RESUMO
Oral defects lead to a series of function disorders, severely threatening the patients' health. Although injectable hydrogels are widely studied in tissue regeneration, their mechanical performance is usually stationary after implant, without further self-adaption toward the microenvironment. Herein, an injectable hydrogel with programmed mechanical kinetics of instant gelation and gradual self-strengthening along with outstanding biodegradation ability is developed. The fast gelation is realized through rapid Schiff base reaction between biodegradable chitosan and aldehyde-modified sodium hyaluronate, while self-strengthening is achieved via slow reaction between redundant amino groups on chitosan and epoxy-modified hydroxyapatite. The resultant hydrogel also possesses multiple functions including (1) bio-adhesion, (2) self-healing, (3) bactericidal, (4) hemostasis, and (5) X-ray in situ imaging, which can be effectively used for oral jaw repair. We believe that the strategy illustrated here will provide new insights into dynamic mechanical regulation of injectable hydrogels and promote their application in tissue regeneration.
Assuntos
Quitosana , Hidrogéis , Humanos , Cinética , Polissacarídeos , DurapatitaRESUMO
Polyzwitterionic brushes with strong antipolyelectrolyte effects have shown great potential as versatile platforms for the development of switchable friction/lubrication and bacterial absorption/desorption surfaces. However, the surface property switches of these brushes are usually triggered by high salt concentrations (>0.53 M), thereby greatly limiting their applications in biological fields where the salt concentration for mammals is ?0.15 M. To solve this problem, an electric field was used to assist the salt-responsive process of the polyzwitterionic brushes to achieve bacterial release at low concentrations of the salt solution. Briefly, poly(3-(dimethyl (4-vinylbenzyl) ammonium) propyl sulfonate) (polyDVBAPS) brushes grafted on ITO surfaces were prepared by surface initiated atom transfer radical polymerization. The bacterial release of this surface was conducted under an electric field, where anions were migrated and enriched around the brush-grafted ITO surface as anode. The local high concentration ion led to the conformation change of the brush and release of the attached bacteria. The effect of salt type, salt concentration, electric field strength, and conducting time on the bacterial release properties were investigated. The results indicated that under an electrical field of 3 V/mm, polyDVBAPS showed release capacities of ?93% for E. coli and ?81% for S. aureus in 0.12 M NaCl electrolyte solution. Furthermore, by the introduction of a bactericidal agent, i.e., Triclosan (TCS), an antibacterial surface with dual functions of killing and release was fabricated. This surface could kill ?90% and release 95% of attached E. coli in a 0.12 M NaCl solution by the application of a 3 V/mm electric field. This work demonstrated the feasibility of triggering a salt-responsive behavior of polyzwitterionic at low salt concentration by assistance of electric field, which would greatly extend the applications of polyzwitterionic, in particular in biological applications.
Assuntos
Antibacterianos/farmacologia , Polímeros/farmacologia , Cloreto de Sódio/farmacologia , Escherichia coli/efeitos dos fármacos , Polimerização , Polímeros/química , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Triclosan/químicaRESUMO
Antibacterial surfaces with both bacteria killing and release functions show great promise in biological and biomedical applications, in particular for reusable medical devices. However, these surfaces either require a sophisticated technique to create delicate structures or need rigorous stimuli to trigger the functions, greatly limiting their practical application. In this study, we made a step forward by developing a simple system based on a salt-responsive polyzwitterionic brush. Specifically, the salt-responsive brush of poly(3-(dimethyl (4-vinylbenzyl) ammonium) propyl sulfonate) (polyDVBAPS) was endowed with bactericidal function by grafting an effective bactericide, i.e., triclosan (TCS). This simple functionalization successfully integrated the bacteria attach/release function of polyDVBAPS and bactericidal function of TCS. As a result, the surface could kill more than 95% attached bacteria and, subsequently, could rapidly detach â¼97% bacteria after gently shaking in 1.0 M NaCl for 10 min. More importantly, such high killing efficiency and release rate could be well retained (unchanged effectiveness of both killing and release after four severe killing/release cycles), indicating the highly efficient regeneration and long-term reusability of this system. This study not only contributes zwitterionic polymers by conferring new functions but also provides a new, highly efficient and reliable surface for "killing-release" antibacterial strategy.
