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1.
Biomacromolecules ; 25(6): 3335-3344, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38717974

RESUMO

Hemostatic powder is widely employed for emergency bleeding control due to its ability to conform to irregularly shaped wounds, ease of use, and stable storage. However, current powders exhibit limited tissue adhesion and insufficient support for thrombus formation, making them easily washed away by blood. In this study, a hybrid powder (QAL) was produced by mixing quaternized chitosan (QCS) powder, catechol-modified alginate (Cat-SA) powder, and laponite (Lap) powder. Upon addition of QAL, the blood quickly transformed to a robust and adhesive blood gel. The adhesion strength of the blood gel was up to 31.33 ± 1.56 kPa. When compared with Celox, QAL showed superior performance in promoting hemostasis. Additionally, QAL exhibited effectiveness in eliminating bacteria while also demonstrating outstanding biocompatibility with cells and blood. These favorable properties, including strong coagulation, adhesion to wet tissue, antibacterial activity, biosafety, ease of use, and stable storage, make QAL a promising emergency hemostatic agent.


Assuntos
Alginatos , Coagulação Sanguínea , Quitosana , Hemostáticos , Pós , Silicatos , Hemostáticos/química , Hemostáticos/farmacologia , Silicatos/química , Animais , Coagulação Sanguínea/efeitos dos fármacos , Pós/química , Quitosana/química , Alginatos/química , Alginatos/farmacologia , Humanos , Camundongos , Géis/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Hemostasia/efeitos dos fármacos
2.
Am J Physiol Cell Physiol ; 306(2): C152-66, 2014 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-24196530

RESUMO

Large-conductance Ca2(+)-activated K+ channels (BK) regulate action potential (AP) properties and excitability in many central neurons. However, the properties and functional roles of BK channels in parasympathetic cardiac motoneurons (PCMNs) in the nucleus ambiguus (NA) have not yet been well characterized. In this study, the tracer X-rhodamine-5 (and 6)-isothiocyanate (XRITC) was injected into the pericardial sac to retrogradely label PCMNs in FVB mice at postnatal 7-9 days. Two days later, XRITC-labeled PCMNs in brain stem slices were identified. Using excised patch single-channel recordings, we identified voltage-gated and Ca(2+)-dependent BK channels in PCMNs. The majority of BK channels exhibited persistent channel opening during voltage holding. These BK channels had a conductance of 237 pS and a 50% opening probability at +27.9 mV, the channel open time constant was 3.37 ms at +20 mV, and dwell time increased exponentially as the membrane potential depolarized. At the +20-mV holding potential, the [Ca2+]50 was 15.2 µM with a P0.5 of 0.4. Occasionally, some BK channels showed a transient channel opening and fast inactivation. Using whole cell voltage clamp, we found that BK channel mediated outward currents and afterhyperpolarization currents (IAHP). Using whole cell current clamp, we found that application of BK channel blocker iberiotoxin (IBTX) increased spike half-width and suppressed fast afterhyperpolarization (fAHP) amplitude following single APs. In addition, IBTX application increased spike half-width and reduced the spike frequency-dependent AP broadening in trains and spike frequency adaption (SFA). Furthermore, BK channel blockade decreased spike frequency. Collectively, these results demonstrate that PCMNs have BK channels that significantly regulate AP repolarization, fAHP, SFA, and spike frequency. We conclude that activation of BK channels underlies one of the mechanisms for facilitation of PCMN excitability.


Assuntos
Potenciais de Ação/fisiologia , Tronco Encefálico/citologia , Canais de Potássio Ativados por Cálcio de Condutância Alta/fisiologia , Neurônios Motores/fisiologia , Fibras Parassimpáticas Pós-Ganglionares/fisiologia , Pericárdio/fisiologia , Animais , Animais Recém-Nascidos , Tronco Encefálico/fisiologia , Músculos Laríngeos/citologia , Músculos Laríngeos/fisiologia , Masculino , Camundongos , Técnicas de Cultura de Órgãos , Faringe/citologia , Faringe/inervação , Faringe/fisiologia
3.
Int J Biol Macromol ; 254(Pt 2): 127821, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37926326

