查找使用阿拉丁产品的科研文献

Poly-Lactide-Co-Glycolide-Polyethylene Glycol-Ginsenoside Rg3-Ag Exerts a Radio-Sensitization Effect in Non-Small Cell Lung Cancer

Ma Jun,Yu Da-Hai,Zhao Di,Huang Teng,Dong Min,Wang Ting,Yin Hai-Tao

Radiotherapy is an effective anti-cancer therapy for patients with non-small cell lung cancer (NSCLC), however, the prognosis is unsatisfactory owing to radio-resistance and toxicity. It is crucial to improve radiotherapy efficacy. Ag nanoparticles (NPs) and ginsenoside Rg3 (Rg3) exerted antitumor and radio-sensitization effects. Therefore, we investigated whether poly-lactide-co-glycolide-polyethylene glycol (PLGA-PEG)-Rg3-Ag will function as a noninvasive, tracing, radiotherapy sensitizer. The morphology of NPs was visualized with transmission electron microscopy (TEM). The drug loading content, encapsulation efficiency, and cumulative drug release of Rg3 was determined by HPLC. Cellular uptake of NPs in A549 and SPCA-1 was measured by immunostaining. The radio-sensitization effect of PLGA-PEG-Rg3-Ag in vitro was determined in A549 by detecting proliferation, colony formation, and apoptosis with CCK-8, clonogenic survival assay, and flow cytometry, while in vivo was determined in nude mice by testing the body weight and tumor volume. PLGA-PEG-Rg3-Ag exerted radio-sensitization effect by reducing cell proliferation and colony formation while enhancing cell apoptosis in A549; reduced tumor volume in nude mice. PLGA-PEG-Rg3-Ag exhibits radio-sensitization effects in NSCLC.

Composites from biodegradable and biocompatible methylcellulose, poly(d,l-lactide-co-glycolide) and poly(1,4-butylene succinate) with enhanced properties

Airong Xu,Fen Wang,Luwei Zhang,Xingmin Xu,Zhihong Xiao,Rukuan Liu

Polymer materials based on fossil resources have brought great convenience to various industries. However, environmental pollution is becoming increasingly conspicuous due to their difficult degradation in nature. Therefore, biodegradable composites are highly desired. In the present work, a simple and feasible preparation approach was presented to fabricate biodegradable and biocompatible composite films including methylcellulose/poly( d , l -lactide-co-glycolide) (MC/PLGA) and methylcellulose/poly(1,4-butylene succinate) (MC/PBS). The effects of MC/PLGA and MC/PBS mass ratios on the morphology, crystalline state, mechanical properties and thermal stability of the composite films were systematically investigated. At the same time, the influence of thermal compression treatment on mechanical properties (tensile strength and elongation) and the cyclic utilization of the composite films were also estimated. The composite films displayed enough good mechanical properties, re-usability and thermal stability.

Poly(lactide-co-glycolide) grafted hyaluronic acid-based electrospun fibrous hemostatic fragments as a sustainable anti-infection and immunoregulation material

Wen Liu,Guanghui Xi,Xiao Yang,Xiao Hao,Mingshan Wang,Yakai Feng,Hao Chen,Changcan Shi

Poly(lactide-co-glycolide) (PLGA) copolymers are promising synthetic materials in the biomedical field. However, in wound management, their hydrophobic properties limit their further application because of their poor adhesion to the surface of moist wounds. Furthermore, the lack of hemostatic materials with sustainable anti-infection and immunoregulation functions remains a highly significant clinical problem, as commercially available hemostatic products, such as Arista™, Celox™ and QuikClot™, do not have sufficient infection prevention and immunoregulation properties. Herein, we employ electrospinning, ammonia dissociation and surface grafting techniques to develop a series of PLGA-based hemostatic materials, including a PLGA electrospun fibrous membrane, PLGA-NH2 fibrous particles and PLGA-hyaluronic acid fibrous fragments (PLGA-HA FFs). Notably, we load azithromycin on the PLGA-HA FFs to endow them with anti-infection and immunoregulation properties. The hemostatic mechanism analysis demonstrates that the PLGA-HA FFs show superior hemostasis performance compared to traditional gauzes. The results show that the PLGA-HA FFs can act as a versatile platform with high encapsulation of azithromycin (83.03% ± 2.81%) and rapid hemostasis (28 ± 2 s) as well as prominent cytocompatibility towards L929 cells, RAW 264.7 cells and red blood cells. We believe that the current research proposes a possible strategy to synthesize materials that achieve not only safe and effective hemostasis, but also have anti-infection and immunoregulation properties for the development of further hemostatic products.

