The MYB transcription factor Seed Shattering 11 controls seed shattering by repressing lignin synthesis in African rice.

African cultivated rice (Oryza glaberrima Steud.) was domesticated from its wild progenitor species (Oryza barthii) about 3000 years ago. Seed shattering is one of the main constraints on grain production in African cultivated rice, which causes severe grain losses during harvest. By contrast, Asian cultivated rice (Oryza sativa) displays greater resistance to seed shattering, allowing higher grain production. A better understanding in regulation of seed shattering would help to improve harvesting efficiency in African cultivated rice. Here, we report the map-based cloning and characterization of OgSH11, a MYB transcription factor controlling seed shattering in O. glaberrima. OgSH11 represses the expression of lignin biosynthesis genes and lignin deposition by binding to the promoter of GH2. We successfully developed a new O. glaberrima material showing significantly reduced seed shattering by knockout of SH11 in O. glaberrima using CRISPR-Cas9 mediated approach. Identification of SH11 not only supplies a new target for seed shattering improvement in African cultivated rice, but also provides new insights into the molecular mechanism of abscission layer development.

Repair of orbital bone defects in canines using grafts of enriched autologous bone marrow stromal cells.

BACKGROUND: Bone tissue engineering is a new approach for the repair of orbital defects. The aim of the present study was to explore the feasibility of tissue-engineered bone constructed using bone marrow stromal cells (BMSCs) that were rapidly isolated and concentrated from bone marrow (BM) by the red cell lysis method, then combined with ß-tricalcium phosphate (ß-TCP) to create grafts used to restore orbital bone defects in canines. METHODS: In the experimental group, grafts were constructed using BMSCs obtained by red cell lysis from 20 ml bone marrow, combined with ß-TCP and BM via the custom-made stem cell-scaffold device, then used to repair 10 mm diameter medial orbital wall bony defects in canines. Results were compared with those in groups grafted with BM/ß-TCP or ß-TCP alone, or with defects left untreated as controls. The enrichment of BMSCs and nucleated cells (NCs) in the graft was calculated from the number in untreated bone marrow and in suspensions after red cell lysis. Spiral computed tomography (CT) scans were performed 1, 4, 12 and 24 weeks after implantation in all groups. Gross examination, micro-CT and histological measurements were performed 24 weeks after surgery. The results were analyzed to evaluate the efficacy of bone repair. RESULTS: The number of NCs and of colony-forming units within the scaffolds were increased 54.8 times and 53.4 times, respectively, compared with untreated bone marrow. In the BMSC-BM/ß-TCP group, CT examination revealed that the scaffolds were gradually absorbed and the bony defects were restored. Micro-CT and histological examination confirmed that the implantations led to good repair of the defects, with 6 out 8 orbital defects completely restored in the experimental group, while by contrast, the grafts in the control groups did not fully repair the bony defects, a difference which was statistically significant (p<0.05). CONCLUSIONS: Tissue-engineered bone, constructed using BMSCs isolated by red cell lysis of BM, can restore critical-sized orbital wall defects in canines.

Gecko-inspired bidirectional double-sided adhesives.

A new concept of gecko-inspired double-sided adhesives (DSAs) is presented. The DSAs, constructed by dual-angled (i.e. angled base and angled tip) micro-pillars on both sides of the backplane substrate, are fabricated by combinations of angled etching, mould replication, tip modification, and curing bonding. Two types of DSA, symmetric and antisymmetric (i.e. pillars are patterned symmetrically or antisymmetrically relative to the backplane), are fabricated and studied in comparison with the single-sided adhesive (SSA) counterparts through both non-conformal and conformal tests. Results indicate that the DSAs show controllable and bidirectional adhesion. Combination of the two pillar-layers can either amplify (for the antisymmetric DSA, providing a remarkable and durable adhesion capacity of 25.8 ± 2.8 N cm⁻² and a high anisotropy ratio of ∼8) or counteract (for the symmetric DSA, generating almost isotropic adhesion) the adhesion capacity and anisotropic level of one SSA (capacity of 16.2 ± 1.7 N cm⁻² and anisotropy ratio of ∼6). We demonstrate that these two DSAs can be utilized as a facile fastener for two individual objects and a small-scale delivery setup, respectively, complementing the functionality of the commonly studied SSA. As such, the double-sided patterning is believed to be a new branch in the further development of biomimetic dry adhesives.