Assuntos
Bactérias , Antibacterianos , Polímeros , Cloreto de Sódio , TriclosanRESUMO
Development of smart, multifunction materials is challenging but important for many fundamental and industrial applications. Here, we synthesized and characterized zwitterionic poly(3-(1-(4-vinylbenzyl)-1H-imidazol-3-ium-3-yl)propane-1-sulfonate) (polyVBIPS) brushes as ion-responsive smart surfaces via the surface-initiated atom transfer radical polymerization. PolyVBIPS brushes were carefully characterized for their surface morphologies, compositions, wettability, and film thicknesses by atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle, and ellipsometer, respectively. Salt-responsive, switching properties of polyVBIPS brushes on surface hydration, friction, and antifouling properties were further examined and compared both in water and in salt solutions with different salt concentrations and counterion types. Collective data showed that polyVBIPS brushes exhibited reversible surface wettability switching between in water and saturated NaCl solution. PolyVBIPS brushes in water induced the larger protein absorption, higher surface friction, and lower surface hydration than those in salt solutions, exhibiting "anti-polyelectrolyte effect" salt responsive behaviors. At appropriate ionic conditions, polyVBIPs brushes were able to switch to superlow fouling surfaces (<0.3 ng/cm(2) protein adsorption) and superlow friction surfaces (u â¼ 10(-3)). The relationship between brush structure and its salt-responsive performance was also discussed. This work provides new zwitterionic surface-responsive materials with controllable antifouling and friction capabilities for multifunctional applications.
Assuntos
Fricção , Polímeros/química , Polímeros/síntese química , Microscopia de Força Atômica , Propriedades de SuperfícieRESUMO
Rational design of effective antifouling polymers is challenging but important for many fundamental and applied applications. Herein we synthesize and characterize an N-acryloylaminoethoxyethanol (AAEE) monomer, which integrates three hydrophilic groups of hydroxyl, amide, and ethylene glycol in the same material. AAEE monomers were further grafted and polymerized on gold substrates to form polyAAEE brushes with well-controlled thickness via surface-initiated atomic transfer radical polymerization (SI-ATRP), with particular attention to a better understanding of the molecular structure-antifouling property relationship of hydroxyl-acrylic-based polymers. The surface hydrophilicity and antifouling properties of polyAAEE brushes as a function of film thickness are studied by combined experimental and computational methods including surface plasmon resonance (SPR) sensors, atomic force microscopy (AFM), cell adhesion assay, and molecular dynamics (MD) simulations. With the optimal polymer film thicknesses (â¼10-40 nm), polyAAEE-grafted surfaces can effectively resist protein adsorption from single-protein solutions and undiluted human blood plasma and serum to a nonfouling level (i.e., <0.3 ng/cm(2)). The polyAAEE brushes also highly resist mammalian cell attachment up to 3 days. MD simulations confirm that the integration of three hydrophilic groups induce a stronger and closer hydration layer around polyAAEE, revealing a positive relationship between surface hydration and antifouling properties. The molecular structure-antifouling properties relationship of a series of hydroxyl-acrylic-based polymers is also discussed. This work hopefully provides a promising structural motif for the design of new effective antifouling materials beyond traditional ethylene glycol-based antifouling materials.
