Donut-like MOFs of copper/nicotinic acid and composite hydrogels with superior bioactivity for rh-bFGF delivering and skin wound healing.

BACKGROUND: Skin injury and the resultant defects are common clinical problems, and usually lead to chronic skin ulcers and even life-threatening diseases. Copper, an essential trace element of human body, has been reported to promote the regeneration of skin by stimulating proliferation of endothelial cell and enhance angiogenesis. RESULTS: Herein, we have prepared a new donut-like metal-organic frameworks (MOF) of copper-nicotinic acid (CuNA) by a simple solvothermal reaction. The rough surface of CuNA is beneficial for loading/release basic fibroblast growth factor (bFGF). The CuNAs with/without bFGF are easily processed into a light-responsive composite hydrogel with GelMA, which not only show excellent mechanical properties, but also display superior biocompatibility, antibacterial ability and bioactivity. Moreover, in the in vivo full-thickness defect model of skin wound, the resultant CuNA-bFGF@GelMA hydrogels significantly accelerate the wound healing, by simultaneously inhibiting the inflammatory response, promoting the new blood vessels formation and the deposition of collagen and elastic fibers. CONCLUSIONS: Considering the superior biocompatibility, antibacterial ability and bioactivity, the CuNA and its composite light-responsive hydrogel system will be promising in the applications of skin and even other tissue regeneration.

Dendritic poly(L-lysine)-b-Poly(L-lactide)-b-dendritic poly(L-lysine) amphiphilic gene delivery vectors: roles of PLL dendritic generation and enhanced transgene efficacies via termini modification.

As an effort to prepare new efficient gene delivery vectors, we have recently developed and reported an amphiphilic dendritic poly(L-lysine)-b-poly(L-lactide)-b-dendritic poly(L-lysine) D(2)-PLLA-D(2) with two-generation PLL dendrons and a PLLA block. In this work, we continued to explore the roles of dendritic PLL generation in DNA binding and intracellular delivery of gene, and a new series of amphiphilic dendritic poly(L-lysine)-b-poly(L-lactide)-b-dendritic poly(L-lysine)s D(n)-PLLA-D(n) (n = 3-5) were synthesized and were structurally characterized. Furthermore, plasmid DNA binding affinity for these cationic amphiphiles was examined by agarose gel electrophoresis and fluorescence titration assay in pure water and PBS buffer solution containing 150 mM NaCl (pH = 7.4), respectively. By dynamic light scattering (DLS) and transmission electronic microscopy (TEM), the interaction and complexation in between were investigated, concerning the DNA/vector polyplex particle morphologies and zeta potentials. Utilizing a human hepatocellular carcinoma cell-line SMMC-7721, cell toxicity, and gene transfection in vitro were explored. To further improve transgene efficiency for these synthetic cationic amphiphiles as gene delivery vectors, new structural DE(n)-PLLA-DE(n) (n = 2-3) were prepared through an amino termini modification of the D(n)-PLLA-D(n) (n = 2-3) with less toxic 4,7,10,13-tetraazatridecanoic acids, and gene transfection with these DE(n)-PLLA-DE(n) (n = 2-3) was examined with an alternative human gastric carcinoma cell-line HGC-27. As a result, the high plasmid DNA binding affinity, low cytotoxicity, and much enhanced transgene efficacy suggest a new possible clue to design effective synthetic gene delivery vectors with amphiphilic skeleton and less toxic polyamine building blocks.

Comparison of six digestion methods on fluorescent intensity and morphology of the fluorescent polystyrene beads.

Effect of digestion methods on fluorescence intensity of fluorescent polystyrene (PS) beads was poorly understood, which may affect the accuracy of toxicity test of the fluorescent PS beads exposed to marine organisms. Therefore, six digestion approaches were compared on fluorescence intensities and properties of three commercial fluorescent PS beads. Among all the protocols, the digestion using KOH (10% w/v, 60 °C) (KOH-digestion) had no effect on the fluorescence intensity, morphology and composition of the three fluorescent PS beads. Moreover, the extraction efficiency ≥ 95.3 ±â€¯0.2% of fluorescent PS beads in Daphnia magna and zebrafish, confirming its feasibility in fluorescent PS beads quantitative analysis. However, the fluorescence intensities of fluorescent PS beads digested by other five protocols were significantly decreased, as well as the change of morphology and composition on fluorescent PS beads. Overall, the KOH-digestion is an optimal protocol for extracting fluorescent PS beads in biological samples.

