Electrospun nanofiber scaffolds for soft and hard tissue regeneration / 中国组织工程研究

BACKGROUND:Currently,electrospun nanofibers,which are biomimetic materials of natural extracellular matrix and contain a three-dimensional network of interconnected pores,have been successfully used as scaffolds for various tissue regeneration,but are still faced with the challenge of extending the biomaterials into three-dimensional structures to reproduce the physiological,chemical as well as mechanical properties of the tissue microenvironment. OBJECTIVE:To summarize the process and principles of electrostatic spinning and to explore the applications of the resulting electrospun nanofibers in tissue regeneration of skin,blood vessels,nerves,bone,cartilage and tendons/ligaments. METHODS:With"electrospinning,electrospun nanofibers,electrospun nanofiber scaffolds,tissue regeneration"as the Chinese and English search terms,Google Academic Database,PubMed,and CNKI were searched,and finally 88 articles were included for review. RESULTS AND CONCLUSION:(1)The electrospun nanofibers are a natural fibrous extracellular matrix mimetic material and contain a three-dimensional network of interconnected pores that have been successfully used as scaffolds for a variety of tissue regeneration applications.(2)Several papers have described the great potential of electrospun nanofiber scaffolds applied to the regeneration of skin,blood vessels,nerves,bones,cartilage and tendons/ligaments,providing a solid theoretical basis for its final application in clinical disease treatment,or for its transformation into practical products to enter the market.(3)However,the current research results are mostly based on cell experimental research results in vitro,and whether it can be finally applied to human body still needs clinical verification.(4)At present,many kinds of electrospun products for various clinical needs have been commercialized in and outside China,indicating that the research field of electrospun nanofiber scaffolds for soft and hard tissue regeneration has great research value and application potential.

An Economic Analysis of Processing of Rainfed Cotton in Virudhunagar District of Tamil Nadu, India

The cotton processing industry holds a significant position in the Indian economy as the second-largest labor-intensive activity after agriculture, providing direct and indirect employment to the Indian population. Given the commercial importance of cotton at the national and State levels, there is a recognized need to thoroughly examine the cotton value chain, which includes producers and various stakeholders. Hence this study was proposed and conducted in 2022 covering 90 rainfed cotton growers, seven ginners, six spinners and twenty-seven weavers in Virudhunagar district. The findings of the study revealed that the cotton producers receive a share of (Rs.7006.1 per quintal) 48.37 per cent of the consumer rupee per quintal. The cost and returns analysis showed that, the stakeholders at different level i.e ginners, spinners and weavers incurred Rs.7591.11, Rs.18089.64 and Rs.31251.22 to process per quintal of product i.e kapas, lint, yarn and fabrics production and received as returns of Rs.10587, Rs. 27354.16 and Rs.48934.00 by them. The weavers had the highest financial profitability (1.52) in cotton value chain, followed by spinners (1.47), ginners (1.35) and farmers (1.11).

Evaluation of three different remineralizing agents on artificially demineralized enamel lesions Using scanning electron microscopy-energy dispersive X-ray and magic-angle spinning nuclear magnetic resonance - An in vitro study

Aim: Demineralization can be arrested or reversed when remineralization agents are applied to incipient carious or noncavitated carious lesions. A large number of therapeutic agents, including nonfluoridated products, have been developed to promote enamel remineralization. This study aims to evaluate the efficacy of different remineralizing agents on artificially demineralized enamel lesions. Materials and Methods: The present in vitro study was conducted on 75 sound premolars divided into three groups of normal, demineralized (n = 15 each), and remineralized teeth (n = 45). The remineralized teeth were further subdivided into three groups (n = 15) as remineralized with 2% sodium fluoride (NaF), 2% NaF, and Psoralea corylifolia (bakuchi) and white mineral trioxide aggregate. Specimens of each group were treated with the above-mentioned remineralizing agents and then subjected to Vickers hardness number (VHN), scanning electron microscopy–energy dispersive X-ray (SEM-EDX), and magic-angle spinning nuclear magnetic resonance (MAS-NMR) for further evaluation. Results: The test results showed significantly the highest VHN and the emission peak of elements under the EDX test, such as calcium, phosphorous, oxygen, and fluorine with remineralized with NaF + bakuchi. MAS-NMR spectra showed fluorine and phosphorous peak in a group with NaF + bakuchi indicative of the increase in remineralization. NaF + bakuchi showed effective results in VHN, SEM-EDX, and MAS-NMR with no antagonist interaction. Conclusion: Thus, P. Corylifolia presents an advantage in enhancing remineralization and inhibiting demineralization for early carious lesions and can be used as a herbal extract for effective reduction in pathogenic bacteria.

