Polymers
·
2021
·Vol. 13
·期 8
·1270
·
IF 4.329
Mengyuan Zhang,Zhonghua Chang,Xiaofeng Wang,Qian Li
Biodegradable and bioabsorbable polymers have drawn considerable attention because of their mechanical properties that mimic human soft tissue. Poly(l-lactide-co-ε-caprolactone) (PLCL), the copolymer of L-lactic (LA) and ε-caprolactone (CL), has been applied in many tissue engineering and regenerative medicine fields. However, both the synthesis of PLCL and the structure-activity relationship of the copolymer need to be further investigated to allow tuning of different mechanical properties. The synthesis conditions of PLCL were optimized to increase the yield and improve the copolymer properties. The synthetic process was evaluated by while varying the molar ratio of the monomers and polymerization time. The mechanical properties of the copolymer were investigated from the macroscopic and microscopic perspectives. Changes in the polymerization time and feed ratio resulted in the difference in the LA and CL content, which, in turn, caused the PLCL to exhibit different properties. The PLCL obtained with a feed ratio of 1:1 (LA:CL) and a polymerization time of 30 h has the best toughness and elasticity. The developed PLCL may have applications in dynamic mechanical environment, such as vascular tissue engineering.Keywords:poly(l-lactide-co-ε-caprolactone);synthesis;segment;toughness;elasticity
研究领域:
生物材料学
·
组织工程学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Frontiers in Bioengineering and Biotechnology
·
2023
·
IF 5.7
Song Baiyang,Fang Li,Mao Xufeng,Ye Xianwang,Yan Zejun,Ma Qi,Shi Zewen,Hu Yiwei,Zhu Yabin,Cheng Yue
Introduction: The repair of a diseased ureter is an urgent clinical issue that needs to be solved. A tissue-engineered scaffold for ureteral replacement is currently insufficient due to its incompetent bioactivity, especially in long-segment abnormalities. The primary reason is the failure of urothelialization on scaffolds.Methods: In this work, we investigated the ability of gelatin-grafted tubular scaffold in ureteral repairment and its related biological mechanism. We designed various porous asymmetric poly (L-lactic acid) (PLLA)/poly (L-lactide-co-e-caprolactone) (PLCL) tubes with a thermally induced phase separation (TIPS) method via a change in the ratio of solvents (named PP). To regulate the phenotype of urothelial cells and ureteral reconstruction, gelatin was grafted onto the tubular scaffold using ammonolysis and glutaraldehyde crosslinking (named PP-gel). The in vitro and in vivo experiments were performed to test the biological function and the mechanism of the scaffolds.Results and Discussion: The hydrophilicity of the scaffold significantly increased after gelatin grafting, which promoted the adhesion and proliferation of urothelial cells. Through subcutaneous implantation in rats, PP-gel scaffolds demonstrated good biocompatibility. The in vivo replacement showed that PP-gel could improve urothelium regeneration and maintain renal function after the ureter was replaced with an ∼4 cm-long PP-gel tube using New Zealand rabbits as the experimental animals. The related biologic mechanism of ureteral reconstruction was detected in detail. The gelatin-grafted scaffold upgraded the integrin α6/β4 on the urothelial cell membrane, which phosphorylates the focal adhesion kinase (FAK) and enhances urothelialization via the MAPK/Erk signaling pathway.Conclusion: All these results confirmed that the PP46-gel scaffold is a promising candidate for the constitution of an engineered ureter and to repair long-segment ureteral defects.
