The field of bone tissue engineering has experienced an increase in prevalence due to the inherent challenge of the natural regeneration of significant bone deformities.This investigation focused on the preparation of...The field of bone tissue engineering has experienced an increase in prevalence due to the inherent challenge of the natural regeneration of significant bone deformities.This investigation focused on the preparation of Three-Dimensional(3D)-printed Polycaprolactone(PCL)scaffolds with varying proportions of Nanohydroxyapatite(NHA)and Nanoclay(NC),and their physiochemical and biological properties were assessed.The mechanical properties of PCL are satisfactory;however,its hydrophobic nature and long-term degradation hinder its use in scaffold fabrication.NHA and NC have been employed to improve the hydrophilic characteristics,mechanical strength,adhesive properties,biocompatibility,biodegradability,and osteoconductive behavior of PCL.The morphology results demonstrated 3D-printed structures with interconnected rectangular macropores and proper nanoparticle distribution.The sample containing 70 wt%NC showed the highest porosity(65.98±2.54%),leading to an increased degradation rate.The compressive strength ranged from 10.65±1.90 to 84.93±9.93 MPa,which is directly proportional to the compressive strength of cancellous bone(2–12 MPa).The wettability,water uptake,and biodegradability of PCL scaffolds considerably improved as the amount of NC increased.The results of the cellular assays exhibited increased proliferation,viability,and adhesion of MG-63 cells due to the addition of NHA and NC to the scaffolds.Finally,according to the in vitro results,it can be concluded that 3D-printed samples with higher amounts of NC can be regarded as a suitable scaffold for expediting the regeneration process of bone defects.展开更多
The bamboo powder/polycaprolactone composites (BPPC) were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the rheological properties of BPPC. The morphological behavior ...The bamboo powder/polycaprolactone composites (BPPC) were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the rheological properties of BPPC. The morphological behavior and mechanical properties of BPPC were also studied. Results showed that the optimum recipe for composite materials is composed of 70% of polycaprolactone, 30% of bamboo powder according to volume, 1.6 % of aluminate coupling agent, 1.2% of stearic acid, and 2% of paraffin to bamboo powder according to mass ratio. The optimum processing condition parameters were determined as the rotational speed at 50 r·min-1 and the temperature at 100oC for BPPC. The BPPC (containing 30 copies bamboo powder) possessed eminent interfacial compatibility and mechanical properties of BPPC.展开更多
Objective: To investigate the cytotoxicity and cytocompatibility of chitin fiber reinforced polycaprolactone composite in vitro in order to provide useful scientific basis for clinical application. Methods: Cell morph...Objective: To investigate the cytotoxicity and cytocompatibility of chitin fiber reinforced polycaprolactone composite in vitro in order to provide useful scientific basis for clinical application. Methods: Cell morphology observation, MTT and DNA assay were used to evaluate the influence of the composite on the morphology, growth and proliferation of cultured L-929 cells. Results: The composite did not impair the morphology of cultured cells in vitro. MTT and DNA assay demonstrated that the growth and proliferation of the cultured cells were not significantly inhibited by the composite. Conclusion : The composites have fine cytocompatibility and are safe for clinical use of reconstruction of chest wall defects.展开更多
Titanium and its alloys are commonly used as dental and bone implant materials.Biomimetic coating of titanium surfaces could improve their osteoinductive properties.In this work,we have developed a novel osteogenic co...Titanium and its alloys are commonly used as dental and bone implant materials.Biomimetic coating of titanium surfaces could improve their osteoinductive properties.In this work,we have developed a novel osteogenic composite nanocoating for titanium surfaces,which provides a natural environment for facilitating adhesion,proliferation,and osteogenic differentiation of bone marrow mesenchymal stem cells(MSCs).Electrospinning was used to produce composite nanofiber coatings based on polycaprolactone(PCL),nano-hydroxyapatite(nHAp)and strontium ranelate(SrRan).Thus,four types of coatings,i.e.,PCL,PCL/nHAp,PCL/SrRan,and PCL/nHAp/SrRan,were applied on titanium surfaces.To assess chemical,morphological and biological properties of the developed coatings,EDS,FTIR,XRD,XRF,SEM,AFM,in-vitro cytotoxicity and in-vitro hemocompatibility analyses were performed.Our findings have revealed that the composite nanocoatings were both cytocompatible and hemocompatible;thus PCL/HAp/SrRan composite nanofiber coating led to the highest cell viability.Osteogenic culture of MSCs on the nanocoatings led to the osteogenic differentiation of stem cells,confirmed by alkaline phosphatase activity and mineralization measurements.The findings support the notion that the proposed composite nanocoatings have the potential to promote new bone formation and enhance bone-implant integration.展开更多
This study investigated the characteristics of wood fiber/polycaprolactone composite after an artificial accelerated thermo-oxidative aging treatment.The effect of time,temperature and humidity during the treatment on...This study investigated the characteristics of wood fiber/polycaprolactone composite after an artificial accelerated thermo-oxidative aging treatment.The effect of time,temperature and humidity during the treatment on their mechanical,chemical and morphology properties were evaluated.The composite was prepared from melted wood fibers and modified polycaprolactone by a molding process.A temperature and humidity controllable test chamber was used for the thermo-oxidative aging of the composite.The thermo-oxidative aging caused surface of the composite to be much more rougher and even a few cracks and holes appeared on it.According to the spectra of Fourier Transform Infrared(FTIR)and Gel Permeation Chromatography(GPC),C=O in the molecular chain of polycaprolactone was hydrolyzed and C–O was broken after the aging treatment,which resulted in a reduction in average molecular weight of the composite.Moreover,results showed that the mechanical strength decreased a lot with the increase in time,temperature and humidity,and the effect of temperature and humidity was more significant compared with that of time.Controlling the temperature and humidity during thermo-oxidative aging treatment could accelerate the aging of composite,which provided a quick and effective method for evaluating the aging resistance of the composite.展开更多