An injectable hydrogel/staple fiber composite for sustained release of CA4P and doxorubicin for combined chemotherapy of xenografted breast tumor in mice / 南方医科大学学报

OBJECTIVE@#To prepare an injectable hydrogel/staple fiber composite loaded with combretastain A-4 disodium phosphate (CA4P) and doxorubicin (DOX) and evaluate its antitumor efficacy via intratumoral injection.@*METHODS@#DOX-loaded PELA staple fibers (FDOX) were prepared using electro-spinning and cryo-cutting, and the drug distribution on the surface of the fibers was observed using a fluorescence microscope, and the encapsulation efficiency and loading capacity of FDOX were determined with a fluorospectro photometer. The fibers were then dispersed in CA4P-loaded PLGA-PEG-PLGA tri-block polymer solution at room temperature to obtain the hydrogel/staple fiber composite (GCA4P/FDOX). The thermo-sensitivity of this composite was determined by a test tube inverting method. An ultraviolet spectrophotometer and a fluorospectrophotometer were used to detect the release profile of CA4P and DOX, respectively. We observed in vivo gel formation of the composite after subcutaneous injection in mice. The in vitro cytotoxicity of GCA4P/FDOX composite in MCF-7 and 4T1 cells was assessed using cell Counting Kit-8 (CCK-8) reagent. In a mouse model bearing breast tumor 4T1 cell xenograft, we evaluated the antitumor efficacy of the composite by monitoring tumor growth within 30 days after intratumoral injection of the composite. HE staining, immunohistochemistry for Ki67 and immunofluorescence (TUNEL) assay were used for pathological examination of the tumor tissues 21 days after the treatments.@*RESULTS@#The average length of FDOX was 4.0±1.3 μm, and its drug loading capacity was (2.69±0.35)% with an encapsulation efficiency of (89.70±0.12)%. DOX was well distributed on the surface of the fibers. When the temperature increased to 37 ℃, the composite rapidly solidified to form a gel in vitro. Drug release behavior test showed that CA4P was completely released from the composite in 5 days and 87% of DOX was released in 30 days. After subcutaneous injection, the composite solidified rapidly without degradation at 24 h after injection. After incubation with GCA4P/FDOX for 72 h, only 30.6% of MCF-7 cells and 28.9% of 4T1 cells were viable. In the tumor-bearing mice, the tumor volume was 771.9±76.9 mm3 in GCA4P/FDOX treatment group at 30 days. Pathological examination revealed obvious necrosis of the tumor tissues and tumor cell apoptosis induced by intratumoral injection of G4A4P/FDOX.@*CONCLUSION@#As an efficient dual drug delivery system, this hydrogel/staple fiber composite provides a new strategy for local combined chemotherapy of solid tumors.

Tissue-engineered cartilage nanoscaffolds prepared with collagen, hyaluronic acid and chondroitin sulfate / 中华医学美学美容杂志

Objective:To explore the possibility of constructing tissue-engineered cartilage three-dimensional nanoscaffolds with collagen Ⅱ (COLⅡ), hyaluronic acid (HA) and chondroitin sulfate (CS).Methods:The tissue-engineered cartilage scaffolds were prepared by electrospinning techniques with the mixture COLⅡ-HA-CS solvent, which dissolved by 3-trifluoroethanol-water. The surface topography was observed under electron microscope (SEM). And the diameter of nanofibers, the water absorption rate, contact angle and degradation rate were also detected. Generation 2 rabbit chondrocytes were seeded into the scaffold. The cell survival rate and proliferation were evaluated by Cell Counting Kit-8.Results:When the concentration range of electrospinning was 80-120 mg/ml and the mixing ratio of Col, HA and CS was 6-8∶1∶1-2, the tissue engineered cartilage nanoscaffolds could be successfully prepared. Their diameters were mainly distributed between 126.5±23.3 nm and 374.7±14.1 nm. The scaffolds had satisfactory hydrophilicity and degradability. The chondrocytes could well adhere and proliferate on the scaffold.Conclusions:The COLⅡ-HA-CS tissue-engineered cartilage nanoscaffolds have good physical and biological properties, which suggests its promising application in tissue-engineered cartilage.

