Development of an efficient liposomal DOX delivery formulation for HCC therapy by targeting CK2α.

Hepatocellular carcinoma (HCC) is a digestive tract cancer with high mortality and poor prognosis, especially in China. Current chemotherapeutic drugs lead to poor prognosis, low efficacy, and high side effects due to weak targeting specificity and rapidly formed multidrug resistance (MDR). Based on the previous studies on the doxorubicin (DOX) formulation for cancer targeting therapy, we developed a novel DOX delivery formulation for the targeting chemotherapy of HCC and DOX resistant HCC. HCSP4 was previously screened and casein kinase 2α (CK2α) was predicted as its specific target on HCC cells in our lab. In the study, miR125a-5p was firstly predicted as an MDR inhibiting miRNA, and then CK2α was validated as the target of HCSP4 and miR125a-5p using CK2α-/-HepG2 cells. Based on the above, an HCC targeting and MDR inhibiting DOX delivery liposomal formulation, HCSP4/Lipo-DOX/miR125a-5p was synthesized and tested for its HCC therapeutic efficacy in vitro. The results showed that the liposomal DOX delivery formulation targeted to HCC cells specifically and sensitively, and presented the satisfied therapeutic efficacy for HCC, particularly for DOX resistant HCC. The potential therapeutic mechanism of the DOX delivery formulation was explored, and the formulation inhibited the expression of MDR-relevant genes including ATP-binding cassette subfamily B member 1 (ABCB1, also known as P-glycoprotein), ATP-binding cassette subfamily C member 5 (ABCC5), enhancer of zeste homolog 2 (EZH2), and ATPase Na+/K+ transporting subunit beta 1 (ATP1B1). Our study presents a novel targeting chemotherapeutic drug formulation for the therapy of HCC, especially for drug resistant HCC, although it is primarily and needs further study in vivo, but provided a new strategy for the development of novel anticancer drugs.

Diminishing Self-Discharge of High-Loading Li-S Batteries with Oxygen-Rich Biomass Carbon Interlayers.

Lithium-sulfur batteries (Li-S) have possessed gratifying development in the past decade due to their high theoretical energy density. However, the severe polysulfide shuttling provokes undesirable self-discharge effect, leading to low energy efficiency in Li-S batteries. Herein, an interlayer composed of oxygen-rich carbon nanosheets (OCN) derived from bagasse is elaborated to suppress the shuttle effect and reduce the resultant self-discharge effect. The OCN interlayer is able to physically block the shuttling behavior of polysulfides and its oxygen-rich functional groups can strongly interact with polysulfides via O-S bonds to chemically immobilize mobile polysulfides. The self-discharge test for seven days further shows that the self-discahrge rate is diminished by impressive 93 %. As a result, Li-S batteries with the OCN interlayer achieve an ultrahigh discharge specific capacity of 710 mAh g-1 at a high mass loading of 7.18 mg. The work provides a facile method for designing functional interlayers and opens a new avenue for realizing Li-S batteries with high energy efficiency.

Combined Dextran-Graft-Polyacrylamide/Zinc Oxide Nanocarrier for Effective Anticancer Therapy in vitro.

Introduction: Cancer chemotherapy faces two major challenges - high toxicity of active substances and tumor resistance to drugs. Low toxic nanocarriers in combination with anticancer agents can significantly increase the effectiveness of therapy. Modern advances in nanotechnology make it easy to create materials with the necessary physical and chemical properties. Methods: Two hybrid nanosystems of dextran-polyacrylamide/ zinc oxide nanoparticles (D-PAA/ZnO NPs) were synthesized in aqueous solution with zinc sulphate (D-PAA/ZnO NPs (SO42-)) and zinc acetate (D-PAA/ZnO NPs (-OAc)). The light absorption, fluorescence, dynamic light scattering and transmission electron microscopy for nanocomposite characterization were used. MTT, neutral red uptake and scratch assays were selected as fibroblasts cytotoxicity assays. Cytotoxicity was tested in vitro for normal fibroblasts, MAEC, prostate (LNCaP, PC-3, DU-145) and breast (MDA-MB-231, MCF-7) cancer cells lines. Immunocytochemical methods were used for detection of Ki-67, p53, Bcl-2, Bax, e-cadherin, N-cadherin and CD44 expression. Acridine orange was used to detect morphological changes in cells. Results: The radius of ZnO NPs (SO42-) was 1.5 nm and ZnO NPs (-OAc) was 2 nm. The nanosystems were low-toxic to fibroblasts, MAEC. Cells in the last stages of apoptosis with the formation of apoptotic bodies were detected for all investigated cancer cell lines. Proapoptotic proteins expression in cancer cells indicates an apoptotic death. Increased expression of E-cadherin and N-cadherin was registered for cancer cells line LNCaP, PC-3, DU-145 and MCF-7 after 48 h incubation with D-PAA/ZnO NPs (SO42-). Conclusion: The nanosystems were low-toxic to fibroblasts, MAEC. The D-PAA/ZnO NPs nanosystem synthesized using zinc sulphate demonstrates high cytotoxicity due to destruction of various types of cancer cells in vitro and potentially increases adhesion between cells. Thus, our findings indicate the selective cytotoxicity of D-PAA/ZnO NPs against cancer cells and can be potentially used for cancer treatment.

