In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, ...In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, enabling bigger migration of the cells for formation of the bone tissue regeneration mainly because nanotolith are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin). The objective in this study was to analyze the regeneration capacity of bone defects treated with this bionanocomposite. Histological experiments shows bone tissue formation with high regularity, higher osteoblast activity and osteo-reabsorption activities areas. The results suggest the potential for this new biomaterial as a scaffold for bone tissue regeneration.展开更多
Background: We experienced a very rare complication, that is, an unexpected postoperative paraplegia due to the incidental migration of oxidized regenerated cellulose used for hemostasis of intercostal space bleeding....Background: We experienced a very rare complication, that is, an unexpected postoperative paraplegia due to the incidental migration of oxidized regenerated cellulose used for hemostasis of intercostal space bleeding. Patients and Methods: The objective is to analyze the cause and to take measures against the very rare complication from an empirical analysis and the literature. For a 78-year-old male with suspected lung cancer in the right upper lobe (S1), a thoracotomy was performed. For hemostasis of the bleeding from the 5th intercostal thoracotomy space, we used and placed oxidized regenerated cellulose at the continuous oozing bleeding sites. On the 3rd postoperative day, paralysis beneath thoracic vertebrae level 6 was observed. Immediate computed-tomographic (CT) scanning and magnetic resonance imaging (MRI) displayed a 17 × 9 × 14 mm epidural hematoma in the spinal canal at level 5 of the thoracic vertebrae. An emergent laminectomy for the thoracic vertebra was performed to remove the oxidative cellulose and haematoma, and the compression was released. The paraplegia gradually began to recover and maintain a standing position. After 1 year from the event, the patient can walk by himself with a crutch. Results: The causes were that the oxidative cellulose materials were used for the intercostal bleeding at the open thoracotomy. The migration of the oxidative cellulose materials into the epidural space and into thoracic spinal canal through the intervertebral foramen, or gradual penetration of the oxidative cellulose materials into the spinal canal due to respiratory costal movement. As a measurement of prevention, the hemostat materials should be completely removed after finishing of the hemostasis. In the case of a difficult hemostasis, consultation of an orthopedist or neurosurgeon to perform the appropriate hemostasis in good cooperation is required. Conclusion: If postoperative paraplegia is suspected, immediate CT scanning and/or MRI examination would become powerful diagnostic procedures as soon as possible to start an interventional treatment.展开更多
Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St...Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film.展开更多
The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,...The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.展开更多
Cellulose-based Ultraviolet B(UVB)-shielding films were prepared by coating SnO2 film onto regenerated cellulose(RGC) film through a magnetron sputtering method. The dependence of the crystalline quality and optical p...Cellulose-based Ultraviolet B(UVB)-shielding films were prepared by coating SnO2 film onto regenerated cellulose(RGC) film through a magnetron sputtering method. The dependence of the crystalline quality and optical property of the SnO2 film on the sputtering power was systematically studied. High quality SnO2 film was grown on RGC film at an optimum sputtering power of 150 W. The optical properties of the composite film can be tailored by adjusting the thickness of the SnO2 film. The SnO2/RGC composite film exhibited high visible transparency and excellent UVBshielding capacity, which can be used for protection against short-wave radiation.展开更多
A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree...A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.展开更多
The biodegradability of Aspergillus niger (A. niger), Mucor (M-305) and Trichoderma (T-311) strains on regenerated cellulose films in media was investigated. The results showed that T-311 strain isolated from soil adh...The biodegradability of Aspergillus niger (A. niger), Mucor (M-305) and Trichoderma (T-311) strains on regenerated cellulose films in media was investigated. The results showed that T-311 strain isolated from soil adhered on the cellulose film fragments has stronger degradation effect on the cellulose film than A. niger strain. The weights, molecular weights and tensile strengths of the cellulose films in both shake culture and solid media decreased with incubation time, accompanied by producing CO2 and saccharides. HPLC, IR and released CO2 analysis indicated that the biodegradation products of the regenerated cellulose films mainly contain oligosaccharides, cellobiose, glucose, arabinose, erythrose, glycerose, glycerol, ethanal, formaldehyde and organic acid, the end products were CO2 and water. After a month, the films were completely decomposed by fungi in the media at 30 degrees C.展开更多
Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results...Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.展开更多
Fungal corneal ulcer is one of the leading causes of corneal blindness in developing countries.Corneal scars such as leukoplakia are formed due to inflammation,oxidative stress and non-directed repair,which seriously ...Fungal corneal ulcer is one of the leading causes of corneal blindness in developing countries.Corneal scars such as leukoplakia are formed due to inflammation,oxidative stress and non-directed repair,which seriously affect the patients'subsequent visual and life quality.In this study,drawing inspiration from the oriented structure of collagen fibers within the corneal stroma,we first proposed the directional arrangement of CuTA-CMHT hydrogel system at micro and macro scales based on the 3D printing extrusion method combined with secondary patterning.It played an antifungal role and induced oriented repair in therapy of fungal corneal ulcer.The results showed that it effectively inhibited Candida albicans,Aspergillus Niger,Fusarium sapropelum,which mainly affects TNF,NF-kappa B,and HIF-1 signaling pathways,achieving effective antifungal functions.More importantly,the fibroblasts interacted with extracellular matrix(ECM)of corneal stroma through formation of focal adhesions,promoted the proliferation and directional migration of cells in vitro,induced the directional alignment of collagen fibers and corneal stromal orthogonally oriented repair in vivo.This process is mainly associated with MYLK,MYL9,and ITGA3 molecules.Furthermore,the downregulation the growth factors TGF-βand PDGF-βinhibits myofibroblast development and reduces scar-type ECM production,thereby reducing corneal leukoplakia.It also activates the PI3K-AKT signaling pathway,promoting corneal healing.In conclusion,the oriented CuTA-CMHT hydrogel system mimics the orthogonal arrangement of collagen fibers,inhibits inflammation,eliminates reactive oxygen species,and reduces corneal leukoplakia,which is of great significance in the treatment of fungal corneal ulcer and is expected to write a new chapter in corneal tissue engineering.展开更多
文摘In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, enabling bigger migration of the cells for formation of the bone tissue regeneration mainly because nanotolith are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin). The objective in this study was to analyze the regeneration capacity of bone defects treated with this bionanocomposite. Histological experiments shows bone tissue formation with high regularity, higher osteoblast activity and osteo-reabsorption activities areas. The results suggest the potential for this new biomaterial as a scaffold for bone tissue regeneration.
文摘Background: We experienced a very rare complication, that is, an unexpected postoperative paraplegia due to the incidental migration of oxidized regenerated cellulose used for hemostasis of intercostal space bleeding. Patients and Methods: The objective is to analyze the cause and to take measures against the very rare complication from an empirical analysis and the literature. For a 78-year-old male with suspected lung cancer in the right upper lobe (S1), a thoracotomy was performed. For hemostasis of the bleeding from the 5th intercostal thoracotomy space, we used and placed oxidized regenerated cellulose at the continuous oozing bleeding sites. On the 3rd postoperative day, paralysis beneath thoracic vertebrae level 6 was observed. Immediate computed-tomographic (CT) scanning and magnetic resonance imaging (MRI) displayed a 17 × 9 × 14 mm epidural hematoma in the spinal canal at level 5 of the thoracic vertebrae. An emergent laminectomy for the thoracic vertebra was performed to remove the oxidative cellulose and haematoma, and the compression was released. The paraplegia gradually began to recover and maintain a standing position. After 1 year from the event, the patient can walk by himself with a crutch. Results: The causes were that the oxidative cellulose materials were used for the intercostal bleeding at the open thoracotomy. The migration of the oxidative cellulose materials into the epidural space and into thoracic spinal canal through the intervertebral foramen, or gradual penetration of the oxidative cellulose materials into the spinal canal due to respiratory costal movement. As a measurement of prevention, the hemostat materials should be completely removed after finishing of the hemostasis. In the case of a difficult hemostasis, consultation of an orthopedist or neurosurgeon to perform the appropriate hemostasis in good cooperation is required. Conclusion: If postoperative paraplegia is suspected, immediate CT scanning and/or MRI examination would become powerful diagnostic procedures as soon as possible to start an interventional treatment.
文摘Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film.
文摘The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.
