Co-reporter:Ting Wei, Zengchao Tang, Qian Yu, and Hong Chen
ACS Applied Materials & Interfaces November 1, 2017 Volume 9(Issue 43) pp:37511-37511
Publication Date(Web):October 9, 2017
DOI:10.1021/acsami.7b13565
The attachment and subsequent colonization of bacteria on the surfaces of synthetic materials and devices lead to serious problems in both human healthcare and industrial applications. Therefore, antibacterial surfaces that can prevent bacterial attachment and biofilm formation have been a long-standing focus of considerable interest and research efforts. Recently, a promising “kill–release” strategy has been proposed and applied to construct so-called smart antibacterial surfaces, which can kill bacteria attached to their surface and then undergo on-demand release of the dead bacteria and other debris to reveal a clean surface under an appropriate stimulus, thereby maintaining effective long-term antibacterial activity. This Review focuses on the recent progress (particularly over the past 5 years) on such smart antibacterial surfaces. According to the different design strategies, these surfaces can be divided into three categories: (i) “K + R”-type surfaces, which have both a killing unit and a releasing unit; (ii) “K → R”-type surfaces, which have a surface-immobilized killing unit that can be switched to perform a releasing function; and (iii) “K + (R)”-type surfaces, which have only a killing unit but can release dead bacteria upon the addition of a release solution. In the end, a brief perspective on future research directions and the major challenges in this promising field is also presented.Keywords: antibacterial surface; bacterial release; bactericidal surface; kill−release strategy; stimuli-responsive polymer;
Co-reporter:Jingxian Wu, Hui Xue, Zhonglin Lyu, Zhenhua Li, Yangcui Qu, Yajun Xu, Lei Wang, Qian Yu, and Hong Chen
ACS Applied Materials & Interfaces July 5, 2017 Volume 9(Issue 26) pp:21593-21593
Publication Date(Web):June 20, 2017
DOI:10.1021/acsami.7b06201
The intracellular delivery of exogenous macromolecules is of great interest for both fundamental biological research and clinical applications. Although traditional delivery systems based on either carrier mediation or membrane disruption have some advantages; however, they are generally limited with respect to delivery efficiency and cytotoxicity. Herein, a collaborative intracellular delivery platform with excellent comprehensive performance is developed using polyethylenimine of low molecular weight (LPEI) as a gene carrier in conjunction with a gold nanoparticle layer (GNPL) acting as a photoporation agent. In this system, the LPEI protects the plasmid DNA (pDNA) to avoid possible nuclease degradation, and the GNPL improves the delivery efficiency of the LPEI/pDNA complex to the cells. The collaboration of LPEI and GNPL is shown to give significantly higher transfection efficiencies for hard-to-transfect cells (88.5 ± 9.2% for mouse embryonic fibroblasts, 94.0 ± 6.3% for human umbilical vein endothelial cells) compared to existing techniques without compromising cell viability.Keywords: gene transfection; gold nanoparticle layer; intracellular delivery; photoporation; polyethylenimine;
Co-reporter:Ting Wei, Wenjun Zhan, Qian Yu, and Hong Chen
ACS Applied Materials & Interfaces August 9, 2017 Volume 9(Issue 31) pp:25767-25767
Publication Date(Web):July 20, 2017
DOI:10.1021/acsami.7b06483
Smart biointerfaces with capability to regulate cell–surface interactions in response to external stimuli are of great interest for both fundamental research and practical applications. Smart surfaces with “ON/OFF” switchability for a single function such as cell attachment/detachment are well-known and useful, but the ability to switch between two different functions may be seen as the next level of “smart”. In this work reported, a smart supramolecular surface capable of switching functions reversibly between bactericidal activity and bacteria-releasing ability in response to UV–visible light is developed. This platform is composed of surface-containing azobenzene (Azo) groups and a biocidal β-cyclodextrin derivative conjugated with seven quaternary ammonium salt groups (CD-QAS). The surface-immobilized Azo groups in trans form can specially incorporate CD-QAS to achieve a strongly bactericidal surface that kill more than 90% attached bacteria. On irradiation with UV light, the Azo groups switch to cis form, resulting in the dissociation of the Azo/CD-QAS inclusion complex and release of dead bacteria from the surface. After the kill-and-release cycle, the surface can be easily regenerated for reuse by irradiation with visible light and reincorporation of fresh CD-QAS. The use of supramolecular chemistry represents a promising approach to the realization of smart, multifunctional surfaces, and has the potential to be applied to diverse materials and devices in the biomedical field.Keywords: antibacterial surface; bacterial release; dynamic biointerface; host−guest interaction; photoresponsive;