Idarubicin-loaded methoxy poly(ethylene glycol)-b-poly(l-lactide-co-glycolide) nanoparticles for enhancing cellular uptake and promoting antileukemia activity

Bin Liang,Na Li,Shuofei Zhang,Aihua Qi,Jianhua Feng,Weiwei Jing,Changcan Shi,Zhaipu Ma,Shenmeng Gao

Self-assembled micelles prepared from poly(D,L-lactide-co-glycolide)-poly(ethylene glycol) block copolymers for sustained release of valsartan

Qingzhen Zhu,Baogang Zhang,Yuandou Wang,Xinghua Liu,Weiwei Li,Feng Su,Suming Li

Poly( D , L -lactide-co-glycolide)-poly(ethylene glycol) (PLGA-PEG) diblock copolymers with different compositions were synthesized by ring-opening polymerization of D , L -lactide and glycolide, using monomethoxy PEG as macro-initiator. The resulting copolymers were characterized by nuclear magnetic resonance, gel permeation chromatography, and critical micelle concentration analyses. Self-assembly of the copolymers yielded aggregates of different architectures, including spherical micelles and a mixture of spherical and worm-like micelles with Y-junctions. The self-assembled architecture depends on both the hydrophilic/hydrophobic balance and the molar mass of copolymers. Valsartan, a widely used drug in the treatment of hypertension, was loaded in micelles using a co-solvent evaporation method. High drug-loading content was obtained for worm-like micelles. in vitro drug release was performed at 37°C in pH 7.4 phosphate-buffered saline. An initial burst release is detected in all cases, followed by slower release up to 9 days. The overall release rate is strongly dependent on the degradation of micelles. Copolymers with short PLGA blocks exhibit faster drug release due to faster degradation of micelles, and worm-like micelles present slower drug release as compared to spherical ones. Therefore, PLGA-PEG copolymer micelles with high drug-loading capacity, different architectures, and variable drug release rates could be most attractive for sustained delivery of valsartan.

Preparation and Characterization of Poly(L-lactide-co-glycolide-co-ε-caprolactone)/Nano-biaoactive Glass-Nano-β-tricalcium Phosphate Composite Scaffolds

Hailin Xie,Zhihua Zhou,Wenjuan Liu,Yanmin Zhao,Tianlong Huang,Ping Chen,Ziwei Zhou,Dan Wang,Jianglong Duan,Jianjun Fang

Polymeric/ceramic composite scaffolds that are biocompatible and biodegradable are widely used for tissue engineering applications. In this work a series of poly(L-lactide-co-glycolide-co-ε-caprolactone)/nano-biaoactive glass-nano-β-tricalcium phosphate composite scaffolds were successfully fabricated and the influences of the inorganic content and freezing temperature on the physical properties were studied. The composite scaffolds with various inorganic contents showed an interconnected pore structure with irregular shapes. The composite scaffolds had a porosity that was reduced with increasing inorganic content and decreasing freezing temperature. The incorporation of inorganic fillers and decreasing freezing temperature improved the mechanical properties of the hybrid scaffolds. By appropriate control of these two factors (10.0 wt% content of NBAG and β-TCP with freezing at −30 °C) a suitable composite scaffold was prepared as a potential bone tissue engineering implant.

Nanoparticles of Chitosan/Poly(D,L-Lactide-Co-Glycolide) Enhanced the Immune Responses of Haemonchus contortus HCA59 Antigen in Model Mice

Qiangqiang Wang,Xiaoke Sun,Xin Huang,Jianmei Huang,Muhammad Waqqas Hasan,RuoFeng Yan,Lixin Xu,Xiaokai Song,Xiangrui Li

Background Hepatocellular carcinoma-associated antigen 59 (HCA59) from excretory/secretory products of Haemonchus contortus is known to have the ability to modulate the functions of host cells. However, its immunogenicities using different nanoparticles adjuvants remain poorly understood. Purpose The study aimed to select an efficient nanoparticle antigen delivery system, which could enhance the immune responses of Haemonchus contortus HCA59 in mice. Methods Here, the immune responses induced by the recombinant protein of HCA59 (rHCA59) with poly-D,L-lactide-co-glycolide (PLGA) nanoparticles, Chitosan nanoparticles, mixture of PLGA and Chitosan nanoparticles (rHCA59-Chitosan-PLGA), and Freund’s complete adjuvant were observed, respectively, in mice. Cytokine and antibody levels induced by different groups were detected by ELISA assay. The effects of lymphocyte proliferations on different groups were examined using CCK-8 kit. Phenotypes of T cells and dendritic cells were analyzed by flow cytometry. Results On day 14 post vaccination, levels of IgM, IgG1, IgG2a, IFN-γ, IL-4, and IL-17 were significantly increased in the groups immunized with rHCA59 encapsulated with nanoparticles. After mice were vaccinated with rHCA59 loaded with Chitosan/PLGA nanoparticles, lymphocytes proliferated significantly. Additionally, the percentages of CD4 + T cells (CD3 + CD4 + ), CD8 + T cells (CD3 + CD8 + ), and dendritic cells (CD11c + CD83 + , CD11c + CD86 + ) were obviously up-regulated in the mice immunized with nanoparticles, especially in the rHCA59-Chitosan-PLGA antigen delivery system group. Conclusion The findings of this research demonstrated that rHCA59-Chitosan-PLGA antigen delivery system could induce higher immune responses in mice model and indicated that rHCA59 might be a good candidate molecule to develop nanovaccines against Haemonchus contortus in future study.

