1-2 ps in water and 5 ps within CD-CD) assigned to the vibrational relaxation of the Q(x) state. Moreover, a 50 ps component emerges in the emission transients in the 640-720 nm range, and which is assigned to a thermalization of the hot Q(x) state. The effect of O2 on the triplet state of the encapsulated TSPP was also studied and discussed in light of the shielding effect of the CD-CD cavity. We observed comparable quantum yield (0.62 and 0.69) of the generated singlet molecular oxygen of TSPP without and with CD-CD. We believe that our results on the molecular interaction between TSPP and CD-CD from femtosecond to millisecond regime at both ground and electronically first excited states give relevant information for improving our understanding of this kind of caged drugs, and thus for a better design of drug:nanocarrier complexes. A particular implication for the use of CD-CD as a drug carrier is the high affinity of this host for complex formation with TSPP, while the yield of singlet oxygen generation is still high.

Systemic Delivery of siRNA by Chimeric Capsid Protein: Tumor Targeting and RNAi Activity in Vivo

Recently, we reported that a chimeric capsid protein assembled into a macromolecular container-like structure with capsid shell and the resulting siRNA/capsid nanocarrier complexes efficiently suppressed RFP gene expression in the cell culture system. To extend RNAi to the in vivo applications, we here demonstrated that the siRNA/capsid nanocarrier complexes could have tumor-specific targeting ability in vivo as well as the increased stability of siRNA during body circulation. When systemically administered, our siRNA/capsid nanocarrier complexes delivered siRNA to tumor tissues and efficiently suppressed RFP gene expression in tumor-bearing mice. The enhanced longevity of siRNA in vivo could be explained by shielding effect derived from the capsid shell, where the encapsulated siRNAs are protected from nucleases in plasma. The multivalent RGD peptides on shell surface, as a result of self-assembling of capsid protein subunits, showed efficient delivery of siRNA to the tumor tissues in vivo, due to the RGD-mediated binding to integrin receptors overexpressed on tumor cells. Moreover, the prolonged in vivo circulation time of our siRNA/capsid nanocarrier complexes increased the potential to serve as siRNA carriers for optimal in vivo RNAi. These results provide an alternative approach to systemically deliver siRNA to the tumor sites as well as to enhance the stability of siRNA in vivo. Therefore, our results revealed the promising potential of our capsid nanocarrier system as a therapeutic siRNA carrier for cancer treatment.