POLYMER DEGRADATION AND STABILITY
·
2018
·
IF 3.193
Daokun Shi,Yahong Kang,Guoyi Zhang,Chenguang Gao,Wei Lu,Caihong Yang,Hua Zou,Hongyan Jiang
Three kinds of high molecular weight polymers were synthesized by ring-opening polymerization with various monomer feeding ratios (named as PLLA, PLCL 95/5 and PLGC 80/15/5, respectively). Then oriented monofilament was produced through melt-extrusion and tensile orientation based on each kind of polymer. In vitro degradation properties of the monofilaments were studied over a range of degradation time from 1 to 21 days at 60 °C by using SEM , GPC , DSC , XRD and tensile test . Degradation results showed that the mass loss, T g and morphology integrity of the PLLA monofilament basically remained unchanged, and partial degradation in amorphous region emerged with slight increase of crystallinity . For the PLCL 95/5 monofilament, the crystallinity was increased and the monofilament was fractured at 14 days accompanying with obvious decrease of the mass and T m , indicating that most part of the amorphous region was degraded. Apparently, the PLGC 80/15/5 monofilament showed the fastest degradation rate with considerable mass loss and decrease of T g . The amorphous region was degraded sharply in the early stage due to its good water absorbability and lower structural regularity, and the initially-formed crystalline region was degraded slowly later evidenced from the change of crystallinity and it was fractured at 3 days. The accelerated effects calculated according to the first-order kinetic model demonstrated that the PLCL 95/5 monofilament was degraded 2.5 times faster than pure PLLA and the PLGC 80/15/5 monofilament was degraded 7.5 times faster than PLLA. These were nearly consistent with those based on [ η ] (2.5 and 6.9 times respectively). The comparative study of in vitro degradation behavior of PLLA-based copolymer monofilaments would provide useful information for controlling the monomer composition of PLLA-based materials with specific degradation requirements.
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高影响因子
POLYMER
·
2024
·
IF 4.1
Li Jiang,Cong Yan,Yuan-Ming Zhai,Fei Luo,He Meng,Bo Yin,Kai Zhang,Ming-Bo Yang
Poly(l-lactic acid) (PLLA), recognized as a promising substitute for petroleum-based polymers, has garnered significant attention for its various advantages. However, the practical application of PLLA is limited by its poor toughness. This study introduces a novel approach, using a graft copolymer, poly(vinyl alcohol)-graft-poly(l-lactic acid) (PVA-g-PLLA), synthesized through a "grafting to" method to enhance the compatibility of PLLA/PVA blends. It is demonstrated that even though the graft copolymer promotes crystallization, the resultant ternary blends, especially with a mass ratio of 7:3:1, exhibited an 88.7 % elongation at break, representing a 1642 % improvement over pure PLLA and a 576 % increase over binary PLLA/PVA blends. In addition, incorporating PVA-g-PLLA significantly enhanced the toughness of the PLLA/PVA blends without sacrificing strength, thermal stability, or transparency. Remarkably, the Vicat softening temperature of the blends with a 7/3/1.5 ratio increased to about 94.4 °C, substantially higher than the 59.9 °C observed in PLLA/PVA blends. These findings suggest that the newly developed copolymer and the ternary blends hold substantial promise for creating biodegradable materials that do not compromise performance. It suggests a promising future for these materials in various applications where enhanced durability, thermal stability, and environmental sustainability are crucial.
