查找使用阿拉丁产品的科研文献

Multifunctional PCL composite nanofibers reinforced with lignin and ZIF-8 for the treatment of bone defects

Rongtao Liu,Yiyu Pang,Tianhua Xiao,Shiyang Zhang,Yidong Liu,Yonggang Min

Polycaprolactone (PCL) nanofibers have become an ideal material for bone tissue engineering due to a series of advantages. Considering the clinical treatment of bone defects, in addition to meeting the golden standard, PCL based nanofibers also need to be multifunctional to anti-inflammatory, antibacterial properties, and enhance the bone regeneration and repair. Herein, we successfully developed the multifunctional PCL/LIG/ZIF-8 composite nanofibers by loading ZIF-8 on electrospun PCL/lignin (PCL/LIG) nanofibers. The prepared composite nanofibers exhibit fairly good wettability and acceptable degradation rate, as well as excellent antioxidative stress and antibacterial properties originating from the incorporated LIG and loaded ZIF-8. Moreover, owing to the synergistic effect of LIG and ZIF-8, the composite nanofibers present excellent osteogenic differentiation, which can be verified in biomineralization experiments and real-time quantitative polymerase chain reaction. These results indicate that the PCL/LIG/ZIF-8 composite nanofibers, as potential healthcare candidate, have a promising applied in the treatment of bone defects.

Chitosan/PCL nanofibrous films developed by SBS to encapsulate thymol/HPβCD inclusion complexes for fruit packaging

Chaoyi Shen,Menglu Wu,Cui Sun,Jiangkuo Li,Di Wu,Chongde Sun,Yong He,Kunsong Chen

In this work, the solution blow spinning (SBS) technique was used to rapidly fabricate the thymol (THY)/2-hydroxypropyl-β-cyclodextrin (HPβCD) inclusion complexes loaded chitosan (CS)/polycaprolactone (PCL) nanofibrous films for fruit preservation and packaging. XRD results indicated that the THY/HPβCD inclusion complexes were successfully incorporated into the CS/PCL nanofibers . The nanofibrous films had an increase of average diameters of nanofibers from 243.84 nm to 560.55 nm, an enhancement of water vapor permeability, a decrease of the crystallinity , and a hydrophilic surface after the incorporation. FTIR and thermal analysis showed that the thermal stability was also improved due to the formation of hydrogen bonds between THY/HPβCD inclusion complexes and CS/PCL nanofibers. The developed films obtained a long-term continuous release of THY during 240 h, and had a good antifungal activity in vitro and in vivo . The above results indicated the promising prospects of SBS in developing antifungal nanofibrous films for postharvest fruit.

Biomineralized tetramethylpyrazine-loaded PCL/gelatin nanofibrous membrane promotes vascularization and bone regeneration of rat cranium defects

Wu Xiaoyu,Ni Su,Dai Ting,Li Jingyan,Shao Fang,Liu Chun,Wang Jiafeng,Fan Shijie,Tan Yadong,Zhang Linxiang,Jiang Qiting,Zhao Hongbin

Conventional electrospinning produces nanofibers with smooth surfaces that limit biomineralization ability. To overcome this disadvantage, we fabricated a tetramethylpyrazine (TMP)-loaded matrix-mimicking biomineralization in PCL/Gelatin composite electrospun membranes with bubble-shaped nanofibrous structures. PCL/Gelatin membranes (PG), PCL/Gelatin membranes containing biomineralized hydroxyapatite (HA) (PGH), and PCL/Gelatin membranes containing biomineralized HA and loaded TMP (PGHT) were tested. In vitro results indicated that the bubble-shaped nanofibrous surface increased the surface roughness of the nanofibers and promoted mineralization. Furthermore, sustained-release TMP had an excellent drug release efficiency. Initially released vigorously, it reached stabilization at day 7, and the slow-release rate stabilized at 61.0 ± 1.8% at 28 days. All membranes revealed an intact cytoskeleton, cell viability, and superior adhesion and proliferation when stained with Ghost Pen Cyclic Peptide, CCK-8, cell adhesion, and EdU. In PGHT membranes, the osteogenic and vascularized gene expression of BMSCs and human vascular endothelial cells was significantly upregulated compared with that in other groups, indicating the PGHT membranes exhibited an effective vascularization role. Subsequently, the membranes were implanted in a rat cranium defect model for 4 and 8 weeks. Micro-CT and histological analysis results showed that the PGHT membranes had better bone regenerative patterns. Additionally, the levels of CD31 and VEGF significantly increased in the PGHT membrane compared with those in other membranes. Thus, PGHT membranes could accelerate the repair of cranium defects in vivo via HA and TMP synergistic effects. Graphical Abstract

