Cheng Sui | University of Nottingham (original) (raw)

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Papers by Cheng Sui

Research paper thumbnail of Preparation, characterization and pharmacological evaluation of tolterodine hydrogels for the treatment of overactive bladder

International journal of pharmaceutics, Jan 15, 2013

In this study, transdermal gel formulations for tolterodine were developed to investigate the eff... more In this study, transdermal gel formulations for tolterodine were developed to investigate the effects of gel matrix and chemical enhancers on drug skin permeation from tolterodine hydrogels. In vitro permeation studies of tolterodine through excised mouse skin were carried out using Franz-type diffusion cells. In the optimum gel formulation, Carbopol 940 was selected as the gel matrix. Compared to gels without enhancer, tolterodine hydrogels with N-methyl pyrrolidone (NMP) showed significant enhancing effect on transdermal permeation of tolterodine (p<0.05). The results of in vitro percutaneous delivery experiment showed that the relationship of the steady accumulative percutaneous amount (Q, μg cm(-2)) of tolterodine hydrogels and time was Q4-12h=770.19t(1/2)-966.99. Tolterodine permeated at the steady-state speed of 770.19 μg cm(-2)h(-1) and its release coincided with Higuchi Equation. The pharmacokinetic properties of the optimized tolterodine formulation were studied in rabbi...

Research paper thumbnail of Studies on the preparation, characterization and pharmacological evaluation of tolterodine PLGA microspheres

International Journal of Pharmaceutics, 2010

l-tartrate tablets. There were invisible changes in rat bladder slices between tolterodine-loaded... more l-tartrate tablets. There were invisible changes in rat bladder slices between tolterodine-loaded PLGA microspheres group and tolterodine l-tartrate tablets group. These results indicate that the continuous inhibition of muscarinic receptor may offer an alternative therapy of urge incontinence.

Research paper thumbnail of Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

Nature Materials, 2014

The detection and inactivation of pathogenic strains of bacteria continues to be an important the... more The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms, for diagnostic or anti-infective applications, but which can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerisation of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms which produced them. This 'bacteriainstructed synthesis' can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the 'instructing' cell types. We further expand on the bacterial redox chemistries to 'click' fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualisation of pathogens.

Research paper thumbnail of Bacteria clustering by polymers induces the expression of quorum-sensing-controlled phenotypes

Nature Chemistry, 2013

Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environme... more Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environment. Quorum sensing is one mean by which bacteria use chemical reactions to modulate pre-infection behaviour such as surface attachment. Polymers that can interfere with bacterial adhesion or the chemical reactions used for quorum sensing are thus a potential means to control bacterial population responses. Here we report how polymeric "bacteria sequestrants", designed to bind to bacteria through electrostatic interactions and thus inhibit bacterial adhesion to surfaces, induce the expression of quorum sensing controlled phenotypes as a consequence of cell clustering. A combination of polymer and analytical chemistry, biological assays and computational modelling has been used to characterise the feedback between bacteria clustering and quorum sensing signaling. We have also derived design principles and chemical strategies for controlling bacterial behaviour at the population level.

Research paper thumbnail of Preparation, characterization and pharmacological evaluation of tolterodine hydrogels for the treatment of overactive bladder

International journal of pharmaceutics, Jan 15, 2013

In this study, transdermal gel formulations for tolterodine were developed to investigate the eff... more In this study, transdermal gel formulations for tolterodine were developed to investigate the effects of gel matrix and chemical enhancers on drug skin permeation from tolterodine hydrogels. In vitro permeation studies of tolterodine through excised mouse skin were carried out using Franz-type diffusion cells. In the optimum gel formulation, Carbopol 940 was selected as the gel matrix. Compared to gels without enhancer, tolterodine hydrogels with N-methyl pyrrolidone (NMP) showed significant enhancing effect on transdermal permeation of tolterodine (p<0.05). The results of in vitro percutaneous delivery experiment showed that the relationship of the steady accumulative percutaneous amount (Q, μg cm(-2)) of tolterodine hydrogels and time was Q4-12h=770.19t(1/2)-966.99. Tolterodine permeated at the steady-state speed of 770.19 μg cm(-2)h(-1) and its release coincided with Higuchi Equation. The pharmacokinetic properties of the optimized tolterodine formulation were studied in rabbi...

Research paper thumbnail of Studies on the preparation, characterization and pharmacological evaluation of tolterodine PLGA microspheres

International Journal of Pharmaceutics, 2010

l-tartrate tablets. There were invisible changes in rat bladder slices between tolterodine-loaded... more l-tartrate tablets. There were invisible changes in rat bladder slices between tolterodine-loaded PLGA microspheres group and tolterodine l-tartrate tablets group. These results indicate that the continuous inhibition of muscarinic receptor may offer an alternative therapy of urge incontinence.

Research paper thumbnail of Bacteria-instructed synthesis of polymers for self-selective microbial binding and labelling

Nature Materials, 2014

The detection and inactivation of pathogenic strains of bacteria continues to be an important the... more The detection and inactivation of pathogenic strains of bacteria continues to be an important therapeutic goal. Hence, there is a need for materials that can bind selectively to specific microorganisms, for diagnostic or anti-infective applications, but which can be formed from simple and inexpensive building blocks. Here, we exploit bacterial redox systems to induce a copper-mediated radical polymerisation of synthetic monomers at cell surfaces, generating polymers in situ that bind strongly to the microorganisms which produced them. This 'bacteriainstructed synthesis' can be carried out with a variety of microbial strains, and we show that the polymers produced are self-selective binding agents for the 'instructing' cell types. We further expand on the bacterial redox chemistries to 'click' fluorescent reporters onto polymers directly at the surfaces of a range of clinical isolate strains, allowing rapid, facile and simultaneous binding and visualisation of pathogens.

Research paper thumbnail of Bacteria clustering by polymers induces the expression of quorum-sensing-controlled phenotypes

Nature Chemistry, 2013

Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environme... more Bacteria deploy a range of chemistries to regulate their behaviour and respond to their environment. Quorum sensing is one mean by which bacteria use chemical reactions to modulate pre-infection behaviour such as surface attachment. Polymers that can interfere with bacterial adhesion or the chemical reactions used for quorum sensing are thus a potential means to control bacterial population responses. Here we report how polymeric "bacteria sequestrants", designed to bind to bacteria through electrostatic interactions and thus inhibit bacterial adhesion to surfaces, induce the expression of quorum sensing controlled phenotypes as a consequence of cell clustering. A combination of polymer and analytical chemistry, biological assays and computational modelling has been used to characterise the feedback between bacteria clustering and quorum sensing signaling. We have also derived design principles and chemical strategies for controlling bacterial behaviour at the population level.

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