研究领域:
材料科学
·
生物医学工程
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高影响因子
ACS Applied Nano Materials
·
2026
·
IF 5.5
Cijun Shuai,Bin Zeng,Xiuwen Gao,Gao Pan,Pan He,Fangwei Qi,Shuping Peng
Platinum nanoparticles (Pt NPs) as nanozymes presented great potential in photodynamic antibacterial applications. However, the tendency for aggregation and the presence of bacterial biofilms limit their photodynamic antibacterial efficacy. Herein, Pt NPs were grown in situ on graphene oxide (GO) nanosheets to prepare Pt–GO nanohybrids, which were subsequently blended with poly(l-lactic acid) (PLLA) powder and fabricated into PLLA/Pt–GO scaffolds via laser 3D printing technology. On one hand, GO possessed a high specific surface area, providing a large space for the uniform deposition of Pt NPs. On the other hand, GO had excellent photothermal properties, which not only enhanced the permeability of the bacterial biofilm but also further improved the photodynamic catalytic effect of Pt NPs. Results demonstrated that the scaffold exhibited favorable photothermal stability and transformation efficiency under near-infrared (NIR) light irradiation. Methylene blue degradation and o-phenylenediamine oxidation assays demonstrated that the scaffold exhibited peroxidase-like activity. Antibacterial experiments demonstrated that under NIR light irradiation, the PLLA/Pt–GO group exhibited decreased bacterial colonies, damaged bacterial morphology, enhanced biofilm permeability, elevated intracellular reactive oxygen species (ROS) levels, and increased bacterial protein leakage compared to the ice bath-cooled PLLA/Pt–GO group. These findings indicated that thermal energy enhanced biofilm permeability, facilitated the entry of ROS into bacterial cells, induced protein leakage, and ultimately resulted in bacterial death. In summary, the scaffold demonstrated antibacterial efficacy rates of 94.15% and 91.42% against E. coli and S. aureus, respectively. Therefore, this study holds promise for providing therapeutic strategies for implant-related infections.
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高影响因子
EUROPEAN POLYMER JOURNAL
·
2026
·
IF 6.8
Maosheng Zhang,Lingchen Mao,Suyang Dai,Ni Jiang,Xinggui Gu,Zhihua Gan,Zhenbo Ning
To explore the aggregation behavior of small molecules and macromolecules at different scales, this study employed aggregation-induced emission (AIE) molecule tetraphenylethylene-polyol (TPE-4OH) as a polyol initiator to synthesize four-armed poly( l -lactic acid) (4a-TPE-PLLA) with varied chain lengths. Moreover, comparative studies with pentaerythritol-initiated four-armed PLLA revealed significant mutual regulatory relationships between self-aggregation of TPE groups and PLLA crystallization. Lower glass transition temperatures (48.0°C of 4a-TPE-PLLA-S and 49.4°C of 4a-TPE-PLLA-M) and rheological results indicated that when PLLA chains are short (28 repeating units) or medium (48 repeating units) in length, TPE groups weakened the PLLA interchain interactions and promoted the segmental mobility of of PLLA chains. While longer PLLA chains (78 repeating units) were easier to restrict the conformation of TPE, which showed higher photoluminescence quantum yield (PLQY) values. In-situ polarized microscopy revealed TPE aggregates promoted the nucleation of PLLA. Higher PLQY was observed after 4a-TPE-PLLA crystallization, especially, the PLQY of 4a-TPE-PLLA-M increased from 58.23% to 65.36%. And 4a-TPE-PLLA also showed the potential application of phase separation indicator due to its fluorescence properties. This work provides some insights into the multi-scale aggregation mechanisms of PLLA chains and AIE molecules.
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高影响因子
Regenerative Biomaterials
·
2024
·
IF 5.6
Chen Shuo,Wang Xinqing,Zhang Dong,Huang Zhenhua,Xie Yina,Chen Fangping,Liu Changsheng
Poly (l-lactic acid) (PLLA) is a biocompatible, biodegradable material with piezoelectric properties, making it a promising candidate for providing self-powered stimulation to accelerate tissue repair. Repairs to various tissues, such as bone, cartilage, and nerve, necessitate distinct piezoelectric characteristics even from the same material. However, the extensive utilization of PLLA piezoelectric scaffolds in various tissue is hindered by their low and single piezoelectric constants. In this study, PLLA nanofiber membranes with enhanced and adjustable piezoelectric constants (d33) were fabricated through oriented electrospinning. By carefully controlling the parameters of the spinning solution, a steady increase in d33 values from 0 to 30 pC/N was achieved. This advancement allows tailoring of PLLA nanofiber membranes to meet various piezoelectric requirements of different tissues. As an example of tailoring the optimal piezoelectric constants, we developed PLLA-2-0, PLLA-2-10, PLLA-2-15 and PLLA-2-20 nanofiber membranes with d33 values of 0, 5, 10 and 15 pC/N, respectively. The impact of varying piezoelectric constants of PLLA nanofiber membranes on cellular behavior and repair efficacy were validated through in vitro cellular experiments and in vivo mandibular critical defect repair. The results indicated that PLLA-2-20 demonstrated superior cell proliferation rate up to 130% and an osteogenic differentiation level approximately twice of the control. In addition, PLLA-2-20 significantly promoted cell adhesion and migration, and the cell aspect ratio was about 5 times higher than that of the control group. In vivo, PLLA-2-20 optimal restorative effects on rat mandibles via endogenous mechanical force-mediated piezoelectric stimulation, leading to complete histological restoration within 8 weeks. These findings highlight the potential of the PLLA membranes with high and adjustable d33 by a straightforward process. This study provides a novel approach for the development of highly electroactive membranes tailored to specific tissue repair needs.