Co-reporter:Ting Wei, Yanyan Zhou, Wenjun Zhan, Zhengbiao Zhang, Xiulin Zhu, Qian Yu, Hong Chen
Colloids and Surfaces B: Biointerfaces 2017 Volume 159(Volume 159) pp:
Publication Date(Web):1 November 2017
DOI:10.1016/j.colsurfb.2017.08.021
•Surfaces modified with cyclic polymers and linear polymers were prepared.•The topological effect of cyclic polymers led to the formation of denser brushes.•Density difference led to different protein adsorption trends with protein size.•No topological effect was observed for cell-surface interactions.Cyclic polymers, having no chain ends, are in contrast to their linear counterparts with respect to topology and related properties. While the behavior of cyclic polymers in solution is well investigated, there is little information on the effects of cyclic chain topology on surfaces grafted with these polymers. In particular, the effects of topology on the interactions of such surfaces with biological systems are unknown. In this work, we prepared gold surfaces modified with either cyclic or linear polystyrene (CPS, LPS) using a grafting-to strategy, and used these surfaces to investigate the effects of chain topology on their biointerfacial interactions. It was shown that compared to LPS with similar molecular weight, the smaller hydrodynamic radius of CPS leads to brushes of higher chain density, and that the higher chain density facilitates the adsorption of larger proteins but suppresses the adsorption of smaller ones. However, no significant differences in bacterial attachment or mammalian cell proliferation between CPS and LPS brushes were found, indicating that topological effects are absent for the larger entities.Download high-res image (211KB)Download full-size image
Co-reporter:Wenjun Zhan, Ting Wei, Limin Cao, Changming Hu, Yangcui Qu, Qian YuHong Chen
ACS Applied Materials & Interfaces 2017 Volume 9(Issue 4) pp:
Publication Date(Web):January 10, 2017
DOI:10.1021/acsami.6b15446
Surfaces having dynamic control of interactions at the biological system–material interface are of great scientific and technological interest. In this work, a supramolecular platform with switchable multivalent affinity was developed to efficiently capture bacteria and on-demand release captured bacteria in response to irradiation with light of different wavelengths. The system consists of a photoresponsive self-assembled monolayer containing azobenzene (Azo) groups as guest and β-cyclodextrin (β-CD)-mannose (CD-M) conjugates as host with each CD-M containing seven mannose units to display localized multivalent carbohydrates. Taking the advantage of multivalent effect of CD-M, this system exhibited high capacity and specificity for the capture of mannose-specific type 1-fimbriated bacteria. Moreover, ultraviolet (UV) light irradiation caused isomerization of the Azo groups from trans-form to cis-form, resulting in the dissociation of the host–guest Azo/CD-M inclusion complexes and localized release of the captured bacteria. The capture and release process could be repeated for multiple cycles, suggesting good reproducibility. This platform provides the basis for development of reusable biosensors and diagnostic devices for the detection and measurement of bacteria and exhibits great potential for use as a standard protocol for the on-demand switching of surface functionalities.Keywords: bacterial capture; bacterial release; host−guest interaction; multivalent effect; Photoresponsive;
Co-reporter:Zhonglin Lyu;Xiujuan Shi;Jiehua Lei;Yuqi Yuan;Lin Yuan;Hong Chen
Journal of Materials Chemistry B 2017 vol. 5(Issue 10) pp:1896-1900
Publication Date(Web):2017/03/08
DOI:10.1039/C6TB02572B
A heparin-mimicking biomolecule, β-cyclodextrin decorated with sulfonate groups (CD-S), was synthesized. CD-S itself exhibited bioactivity similar to that of heparin and can further serve as a carrier for all-trans retinoic acid by forming inclusion complexes that promote neural differentiation of embryonic stem cells more effectively than heparin.
