Preparation of silk fibroin/hyaluronic acid composite hydrogel based on thiol-ene click chemistry / 浙江大学学报·医学版

OBJECTIVES@#To design and prepare silk fibroin/hyaluronic acid composite hydrogel.@*METHODS@#The thiol modified silk fibroin and the double-bond modified hyaluronic acid were rapidly cured into gels through thiol-ene click polymerization under ultraviolet light condition. The grafting rate of modified silk fibroin and hyaluronic acid was characterized by 1H NMR spectroscopy; the gel point and the internal microstructure of hydrogels were characterized by rheological test and scanning electron microscopy; the mechanical properties were characterized by compression test; the swelling rate and degradation rate were determined by mass method. The hydrogel was co-cultured with the cells, the cytotoxicity was measured by the lactate dehydrogenase method, the cell adhesion was measured by the float count method, and the cell growth and differentiation on the surface of the gel were observed by scanning electron microscope and fluorescence microscope.@*RESULTS@#The functional group substitution degrees of modified silk fibroin and hyaluronic acid were 17.99% and 48.03%, respectively. The prepared silk fibroin/hyaluronic acid composite hydrogel had a gel point of 40-60 s and had a porous structure inside the gel. The compressive strength was as high as 450 kPa and it would not break after ten cycles. The water absorption capacity of the composite hydrogel was 4-10 times of its own weight. Degradation experiments showed that the hydrogel was biodegradable, and the degradation rate reached 28%-42% after 35 d. The cell biology experiments showed that the cytotoxicity of the composite gel was low, the cell adhesion was good, and the growth and differentiation of the cells on the surface of the gel were good.@*CONCLUSIONS@#The photocurable silk fibroin/hyaluronic acid composite hydrogel can form a gel quickly, and has excellent mechanical properties, adjustable swelling rate and degradation degree, good biocompatibility, so it has promising application prospects in biomedicine.

Antimicrobial activity of comfort related properties of silk treated with herbal extracts in making of reusable masks

The study was aimed at divulging an eco-friendly antimicrobial finish on 100 % silk woven fabric. The leaves' extract of Azadirachata indica, Butea monosperma and Litche chinensis were used as the development of eco-friendly antimicrobial finish. The antimicrobial property and comfort related property were checked before and after applying antimicrobial finish. In comfort related property absorbency & air permeability were checked. The ASTEM E2149 Shake Flask method was used to check antimicrobial finish and AATCC method was used for checking fabric property. One way ANOVA statistical test was applied for analysis of results. The FTIR and SEM results showed the presences of finish on fabrics. In comfort related property, absorbency and air permeability was increased. The results showed that antimicrobial finish made 100% reduction against microorganism up to 25 washes which can be used in making reusable masks fight against COVID- 19.

Review of genetic diversity and breed identification of black-bone silky fowl / 中国中药杂志

Black-bone silky fowl, sweet, pungent, and hot-natured, is one of the valuable domesticated birds with special economic value in China's genebank of poultry breed, which has a long history of medicinal and edible uses. It has the effects of tonifying liver and kidney, replenishing Qi and blood, nourishing yin, clearing heat, regulating menstruation, invigorating spleen, and securing essence. Therefore, it has remarkable efficacy of enhancing physical strength, tonifying blood, and treating diabetes and gynecological diseases. Various local black-bone silky fowl breeds have been generated due to the differences in environmental conditions, breed selection, and rearing conditions in different areas of China, which are mainly concentrated in Taihe, Wan'an, and Ji'an in Jiangxi province and Putian, Jinjiang, and Yongchun in Fujian province. The indigenous chicken breeds in China have different body sizes, appearance, coat colors, etc. The complex lineages lead to extremely unstable genetic traits. The diverse breeds similar in appearance result in the confusion in the market of silky fowl breeds. With the rapid development of molecular biological technology, the genetics of black-bone silky fowls has been intensively studied. This article reviews the research progress of the germplasm resources, genetic diversity, and breed identification of black-bone silky fowl in China at the morphology, chromosome, protein, and DNA levels. Further, it introduces the principles, application status, and limitations of DNA markers such as mitochondrial DNA, microsatellite markers, and SNPs. This review provides a theoretical basis for the mining of elite trait genes and the protection and utilization of local black-bone silky fowl germplasm resources in China.

