Scientific Reports
·
2020
·Vol. 10
·期 1
·1-12
·
IF 3.998
Wu Yifan,Li Lingtong,Chen Shaopeng,Qin Jun,Chen Xiaolang,Zhou Dengfeng,Wu Hong
Poly( D -lactic acid) (PDLA) with different polyethylene glycol (PEG) segment synthesized PDLA-PEG-PDLA triblock copolymer through the ring-opening reaction of D -LA and PEG will be used as a toughening modifier. The microstructure, crystal structures and crystallization behaviors of this triblock copolymer were investigated by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, X-ray diffraction (XRD), differential scanning calorimetry (DSC) and polarized optical microscopy (POM). The triblock copolymer is synthesized from the appearance of CH 2 stretching vibration peak at 2910 cm −1 and C-O stretching vibration peak at 1200 cm −1 from PEG in FTIR spectra. Moreover, the chemical shift that is about 3.6 ppm in 1 H NMR and 68.8ppm in 13 C NMR proves this matter. The results of XRD and DSC reveal that PDLA and PEG are crystallized separately, and are not fully compatible, and microphase separation has occurred in this triblock copolymer. PEG can induce the triblock copolymer to accelerate the rate of crystallization, allowing it to crystallize more completely in the same amount of time. When the molecular weight of PEG is 6000 or the ratio of D -LA/PEG is 1/1, the crystallizability of PDLA-PEG-PDLA triblock copolymer is the best.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 17
·
IF 1.86
Yanmei Guo,Jun Shao,Haoqing Hou
Linear poly( d -lactide) (PDLA) with various molecular weights is synthesized and incorporated into commercial poly( l -lactide) (PLLA) with different optical purities. And then, the crystallization, mechanical and thermal properties of the PLLA and PLLA/PDLA cast films are investigated. In the PLLA and PDLA/PLLA specimens with lower optical purity, few homochiral crystallites (HC) form in all the specimens and only a small amount of PLA stereocomplex crystallites (SC) are observed in the blends. The elongation at break of all the specimens is extraordinary high, >300%. Dynamic mechanical analyses indicate that the destruction temperature increases at first, and then depresses as enlarging the molecular weight of PDLA in these blends. For the PLLA and PLLA/PDLA with higher optical purity, more content of HC develops in neat PLLA, and both SC and HC produce in the PLLA/PDLA specimens. However, the strains of neat specimens and binary blends are much lower than that of specimens with lower optical purity. The specimens with higher optical purity exhibit higher destruction temperatures and lower loss factors. The high content of crystals (SC and HC) would act as the physical cross-linking points and provide a key factor to impede the deformation of neat PLLA and binary blends during stretching, which should result in the fragile behavior of the PLLA and PLLA/PDLA blends with higher optical purity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44730.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF BIOACTIVE AND COMPATIBLE POLYMERS
·
2013
·
IF 2.207
Feng Xu,Ting-Ting Yan,Yan-Ling Luo
Novel amphiphilic block copolymers consisting of hydrophobic poly(D,L-lactide) segments and hydrophilic poly(N-isopropylacrylamide-co-N, N-dimethylacrylamide) blocks were designed and synthesized through a simple free radical copolymerization route based on a bifunctional initiator, followed by the ring-opening polymerization of D,L-lactide. The copolymers self-assembled into thermosensitive spherical-nanosized core–shell micelles in aqueous solution in the presence or the absence of the model drug prednisone. The chemical and physical characterizations of drug-loaded and unloaded micelles revealed a lower critical solution temperature of 40°C–47°C, and a critical micelle concentration less than 7.20 mg L−1, a transmission electron microscope mean particle size from 50 to 75 nm, and a narrow dynamic light scattering diameter below 180 nm. The prepared blank and drug-loaded micellar nanoparticles were thermodynamically stabile and employed in targeted drug delivery by responding to the higher temperature of the local microenvironment. Based on prednisone release kinetic studies, structural changes of the self-assembled micelles as well as temperature- or environment-induced diffusion controlled drug release and improved bioavailability. The copolymer micelles exhibited good biocompatibility as established by the MTT cytotoxicity assay. Therefore, an effective target therapy against lesion tissues is feasible using these polymeric micelles.