The roles EpCAM plays to enhance the malignancy of gastric cancer.

BACKGROUND: Gastric cancer (GC) remains a global challenge due to its high morbidity and mortality rates especially in Asia as well as poor response to treatment. As a member of the adhesion protein family and transmembrane glycoprotein, EpCAM expressed excessively in cancer cells including GC cells. The database assay showed that EpCAM is excessively expressed and easily mutated in cancers, especially in early stage of GC. METHODS: To explore the roles EpCAM plays in oncogenesis and progression of GC, the expression of EpCAM was deleted in GC cells with CRISPR/Cas9 method, and then the changes of cell proliferation, apoptosis, motility and motility associated microstructures in EpCAM-deleted GC cells (EpCAM-/-SGC7901) were detected to evaluate the rules EpCAM played. RESULTS: The results showed that EpCAM deletion caused cell proliferation, motility and the development of motility-relevant microstructures inhibited significantly, apoptotic trend and contact inhibition enhanced in EpCAM-deleted GC cells. The results of western blot suggested that EpCAM modulates the expression of epithelial/endothelial mesenchymal transition (EMT) correlated genes. All results as above indicated that EpCAM plays important roles to enhance the oncogenesis, malignancy and progression as a GC enhancer. CONCLUSIONS: Combining our results and published data together, the interaction of EpCAM with other proteins was also discussed and concluded in the discussion. Our results support that EpCAM can be considered as a novel target for the diagnosis and therapy of GC in future.

Numerical Analysis of Stable (FAPbI3)0.85(MAPbBr3)0.15-Based Perovskite Solar Cell with TiO2/ZnO Double Electron Layer.

Although perovskite solar cells have achieved excellent photoelectric conversion efficiencies, there are still some shortcomings, such as defects inside and at the interface as well as energy level dislocation, which may lead to non-radiative recombination and reduce stability. Therefore, in this study, a double electron transport layer (ETL) structure of FTO/TiO2/ZnO/(FAPbI3)0.85(MAPbBr3)0.15/Spiro-OMeTAD is investigated and compared with single ETL structures of FTO/TiO2/(FAPbI3)0.85(MAPbBr3)0.15/Spiro-OMeTAD and FTO/ZnO/(FAPbI3)0.85(MAPbBr3)0.15/Spiro-OMeTAD using the SCAPS-1D simulation software, with special attention paid to the defect density in the perovskite active layer, defect density at the interface between the ETL and the perovskite active layer, and temperature. Simulation results reveal that the proposed double ETL structure could effectively reduce the energy level dislocation and inhibit the non-radiative recombination. The increases in the defect density in the perovskite active layer, the defect density at the interface between the ETL and the perovskite active layer, and the temperature all facilitate carrier recombination. Compared with the single ETL structure, the double ETL structure has a higher tolerance for defect density and temperature. The simulation outcomes also confirm the possibility of preparing a stable perovskite solar cell.

The Synergistic Inhibitions of Tungstate and Molybdate Anions on Pitting Corrosion Initiation for Q235 Carbon Steel in Chloride Solution.