Preparation of new amphiphilic macroporous nonwoven polymeric adsorbents aimed for selective removal of low-density lipoprotein from plasma.

In the present work, new amphiphilic macroporous polymeric adsorbent (AMPA) membranes for LDL-apheresis were prepared by (60)Co γ-ray irradiation-induced grafting copolymerization of polypropylene (PP) nonwoven fabric with acrylic acid, followed by bonding cholesterol through linkers of different length. The new AMPA membranes were characterized by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy, scanning electron microscope (SEM), and contact angle microscopy. Static adsorption and hemo-perfusion tests show these new adsorbents could efficiently remove LDL from human plasma. Meanwhile, the AMPA displayed good adsorption capacity for triglyceride (TG) as well. The static adsorption performance of the AMPA membranes depends on the length of linker. In addition, a balance between the amount of bonded cholesterol and remaining carboxyl group was found necessary to reach the optimal adsorption performance. The best result was achieved by the AMPA membrane PA15C6-3, by which 62.8 ± 3.8 µg of LDL-C, 16.5 ± 0.71 µg of HDL-C, 132.4 ± 3.0 µg of TG are removed from human plasma per square centimeter.

New preparation of structurally symmetric, biodegradable poly(L-lactide) disulfides and PLLA-stabilized, photoluminescent CdSe quantum dots.

New, biodegradable poly(L-lactide) disulfides, PLLA-SS-PLLA, were first prepared through the DMAP-catalyzed ring-opening polymerization of L-lactide with a dihydroxyethyl disulfide initiator, and were further catalytically reduced into thiol-end-functionalized poly(L-lactide)s, HO-PLLA-SH, with a tributyl phosphine catalyst (PBu3). Employing the HO-PLLA-SH as the ligand, new core-shell CdSe/PLLA quantum dots (QDs) were continuously prepared via a facile ligand-exchanging process with the CdSe/TOPO QD precursor. The chemical structures, morphologies and solvent solubility of these prepared CdSe/PLLA QDs were investigated by NMR spectroscopy, FTIR spectroscopy, XRD, TEM and excitation under either room light or UV radiation at 365 nm, demonstrating the successful ligand replacement and the new formation of core-shell CdSe/PLLA QDs (diameter:4.0 +/- 0.3 nm). Finally, UV and FL results indicate the two factors of the HO-PLLA-SH ligand molecular weight and the ligand/QD precursor feeding weight ratio were important for preparing stable and highly photoluminescent CdSe/PLLA QDs.

Photothermal switch by gallic acid-calcium grafts synthesized by coordination chemistry for sequential treatment of bone tumor and regeneration.

The residual bone tumor and defects which is caused by surgical therapy of bone tumor is a major and important problem in clinicals. And the sequential treatment for irradiating residual tumor and repairing bone defects has wildly prospects. In this study, we developed a general modification strategy by gallic acid (GA)-assisted coordination chemistry to prepare black calcium-based materials, which combines the sequential photothermal therapy of bone tumor and bone defects. The GA modification endows the materials remarkable photothermal properties. Under the near-infrared (NIR) irradiation with different power densities, the black GA-modified bone matrix (GBM) did not merely display an excellent performance in eliminating bone tumor with high temperature, but showed a facile effect of the mild-heat stimulation to accelerate bone regeneration. GBM can efficiently regulate the microenvironments of bone regeneration in a spatial-temporal manner, including inflammation/immune response, vascularization and osteogenic differentiation. Meanwhile, the integrin/PI3K/Akt signaling pathway of bone marrow mesenchymal stem cells (BMSCs) was revealed to be involved in the effect of osteogenesis induced by the mild-heat stimulation. The outcome of this study not only provides a serial of new multifunctional biomaterials, but also demonstrates a general strategy for designing novel blacked calcium-based biomaterials with great potential for clinical use.