研究领域:
材料科学
·
生物医学工程
·
药学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 8
·2419
·
IF 4.927
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
研究领域:
药学科学
·
癌症治疗
·
干细胞研究
·
纳米医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2022
·Vol. 41
·期 7
·1115-1122
·
IF 3.815
Zhong Chan-Na,Liu Ya-Dong,Tang Juan,Chen Wei-Shuo,Li Shuang-Cheng,Shao Jun,Hou Hao-Qing
Blending of poly(levorotatory-lactic acid) (PLLA) and poly(dextrorotatory-lactic acid) (PDLA) produces the stereocomplex crystallites (PLA SC), which present higher melting temperature and mechanical properties than that of neat PLLA or PDLA. However, in the PLLA/PDLA blends with higher molecular weights, the phase separation occurs and the SC exhibits weak memory after melting, which lead to a small amount of SC together with a large amount of homochiral crystallites (HC) develop during crystallization from the melt. In this study, a small content of graphite oxide was blended with PLLA and PDLA to form ternary blends, and it was exciting to find that the formation of SC was enhanced gradually with the content of graphite oxide. The SC exclusively developed when 2 wt% graphite oxide was incorporated into the PLLA/PDLA, and the crystallinity with ∼50% was received even during fast cooling from the melt (−50 °C/min). The acceleration formation of SC was speculated due to the interaction between PLA molecular chains and the hydroxyl groups on the surface of graphite oxide and the obstruction of proliferation of graphite oxide.
研究领域:
高分子科学
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材料工程
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纳米复合材料
·
结晶动力学
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 129
·期 2
·767-772
·
IF 1.289
Dagen Zhong,Zonghua Liu,Shasha Xie,Wei Zhang,Yuanming Zhang,Wei Xue
This work is to develop a novel dual drug delivery system that can simultaneously load and release 18β-glycyrrhetinic acid (GA, a hydrophobic drug) and bovine serum albumin (BSA, hydrophilic model drug) in a single formulation. The system consists of poly( D,L -lactic) (PDLLA) microspheres embedded in calcium alginate hydrogel beads. The GA-loaded microspheres were first prepared and then dispersed in the aqueous solution of sodium alginate and BSA. The resulting suspension was dropped into aqueous calcium chloride solution to obtain the dual drug delivery system. The morphology of the microspheres and beads, the drug content and loading efficiency, the interaction between GA and PDLLA, and the drug release behaviors were studied. Scanning electron microscope (SEM) revealed that the PDLLA microspheres were homogeneously distributed in the beads. Differential scanning calorimetry (DSC) measurement suggested certain interaction between GA and PDLLA, and the crystal structure of GA was influenced by the polymer. The dual release in vitro showed a rapid BSA release but a sustained GA release in all the systems. Furthermore, the release rate of BSA was accelerated by increasing PDLLA/alginate ratio, while the release rate of GA was decreased, and the release of both hydrophobic and hydrophilic drugs could be adjusted by changing the ratio of PDLLA/alginate. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 20122
研究领域:
药物递送
·
生物材料
·
制药工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Congshu Feng,Yun Chen,Jun Shao,Haoqing Hou
Blending of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) would produce polylactide stereocomplex crystallites (PLA SC). In the PLLA/PDLA specimens prepared by solution mixing or melt blending, the isomeric polymers were mixed in the molecular level. When the distance of these isomers increased, the crystallization behaviors of PLLA/PDLA were not clear yet. In this study, PLLA/PDLA blends were prepared by different electrospinning methods, i.e., spinning by mixed solution (DL-A), side-by-side mode (DL-B), and double spinnerets (DL-C). Results revealed that the distances between isomeric molecules increased in the order of DL-A, DL-B, and DL-C, and this distance influences the phase transition and subsequently crystallization behaviors. In the DL-A, the homochiral crystallites (HC) developed at first, and then SC formed in the specimen with lower content of PDLA. The formation of SC was observed at first, and less or no content of HC was developed with higher content of PDLA. For the DL-B group, the formation of HC was observed at ∼100 °C, and the SC were produced around 140 °C irrespective of composition. More content of SC was produced during or after melting of HC. When referring to the DL-C group, the HC developed at the first stage, and the SC were produced during or after melting of PLA HC. In addition, the SC that developed in the three groups have different nucleation efficiencies for the subsequent formation of HC. The nucleation efficiency increased in the order of DL-A < DL-B < DL-C, and these results hinted that not only the content but also the distribution of SC affects the formation of HC.