Correlation Subjective Workload With Productivity Of Spinning Workers In Pt. Delta Merlin Sandang Tekstil I Sragen

@#Introduction: Workload is the burden that must be completed by workers of a job that is done, including the spinning workers. The excessive workload in the spinning section can be a trigger factor for the onset of stress, which can then have an impact on work productivity. The purpose of this research was to determine the relationship between subjective workload and work productivity in the spinning workers of PT. Delta Merlin Sandang Tekstil I Sragen. Methods: This is an observational research with a cross-sectional design. The research population was 202 spinning workers with a large sample of 133 spinning workers taken using the simple random sampling method. The independent variable of this research was subjective workload while the dependent variable was work productivity. Data collection was carried out using a questionnaire adapted from previous research. Data were analyzed with the spearman correlation test. Results: The result showed that 87.2% of respondents had a massive subjective workload level, and 68.4% of respondents have a moderate level of work productivity. Statistical test results showed that there was a relationship between subjective workload and work productivity (p = 0.000). Conclusion: The level of workload productivity and work productivity had a significant relationship. The relationship between subjective workload and work productivity was a moderate level relationship. The advice that can be given was that the company is expected to carry out work time following statutory regulations and take preventative measures against factors that cause a decrease in worker productivity.

Box-Behnken response surface method optimized BSP/PVA wet spinning process and fiber performance evaluation / 中草药

Objective: To optimize Bletilla striata polysaccharide (BSP)/polyvinylalcohol (PVA) wet spinning process by Box- Behnken response surface method and prepare the composite fiber and performe their structural characterization and performance evaluation. Methods: Taking the OD value of three types of mechanical property data (breaking force, breaking strength and elongation at break) of the fiber as the evaluation index, five factors (BSP mass fraction, PVA mass fraction, volumetric mix ratio of BSP/PVA, coagulation time and spinning speed) were investigated by single factor experiments. On the basis of the results of single factor experiments, three factors (BSP mass fraction, volumetric mix ratio of BSP/PVA, coagulation time) were investigated by response surface method to optimize BSP/PVA composite fiber wet spinning process. The morphology, structure, thermal property, and absorption property of the fibers were characterized and analyzed by SEM, IR, DSC, and water absorption test. Berberine hydrochloride (BH) was used as model drug to evaluate the drug loading property of the composite fiber and antibacterial activity of the drug loading fiber. Results: The optimal spinning process of composite fiber were as follows: BSP mass fraction was 7.5%, volume mixing ratio of BSP/PVA was 1:1 and coagulation time was 3 min. The composite fiber had a dense surface and formed a three-dimensional network structure inside, generated intermolecular forces, which enhanced the thermal and mechanical properties, and exhibited excellent water absorption capacity. The encapsulation efficiency of the composite fiber reached 70.2%. And the drug loading fiber formed obvious inhibition zone in the bacteriostatic zone test, which presented excellent antibacterial effect against E. coli and S. aureus. Conclusion: The optimized spinning process is feasible and low cost. The prepared composite fiber has better physical property and certain coating ability, and its application in the field of biomedical textiles is worth further study.

Effects of sustained-release atorvastatin calcium nanofiber scaffold on cell adhesion and proliferation / 中国组织工程研究