Co-reporter:Yangcui Qu;Ting Wei;Wenjun Zhan;Changming Hu;Limin Cao;Hong Chen
Journal of Materials Chemistry B 2017 vol. 5(Issue 3) pp:444-453
Publication Date(Web):2017/01/18
DOI:10.1039/C6TB02821G
In this work, a reusable supramolecular platform for the specific capture and release of proteins and bacteria was developed. Multilayered polyelectrolyte films containing “guest” moieties were first fabricated using the layer-by-layer (LbL) deposition of poly(allylamine hydrochloride) and poly(acrylic acid-co-1-adamantan-1-ylmethyl acrylate), followed by the incorporation of β-cyclodextrin (β-CD) derivatives modified with mannose (CD-M) as “host” molecules with protein (lectin) binding properties. This platform combines three different non-covalent interactions: electrostatic interactions for the LbL deposition of multilayered films, host–guest inclusion for the incorporation of β-CD-conjugated ligands, and carbohydrate–protein affinity recognition for the capture of specific proteins and bacteria. For the mannose system investigated, the capture of Concanavalin A (ConA) and type I fimbriated Escherichia coli was demonstrated. Moreover, due to the inherent reversibility of host–guest interactions, the captured proteins and bacteria could be easily released from the surface by incubation with sodium dodecyl sulfate, and the renewed “guest” surface could be treated with the CD-M “host” to regenerate the ConA and E. coli-binding surface. This “use-regenerate” cycle could be repeated multiple times without significant loss of bioactivity. Given the generality and versatility of this approach, it may provide the basis for the development of re-usable biosensors and diagnostic devices for the detection and measurement of proteins and bacteria.
Co-reporter:Zhonglin Lyu;Feng Zhou;Qi Liu;Hui Xue;Hong Chen
Advanced Functional Materials 2016 Volume 26( Issue 32) pp:5787-5795
Publication Date(Web):
DOI:10.1002/adfm.201602036
Although promising, it is challenging to develop a simple and universal method for the high-efficiency delivery of biomacromolecules into diverse cells. Here, a universal delivery platform based on gold nanoparticle layer (GNPL) surfaces is proposed. Upon laser irradiation, GNPL surfaces show such good photothermal properties that absorption of the laser energy causes a rapid increase in surface temperature, leading to enhanced membrane permeability of the cultured cells and the diffusion of macromolecules into the cytosol from the surrounding medium. The high-efficiency delivery of different macromolecules such as dextran and plasmid DNA into different cell types is achieved, including hard-to-transfect mouse embryonic fibroblasts (mEFs) and human umbilical vein endothelial cells (HUVECs), while cell viability is well maintained under optimized irradiation conditions. The platform vastly outperforms the leading commercial reagent, Lipofectamine 2000, especially in transfecting hard-to-transfect cell lines (plasmid transfection efficiency: ≈53% vs ≈19% for mEFs and ≈44% vs ≈8% for HUVECs). Importantly, as the gold nanoparticles (GNPs) constituting the GNPL are firmly immobilized together, the potential cytotoxicity caused by endocytosis of GNPs is effectively avoided. This platform is reliable, efficient, and cost-effective with high-throughput and broad applicability across different cell types, opening up an innovative avenue for high-efficiency intracellular delivery.