研究领域:
材料科学
·
高分子科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 1
·731-745
·
IF 3.553
Wang Jingguang,Gao Huichang,Hu Yang,Zhang Naiyue,Zhou Wuyi,Wang Chaoyang,Binks Bernard P.,Yang Zhuohong
Abstract Biocompatible and bioactive scaffolds with multiscale porosity, shape memory effect and drug delivery performance are highly promising in bone tissue engineering applications within the approach of minimally invasive surgical implantation. In this study, we report an effective method to fabricate multiscale porous bioactive (MPB) scaffolds with shape memory effect by freeze drying of 3D printed high internal phase Pickering emulsion (Pickering HIPE) templates stabilized by hydrophobically modified hydroxyapatite and silica nanoparticles. MPB scaffolds containing a shape memory polymer matrix of poly(D,L-lactide-co-trimethylene carbonate) display high porosity and fully interconnected filament networks with multiscale pore structures. The in vitro biomineralization study verifies that MPB scaffolds are bioactive with the apatite formation ability. The thermal property testing shows that the glass transition temperature of MPB scaffolds is easily tuned to fall between 45.9 and 49.1 °C by varying the HIPE composition. Moreover, MPB scaffolds exhibit observable shape memory properties with fast shape recovery. The antibacterial drug enrofloxacin can be efficiently loaded into MPB scaffolds and then released in a sustained manner displaying effective antimicrobial effect. Furthermore, cell culture assays confirm that MPB scaffolds could sustain the cell growth, proliferation and osteogenic differentiation, indicating the cytocompatibility and osteoinduction activity of MPB scaffolds. Therefore, combining freeze drying with 3D printing of Pickering HIPE templates paves the way towards MPB scaffolds with shape memory effect, which are promising as minimally invasive implantation scaffolds in bone tissue engineering applications. Graphic Abstract
研究领域:
生物医学工程
·
组织工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Biomedical Physics & Engineering Express
·
2022
·Vol. 8
·期 3
·035002
·
IF 0
Siqi Li,Xiaoling Yu,Yuan Li,Tian Zhang
For nerve tissue engineering (NTE), scaffolds with the ability to release drugs under control and support the rapid proliferation of cells are very important for the repair of nerve defects. This study aimed to fabricate a conductive drug-loaded fiber mat by electrospinning and assess its potential as a scaffold for Schwann cells proliferation. The conductive polypyrrole (PPy) was coated on an electrospun poly (D, L-lactide) (PLA) fibrous mat, which was simultaneously embedded with protein-loaded chitosan nanoparticles and ibuprofen as a model small molecule drug. The fibrous mat shows suitable conductivity, mechanical properties, and hydrophilicity for NTE. For drug release and degradation studies, the fibrous mat can achieve sustained release of bovine serum albumin (BSA) and ibuprofen, and the PPy coating can increase the surface wettability and conductivity while slowing down the degradation of the fibrous mat. The application of electrical stimulation (ES) to the fibrous mat can accelerate the release of ibuprofen, but there was no significant effect on the release rate of the protein. The fibrous mat showed no cytotoxicity in vitro, and Schwann cells (SCs) can adhere, grow, and proliferate well on mats. At the 120th hour of culture in vitro, the relative growth rate of SCs on the conductive drug-loaded fibrous mat reached 198.22 ± 2.34%, which was an increase of 37.93% compared to the SCs on the drug-loaded fibrous mat with ES. The density and elongation of SCs on the conductive drug-loaded fibrous mat were greater than those on the PLA fibrous mat, indicating that the conductive polypyrrole-coated electrospun chitosan nanoparticles/PLA fibrous mat has good potential for application in nerve regeneration.