Assuntos
Resinas Acrílicas/química , Adesão Celular , Proteínas/química , Adsorção , Microscopia de Força Atômica , Simulação de Dinâmica Molecular , Espectroscopia de Prótons por Ressonância MagnéticaRESUMO
Numerous biocompatible antifouling polymers have been developed for a wide variety of fundamental and practical applications in drug delivery, biosensors, marine coatings, and many other areas. Several antifouling mechanisms have been proposed, but the exact relationship among molecular structure, surface hydration property, and antifouling performance of antifouling polymers still remains elusive. Here this work strives to provide a better understanding of the structure-property relationship of poly(N-hydroxyalkyl acrylamide)-based materials. We have designed, synthesized, and characterized a series of polyHAAA brushes of various carbon spacer lengths (CSLs), that is, poly(N-hydroxymethyl acrylamide) (polyHMAA), poly(N-(2-hydroxyethyl)acrylamide) (polyHEAA), poly(N-(3-hydroxypropyl)acrylamide) (polyHPAA), and poly(N-(5-hydroxypentyl)acrylamide) (polyHPenAA), to study the structural dependence of CSLs on their antifouling performance. HMAA, HEAA, HPAA, and HPenAA monomers contained one, two, three, and five methylene groups between hydroxyl and amide groups, while the other groups in polymer backbones were the same as each other. The relation of such small structural differences of polymer brushes to their surface hydration and antifouling performance was studied by combined experimental and computational methods including surface plasmon resonance sensors, sum frequency generation (SFG) vibrational spectroscopy, cell adhesion assay, and molecular simulations. Antifouling results showed that all polyHAAA-based brushes were highly surface resistant to protein adsorption from single protein solutions, undiluted blood serum and plasma, as well as cell adhesion up to 7 days. In particular, polyHMAA and polyHEAA with the shorter CSLs exhibited higher surface hydration and better antifouling ability than polyHPMA and polyHPenAA. SFG and molecular simulations further revealed that the variation of CSLs changed the ratio of hydrophobicity/hydrophilicity of polymers, resulting in different hydration characteristics. Among them, polyHMAA and polyHEAA with the shorter CSLs showed the highest potency for surface hydration and antifouling abilities, while polyHPenAA showed the lowest potency. The combination of both hydroxyl and amide groups in the same polymer chain provides a promising structural motif for the design of new effective antifouling materials.
Assuntos
Resinas Acrílicas , Aorta/metabolismo , Células Endoteliais/metabolismo , Teste de Materiais , Resinas Acrílicas/síntese química , Resinas Acrílicas/química , Resinas Acrílicas/farmacologia , Animais , Aorta/citologia , Bovinos , Células Cultivadas , Células Endoteliais/citologia , Relação Estrutura-AtividadeRESUMO
Chemotherapy is the main treatment for bladder cancer, but drug resistance and side effects limit its application and therapeutic effect. Herein, we constructed doxorubicin (DOX)/COOH-mesoporous silica nanoparticle/polyethylenimine (PEI)/nucleic acid chimeras (DOX/MSN/Chimeras) to reduce the toxicity of chemotherapy drugs and the resistance of bladder cancer cells. Transmission electron microscopy showed that PEI was coated on the DOX/MSN/BSA nanoparticles with a diameter of about 150â¯nm. DOX/MSN/PEI could control DOX release for over 48â¯h, and the sudden release rate was significantly lower than DOX/MSN. Immunohistochemical results showed that DOX/MSN/Chimera specifically bound to bladder cancer cells, and markedly inhibited PI3K expression and proliferation of DOX-resistant bladder cancer cells. DOX/MSN/Chimera promoted the apoptosis of drug-resistant bladder cancer cells, which was superior to DOX/MSN/Aptamer or DOX/MSN. We further carried out animal experiments and found that DOX/MSN/Chimera could reduce the volume of transplanted tumors in vivo. Compared with DOX/MSN/Aptamer group, the proliferation rate was significantly decreased and the proportion of apoptotic cells was highly increased. Through the histological observation of kidneys and lungs, we believed that DOX/MSN/Chimera can effectively reduce the damage of chemotherapy drugs to normal tissues. In conclusion, we constructed a COOH-MSN/nucleic acid chimera conjugate for the targeted delivery of siRNA and anti-cancer drugs. Our study provides a new method for personalized and targeted treatment of drug-resistant bladder cancer.