Co-reporter:Ting Wei, Wenjun Zhan, Limin Cao, Changming Hu, Yangcui Qu, Qian Yu, and Hong Chen
ACS Applied Materials & Interfaces 2016 Volume 8(Issue 44) pp:30048
Publication Date(Web):October 19, 2016
DOI:10.1021/acsami.6b11187
Development of a versatile strategy for antibacterial surfaces is of great scientific interest and practical significance. However, few methods can be used to fabricate antibacterial surfaces on substrates of different chemistries and structures. In addition, traditional antibacterial surfaces may suffer problems related to the attached dead bacteria. Herein, antibacterial surfaces with multifunctionality and regenerability are fabricated by a universal strategy. Various substrates are first deposited with multilayered films containing guest moieties, which can be further used to incorporate biocidal host molecules, β-cyclodextrin (β-CD) derivatives modified with quaternary ammonium salt groups (CD-QAS). The resulting surfaces exhibit strong biocidal activity to kill more than 95% of attached pathogenic bacteria. Notably, almost all the dead bacteria can be easily removed from the surfaces by simple immersion in sodium dodecyl sulfate, and the regenerated surfaces can be treated with new CD-QAS for continued use. Moreover, when another functional β-CD derivative molecule is co-incorporated together with CD-QAS, the surfaces exhibit both functions simultaneously, and neither specific biofunction and antibacterial activity is compromised by the presence of the other. These results thus present a promising way to fabricate multifunctional and regenerable antibacterial surfaces on diverse materials and devices in the biomedical fields.Keywords: antibacterial surface; host−guest interaction; layer-by-layer assembly; multifunctionality; regenerability
Co-reporter:Ting Wei;Wenjun Zhan ;Hong Chen
Advanced Healthcare Materials 2016 Volume 5( Issue 4) pp:449-456
Publication Date(Web):
DOI:10.1002/adhm.201500700
For various human healthcare and industrial applications, endowing surfaces with the capability to not only efficiently kill bacteria but also release dead bacteria in a rapid and repeatable fashion is a promising but challenging effort. In this work, the synergistic effects of combining stimuli-responsive polymers and nanomaterials with unique topographies to achieve smart antibacterial surfaces with on-demand switchable functionalities are explored. Silicon nanowire arrays are modified with a pH-responsive polymer, poly(methacrylic acid), which serves as both a dynamic reservoir for the controllable loading and release of a natural antimicrobial lysozyme and a self-cleaning platform for the release of dead bacteria and the reloading of new lysozyme for repeatable applications. The functionality of the surface can be simply switched via step-wise modification of the environmental pH and can be effectively maintained after several kill–release cycles. These results offer a new methodology for the engineering of surfaces with switchable functionalities for a variety of practical applications in the biomedical and biotechnology fields.
Co-reporter:Wenjun Zhan;Xiujuan Shi;Zhonglin Lyu;Limin Cao;Hui Du;Qi Liu;Xin Wang;Gaojian Chen;Dan Li;John L. Brash;Hong Chen
Advanced Functional Materials 2015 Volume 25( Issue 32) pp:5206-5213
Publication Date(Web):
DOI:10.1002/adfm.201501642
Developing surfaces with antithrombotic properties is of great interest for the applications of blood-contacting biomaterials and medical devices. It is promising to coimmobilize two or more biomolecules with different and complementary functions to improve blood compatibility. However, the general one-pot strategy usually adopted by previous studies suffers the problems of inevitable competition between diverse biomolecules and uncontrollability of the relative quantities of the immobilized biomolecules. To solve these problems, a new sequential coimmobilization strategy is proposed and applied to fabricate a blood compatible surface. Polyurethane surface is modified with a copolymer, poly(2-hydroxyethyl methacrylate-co-1-adamantan-1-ylmethyl methacrylate), which serves as a linker-spacer for sequential attachment of two functional molecules, a hexapeptide containing REDV (Arg-Glu-Asp-Val) sequence, and a modified cyclodextrin bearing 7 lysine ligands, through covalent bonding and host–guest interaction, respectively. The resulting surface combines the antithrombogenic properties of the vascular endothelium and the clot lysing properties of the fibrinolytic system. Importantly, neither of the two functions of REDV peptide and lysine is compromised by the presence of the other, suggesting the enhanced blood compatibility. These results suggest a new strategy to engineer multifunctional surfaces by coimmobilization of bioactive molecules having unique functionalities.