Confined crystallization and degradation of six-arm star PCL with core of cyclotriphosphazene in epoxy thermosets

Pengli Zhang,Yanfang Zhao,Rentong Yu,Jianhe Liao

Six-arm star polycaprolactone with core of cyclotriphosphazene ( s -PCL) was synthesized via ring-opening polymerization and characterized by NMR and GPC . Epoxy thermosets incorporating 10–40  wt % of this copolymer were cured with 4,4′-methylenebis(2-chloroaniline) (MOCA) and 4,4′-diaminodiphenyl sulfone (DDS), respectively. In these thermosets, intermolecular specific interactions had a significant impact on their morphologies. Specifically, no discernable macroscopic phase separation was found in FESEM images of MOCA-cured epoxy resins . However, for the DDS-cured system, s -PCL was partially miscible with the epoxy thermosets, as evidenced with FTIR and DMA. This is may be owning to enriched concentration of hydroxyl groups in the s -PCL favored the miscibility between PCL subchains of carbonyl and the epoxy matrix. Dispersed phase, further confirmed by XRD to be amorphous , with a diameter of 0.34–0.44 μm could be observed ( s -PCL’ content ≤ 20  wt %) in this system. Nevertheless, crystallization of PCL could not be suppressed completely ( s -PCL’ content > 30  wt %). Besides, epoxy thermosets containing crystalline PCL were found to be more resistant to thermal degradation but sensitive to alkaline degradation (10% NaOH aqueous solution) according to TGA and FESEM results. This work presented here is a meaningful report on the presence of alkaline-labile crosslinking points through the whole networks.

Preparation of Poloxamer188-b-PCL and Study on in vitro Radioprotection Activity of Curcumin-Loaded Nanoparticles

Lin Xiaona,Shi Yongli,Yu ShaSha,Li Siyi,Li Wenhui,Li Meishuang,Chen Shengxi,Wang Yuanbo,Cong Mei

A novel polymer of poloxamer188-b-PCL was synthesized via a ring-opening polymerization. Fourier transform infrared spectroscopy (FTIR), Raman, and 1H nuclear magnetic resonance (1H NMR) spectra were used to study the structures of obtained poloxamer188-b-PCL. The thermo-stability of poloxamer188 -b-PCL was carried out with a thermal gravimetric analyzer (TGA), and cytotoxicity was obtained using the CCK8 method. Cargo-free and curcumin (CUR)-loaded poloxamer188-b-PCL NPs were fabricated via the solvent evaporation method. The morphology, particle size distribution, and stability of cargo-free NPs were studied with a scanning electron microscope (SEM) and laser particle analyzer. The in vitro radioprotection activity of CUR-loaded NPs was performed. FTIR, Raman, and 1H NMR spectra confirmed that poloxamer188-b-PCL was obtained. TGA curves suggested poloxamer188-b-PCL had better thermo-stability than original poloxamer188. Cell tests suggested that the cargo-free NPs had no cytotoxicity. SEM image showed that the cargo-free NPs were spherical with a diameter of 100 nm. Free radical scavenging experiments proved that CUR-loaded NPs had better antioxidant activity than CUR solutions. CUR-loaded NPs could be detected in all tissues, including liver, kidneys and lung. In summary, this work demonstrated a feasibility of developing an injective formulation of CUR and provided a protection agent in caner radiotherapy.

Tuning pore features of mineralized collagen/PCL scaffolds for cranial bone regeneration in a rat model

Shuo Wang,Yongdong Yang,Gerry L. Koons,Antonios G. Mikos,Zhiye Qiu,Tianxi Song,Fuzhai Cui,Xiumei Wang