Assuntos
Doxorrubicina , Resistencia a Medicamentos Antineoplásicos , Camundongos Nus , Nanopartículas , RNA Interferente Pequeno , Dióxido de Silício , Neoplasias da Bexiga Urinária , Neoplasias da Bexiga Urinária/tratamento farmacológico , Neoplasias da Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/genética , Doxorrubicina/farmacologia , Doxorrubicina/administração & dosagem , Dióxido de Silício/química , Animais , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Humanos , Nanopartículas/química , Linhagem Celular Tumoral , RNA Interferente Pequeno/administração & dosagem , RNA Interferente Pequeno/farmacologia , Porosidade , Camundongos , Apoptose/efeitos dos fármacos , Camundongos Endogâmicos BALB C , Ácidos Nucleicos/administração & dosagem , Polietilenoimina/química , Ensaios Antitumorais Modelo de Xenoenxerto , Portadores de Fármacos/química , Proliferação de Células/efeitos dos fármacos , Sistemas de Liberação de Medicamentos/métodos , Antibióticos Antineoplásicos/farmacologia , Antibióticos Antineoplásicos/administração & dosagemRESUMO
Pesticides are widely used to increase agricultural productivity, however, weak adhesion and deposition lead to low efficient utilization. Herein, we prepare a nanopesticide formulation (tebuconazole nanopesticides) which is leaf-adhesive, and water-dispersed via a rapid nanoparticle precipitation method, flash nanoprecipitation, using temperature-responsive copolymers poly-(2-(dimethylamino)ethylmethylacrylate)-b-poly(ε-caprolactone) as the carrier. Compared with commercial suspensions, the encapsulation by the polymer improves the deposition of TEB, and the contact angle on foliage is lowered by 40.0°. Due to the small size and strong van der Waals interactions, the anti-washing efficiency of TEB NPs is increased by 37% in contrast to commercial ones. Finally, the acute toxicity of TEB NPs to zebrafish shows a more than 25-fold reduction as compared to commercial formulation indicating good biocompatibility of the nanopesticides. This work is expected to enhance pesticide droplet deposition and adhesion, maximize the use of pesticides, tackling one of the application challenges of pesticides.
Assuntos
Praguicidas , Água , Animais , Temperatura , Peixe-Zebra , Polímeros , Folhas de PlantaRESUMO
Microplastics have been widely detected in the effluent discharged from wastewater treatment plants. However, few studies have focused on the occurrence of microplastics in the sediments of waterbodies receiving reclaimed water. The present study investigated the microplastics distribution in the sediments of such a lake in Tianjin, China receiving reclaimed water and determined the factors affecting the settlement of microplastics in the sediment column. Nine sediment cores were collected and the abundance, shape, size, and color of the microplastics were determined. The polymers of microplastics were identified and the mass concentrations of polyethylene terephthalate (PET) and polycarbonate (PC) were analyzed. Large amount of microplastics were found to accumulate in the sediments of the lake receiving reclaimed water. Eighteen polymers were found in the sediments and PA, PET, PP, PSF, and PU are much more than others. In surface sediments, PET and PC ranged from 2.43 to 10.62 mg/kg and 0.03 to 0.77 mg/kg, respectively. Fragment and fiber are the most common shapes, accounting for 67.5% and 24.8% of all the microplastics. The distribution of microplastics was influenced by polymer type, size, shape, and grain size of the sediments. Microplastic morphological diversities decreased with increasing depth of the sediments. Our findings provide evidence that the sediments of receiving waterbodies are important sinks of the microplastics in reclaimed water.
Assuntos
Microplásticos , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Lagos , Plásticos , Água , Poluentes Químicos da Água/análiseRESUMO
The formation and stabilization mechanism as well as digestion characteristics of food-grade emulsions prepared by the SPNPs-HPMC mixed systems (a combination of soybean protein isolate-pectin composite nanoparticles (SPNPs) and hydroxypropyl methylcellulose (HPMC)) were investigated. Then, it was found that the SPNPs-HPMC mixed systems could not only enhance the stability of the emulsion, but also make it have a satisfactory lipidolys is efficiency. During the formation and stabilization of the emulsion, HPMC was adsorbed in the early stage of emulsion formation, while SPNPs needed a longer adsorption time. When the HPMC concentration was 0.25-0.5 wt%, HPMC and SPNPs co-adsorbed on the interface. When the HPMC concentration was 1-2 wt%, HPMC and SPNPs competed to adsorb on the interface, of which the adsorption HPMC was dominant. In vitro simulation of digestion, SPNPs were decomposed into substances with lower interfacial activity, and the structure and activity of HPMC were well maintained, which led them to reconstruct a new interface layer. Thus, the size distribution and surface area of the emulsion droplets were retained in a good state for the lipidolysis process. Therefore, the SPNPs-HPMC mixed systems could both enhance the stability of the emulsion and grant it a satisfactory lipidolysis efficiency.