Novel therapeutic perspectives for wet age-related macular degeneration: RGD-modified liposomes loaded with 2-deoxy-D-glucose as a promising nanomedicine.

Choroidal neovascularization (CNV), characterized as a prominent feature of wet age-related macular degeneration (AMD), is a primary contributor to visual impairment and severe vision loss globally, while the prevailing treatments are often unsatisfactory. The development of conventional treatment strategies has largely been based on the understanding that the angiogenic switch of endothelial cells is dictated by angiogenic growth factors alone. Even though treatments targeting vascular endothelial growth factor (VEGF), like Ranibizumab, are widely administered, more than half of the patients still exhibit inadequate or null responses, emphasizing the imperative need for solutions to this problem. Here, aiming to explore therapeutic strategies from a novel perspective of endothelial cell metabolism, a biocompatible nanomedicine delivery system is constructed by loading RGD peptide-modified liposomes with 2-deoxy-D-glucose (RGD@LP-2-DG). RGD@LP-2-DG displayed good targeting performance towards endothelial cells and excellent in vitro and in vivo inhibitory effects on neovascularization were demonstrated. Moreover, our mechanistic studies revealed that 2-DG interfered with N-glycosylation, leading to the inhibition of vascular endothelial growth factor receptor 2 (VEGFR2) and its downstream signaling. Notably, the remarkable inhibitory effect on neovascularization and biocompatibility of RGD@LP-2-DG render it a highly promising and clinically translatable therapeutic candidate for the treatment of wet AMD and other angiogenic diseases, particularly in patients who are unresponsive to currently available treatments.

A gecko-inspired double-sided adhesive.

Geckos' outstanding abilities to adhere to various surfaces are widely credited to the large actual contact areas of the fibrillar and hierarchical structures on their feet. These special features regulate the essential structural compliance for every attachment and thus provide robust yet reversible adhesions. Inspired by gecko's feet and our commonly used double-faced tape, we have successfully fabricated a gecko-inspired double-sided dry adhesive by using porous anodic alumina template assisted nano-wetting on a stiff polymer. It was determined that the obtained 2-sided structure showed largely decreased effective stiffness compared with its 1-sided counterpart, which favored better compliance and interfacial integrity. We also demonstrated that the repeatable double-sided adhesive improved the macroscopic normal and shear adhesion capacities over the widely-studied 1-side structure by ~50% and ~85%, respectively. By using the synthetic double-sided adhesive, the usage of traditional pressure-sensitive/chemical adhesives could be well avoided. Besides, the double-sided nanostructures showed great potential in finding new interesting properties and practical applications for the synthetic dry adhesives.

Advances and Prospects in Materials for Craniofacial Bone Reconstruction.

The craniofacial region is composed of 23 bones, which provide crucial function in keeping the normal position of brain and eyeballs, aesthetics of the craniofacial complex, facial movements, and visual function. Given the complex geometry and architecture, craniofacial bone defects not only affect the normal craniofacial structure but also may result in severe craniofacial dysfunction. Therefore, the exploration of rapid, precise, and effective reconstruction of craniofacial bone defects is urgent. Recently, developments in advanced bone tissue engineering bring new hope for the ideal reconstruction of the craniofacial bone defects. This report, presenting a first-time comprehensive review of recent advances of biomaterials in craniofacial bone tissue engineering, overviews the modification of traditional biomaterials and development of advanced biomaterials applying to craniofacial reconstruction. Challenges and perspectives of biomaterial development in craniofacial fields are discussed in the end.

Stretchable and transparent alginate ionic gel film for multifunctional sensors and devices.