Porosity is indispensable for a bone tissue-engineered scaffold for facilitating endogenous cell migration and nascent bone ingrowth. In large-sized cranial bone defect repair, porous scaffolds meet great challenges to match cranial bone regeneration and provide sufficient protection with structural integrity. Therefore, the pore features of the scaffolds for cranial bone regeneration should differ from those typical porous scaffolds used in tubular bone repair and be finely tuned. In this study, a series of porous mineralized collagen/PCL scaffolds with different pore features were fabricated via freeze-drying and applied in a Sprague Dawley rat cranial bone calvarial defect model. The pore size for four groups increased from 10–45 μm to 40–130 μm. As scaffold porosity increased, the compressive strength decreased from 2.09 ± 0.12 MPa to 0.51 ± 0.04 MPa. The micro-computed tomography three-dimensional reconstruction images showed that as pore size and porosity increased, the amount of new bone formation had a maximum in group 3 (pore size: 20–100 μm, compressive strength: 1.06 ± 0.03 MPa). In addition, the histological and histomorphometric analyses showed a consistent tendency which confirmed the Micro-CT results. Meanwhile, histological findings including bony bridging, tissue response at the bone-implant interface and fibrous capsule thickness indicated that the dura mater pathway played the most important role in the regenerative process of this calvarial defect model.

One-step synthesis of PCL/Mg Janus micromotor for precious metal ion sensing, removal and recycling

Zhang Dongmei,Wang Dan,Li Jieai,Xu Xiaoyi,Zhang Hui,Duan Ruomeng,Song Bo,Zhang Dafeng,Dong Bin

The field of the micromotor has undergone continuous progresses, especially in the environmental remediation application. However, to the best of our knowledge, there are few micromotors which can sense, remove and recycle metal ions simultaneously. In this paper, we develop a Janus micromotor consisting of polycaprolactone (PCL) and magnesium (Mg) microparticle synthesized by one-step method. Due to the displacement reaction between Mg and the precious metal ions, the resulting micromotor can be self-propelled in hydrogen peroxide (H 2 O 2 ) solution. Since the motion velocity is highly dependent on both ion species and their concentrations, the micromotor can function as a motion-based metal ion sensor with good selectivity and sensitivity. In addition, since Mg alone is capable of propelling the whole structure in the presence of chloride ion (Cl − ), the water-driven PCL/Mg micromotor exhibits higher efficiency when utilized in noble metal removal and recycling as compared to that of the stationary one. We thus believe the one-step fabrication, precious metal ion sensing, removal and recycling capabilities make the current micromotor potentially attractive for polluted water monitoring and treatment.

Heparinized PCL/keratin mats for vascular tissue engineering scaffold with potential of catalytic nitric oxide generation

Xiuzhen Wan,Yanfang Wang,Xingxing Jin,Pengfei Li,Jiang Yuan,Jian Shen

Docetaxel-loaded PEO–PPO–PCL/TPGS mixed micelles for overcoming multidrug resistance and enhancing antitumor efficacy

Chunhuan Shi,Zhiqing Zhang,Fang Wang,Xiaoqing Ji,Zhongxi Zhao,Yuxia Luan

There are two major hurdles for the current anti-cancer drug delivery systems. One is the emergence of multidrug resistance (MDR) and the other is the conflict between long-circulation and cellular uptake. In the present study, the anticancer drug docetaxel (DTX) was successfully loaded into three series of micelles via self-assembly using a mixture of PEO–PPO–PCL and D-α-tocopheryl poly(ethylene glycol) 1000 succinate (TPGS), for the purpose of prolonging the blood circulation time as well as overcoming MDR of DTX. Three series of copolymers with different PCL molecular weights, PEO68–PPO34–PCL9, PEO68–PPO34–PCL18 and PEO68–PPO34–PCL36, were synthesized. The prepared spherical mixed micelles (MM) were found to possess nanoscale size (25–135 nm). The PEO–PPO–PCL/TPGS mixed micelles had a low critical micelle concentration (∼10−6 g mL−1) and a low hemolysis rate (<5%), which has proved that they are safe for use in vivo. Moreover, they had obvious sustained release behavior in vitro and a longer circulation time than free DTX in vivo. The P-gp inhibition assay, cellular uptake and MTT assay in cancer cells exhibited that DTX-loaded MM could overcome MDR, show higher cellular uptake and higher antitumor efficacy than free DTX. The IC50 values demonstrated that the three series of DTX-loaded MM were 69, 82 and 100 fold effective than free DTX after 72 h treatment with MCF-7 cells, respectively. Therefore, these results demonstrated that the prepared DTX-loaded MM provide desirable application in cancer chemotherapy.