In this work, the synergistic inhibitions of tungstate (WO42-) and molybdate (MoO42-) anions, including role and mechanism, on the initiation of pitting corrosion (PC) for Q235 carbon steel in chloride (Cl-) solution were investigated with electrochemical and surface techniques. The pitting potential (Ep) of the Q235 carbon steel in WO42- + MoO42- + Cl- solution was more positive than that in WO42- + Cl- or MoO42- + Cl- solution; at each Ep, both peak potential and affected region of active pitting sites in WO42- + MoO42- + Cl- solution were smaller than those in WO42- + Cl- or MoO42- + Cl- solution. WO42- and MoO42- showed a synergistic role to inhibit the PC initiation of the Q235 carbon steel in Cl- solution, whose mechanism was mainly attributed to the influences of two anions on passive film. Besides iron oxides and iron hydroxides, the passive film of the Q235 carbon steel formed in WO42- + Cl-, MoO42- + Cl-, or WO42- + MoO42- + Cl- solution was also composed of FeWO4 plus Fe2(WO4)3, Fe2(MoO4)3, or Fe2(WO4)3 plus Fe2(MoO4)3, respectively. The film resistance and the defect quantity for Fe2(WO4)3 plus Fe2(MoO4)3 film were larger and smaller than those for FeWO4 plus Fe2(WO4)3 film and Fe2(MoO4)3 film, respectively; for the inhibition of PC initiation, Fe2(WO4)3 plus Fe2(MoO4)3 film provided better corrosion resistance to Q235 carbon steel than FeWO4 plus Fe2(WO4)3 film and Fe2(MoO4)3 film did.

Cytotoxicity of Hybrid Noble Metal-Polymer Composites.

The aim of the present research was to assess the cytotoxicity of gold and silver nanoparticles synthesized into dextran-graft-polyacrylamide (D-PAA) polymer nanocarrier, which were used as a basis for further preparation of multicomponent nanocomposites revealed high efficacy for antitumor therapy. The evaluation of the influence of Me-polymer systems on the viability and metabolic activity of fibroblasts and eryptosis elucidating the mechanisms of the proeryptotic effects has been done in the current research. The nanocomposites investigated in this study did not reduce the survival of fibroblasts even at the highest used concentration. Our findings suggest that hybrid Ag/D-PAA composite activated eryptosis via ROS- and Ca2+-mediated pathways at the low concentration, in contrast to other studied materials. Thus, the cytotoxicity of Ag/D-PAA composite against erythrocytes was more pronounced compared with D-PAA and hybrid Au/polymer composite. Eryptosis is a more sensitive tool for assessing the biocompatibility of nanomaterials compared with fibroblast viability assays.

Thermoresponsive Zinc TetraPhenylPorphyrin Photosensitizer/Dextran Graft Poly(N-IsoPropylAcrylAmide) Copolymer/Au Nanoparticles Hybrid Nanosystem: Potential for Photodynamic Therapy Applications.

The thermoresponsive Zinc TetraPhenylPorphyrin photosensitizer/Dextran poly (N-isopropylacrylamide) graft copolymer/Au Nanoparticles (ZnTPP/D-g-PNIPAM/AuNPs) triple hybrid nanosystem was synthesized in aqueous solution as a nanodrug for potential use in thermally driven and controlled photodynamic therapy applications. The aqueous solution of the nanosystem has demonstrated excellent stability in terms of aggregation and sedimentation several days after preparation. Optimal concentrations of the components of hybrid nanosystem providing the lowest level of aggregation and the highest plasmonic enhancement of electronic processes in the photosensitizer molecules have been determined. It has been revealed that the shrinking of D-g-PNIPAM macromolecule during a thermally induced phase transition leads to the release of both ZnTPP molecules and Au NPs from the ZnTPP/D-g-PNIPAM/AuNPs macromolecule and the strengthening of plasmonic enhancement of the electronic processes in ZnTPP molecules bound with the polymer macromolecule. The 2.7-fold enhancement of singlet oxygen photogeneration under resonant with surface plasmon resonance has been observed for ZnTPP/D-g-PNIPAM/AuNPs proving the plasmon nature of such effect. The data obtained in vitro on wild strains of Staphylococcus aureus have proved the high potential of such nanosystem for rapid photodynamic inactivation of microorganisms particular in wounds or ulcers on the body surface.

Self-Matrix N-Doped Room Temperature Phosphorescent Carbon Dots Triggered by Visible and Ultraviolet Light Dual Modes.

