查找使用阿拉丁产品的科研文献

Preparation and evaluation of SiO2-deposited stearic acid-g-chitosan nanoparticles for doxorubicin delivery

Hong Yuan,Xin Bao,Yong-Zhong Du,Jian You,Fu-Qiang Hu

Laccase-Triggered Surface Co-Deposition of Gentisic Acid and Chitosan for Multifunctional Polymer Membranes

Wen-Ying Yang,Di Zhou,Jia-Lu Shen,Zhi-Kang Xu,Ling-Shu Wan

Co-deposition of phenols and amines inspired by mussel-inspired chemistry has attracted much attention in the field of surface and interface science and technology. However, most deposition systems are still limited to phenols with at least one catechol group. In this work, a novel enzyme-triggered co-deposition system based on a natural phenol (gentisic acid, GA) and a kind of biomacromolecule (chitosan, CS) is reported. With the catalysis of laccase, GA can be oxidized and further react with CS to form effective surface coatings on various substrates such as polypropylene microfiltration membrane (PPMM). The co-deposition process takes only 40 min at room temperature and endows the membrane with superhydrophilicity and underwater superoleophobicity. The modified membranes show excellent separation performance, reusability, and long-term stability for the separation of oil-in-water emulsions. The modified membranes are highly charged (pI ≈7.2) and capable of efficient dye adsorption. In addition, the modified membranes possess better protein resistance properties compared with the nascent membranes. This work demonstrates a green, mild, and highly efficient surface modification process based on laccase catalysis. The co-deposition system comes from natural sources and expands the phenol family for constructing multi-functional surface coatings.

Antifouling modification of PVDF membranes via incorporating positive-charge tuned quaternized chitosan magnetic particles

Ziming Zhu,Xuan Zhou,Rui Zhang,Yahong Li,Yuan Liu,Jianxian Zeng,Xiaoping Huang,Pengfei Liu,Jianrong Xue,Kaipeng Cheng,Hongfei Xu

Membrane separation technology often suffers from fouling during operation and undergoes a trade-off effect between permeability and selectivity . We report a new strategy for fabricating antifouling poly(vinylidene fluoride) (PVDF) ultrafiltration membrane by incorporating hydrophilic, positive-charge tuned quaternized chitosan magnetic particles (QCMP). Fe 3 O 4 -chitosan particles were synthesized by co-precipitation and cross-linked by glutaraldehyde, and further quaternization modification was applied to obtain a series of QCMP with different charge densities. Then, the QCMP were incorporated into the matrix of PVDF to prepare hybrid membrane via the non-solvent-induced phase separation method. The effect of incorporated QCMP on the membrane morphology and properties was determined using scanning electron microscopy, water contact angle, surface free energy , membrane pore size and porosity. The incorporation of QCMP into the PVDF membrane effectively increased the surface hydrophilicity. Results of bovine serum albumin (BSA) solution filtration showed a higher flux recovery ratio (FRR) and a lower total fouling ratio(R t ) of the QCMP/PVDF hybrid membranes than those of the PVDF pristine membrane, indicating the addition of QCMP was helpful to enhance antifouing performance for BSA via improving hydrophilicity and neutralizing the surfaces of negatively charged PVDF membranes. Furthermore, the permeability flux of BSA was increased by 53 % and the rejection rate was also increased by 26 %, indicating the hybrid membranes have the potential to break the permeability-selectivity trade-off. Therefore, this study provided a green, simple and effective method for the rational design and construction membranes with enhanced the permeability and selectivity as well as antifouling performance.