Ultrafine polycaprolactone(PCL)fibers containing watersoluble drug tetracycline hydrochloride(Tet)were prepared by emulsion electrospinning.Sorbitan monooleate(Span80)was added as an essential additive to form stable ...Ultrafine polycaprolactone(PCL)fibers containing watersoluble drug tetracycline hydrochloride(Tet)were prepared by emulsion electrospinning.Sorbitan monooleate(Span80)was added as an essential additive to form stable water/oil emulsions and fabricate fibers with core-sheath structure.Different concentrations of Span80(0-40 g/L)were used to investigate the stability of emulsion and size of dispersed droplets.The scanning electron microscope(SEM)images indicated that the morphology of the fibers with Span80 were beaded-free with diameters of 200-400 nm,and Span80 enhanced the spinnability of electrospinning solution.The laser scanning confocal microscope(LSCM)images indicated that Tet was well encapsulated into the core region of the PCL fibers.The transmission electron microscope(TEM)image showed the formation of core-sheath structure.The loading efficiency(LE)and entrapment efficiency(EE)of Tet were calculated and release profiles in artificial saliva buffer solution(pH=6.8)were also analyzed.The results revealed that LE and EE of fibers with Span80decreased with the increase of its concentration.Fibers with coresheath structure had a longer effective release lifetime than without Span80.The increase of Span80 resulted in higher hydrophilicity of fibers and faster release rate of Tet.展开更多
Nitrate-nitrogen（NO_3^--N） always accumulates in commercial recirculating aquaculture systems（RASs） with aerobic nitrification units. The ability to reduce NO_3^--N consistently and confidently could help RASs to ...Nitrate-nitrogen（NO_3^--N） always accumulates in commercial recirculating aquaculture systems（RASs） with aerobic nitrification units. The ability to reduce NO_3^--N consistently and confidently could help RASs to become more sustainable. The rich dissolved oxygen（DO）content and sensitive organisms stocked in RASs increase the difficulty of denitrifying technology. A denitrifying process using biologically degradable polymers as an organic carbon source and biofilm carrier was proposed because of its space-efficient nature and strong ability to remove NO_3^--N from RASs. The effect of dissolved oxygen（DO） levels on heterotrophic denitrification in fixed-film reactors filled with polycaprolactone（PCL） was explored in the current experiment. DO conditions in the influent of the denitrifying reactors were set up as follows： the anoxic treatment group（Group A, average DO concentration of 0.28 ± 0.05 mg/L）, the low-oxygen treatment DO group（Group B, average DO concentration of 2.50 ± 0.24 mg/L） and the aerated treatment group（Group C, average DO concentration of 5.63 ± 0.57 mg/L）. Feeding with 200 mg/L of NO_3^--N, the NO_3^--N removal rates were 1.53, 1.60 and 1.42 kg/m3PCL/day in Groups A, B and C, respectively. No significant difference in NO_3^--N removal rates was observed among the three treatments. It was concluded that the inhibitory effects of DO concentrations lower than 6 mg/L on heterotrophic denitrification in the fixed-film reactors filled with PCL can be mitigated.展开更多
Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly wat...Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly water soluble compound) loaded polycaprolactone(nanoDDA) was synthesized using the solvent evaporation technique. Nano-DDA was characterized by scanning electron microscopy(SEM) and dynamic light scattering(DLS) studies. Fourier Transform InfraRed Spectroscopy(FTIR) was used to investigate the structural interaction between the drug and the polymer. Functional characterization of the formulation was determined using drug content, cellular uptake and in vitro drug release. 2-deoxy-D-[1-~3H] glucose uptake assay was carried out to assess the antidiabetic potential of nano-DDA in L6 myotubes.The nano-DDA displayed spherical shape with a smooth surface(252.898 nm diameter), zeta potential, encapsulation and loading efficiencies of -38.9 mV, 91.98 ± 0.13% and 15.09 ± 0.18% respectively. No structural alteration between the drug and the polymer was evidenced(FTIR analysis). Confocal microscopy studies with rhodamine 123 loaded polycaprolactone nanoparticles(Rh123-PCL NPs) revealed the internalization of Rh123-PCL NPs in a time dependent manner in L6 myoblasts. A dose dependent increase in glucose uptake was observed for nano-DDA with a maximal uptake of 108.54 ± 1.42% at 100 nM on L6 myotubes, thereby proving its anti-diabetic efficacy. A biphasic pattern of in vitro drug release demonstrated an initial burst release at 24 h followed by a sustained release for up to 11 days. To conclude,our results revealed that nano-DDA formulation can be a potent candidate for antidiabetic drug delivery.展开更多
The bamboo powder/polycaprolactone composites （BPPC） were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the theological properties of BPPC. The morphological behavio...The bamboo powder/polycaprolactone composites （BPPC） were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the theological properties of BPPC. The morphological behavior and mechanical properties of BPPC were also studied. Results showed that the optimum recipe for composite materials is composed of 70% of polycaprolactone, 30% of bamboo powder according to volume, 1.6 % of aluminate coupling agent, 1.2% of stearic acid, and 2% of paraffin to bamboo powder according to mass ratio The optimum processing condition parameters were determined as the rotational speed at 50 r-min^-1 and the temperature at 100℃ for BPPC. The BPPC （containing 30 copies bamboo powder） possessed eminent interfacial compatibility and mechanical properties of BPPC.展开更多
In this study,nano-biocomposites of polycaprolactone(PCL)as the matrix and different amounts of nanofluorapatite(nFA)(0,10,20 and 30 wt.%)as the reinforcement were prepared for possible scaffold fabrication using the ...In this study,nano-biocomposites of polycaprolactone(PCL)as the matrix and different amounts of nanofluorapatite(nFA)(0,10,20 and 30 wt.%)as the reinforcement were prepared for possible scaffold fabrication using the fused filament fabrication(FFF)3D printer.Field Emission Scanning Electron Microscopy(FE-SEM)and Energy Dispersive Spectroscopy(EDS)showed that nFA particles were well distributed in the PCL matrix.X-ray diffraction analysis(XRD)and Fourier Transform Infrared Spectroscopy(FTIR)depicted no chemical interaction between the elements of the composite.Differential Scanning Calorimetric(DSC)analysis was then used to assess the thermal properties of the composites,suggesting that this could be due to the amorphous phase formation of the intermolecular hydrogen bonds between PCL and nFA,resulting in the suppression of PCL crystallization.The results of mechanical characterization also showed that the addition of nFA up to 20 wt.%to the PCL increased the tensile and yield strength,as well as reducing the elongation at both yield and failure points and increasing the Young modulus.The best mechanical properties were obtained for the PCL/20nFA composite.Tensile strength and Young modulus were increased by 30%and 179%,respectively;meanwhile,elongation of PCL/20nFA was decreased by 70%,as compared to the naked PCL.These changes could be attributed to the better distribution of the nFA filler in the PCL matrix.According to the obtained results,PCL/20nFA could be regarded as a good composite in terms of the mechanical properties for the regeneration of the bone tissue.展开更多