The synthesis of room temperature phosphorescent carbon dots (RTP-CDs) without any matrix is important in various applications. In particular, RTP-CDs with dual modes of excitation are more interesting. Here, we successfully synthesized matrix-free carbonized polymer dots (CPDs) that can generate green RTP under visible and ultraviolet light dual-mode excitation. Using acrylic acid (AA) and ammonium oxalate as precursors, a simple one-pot hydrothermal method was selected to prepare AA-CPDs. Here, acrylic acid is easy to polymerize under high temperature and high pressure, which makes AA-CPDs form a dense cross-linked internal structure. Ammonium oxalate as a nitrogen source can form amino groups during the reaction, which reacts with a large number of pendant carboxyl groups on the polymer chains to further form a cross-linked structure. The carboxyl and amino groups on the surface of AA-CPDs are connected by intermolecular hydrogen bonds. These hydrogen bonds can provide space protection (isolation of oxygen) around the AA-CPDs phosphor, which can stably excite the triplet state. This self-matrix structure effectively inhibits the non-radiative transition by blocking the intramolecular motion of CPDs. Under the excitation of WLED and 365 nm ultraviolet light, AA-CPDs exhibit the phosphorescence emission at 464 nm and 476 nm, respectively. The naked-eye observation exceeds 5 s and 10 s, respectively, and the average lifetime at 365 nm excitation wavelength is as long as 412.03 ms. In addition, it successfully proved the potential application of AA-CPDs in image anti-counterfeiting.

Selection and identification of a specific peptide binding to ovarian cancer cells from a phage-displayed peptide library.

OBJECTIVES: Ovarian cancer is one of the most fatal gynecological malignancies. It is emergently needed to select a novel molecular fragment as a targeting element for the future development of molecular imaging diagnosis and targeting chemotherapy to ovarian cancer. RESULTS: After five rounds of biopanning, a total of 44 positive phage clones were selected from final phage displayed peptide library. Nine consensus sequences were found based on the assay of sequencing results, then one clone of each consensus group was characterized and identified further by immunofluorescence assay. The result showed the phage clone R20 presents best targeting capacity. Then we synthesized peptide (OSP2) clone R20 displayed, it was characterized with high specificity and sensitivity binding to human ovarian cancer by a tissue chip assay. The target of OSP2 was predicted and docked as human carbonic anhydrase XII (CA12), an important protein usually deregulated in cancer. CONCLUSIONS: Taken together, OSP2 and its target indicate a novel investigation way in future to develop novel agent or drug delivery formulation for molecular imaging diagnosis and targeting chemotherapy of ovarian cancer.

Spray-Assisted Interfacial Polymerization to Form CuII/I@CMC-PANI Film: An Efficient Dip Catalyst for A3 Reaction.

A novel and interesting method for the preparation of carboxymethylcellulose-polyaniline film-supported copper catalyst (CuII/I@CMC-PANI) has been developed via spray-assisted interfacial polymerization. Using copper sulfate as an initiator, spraying technology was introduced to form a unique interface that is perfectly beneficial to the polymerization of aniline monomers onto carboxymethylcellulose macromolecule chains. To further confirm the composition and structure of the as-prepared hybrid film, it was systematically characterized by inductively coupled plasma (ICP), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and thermogravimetric analysis (TGA) techniques. The Cu content in the fresh CuII/I@CMC-PANI film was determined to be 1.805 mmol/g, and spherical nanoparticles with an average size of ca. 10.04 nm could be observed in the hybrid film. The CuII/I@CMC-PANI hybrid film was exerted as a dip catalyst to catalyze the aldehyde-alkyne-amine (A3) coupling reactions. High yields of the products (up to 97%) were obtained in this catalytic system, and the catalyst could be easily picked up from the reaction mixture by tweezers and reused for at least six consecutive runs, without any discernible losses in its activity in the model reaction. The dip catalyst of CuII/I@CMC-PANI, with easy fabrication, convenient deployment, superior catalytic activity, and great reusability, is expected to be very useful in organic synthesis.

Combining Active Carbonic Anhydrase with Nanogels: Enzyme Protection and Zinc Sensing.

BACKGROUND: Due to its excellent biocompatibility, the polyacrylamide (PAAm) hydrogel has shown great potential for the immobilization of enzymes used in biomedical applications. The major challenge involved is to preserve, during the immobilization process, both the biological activity and the structural integrity of the enzymes. Here we report, for the first time, a proof-of-concept study for embedding active carbonic anhydrase (CA) into polyacrylamide (PAAm) nanogels. By immobilizing CA in these nanogels, we hope to provide important advantages, such as matrix protection of the CA as well as its targeted delivery, and also for potentially using these nanogels as zinc nano-biosensors, both in-vitro and in-vivo. METHODS AND RESULTS: Two methods are reported here for CA immobilization: encapsulation and surface conjugation. In the encapsulation method, the common process was improved, so as to best preserve the CA, by 1) using a novel biofriendly nonionic surfactant system (Span 80/Tween 80/Brij 30) and 2) using an Al2O3 adsorptive filtration purification procedure. In the surface conjugation method, blank PAAm nanogels were activated by N-hydroxysuccinimide and the CA was cross-linked to the nanogels. The amount of active CA immobilized in the nanoparticles was quantified for both methods. Per 1 g nanogels, the CA encapsulated nanogels contain 11.3 mg active CA, while the CA conjugated nanogels contain 22.5 mg active CA. Also, the CA conjugated nanoparticles successfully measured free Zn2+ levels in solution, with the Zn2+ dissociation constant determined to be 9 pM. CONCLUSION: This work demonstrates universal methods for immobilizing highly fragile bio-macromolecules inside nanoparticle carriers, while preserving their structural integrity and biological activity. The advantages and limitations are discussed, as well as the potential biomedical applications.