BACKGROUND: Statins plays a significant role in regulating blood lipids, treating and preventing cardiovascular and cerebrovascular diseases. Studies have shown that statins has certain potential in promoting bone formation and treating osteoporosis. OBJECTIVE: To prepare the drug release scaffolds for the sustained release of atorvastatin calcium, which consist of bovine serum albumin microspheres and polycaprolactone electrostatic spinning fibers, and to investigate the effects of the drug sustained release scaffolds on osteoblast adhesion and proliferation. METHODS: Bovine serum albumin microspheres containing atorvastatin calcium were prepared by desolvation. A layer of chitosan was coated on the surface of the bovine serum albumin microspheres by electrostatic adsorption, which can increase the stability of the microspheres. Bovine serum albumin microspheres were purified and lyophilized for later use. The lyophilized powder of microspheres was dissolved in organic solvent. An appropriate amount of hydroxyapatite was added in the solvent. The nanofiber scaffolds for sustained release of atorvastatin calcium were prepared via electrospinning. The micromorphology, degradation performance, and sustained-release performance of the nanofiber scaffolds were characterized. The prepared nanofiber scaffolds for sustained-release of atorvastatin calcium were co-cultured with MC3T3-E1 cells to observe cell adhesion and proliferation. RESULTS AND CONCLUSION: (1) Transmission electron microscopy revealed that the shape of the bovine serum albumin nanospheres was regular and circular. Bovine serum albumin nanospheres were discarded in the electrostatic spinning fibers. The basic morphology of the microspheres was retained. (2) Scanning electron microscopy revealed that the nanofibers used for preparation of nanofiber scaffolds for sustained-release of atorvastatin calcium were composed of filaments with uniform diameters and continuous smooth surface. Filaments were intertwined to form a network structure. (3) The nanofiber scaffolds exhibited the fastest degradation in the first month. The material was incomplete when degraded for 3 months. (4) The nanofiber scaffolds had the ability to slow down the release of drugs. The effect could last for more than 1 month. The overall process of drug release was similar to the zero-order kinetic process. (5) The nanofiber scaffolds for sustained-release of atorvastatin calcium can promote MC3T3-E1 cell adhesion and proliferation. (6) These results suggest that the nanofiber scaffolds for sustained-release of atorvastatin calcium have good biocompatibility and can promote the adhesion and proliferation of osteoblasts.

P38/akt pathway regulates the oriented differentiation of bone marrow mesenchymal stem cells in nanofiber annulus fibrosus scaffolds with different spatial structures / 中国组织工程研究

BACKGROUND: Previous studies have shown that a variety of materials can be used for the construction of tissue engineering scaffolds. The topological structure of the scaffold surface has a regulatory effect on the biological behaviors such as stem cell proliferation and differentiation, but the specific mechanism is still unclear. OBJECTIVE: To investigate the role of P38 and Akt pathways in the oriented differentiation of bone marrow mesenchymal stem cells in nanofiber scaffolds. METHODS: Three kinds of nanofiber scaffolds (AFS, AYS, 3-DPS) with different structures were constructed. Rat bone marrow mesenchymal stem cells were inoculated on the surface of three kinds of nanofiber scaffolds. After osteogenic induction, cell morphology, adhesion and proliferation were detected. mRNA expression levels of key phenotype molecules (COLIα1, COLIIα1, Aggrecan, Sox-9) were measured using qRT-PCR. Intracellular P38, AKT, ERK1/2 and JNK expression was detected by western blot assay. RESULTS AND CONCLUSION: After 4 and 8 hours of culture, cell adhesion rate of the 13-DPS scaffold group was higher than that of the AFS and AYS scaffold groups (P<0.05). After 7 days of culture, cells of the 13-DPS scaffold group proliferated faster than those of AFS and AYS scaffold groups (P<0.05). Bone marrow mesenchymal stem cells adhered firmly and grew well on three kinds of scaffolds. Fibroblast-like growth was observed on the AFS and AYS scaffolds and chondrocyte-like growth was observed on the 3-DPS scaffold. After 3 weeks of cartilage induction, mRNA expression of COLIIα1, Aggrecan and Sox-9 was higher, and the mRNA expression of COLIα1 was lower, in the 3-DPS scaffold group compared with the other two groups (both P<0.05). After 3 weeks of cartilage induction, relative expression level of p-AKT and p-P38 in the 3-DPS scaffold group was significantly higher than that in the other two groups (both P<0.05). There were no significant differences in AKT total protein and ERK1/2, JNK, P38, p-ERK1/2, p-JNK and p-P38 protein expression levels among three groups. These findings suggest that nanofiber annulus fibrosus scaffolds with different spatial structures can induce the oriented differentiation of bone marrow mesenchymal stem cells through the P38 and AKT pathway, which were the downstream of the Integrin-FAK signaling pathway.

Fabrication and evaluation of biomimetic biodegradable tissue-engineered annulus fibrosus scaffold / 中国组织工程研究