Combinations of metal and lanthanide oxides have been done through casted films for potential medical applications. In this regard, samarium(Ⅲ) oxide/chromium(Ⅲ) oxide/graphene oxide(GO)/polycaprolactone(PCL) based ...Combinations of metal and lanthanide oxides have been done through casted films for potential medical applications. In this regard, samarium(Ⅲ) oxide/chromium(Ⅲ) oxide/graphene oxide(GO)/polycaprolactone(PCL) based films nano-composites(NCs) were fabricated, pointing their utilization as a biological scaffold for wound dressing purposes. Also, samarium(Ⅲ) oxide and chromium(Ⅲ) oxide have been merged as promising optical constituents due to their unique optical behavior. The structural and compositional examination of the studied NCs was executed by X-ray diffraction(XRD), Raman, and field emission scanning electron microscopy(FESEM). The Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL NC exhibits a surface with a lower roughness degree owing to the presence of GO. Cr_(2)O_(3)shows size reduction upon GO insertion to reach 1.2 μm as the average grain size, whilst Sm_(2)O_(3)records an average grain size of less than 1 μm. As well, the polymeric nano-compositions exhibit variation in contact angle values that hit 29.76°± 3.52°for Sm_(2)O_(3)/PCL, and 48.62°± 1.37°for Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL as the second lowest contact angle. The optical behavior contributes to absorption edge relocation along the x-axis from 1.7 eV for pure PCL, to 2.65 eV for Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL. Regarding biological responses, the cell exposed to 2.5 μg/m L of Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL shows cell viability of 119.31%, while 5 μg/m L hits 99.6%. Additionally, the resulting cell attachment micrographs show layers of fibroblast tissue, besides the proliferation and growth of cultivated cells. Thus, the Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL scaffold provides 3D proliferation of fibroblast cells endorsing the wound healing process.展开更多
Composite hernia meshes designed in this paper consist of polypropylene( PP) knitted meshes and polycaprolactone( PCL)nanofiber membranes,which are produced by electro-spinning the solution composed of PCL as a solute...Composite hernia meshes designed in this paper consist of polypropylene( PP) knitted meshes and polycaprolactone( PCL)nanofiber membranes,which are produced by electro-spinning the solution composed of PCL as a solute and the mixture of dimethylformamide( DMF) and dichloromethane( DCM) as a solvent. The morphology and diameter of nanofibers in the membrane are well performed when the 15% PCL solution is electrospun under the condition of 18 k V,15 cm,0. 7 m L/h. The poresize of the membranes is less than 10 μm, where such kinds of arrangement are extremely compact to prevent the cells from growing in. The mechanical properties of the membrane with better arrangement state can reach 68. 8 c N/mm^2. The cytotoxicity test of the composite mesh demonstrates the nontoxicity of the materials.However,the bonding fastness between the membrane and the PP mesh is extremely unsubstantial. The better ways to bond PP mesh with PCL membranes should be discussed in the future.展开更多
At 225℃. caprolactone has been polymerized in the presence of succinic acid under dry nitrogen atmosphere. Characterizations of the polymer through IR and molecular weight measurements by 1H-NMR and end group titrati...At 225℃. caprolactone has been polymerized in the presence of succinic acid under dry nitrogen atmosphere. Characterizations of the polymer through IR and molecular weight measurements by 1H-NMR and end group titration have shown that the polycaprolactone obtained is of two carboxyl end groups. The molecular weight of it increases with decreasing of the acid content in the reaction mixture under the same polymerization conditions. With a certain ratio of acid to caprolactone. the maximum of molecular weight of the polymer will be reached at the reaction time of 3h.展开更多
In this study, nanostructured microparticles was developed with polycaprolactone (PCL), poly(vinyl alcohol) (PVAL) and nanoparticles of the commercial sodium clay NT-25®by using the spray drying technique. The...In this study, nanostructured microparticles was developed with polycaprolactone (PCL), poly(vinyl alcohol) (PVAL) and nanoparticles of the commercial sodium clay NT-25®by using the spray drying technique. The systems obtained were characterized by Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic Laser Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). The NMR <sup>13</sup>C and FTIR techniques showed that both polymers were present in the microparticles and the DSC analysis revealed a small variation in the glass transition temperature of the PCL. The XRD and SEM analyses showed that the microparticles produced were amorphous and had a concave morphology. The NT-25 nanoload reduced the microparticles’ size due to the multiple interactions formed in the hybrid nanocomposite material. Therefore, it was possible to develop microparticles by using biodegradable and biocompatible polymers, with different polarities, allowing the incorporation of hydrophilic and hydrophobic materials and enabling the inclusion of otherwise incompatible materials in the same system.展开更多
The drug release behavior of degradable polymer--polycaprolactone-poly (ethyleneglycol)block copolymer(PCE) in vitro was investigated by using 5-Fluoro-uracil (5-Fu) asa model drug under a condition of pH 7. 4 at 37C....The drug release behavior of degradable polymer--polycaprolactone-poly (ethyleneglycol)block copolymer(PCE) in vitro was investigated by using 5-Fluoro-uracil (5-Fu) asa model drug under a condition of pH 7. 4 at 37C. It is found that the release rate of 5-Fufrom PCE increased with increasing polyether content of the copolymer. The results showthat the increasing polyether content of the copolymer caused increasing hydrophilicity anddecreasing crystallinity of the PCE copolymer. Thus, the drug release behavior and thedegradable property of the PCE can be controlled by adjusting the composition of thecopolymer.展开更多
Engineered cardiac constructs(ECC)aid in the progression of regenerative medicine,disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects ...Engineered cardiac constructs(ECC)aid in the progression of regenerative medicine,disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects of drugs.In this research,polycaprolactone/gold nanoparticles(PCL/GNPs)three-dimensional(3D)composite scaffolds were manufactured by 3D printing using the fused deposition modeling(FDM)method and then coated with gelatin/spironolactone(GEL/SPL).Scanning electron microscopy(SEM)and Fourier transform-infrared spectroscopy(FTIR–ATR)were applied to characterize the samples.Furthermore,drug release,biodegradation,behavior of the myoblasts(H9C2)cell line,and cytotoxicity of the 3D scaffolds were evaluated.The microstructural observation of the scaffolds reported interconnected pores with 150–300µm in diameter.The 3D scaffolds were degraded significantly after 28 days of immersion in stimulated body fluid(SBF),with the maximum rate of GEL-coated 3D scaffolds.SPL release from cross-linked GEL coating demonstrated the excess of drug release over time,and according to the control release systems,the drug delivery systems(DDS)went into balance after the 14th day.In addition,cell culture study showed that with the addition of GNPs,the proliferation of(H9C2)was enhanced,and with GEL/SPL coating the cell attachment and viability were improved significantly.These findings suggested that PCL/GNPs 3D scaffolds coated with GEL/SPL can be an appropriate choice for myocardial tissue engineering.展开更多