LEF1 Enhances the Progression of Colonic Adenocarcinoma via Remodeling the Cell Motility Associated Structures.

Lymphoid enhancer-binding factor 1 (LEF1) is a key transcription factor mediating the Wnt signaling pathway. LEF1 is a regulator that is closely associated with tumor malignancy and is usually upregulated in cancers, including colonic adenocarcinoma. The underlying molecular mechanisms of LEF1 regulation for colonic adenocarcinoma progression remain unknown. To explore it, the LEF1 expression in caco2 cells was inhibited using an shRNA approach. The results showed that downregulation of LEF1 inhibited the malignancy and motility associated microstructures, such as polymerization of F-actin, ß-tubulin, and Lamin B1 in caco2 cells. LEF1 inhibition suppressed the expression of epithelial/endothelial-mesenchymal transition (EMT) relevant genes. Overall, the current results demonstrated that LEF1 plays a pivotal role in maintaining the malignancy of colonic adenocarcinoma by remodeling motility correlated microstructures and suppressing the expression of EMT-relevant genes. Our study provided evidence of the roles LEF1 played in colonic adenocarcinoma progression, and suggest LEF1 as a potential target for colonic adenocarcinoma therapy.

A novel targeted delivery system for drug-resistant hepatocellular carcinoma therapy.

Hepatocellular carcinoma (HCC) is a severe malignant disease threatening human life. Current chemotherapy methods usually result in poor prognosis with low treatment efficacy and high side effects because of weak targeting specificity and fast acquisition of multidrug resistance (MDR). HCSP4 is a 12-aa peptide previously identified to specifically and sensitively bind to HCC cells and tissues. In this study, a novel class of HCC-targeting doxorubicin (DOX) delivery system, named HCSP4-Lipo-DOX-miR101, was synthesized and investigated for anticancer activity. HCSP4-Lipo-DOX-miR101 exhibited specific HCC targeting characteristics and satisfactory anticancer potency against HepG2 and HepG2/ADR cells, particularly HepG2/ADR cells. Moreover, the expression levels of genes closely related to membrane transport and cancer growth were significantly suppressed. This finding suggests that HCSP4-Lipo-DOX-miR101 can cause DOX-resistant HCC cell death and growth inhibition based on the targeting of MDR-related genes by miR-101. In conclusion, the findings of this study suggest that HCSP4-Lipo-DOX-miR101 may serve as a promising novel targeted delivery system for improving the therapeutic efficiency of drug-resistant hepatocellular carcinoma.

Preparation of phosphatidylcholine nanovesicles containing bacteriocin CAMT2 and their anti-listerial activity.

A novel bacteriocin CAMT2, produced by Bacillus amyloliquefaciens ZJHD3-06, has potential as a natural biopreservative for the control of food-borne spoilage and pathogenic bacteria. To avoid interaction of CAMT2 with components of food that may adversely impact its antibacterial activity, CAMT2 was encapsulated into nanovesicles prepared from soybean phosphatidylcholine. The encapsulation of CAMT2 exhibited a limited impact on functional structure and crystallinity of bacteriocin CAMT2, but a high anti-listerial activity in agar, and increase its stability in food at refrigeration temperature (4 °C). The results also showed that both encapsulated and free CAMT2 had good anti-listerial effect in skim milk at refrigeration temperature. However, encapsulated CAMT2 performed better than free CAMT2 against Listeria in whole milk. These results showed that nano-encapsulation is an effective method of protecting bacteriocin from fat in milk and retaining its antimicrobial efficacy.

The further characterization of the peptide specifically binding to gastric cancer.