RESUMO

Excessive bleeding and bacterial infection leading to death is a major concern worldwide, particularly in cases of deep and narrow noncompressible hemorrhage. Herein, a novel Janus cryogel with anisotropic surface wettability, antibacterial activity, and rapid shape recovery was designed by constructing a hydrophilic porous cryogel using chitosan (CS), acacia gum (AG), and quaternized mesoporous bioglass (QMBG), with subsequent surface hydrophobic modification using octadecanol. The asymmetric hydrophobic surface modification of octadecanal endowed OCAQ with outstanding antiblood and antibacterial permeability, effectively preventing blood outflow and the invasion of bacteria to the wound. The hydrophilic parts with interconnected macroporous structure give the cryogel with ultra-high water uptake (5167 ± 182 %) and rapid water-trigged shape recover ability (≈2.1 s). The presence of active CS, AG, and QMBG in cryogel contributes to its exceptional blood clotting ability. Janus cryogel presents outstanding hemostatic performance (0.14 ± 0.03 g) in rat's liver injury model. Moreover, Janus cryogel exhibits excellent antibacterial properties due to the combination of its hydrophobic surface and antimicrobial quaternary amine groups. Meanwhile, the Janus cryogel has favorable hemocompatibility and biocompatibility. A Therefore, the Janus cryogel will become a candidate with great potential for clinical application of noncompressible wound as a multifunctional dressing.


Assuntos
Quitosana , Hemostáticos , Ratos , Animais , Quitosana/química , Criogéis/química , Molhabilidade , Cicatrização , Hemostasia , Hemostáticos/farmacologia , Hemostáticos/química , Antibacterianos/farmacologia , Antibacterianos/química , Hemorragia , Água/farmacologia
4.
Carbohydr Polym ; 333: 121998, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38494208

RESUMO

Hemostatic powders that adapt to irregularly shaped wounds, allowing for easy application and stable storage, have gained popularity for first-aid hemorrhage control. However, traditional powders often provide weak thrombus support and exhibit limited tissue adhesion, making them susceptible to dislodgment by the bloodstream. Inspired by fibrin fibers coagulation mediator, we have developed a bi-component hemostatic powder composed of positively charged quaternized chitosan (QCS) and negatively charged catechol-modified alginate (Cat-SA). Upon application to the wound, the bi-component powders (QCS/Cat-SA) rapidly absorb plasma and dissolve into chains. These chains interact with each other to form a network, which can effectively bind and entraps clustered red blood cells and platelets, ultimately leading to the creation of a durable and robust thrombus. Significantly, these interconnected polymers adhere to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from these synthetic properties, QCS/Cat-SA demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox™ in both arterial injuries and non-compressible liver puncture wounds. Importantly, QCS/Cat-SA exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of QCS/Cat-SA, including strong blood clotting, wet tissue adherence, antibacterial activity, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.


Assuntos
Quitosana , Hemostáticos , Trombose , Humanos , Fibrina , Adesivos/farmacologia , Coagulação Sanguínea , Hemostáticos/farmacologia , Quitosana/farmacologia , Polissacarídeos/farmacologia , Antibacterianos/farmacologia
5.
ACS Appl Mater Interfaces ; 16(9): 11263-11274, 2024 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-38404067

RESUMO

Hemostatic powder is commonly used in emergency bleeding control due to its suitability for irregularly shaped wounds, ease of use, and stable storage. However, traditional powder often has limited tissue adhesion and weak thrombus support, which makes it vulnerable to displacement by blood flow. Herein, we have developed a tricomponent hemostatic powder (MQS) composed of mesoporous bioactive glass nanoparticle (MBG), positively charged quaternized chitosan (QCS), and negatively charged catechol-modified alginate (SADA). Upon application to the wound, MBG with its high specific surface area quickly absorbs plasma, concentrating the blood coagulation factor. Simultaneously, the water-soluble QCS and SADA interact with each other and form a net, which can be further cross-linked by MBG. This network efficiently binds and entraps clustered blood coagulation factors, ultimately resulting in the formation of a durable and robust thrombus. Furthermore, the formed net adheres to the injury site, offering protection against thrombus disruption caused by the bloodstream. Benefiting from the synergistic effect of these three components, MQS demonstrates superior hemostatic performance compared to commercial hemostatic powders like Celox in both arterial injuries and noncompressible liver puncture wounds. Furthermore, MQS can effectively accelerate wound healing. In addition, MQS exhibits excellent antibacterial activity, cytocompatibility, and hemocompatibility. These advantages of MQS, including strong blood clotting, wet tissue adherence, antibacterial activity, wound healing ability, biosafety, ease of use, and stable storage, make it a promising hemostatic agent for emergency situations.