Biodegradable magnesium(Mg)and its alloys exhibit excellent biocompatibility and mechanical compatibility,demonstrating tremendous potential for applications in orthopedics.However,the rapid degradation rate has limit...Biodegradable magnesium(Mg)and its alloys exhibit excellent biocompatibility and mechanical compatibility,demonstrating tremendous potential for applications in orthopedics.However,the rapid degradation rate has limited their clinical application.Polycaprolactone(PCL)is commonly employed as a polymer coating to impede the rapid degradation of Mg.Unfortunately,its long-term anti-corrosion capability and bioactivity are inadequate.To address these issues,polydopamine(PDA)-modified zeolitic imidazolate framework-8(PZIF-8)bioactive nanoparticles are fabricated and incorporated into the PCL coating.The PZIF-8 particles,featuring catechol motifs,can enhance the compactness of the PCL coating,reduce its defects,and possess biomineralization ability,thereby effectively improving its anti-corrosive and bioactive properties.Moreover,the active substances released from the degradation of the PZIF-8 particles such as Zn^(2+)and PDA are beneficial for osteogenesis.The corrosion tests indicate that the corrosion current density of PCL-treated sample decreases by more than one order of magnitude and the amount of H_(2)released decreases from 0.23±0.12 to 0.08±0.08 ml cm^(-2)after doping with the PZIF-8.Furthermore,the improved corrosion resistance and released PDA and Zn^(2+)from the coating can promote osteogenic differentiation by up-regulating the expression of alkaline phosphatase activity,related osteogenic genes,and proteins.In addition,in vivo implantation experiments in rabbit femur defects further offer strong evidence that the doping of PZIF-8 nanoparticles accelerates bone reconstruction of the PCL coating.In summary,this work implies a new strategy to fabricate a PCL-based coating on Mg-based implants by introducing the PZIF-8 particles for orthopedic applications.展开更多
Electrospun nanofibers combined with a wide range of functional additives can be used for a various tissue engineering applications due to their desired biomimetic and physicochemical properties.Therefore,the present ...Electrospun nanofibers combined with a wide range of functional additives can be used for a various tissue engineering applications due to their desired biomimetic and physicochemical properties.Therefore,the present study was conducted to obtain a highly efficient nanocomposite electrospun scaffold with appropriate physicochemical performance and biological properties based on Polycaprolactone/Polyurethane(PCL/PU)mixed with gold nanoparticles(GNPs)and soybean oil(SO).In the present study,the desired nanofibers were fabricated by electrospinning PCL/PU mixed solution with GNPs and SO.The nanocomposite electrospun PU/PCL/SO/GNP nanofibers were characterized in terms of chemical composition by attenuated total reflectance-Fourier transform infrared spectroscopy(ATR-FTIR),morphological structure by field-emission scanning electron microscopy(FE-SEM),and mechanical and biological properties.The surface topography and wettability were determined by atomic force microscopy(AFM)and water contact angle measurements,respectively.It was found that the presence of GNPs along with SO in the structure of PCL/PU nanofiber created a smoother surface in terms of surface roughness and also a more homogeneous fibrous structure.In addition,it was observed that both SO and GNPs caused an increase in the electrical conductivity of the fibrous mats.In the biocompatibility evaluations by measuring cell viability and cell adherence to the scaffold's surfaces,it was found that adding of SO and GNPs supports fibroblasts.Taken together,the fabricated nanocomposite fibrous scaffolds can be a potential candidate for various tissue engineering purposes.展开更多
To tackle the challenge of producing highly filled polymer composites using the traditional injection molding technique,which is characterized by the fairly high melt viscosity that makes mold filling difficult,the au...To tackle the challenge of producing highly filled polymer composites using the traditional injection molding technique,which is characterized by the fairly high melt viscosity that makes mold filling difficult,the authors propose a solution based on dynamic covalent chemistry.As demonstrated by the proof-of-concept experiments,the 4-arm starshaped polycaprolactone(PCL)oligomers and microcrystalline cel-lulose(MCC)are crosslinked by the reversible Diels-Alder(DA)bonds.The flowability of the compounds greatly decreases due to the dissociation of the intercomponent DA bonds at the retro-reaction tempera-ture,and the networked architecture is reconstructed during cooling as a result of the forward DA reaction.Consequently,the high-loading MCC fillers are well distributed in the matrix and covalently bonded to the nearby PCL,forming a striking contrast to the control in which linear PCL acts as the matrix.The DA bonds crosslinked biodegradable PCL composites exhibit decent mechanical strength(20.7 MPa)even at the MCC fraction of 65 wt%,which is superior to those(5-12.2 MPa)of the highly filled PCL composites(with filler contents of 50-63.8 wt%)reported so far.The proposed approach has sufficient expansibility for the fabrication of the highly filled polymer composites constructed by other types of matrix and fillers.展开更多
文摘The field of bone tissue engineering has experienced an increase in prevalence due to the inherent challenge of the natural regeneration of significant bone deformities.This investigation focused on the preparation of Three-Dimensional(3D)-printed Polycaprolactone(PCL)scaffolds with varying proportions of Nanohydroxyapatite(NHA)and Nanoclay(NC),and their physiochemical and biological properties were assessed.The mechanical properties of PCL are satisfactory;however,its hydrophobic nature and long-term degradation hinder its use in scaffold fabrication.NHA and NC have been employed to improve the hydrophilic characteristics,mechanical strength,adhesive properties,biocompatibility,biodegradability,and osteoconductive behavior of PCL.The morphology results demonstrated 3D-printed structures with interconnected rectangular macropores and proper nanoparticle distribution.The sample containing 70 wt%NC showed the highest porosity(65.98±2.54%),leading to an increased degradation rate.The compressive strength ranged from 10.65±1.90 to 84.93±9.93 MPa,which is directly proportional to the compressive strength of cancellous bone(2–12 MPa).The wettability,water uptake,and biodegradability of PCL scaffolds considerably improved as the amount of NC increased.The results of the cellular assays exhibited increased proliferation,viability,and adhesion of MG-63 cells due to the addition of NHA and NC to the scaffolds.Finally,according to the in vitro results,it can be concluded that 3D-printed samples with higher amounts of NC can be regarded as a suitable scaffold for expediting the regeneration process of bone defects.
