Self-healing poly（urea-urethane）s （PUUs） showing a tolerance to mechanical damage are particularly desirable for high-performance elastomeric biomaterials. In this study a kind of biodegradable PUUs was synthesize...Self-healing poly（urea-urethane）s （PUUs） showing a tolerance to mechanical damage are particularly desirable for high-performance elastomeric biomaterials. In this study a kind of biodegradable PUUs was synthesized from poly（e-caprolactone） diol with L-lysine ethyl ester diisocyanate （LDI） extended with L-lysine ethyl ester dihydrochloride （LEED） in DMF and characterized by using 1H-NMR, FTIR, DSC, XRD, SEM and tensile tests. Interestingly, they exhibited a self-healing characteristic upon exposure to 37℃ for as short as 30 min with the tensile strength keeping at 4.23 MPa and the elongation at break reaching to 627%. It is revealed that increasing the hard segment content in PUUs benefits the self-healing performance, and on the opposite increasing the soft segment content contributes to the biodegradability.展开更多
Lamellar structures of banded spherulites of poly(e-caprolactone)/poly(vinylchloride) (PCL/PVC) blends are observed using tapping mode atomic force microscopy (AFM). Thesurface of the PCL/PVC banded spherulites presen...Lamellar structures of banded spherulites of poly(e-caprolactone)/poly(vinylchloride) (PCL/PVC) blends are observed using tapping mode atomic force microscopy (AFM). Thesurface of the PCL/PVC banded spherulites presents to be concentric periodic ups and downs. Theperiod of the bands corresponds to the extinction rings under the polarized optical microscopyobservation. The lamellae with edge-on orientation in the ridges and the flat-on lamellae in thevalleys of the banded spherulites are observed clearly. The twisting between the edge-on and flat-onlamellae is also observed.展开更多
从吉林市化工厂污水处理车间排出的活性污泥中筛选出1株可高效降解聚己内酯(PCL)的菌株DS0801。通过形态学观察、生理生化指标检测和16S r DNA系统发育分析,鉴定该菌株为铜绿假单胞菌(Pseudomonas aeruginosa)。菌株培养36 h后,其解聚...从吉林市化工厂污水处理车间排出的活性污泥中筛选出1株可高效降解聚己内酯(PCL)的菌株DS0801。通过形态学观察、生理生化指标检测和16S r DNA系统发育分析,鉴定该菌株为铜绿假单胞菌(Pseudomonas aeruginosa)。菌株培养36 h后,其解聚酶酶活力达到最高峰。研究了该菌株对PCL薄膜的降解行为,结果表明:菌株在发酵7 d时可达到对PCL膜的完全降解,采用扫描电子显微镜对降解到不同程度的PCL膜进行表面形态结构的观察,推测菌株对PCL的降解遵循由表层平面到深层的立体降解过程。质谱检测显示酶降解PCL的产物为ε-己内酯单体。展开更多
Multiwalled carbon nanotubes(MWCNTs) grafted with poly(L-lactide-e-caprolactone)(PCLA) were synthesized by ring opening polymerization reaction and used as a reinforcement for neat PCLA.Scanning electron microscopy(SE...Multiwalled carbon nanotubes(MWCNTs) grafted with poly(L-lactide-e-caprolactone)(PCLA) were synthesized by ring opening polymerization reaction and used as a reinforcement for neat PCLA.Scanning electron microscopy(SEM) revealed that the applied tensile load on the composite was transferred to the MWNT-OH-g-PCLA,loading to a strain failure of the MWCNTs rather than an adhesive failure between the MWCNTs and the matrix.展开更多
Poly(e-caprolactone) (PCL) with weight-average molar mass over 10000 g/mol was synthesized by microwave-assisted ring-opening polymerization of e-caprolactone (e-CL) with maleic acid (MA) as initiator (2.45 GHz, 360 W...Poly(e-caprolactone) (PCL) with weight-average molar mass over 10000 g/mol was synthesized by microwave-assisted ring-opening polymerization of e-caprolactone (e-CL) with maleic acid (MA) as initiator (2.45 GHz, 360 W, 85 min). Ibuprofen-PCL controlled release system was prepared directly by the ROP of e-CL in its mixture with ibuprofen. The release of ibuprofen from the system was sustained and steady.展开更多
Mismatched biomechanical properties between artificial vascular grafts and native blood vessels can result in intimal hyperplasia,especially for the implantation of small-diameter blood vessels.Ideal biomaterials for ...Mismatched biomechanical properties between artificial vascular grafts and native blood vessels can result in intimal hyperplasia,especially for the implantation of small-diameter blood vessels.Ideal biomaterials for vascular repair still remain challenged.Biodegradable poly(ε-caprolactone)(PCL)has been applied for the preparation of electrospun vascular grafts,but more efforts are needed to improve its compliance with tissue growth.Herein,L-arginine-based poly(ester urethane)urea(PEUU)with both elasticity and biodegradability was synthesized so as to enhance the biomechanical properties of vascular grafts by blending electrospinning with PCL in a given mass ratio.It was exhibited that the prepared electrospun PCL/PEUU fibrous membranes were suitable for cell proliferation with normal cell morphology.More importantly,the electrospun membrane with 1/1 mass ratio of PCL/PEUU(PEUU50)showed specific flexibility,exhibiting more suitable mechanical properties matching to the native blood vessels.Specifically,the PEUU50 electrospun membrane demonstrated significantly lower Young’s modulus(9.3±0.8 MPa)and tensile strength(6.0±0.5 MPa),and extremely higher elongation(389%±24%)in wet state than those(16.3±3.0 MPa,11.4±7.1 MPa and 196%±57%,respectively)of the pristine PCL membrane.Overall,this study demonstrated the great potential of amino acid-based PEUUs for the application in small-diameter vascular grafts.展开更多