Flexible and stretchable substrates based on pure natural polymers have attracted widespread attention for next-generation "green" electronics. However, fabrication of stretchable and "green" electronic sensors with integrated high stretchability, optical transmittance and good conductivity still remains tremendous challenges. Herein, alginate ionic gel films (AIGFs) with integrated high stretchability (tensile strength of 4.13 MPa and 191.1 % fracture strain) and excellent transparent properties (transparency of ∼92 %) are achieved by the glycerol inducing physical crosslinking and CaCl2 initiating ionic crosslinking, a simple soaking and drying strategy. The obtained gel films not only exhibit good ionic conductivity, but also high reliability, wide-range sensing, and multiple sensitivity to external stimulus. More importantly, these ionic conductive gel films as green substrates are successfully utilized for construction of flexible and patterned optoelectronic devices. This promising strategy will open up new powerful routes to construct highly stretchable, transparent, and ionic conductive substrates for multifunctional sensors and devices.

Stretchable and sensitive sodium alginate ionic hydrogel fibers for flexible strain sensors.

Ionic conductive hydrogel fibers based on natural polymers provide an immense focus for a new generation of electronics due to their flexibility and knittability. The feasibility of utilizing pure natural polymer-based hydrogel fibers could be drastically improved if their mechanical and transparent performances satisfy the requirements of actual practice. Herein, we report a facile fabrication strategy for significantly stretchable and sensitive sodium alginate ionic hydrogel fibers (SAIFs), by glycerol initiating physical crosslinking and by CaCl2 inducing ionic crosslinking. The obtained ionic hydrogel fibers not only show significant stretchability (tensile strength of 1.55 MPa and fracture strain of ∼161 %), but also exhibit wide-range sensing, satisfactorily stable, rapidly responsive, and multiply sensitive abilities to external stimulus. In addition, the ionic hydrogel fibers have excellent transparency (over 90 % in a wide wavelength range), and good anti-evaporation and anti-freezing properties. Furthermore, the SAIFs have been easily knitted into a textile, and successfully applied as wearable sensors to recognize human motions, by observing the output electrical signals. Our methodology for fabrication intelligent SAIFs will shed light on artificial flexible electronics and other textile-based strain sensors.

Mesenchymal stem cells as a novel carrier for targeted delivery of gene in cancer therapy based on nonviral transfection.

The success of gene therapy relies largely on an effective targeted gene delivery system. Till recently, more and more targeted delivery carriers, such as liposome, nanoparticles, microbubbles, etc., have been developed. However, the clinical applications of these systems were limited for their several disadvantages. Therefore, design and development of novel drug/gene delivery vehicles became a hot topic. Cell-based delivery systems are emerging as an alternative for the targeted delivery system as we described previously. Mesenchymal stem cells (MSCs) are an attractive cell therapy carrier for the delivery of therapeutic agents into tumor sites mainly for their tumor-targeting capacities. In the present study, a nonviral vector, PEI(600)-Cyd, prepared by linking low molecular weight polyethylenimine (PEI) and ß-cyclodextrin (ß-CD), was used to introduce the therapeutical gene, tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL), to MSCs. Meanwhile, the characterization, transfection efficiency, cytotoxicity, cellular internalization, and its mechanism of this nonviral vector were evaluated. The in vitro expression of TRAIL from MSCs-TRAIL was demonstrated by both enzyme-linked immunosorbent assay and Western blot analysis. The lung tumor homing ability of MSCs was further confirmed by the in vitro and in vivo model. Moreover, the therapeutic effects as well as the safety of MSCs-TRAIL on lung metastases bearing C57BL/6 mice and normal C57BL/6 mice were also demonstrated. Our results supported both the effectiveness of nonviral vectors in transferring the therapeutic gene to MSCs and the feasibility of using MSCs as a targeted gene delivery carrier, indicating that MSCs could be a promising tumor target delivery vehicle in cancer gene therapy based on nonviral gene recombination.

Gene-carried chitosan-linked polyethylenimine induced high gene transfection efficiency on dendritic cells.

