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1.
Cyclodextrin‐based controlled delivery materials have previously been developed for controlled release of different therapeutic drugs. In this study, a supramolecular hydrogel made from cyclodextrin‐based macromonomers is subjected to molecular imprinting to investigate the impact on release kinetics and drug loading, when compared with non‐imprinted, or alternately imprinted hydrogels. Mild synthesis conditions are used to molecularly imprint three antibiotics—novobiocin, rifampicin, and vancomycin—and to test two different hydrogel chemistries. The release profile and drug loading of the molecularly imprinted hydrogels are characterized using ultraviolet spectroscopy over a period of 35 days and compared to non‐imprinted, and alternately imprinted hydrogels. While only modest differences are observed in the release rate of the antibiotics tested, a substantial difference is observed in the total drug‐loading amount possible for hydrogels releasing drugs which has been templated by those drugs. Hydrogels releasing drugs which are templated by other drugs do not show improved release or loading. Analysis by FTIR does not show substantial incorporation of drug into the polymer. Lastly, bioactivity assays confirmed long‐term stability and release of incorporated antibiotics. 相似文献
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Zehua Li Amanda K. Pearce Jianzhong Du Andrew P. Dove Rachel K. O'Reilly 《Journal of polymer science. Part A, Polymer chemistry》2023,61(1):44-55
Crystallization-driven self-assembly (CDSA) was employed for the preparation of monodisperse cationic cylindrical nanoparticles with controllable sizes, which were subsequently explored for their effect on antibacterial activity and the mechanical properties of nanocomposite hydrogels. Poly(ɛ-caprolactone)-block-poly(methyl methacrylate)-block-poly[2-(tert-butylamino) ethyl methacrylate] (PCL-b-PMMA-b-PTA) triblock copolymers were synthesized using combined ring-opening and RAFT polymerizations, and then self-assembled into polycationic cylindrical micelles with controllable lengths by epitaxial growth. The polycationic cylinders exhibited intrinsic cell-type-dependent antibacterial capabilities against gram-positive and gram-negative bacteria under physiological conditions, without quaternization or loading of any additional antibiotics. Furthermore, when the cylinders were combined into anionic alginate hydrogel networks, the mechanical response of the hydrogel composite was tunable and enhanced up to 51%, suggesting that cationic polymer fibers with controlled lengths are promising mimics of the fibrous structures in natural extracellular matrix to support scaffolds. Overall, this polymer fiber/hydrogel nanocomposite shows potential as an injectable antibacterial biomaterial, with possible application in implant materials as bacteriostatic agents or bactericides against various infections. 相似文献
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Bacterial infections and the associated morbidity and mortality due to bacterial pathogens in wounds and medical implants have been increasing as most of current coatings cannot fulfill all the requirements including excellent intrinsically antibacterial activity, low cytotoxicity, and favorable physical properties. Herein, we present a kind of antibacterial hydrogel based on ε-poly(L-lysine) (EPL) grafted carboxymethyl chitosan (CMC-g-EPL) as the inherently antibacterial matrix and the surplus EPL as highly efficient antimicrobial agent. Such hydrogels possess tunable swelling abilities with water absorption percentages of 800%-2000% and modulus varying from 10 kPa to 100 kPa, and exhibit two-stage excellent antibacterial behavior. First, the free EPL can be released from the hydrogel network for quick and highly efficient bacteria killing with 99.99% of efficacy; second, the grafted EPL endows hydrogel matrix with prolonged intrinsically antibacterial activity, especially when most of free EPL is released from the hydrogel. Overall, we provide a new insight for preparing highly effective antibacterial hydrogels. 相似文献
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Yiming Wang Zhi Xu Matija Lovrak Vincent A. A. le Sage Kai Zhang Xuhong Guo Rienk Eelkema Eduardo Mendes Jan H. van Esch 《Angewandte Chemie (International ed. in English)》2020,59(12):4830-4834
Supramolecular structures with strain‐stiffening properties are ubiquitous in nature but remain rare in the lab. Herein, we report on strain‐stiffening supramolecular hydrogels that are entirely produced through the self‐assembly of synthetic molecular gelators. The involved gelators self‐assemble into semi‐flexible fibers, which thereby crosslink into hydrogels. Interestingly, these hydrogels are capable of stiffening in response to applied stress, resembling biological intermediate filaments system. Furthermore, strain‐stiffening hydrogel networks embedded with liposomes are constructed through orthogonal self‐assembly of gelators and phospholipids, mimicking biological tissues in both architecture and mechanical properties. This work furthers the development of biomimetic soft materials with mechanical responsiveness and presents potentially enticing applications in diverse fields, such as tissue engineering, artificial life, and strain sensors. 相似文献
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A β‐Lactamase‐Imprinted Responsive Hydrogel for the Treatment of Antibiotic‐Resistant Bacteria 下载免费PDF全文