Assuntos
Quitosana , Hemostáticos , Trombose , Humanos , Pós/farmacologia , Hemostasia , Hemostáticos/farmacologia , Cicatrização , Quitosana/farmacologia , Biopolímeros/farmacologia , Antibacterianos/farmacologia
6.
Int J Biol Macromol ; 276(Pt 1): 133826, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39002908

RESUMO

Cotton gauze is commonly used in initial emergency care. However, its high hydrophilicity and limited clotting capacity can lead to the excessive absorption of blood, resulting in unnecessary blood loss. Herein, an amphiphilic Janus cotton gauze with excellent moisture management and enhanced blood coagulation has been developed via in situ generating bioactive glass (BG) onto the cotton gauze (CG), and then attaching cardanol (CA) onto one side of the BG-loaded CG (CG@BG) via click reaction. The Janus gauze (CA-CG@BG) has asymmetric wetting properties with a hydrophilic side (CA-CG@BGHL) and a hydrophobic side (HBCA-CG@BG). When applied to hemostatic, the porous and active BG on CA-CG@BGHL can rapidly initiate coagulation cascade to form a robust thrombus. CA on HBCA-CG@BG can entangled with each other, creating a hydrophobic barrier that prevents blood from flowing out. The hemostatic performance of CA-CG@BG is superior to that of CG in both rats and pigs. Interestingly, CA-CG@BG possesses unidirectional exudate removal. When applied to wound healing, the exudate can penetrate the hydrophobic HBCA-CG@BG to the hydrophilic CA-CG@BGHL, resulting in faster wound healing than CG. CA-CG@BG exhibits excellent cytocompatibility and hemocompatibility. This unique Janus dressing shows promise as a potential material for clinical applications in the future.


Assuntos
Bandagens , Coagulação Sanguínea , Hemostasia , Interações Hidrofóbicas e Hidrofílicas , Cicatrização , Animais , Cicatrização/efeitos dos fármacos , Coagulação Sanguínea/efeitos dos fármacos , Hemostasia/efeitos dos fármacos , Ratos , Fibra de Algodão , Hemostáticos/química , Hemostáticos/farmacologia , Suínos
7.
Adv Healthc Mater ; 13(13): e2303802, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38341630

RESUMO

Hydrogel is a very promising dressing for hemostasis and wound healing due to its good adhesion and long-term moist environment. However, secondary injury caused by tissue adhesion due to homogeneous hydrogel cannot be ignored. The obvious interface existing in Janus hydrogel will weaken its asymmetric function. Here, a hierarchical adhesive polyacrylic acid-polyurushiol water-oil Janus hydrogel (JPs@PAA-PU) without adhesive layer is fabricated by one-pot method in the stabilization of polystyrene@silica-siliver Janus particles (JPs). The morphological structure, mechanical properties, anisotropic chemical composition, and adhesion performance, in vivo, and in vitro hemostatic properties of Janus hydrogel are investigated. Result shows that the obtained Janus hydrogel possesses obvious compartmentalization in microstructure, functional groups, and chemical elements. Janus hydrogel is provided with asymmetric interfacial toughness with top 52.45 ± 2.29 Kpa and bottom 7.04 ± 0.88 Kpa on porcine liver. The adhesion properties of PAA side to tissue, red blood cells and platelets, promoting effect of PU side on coagulation cascade reaction and its physical battier endow Janus hydrogel with shorter hemostatic time and less blood loss than control group. It also exhibits excellent antibacterial effects against Escherichia coli and Staphylococcus aureus (>90%). Janus hydrogel possesses biosafety, providing safety guarantee for clinical applications in the future.