研究领域:
生物医学工程
·
组织工程
·
泌尿外科
·
细胞生物学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2022
·Vol. 31
·期 1
·1-12
·
IF 4.705
Yuan Yuka,Fu Zhe,Liu Yudong,Liu Kai,Hua Jing
Poly (L-lactic acid) (PLLA) suggests attractive biomedical applications in drug releasing system, surgical suture, bone fixing and tissue repairing due to its degradable and biocompatible benefits. However, currently developed catalysts with high toxicity and currently reported PLLA with uncontrollable crystallinity are detrimental for the environmental protection and human health. Herein, we proposed a novel and effective approach to synthesizing PLLA using environmentally-friendly bio-based phenol-substituted triisobutylaluminum as the catalyst. The effects of the chemical structures of various bio-based phenols on the polymerization activity and stereoregularity of PLLA were explored in detail. The increased steric hindrance of bio-based phenols was beneficial for the polymerization activity of PLLA. The resultant PLLA exhibited an ultrahigh monomer conversion efficiency up to 98.32% among the highest value of reported PLLA. Moreover, the PLLA also demonstrated quick polymerization rate (< 5 h) and low polymerization temperature (< 100 °C), with controllable polymer crystallinity (36 ~ 46%) and number average molecular weight (8400 ~ 16,000 g mol −1 ). Consequently, the strategy and results collectively represent a significant advance toward the preparation of high-performance degradable and biocompatible PLLA.
研究领域:
材料科学
·
生物医学工程
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2012
·Vol. 19
·期 12
·1-8
·
IF 1.733
Ma Chi,Wang Bing,Xiong Cheng-Dong,Chen Dong-Liang,Xiong Zuo-Chun
Control of dimensional stability is crucial for using electrospun membranes in biomedical and tissue engineering applications. In this study, the contraction of electrospun membranes of poly( l -lactide-co-glycolide) (PLLGA) after stretch was investigated. Then, by adding PLLGA-b-polyethylene glycol (PLLGA-PEG), the contraction of the membranes was controlled. In addition, the mechanical properties of the membranes were investigated. On the basis of the strain–stress behavior of the membranes, an elongation of 50 % was used to investigate the orientation degrees of the membrane fibers. On the basis of the morphology of the stretched membranes, the contraction was found to depend on the orientation degree of fibers after stretch. A linear relationship between the contraction and degree of orientation after stretch was confirmed. Two-dimensional fast Fourier transform (2D FFT) analysis of the scanning electron microscopy (SEM) images of the membranes was used to quantify the orientation degree. It was surmised that the different orientation degrees were responsible for the different morphologies and thermal behaviors of the membranes.
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
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
Materials
·
2016
·Vol. 9
·期 5
·368
·
IF 2.728
Ying Wang,Li-Hui Zhu,Ai-Zheng Chen,Qiao Xu,Yu-Juan Hong,Shi-Bin Wang
A one-step method using a high-voltage electrostatic anti-solvent process was employed to fabricate poly-l-lactide (PLLA) porous microspheres (PMs). To address the simplification and control of the preparation process, a 24full factorial experiment was performed to optimize the operating process and analyze the effect of the factors on the morphology and aerodynamic properties of the PLLA PMs, and various characterization tests were also performed. The resulting PLLA PMs exhibited an even and porous morphology with a density less than 0.4 g/cm3, a geometric mean diameter (Dg) of 10–30 μm, an aerodynamic diameter (Da) of 1–5 μm, a fine particle fraction (FPF) of 56.3%, and a porosity of 76.2%, meeting the requirements for pulmonary drug delivery. The physicochemical characterizations reveal that no significant chemical change occurred in the PLLA during the process. An investigation of itsin vitrocytotoxicity and pulmonary toxicity shows no obvious toxic response, indicating good biosafety. This study indicates that the one-step method using a high-voltage electrostatic anti-solvent process has great potential in developing an inhalable drug carrier for pulmonary drug delivery.Keywords:poly-l-lactide;porous microspheres;aerodynamic properties;pulmonary drug delivery;biosafety