研究领域:
材料科学
·
生物医学工程
·
组织工程
·
神经科学
✓ 已验证
DOI
CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Wenjun Liu,Ling Zhu,Yunfa Ma,Lihao Ai,Wei Wen,Changren Zhou,Binghong Luo
In order to better utilize and combine the advantages of poly( d , l -lactide) (PDLLA) matrix and natural polysaccharide chitin whiskers (CHWs), needle-like CHWs with chiral nematic liquid crystal characteristics and remarkable moduli were chosen to surface modify PDLLA film. By a vertical coating method, a stable and well-ordered CHWs coating was formed on the surface of the PDLLA film through a polydopamine (PDA) interlayer. The high stability of the well-ordered CHWs coating on the surface of the PDLLA film was confirmed by PBS soaking experiment in terms of the changes of weight and surface morphology of the film. The surface microstructure and composition of the resulting PDLLA-PDA-CHWs film were characterized by field emission scanning electron microscopy (FESEM), atomic force microscope (AFM) and X-ray photoelectron spectroscopy (XPS), and the thickness of the PDLLA, PDA and CHWs layers was determined using FESEM, too. Comparing with traditional PDLLA/CHWs film, prepared by solution blending with optimal content of 5 wt% CHWs, the hydrophilicity and mechanical properties of the PDLLA-PDA-CHWs film were significantly improved owing to the immobilization of a highly ordered CHWs coating. Furthermore, in vitro cell culture showed that the well-ordered CHWs coating had a more significant effect on promoting the adhesion, spreading, proliferation and osteogenic differentiation of MC3T3-E1 cells. All these results showed that the resulting PDLLA-PDA-CHWs film with well-ordered CHWs coating designed through simple and effective approach has promising application in bone repair material field.
研究领域:
材料科学
·
生物医学工程
·
生物材料
·
组织工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2020
·
IF 3.862
Chi Zhang,Peng Dong,Ying Bai,Daping Quan
The nanofibrous ultrastructure of native extracellular matrix (ECM) provides topological cues for specific cellular behavior, therefore, serves as a physical template for bio-scaffolds design and fabrication. Poly(γ-benzyl- l -glutamate) (PBLG) is a commonly used polypeptide, which often self-assembles into nanofibers. However, the slow degradation of PBLG limits its application in tissue engineering. Herein, poly( D,L- lactide)- b -poly(γ-benzyl- l -glutamate) (P DL LA- b -PBLG) was successfully synthesized. This polyester-polypeptide copolymer underwent nanofibrous self-assembly through quenched thermally induced phase separation (TIPS) and α-helix formation of PBLG segment. It was noted that this block copolymer degraded much faster than PBLG homopolymer, since the degradation mostly occurred to P DL LA segments. A three-dimensional P DL LA- b -PBLG scaffold was then obtained with larger nanofiber sizes and higher porosity than the PBLG scaffold, which was highly cytocompatible and conducive to cell adhesion, spreading and proliferation. For neural tissue engineering applications, the copolymer scaffold was found capable of facilitating neural stem cells differentiation into neuron-like cells. These results suggested that the scaffolds fabricated from P DL LA- b -PBLG with nanofibrous structures held great potential for stem cell transplantation and neural tissue engineering.
研究领域:
生物材料
·
组织工程
·
生物医学工程
·
细胞生物学
✓ 已验证
DOI
高影响因子
International Journal of Nanomedicine
·
2023
·
IF 8
Qi-Wei Fu,Yun-Peng Zi,Wei Xu,Rong Zhou,Zhu-Yun Cai,Wei-Jie Zheng,Feng Chen,Qi-Rong Qian
Calcium phosphate-based biomaterials have been well studied in biomedical fields due to their outstanding chemical and biological properties which are similar to the inorganic constituents in bone tissue. In this study, amorphous calcium phosphate (ACP) nanoparticles were prepared by a precipitation method, and used for preparation of ACP-poly(d,l-lactic acid) (ACP-PLA) nanofibers and water-soluble drug-containing ACP-PLA nanofibers by electrospinning. Promoting the encapsulation efficiency of water-soluble drugs in electrospun hydrophobic polymer nanofibers is a common problem due to the incompatibility between the water-soluble drug molecules and hydrophobic polymers solution. Herein, we used a native biomolecule of lecithin as a biocompatible surfactant to overcome this problem, and successfully prepared water-soluble drug-containing ACP-PLA nanofibers. The lecithin and ACP nanoparticles played important roles in stabilizing water-soluble drug in the electrospinning composite solution. The electrospun drug-containing ACP-PLA nanofibers exhibited fast mineralization in simulated body fluid. The ACP nanoparticles played the key role of seeds in the process of mineralization. Furthermore, the drug-containing ACP-PLA nanofibers exhibited sustained drug release which simultaneously occurred with the in situ mineralization in simulated body fluid. The osteoblast-like (MG63) cells with spreading filopodia were well observed on the as-prepared nanofibrous mats after culturing for 24 hours, indicating a high cytocompatibility. Due to the high biocompatibility, sustained drug release, and fast mineralization, the as-prepared composite nanofibers may have potential applications in water-soluble drug loading and release for tissue engineering.
研究领域:
生物材料
·
药物递送
·
组织工程
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）