A dendritic cell (DC) networking system has become an attractive approach in cancer immunotherapy. Successful DC gene engineering depends on the development of transgene vectors. A cationic polymer, chitosan-linked polyethylenimine (PEI) (CP), possessing the advantages of both PEI and chitosan, has been applied in nonviral transfection of DCs. Physicochemical evaluation showed that CP/DNA complexes could form cationic nanoparticles. Compared with DCs transfected with commercial reagent, Lipofectamine2000, it showed higher transfection efficiency and lower cytotoxicity when DCs were transfected with CP/DNA complexes. A nuclear trafficking observation of CP/DNA complexes by a confocal laser scanning microscope further revealed that the CP could help DNA enter into the cytoplasm and finally into the nucleus of a DC. Finally, vaccination of DCs transfected with CP/DNA encoding gp100 slightly improved resistance to the B16BL6 melanoma challenge. This is the first report that CP polymer is used as a nonviral vector for DC gene delivery and DC vaccine. Essentially, these results might be helpful to design a promising nonviral vector for DC gene delivery.

[Synthesis of a supermolecular nanoparticle γ-hy-PC/Ada-Dox and its antitumor activity].

OBJECTIVE: To synthesize a (2-Hydroxypropyl)-γ-cyclodextrin-polyethylenimine/adamantane-conjugated doxorubicin (γ-hy-PC/Ada-Dox) based supramolecular nanoparticle with host-guest interaction and to identify its physicochemical characterizations and antitumor effect. METHODS: A novel non-viral gene delivery vector γ-hy-PC/Ada-Dox was synthesized based on host-guest interaction. 1H-NMR, NOESY, UV-Vis, XRD and TGA were used to confirm the structure of the vector. The DNA condensing ability of complexes was investigated by particle size, zeta potential and gel retardation assay. Cytotoxicity of complexes was determined by MTT assay in BEL-7402 and SMMC-7721 cells. Cell wound healing assay was performed in HEK293 and BEL-7404 cells. The transfection efficiency was investigated in HEK293 cells. H/E staining and cell uptake assay was performed in BEL-7402 cells. RESULTS: The structure of γ-hy-PC/Ada-Dox was characterized by 1H-NMR, NOESY, UV-Vis, XRD, TGA. The drug loading was 0.5% and 5.5%. Gel retardation assay showed that γ-hy-PC was able to completely condense DNA at N/P ratio of 2; 0.5% and 5.5% γ-hy-PC/Ada-Dox was able to completely condense DNA at N/P ratio of 3 and 4,respectively. The cytotoxicity of polymers was lower than that of PEI25KDa. The transfection efficiency of γ-hy-PC was higher than that of γ-hy-PC/Ada-Dox at N/P ratio of 30 in HEK293 cells; and the transfection efficiency was decreasing when Ada-Dox loading was increasing. Cell uptake assay showed that γ-hy-PC/Ada-Dox was able to carry drug and FAM-siRNA into cells. CONCLUSION: The novel vector γ-hy-PC/Ada-Dox has been developed successfully, which has certain transfection efficiency and antitumor activity.

[Anticancer effect of triptolide-polyethylenimine-cyclodextrin in vitro].

OBJECTIVE: To develop a drug delivery system triptolide-polyethylenimine-cyclodextrin and to evaluate its anticancer activity in vitro. METHODS: Triptolide was conjugated to polyethylenimine-cyclodextrin by N, N'-carbonyldiimidazole to form triptolide-polyethylenimine-cyclodextrin. (1)H-NMR, FT-IR and XRD were used to confirm its structure. The anticancer effect of the polymer was assessed by MTT assay, erasion trace test and hematoxylin-eosin staining. The potential to condense siRNA and to delivery siRNA into cytoplasm was demonstrated by gel retardation assay, zeta-potential determination and fluorescence staining. RESULTS: Triptolide was successfully conjugated to polyethylenimine-cyclodextrin and the conjugation rate of triptolide was 10% (w/w). siRNA was effectively condensed by the polymer at the N/P ratio of 5, and its particle size was 300 ±15 nm and zeta potential was 8 ±2.5 mV. MTT assay, erasion trace test and hematoxylin-eosin staining revealed that triptolide-polyethylenimine-cyclodextrin had anticancer effect and low cytotoxicity to normal cells. The polymer was able to deliver siRNA to the cytoplasm effectively as demonstrated by fluorescence staining. CONCLUSION: Triptolide-polyethylenimine-cyclodextrin is able to inhibit the growth and migration of cancer cells in vitro and to carry siRNA into cells effectively. It is potential to be used as a novel prodrug for co-delivery of gene and drug in cancer treatment.