Nanocomposite pastes of gelatin and cyclodextrin-grafted chitosan nanoparticles as potential postoperative tumor therapy

Xiao Lin,Xu Weichang,Huang Lixia,Liu Jili,Yang Guang

Effective postoperative therapy is crucial for preventing tumor recurrence and metastasis. Nanocomposite (NC) pastes of Gel/CS-g-CD NP with unique viscoelastic properties and pH-responsive drug delivery ability were prepared from gelatin (Gel) and β-cyclodextrin-grafted chitosan nanoparticles (CS-g-CD NPs) through host–guest interactions between the aromatic amino acid residues of gelatin and β-cyclodextrin. The dynamic rheological properties, shear strength, and shear viscosity were modulated through variations in the concentration of CS-g-CD NPs in the NC pastes. Due to the reversibility of the host–guest interactions, the NC pastes exhibited shear-thinning and self-healing properties, endowing them with good injectability. Loading of doxorubicin (DOX) in the nanoparticles (DOX-CSCD NPs) forming the NC pastes of Gel/DOX-CSCD NP allowed pH-triggered DOX release in a simulated tumoral microenvironment, because of the labile nature of the CS-g-CD NPs under acidic conditions. In vitro experiments showed that the NC pastes of Gel/DOX-CSCD NP induced sustained tumor cell inhibition. Moreover, in vivo studies with tumor-bearing mice indicated that the NC pastes of Gel/DOX-CSCD NP can effectively inhibit tumor recurrence after surgical resection. Therefore, the NC pastes described in this work may act as an effective injectable drug delivery system for postoperative tumoral treatment.

A self-gelling powder based on polyacrylic acid/polyacrylamide/quaternate chitosan for rapid hemostasis

Zhouying Tan,Xi Li,Chaojie Yu,Mengmeng Yao,Zhongming Zhao,Bingyan Guo,Lei Liang,Yuping Wei,Fanglian Yao,Hong Zhang,Junjie Li

In order to improve the hemostatic effect of the hemostatic dressing for non-compressible wounds, unknown bleeding points and irregularly shaped wounds, a self-gelling hemostasis powder based on polyacrylic acid/polyacrylamide/quaternate chitosan (PAA/PAM/QCS) is prepared in this study. When in contact with water, the PAA/PAM/QCS can fuse and rapidly form a stable hydrogel in a short time (< 0.25 min). The PAA/PAM ratio is the main parameter that modulates the formation of the self-gel. The PAA/PAM self-gel can be formed only when the PAA/PAM ratio is 5:5, and the introduction of QCS does not influence the self-gelling behaviors and hydrogel stability. Moreover, the PAA/PAM/QCS self-gel shows good adhesive properties on wet tissue surfaces. In addition, the introduction of QCS improves the antibacterial activity of the self-gelling hemostasis powder. Furthermore, the prepared PAA/PAM/QCS powder can rapidly adsorb lots of blood, aggregate blood cells and platelets. The hemostatic results in vivo show that PAA/PAM/QCS powder is superior to the control group and commercial product groups (chitosan powder) with performance similar to hemostatic zeolite in terms of the amount of bleeding and hemostatic time. Therefore, the PAA/PAM/QCS self-gelling powder shows great application prospects for rapid hemostasis.

Poly β-Cyclodextrin/Quaternary Ammoniated Chitosan Cryogel with a Porous Structure for Effective Hemostasis

Min Tan,Fan Liu,Li-Guo Liao,Jun-Feng Feng,Fu-Zhong Zhang,Shu-Ting Fan,Jia-Xin Wang,Kun Guo,Bang-Jing Li,Sheng Zhang

Uncontrolled bleeding is one of the most important causes threatening human health, but quick hemostasis remains a challenge. We prepared porous cryogels with poly β-cyclodextrin (Pβ-CD) and quaternary ammoniated chitosan (QCs). Pβ-CD acts as a “water-grabbing agent” to assist QCs’ ability to absorb and concentrate blood rapidly. The rat-tail amputation model and liver injury model exhibited that cryogels had excellent hemostatic performance. Moreover, cryogels showed good antibacterial activity and biocompatibility. Therefore, these cryogels can be used as potential hemostatic materials.