基金funded by Natural Science Founda-tion of Fujian Province (No. 2008J0227)Science and TechnologyOffice of Fujian Province (No. 2007F5030)
文摘The bamboo powder/polycaprolactone composites (BPPC) were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the rheological properties of BPPC. The morphological behavior and mechanical properties of BPPC were also studied. Results showed that the optimum recipe for composite materials is composed of 70% of polycaprolactone, 30% of bamboo powder according to volume, 1.6 % of aluminate coupling agent, 1.2% of stearic acid, and 2% of paraffin to bamboo powder according to mass ratio. The optimum processing condition parameters were determined as the rotational speed at 50 r·min-1 and the temperature at 100oC for BPPC. The BPPC (containing 30 copies bamboo powder) possessed eminent interfacial compatibility and mechanical properties of BPPC.
基金Supported by the Sci & Tech Development Foundation of Shang-hai (No. 024419076)
文摘Objective: To investigate the cytotoxicity and cytocompatibility of chitin fiber reinforced polycaprolactone composite in vitro in order to provide useful scientific basis for clinical application. Methods: Cell morphology observation, MTT and DNA assay were used to evaluate the influence of the composite on the morphology, growth and proliferation of cultured L-929 cells. Results: The composite did not impair the morphology of cultured cells in vitro. MTT and DNA assay demonstrated that the growth and proliferation of the cultured cells were not significantly inhibited by the composite. Conclusion : The composites have fine cytocompatibility and are safe for clinical use of reconstruction of chest wall defects.
文摘Titanium and its alloys are commonly used as dental and bone implant materials.Biomimetic coating of titanium surfaces could improve their osteoinductive properties.In this work,we have developed a novel osteogenic composite nanocoating for titanium surfaces,which provides a natural environment for facilitating adhesion,proliferation,and osteogenic differentiation of bone marrow mesenchymal stem cells(MSCs).Electrospinning was used to produce composite nanofiber coatings based on polycaprolactone(PCL),nano-hydroxyapatite(nHAp)and strontium ranelate(SrRan).Thus,four types of coatings,i.e.,PCL,PCL/nHAp,PCL/SrRan,and PCL/nHAp/SrRan,were applied on titanium surfaces.To assess chemical,morphological and biological properties of the developed coatings,EDS,FTIR,XRD,XRF,SEM,AFM,in-vitro cytotoxicity and in-vitro hemocompatibility analyses were performed.Our findings have revealed that the composite nanocoatings were both cytocompatible and hemocompatible;thus PCL/HAp/SrRan composite nanofiber coating led to the highest cell viability.Osteogenic culture of MSCs on the nanocoatings led to the osteogenic differentiation of stem cells,confirmed by alkaline phosphatase activity and mineralization measurements.The findings support the notion that the proposed composite nanocoatings have the potential to promote new bone formation and enhance bone-implant integration.
基金The work was supported by National Key R&D Plan Project(2017YFD0601200)Hunan Key R&D Plan Project(2017SK2334)of College of Materials Science and Engineering,Central South University of Forestry and Technology.
文摘This study investigated the characteristics of wood fiber/polycaprolactone composite after an artificial accelerated thermo-oxidative aging treatment.The effect of time,temperature and humidity during the treatment on their mechanical,chemical and morphology properties were evaluated.The composite was prepared from melted wood fibers and modified polycaprolactone by a molding process.A temperature and humidity controllable test chamber was used for the thermo-oxidative aging of the composite.The thermo-oxidative aging caused surface of the composite to be much more rougher and even a few cracks and holes appeared on it.According to the spectra of Fourier Transform Infrared(FTIR)and Gel Permeation Chromatography(GPC),C=O in the molecular chain of polycaprolactone was hydrolyzed and C–O was broken after the aging treatment,which resulted in a reduction in average molecular weight of the composite.Moreover,results showed that the mechanical strength decreased a lot with the increase in time,temperature and humidity,and the effect of temperature and humidity was more significant compared with that of time.Controlling the temperature and humidity during thermo-oxidative aging treatment could accelerate the aging of composite,which provided a quick and effective method for evaluating the aging resistance of the composite.