Wen Li Kai Dong Prof. Jinsong Ren Prof. Xiaogang Qu 《Angewandte Chemie (International ed. in English)》2016,55(28):8049-8053
Antibiotics play important roles in infection treatment and prevention. However, the effectiveness of antibiotics is now threatened by the prevalence of drug‐resistant bacteria. Furthermore, antibiotic abuse and residues in the environment cause serious health issues. In this study, a stimuli‐responsive imprinted hydrogel was fabricated by using β‐lactamase produced by bacteria for deactivating antibiotics as the template molecule. The imprinted hydrogel could initially trap β‐lactamase excreted by drug‐resistant bacteria, thus making bacteria sensitive to antibiotics. After the bactericidal treatment, the “imprinted sites” on the hydrogel could be reversibly abolished with a temperature stimulus, which resulted in the reactivation of β‐lactamase to degrade antibiotic residues. We also present an example of the use of this antibacterial design to treat wound infection. 相似文献
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Programmed deformations are widespread in nature, providing elegant paradigms to design self‐morphing materials with promising applications in biomedical devices, flexible electronics, soft robotics, etc. In this emerging field, hydrogels are an ideal material to investigate the deformation principle and the structure‐deformation relationship. One crucial step is to construct heterogeneous structures in a facile yet effective way. Herein, we provide a focus review on different deformation modes and corresponding structural features of hydrogels. Photolithography is a versatile approach to control the outer shape of the hydrogel and spatial distribution of the component in the hydrogel, endowing the patterned hydrogels with programmed internal stress and thus controllable deformations. Specifically, cooperative deformations take place in periodically patterned hydrogels with in‐plane gradients, and multiple morphing structures are formed in one patterned hydrogel using selective preswelling to direct the buckling of each unit. The structural control strategy and deformation principles should be applicable to other materials with broad applications in diverse areas. 相似文献
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Kenshiro Honda Yuka Sazuka Kojiro Iizuka Shusuke Matsui Takayuki Uchihashi Takuma Kureha Mitsuhiro Shibayama Takumi Watanabe Daisuke Suzuki 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(22):7372-7376
Soft colloidal particles such as hydrogel microspheres assemble at air/water or oil/water interfaces, where the soft colloids are highly deformed and their surface polymer chains are highly entangled with each other. Herein, we report the formation of robust one‐dimensional, string‐like colloidal assemblies through self‐organization of hydrogel microspheres with shape anisotropy at the air/water interface of sessile droplets. Shape‐anisotropic hydrogel microspheres were synthesized via two‐step polymerization, whereby a hydrogel shell was formed onto preformed rigid microellipsoids. The shape anisotropy of the hydrogel microspheres was confirmed by transmission electron microscopy and high‐speed atomic force microscopy as well as by light‐scattering measurements. The present findings are crucial for the understanding of natural self‐organization phenomena, where “softness” influences microscopic assembled structures such as those of Nostoc bacteria. 相似文献
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Self‐healing supramolecular hydrogels have emerged as a novel class of biomaterials that combine hydrogels with supramolecular chemistry to develop highly functional biomaterials with advantages including native tissue mimicry, biocompatibility, and injectability. These properties are endowed by the reversibly cross‐linked polymer network of the hydrogel. These hydrogels have great potential for realizing yet to be clinically translated tissue engineering therapies. This review presents methods of self‐healing supramolecular hydrogel formation and their uses in tissue engineering as well as future perspectives. 相似文献
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A series of biodegradable hydrogels based on dextran and poly(L-glutamic acid) were fabricated for effective vancomycin loading and release. The preparation of hydrogels was simply achieved by photo cross-linking of methacrylated dextran and poly(L-glutamic acid)-g-hydroxyethyl methacrylate (PGH) in the presence of photoinitiator 12959. The structures of hydrogels were characterized by FTIR and SEM. The swelling and enzymatic degradation behaviors of hydrogels were examined to be dependent on the poly(L-glutamic acid) content in the hydrogels. The higher content of poly(L-glutamic acid) in the gel, the higher swelling ratio and quicker degradation were observed. More interestingly, the hydrogel with higher PGH ratio showed higher vancomycin (VCM) loading content, which might be due to the electrostatic interaction between carboxylate groups in hydrogel and ammonium group of VCM. In vitro drug release from the VCM-loaded hydrogels in aqueous solution exhibited sustained release of VCM up to 72 h, while the in vitro antibacterial test based on the VCM-loaded hydrogel showed an efficient Methicillin-Resistant S. aureus (MRSA) inhibition extending out to 7 days. These results demonstrated that the biodegradable hydrogels which formed by in situ photo-cross linking would be promising as scaffolds or coatings for local antibacterial drug release in tissue engineering. 相似文献