The osteogenesis of Ginsenoside Rb1 incorporated silk/micro-nano hydroxyapatite/sodium alginate composite scaffolds for calvarial defect / 国际口腔科学杂志·英文版

Ginsenoside Rb1, the effective constituent of ginseng, has been demonstrated to play favorable roles in improving the immunity system. However, there is little study on the osteogenesis and angiogenesis effect of Ginsenoside Rb1. Moreover, how to establish a delivery system of Ginsenoside Rb1 and its repairment ability in bone defect remains elusive. In this study, the role of Ginsenoside Rb1 in cell viability, proliferation, apoptosis, osteogenic genes expression, ALP activity of rat BMSCs were evaluated firstly. Then, micro-nano HAp granules combined with silk were prepared to establish a delivery system of Ginsenoside Rb1, and the osteogenic and angiogenic effect of Ginsenoside Rb1 loaded on micro-nano HAp/silk in rat calvarial defect models were assessed by sequential fluorescence labeling, and histology analysis, respectively. It revealed that Ginsenoside Rb1 could maintain cell viability, significantly increased ALP activity, osteogenic and angiogenic genes expression. Meanwhile, micro-nano HAp granules combined with silk were fabricated smoothly and were a delivery carrier for Ginsenoside Rb1. Significantly, Ginsenoside Rb1 loaded on micro-nano HAp/silk could facilitate osteogenesis and angiogenesis. All the outcomes hint that Ginsenoside Rb1 could reinforce the osteogenesis differentiation and angiogenesis factor's expression of BMSCs. Moreover, micro-nano HAp combined with silk could act as a carrier for Ginsenoside Rb1 to repair bone defect.

Tracing the origin of wrist-ankle acupuncture based on / 中国针灸

The origin and basis of wrist-ankle acupuncture were discussed based on the theory of

Discussion on the body conception of the medical scholars at the early eras based on the description of meridians in bamboo slip and silk medical books / 中国针灸

In the paper, the basic situation and description of meridians are introduced on

Esculent coating of spider silk enhanced the preservation and shelf life of apricot / A cobertura escamada de seda de aranha aumentou a preservação e a vida útil do damasco

Abstract According to the Food and Agriculture Organization (FAO), roughly one-third of the total food produced is lost globally. The major cause of this wastage is the perishability of fruits and vegetables. Therefore, researchers have endeavored to develop an effective preservation technique. Our study explored the potential application of spider silk as an odourless and edible preservative coating for fruits. The spider silk was collected from spiders reared in the laboratory, following by degumming and dissolution to formulate the silk solution. For this study, apricots were selected as the model fruit. The apricots were dip coated with the formulated silk solution and allowed to dry. In order to enhance the beta sheet content of the silk coating, the fruits were exposed to water annealing for varying intervals of time under vacuum condition. The effect of silk coating and water annealing time period on preservation of fruits was then evaluated morphologically and gravimetrically. The results showed that the fruits, which were used as control, exhibited a greater degree of water loss and suffered from fungal attack. In contrast, the silk coated fruits showed less water loss and were protected from fungal attack. Therefore, the study provides compelling evidence regarding the application of spider silk as a preservative coating.

Resumo Segundo a Organização para Alimentação e Agricultura (FAO), cerca de um terço do total de alimentos produzidos é perdido globalmente. A principal causa deste desperdício é a perecibilidade das frutas e legumes. Portanto, os pesquisadores têm se esforçado para desenvolver uma técnica de preservação eficaz. Nosso estudo explorou a potencial aplicação de seda de aranha como um revestimento conservante inodoro e comestível para frutas. A seda da aranha foi coletada de aranhas criadas em laboratório, seguindo-se a degomagem e dissolução para formular a solução de seda. Para este estudo, os damascos foram selecionados como fruto modelo. Os damascos foram revestidos por imersão com a solução de seda formulada e deixados secar. A fim de aumentar o teor de folhas beta do revestimento de seda, os frutos foram expostos a recozimento de água durante vários intervalos de tempo sob condições de vácuo. O efeito do tempo de recobrimento de seda e recozimento de água na preservação de frutos foi então avaliado morfologicamente e gravimetricamente. Os resultados mostraram que os frutos, utilizados como controle, apresentaram maior grau de perda de água e sofreram ataque fúngico. Em contraste, os frutos revestidos de seda mostraram menos perda de água e foram protegidos contra ataques fúngicos. Portanto, o estudo fornece evidências convincentes sobre a aplicação de seda de aranha como um revestimento conservante.