基金“111 Project” Biomedical Textile Materials Science and Technology,China(No.B07024)
文摘Ultrafine polycaprolactone(PCL)fibers containing watersoluble drug tetracycline hydrochloride(Tet)were prepared by emulsion electrospinning.Sorbitan monooleate(Span80)was added as an essential additive to form stable water/oil emulsions and fabricate fibers with core-sheath structure.Different concentrations of Span80(0-40 g/L)were used to investigate the stability of emulsion and size of dispersed droplets.The scanning electron microscope(SEM)images indicated that the morphology of the fibers with Span80 were beaded-free with diameters of 200-400 nm,and Span80 enhanced the spinnability of electrospinning solution.The laser scanning confocal microscope(LSCM)images indicated that Tet was well encapsulated into the core region of the PCL fibers.The transmission electron microscope(TEM)image showed the formation of core-sheath structure.The loading efficiency(LE)and entrapment efficiency(EE)of Tet were calculated and release profiles in artificial saliva buffer solution(pH=6.8)were also analyzed.The results revealed that LE and EE of fibers with Span80decreased with the increase of its concentration.Fibers with coresheath structure had a longer effective release lifetime than without Span80.The increase of Span80 resulted in higher hydrophilicity of fibers and faster release rate of Tet.
基金supported by the Shanghai Science and Technology Commission Project (No.14320501900)the Shanghai Engineering and Technology Center for Promoting Ability Project (No.13DZ2280500)
文摘Nitrate-nitrogen（NO_3^--N） always accumulates in commercial recirculating aquaculture systems（RASs） with aerobic nitrification units. The ability to reduce NO_3^--N consistently and confidently could help RASs to become more sustainable. The rich dissolved oxygen（DO）content and sensitive organisms stocked in RASs increase the difficulty of denitrifying technology. A denitrifying process using biologically degradable polymers as an organic carbon source and biofilm carrier was proposed because of its space-efficient nature and strong ability to remove NO_3^--N from RASs. The effect of dissolved oxygen（DO） levels on heterotrophic denitrification in fixed-film reactors filled with polycaprolactone（PCL） was explored in the current experiment. DO conditions in the influent of the denitrifying reactors were set up as follows： the anoxic treatment group（Group A, average DO concentration of 0.28 ± 0.05 mg/L）, the low-oxygen treatment DO group（Group B, average DO concentration of 2.50 ± 0.24 mg/L） and the aerated treatment group（Group C, average DO concentration of 5.63 ± 0.57 mg/L）. Feeding with 200 mg/L of NO_3^--N, the NO_3^--N removal rates were 1.53, 1.60 and 1.42 kg/m3PCL/day in Groups A, B and C, respectively. No significant difference in NO_3^--N removal rates was observed among the three treatments. It was concluded that the inhibitory effects of DO concentrations lower than 6 mg/L on heterotrophic denitrification in the fixed-film reactors filled with PCL can be mitigated.
文摘Biodegradable polymer based novel drug delivery systems brought a considerable attention in enhancing the therapeutic efficacy and bioavailability of various drugs. 14-deoxy 11, 12-didehydro andrographolide(poorly water soluble compound) loaded polycaprolactone(nanoDDA) was synthesized using the solvent evaporation technique. Nano-DDA was characterized by scanning electron microscopy(SEM) and dynamic light scattering(DLS) studies. Fourier Transform InfraRed Spectroscopy(FTIR) was used to investigate the structural interaction between the drug and the polymer. Functional characterization of the formulation was determined using drug content, cellular uptake and in vitro drug release. 2-deoxy-D-[1-~3H] glucose uptake assay was carried out to assess the antidiabetic potential of nano-DDA in L6 myotubes.The nano-DDA displayed spherical shape with a smooth surface(252.898 nm diameter), zeta potential, encapsulation and loading efficiencies of -38.9 mV, 91.98 ± 0.13% and 15.09 ± 0.18% respectively. No structural alteration between the drug and the polymer was evidenced(FTIR analysis). Confocal microscopy studies with rhodamine 123 loaded polycaprolactone nanoparticles(Rh123-PCL NPs) revealed the internalization of Rh123-PCL NPs in a time dependent manner in L6 myoblasts. A dose dependent increase in glucose uptake was observed for nano-DDA with a maximal uptake of 108.54 ± 1.42% at 100 nM on L6 myotubes, thereby proving its anti-diabetic efficacy. A biphasic pattern of in vitro drug release demonstrated an initial burst release at 24 h followed by a sustained release for up to 11 days. To conclude,our results revealed that nano-DDA formulation can be a potent candidate for antidiabetic drug delivery.
基金This work was funded by Natural Science Foundation of Fujian Province （No. 2008J0227） and Science and Technology Office of Fujian Province （No. 2007F5030）,
文摘The bamboo powder/polycaprolactone composites （BPPC） were prepared by torque-rheometer to investigate the effects of recipes and processing conditions on the theological properties of BPPC. The morphological behavior and mechanical properties of BPPC were also studied. Results showed that the optimum recipe for composite materials is composed of 70% of polycaprolactone, 30% of bamboo powder according to volume, 1.6 % of aluminate coupling agent, 1.2% of stearic acid, and 2% of paraffin to bamboo powder according to mass ratio The optimum processing condition parameters were determined as the rotational speed at 50 r-min^-1 and the temperature at 100℃ for BPPC. The BPPC （containing 30 copies bamboo powder） possessed eminent interfacial compatibility and mechanical properties of BPPC.
文摘In this study,nano-biocomposites of polycaprolactone(PCL)as the matrix and different amounts of nanofluorapatite(nFA)(0,10,20 and 30 wt.%)as the reinforcement were prepared for possible scaffold fabrication using the fused filament fabrication(FFF)3D printer.Field Emission Scanning Electron Microscopy(FE-SEM)and Energy Dispersive Spectroscopy(EDS)showed that nFA particles were well distributed in the PCL matrix.X-ray diffraction analysis(XRD)and Fourier Transform Infrared Spectroscopy(FTIR)depicted no chemical interaction between the elements of the composite.Differential Scanning Calorimetric(DSC)analysis was then used to assess the thermal properties of the composites,suggesting that this could be due to the amorphous phase formation of the intermolecular hydrogen bonds between PCL and nFA,resulting in the suppression of PCL crystallization.The results of mechanical characterization also showed that the addition of nFA up to 20 wt.%to the PCL increased the tensile and yield strength,as well as reducing the elongation at both yield and failure points and increasing the Young modulus.The best mechanical properties were obtained for the PCL/20nFA composite.Tensile strength and Young modulus were increased by 30%and 179%,respectively;meanwhile,elongation of PCL/20nFA was decreased by 70%,as compared to the naked PCL.These changes could be attributed to the better distribution of the nFA filler in the PCL matrix.According to the obtained results,PCL/20nFA could be regarded as a good composite in terms of the mechanical properties for the regeneration of the bone tissue.