BACKGROUND: It is still difficult to construct tissue-engineered anulus fibrosus scaffolds which have bionic structure, suitable biodegradability and good biocompatibility. OBJECTIVE: To fabricate bionic biodegradable scaffolds with polycaprolactone (PCL) and polydioxanone (PDS) and evaluate the feasibility as a tissue-engineered annulus fibrosus scaffold. METHODS: Five groups of scaffolds at different PCL/PDS proportions were prepared by melt spinning technique: PCL, PCL/PDS70/30, PCL/PDS50/50, PCL/PDS30/70, and PDS groups. Scanning electron microscopy was used to observe the structure and measure the fiber diameter and pore size of these prepared scaffolds. The mechanical properties and contact angle of the scaffolds were measured. The in vitro and in vivo biodegradation of the scaffolds were observation by in vitro simulation and subcutaneous implantation. The expression of inflammatory factors interleukin-1β and tumor necrosis factor-α in the biodegraded tissues was detected. Human Wharton’s jelly mesenchymal stem cells were cultured for 7 days. Cell viability and proliferation was determined by live/dead cell staining. This study was approved by the Medical Ethics Committee of Tianjin Hospital, China on March 2, 2016. RESULTS AND CONCLUSION: Scanning electron microscopy results showed that the thickness of the scaffold fibers was uniform and the angle between fibers was 60°. The mechanical properties analysis showed that the tensile and compressive modulus of the PDS group was the lowest, which did not meet the mechanical requirements of the anulus fibrosus; the tensile and compressive modulus in the PCL group was the highest, and those in the PCL/PDS70/30 and PCL/PDS50/50 group were moderate. Hydrophilicity test showed that higher PDS proportion led to better hydrophilicity. Biodegradation test showed that the biodegradation of pure PDS and PCL/PDS30/70 was too fast, that of PCL was too slow, and that of PCL/PDS70/30 and PCL/PDS50/50 was appropriate. Analysis of inflammatory response around the biodegraded tissue showed that higher proportion of PCL in the scaffold resulted in more severe inflammatory response. CCK-8 and live/dead cell staining showed that human Wharton’s jelly mesenchymal stem cells had good proliferative activity and high survival rate in the PCL/PDS70/30, PCL/PDS50/50, and PCL/PDS30/70 groups. These results suggest that scaffolds in the PCL/PDS70/30 and PCL/PDS50/50 groups can simulate the structure of natural annulus fibrosus, have appropriate biodegradability, excellent mechanical properties and good biocompatibility, which make it a suitable candidate for tissue-engineered annulus fibrosus scaffold.

Viability Assays of PLLA Fibrous Membranes Produced by Rotary Jet Spinning for Application in Tissue Engineering

Abstract Tissue engineering suggests different forms to reconstruct tissues and organs. One of the ways is through the use of polymeric biomaterials such as poly(L-lactic acid) (PLLA). PLLA is a recognized material in tissue engineering due to its characteristics as biocompatibility and bioresorbability. In this work PLLA fibrous membranes were produced by a simple technique known as rotary jet spinning. The rotary jet spinning consists of fibrous membranes production, with fibers of scale nano/micrometric, from a polymeric solution through the centrifugal force generated by the equipment. The membranes formed were subjected to preliminary in vitro assays to verify the cytotoxicity of the membranes made in contact with the cells. Direct cytotoxicity assays were performed through the MTT, AlamarBlue® and Live/Dead® tests, with fibroblastic and osteoblastic cells. The results obtained in this study showed that PLLA membranes produced by rotary jet spinning showed promising results in the 24-hours contact period of the cells with the PLLA fibrous membranes. The information presented in this preliminary study provides criteria to be taken in the future procedures that will be performed with the biomaterial produced, aiming at its improvement.

Production of fibrous polymer scaffolds for tissue engineering using an automated solution blow spinning system

Abstract Introduction Solution blow spinning (SBS) and airbrushing are two techniques that can be used as alternatives to electrospinning in the production of fibrous scaffolds for tissue engineering (TE). SBS seems particularly interesting due to its versatility, however, it has not been much explored and no automated SBS systems were found in the literature. Therefore, the present work aimed to develop such equipment and compare the results to those found for airbrushing, considering the same set of parameters. Methods A new SBS set up, composed of a specially designed nozzle with automated movement, a syringe pump and a compressor, was used to produce fibrous poly (ε-caprolactone) (PCL) mats. The airbrushed fibers were produced under the same conditions, and samples of both types of mats were imaged using scanning electron microscopy (SEM) to compare them in terms of microstructure and fiber diameter. Results The SBS system was robust and performed well, in terms of movement and fiber deposition. In comparison to airbrushing's, SBS mats presented different microstructural characteristics (considering the parameters used). Conclusion The biggest advantage over airbrushing may be its versatility and simple automation, which may improve sample reproducibility, especially considering scaled up processes. To further improve this apparatus, a better understanding of how process variables interfere in the microstructure is needed, as well as more sophisticated interface and operation.