Assuntos
Resinas Acrílicas , Hidrogéis , Animais , Hidrogéis/química , Hidrogéis/farmacologia , Resinas Acrílicas/química , Escherichia coli/efeitos dos fármacos , Hemostasia/efeitos dos fármacos , Suínos , Hemostáticos/química , Hemostáticos/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Camundongos , Antibacterianos/química , Antibacterianos/farmacologia
8.
Adv Healthc Mater ; 13(19): e2400033, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38483196

RESUMO

Emergency prehospital wound closure and hemorrhage control are the first priorities for life-saving. Majority of bioadhesives form bonds with tissues through irreversible cross-linking, and the remobilization of misalignment may cause severe secondary damage to tissues. Therefore, developing an adhesive that can quickly and tolerably adhere to traumatized dynamic tissue or organ surfaces in emergency situations is a major challenge. Inspired by the structure of human serum albumin (HSA), a branched polymer with multitentacled sulfhydryl is synthesized, then, an instant and fault-tolerant tough wet-tissue adhesion (IFA) hydrogel is prepared. Adhesive application time is just 5 s (interfacial toughness of ≈580 J m-2), and favorable tissue-adhesion is maintained after ten cycles. IFA hydrogel shows unchangeable adhesive performance after 1 month of storage based on the internal oxidation-reduction mechanism. It not only can efficiently seal various organs but also achieves effective hemostasis in models of the rat femoral artery and rabbit-ear artery. This work also proposes an effective strategy for controllable adhesion, enabling the production of asymmetric adhesives with on-demand detachment. Importantly, IFA hydrogel has sound antioxidation, antibacterial property, hemocompatibility, and cytocompatibility. Hence, the HSA-inspired bioadhesive emerges as a promising first-aid supply for human-machine interface-based health management and non-invasive wound closure.


Assuntos
Hidrogéis , Adesivos Teciduais , Animais , Coelhos , Adesivos Teciduais/química , Adesivos Teciduais/farmacologia , Ratos , Humanos , Hidrogéis/química , Hidrogéis/farmacologia , Ratos Sprague-Dawley , Albumina Sérica Humana/química
9.
Int J Biol Macromol ; 270(Pt 2): 132440, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38761899

RESUMO

Hemostatic powder is widely utilized in emergency situations to control bleeding due to its ability to work well on wounds with irregular shapes, ease of application, and long-term stability. However, traditional powder often suffers from limited tissue adhesion and insufficient support for blood clot formation, leaving it susceptible to displacement by the flow of blood. This study introduces a hemostatic powder composed of tannic modified mesoporous bioactive glass (TMBG), cationic quaternized chitosan (QCS), and anionic hyaluronic acid modified with catechol group (HADA). The resulting TMBG/QCS/HADA based hemostatic powder (TMQH) rapidly absorbs plasma, concentrating blood coagulation factors. Simultaneously, the water-soluble QCS and HADA interact to form a 3D network structure, which can be strengthened by crosslinking with TMBG. This network effectively captures clustered blood coagulation factors, leading to a strong and adhesive thrombus that resists disruption from blood flow. TMQH exhibits superior efficacy in promoting hemostasis compared to Celox™ both in rat arterial injuries and non-compressible liver puncture wounds. TMQH demonstrates excellent antibacterial activity, cytocompatibility, and blood compatibility. These outstanding superiorities in blood clotting capability, wet tissue adhesion, antibacterial activity, safety for living organisms, ease of application, and long-term stability, make TMQH highly suitable for emergency hemostasis.


Assuntos
Coagulação Sanguínea , Hemostáticos , Pós , Taninos , Animais , Ratos , Coagulação Sanguínea/efeitos dos fármacos , Taninos/química , Taninos/farmacologia , Hemostáticos/química , Hemostáticos/farmacologia , Porosidade , Vidro/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Quitosana/química , Quitosana/farmacologia , Géis/química , Humanos , Adesivos/química , Adesivos/farmacologia , Masculino , Ratos Sprague-Dawley , Hemostasia/efeitos dos fármacos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia
10.
Nat Commun ; 14(1): 6586, 2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37852967

RESUMO

Additive manufacturing technology has significantly impacted contemporary industries due to its ability to generate intricate computer-designed geometries. However, 3D-printed polymer parts often possess limited application potential, primarily because of their weak mechanical attributes. To overcome this drawback, this study formulates liquid crystal/photocurable resins suitable for the stereolithography technique by integrating 4'-pentyl-4-cyanobiphenyl with a photosensitive acrylic resin. This study demonstrates that stereolithography facilitates the precise modulation of the existing liquid crystal morphology within the resin. Furthermore, the orientation of the liquid crystal governs the oriented polymerization of monomers or prepolymers bearing acrylate groups. The products of this 3D printing approach manifest anisotropic behavior. Remarkably, when utilizing liquid crystal/photocurable resins, the resulting 3D-printed objects are approximately twice as robust as those created using commercial resins in terms of their tensile, flexural, and impact properties. This pioneering approach holds promise for realizing autonomously designed structures that remain elusive with present additive manufacturing techniques.