Injectable carboxymethyl chitosan-based hydrogel for simultaneous anti-tumor recurrence and anti-bacterial applications

Yang Yu,Xiaoyi Zheng,Xiuying Liu,Jiulong Zhao,Shige Wang

The postoperative recurrence has adversely affected the treatment of tumors. Besides, the potential bacterial infection at the wound site may lead to a series of tissue necrosis. Here, we developed an injectable γ-polyglutamic acid/carboxymethyl chitosan/polydopamine hydrogel (PCP) for simultaneously reducing the postoperative infection and preventing the tumor recurrence. On the one hand, the aqueous solution of carboxymethyl chitosan oxidized the dopamine into polydopamine; on the other, the carboxymethyl chitosan was cross-linked with the activated γ-polyglutamic acid to form a hydrogel. After local implantation, the PCP hydrogel effectively killed tumor cells and bacteria under 808 nm laser irradiation. In addition, carboxymethyl chitosan rendered the hydrogel with anti-bacterial properties as well as anti-tumor efficiencies. The anti-tumor recurrence and anti-bacterial efficiencies of PCP hydrogel were proved on a tumor-removed mouse model and a Staphylococcus aureus -infected mouse model, respectively. Moreover, the hydrogel has the advantages of good biocompatibility and simple preparation, and thus has potential application prospects in the prevention of tumor recurrence and wound bacterial infection.

A novel cationic-modified chitosan flocculant efficiently treats alkali‒surfactant‒polymer flooding-produced water

Zhang Dawei,Wang Jiaming,Ren Lu,Meng Xiangchun,Luan Boyi,Zhang Yumin

The existence of fine oil droplets that are difficult to coalesce greatly reduces the oil–water separation efficiency of alkali‒surfactant‒polymer (ASP) flooding-produced water. In order to improve the oil–water separation efficiency and promote the reinjection of ASP-produced water, a novel cationic graft copolymer CDC was obtained by ultrasonically assisted copolymerization of chitosan and dimethyl diallyl ammonium chloride under the initiation of cerium ions. The copolymer CDC was characterized by FT-IR, XRD, TGA and SEM, and it was confirmed that the grafting reaction proceeded successfully. The flocculation effect of copolymer CDC on ASP-produced water (Nan 4–8, pH = 7.83; Sanyuan-6, pH = 9.95) was investigated. Copolymer CDC has better oil removal rate (90.5%) and light transmittance (95.25%) to Nan 4–8 produced water compared with Sanyuan-6-produced water. It has a better oil removal effect when the initial pH of produced water is 6–7 and the temperature is 30 °C. After the addition of CDC, the large-diameter oil droplets in produced water will coalesce and separate. It may be that under weak acid or neutral conditions, the electrostatic attraction of produced water is enhanced, compressing the double electron layer of oil droplets, and destroying the stability of oil droplets. In addition, the hydrophobic effect of –CH=CH 2 in CDC molecules increases the hydrophobic association between molecules and increases the probability of oil droplet collision during the flocculation process.

Chitosan-derived carbon supported CoO combined with CdS facilitates visible light catalytic hydrogen evolution

Peijing Guo,Shaoyu Yuan,Bingrong Guo,Siwei Li,Yongjun Gao

A CoO–CdS heterostructured photocatalyst CC-2-300 loaded with carbon derived from the biomass material chitosan was synthesized. Under visible-light irradiation, the photocatalytic hydrogen evolution rate can reach up to 10.60 mmol gcat−1 h−1, which is 7.21 times higher than that of pure CdS under the same conditions, with good cycle stability and high apparent quantum efficiency. The control experiments and characterization results prove that the chitosan-derived carbon supported CoO nanorods and CdS nanoparticles are cross-distributed to form a direct Z-scheme heterojunction, which improves the migration efficiency of photogenerated carriers and effectively slows down the recombination rate of photogenerated charges and holes on CdS that is susceptible to photocorrosion, thus improving the efficiency of photocatalytic hydrogen evolution.