Targeted delivery of low-dose dexamethasone using PCL–PEG micelles for effective treatment of rheumatoid arthritis

Qin Wang,Jiayu Jiang,Wenfei Chen,Hao Jiang,Zhirong Zhang,Xun Sun

Glucocorticoid (GC) is the cornerstone therapy of rheumatoid arthritis , but high doses are associated with serious adverse effects. In an effort to improve the efficacy of low-dose GC therapy, we developed a micelle system for targeted delivery to inflamed joints and validated the approach in a rat model of arthritis. Micelles loaded with dexamethasone (Dex) self-assembled from the amphipathic poly (ethylene glycol)-block–poly (ε­caprolactone) (PCL–PEG) polymer via film dispersion, and they were injected intravenously at a dose of only 0.8   mg/kg into rats with adjuvant-induced arthritis. The micelles persisted for a relatively long time in the circulation, and they accumulated preferentially in inflamed joints. Micelle-delivered Dex potently reduced joint swelling, bone erosion, and inflammatory cytokine expression in both joint tissue and serum. PCL–PEG micelles caused only moderate adverse effects on body weight, lymphocyte count and blood glucose concentration, and they weakly activated the host complement system. These results suggest that encapsulating Dex in PCL–PEG micelles may allow for safe and effective low-dose GC therapy targeting inflammatory disorders.

Design of poly(mPEGMA-co-MAA) hydrogel-based mPEG-b-PCL nanoparticles for oral meloxicam delivery

Yongli Shi,Zhaomin Liu,Yaxing Yang,Xiaojie Xu,Yan Li,Tong Li

To enhance the therapeutic effects of meloxicam (MLX), we developed an oral MLX-loaded poly(ethylene glycol)-b-poly(ε-caprolactone) nanoparticles@hydrogel (MLX-NPs@hydrogel) preparation. The MLX-NPs were fabricated via a solvent evaporation method, and their morphologies were observed by a JEM-1011 transmission electron microscope (TEM). The poly(mPEGMA- co -MAA) hydrogels were synthesized, and studies on their pH sensibilities were carried out in pH   1.2, 6.8, and 7.4 buffers. The final MLX-NPs@hydrogel preparation was obtained by immersing the hydrogels in the MLX-NPs suspensions (pH   7.4) for 48   h. The thermodynamic properties and cytotoxicity of the MLX-NPs@hydrogel preparation were also studied. TEM images illustrated that mPEG-b-PCL NPs had a uniform size distribution. The poly(mPEGMA- co -MAA) hydrogels showed an excellent pH-sensibility. Thermal gravity analysis (TGA) data suggested that the protection of hydrogels improved the stability of mPEG-b-PCL NPs. The release studies revealed that MLX-NPs@hydrogel could deliver the MLX-NPs into alkalescent environment ( e.g. intestinal tract). Then, the medicated NPs released MLX at a sustained release profile. Such preparation could overcome the drawbacks of oral MLX, and enhance its therapeutic effects. Therefore, the NPs@hydrogel was a promising sustained-controlled release matrix.

Dynamic culturing of large cell-loaded PCL/gelatin methacryloyl scaffolds for bone critical size defect repair

Guangxin Shen,Botao Gao,Jiayi Guo,Weikang Xu,Guangfu Chen,Shuai Huang,Zhiwen Zeng,Xiaodong Zhao

Due to the limited ability to self-repair, the regeneration of bone critical-sized defects (CSD) is a significant challenge. Bone tissue engineering scaffolds are considered promising candidates for CSD repair, but low cell infiltration efficiency and a lack of nutrients greatly restrict bone regeneration abilities. Herein, we developed a dynamic culturing of large biomimetic bone scaffolds, PCL/GelMA@cells that combining 3D printed polycaprolactone (PCL) multi-channel cylinder with gelatin methacryloyl (GelMA) encapsulated with bone marrow mesenchymal stem cells (BMSCs) and rat aortic endothelial cells (RAECs). A cell dynamic culture system was fabricated to simulate the dynamic microenvironment. Compared to static culturing, dynamic culturing proved to enhance the nutrient exchange within the large scaffold to promote the cells infiltration, growth, proliferation and induce osteogenic and angiogenic differentiation. Furthermore, a rat cranial CSD (D = 10 mm) repair model verified the accelerated vascular ingrowth and new bone formation with the implantation of dynamic culturing of PCL/GelMA@cells scaffold (∼10 times higher than Blank group), indicating the great potential of dynamical culturing of scaffolds for bone repair. In summary, the results highlight the significant advantages of the dynamical culturing of cell-loaded scaffolds for bone regeneration, offering a promising strategy for addressing critical size bone defects.