研究领域:
生物材料学
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组织工程学
·
再生医学
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DOI
PubMed
高影响因子
Journal of Functional Biomaterials
·
2026
·Vol. 17
·期 2
·71
·
IF 5.2
Siqi Zhang,Yuan Gao,Danyang Wang,Yongjie Chi,Fang Wu,Lianyan Wang,Hailan Jin
Skin aging could lead to dermal collagen loss and elastic fiber degradation, ultimately manifesting as skin laxity. We aimed to counteract this by using poly-L-lactic acid (PLLA) microsphere (MS)-based fillers to facilitate long-term volume restoration through collagen regeneration. However, conventional MSs exhibit limitations such as broad size distribution and surface irregularities, which are frequently associated with significant adverse reactions. This study employed shirasu porous glass (SPG) membrane emulsification to fabricate uniform and well-shaped polyethylene glycol-block-poly (L-lactic acid) (PEG-PLLA) MSs. A single-factor experiment was employed to optimize the parameters. The optimal preparation conditions for PEG-PLLA MSs were as follows: PEG-PLLA concentration of 40 mg/mL, polyvinyl alcohol (PVA) concentration of 0.5%, and magnetic stirring speed of 200 rpm. Under the optimal conditions, the average particle size of PEG-PLLA MSs was 58.982 μm, and the span value (SPAN) was 1.367. In addition, a cytotoxicity assay was performed, and the results revealed no significant toxicity of the MSs toward L929 mouse fibroblasts at concentrations below 500 μg/mL. Furthermore, PEG-PLLA MSs significantly enhanced the production of key extracellular matrix (ECM) components—type I collagen (Col-I), type III collagen (Col-III), and hyaluronic acid (HA)—while simultaneously alleviating cellular oxidative stress responses. This work offers a reliable and reproducible fabrication strategy for developing biocompatible MS fillers with controllable particle sizes.
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PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 22
·16940-16949
·
IF 3.84
Rui Zhao,Xiang Li,Bolun Sun,Yan Tong,Ziqiao Jiang,Ce Wang
The ideal wound dressing should achieve rapid healing with hemostasis, antimicrobial activity, maintenance of a moist wound bed, etc. The electrospun blend mat meets the requirements outlined for wound healing, by their microfibrous structures providing a suitable environment for wound healing. In this study, a dual-layer nanofiber blend mat wound dressing of nitrofurazone (NFZ)-loaded poly(L-lactide) (PLLA)/sericin nanofibers and NFZ-loaded PLLA nanofibers is fabricated by electrospinning. The NFZ-loaded PLLA/sericin nanofibers act as the first layer and then the NFZ-loaded PLLA nanofibers are the second layer to prepare the dual-layer fiber dressings. The prepared dual-layer NFZ-loaded fiber dressings have satisfactory antibacterial activity against both Gram-positive and Gram-negative bacteria. In vitro drug release studies show that the drug release profiles can be controlled by adjusting the drug amount in different layers of the dual-layer dressings. The methyl thiazolyl tetrazolium (MTT) assays demonstrate that the NFZ-loaded PLLA/sericin fibers are nontoxic and biocompatible. In vivo wound healing tests are performed in rats. The results reveal that the dual-layer fiber dressings perform better than commercial non-woven dressing in decreasing wound size. It is observed at 12 days that the wound size reduction is 97% for being dressed with the dual-layer fiber dressings but 84% for the commercial woven dressing. These NFZ-loaded PLLA/sericin‖PLLA dual-layer fiber mats may provide a promising candidate for accelerating wound healing.