Assuntos
Nanopartículas , Proteínas de Soja , Emulsões/química , Derivados da Hipromelose/química , Metilcelulose/química , Nanopartículas/química , Pectinas/química , Proteínas de Soja/químicaRESUMO
Bacterial infections from biomedical devices pose a great threat to the health of humans and thus place a heavy burden on society. Therefore, developing efficient antibacterial surfaces has attracted much attention. However, it is a challenge to identify or develop a combination that efficiently integrates multiple functions via topological tailoring and on-demand function-switch via non-contact and noninvasive stimuli. To resolve this issue, a highly hydrophilic comb polymer brush was constructed here based on supramolecular host-guest recognition. Azobenzene (azo)-modified antifouling and antibacterial polymers were incorporated into cyclodextrin (CD)-modified antifouling polymer brushes grafted on the surface. The surface thus obtained possessed excellent antifouling performance with a low bacterial density of â¼6.25 × 105 cells per cm2 after 48 h and exhibited a high efficiency of â¼88.2% for killing bacteria. Besides, irradiation with UV light resulted in the desorption of the azo-polymers and a release of â¼85.1% attached bacteria. Irradiating visible light led to the re-adsorption of azo-polymers, which regenerated the fresh surface; the process could be repeated for at least three cycles, and the surface still maintained low bacterial attachments with a cell density of â¼7.10 × 105 cells per cm2, high sterilization efficiency of â¼93.8%, and a bacteria release rate of â¼83.1% in the 3rd cycle. The photo-switchable antibacterial surface presented in this research will provide new insights into the development of smart biomedical surfaces.
Assuntos
Infecções Bacterianas , Polímeros , Antibacterianos/farmacologia , Bactérias , Humanos , Interações Hidrofóbicas e HidrofílicasRESUMO
Development of smart switchable surfaces to solve the inevitable bacteria attachment and colonization has attracted much attention; however, it proves very challenging to achieve on-demand regeneration for noncontaminated surfaces. We herein report a smart, host-guest interaction-mediated photo/temperature dual-controlled antibacterial surface, topologically combining stimuli-responsive polymers with nanobactericide. From the point of view of long-chain polymer design, the peculiar hydration layer generated by hydrophilic poly(2-hydroxyethyl methacrylate) (polyHEMA) segments severs the route of initial bacterial attachment and subsequent proliferation, while the synergistic effect on chain conformation transformation poly(N-isopropylacrylamide) (polyNIPAM) and guest complex dissociation azobenzene/cyclodextrin (Azo/CD) complex greatly promotes the on-demand bacterial release in response to the switch of temperature and UV light. Therefore, the resulting surface exhibits triple successive antimicrobial functions simultaneously: (i) resists â¼84.9% of initial bacterial attachment, (ii) kills â¼93.2% of inevitable bacteria attack, and (iii) releases over 94.9% of killed bacteria even after three cycles. The detailed results not only present a potential and promising strategy to develop renewable antibacterial surfaces with successive antimicrobial functions but also contribute a new antimicrobial platform to biomedical or surgical applications.
Assuntos
Antibacterianos/química , Compostos Azo/química , Materiais Biocompatíveis/química , Ciclodextrinas/química , Polímeros/química , Antibacterianos/farmacologia , Compostos Azo/farmacologia , Bactérias/efeitos dos fármacos , Infecções Bacterianas/prevenção & controle , Materiais Biocompatíveis/farmacologia , Ciclodextrinas/farmacologia , Humanos , Interações Hidrofóbicas e Hidrofílicas , Nanoestruturas/química , Poli-Hidroxietil Metacrilato/química , Poli-Hidroxietil Metacrilato/farmacologia , Polímeros/farmacologia , Temperatura , Raios UltravioletaRESUMO
Numerous efforts to fabricate antimicrobial surfaces by simple yet universal protocols with high efficiency have attracted considerable interest but proved to be particularly challenging. Herein, we designed and fabricated a series of antimicrobial polymeric coatings with different functions from single to multiple mechanisms by selectively utilizing diethylene glycol diglycidyl ether (PEGDGE), polylysine, and poly[glycidylmethacrylate-co-3-(dimethyl(4-vinylbenzyl)ammonium)propyl sulfonate] (poly(GMA-co-DVBAPS)) via straightforward mussel-inspired codeposition techniques. Bactericidal polylysine endowed the modified surfaces with a high ability (â¼90%) to kill attached bacteria, while PEGDGE components with unique surface hydration prevented bacterial adhesion, avoiding the initial biofilm formation. Moreover, excellent salt-responsive poly(GMA-co-DVBAPS) enabled reactant polymeric coatings to change chain conformations from shrinkable to stretchable state and subsequently release >90% attached bacteria when treated with NaCl solution, even after repeated cycles. Therefore, the obtained polymeric coatings, polydopamine/poly(GMA-co-DVBAPS) (PDA/PDV), polydopamine/polylysine/poly(GMA-co-DVBAPS) (PDA/l-PDV), and polydopamine/polylysine/poly(GMA-co-DVBAPS)/diethylene glycol diglycidyl ether (PDA/l-PDV-PEGDGE), controllably realized functions from single and dual to multiple antimicrobial mechanisms, as evidenced by long-term antifouling activity to bacteria, high bactericidal efficiency, and salt-responsive bacterial regeneration performance with several bacterial killing-release cycles. This study not only contributes to mussel-inspired chemistry for polymeric coatings with controllable functions but also provides a series of reliable and highly efficient antimicrobial surfaces for potential biomedical applications.