Co-reporter:Changming Hu, Yangcui Qu, Wenjun Zhan, Ting Wei, Limin Cao, Qian Yu, Hong Chen
Colloids and Surfaces B: Biointerfaces (1 April 2017) Volume 152() pp:
Publication Date(Web):1 April 2017
DOI:10.1016/j.colsurfb.2017.01.025
•Bioactive surfaces were fabricated via LbL assembly and host-guest interaction.•The biotin-avidin system was used as a model system in binding studies.•The surface exhibited a high capacity and selectivity for avidin binding.•Surface regeneration could be realized by treatment with SDS.Bioactive surfaces with immobilized bioactive molecules aimed specifically at promoting or supporting particular interactions are of great interest for application of biosensors and biological detection. In this work, we fabricated a supramolecular bioactive surface with specific protein binding capability using two noncovalent interactions as the driving forces. The substrates were first layer-by-layer (LbL) deposited with a multilayered polyelectrolyte film containing “guest” adamantane groups via electrostatic interactions, followed by incorporation of “host” β-cyclodextrin derivatives bearing seven biotin units (CD-B) into the films via host-guest interactions. The results of fluorescence microscopy and quartz crystal microbalance measurement demonstrated that these surfaces exhibited high binding capacity and high selectivity for avidin due to the high density of biotin residues. Moreover, since host-guest interactions are inherently reversible, the avidin-CD-B complex is easily released by treatment with the sodium dodecyl sulfate, and the “regenerated” surfaces, after re-introducing fresh CD-B, can be used repeatedly for avidin binding. Given the generality and versatility of this approach, it may pave a way for development of re-usable biosensors for the detection and measurement of specific proteins.
Co-reporter:Zhonglin Lyu, Xiujuan Shi, Jiehua Lei, Yuqi Yuan, Lin Yuan, Qian Yu and Hong Chen
Journal of Materials Chemistry A 2017 - vol. 5(Issue 10) pp:NaN1900-1900
Publication Date(Web):2017/02/13
DOI:10.1039/C6TB02572B
A heparin-mimicking biomolecule, β-cyclodextrin decorated with sulfonate groups (CD-S), was synthesized. CD-S itself exhibited bioactivity similar to that of heparin and can further serve as a carrier for all-trans retinoic acid by forming inclusion complexes that promote neural differentiation of embryonic stem cells more effectively than heparin.
Co-reporter:Yangcui Qu, Ting Wei, Wenjun Zhan, Changming Hu, Limin Cao, Qian Yu and Hong Chen
Journal of Materials Chemistry A 2017 - vol. 5(Issue 3) pp:NaN453-453
Publication Date(Web):2016/12/05
DOI:10.1039/C6TB02821G
In this work, a reusable supramolecular platform for the specific capture and release of proteins and bacteria was developed. Multilayered polyelectrolyte films containing “guest” moieties were first fabricated using the layer-by-layer (LbL) deposition of poly(allylamine hydrochloride) and poly(acrylic acid-co-1-adamantan-1-ylmethyl acrylate), followed by the incorporation of β-cyclodextrin (β-CD) derivatives modified with mannose (CD-M) as “host” molecules with protein (lectin) binding properties. This platform combines three different non-covalent interactions: electrostatic interactions for the LbL deposition of multilayered films, host–guest inclusion for the incorporation of β-CD-conjugated ligands, and carbohydrate–protein affinity recognition for the capture of specific proteins and bacteria. For the mannose system investigated, the capture of Concanavalin A (ConA) and type I fimbriated Escherichia coli was demonstrated. Moreover, due to the inherent reversibility of host–guest interactions, the captured proteins and bacteria could be easily released from the surface by incubation with sodium dodecyl sulfate, and the renewed “guest” surface could be treated with the CD-M “host” to regenerate the ConA and E. coli-binding surface. This “use-regenerate” cycle could be repeated multiple times without significant loss of bioactivity. Given the generality and versatility of this approach, it may provide the basis for the development of re-usable biosensors and diagnostic devices for the detection and measurement of proteins and bacteria.
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