Electroactive injectable hydrogel based on oxidized sodium alginate and carboxymethyl chitosan for wound healing

Lin Zhao,Zhipan Feng,Yang Lyu,Jueying Yang,Lizhi Lin,Haochen Bai,Yujing Li,Yongqiang Feng,Yu Chen

Electroactive hydrogel is of great significance in restoring wound currents, promoting cell proliferation, and accelerating the wound healing process. However, the poor dispersity and underlying toxicity of electronic conductive fillers and high concentration of ionic conductors in traditional electroactive hydrogel limited its application in medical care. Herein, an electroactive oxidized sodium alginate/carboxymethyl chitosan/silver nanoparticles (OSA/CMCS/AgNPs) hydrogel was constructed with no additional conductive fillers or synthesized conductive polymers being added, in which the dynamic imine bonds were rapidly formed between aldehyde groups in OSA and amino groups in CMCS, and AgNPs were further in situ formed by UV irradiation. The electroactive hydrogel exhibited the injectable property, strong self-healing ability, excellent biocompatibility, and high antibacterial activities. Moreover, the electroactive hydrogel can significantly promote the proliferation of L929 cells under electrical stimulation. Furthermore, the electroactive hydrogel was proved to significantly accelerate the wound healing process in the full-thickness skin defect model, exhibiting anti-inflammation, promoting the fibroblasts proliferation, angiogenesis, and collagen deposition under electrical stimulation. In summary, the current work explored a novel strategy to construct the polysaccharides-based electroactive hydrogel with good biocompatibility and multi-functions, which is promising to be used in deep wound treatment.

Carbon Quantum Dot/Chitosan-Derived Hydrogels with Photo-stress-pH Multiresponsiveness for Wearable Sensors

Xiaotong Wei,Jie Li,Zhirui Hu,Chen Wang,Zhiqiang Gao,Yang Cao,Jing Han,Yingchun Li

In recent years, hydrogels have attracted extensive attention in smart sensing owing to their biocompatibility and high elasticity. However, it is still a challenge to develop hydrogels with excellent multiple responsiveness for smart wearable sensors. In this paper, a facile synthesis of carbon quantum dots (CQDs)-doped cross-linked chitosan quaternary/carboxymethylcellulose hydrogels (CCCDs) is presented. Designing of dual network hydrogels decorated with CQDs provides abundant crosslinking and improves the mechanical properties of the hydrogels. The hydrogel-based strain sensor exhibits excellent sensitivity (gauge factor: 9.88), linearity ( R 2 : 0.97), stretchable ability (stress: 0.67 MPa; strain: 404%), good cyclicity, and durability. The luminescent properties are endowed by the CQDs further broaden the application of hydrogels for realizing flexible electronics. More interestingly, the strain sensor based on CCCDs hydrogel demonstrates photo responsiveness (Δ R / R 0 ≈20%) and pH responsiveness (pH range ≈4–7) performance. CCCDs hydrogels can be used for gesture recognition and light sensing switch. As a proof-of-concept, a smart wearable sensor is designed for monitoring human activities and detecting pH variation in human sweat during exercise. This study reveals new possibilities for further applications in wearable health monitoring.

Essential oil-loaded chitosan/zinc (II) montmorillonite synergistic sustained-release system as antibacterial material

Jinghui Zhan,Huayao Chen,Hongjun Zhou,Li Hao,Hua Xu,Xinhua Zhou

Tea tree oil (TTO) is a broad-spectrum natural antimicrobial agent. Its application is limited due to its volatile property. To reduce its volatility and improve its sustained-release performance, a synergistic sustained-release system was prepared. Montmorillonite (Mt) was ion-exchanged with sodium ions (Na+) and zinc ions (Zn2+), then organically modified with cetyl trimethyl ammonium bromide (CTAB) and chitosan (CS) to improve its sustained release performance. The results indicated that Mt was exfoliated, but still maintained its ordered layer structure. The surface of CS-Zn-OMt was rough, because some pores and surfaces were filled. The addition of Zn2+ increased the loading of CS (37.8 − 40.8%) and induced more uniform distribution of CS on Mt. Also, CS-Zn-OMt achieved a high loading capacity for TTO and the loading value was 222.0 mg*g−1. Furthermore, the release studies showed that CS-Zn-OMt exhibited sustained-release behavior due to the release from the outer layer of CS and the Mt channel simultaneously. The results of antibacterial test showed that the addition of CS inhibited the drift of Mt and showed good antibacterial performance because of strong effective drug-carrier interaction. The developed system can be potentially applied for the delivery of volatile essential oils for antibacterial infection.