Targeting peptide has been considered to be useful as a small molecule probe leading to multifunctional properties for both imaging detection and targeting therapy. Thus, the identification of novel targets is urgently needed to develop innovative agents to effectively control gastric cancer metastasis and progression. Previously, we reported a novel 12-mer peptide, GP-5 (IHKDKNAPSLVP), binding to gastric carcinoma (GC) cells specifically and sensitively, and it was screened by using a phage displayed peptide library and primarily analyzed. In this study, it was further identified via fluorescence microscopy, flow cytometry, tissue chip and other methods. Our results indicated that the peptide GP-5 presents a particularly high affinity and specificity to GC cells and tissues, whereas only background detection occurred with other control cancer cells, cancer tissues or normal tissues. Taken together, all results support that the peptide GP-5 is a potential candidate to be developed as a useful molecule fragment for the imaging detection and targeting therapy of GC.

Screening of a specific peptide binding to esophageal squamous carcinoma cells from phage displayed peptide library.

To select a specifically binding peptide for imaging detection of human esophageal squamous cell carcinoma (ESCC), a phage-displayed 12-mer peptide library was used to screen the peptide that bind to ESCC cells specifically. After four rounds of bio-panning, the phage recovery rate gradually increased, and specific phage clones were effectively enriched. The 60 randomly selected phage clones were tested using cellular enzyme-linked immunosorbent assay (ELISA), and 41 phage clones were identified as positive clones with the over 2.10 ratio of absorbance higher than other clones, IRP and PBS controls. From the sequencing results of the positive clones, 14 peptide sequences were obtained and ESCP9 consensus sequence was identified as the peptide with best affinity to ESCC cells via competitive inhibition, fluorescence microscopy, and flow cytometry. The results indicate that the peptide ESCP9 can bind to ESCC cells specifically and sensitively, and it is a potential candidate to be developed as an useful molecule to the imaging detection and targeting therapy for ESCC.

[Exploration Research of Treatment Effect Improvement of Transcutaneous Electrical Nerve Stimulation Using Parameter-changing Chaotic Signal].

This article presents a transcutaneous electric stimulator that is based on chaotic signal. Firstly, we in the study used the MATLAB platform in the PC to generate chaotic signal through the chaos equation, and then we transferred the signal out by data acquisition equipment of USB-6251 manufactured by NI Company. In order to obtain high-power signal for transcutaneous electric stimulator, we used the chip of LM3886 to amplify the signal. Finally, we used the power-amplified chaotic signal to stimulate the internal nerve of human through the electrodes fixed on the skin. We obtained different stimulation effects of transcutaneous electric stimulator by changing the parameters of chaotic model. The preliminary test showed that the randomness of chaotic signals improved the applicability of electrical stimulation and the rules of chaos ensured that the stimulation was comfort. The method reported in this paper provides a new way for the design of transcutaneous electric stimulator.

Hydrogel nanoparticles with covalently linked coomassie blue for brain tumor delineation visible to the surgeon.

Delineation of tumor margins is a critical and challenging objective during brain cancer surgery. A tumor-targeting deep-blue nanoparticle-based visible contrast agent is described, which, for the first time, offers in vivo tumor-specific visible color staining. This technology thus enables color-guided tumor resection in real time, with no need for extra equipment or special lighting conditions. The visual contrast agent consists of polyacrylamide nanoparticles covalently linked to Coomassie Blue molecules (for nonleachable blue color contrast), which are surface-conjugated with polyethylene glycol and F3 peptides for efficient in vivo circulation and tumor targeting, respectively.

Methylene blue covalently loaded polyacrylamide nanoparticles for enhanced tumor-targeted photodynamic therapy.

The use of targeted nanoparticles (NPs) as a platform for loading photosensitizers enables selective accumulation of the photosensitizers in the tumor area, while maintaining their photodynamic therapy (PDT) effectiveness. Here two novel kinds of methylene blue (MB)-conjugated polyacrylamide (PAA) nanoparticles, MBI-PAA NPs and MBII-PAA NPs, based on two separate MB derivatives, are developed for PDT. This covalent conjugation with the NPs (i) improves the loading of MB, (ii) prevents any leaching of MB from the NPs and (iii) protects the MB from the effects of enzymes in the biological environment. The loading of MB into these two kinds of NPs was controlled by the input amount, resulting in concentrations with optimal singlet oxygen production. For each of the MB-NPs, the highest singlet oxygen production was found for an MB loading of around 11 nmol mg(-1). After attachment of F3 peptide groups, for targeting, each of these NPs was taken up, selectively, by MDA-MB-435 tumor cells, in vitro. PDT tests demonstrated that both kinds of targeted NPs resulted in effective tumor cell kill, following illumination, while not causing dark toxicity.