Mckenziezimmerman5634

The ongoing spread of multi-drug-resistant bacteria over the past few decades necessitates collateral efforts to develop new classes of antibacterial agents with different mechanisms of action. The utilization of graphene nanosheets has recently gained attention with this respect. Herein, we have synthesized and tested the antibacterial activity of an array of graphene materials covalently functionalized with hydroxyl-, amine-, or carboxyl-containing groups. Fourier transform infrared spectroscopy and transmission electron microscopy confirmed successful functionalization of the few-layer graphene (FLG). The percentage of weight loss was measured by thermogravimetric analysis, which was found to be 22%, 23%, and 37% for FLG-TEG-OH, FLG-NH2, and FLG-DEG-COOH, respectively. In comparison with pristine graphene sheets, the functionalized few-layer graphene (f-FLG) materials gained an adequate dispersibility in water as confirmed by ζ potential analysis. Moreover, there was a significant improvement in the antibacterial activity against Staphylococcus aureus and Escherichia coli, where all f-FLG compounds were able to suppress bacterial growth, with a complete suppression achieved by FLG-DEG-COOH. The minimum inhibitory concentration (MIC) was 250 μg mL-1 for both FLG-TEG-OH and FLG-NH2, while it was 125 μg mL-1 for FLG-DEG-COOH. The glutathione oxidation test demonstrated an oxidative stress activity by all f-FLG compounds. However, FLG-DEG-COOH demonstrated the highest reduction in glutathione activity. FLG-DEG-COOH and FLG-TEG-OH showed adequate biocompatibility and hemocompatibility. The chemical functionalization of graphene might be a step toward the foundation of an effective class of antimicrobial agents.The strategy of co-loading therapeutic agents in a single nanocarrier is the most common method in theranostic cancer research. However, it is still challenging to encapsulate theranostic agents that have different physicochemical properties in a single nanocarrier system because of the immiscibility between the hydrophobic fluorescent molecule and the hydrophilic drug molecule. Thus, we report a novel concept of a theranostic nanoparticle (NP) consisting of an amphiphilic near-infrared (NIR) dye as a hydrophilic drug delivery carrier with enhanced NIR imaging capability. Unlike conventional nanocarrier systems, the newly designed amphiphilic NIR dyes (Cy-C dyes) function as both the drug delivery carrier and the fluorescent imaging agent. It can be utilized for therapy and diagnosis simultaneously by simply encapsulating the hydrophilic drug. This method is innovative not only due to formation of the theranostic nanoparticle for immiscible hydrophilic drug delivery but also because of generation of strong flpt that the amphiphilic Cy-C9 dye is the best nanoplatform for theranostics based on hydrophilic drug delivery.Gene therapy is regarded as one of the most potential technologies for tumor therapy. Gene delivery systems with high specificity and good biocompatibility are urgently demanded. Hence, in this research, we designed and synthesized a series of tumor targeting and redox-responsive gold nanoparticles conjugated with three kinds of functional polypeptides (AuNPPs) that consisted of targeting peptide GE11, cell-penetrating peptide octaarginine (R8), and polyhistidine. All the AuNPPs exhibited superior cancer cellular internalization ability and targeting gene transfection efficiency compared with commercial agent BPEI 25K. It is interesting to find that different relative positions of GE11 and R8 can cause the change of target ability and gene transfection efficiency, and the suitable relative position of R8 and GE11 can not only endow the gene vector with functions that peptides previously own but also bring the synergistic effects. The best-performed AuNPP6-1 was chosen to transport the epidermal growth factor receptor (EGFR)-shRNA into A549 tumor-bearing BALB/c nude mice, and in vivo fluorescence imaging showed AuNPP6-1 mainly accumulated in tumor sites and achieved a great targeting therapy effect. These results provide significantly important information on understanding and constructing the tumor-targeting gene vector.A major obstacle for topical and enteral drug delivery is the poor transport of macromolecular drugs through the epithelium. One potential solution is the use of permeation enhancers that alter epithelial structures. Piperazine derivatives are known permeation enhancers that modulate epithelial structures, reduce transepithelial electrical resistance, and augment the absorption of macromolecular drugs. The mechanism by which piperazine derivatives disrupt the structures of epithelial monolayers is not well understood. Here, the effects of 1-phenylpiperazine and 1-methyl-4-phenylpiperazine are modeled in the epithelial cell line NRK-52E. read more Live-cell imaging reveals a dose-dependent gross reorganization of monolayers at high concentrations, but reorganization differs based on the piperazine molecule. Results show that low concentrations of piperazine derivatives increase myosin force generation within the cells and do not disrupt the cytoskeletal structure. Also, cytoskeletally attached cadherin junctions are disrupted before tight junctions. In summary, piperazines appear to increase myosin-mediated contraction followed by disruption of cell-cell contacts. These results provide new mechanistic insight into how transient epithelial permeation enhancers act and will inform of the development of future generations of transepithelial delivery systems.Three-dimensional honeycomb porous carbon (HPC) has attracted increasing attention in bioengineering due to excellent mechanical properties and a high surface-to-volume ratio. In this paper, a three-dimensional chitosan (CS)/honeycomb porous carbon/hydroxyapatite composite was prepared by nano-sized hydroxyapatite (nHA) on the HPC surface in situ deposition, dissolved in chitosan solution, and vacuum freeze-dried. The structure and composition of CS/HPC/nHA were characterized by scanning electron microscopy, transmission electron miscroscopy, Fourier transform infrared, and X-ray photoelectron spectroscopy, and the porosity, swelling ratio, and mechanical properties of the scaffold were also tested. The as-prepared scaffolds possess hierarchical pores and organic-inorganic components, which are similar in composition and structure to bone tissues. The synthesized composite scaffold has high porosity and a certain mechanical strength. By culturing mouse bone marrow mesenchymal stem cells on the surface of the scaffold, it was confirmed that the scaffold facilitated its growth and promoted its differentiation into the osteogenesis direction.