Ovarian cancer in a former asbestos textile factory worker: a case report

BACKGROUND: The International Agency for Research on Cancer (IARC) defined that asbestos is a group 1 substance that causes lung cancer, mesothelioma (pleura and peritoneum), laryngeal cancer, and ovarian cancer in humans. Many studies on lung cancer, and mesothelioma caused by asbestos exposure have been conducted, but there was no case report of ovarian cancer due to asbestos exposure in Korea. We describe a case of ovarian cancer caused by asbestos exposure in a worker who worked at an asbestos textile factory for 3 years and 7 months in the late 1970s. CASE PRESENTATION: A 57-year-old woman visited the hospital because she had difficulty urinating. Ovarian cancer was suspected in radiologic examination, and exploratory laparotomy was performed. She was diagnosed with epithelial ovarian cancer. The patient did not undergo postoperative chemotherapy and recovered. She joined the asbestos factory in March 1976 and engaged in asbestos textile twisting and spinning for 1 year, 2 years and 7 months respectively. In addition, she lived near the asbestos factory for more than 20 years. There was no other specificity or family history. CONCLUSION: Considering the patient’s occupational and environmental history, it is estimated that she had been exposed to asbestos significantly, so we determined that ovarian cancer in the patient is highly correlated with the occupational exposure of asbestos and environmental exposure is a possible cause as well. Social devices are needed to prevent further exposure to asbestos. It is also necessary to recognize that ovarian cancer can occur in workers who have previously been exposed to asbestos, and the education and social compensation for those workers are needed.

Adhesión y proliferación de las células troncales mesenquimales de médula ósea en andamios fibrilares de poli (ácido L-láctico) (PLA) / Adhesion and proliferation of bone marrow mesenchymal stem cells onto poli-L lactic acid (PLA) fiber scaffolds

Resumen: Los andamios fibrilares han recibido un enorme interés como futuros biomateriales con potencial aplicación en el campo de la biomedicina regenerativa. En este sentido, hemos optimizado los parámetros para la síntesis de diferentes concentraciones (6, 7, y 10 %) de andamios de ácido poli-láctico (PLA) por la técnica de hilado por propulsión de gas (AJS). Dichos andamios fueron caracterizados por Microscopía Electrónica de Barrido (SEM) y por espectrometría Infrarroja con Transformada de Fourier (FTIR). Nuestros resultados mostraron que los andamios son fibrilares con diámetros en escalas nanométricas. Asimismo; se estudió la biocompatibilidad celular in vitro al realizar ensayos de adhesión, proliferación y de interacción célula-material al cultivar células troncales mesenquimales derivadas de médula ósea. Nuestros datos indican que las membranas fibrilares de PLA aumentan la respuesta celular, no son citotóxicas al compararse con las películas delgadas de PLA. Por lo tanto; el método de síntesis propuesto tiene potencial para la fabricación de membranas hiladas con una facilidad de procesamiento y podría ser un prometedor biomaterial económico con futuras aplicaciones en la regeneración de tejidos.

Abstract: Fiber scaffolds have received increasing interest as promising biomaterials for potential application in the field of tissue regeneration. In this sense, we optimized the parameters for the synthesis of different concentrations (6, 7, and 10 %) of poly-lactic acid (PLA) scaffolds by air jet spinning technology (AJS). The PLA scaffolds were characterized by Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR) analysis. Our results by SEM micrographs showed that scaffolds have a fibrilar morphology with nanoscale diameter of fibers. Biocompatibility assay was observed through an in vitro experiment based on cell attachment, MTT and cell-material interaction assay when culturing bone marrow-derived mesenchymal stem cells onto the PLA spun membrane scaffolds. Our data indicate that fiber membrane of PLA scaffold increase the cellular response, are not cytotoxic when compared to thin films of PLA. Thus; the proposed synthesis method has potential for easy processing of spun fibrilar scaffolds with good biocompatibility and could be a promising economical biomaterial with future potential applications in tissue regeneration.