11.
J Mater Chem B ; 10(45): 9413-9423, 2022 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-36377727

RESUMO

It is of utmost importance that bleeding should be stopped and infection be prevented in people with trauma. In this study, an anisotropic Janus mesoporous silica nanosheet (MSNS) with different functional groups was designed and prepared. In order to endow both sides of the MSNS with independent fast hemostasis and effective antibacterial action, the MSNS was modified with cardanol (CA) and 2,3-epoxypropyltrimethylammonium (GTA). The addition of CA significantly improved the hemostatic property of the MSNS. In a SD rat femoral artery injury model, the hemostatic time of CA-MSNS-GTA was 47% shorter than that of the MSNS, attributed to the sealing of the hydrophobic alkyl side chain and the adhesion of phenolic hydroxyl groups in CA. CA-MSNS-GTA could form a three-dimensional network with fibrin to further accelerate the coagulation process. This Janus material exhibited excellent antibacterial effects (∼90%) against Gram-positive bacteria (S. pneumoniae) and Gram-negative bacteria (E. coli) due to the presence of GTA. The cytotoxicity test showed that CA-MSNS-GTA exhibited biosafety, which provided safety guarantee for clinical applications in the future. This Janus dressing with different functions on two opposite sides provides synergetic multifunctional effects during wound healing.


Assuntos
Hemostáticos , Ratos , Animais , Hemostáticos/farmacologia , Escherichia coli , Ratos Sprague-Dawley , Dióxido de Silício/química , Bandagens , Antibacterianos/farmacologia , Antibacterianos/química , Compostos de Amônio Quaternário/farmacologia , Coagulação Sanguínea
12.
Int J Infect Dis ; 115: 245-255, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34910955

RESUMO

BACKGROUND: The aim of this study was to evaluate the long-term sequelae and cognitive profiles resulting from severe hand, foot, and mouth disease (HFMD) with central nervous system (CNS) involvement. METHODS: 294 HFMD cases were included in a retrospective follow-up study. Physical examinations were conducted. The Chinese Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV) was used to assess intelligence. RESULTS: 58 mild HFMD cases and 99 severe HFMD cases with mild CNS involvement did not present any neurological sequelae. In comparison, the sequelae incidence for severe HFMD with more severe CNS complications was 50.0%. The proportion of full-scale intelligence quotient (FSIQ) impairment was 45.0%. In the 2:6-3:11 age group, severe HFMD with more severe CNS complications and lower maternal education level were risk factors for verbal comprehension disorder. Urban-rural residence and lower paternal education level were risk factors for FSIQ disorder. Furthermore, in the 4:0-6:11 age group, severe HFMD with more severe CNS complication was a risk factor for visual spatial disorder and fluid reasoning disorder. Lower paternal education level was a risk factor for FSIQ disorder. CONCLUSION: Early assessment and intervention among severe HFMD patients with more severe CNS involvement at a very young age will prove beneficial for their future performance.


Assuntos
Doença de Mão, Pé e Boca , Pré-Escolar , China/epidemiologia , Seguimentos , Doença de Mão, Pé e Boca/complicações , Doença de Mão, Pé e Boca/epidemiologia , Humanos , Incidência , Lactente , Estudos Retrospectivos
13.
Mater Sci Eng C Mater Biol Appl ; 123: 111958, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33812586