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Materiais Revestidos Biocompatíveis/química , Materiais Revestidos Biocompatíveis/farmacologia , Polímeros/química , Polímeros/farmacologia , Animais , Aderência Bacteriana/efeitos dos fármacos , Infecções Bacterianas/microbiologia , Infecções Bacterianas/prevenção & controle , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Bivalves/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Etilenoglicóis/química , Etilenoglicóis/farmacologia , Humanos , Indóis/química , Indóis/farmacologia , Polilisina/química , Polilisina/farmacologia , Ácidos Polimetacrílicos/química , Ácidos Polimetacrílicos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Propriedades de SuperfícieRESUMO
Development of biological dressings has received widespread attentions due to their good breathability, biocompatibility, wettability, and the ability to absorb wound exudate without sticking to the wound. However, current proposed antibacterial hydrogels are limited antibacterial ability, short service life and insufficient biocompatibility, which are still challenging to address intricate practical applications. Here we develop a cationic peptide-based, salt-responsive hydrogel dressing with triple functions of antifouling, bactericidal, and bacterial release by combining ε-poly-l-lysine, poly(ethylene glycol) diglycidyl ether, and poly(DVBAPS-co-GMA) via a one-pot method. These designed hydrogels enabled to further quaternize to enhance antibacterial property due to the presence of amine residues. The resultant hydrogels present good antibacterial activity (>90%), biocompatibility, cell proliferation efficacy (~400%) and adhesiveness. Through in vivo and in vitro antibacterial capability tests, it is also found that hydrogels have good antifouling and sterilization capabilities, and the sterilization rate could reach up to ~96%. In addition, ~94% of the attached bacterial can be released after saline/water switching for several cycles. Taken together, the designed multiple antibacterial dressing prolongs the lifespan relying on reversible salt-responsive release and meet special requirements for wound healing. This work not only provides a platform to highlight its promising potentials in wound management but also gives a custom strategy to biomedical applications.