研究领域:
药学
·
材料科学
·
生物医学工程
✓ 已验证
DOI
PubMed
高影响因子
Regenerative Biomaterials
·
2021
·Vol. 8
·期 5
·
IF 6.353
Liu Boxun,Jin Zhizhong,Chen Haiyan,Liang Lun,Li Yao,Wang Guo,Zhang Jing,Xu Tao
Electrospun membranes are attracting interest as a drug delivery system because of their material composition flexibility and versatile drug loading. In this study, the electrospun membrane was loaded with doxorubicin (DOX) via electrostatic adsorption for long-term drug delivery. DOX loading process was optimized by varying temperature, time, drug concentration, pH and ionic strength of solutions. The loading process did not impair the structural properties of the membrane. Next, we investigated the drug release kinetics using spectroscopic techniques. The composite membranes released 22% of the adsorbed DOX over the first 48 h, followed by a slower and sustained release over 4 weeks. The DOX release was sensitive to acidic solutions that the release rate at pH 6.0 was 1.27 times as that at pH 7.4. The DOX-loaded membranes were found to be cytotoxic to U-87 MG cells in vitro that decreased the cell viability from 82.92% to 25.49% from 24 to 72 h of co-incubation. These membranes showed strong efficacy in suppressing tumour growth in vivo in glioblastoma-bearing mice that decreased the tumour volume by 77.33% compared with blank membrane-treated group on Day 20. In conclusion, we have developed an effective approach to load DOX within a clinically approved poly (L-lactic acid)/gelatine membrane for local and long-term delivery of DOX for the treatment of glioblastoma.
研究领域:
药理学
·
肿瘤学
·
生物材料科学
·
药物递送系统
✓ 已验证
DOI
PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Feng Su,Peng Yun,Chenglong Li,Rongye Li,Laishun Xi,Yuandou Wang,Yangsheng Chen,Suming Li
A series of poly(2-ethyl-2-oxazoline)-poly(L-lactide) (PEOz-PLA) diblock copolymers were synthesized by ring-opening polymerization of l -lactide using a monohydroxy terminated PEOz-OH macro-initiator in the presence of stannous octoate as catalyst. The resulting diblock copolymers were characterized by 1 H nuclear magnetic resonance and gel permeation chromatography . Self-assembled micelles were prepared using the co-solvent evaporation method in water and in phosphate buffered saline (PBS) at pH 7.4, 6.5 and 5.0. The resulting micelles exhibit different morphologies, such as spherical micelles and worm-like micelles depending on the hydrophilic/hydrophobic balance. Spherical micelles were exclusively observed for PEOz-PLA copolymers with short PLA blocks, whereas co-existence of worm-like and spherical micelles was observed for copolymers with long PLA blocks. The micelle size increases with decreasing pH due to the electrostatic repulsion between PEOz chains resulting from ionization of the tertiary amide groups along PEOz chains. A hydrophobic anti-tumor drug, paclitaxel , was entrapped in PEOz-PLA micelles. High loading efficiency up to 86.7% was obtained for copolymers with long PLA blocks. Drug release was performed in PBS at different pH values. During the 30-day release period, faster release was obtained for copolymers with shorter PLA blocks than for copolymers with longer PLA blocks, at acidic pH than at pH 7.4. It is thus concluded that pH-responsive PEOz-PLA copolymer micellss could be promising as carrier of anti-tumor drugs.