基金financially supported by the "863" Project of Minister of Science and Technology of China(No. 2007AA021905)
文摘Self-healing poly（urea-urethane）s （PUUs） showing a tolerance to mechanical damage are particularly desirable for high-performance elastomeric biomaterials. In this study a kind of biodegradable PUUs was synthesized from poly（e-caprolactone） diol with L-lysine ethyl ester diisocyanate （LDI） extended with L-lysine ethyl ester dihydrochloride （LEED） in DMF and characterized by using 1H-NMR, FTIR, DSC, XRD, SEM and tensile tests. Interestingly, they exhibited a self-healing characteristic upon exposure to 37℃ for as short as 30 min with the tensile strength keeping at 4.23 MPa and the elongation at break reaching to 627%. It is revealed that increasing the hard segment content in PUUs benefits the self-healing performance, and on the opposite increasing the soft segment content contributes to the biodegradability.
基金supported by the National Natural Science Foundation of China(Grant Nos.20174049 and 20131160730)
文摘Lamellar structures of banded spherulites of poly(e-caprolactone)/poly(vinylchloride) (PCL/PVC) blends are observed using tapping mode atomic force microscopy (AFM). Thesurface of the PCL/PVC banded spherulites presents to be concentric periodic ups and downs. Theperiod of the bands corresponds to the extinction rings under the polarized optical microscopyobservation. The lamellae with edge-on orientation in the ridges and the flat-on lamellae in thevalleys of the banded spherulites are observed clearly. The twisting between the edge-on and flat-onlamellae is also observed.
基金Funded by the National Basic Research Program of China(No.2006CB708609)the Development Program for Outstanding Young Teachers in HIT (HITQNJS.2007.015)
文摘Multiwalled carbon nanotubes(MWCNTs) grafted with poly(L-lactide-e-caprolactone)(PCLA) were synthesized by ring opening polymerization reaction and used as a reinforcement for neat PCLA.Scanning electron microscopy(SEM) revealed that the applied tensile load on the composite was transferred to the MWNT-OH-g-PCLA,loading to a strain failure of the MWCNTs rather than an adhesive failure between the MWCNTs and the matrix.
基金This work was financially supported by the Research Foundation of MOE and National 973 Project of China (G1999064703).
文摘Poly(e-caprolactone) (PCL) with weight-average molar mass over 10000 g/mol was synthesized by microwave-assisted ring-opening polymerization of e-caprolactone (e-CL) with maleic acid (MA) as initiator (2.45 GHz, 360 W, 85 min). Ibuprofen-PCL controlled release system was prepared directly by the ROP of e-CL in its mixture with ibuprofen. The release of ibuprofen from the system was sustained and steady.
基金supported by the National Natural Science Foundation of China(Grant No.52073204)。
文摘Mismatched biomechanical properties between artificial vascular grafts and native blood vessels can result in intimal hyperplasia,especially for the implantation of small-diameter blood vessels.Ideal biomaterials for vascular repair still remain challenged.Biodegradable poly(ε-caprolactone)(PCL)has been applied for the preparation of electrospun vascular grafts,but more efforts are needed to improve its compliance with tissue growth.Herein,L-arginine-based poly(ester urethane)urea(PEUU)with both elasticity and biodegradability was synthesized so as to enhance the biomechanical properties of vascular grafts by blending electrospinning with PCL in a given mass ratio.It was exhibited that the prepared electrospun PCL/PEUU fibrous membranes were suitable for cell proliferation with normal cell morphology.More importantly,the electrospun membrane with 1/1 mass ratio of PCL/PEUU(PEUU50)showed specific flexibility,exhibiting more suitable mechanical properties matching to the native blood vessels.Specifically,the PEUU50 electrospun membrane demonstrated significantly lower Young’s modulus(9.3±0.8 MPa)and tensile strength(6.0±0.5 MPa),and extremely higher elongation(389%±24%)in wet state than those(16.3±3.0 MPa,11.4±7.1 MPa and 196%±57%,respectively)of the pristine PCL membrane.Overall,this study demonstrated the great potential of amino acid-based PEUUs for the application in small-diameter vascular grafts.