[Characteristics of cationic polymers PEI-CyD, PEI-PHPA, PEE-PHPA and PEI25kD in vitro and in vivo].

OBJECTIVE: To study the characteristics of cationic polymers polyethylenimine-ß-cyclodextrin (PEI-CyD), polyethylenimine-poly-(3-hydroxypropyl)-aspartamide (PEI-PHPA), N,N-Dimethyldipropylenetriamine-Bis(3-aminopropyl)amine-aspartamide (PEE-PHPA) in vitro and in vivo. METHODS: PEI-PHPA, PEI-CyD and PEE-PHPA were synthesized and the chemistry structure of PEI-PHPA, PEI-CyD and PEE-PHPA was confirmed by (1)H-NMR. The particle size and zeta potential of these polymers were measured, and capacity of plasmid DNA condensation was tested. The inhibition of COS-7, A549, HEK293 and C6 cells was measured by MTT assay. The transfection efficiency was determined in HEK293 cell lines. The toxicity, tissue distribution and transfection efficiency of cationic polymers were tested in vivo. RESULTS: When the N/P of polymers/DNA at 30, the particle sizes were close 250 nm and the zeta-potential were near 35 mv. They were able to condense DNA at N/P ratio < 5. The MTT assay showed that the IC(50) of PEE-PHPA was 21.5, 20.2, 7.30 and 37.1 µg/ml, and that of PEI25kD was 15.8, 18.3, 11.4 and 36.7 µg/ml in C6, COS-7, A549 and HEK293cell lines, respectively. The cell viability of PEI-CyD and PEI-PHPA in above cell lines was over 60%. They had high transfection efficiency in HEK293 cell lines. The LD(50) of PEI25Kd, PEI-CyD, PEI-PHPA and PEE-PHPA in vivo was 19.50, 100.4, 521.2 and 630.0, respectively by intraperitoneal (ip) injection. The contractions of these polymers were higher in kidney than in other organs and tissues.PEE-PHPA had slight effect on kidney and liver function. CONCLUSION: PEE and PEI25kD have higher transfection efficiency and higher toxicity; while PC and PHPA-PEI have lower toxicity and higher transfection efficiency to be used as non-viral gene vector.

[Modified montmorillonite as multifunction gene and drug delivery system].

OBJECTIVE: To develop polyethylenimine-Doxorubicin-montmorillonite (PEI-Dox-MTT) as a novel multifunction delivery system. METHODS: Dox was intercalated into montmorillonite, PEI covered to the surface of Dox/MMT to make the nano-particle. XRD, FT-IR and TGA were used to confirm chemical property of the nano-particle. SEM was used to observe the morphology. The capability of drug release was investigated by PBS buffer solution (pH 7.4). The DNA binding ability of nano-particle was detected by gel electrophoresis retardation assay. The cell viability in COS-7 and SKOV3 cell lines was tested using MTT assay. The gastric mucosa protection was evaluated in vitro. RESULTS: XRD image showed that Dox was intercalated into montmorillonite, inter space of which increased to 31.3Å; the FT-IR spectra showed the vibration bands of PEI at 1 560 cm(-1) and 2 850 cm(-1), the vibration band of Dox at 1 350 cm(-1). Size analysis and SEM revealed that the size of nano-particle was 600 nm, and the zeta-potential was 30 mV. Drug release experiment explored that the nano-particle stably released drug in range of 6 X10(-4) ≊ 8 X10(-4) mg/ml within 72 h. MTT assay showed that the cell viability was over 80% in experiment condition in COS-7 and SKOV3 cell lines. 0.3 mg PEI-MMT nano-particle was able to protect gastric mucosa from alcohol. CONCLUSION: Multifunction system of PEI/Dox/MMT has been prepared successfully.