研究领域:
生物材料学
·
药剂学
·
高分子化学
✓ 已验证
DOI
高影响因子
JOURNAL OF BIOACTIVE AND COMPATIBLE POLYMERS
·
2015
·
IF 2.352
Yuan Yao,Haifeng Liu,Xili Ding,Xiaohui Jing,Xianghui Gong,Gang Zhou,Yubo Fan
In recent years, silk fibroin has become one of the most promising tissue engineering materials because of its excellent cytocompatibility. Poly(l-lactide-co-ε-caprolactone), the copolymer of poly(l-lactide) and poly(ε-caprolactone), possesses good mechanical properties, and its degradation rates can be manipulated by varying the ratio of the constituent polymers. In this study, in order to combine their respective characteristics, silk fibroin/poly(l-lactide-co-ε-caprolactone) nanofibrous membranes were fabricated through electrospinning with different mass ratios of 100:0, 75:25, 50:50, 25:75, and 0:100. The surface properties, thermodynamic properties, mechanical properties, and cytocompatibility of silk fibroin/poly(l-lactide-co-ε-caprolactone) blended membranes were evaluated, and an optimal blending ratio was identified. The results showed that the silk fibroin/poly(l-lactide-co-ε-caprolactone) blended membranes containing 75% of silk fibroin and 25% of poly(l-lactide-co-ε-caprolactone) achieved the most improved performances compared with the single-component membranes or the blended membranes with other mixing ratios. The results from this study indicated that 75/25 silk fibroin/poly(l-lactide-co-ε-caprolactone) blended membranes which combined the advantages of poly(l-lactide-co-ε-caprolactone) and silk fibroin might be a suitable candidate material for use in tissue engineering.
研究领域:
生物材料
·
组织工程
·
材料科学
·
生物医学工程
✓ 已验证
DOI
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
·
材料工程
·
纳米复合材料
·
结晶动力学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2020
·
IF 4.389
Anlin Yin,Weihua Zhuang,Gongyan Liu,Xiaorong Lan,Zhonglan Tang,Yan Deng,Yunbing Wang
The fabrication of a functional small-diameter vascular graft with good biocompatibility, in particular hemocompatibility, has become an urgent clinical necessity. We fabricated a native bilayer, small-diameter vascular graft using PEGylated chitosan (PEG-CS) and poly (L-lactic acid-co-ε-caprolactone; PLCL). To stabilize the inner layer, a PEG-CS blend with PLCL at ratio of 1:6 was casted on a round metal bar by a drip feed, and the outer layer, a PLCL blend with water-soluble PEG that acted as a sacrificial part to enhance pore size, was fabricated by electrospinning. The results showed excellent hemocompatibility and strong mechanical properties. In vitro , the degradation of the graft was evaluated by measuring the graft structure, mass loss rate, and changes in molecular weight. The results indicated that the graft had adequate support for the regeneration of blood vessels before collapse. An in vivo study was performed in a canine femoral artery model for up to 24 weeks, which demonstrated that the PEGylated bilayer grafts possessed excellent structural integrity, high compatibility with blood, good endothelial cell (EC) and smooth muscle cell (SMC) growth, and high expression levels of angiogenesis-related proteins, features that are highly similar to autologous blood vessels. Moreover, the results showed almost negligible calcification within 24 weeks. These findings confirm that the bilayer graft mimics native cells, thereby effectively improving vascular remodeling.
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
PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
·
2017
·
IF 4.164
Heyu Li,Gareth R. Williams,Junzi Wu,Haijun Wang,Xiaozhu Sun,Li-Min Zhu
In this work, we aimed to develop new materials to reduce the secondary injuries which can be imparted when replacing wound dressings. Electrospun fibers based on the thermoresponsive polymer poly( N -isopropylacrylamide) (PNIPAAm), poly( l -lactic acid- co -ɛ-caprolactone) (PLCL), and the antibiotic ciprofloxacin (CIF) were prepared. The water contact angle of fibers made from a blend of PNIPAAm and PLCL changed dramatically when the temperature was increased above 32 °C. Sustained release of CIF from the formulations was observed over > 200 h. Moreover, L929 fibroblasts could proliferate on the fibers, indicating their biocompatibility. The CIF-loaded fibers were found to have potent antibacterial activity against E . coli and S . aureus . In vivo tests on rats indicated that CIF-loaded thermosensitive fibers have enhanced healing performance compared to CIF-loaded PLCL fibers or a commercial gauze. Electrospun PNIPAAm/PLCL fibers loaded with CIF thus have great promise in the development of new wound dressing materials.
研究领域:
生物材料学
·
药剂学
·
组织工程学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）