Tracing Carbon Nanotubes (CNTs) in Rat Peripheral Nerve Regenerated with Conductive Conduits Composed of Poly(lactide-co-glycolide) and Fluorescent CNTs

Zirong Huang,Yizhan Ma,Wei Jing,Yanling Zhang,Xiaolong Jia,Qing Cai,Qiang Ao,Xiaoping Yang

Nerve regeneration can be promoted using nerve guide conduits (NGCs). Carbon nanotubes (CNTs) are often used to prepare conductive NGCs, however, the major concern for their applications is the final location of the implanted CNTs in vivo. Herein, photoluminescent multiwalled CNTs (MWCNTs) were prepared and electrospun with poly(lactide-co-glycolide) (PLGA), followed by shaping into multichannel NGCs for repairing of injured rat sciatic nerve, thereby the distribution of CNTs in vivo could be detected via bioimaging. Photoluminescent MWCNTs (MWCNT-FITC) were prepared by functionalization with poly(glycidyl methacrylate) (PGMA) and fluorescein-isothiocyanate-isomer I (FITC) subsequently. The conductivity of the PLGA/MWCNT-FITC fibers was approx. 10–4 S/cm at 3 wt % MWCNTs. Compared with PLGA fibers, Schwann cells on PLGA/MWCNT-FITC fibers matured at a faster rate, accordingly, nerve regeneration was promoted by the PLGA/MWCNT-FITC NGC. With a confocal laser scanning microscope and small-animal imaging system, the location of MWCNTs was detected. Alongside the degradation of PLGA, MWCNTs intended to aggregate and were entrapped in the regenerated nerve tissue without migrating into surrounding tissues and other organs (liver, kidneys, and spleen). This study provides a useful characterization method for MWCNTs and the guidance for in vivo applications of MWCNTs in tissue engineering.

Tumor Tropic Delivery of Hyaluronic Acid-Poly (D,L-lactide-co-glycolide) Polymeric Micelles Using Mesenchymal Stem Cells for Glioma Therapy

Xiao-Ling Wang,Wen-Zheng Zhao,Jia-Ze Fan,Le-Chen Jia,Ya-Nan Lu,Ling-Hui Zeng,Yuan-Yuan Lv,Xiao-Yi Sun

Tumor penetration and the accumulation of nanomedicines are crucial challenges in solid tumor therapy. By taking advantage of the MSC tumor-tropic property, we developed a mesenchymal stem cell (MSC)-based drug delivery system in which paclitaxel (PTX)-encapsulating hyaluronic acid-poly (D,L-lactide-co-glycolide) polymeric micelles (PTX/HA-PLGA micelles) were loaded for glioma therapy. The results indicated that CD44 overexpressed on the surface of both MSCs and tumor cells not only improved PTX/HA-PLGA micelle loading in MSCs, but also promoted the drug transfer between MSCs and adjacent cancer cells. It was hypothesized that CD44-mediated transcytosis played a crucial role and allowed deep glioma penetration depending on sequential intra–intercellular delivery via endocytosis–exocytosis. MSC-micelles were able to infiltrate from normal brain parenchyma towards contralateral tumors and led to the eradication of glioma. The survival of orthotopic glioma-bearing rats was significantly extended. In conclusion, the MSC-based delivery of HA-PLGA micelles is a potential strategy for tumor-targeting drug delivery.Keywords:mesenchymal stem cells;hyaluronic acid;poly (lactide-co-glycolide);orthotopic glioma;tumor penetration

Synthesis and characterization of innovative poly(lactide-co-glycolide)-(poly-L-ornithine/fucoidan) core–shell nanocarriers by layer-by-layer self-assembly

Jingqian Fan,Yuangang Liu,Shibin Wang,Yulu Liu,Siming Li,Ruimin Long,Ran Zhang,Ranjith Kumar Kankala