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Developing a Self‐Healing Supramolecular Nucleoside Hydrogel Based on Guanosine and Isoguanosine 下载免费PDF全文
《化学:亚洲杂志》2018,13(15):1962-1971
Recently, supramolecular hydrogels have attracted increasing interest owing to their tunable stability and inherent biocompatibility. However, only few studies have been reported in the literature on self‐healing supramolecular nucleoside hydrogels, compared to self‐healing polymer hydrogels. In this work, we successfully developed a self‐healing supramolecular nucleoside hydrogel obtained by simply mixing equimolar amounts of guanosine (G) and isoguanosine (isoG) in the presence of K+. The gelation properties have been studied systematically by comparing different alkali metal ions as well as mixtures with different ratios of G and isoG. To this end, rheological and phase diagram experiments demonstrated that the co‐gel not only possessed good self‐healing properties and short recovery time (only 20 seconds) but also could be formed at very low concentrations of K+. Furthermore, nuclear magnetic resonance (NMR), powder X‐ray diffraction (PXRD), and circular dichroism (CD) spectroscopy suggested that possible G2isoG2‐quartet structures occurred in this self‐healing supramolecular nucleoside hydrogel. This co‐gel, to some extent, addressed the problem of isoguanosine gels for the applications in vivo, which showed the potential to be a new type of drug delivery system for biomedical applications in the future. 相似文献
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Self‐healing hydrogel such as polyacrylic acid (PAA) hydrogel has attracted increasing attention based on its promising potential applications. However, it usually suffers from low strength especially as mechanical device. Herein, a commercial microcrystalline cellulose (MCC) was modified with acrylamide to graft polyacrylamide (PAM) chains on the particle surface. The acrylamide‐modified MCC (AM‐MCC) was then dispersed in monomer solution of acrylic acid to prepare composite hydrogel. The mechanical properties of the obtained composite hydrogels and the self‐healed hydrogels were carefully measured by compressive and tensile tests, and by dynamic mechanical analysis. Our results demonstrate that introduction of a small amount of AM‐MCC such as 3 wt% can not only reinforce the original hydrogel and the healed hydrogel markedly, but also improve self‐healing efficiency obviously. The analyses indicate that in addition to the reversible multi‐interactions such as hydrogen bonding and ionic interactions, the entanglements between the PAA chains of the hydrogel matrix and the PAM chains grafted on the MCC particles have also played an important role on the improvement in mechanical performances and the healing ability of the hydrogel. Moreover, the responsiveness to exterior ion has been tested to indicate potential application of the composite hydrogel as self‐healable sensor. 相似文献
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《Macromolecular bioscience》2017,17(11)
A generally applicable strategy to obtain mechanically robust hydrogels for the incorporation and containment of functional reporter bacteria for the microarray and microparticle‐based detection and signaling of N‐acyl homoserine lactone autoinducers (3OC12HSL) at relevant concentrations is reported. For reinforcing hydrogels of 1,4‐bi(phenylalanine‐diglycol)‐benzene (PDB), a hybrid hydrogel is formed by the combination of PDB self‐assembly with Ca2+ mediated alginate crosslinking. The different assembly mechanisms are shown not to interfere with each other and despite the more than four‐fold increased moduli of the hydrogels, diffusion of autoinducers into the gels remains efficient and Escherichia coli pLuxR‐green fluorescent protein (GFP) reporter bacteria are proliferating. Templating affords reporter bacteria‐loaded hydrogels with controllable shape and size. Upon exposure to 3OC12HSL, the embedded bacteria exhibit an up to 12 ± 3 times increase in fluorescence intensity due to autoinducer‐triggered GFP expression. This approach can serve as a potentially generally applicable strategy to sensitively detect bacteria via their secreted autoinducers. 相似文献
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Xiaoyu Wang Rijian Song Melissa Johnson Sigen A Pingping Shen Nan Zhang Irene Lara-Sáez Qian Xu Wenxin Wang 《Macromolecular bioscience》2023,23(9):2300094
Wound infections slow down the healing process and lead to complications such as septicemia, osteomyelitis, and even death. Although traditional methods relying on antibiotics are effective in controlling infection, they have led to the emergence of antibiotic-resistant bacteria. Hydrogels with antimicrobial function become a viable option for reducing bacterial colonization and infection while also accelerating healing processes. Chitosan is extensively developed as antibacterial wound dressings due to its unique biochemical properties and inherent antibacterial activity. In this review, the recent research progress of chitosan-based hydrogels for infected wound treatment, including the fabrication methods, antibacterial mechanisms, antibacterial performance, wound healing efficacy, etc., is summarized. A concise assessment of current limitations and future trends is presented. 相似文献