Transparent Nanostructured BiVO4 Double Films with Blue Light Shielding Capabilities to Prevent Damage to ARPE-19 Cells.

The hazards posed by blue light to human eyes are attracting significant attention owing to increasing exposure to electronic devices as well as artificial illumination. Therefore, in this study, nanostructured BiVO4 (BVO) double films were developed using an economical and environmentally friendly sol-gel spin-coating method; the films exhibited excellent blue light shielding capabilities. They could block 65.25% of the blue light in the 415-455 nm wavelength range while simultaneously maintaining an average transmittance greater than 85% in the 500-800 nm wavelength range. Moreover, the damp heat test (85 °C, 85% relative humidity) showed the excellent stability of the BVO filters as their transmittances remained unchanged for 15 days. Importantly, cell experiments were performed to further confirm the protective effects of the BVO filters against the hazards posed by blue light to ARPE-19 cells (human retinal pigment epithelium cell line). Furthermore, the blue light weighted radiance LB decreased by 34.32%, and the color rendering index showed negligible differences after applying an upscaled BVO filter to a phone screen. These cost-efficient, ecofriendly, highly reliable, and large-area nanostructured BVO films with high blue light shielding efficiency have potential applications in various areas.

Distinct antibacterial activity of a vertically aligned graphene coating against Gram-positive and Gram-negative bacteria.

Graphene-based nanomaterials (GBNs) are known to exhibit biocidal activities, however, the combined effect of GBNs based on physical disruption and oxidative stress on different types of bacteria remain unclear. Here, we use both Gram-negative (Escherichia coli and Salmonella typhimurium) and Gram-positive (Staphylococcus aureus and Staphylococcus epidermidis) bacteria to investigate the antimicrobial properties of vertically and horizontally aligned graphenes grown on semiconductor silicon (Si) and insulator silicon dioxide (SiO2). It is found that the bacteria show different sensitivity to isomeric-structured GBNs. Gram-negative bacteria are more vulnerable to graphene-coated Si substrates than to SiO2, because the less negatively charged membrane enhances the electron transfer effect that extracts the electrons from the microbial membranes, and Gram-positive bacteria seem to show more susceptibility to physical puncturing of vertically aligned graphene than to horizontally aligned graphene due to the nature of the compound and the shape of the membrane structure. Subsequently, the vertically aligned graphene Si substrate (G@V-Si) exerts the superior antimicrobial ability on all the bacteria. Finally, all the above GBNs show low cytotoxicity and high biocompatibility, and the robust in vivo antibacterial effect indicates that G@V-Si could serve as an ideal platform for antimicrobial treatment.

[Aspirin-PEI-beta-CyD as a novel non-viral vector for gene transfer].

OBJECTIVE: To develop a novel non-viral gene delivery vector based on PEI-beta-CyD as backbone modified with aspirin, and to identify its physicochemical characters. METHODS: 1, 1-carbonyldiimidazole (CDI) was used to bind aspirin onto PEI-beta-CyD to form PEI-beta-CyD-ASP. (1)H-NMR, FT-IR, UV and XRD were used to confirm the polymer structure. The ability of condensation was demonstrated by gel retardation assay. MTT assay was used to test the cell viability in B16, Hela and A293 cell lines. Transfection efficiency of the polymer was tested in B16 cells. RESULT: The structure of PEI-beta-CyD-ASP was confirmed by (1)H-NMR, FT-IR, UV and XRD, which efficiently condensed plasmid DNA at the N/P ratio of 4. The copolymer showed low cytotoxicity and high transfection efficiency in B16 cells. CONCLUSION: The synthesized aspirin-PEI-beta-CyD might be a potential gene delivery vector.