Microfluidic Spinning of the Fibrous Alginate Scaffolds for Modulation of the Degradation Profile

In tissue engineering, alginate has been an attractive material due to its biocompatibility and ability to form hydrogels, unless its uncontrollable degradation could be an undesirable feature. Here, we developed a simple and easy method to tune the degradation profile of the fibrous alginate scaffolds by the microfluidic wet spinning techniques, according with the use of isopropyl alcohol for dense packing of alginate chains in the microfiber production and the increase of crosslinking with Ca²⁺ ion. The degradation profiling was analyzed by mass losses, swelling ratios, and also observation of the morphologic changes. The results demonstrated that high packing density might be provided by self-aggregation of polymer chains through high dipole interactions between sheath and core fluids and that the increase of crosslinking rates could make degradation of alginate scaffold controllable. We suggest that the tunable degradation of the alginate fibrous scaffolds may expand its utilities for biomedical applications such as drug delivery, in vitro cell culture, wound healing, tissue engineering and regenerative medicine.

Risk assessment of gastric cancer associated with asbestosis: a case report

BACKGROUND: The International Agency for Research on Cancer classifies asbestos as belonging to Carcinogen Group 2A for gastric cancer. We herein report a case of gastric cancer associated with asbestosis and describe the work-related and risk assessments of asbestos exposure for gastric cancer. CASE PRESENTATION: The 66-year-old male patient in our case worked in asbestos spinning factories. His level of cumulated asbestos fiber exposure was estimated to be 38.0-71.0 f-yr/cc. Thus, the Excess Life Cancer Risk for lung cancer associated with asbestos exposure was 9,648x10-5, almost 9,600 times the value recommended by the United States of America Environmental Protection Agency (1 x 10-5). The relative risk of developing lung cancer for this patient was more than 25 f-yr/cc, a well-known criterion for doubling the risk of lung cancer. CONCLUSION: The patient's exposure to high-dose asbestos was sufficient to increase his risk of gastric cancer because as the risk of lung cancer increased, the risk of gastric cancer was due to increase as well. Therefore, occupational asbestos fiber exposure might be associated with gastric cancer in this case.

Spinning-induced Rhabdomyolysis: Eleven Case Reports and Review of the Literature

Non-traumatic exertional rhabdomyolysis (exRML) occurs in individuals with normal muscles when the energy supplied to the muscle is insufficient. Here, we report 11 cases of spinning-induced rhabdomyolysis and review related literature. Spinning is a kind of indoor bicycle sport. The 11 patients who were diagnosed with exRML and admitted to CHA Bundang Medical Center were female and their ages ranged from 15 to 46 years. Two to three days prior to the presentation, the patients had attended a spinning class for the first time. All the patients had been otherwise healthy without any known medical illnesses. They were successfully treated without any complications, except mild non-symptomatic hypocalcemia. However, in the literature, severe complications such as compartment syndrome or acute kidney injury had been reported in relation to exRML including spinning-induced rhabdomyolysis. This spinning exercise needs prior guidelines and specific warnings to prevent exertional rhabdomyolysis.

Different effects of two hemostases in elderly patients after radial artery intervention / 现代临床护理

Objective To compare the hemostatic efficacies of radial artery balloon and spinning hemostat in elderly patients after radial artery intervention.Methods Eighty elderly patients undergoing transradial coronary intervention were randomly divided into balloon and spinning hemostat groups,with 40 cases in each group.After operation,balloons and spinning hemostats were used for hemostasis,respectively.The two groups were compared in terms of hemostatic effect,comfort degree and incidence of complications.Results These was no difference in hemostatic effect between the two groups(P>0.05).The balloon hemostat group was better than the spinning hemostat in respect of comfort degree.The incidences of ischemia and vagal reflex in the balloon hemostat group were significantly lower than the spinning hemostat group(P<0.05).Conclusion The balloon hemostat for radial artery intervention is more suitable for elderly patients undergoing oral treatment.

A Review of Sheep Wool Quality Traits.

The commercial value of unprocessed wool is determined by its intrinsic quality; an indication of capacity to meet both processor and consumer demands. Wool quality is evaluated through routine assessment of characteristics that include mean fibre diameter, coefficient of variation, staple characteristics, comfort factor, spinning fineness, fibre curvature and clean fleece yield. The association between these characteristics with wool quality stems from their correlation with raw wool processing performance in terms of speed, durability, ultimate use as apparel or carpet wool, and consumer satisfaction with the end-product. An evaluation of these characteristics allows wool quality to be objectively quantified prior to purchase and processing. The primary objective of this review was to define and explore these aforementioned key wool characteristics, focusing on their impact on quality, desirable parameters and methodology behind their quantification. An in-depth review of relevant published literature on these wool characteristics in sheep is presented.