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《Macromolecular rapid communications》2017,38(17)
Strong and tough synthetic hydrogels have received ever‐increasing interests due to their potential applications as load‐bearing structural materials. However, strong, tough, and recyclable hydrogels in different forms that can be generated by different methods according to various practical applications still remain an intrinsic bottleneck. A simple one‐pot synthesis of multiurea linkage segmented linear copolymers with easy recyclability, hybridization, and processability, including compression molding, solution casting, and spinning methods, to yield ultrastrong and tough hydrogel films or stretchable hydrogel fibers with diameters ranged from macro‐, micro‐, to nanoscale, is reported here. 相似文献
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Subhasish Roy Abhishek Baral Prof. Arindam Banerjee 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(44):14950-14957
An amino‐acid‐based (11‐(4‐(pyrene‐1‐yl)butanamido)undecanoic acid) self‐repairing hydrogel is reported. The native hydrogel, as well as hybrid hydrogels, have been thoroughly characterized by using various microscopic techniques, including transmission electron microscopy (TEM), atomic force microscopy (AFM), Raman spectroscopy, fluorescence spectroscopy, FTIR spectroscopy, X‐ray diffraction, and by using rheological experiments. The native hydrogel exhibited interesting fluorescence properties, as well as a self‐healing property. Interestingly, the self‐healing, thixotropy, and stiffness of the native hydrogel can be successfully modulated by incorporating carbon‐based nanomaterials, including graphene, pristine single‐walled carbon nanotubes (Pr‐SWCNTs), and both graphene and Pr‐SWCNTs, within the native gel system. The self‐recovery time of the gel was shortened by the inclusion of reduced graphene oxide (RGO), Pr‐SWCNTs, or both RGO and Pr‐SWCNTs. Moreover, hybrid gels that contained RGO and/or Pr‐SWCNTs exhibited interesting semiconducting behavior. 相似文献
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Antibacterial poly(ethylene glycol) hydrogels from combined epoxy‐amine and thiol‐ene click reaction 下载免费PDF全文
Chao Zhou Vinh X. Truong Yue Qu Trevor Lithgow Guodong Fu John S. Forsythe 《Journal of polymer science. Part A, Polymer chemistry》2016,54(5):656-667
Antibacterial hydrogels containing quaternary ammonium (QA) groups were prepared via a facile thiol‐ene “click” reaction using multifunctional poly(ethylene glycol) (PEG). The multifunctional PEG polymers were prepared by an epoxy‐amine ring opening reaction. The chemical and physical properties of the hydrogels could be tuned with different crosslinking structures and crosslinking densities. The antibacterial hydrogel structures prepared from PEG Pendant QA were less well‐defined than those from PEG Chain‐End QA. Furthermore, functionalization of the PEG‐type hydrogels with QA groups produced strong antibacterial abilities against Staphylococcus aureus, and therefore has the potential to be used as an anti‐infective material for biomedical devices. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 656–667 相似文献
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Vicent J. Nebot José Armengol Dr. Johan Smets Susana Fernández Prieto Dr. Beatriu Escuder Dr. Juan F. Miravet 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(13):4063-4072
Insight is provided into the aggregation thermodynamics associated to hydrogel formation by molecular gelators derived from L ‐valine and L ‐isoleucine. Solubility data from NMR measurements are used to extract thermodynamic parameters for the aggregation in water. It is concluded that at room temperature and up to 55 °C, these systems form self‐assembled fibrillar networks in water with quite low or zero enthalpic component, whereas the entropy of the aggregation is favorable. These results are explained by considering that the hydrophobic effect is dominant in the self‐assembly. However, studies by NMR and IR spectroscopy reveal that intermolecular hydrogen bonding is also a key issue in the aggregation process of these molecules in water. The low enthalpy values measured for the self‐assembly process are ascribed to the result of a compensation of the favorable intermolecular hydrogen‐bond formation and the unfavorable enthalpy component of the hydrophobic effect. Additionally, it is shown that by using the hydrophobic character as a design parameter, enthalpy‐controlled hydrogel formation, as opposed to entropy‐controlled hydrogel formation, can be achieved in water if the gelator is polar enough. It is noteworthy that these two types of hydrogels, enthalpy‐versus entropy‐driven hydrogels, present quite different response to temperature changes in properties such as the minimum gelator concentration (mgc) or the rheological moduli. Finally, the presence of a polymorphic transition in a hydrogel upon heating above 70 °C is reported and ascribed to the weakening of the hydrophobic effect upon heating. The new soft polymorphic materials present dramatically different solubility and rheological properties. Altogether these results are aimed to contribute to the rational design of molecular hydrogelators, which could be used for the tailored preparation of this type of soft materials. The reported results could also provide ground for the rationale of different self‐assembly processes in aqueous media. 相似文献