RESUMO

It is important to control bleeding and prevent bacterial infection for the wound people. The effective way is to fabricate an asymmetric Janus matrial for realizing rapid hemostasis and promoting wound healing. Herein, mesoporous silica nanoparticles (MSN) modified by tannic acid (TA), silver nanoparticles, and calcium ions (Ca-TA-MSN@Ag) with Janus structure were prepared via redox and coordination reactions. These anisotropic snowman-like particles possess obvious chemical compartition, in which silver nanoparticles are embedding in large MSN body. During blood coagulation, TA with catechol structure acts as a vasoconstrictor. Then, Ca-TA-MSN@Ag with high specific surface area (510.62 m2·g-1) and large pore volume (0.48 m3·g-1) induces red blood cell aggregation to form three-dimensional network structure with fibrin. Additionally, calcium ions as clotting factor IV and negative charge of Ca-TA-MSN@Ag accelerate coagulation cascade reaction. These three synergistic effects on animal model showed that hemostatic time of Ca-TA-MSN@Ag was shortened by nearly 50% compared to that of MSN. Moreover, Ca-TA-MSN@Ag possessed good blood compatibility, biocompatibility and antibacterial activity (~99%) against E. coli and S. aureus. The anisotropic Janus particles of Ca-TA-MSN@Ag with hemostatic performance and antibacterial activity will be a promising biomaterial for designing wound dressings in clinical application.


Assuntos
Nanopartículas Metálicas , Nanopartículas Multifuncionais , Nanopartículas , Animais , Antibacterianos/farmacologia , Cálcio , Escherichia coli , Hemostasia , Dióxido de Silício , Prata/farmacologia , Staphylococcus aureus , Taninos/farmacologia
14.
Colloids Surf B Biointerfaces ; 207: 112028, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34388612

RESUMO

The anisotropic Janus gel shows more diverse characteristic and responsiveness due to its asymmetric chemical structure. Herein, the water/oil PDA-PAA/PBMA-PEHMA Janus gel was prepared by one-step polymerization of incompatible monomers. In this Janus gel, PDA-PAA layer possesses good adhesion effect and self-healing property attributing to the chemical bonds and the hydrogen bonds among DA, AA, or each other, and the π-π stacking of DA. The IPN structure of the water phase and the oil phase makes Janus gel have good mechanical properties. The above chemical and physical effects dissipate a large amount of energy when PDA-PAA/PBMA-PEHMA Janus gel is subjected to external forces, so it has excellent fatigue resistance. The hydrophilic PDA-PAA side and the lipophilic PBMA-PEHMA side show different swelling responses in the oil-water medium. The internal stress difference caused by this different swelling makes the Janus gel show curl toward different directions in different media. Then, conductivity media of NaCl added in PDA-PAA layer endows Janus gel with anisotropic conductivity. It is possible to judge the hydrophilic and hydrophobic properties of solution by monitoring the current change of conductive Janus gel. Conductive Janus gel can also be used to monitor human body motion and micro motion. This conductive/insulating Janus gel is suitable for flexible sensor used in harsh environment.


Assuntos
Adesivos , Anisotropia , Meios de Cultura , Condutividade Elétrica , Humanos , Ligação de Hidrogênio
15.
ACS Appl Mater Interfaces ; 13(43): 51546-51555, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34689543

RESUMO

Sensors based on conductive hydrogels have received extensive attention in various fields, such as artificial intelligence, electronic skin, and health monitoring. However, the poor resilience and fatigue resistance, icing, and water loss of traditional hydrogels greatly limit their application. Herein, an ionic conductive organohydrogel (PAC-Zn) was prepared for the first time by copolymerization of cardanol and acrylic acid in water/1,3-butanediol as a binary solvent system. A very small amount of cardanol (1% cardanol of total monomers) could not only significantly improve the tensile strength (∼4 times) and toughness (∼3 times) of PAA but also improve its extensibility. Due to the presence of 1,3-butanediol, PAC-Zn showed outstanding tolerance for freezing (-45 °C) and drying (over 85% moisture retention after 15 days of storage in a 37 °C oven). Compared with ethylene glycol and glycerol as antifreeze agents used in organohydrogels, the addition of 1,3-butanediol endowed the organohydrogel with not only similar frost resistance but also better mechanical performance. Besides, PAC-Zn exhibited fast resilience (almost no hysteresis loop) and excellent antifatigue ability. More importantly, a PAC-Zn organohydrogel-based sensor could detect human motion in real time (wrist, elbow, finger, and knee joints), revealing its fast response, good sensitivity, and stable electromechanical repeatability. In conclusion, the multifunctional PAC-Zn organohydrogel is expected to become a potential and promising candidate in the field of strain sensors under a broad range of environmental temperatures.