Assuntos
Antibacterianos/farmacologia , Curativos Hidrocoloides , Peptídeos/farmacologia , Sais/química , Cicatrização/efeitos dos fármacos , Animais , Cátions , Morte Celular/efeitos dos fármacos , Linhagem Celular , Compostos de Epóxi/química , Resinas Epóxi/química , Escherichia coli/efeitos dos fármacos , Feminino , Metacrilatos/química , Camundongos , Testes de Sensibilidade Microbiana , Espectroscopia de Prótons por Ressonância Magnética , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
The development of smart materials and surfaces with multiple antibacterial actions is of great importance for both fundamental research and practical applications, but this has proved to be extremely challenging. In this work, we proposed to integrate salt-responsive polyDVBAPS (poly(3-(dimethyl(4-vinylbenzyl) ammonio)propyl sulfonate)), antifouling polyHEAA (poly(N-hydroxyethyl acrylamide)), and bactericidal TCS (triclosan) into single surfaces by polymerizing and grafting polyDVBAPS and polyHEAA onto the substrate in a different way to form two types of polyDVBAPS/poly(HEAA-g-TCS) and poly(DVBAPS-b-HEAA-g-TCS) brushes with different hierarchical structures, as confirmed by X-ray photoelectron spectroscopy (XPS), atom force microscopy (AFM), and ellipsometry. Both types of polymer brushes demonstrated their tri-functional antibacterial activity to resist bacterial attachment by polyHEAA, to release â¼90% of dead bacteria from the surface by polyDVBAPS, and to kill â¼90% of bacteria on the surface by TCS. Comparative studies also showed that removal of any component from polyDVBAPS/poly(HEAA-g-TCS) and poly(DVBAPS-b-HEAA-g-TCS) compromised the overall antibacterial performance, further supporting a synergistic effect of the three compatible components. More importantly, the presence of salt-responsive polyDVBAPS allowed both brushes to regenerate with almost unaffected antibacterial capacity for reuse in multiple kill-and-release cycles. The tri-functional antibacterial surfaces present a promising design strategy for further developing next-generation antibacterial materials and coatings for antibacterial applications.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Polímeros/química , Animais , Antibacterianos/química , Aderência Bacteriana/efeitos dos fármacos , Incrustação Biológica/prevenção & controle , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Camundongos , Polímeros/farmacologia , Silício/química , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Propriedades de SuperfícieRESUMO
UNLABELLED: Development of smart regenerative surface is a highly challenging but important task for many scientific and industrial applications. Specifically, very limited research efforts were made for surface regeneration between bio-adhesion and antifouling properties, because bioadhesion and antifouling are the two highly desirable but completely opposite properties of materials. Herein, we developed salt-responsive polymer brushes of poly(3-(1-(4-vinylbenzyl)-1H-imidazol-3-ium-3-yl) propane-1-sulfonate) (polyVBIPS), which can be switched reversibly and repeatedly between protein capture/release and surface wettability in a controllable manner. PolyVBIPS brush has demonstrated its switching ability to resist both protein adsorption from 100% blood plasma/serum and bacterial attachment in multiple cycles. PolyVBIPS brush also exhibits reversible surface wettability from â¼40° to 25° between in PBS and in 1M NaCl solutions in multiple cycles. Overall, the salt-responsive behaviors of polyVBIPS brushes can be interpreted by the "anti-polyelectrolyte effect", i.e. polyVBIPS brushes adopt a collapsed chain conformation at low ionic strengths to achieve surface adhesive, but an extended chain conformation at high ionic strength to realize antifouling properties. We expect that polyVBIPS will provide a simple, robust, and promising system for the fabrication of smart surfaces with biocompatible, reliable, and regenerative properties. STATEMENT OF SIGNIFICANCE: Unlike many materials with "one-time switching" capability for surface regeneration, we developed a new regenerative surface of zwitterionic polymer brush, which exhibits a reversible salt-induced switching property between a biomolecule-adhesive state and a biomolecule repellent state in complex media for multiple cycles. PolyVBIPS is easily synthesized and can be straightforward coated on the surface, which provides a simple, robust, and promising system for the fabrication of smart surfaces with biocompatible, reliable, regenerative properties.
Assuntos
Bactérias/metabolismo , Aderência Bacteriana , Proteínas Sanguíneas/química , Materiais Revestidos Biocompatíveis/química , Polímeros/química , Humanos , MolhabilidadeRESUMO
In this study, we report a simple and cost-effective method for self-sterilized complex coatings obtained by Ag@TiO2 particle incorporation into styrene-acrylic latex. The Ag@TiO2 particles were prepared via a coupling agent modification process. The composite latices characterized by transmission electron microscopy (TEM) study were highly homogeneous at the nanometric scale, and the Ag@TiO2 particles were well dispersed and exhibited an intimate contact between both the organic and inorganic components. The Ag@TiO2 nanoparticles significantly enhanced the absorption in the visible region and engendered a good heat-insulating effect of the complex coatings. Moreover, the Ag@TiO2 nanoparticle incorporation into this polymer matrix renders self-sterilized nanocomposite materials upon light excitation, which are tested against Escherichia coli and Staphylococcus aureus. The complex coatings display an impressive performance in the killing of all micro-organisms with a maximum for a Ag@TiO2 loading concentration of 2-5 wt.%. The weathering endurance of the complex coating was also measured.