Comparing intra-oral wound healing after alveoloplasty using silk sutures and n-butyl-2-cyanoacrylate

OBJECTIVES: The need for proper wound closure is of paramount importance after any intra-oral surgery. Various wound closure techniques have been described in literature using traditional non-absorbable suture materials. These include like synthetic absorbable sutures, surgical staples and tissue adhesives. Cyanoacrylates are among the most commonly used biocompatible tissue adhesives. To evaluate and compare intraoral wound healing using 3-0 silk sutures and n-butyl-2-cyanoacrylate after alveoloplasty.MATERIALS AND METHODS: A total of 20 patients requiring bilateral alveoloplasty in the same arch (upper or lower) were included in this study. Patients with any pre-existing pathology or systemic disease were excluded. After alveoloplasty was performed, the wound was closed using 3-0 braided silk sutures on one side, and using n-butyl-2-cyanoacrylate bio adhesive on the other side. Patients were evaluated based on the following parameters: time required to achieve wound closure; the incidence of immediate and postoperative hemostasis; the time to the use of the first rescue medication; the side where pain first arises; and the side where wound healing begins first.RESULTS: Compared to 3-0 silk sutures, cyanoacrylate demonstrated better hemostatic properties, reduced operative time, reduced postoperative pain and better wound healing.CONCLUSION: These data suggest that cyanoacrylate glue is an adequate alternative to conventional sutures to close the surgical wound after alveoloplasty, and better than are 3-0 silk sutures.

The action of sericin protein on initial nerve repair, associated or not with swimming in wistar rats / Ação da proteína sericina no reparo nervoso inicial, associada ou não à natação, em ratos wistar / Acción de la proteína sericina en la reparación nerviosa inicial, asociada o no a la natación, en ratones wistar

ABSTRACT Objective: To analyze the effects of sericin treatment, associated or not with swimming with load exercise, on initial sciatic nerve repair after compression in Wistar rats. Methods: Forty animals were divided into five groups: control, injury, injury-sericin, injury-swimming and injury-sericin-swimming. During the axonotmesis procedure, the sericin was applied to the injury-sericin and injury-sericin-swimming groups. The injury-swimming and injury-sericin-swimming groups performed the swimming with load exercise for five days, beginning on the third postoperative day (PO), and were evaluated for function, nociception and allodynia. Euthanasia was performed on the 8th PO day and fragments of the nerve were collected and prepared for quantitative and descriptive analysis in relation to the total amount of viable nerve fibers and non-viable nerve fibers, nerve fiber diameter, axon diameter and myelin sheath thickness. Results: There was no significant improvement in the sciatic functional index up to the eighth day. The Von Frey test of the surgical scar and plantar fascia indicated a reduction in pain and allodynia for the injury-swimming and injury-sericin-swimming groups. The morphological analysis presented similar characteristics in the injury-sericin, injury-swimming and injury-sericin-swimming groups, but there was a significant difference in the number of smaller non-viable nerve fibers in the injury-swimming and injury-sericin-swimming groups as compared to the others. Conclusions: Isolated sericin protein presented proinflammatory characteristics. There was improvement of allodynia and a decrease in the pain at the site of the surgical incision, possibly linked to an aquatic effect. There was no acceleration of nerve repair on the eighth day after the injury. Level of Evidence I; High quality randomized clinical trial with or without statistically significant difference, but with narrow confidence intervals.