研究领域:
生物材料
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医学工程
·
药学
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高影响因子
JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION
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2020
·
IF 2.69
Jianping Mao,Pengfei Wei,Zuoying Yuan,Wei Jing,Jingjing Cao,Guangping Li,Jianxun Guo,Honggang Wang,Dafu Chen,Qing Cai
There are intensive needs for scaffolds with new designs to meet the diverse requirements of bone repairing. Biodegradable microspheres are highlighted as injectable micro-scaffolds thanks to their advantages in filling irregular defects via a minimally invasive surgery. In this study, microspheres with surface micropores were made via the W1/O/W2 double emulsion method using amphiphilic triblock copolymers (PLLA-PEG-PLLA) composed of poly(L-lactide) (PLLA) and poly(ethylene glycol) (PEG) segments. When the PEG fraction was controlled as 10 wt.%, the microspheres demonstrated higher cell affinity than the smooth-surfaced PLLA microspheres. After being further functionalized with polydopamine coating and apatite deposition, the PLLA-PEG-PLLA microspheres could up-regulate the osteogenic differentiation of bone marrow mesenchymal stromal cells (BMSCs) significantly. Before subcutaneous implantation, bone morphogenetic protein-2 (BMP-2) was adsorbed onto the biomineralized microspheres by taking advantages of the strong affinity of apatite to BMP-2. The resulted microspheres induced ectopic osteogenesis efficiently without causing biocompatibility problems. In summary, this study provided a simple strategy to prepare functionalized microspheres with osteoconductivity and osteoinductivity, which showed great potential in promoting bone regeneration as injectable micro-scaffolds.
研究领域:
生物医学工程
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组织工程
·
材料科学
·
再生医学
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DOI
PubMed
高影响因子
International Journal of Nanomedicine
·
2023
·
IF 8
Wei Nie,Yiming Gao,David James McCoul,Gregory James Gillispie,YanZhong Zhang,Li Liang,ChuangLong He
Introduction: Hierarchical nanofibrous scaffolds are emerging as a promising bone repair material due to their high cell adhesion activity and nutrient permeability. However, the existing method for hierarchical nanofibrous scaffolds fabrication is complicated and not perfectly suitable for further biomedical application in view of both structure and function. In this study, we constructed a hierarchical nanofibrous poly (l-lactic acid)/poly(ε-caprolactone) (PLLA/PCL) scaffold and further evaluated its bone healing ability.Methods: The hierarchical PLLA/PCL nanofibrous scaffold (PLLA/PCL) was prepared by one-pot TIPS and then rapidly mineralized at room temperature by an electrochemical deposition technique. After electrode-positioning at 2 V for 2 hrs, a scaffold coated with hydroxyapatite (M-PLLA/PCL) could be obtained.Results: The pore size of the M-PLLA/PCL scaffold was hierarchically distributed so as to match the biophysical structure for osteoblast growth. The M-PLLA/PCL scaffold showed better cell proliferation and osteogenesis activity compared to the PLLA/PCL scaffold. Further in vivo bone repair studies indicated that the M-PLLA/PCL scaffold could accelerate defect healing in 12 weeks.Conclusion: The results of this study implied that the as-prepared hydroxyapatite coated hierarchical PLLA/PCL nanofibrous scaffolds could be developed as a promising material for efficient bone tissue repair after carefully tuning the TIPS and electrodeposition parameters.
研究领域:
材料科学
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生物医学工程
·
组织工程
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PubMed
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2025
·
IF 5.4
Decong Kong,Meiqi Song,Yonghong Pan,Xierzhati Aimaier,Ye Tian,Rui Yang,Jing Huang,Yi Liu,Xiaomei Liu,Nikolai Boshkov,Botao Zhang,Hua Li
In this study, the interface-modified ternary blends based on polylactic acid (PLLA)-polycaprolactone (PCL)-polycarbonate diols (PCDL) were prepared via suspension flame spray. Morphological analysis showed that the interface modification of PCDL significantly improves the compatibility of PLLA and PCL. Mechanical analysis revealed that the addition of PCDL resulted in great enhancement of the toughness of the PLLA/PCL composite coatings with a dramatic 326 % increase of the fracture strain for 10PLLA/90PCL/10PCDL compared with 10PLLA/90PCL. Further physicochemical and antibacterial test revealed no significant difference among PLLA/PCL and PLLA/PCL/CAM composite coatings with and without PCDL. Time-course release analysis showed that the release mechanism of the composite coating generally remains the same when the PCDL added is lower than the main components in PLLA/PCL, and even changed from the original abnormal diffusion to Fick diffusion. Overall, the ternary blending approach of PLLA-PCL-PCDL using suspension flame spray is a promising technique with great potential drug-delivery applications with different mechanical requirements.