基金funded by the Scientific Research Deanship at University of Ha'il,Saudi Arabia through project number RG-21169。
文摘Combinations of metal and lanthanide oxides have been done through casted films for potential medical applications. In this regard, samarium(Ⅲ) oxide/chromium(Ⅲ) oxide/graphene oxide(GO)/polycaprolactone(PCL) based films nano-composites(NCs) were fabricated, pointing their utilization as a biological scaffold for wound dressing purposes. Also, samarium(Ⅲ) oxide and chromium(Ⅲ) oxide have been merged as promising optical constituents due to their unique optical behavior. The structural and compositional examination of the studied NCs was executed by X-ray diffraction(XRD), Raman, and field emission scanning electron microscopy(FESEM). The Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL NC exhibits a surface with a lower roughness degree owing to the presence of GO. Cr_(2)O_(3)shows size reduction upon GO insertion to reach 1.2 μm as the average grain size, whilst Sm_(2)O_(3)records an average grain size of less than 1 μm. As well, the polymeric nano-compositions exhibit variation in contact angle values that hit 29.76°± 3.52°for Sm_(2)O_(3)/PCL, and 48.62°± 1.37°for Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL as the second lowest contact angle. The optical behavior contributes to absorption edge relocation along the x-axis from 1.7 eV for pure PCL, to 2.65 eV for Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL. Regarding biological responses, the cell exposed to 2.5 μg/m L of Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL shows cell viability of 119.31%, while 5 μg/m L hits 99.6%. Additionally, the resulting cell attachment micrographs show layers of fibroblast tissue, besides the proliferation and growth of cultivated cells. Thus, the Sm_(2)O_(3)/Cr_(2)O_(3)/GO/PCL scaffold provides 3D proliferation of fibroblast cells endorsing the wound healing process.
基金Biomedical Textile Materials Science and Technology(111 Project),China(No.B07024)
文摘Composite hernia meshes designed in this paper consist of polypropylene( PP) knitted meshes and polycaprolactone( PCL)nanofiber membranes,which are produced by electro-spinning the solution composed of PCL as a solute and the mixture of dimethylformamide( DMF) and dichloromethane( DCM) as a solvent. The morphology and diameter of nanofibers in the membrane are well performed when the 15% PCL solution is electrospun under the condition of 18 k V,15 cm,0. 7 m L/h. The poresize of the membranes is less than 10 μm, where such kinds of arrangement are extremely compact to prevent the cells from growing in. The mechanical properties of the membrane with better arrangement state can reach 68. 8 c N/mm^2. The cytotoxicity test of the composite mesh demonstrates the nontoxicity of the materials.However,the bonding fastness between the membrane and the PP mesh is extremely unsubstantial. The better ways to bond PP mesh with PCL membranes should be discussed in the future.
文摘At 225℃. caprolactone has been polymerized in the presence of succinic acid under dry nitrogen atmosphere. Characterizations of the polymer through IR and molecular weight measurements by 1H-NMR and end group titration have shown that the polycaprolactone obtained is of two carboxyl end groups. The molecular weight of it increases with decreasing of the acid content in the reaction mixture under the same polymerization conditions. With a certain ratio of acid to caprolactone. the maximum of molecular weight of the polymer will be reached at the reaction time of 3h.
文摘In this study, nanostructured microparticles was developed with polycaprolactone (PCL), poly(vinyl alcohol) (PVAL) and nanoparticles of the commercial sodium clay NT-25®by using the spray drying technique. The systems obtained were characterized by Nuclear Magnetic Resonance (NMR), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Dynamic Laser Light Scattering (DLS) and Differential Scanning Calorimetry (DSC). The NMR <sup>13</sup>C and FTIR techniques showed that both polymers were present in the microparticles and the DSC analysis revealed a small variation in the glass transition temperature of the PCL. The XRD and SEM analyses showed that the microparticles produced were amorphous and had a concave morphology. The NT-25 nanoload reduced the microparticles’ size due to the multiple interactions formed in the hybrid nanocomposite material. Therefore, it was possible to develop microparticles by using biodegradable and biocompatible polymers, with different polarities, allowing the incorporation of hydrophilic and hydrophobic materials and enabling the inclusion of otherwise incompatible materials in the same system.
文摘The drug release behavior of degradable polymer--polycaprolactone-poly (ethyleneglycol)block copolymer(PCE) in vitro was investigated by using 5-Fluoro-uracil (5-Fu) asa model drug under a condition of pH 7. 4 at 37C. It is found that the release rate of 5-Fufrom PCE increased with increasing polyether content of the copolymer. The results showthat the increasing polyether content of the copolymer caused increasing hydrophilicity anddecreasing crystallinity of the PCE copolymer. Thus, the drug release behavior and thedegradable property of the PCE can be controlled by adjusting the composition of thecopolymer.