Assuntos
Inteligência Artificial , Hidrogéis/química , Compostos Organometálicos/química , Fenóis/química , Dispositivos Eletrônicos Vestíveis , Zinco/química , Condutividade Elétrica , Humanos
16.
J Nanosci Nanotechnol ; 21(9): 4792-4796, 2021 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-33691868

RESUMO

The presence of malachite green dye in wastewater has a great negative impact on the environment. At present, industrial wastewater is treated using adsorption, electrolysis and membrane separation, among which the adsorption method is the most widely used wastewater treatment. In this study mesoporous silica nanoparticles (MSNs) were prepared using the sol-gel method and modified with the natural polymer urushiol (U) to obtain MSN@Us, which have a core-shell structure. This is the first use of urushiol in dye adsorption. The structures and chemical properties of the MSNs and MSN@Us were characterized. The adsorption of malachite green by the MSNs and MSN@Us showed that the adsorption rate of MSN@Us was higher than that of MSNs, with an adsorption rate greater than 90%. This study provides a new research direction for the use of urushiol in the treatment of contaminated wastewater.


Assuntos
Nanopartículas , Dióxido de Silício , Adsorção , Catecóis , Porosidade , Corantes de Rosanilina
17.
Am J Physiol Cell Physiol ; 299(6): C1285-98, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20739619

RESUMO

Small conductance Ca(2+)-activated K(+) channels (SK) regulate action potential (AP) firing properties and excitability in many central neurons. However, the functional roles of SK channels of parasympathetic cardiac motoneurons (PCMNs) in the nucleus ambiguus have not yet been well characterized. In this study, the tracer X-rhodamine-5 (and 6)-isothiocyanate (XRITC) was injected into the pericardial sac to retrogradely label PCMNs in FVB mice at postnatal days 7-9. Two days later, XRITC-labeled PCMNs in brain stem slices were identified. With the use of whole cell current clamp, single APs and spike trains of different frequencies were evoked by current injections. We found that 1) PCMNs have two different firing patterns: the majority of PCMNs (90%) exhibited spike frequency adaptation (SFA) and the rest (10%) showed less or no adaptation; 2) application of the specific SK channel blocker apamin significantly increased spike half-width in single APs and trains and reduced the spike frequency-dependent AP broadening in trains; 3) SK channel blockade suppressed afterhyperpolarization (AHP) amplitude following single APs and trains and abolished spike-frequency dependence of AHP in trains; and 4) SK channel blockade increased the spike frequency but did not alter the pattern of SFA. Using whole cell voltage clamp, we measured outward currents and afterhyperpolarization current (I(AHP)). SK channel blockade revealed that SK-mediated outward currents had both transient and persistent components. After bath application of apamin and Ca(2+)-free solution, we found that apamin-sensitive and Ca(2+)-sensitive I(AHP) were comparable, confirming that SK channels may contribute to a major portion of Ca(2+)-activated K(+) channel-mediated I(AHP). These results suggest that PCMNs have SK channels that significantly regulate AP repolarization, AHP, and spike frequency but do not affect SFA. We conclude that activation of SK channels underlies one of the mechanisms for negative control of PCMN excitability.


Assuntos
Coração/inervação , Coração/fisiologia , Bulbo/fisiologia , Neurônios Motores/fisiologia , Sistema Nervoso Parassimpático/fisiologia , Canais de Potássio Ativados por Cálcio de Condutância Baixa/fisiologia , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Apamina/farmacologia , Feminino , Masculino , Camundongos , Canais de Potássio Ativados por Cálcio de Condutância Baixa/efeitos dos fármacos
18.
ACS Appl Bio Mater ; 3(12): 9054-9064, 2020 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35019582

RESUMO

Janus particles with obvious chemical compartition can perform their functions independently, so they have attracted much attention in biomedical materials. Herein, a mesoporous silica/silver Janus nanoparticle modified with cardanol (C-MSN@Ag) was designed and synthesized via redox and click chemical reactions and was further evaluated as a highly efficient hemostatic dressing. This Janus structure endowed C-MSN@Ag with both prominent hemostatic and antibacterial performance. The hemostatic time of C-MSN@Ag on rat liver laceration was up to 40% shorter than that of MSN and MSN@Ag because of adhesion of phenolic compounds on the tissue and the blocking effect of the hydrophobic alkyl chains from cardanol. Besides, C-MSN@Ag could promote coagulation by forming a three-dimensional network with fibrin more quickly than MSN and MSN@Ag. Additionally, due to the released silver ions and phenolic hydroxyl groups of cardanol, C-MSN@Ag exhibited a broad-spectrum antibacterial rate (∼99%) against both Escherichia coli and Staphylococcus aureus. C-MSN@Ag also possessed non-cytotoxicity. This work not only provides a way for the fabrication of silica-based Janus hemostatic agents by the atom-economical click reaction but also gives a direction for the application of the sustainable naturally occurring cardanol.