研究领域:
材料科学
·
生物医学工程
·
制药工程
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DOI
高影响因子
Regenerative Biomaterials
·
2024
·
IF 5.6
Hu Zhaofan,Zhang Yunyang,Zhang Jingjing,Zheng Ran,Yang Yang,Kong Fei,Li Haoran,Yang Xinyan,Yang Shuhui,Kong Xiangdong,Zhao Ruibo
Biomineralization-based cell-material living composites ex vivo showed great potential for living materials construction and cell regulation. However, cells in scaffolds with unconnected pores usually induce confined nutrient transfer and cell–cell communications, affecting the transformation of osteoblasts into osteocytes and the mineralization process. Herein, the osteoblast-materials living hybrids were constructed with porous PLLA microspheres using a rational design, in which cell-based living materials presented an improved osteoblast differentiation and mineralization model using rationally designed cell-microsphere composites. The results indicated that the microfluidic-based technique provided an efficient and highly controllable approach for producing on-demand PLLA microspheres with tiny pores (<5 μm), medium pores (5–15 μm) and large pores (>15 μm), as well as further drug delivery. Furthermore, the simvastatin (SIM)-loaded porous PLLA microsphere with ε-polylysine (ε-PL) modification was used for osteoblast (MC3T3-E1) implantation, achieving the cell-material living microhybrids, and the results demonstrated the ε-PL surface modification and SIM could improve osteoblast behavior regulation, including cell adhesion, proliferation, as well as the antibacterial effects. Both in vitro and in vivo results significantly demonstrated further cell proliferation, differentiation and cascade mineralization regulation. Then, the quantitative polymerase chain reaction or histological staining of typical markers, including collagen type I, alkaline phosphatase, runt-related transcription factor 2 and bone morphogenetic protein 2, as well as the calcium mineral deposition staining in situ, reconfirmed the transformation of osteoblasts into osteocytes. These achievements revealed a promising boost in osteogenesis toward mineralization at the microtissue level by cell-microsphere integration, suggesting an alternative strategy for materials-based ex vivo tissue construction and cell regulation, further demonstrating excellent application prospects in the field of biomineralization-based tissue regeneration.
研究领域:
组织工程
·
再生医学
·
生物材料学
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PubMed
高影响因子
POLYMER SCIENCE SERIES A
·
2017
·Vol. 59
·期 1
·116-123
·
IF 0.822
Shao Jun,Guo Yanmei,Ye Sitong,Xie Baomei,Xu Yaoyin,Hou Haoqing
The linear poly( L -lactide) and poly( D -lactide) (PLLA, PDLA) with relative lower molecular weights were synthesized, and PLLA/PDLA blends at various content of PDLA were prepared by solution casting. The morphology and growth of poly(lactide) stereocomplex (PLA SC) were investigated by polarized optical microscope. Results revealed that the morphology of SC in the blends strongly depended on the content of PDLA and the annealing temperature. Dendritic and irregular SC with looser structure developed in the specimens with lower content of PDLA, and regular SC spherulites with birefringent and compact structure produced in the specimens with higher content of PDLA. The growth rate ( G ) of SC increased gradually as the content of PDLA enhanced in the blends. As the annealing temperature enhanced, the SC with brighter and more compact structure appeared. The G value increased at first before declining as the annealing temperature elevated from the 130 to 190°C. And the nonlinear behavior of the growth of SC in the dissimilar specimens was analyzed.
研究领域:
材料科学
·
高分子化学
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高影响因子
危险品化学品经营许可证（带存储）