文摘Engineered cardiac constructs(ECC)aid in the progression of regenerative medicine,disease modeling and targeted drug delivery to adjust and aim the release of remedial combination as well as decrease the side effects of drugs.In this research,polycaprolactone/gold nanoparticles(PCL/GNPs)three-dimensional(3D)composite scaffolds were manufactured by 3D printing using the fused deposition modeling(FDM)method and then coated with gelatin/spironolactone(GEL/SPL).Scanning electron microscopy(SEM)and Fourier transform-infrared spectroscopy(FTIR–ATR)were applied to characterize the samples.Furthermore,drug release,biodegradation,behavior of the myoblasts(H9C2)cell line,and cytotoxicity of the 3D scaffolds were evaluated.The microstructural observation of the scaffolds reported interconnected pores with 150–300µm in diameter.The 3D scaffolds were degraded significantly after 28 days of immersion in stimulated body fluid(SBF),with the maximum rate of GEL-coated 3D scaffolds.SPL release from cross-linked GEL coating demonstrated the excess of drug release over time,and according to the control release systems,the drug delivery systems(DDS)went into balance after the 14th day.In addition,cell culture study showed that with the addition of GNPs,the proliferation of(H9C2)was enhanced,and with GEL/SPL coating the cell attachment and viability were improved significantly.These findings suggested that PCL/GNPs 3D scaffolds coated with GEL/SPL can be an appropriate choice for myocardial tissue engineering.
基金financially supported by the Guangzhou Science and Technology Project(Nos.2021A0505030042 and 201904010060)Guangdong Basic and Applied Basic Research Foundation(No.2020B1515120078)+2 种基金National Natural Science Foundation of China(Nos.81401766 and 32101059)Natural Science Foundation of Guangdong Province(No.2022A1515010266)Shenzhen Key Laboratory of Musculoskeletal Tissue Reconstruction and Function Restoration and Shenzhen People’s Hospital(No.ZDSYS20200811143752005)。
文摘Biodegradable magnesium(Mg)and its alloys exhibit excellent biocompatibility and mechanical compatibility,demonstrating tremendous potential for applications in orthopedics.However,the rapid degradation rate has limited their clinical application.Polycaprolactone(PCL)is commonly employed as a polymer coating to impede the rapid degradation of Mg.Unfortunately,its long-term anti-corrosion capability and bioactivity are inadequate.To address these issues,polydopamine(PDA)-modified zeolitic imidazolate framework-8(PZIF-8)bioactive nanoparticles are fabricated and incorporated into the PCL coating.The PZIF-8 particles,featuring catechol motifs,can enhance the compactness of the PCL coating,reduce its defects,and possess biomineralization ability,thereby effectively improving its anti-corrosive and bioactive properties.Moreover,the active substances released from the degradation of the PZIF-8 particles such as Zn^(2+)and PDA are beneficial for osteogenesis.The corrosion tests indicate that the corrosion current density of PCL-treated sample decreases by more than one order of magnitude and the amount of H_(2)released decreases from 0.23±0.12 to 0.08±0.08 ml cm^(-2)after doping with the PZIF-8.Furthermore,the improved corrosion resistance and released PDA and Zn^(2+)from the coating can promote osteogenic differentiation by up-regulating the expression of alkaline phosphatase activity,related osteogenic genes,and proteins.In addition,in vivo implantation experiments in rabbit femur defects further offer strong evidence that the doping of PZIF-8 nanoparticles accelerates bone reconstruction of the PCL coating.In summary,this work implies a new strategy to fabricate a PCL-based coating on Mg-based implants by introducing the PZIF-8 particles for orthopedic applications.
基金funded by Department of Medical Nanotechnology,Faculty of Advanced Medical Sciences,Tabriz University of Medical Sciences (Grant NO:62379).
文摘Electrospun nanofibers combined with a wide range of functional additives can be used for a various tissue engineering applications due to their desired biomimetic and physicochemical properties.Therefore,the present study was conducted to obtain a highly efficient nanocomposite electrospun scaffold with appropriate physicochemical performance and biological properties based on Polycaprolactone/Polyurethane(PCL/PU)mixed with gold nanoparticles(GNPs)and soybean oil(SO).In the present study,the desired nanofibers were fabricated by electrospinning PCL/PU mixed solution with GNPs and SO.The nanocomposite electrospun PU/PCL/SO/GNP nanofibers were characterized in terms of chemical composition by attenuated total reflectance-Fourier transform infrared spectroscopy(ATR-FTIR),morphological structure by field-emission scanning electron microscopy(FE-SEM),and mechanical and biological properties.The surface topography and wettability were determined by atomic force microscopy(AFM)and water contact angle measurements,respectively.It was found that the presence of GNPs along with SO in the structure of PCL/PU nanofiber created a smoother surface in terms of surface roughness and also a more homogeneous fibrous structure.In addition,it was observed that both SO and GNPs caused an increase in the electrical conductivity of the fibrous mats.In the biocompatibility evaluations by measuring cell viability and cell adherence to the scaffold's surfaces,it was found that adding of SO and GNPs supports fibroblasts.Taken together,the fabricated nanocomposite fibrous scaffolds can be a potential candidate for various tissue engineering purposes.
基金the support of the National Natural Science Foundation of China(Grants:52033011,51973237,and 52173092)Natural Science Foundation of Guangdong Province(Grants:2019B1515120038,2020A1515011276,2021A1515010417)+1 种基金Science and Technology Planning Project of Guangzhou City(Grant:202201011568)Fundamental Research Funds for the Central Universities,Sun Yatsen University(Grant:23yxqntd002).
文摘To tackle the challenge of producing highly filled polymer composites using the traditional injection molding technique,which is characterized by the fairly high melt viscosity that makes mold filling difficult,the authors propose a solution based on dynamic covalent chemistry.As demonstrated by the proof-of-concept experiments,the 4-arm starshaped polycaprolactone(PCL)oligomers and microcrystalline cel-lulose(MCC)are crosslinked by the reversible Diels-Alder(DA)bonds.The flowability of the compounds greatly decreases due to the dissociation of the intercomponent DA bonds at the retro-reaction tempera-ture,and the networked architecture is reconstructed during cooling as a result of the forward DA reaction.Consequently,the high-loading MCC fillers are well distributed in the matrix and covalently bonded to the nearby PCL,forming a striking contrast to the control in which linear PCL acts as the matrix.The DA bonds crosslinked biodegradable PCL composites exhibit decent mechanical strength(20.7 MPa)even at the MCC fraction of 65 wt%,which is superior to those(5-12.2 MPa)of the highly filled PCL composites(with filler contents of 50-63.8 wt%)reported so far.The proposed approach has sufficient expansibility for the fabrication of the highly filled polymer composites constructed by other types of matrix and fillers.