19.
Int J Biol Macromol ; 139: 1203-1211, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31415855

RESUMO

The powder hemostatic materials are increasingly appreciated because of their long storage time, wide storage temperature, portable property, especially their use both in vivo and epidermis. Mesoporous silica materials attracted more and more attention owing to their favorable biocompatibility and outstanding hemostatic performance, but their hemostatic process was too simple to meet the requirements. Herein, mesoporous silica nanoparticles modified by chitosan and hydrocaffeic acid (MSN@CS-HCA) were developed for rapid and safe hemorrhage control. By tissue adhesion, activating the coagulation cascade, aggregating red blood cells and platelets, MSN@CS-HCA with the porous network exhibited excellent hemostatic effects in both in vivo and in vitro coagulation tests. The hemostatic time of MSN@CS-HCA was 60.3% shorter than that of MSN in femoral artery trauma models of SD rats. Besides, MSN@CS-HCA with good biocompatibility and ability to promote wound healing, could form the network structure with fibrin in the blood, which enhanced the mechanical strength of the blood clot and acted as a physical barrier to prevent blood loss. In conclusion, MSN@CS-HCA will be a potential and prospective hemostatic dressing for the control of hemorrhage in more extensive clinical application future.


Assuntos
Ácidos Cafeicos/química , Quitosana/química , Hemostáticos/química , Hemostáticos/farmacologia , Dióxido de Silício/química , Dióxido de Silício/farmacologia , Animais , Coagulação Sanguínea/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Eritrócitos/citologia , Eritrócitos/efeitos dos fármacos , Artéria Femoral/efeitos dos fármacos , Artéria Femoral/fisiologia , Cinética , Lacerações/fisiopatologia , Fígado/efeitos dos fármacos , Fígado/fisiopatologia , Porosidade , Ratos , Ratos Sprague-Dawley
20.
ACS Omega ; 4(18): 17607-17614, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31681867

RESUMO

The inorganic particles used as a compatibilizer play a role in crack termination and heat resistance. However, the poor compatibility of inorganic particles and polymer hinders their application. Herein, the double spherical SiO2@PDVB Janus particles (JPs) were modified with triethylenetetramine (TETA), and the obtained anisotropic TETA-SiO2@PDVB JPs were used as the compatibilizer of acrylic resin/epoxy resin (AR/EP) composites. The modification and the compatibilization of TETA-SiO2@PDVB JPs were studied by scanning electron microscopy, X-ray photoelectron spectroscopy, differential scanning calorimetry, and dynamic mechanical analyzer, impact test, tensile test, and so forth. Results show that amino groups grafted onto the SiO2 lobe can react with epoxy groups of EP, which results in the TETA-SiO2 lobe being embedded in the EP phase and the PDVB lobe being pushed toward the AR phase. The TETA-SiO2@PDVB JPs anchored at the interface of AR and EP increase their interfacial adhesion, decrease the domain phase size and distribution of dispersed AR, and improve the compatibility of AR/EP composites. The compatibilization of nanoparticles (NPs) is realized by the cavitation and blunting of different scaled AR phase domain distributions and that of JPs is realized by the strong interfacial force originated by JPs. Moreover, the desorption energy of TETA-SiO2@PDVB JPs is higher than that of SiO2-TETA; so the glass transition temperature (T g) of AR/EP/JP composites is higher than that of AR/EP/NP composites. The strong interfacial adhesion and high desorption energy endow TETA-SiO2@PDVB JPs with a toughening effect and enhancing effect. The impact strength and the tensile strength of AR/EP/TETA-SiO2@PDVB composites are 16.03 kJ/m2 and 63.12 MPa, which are 9.91 kJ/m2 and 16.32 MPa higher than those of AR/EP composites, respectively. JPs used in the thermosetting EP is benefit to its toughening study and the new anisotropic Janus compatibilizer.

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