[Peptide TAT modified polyethylenimine-beta-cyclodextrin for gene delivery].

OBJECTIVE: To develop a novel gene delivery vector TAT-PEI-beta-CyD. METHODS: beta-cyclodextrin (beta-CyD) was linked by low molecular weight (PEI 600) via 1, 1-carbonyldiimidazole (CDI), and TAT peptide (RRRQRRKKRC) was coupled to PEI 600 by [N-succinimidy-3-(2-pyridyldithio) propionate, SPDP]. The copolymer was characterized by (1)H-NMR and FT-IR. Physiochemical characteristics of TAT-PEI-beta-CyD/DNA complexes were tested by agarose gel electrophoresis and particle size measurements. Cell viability and transfection efficiency were evaluated in A293 and B16 cells using PEI 25 kDa as a control. RESULT: TAT peptide was successfully coupled to PEI-beta-CyD. The result of gel electrophoresis showed that the TAT-PEI-beta-CyD was able to condense DNA efficiently at N/P ratio of 4. The particle size of TAT-PEI-beta-CyD/DNA complexes was around 100 nm. The cytotoxicity of TAT-PEI-beta-CyD was lower than that of PEI 25 kDa. The transfection efficiency of TAT-PEI-beta-CyD was higher than that of PEI 25 kDa in A293 and B16 cells at N/P ratio of 30. CONCLUSION: The novel vector TAT-PEI-beta-CyD has been developed successfully with low cytotoxicity and high transfection efficiency.

[Peptide MC10 mediated PEI-beta-CyD as a gene delivery vector targeting to Her-2 receptor].

OBJECTIVE: To develop a novel non-viral gene delivery vector based on polyethylenimine and beta-cyclodextrin targeting to Her-2 receptor (MC10-PEI-beta-CyD). METHODS: The PEI-beta-CyD was synthesized by low molecular weight polyethylenimine (PEI, Mw 600) cross-linked beta-cyclodextrin (beta-CyD) via N, N-carbonyldiimidazole (CDI). The chemical linker[N-succinimidy-3-(2-pyridyldithio) propionate, SPDP] was used to bind peptide MC10 (MARAKEGGGC) to PEI-beta-CyD to form the vector MC10-PEI-beta-CyD. The (1)H-NMR was used to confirm the structure of vector. The DNA condensing ability,and the particle size of MC10-PEI-beta-CyD/DNA complexes were demonstrated by gel retardation assay and electron microscope observation (TEM). Cell viability was tested by MTT assay. The transfection efficiency was determined on cultured SKOV-3, A549 and MCF-7 cells. RESULT: MC10 was linked onto PEI-beta-CyD successfully. The vector was able to condense DNA at N/P ratio of 5 and particle size was about (170 +/-35)nm. The vector showed low cytotoxicity and high transfection efficiency in cultured SKOV-3, A549 and MCF-7 cells. CONCLUSION: A novel non-viral vector MC10-PEI-beta-CyD with low cytotoxicity and high transfection efficiency has been successfully synthesized.

[Preparation of floxuridine loaded polycation and its antitumor activity].

OBJECTIVE: To develop a new prodrug of 5-fluorouracil-polyethylenimine-beta-cyclodextrin-floxuridine (PEI-beta-CyD-Fd) and to test its antitumor activity. METHODS: Floxuridine was conjugated to polyethylenimine-beta-cyclodextrin to form prodrug PEI-beta-CyD-Fd. The structure of synthesized PEI-beta-CyD-Fd was confirmed by (1)H-NMR, FT-IR and UV. MTT assay and cell wound healing assay were performed on human hepatic carcinoma cell line HepG2. RESULT: The drug loading was 2 %. The MTT assay and cell wound healing assay indicated that PEI-beta-CyD-Fd significantly inhibited proliferation and migration of HepG2 cells. CONCLUSION: The synthesized prodrug PEI-CyD-Fd has a significant antitumor activity on HepG2 cells.