Layer-by-Layer (LbL) self-assembly of nanocarriers has garnered the interest of researchers for a wide variety of biomedical applications. In this study, we demonstrated the preparation of poly(lactide-co-glycolide) (PLGA)-(poly-L-ornithine (PLO)/fucoidan)4 core–shell nanoparticles (LbL NPs) by a LbL-based self-assembly process, which possessed a mean size of 170 nm. In LbL NPs, a drug carrying PLGA nano-core is coated with alternating PLO and sulfated polysaccharide fucoidan composite films as a shell on the surface. The anti-tumor drug doxorubicin (DOX) loaded into the PLGA core, resulted in better encapsulation efficiency and its in vitro release from LbL NPs demonstrates that this core–shell strategy takes an advantage of its ability to hold the drug cargo and exhibit controlled release. Further, in vitro cell uptake studies by confocal laser scanning microscopy (CLSM) examination in breast tumor cells (MCF-7 cell line) have confirmed that the nanocarriers are successfully internalized and outlined their presence in the cytoplasm after 4 h of incubation. These intracellularly delivered DOX-loaded LbL NPs exhibited significant anti-tumor activity against breast tumor cells. This innovative chemotherapeutic design taking above advantages of successful internalization along with controlled release property signifies as a promising interventional therapeutic delivery system.

Construction of poly (vinyl alcohol)/poly (lactide-glycolide acid)/vancomycin nanoparticles on titanium for enhancing the surface self-antibacterial activity and cytocompatibility

Zehui Liu,Yizhou Zhu,Xiangmei Liu,K.W.K. Yeung,Shuilin Wu

Comparing with traditional drug dosage form, controlled release systems offer more effective and favorable route to deliver drugs in optimum dose to specific sites with long term release duration. In this work, an effective drug delivery system composed of poly (vinyl alcohol) (PVA)/poly (lactide-glycolide acid) (PLGA) nanoparticles (NPs) with encapsulated vancomycin (Van), is constructed on the surface of biomedical titanium. The PVA/PLGA/Van NPs synthesized via double emulsion route are grafted onto the surface of titanium plates modified by alkaline-heat treatment and subsequent aminopropyltriethoxysilane (APTES) deposition. In vitro tests disclose that NPs can release a small amount of drugs continuously due to the slow swelling or hydrolysis of polymer chain segments as the immersion time increases. As the pH value reduces, the ester bonds rupture with releasing more drugs, which is why this drug delivery system exhibits the highest antibacterial efficiency at the lowest pH value of 4.5 in this work. Cell culture results reveal that this smart surface system on titanium facilitates the cell attachment and proliferation on implants. Hence, this pH controlled drug delivery system can be successfully applied as a bio-platform for improving both the osteoblasts adhesion and antibacterial activity of metallic implants.

Intracellular Activity of Poly (DL-Lactide-co-Glycolide) Nanoparticles Encapsulated with Prothionamide, Pyrazinamide, Levofloxacin, Linezolid, or Ethambutol on Multidrug-Resistant Mycobacterium tuberculosis

Jiang Huixian,Li Xiang,Xing Zhenjian,Niu Qun,Xu Jiangping

Background: Multidrug-resistant Mycobacterium tuberculosis (MDR-TB) is a major cause of death amongst tuberculosis patients. Nanomedicine avoids some limitations of conventional drug treatment and increases therapeutic efficacy against bacterial infections. However, the effect of anti-TB drug nanoparticle (NP) compounds in anti-TB regimens against MDR-TB remains unclear. Objective: The objective of this article is to prepare levofloxacin, linezolid, ethambutol, prothionamide, and pyrazinamide encapsulated NPs and to evaluate their therapeutic efficacy against MDR-TB in macrophages. Methods: Drug-loaded PLGA NPs were prepared by the multiple emulsion method. The colocalization, intracellular release, and anti-TB activity of these NPs were investigated on cultured macrophages. The immune phenotype of the macrophages, including their mitochondrial membrane potential, reactive oxygen species (ROS), and nitric oxide (NO) production, was evaluated following treatment with NPs or free drug compounds. Results: All drug-loaded PLGA NPs were spherical in shape, 150 to 210 nm in size, and showed 14.22% to 43.51% encapsulation efficiencies and long-duration release. Drug-loaded PLGA NPs were mainly distributed in the cytoplasm of macrophages, showed high cellular compatibility, and maintained their concentration for at least 13 days. Compared with the free drug compounds, the number of colonies after exposure to PLGA NP compounds was significantly less. The enhanced antibacterial activity of the NP compounds may be due to the enhanced levels of ROS and NO and the increased early apoptosis stress within M. tuberculosis-infected macrophages additionally. Conclusion: The application of PLGA NP compounds not only enhances drug efficacy but also induces innate bactericidal events in macrophages, confirming this as a promising approach for MDR-TB therapy.