文摘Cellulose-based Ultraviolet B(UVB)-shielding films were prepared by coating SnO2 film onto regenerated cellulose(RGC) film through a magnetron sputtering method. The dependence of the crystalline quality and optical property of the SnO2 film on the sputtering power was systematically studied. High quality SnO2 film was grown on RGC film at an optimum sputtering power of 150 W. The optical properties of the composite film can be tailored by adjusting the thickness of the SnO2 film. The SnO2/RGC composite film exhibited high visible transparency and excellent UVBshielding capacity, which can be used for protection against short-wave radiation.
基金This work was supported by the National Natural Science Foundation of China (No. 59933070) and Laboratory of Cellulose and Lignocellulosic Chemistry, Guangzhou Institute of Chemistry, Chinese Academy of Sciences.
文摘A series of cellulose acetate membranes were prepared by using formamide as additive, and then were hydrolyzed in 4 wt% aqueous NaOH solution for 8 h to obtain regenerated cellulose membranes. The dependence of degree of substitution, structure, porous properties, solubility and thermal stability on hydrolysis time was studied by chemical titration, Fourier transform infrared spectroscopy, scanning electron microscopy, wide-angle X-ray diffraction, and differential scanning calorimetry, respectively. The results indicated that the pore size of the regenerated cellulose membranes was slightly smaller than that of cellulose acetate membrane, while solvent-resistance, crystallinity and thermostability were significantly improved. This work provides a simple way to prepare the porous cellulose membranes, which not only kept the good pore characteristics of cellulose acetate membranes, but also possessed solvent-resistance, high crystallinity and thermostability. Therefore, the application range of cellulose acetate membranes can be expanded.
基金The work ws supported by the State Economy and Trade Commission of China.
文摘The biodegradability of Aspergillus niger (A. niger), Mucor (M-305) and Trichoderma (T-311) strains on regenerated cellulose films in media was investigated. The results showed that T-311 strain isolated from soil adhered on the cellulose film fragments has stronger degradation effect on the cellulose film than A. niger strain. The weights, molecular weights and tensile strengths of the cellulose films in both shake culture and solid media decreased with incubation time, accompanied by producing CO2 and saccharides. HPLC, IR and released CO2 analysis indicated that the biodegradation products of the regenerated cellulose films mainly contain oligosaccharides, cellobiose, glucose, arabinose, erythrose, glycerose, glycerol, ethanal, formaldehyde and organic acid, the end products were CO2 and water. After a month, the films were completely decomposed by fungi in the media at 30 degrees C.
文摘Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.
基金Tsinghua Berkeley Shenzhen Institute and the Project of Basic Research of Shenzhen,China(JCYJ20170412101508433&JCYJ20180507183655307)National Key Research and Development Program of China(2023YFE0203100)National Natural Science Foundation of China(Grant Nos.82271051,82070926).
文摘Fungal corneal ulcer is one of the leading causes of corneal blindness in developing countries.Corneal scars such as leukoplakia are formed due to inflammation,oxidative stress and non-directed repair,which seriously affect the patients'subsequent visual and life quality.In this study,drawing inspiration from the oriented structure of collagen fibers within the corneal stroma,we first proposed the directional arrangement of CuTA-CMHT hydrogel system at micro and macro scales based on the 3D printing extrusion method combined with secondary patterning.It played an antifungal role and induced oriented repair in therapy of fungal corneal ulcer.The results showed that it effectively inhibited Candida albicans,Aspergillus Niger,Fusarium sapropelum,which mainly affects TNF,NF-kappa B,and HIF-1 signaling pathways,achieving effective antifungal functions.More importantly,the fibroblasts interacted with extracellular matrix(ECM)of corneal stroma through formation of focal adhesions,promoted the proliferation and directional migration of cells in vitro,induced the directional alignment of collagen fibers and corneal stromal orthogonally oriented repair in vivo.This process is mainly associated with MYLK,MYL9,and ITGA3 molecules.Furthermore,the downregulation the growth factors TGF-βand PDGF-βinhibits myofibroblast development and reduces scar-type ECM production,thereby reducing corneal leukoplakia.It also activates the PI3K-AKT signaling pathway,promoting corneal healing.In conclusion,the oriented CuTA-CMHT hydrogel system mimics the orthogonal arrangement of collagen fibers,inhibits inflammation,eliminates reactive oxygen species,and reduces corneal leukoplakia,which is of great significance in the treatment of fungal corneal ulcer and is expected to write a new chapter in corneal tissue engineering.