RESUMO Objetivo: Analisar os efeitos do tratamento da sericina, associada ou não ao exercício de natação com sobrecarga, sobre o reparo inicial do nervo isquiático após compressão em ratos Wistar. Métodos: Foram separados 40 animais em cinco grupos, sendo eles: controle; lesão; lesão-sericina; lesão-natação e lesão-sericina-natação. Durante o procedimento de axonotmese, a sericina foi aplicada sobre a lesão nos grupos lesão-sericina e lesão-sericina-natação. Os grupos lesão-natação e lesão-sericina-natação realizaram o exercício de natação com sobrecarga durante cinco dias, iniciando no terceiro dia pós-operatório (PO), sendo avaliados quanto à função, nocicepção e alodinia. A eutanásia foi realizada no oitavo dia PO, sendo que dois fragmentos do nervo foram coletados e preparados para análise quantitativa e descritiva em relação a quantidade total de fibras nervosas viáveis, não viáveis, diâmetro da fibra nervosa, do axônio e espessura da bainha de mielina. Resultados: No índice funcional isquiático não houve melhora significativa até o oitavo dia. O teste de Von Frey na cicatriz cirúrgica e fáscia plantar indicaram redução do quadro álgico e alodinia para os grupos lesão-natação e lesão-sericina-natação. A análise morfológica apresentou características semelhantes nos grupos lesão-sericina, lesão-natação e lesão-sericina-natação, porém houve diferença significativa das fibras nervosas não viáveis menores nos grupos lesão-natação e lesão-sericina-natação em relação aos demais. Conclusões: A proteína sericina isolada apresentou características pró-inflamatórias. Houve melhora da alodinia e diminuição do quadro álgico no local da incisão cirúrgica relacionadas a possível efeito aquático. Não houve aceleração do reparo nervoso no oitavo dia após a lesão. Nível de Evidência I; Estudo clínico randomizado de alta qualidade com ou sem diferença estatisticamente significante, mas com intervalos de confiança estreitos.

RESUMEN Objetivo: Analizar los efectos del tratamiento de la sericina, asociada o no al ejercicio de natación con sobrecarga, sobre la reparación inicial del nervio isquiático después de compresión, en ratones Wistar. Métodos: Se separaron 40 animales en cinco grupos, siendo: control; lesión; lesión-sericina; lesión-natación y lesión-sericina-natación. Durante el procedimiento de axonotmesis, la sericina fue aplicada sobre la lesión en los grupos lesión-sericina y lesión-sericina-natación. Los grupos lesión-natación y lesión-sericina-natación realizaron el ejercicio de natación con sobrecarga durante cinco días, iniciándose en el tercer día postoperatorio (PO), siendo evaluados cuanto a la función, nocicepción y alodinia. La eutanasia fue realizada en el octavo día PO, siendo que dos fragmentos del nervio fueron recolectados y preparados para análisis cuantitativo y descriptivo, con relación a la cantidad total de fibras nerviosas viables, no viables, diámetro de la fibra nerviosa, del axón y espesor de la vaina de mielina. Resultados: En el índice funcional isquiático no hubo mejoría significativa hasta el octavo día. La prueba de "Von Frey" en la cicatriz quirúrgica y la fascia plantar indicaron reducción del cuadro álgico y alodinia, para los grupos lesión-natación y lesión-sericina-natación. El análisis morfológico presentó características similares en los grupos lesión-sericina, lesión-natación y lesión-sericina-natación, pero hubo diferencia significativa de las fibras nerviosas no viables menores en los grupos lesión-natación y lesión-sericina-natación con relación a los demás. Conclusiones: La proteína sericina aislada presentó características proinflamatorias. Hubo mejora de la alodinia y disminución del cuadro álgico en el lugar de la incisión quirúrgica, relacionadas al posible efecto acuático. No hubo aceleración de la reparación nerviosa en el octavo día después de la lesión. Nivel de Evidencia I; Ensayo clínico aleatorizado de alta calidad con o sin diferencia estadísticamente significativa, pero con intervalos de confianza estrechos.

Adhesión Bacteriana en Hilo de Sutura de Seda Negra y Nylon Post Extracción Dental Simple: Ensayo Clínico Controlado / Bacterial Adhesion in Black Silk Suture Thread and Nylon Post Simple Dental Extraction: Controlled Clinical Trial

RESUMEN: El objetivo de este estudio fue comparar los hilos de sutura de seda negra y la sutura nylon con respecto a la adhesión bacteriana post extracción dental simple de piezas posteriores. El presente trabajo se desarrolló en la Clínica Odontológica y el Laboratorio de Microbiología de la Unidad de Ciencias Biomédicas y Biotecnología de la Universidad Privada Antenor Orrego (Trujillo, Perú), entre agosto y setiembre de 2014. Se trabajó con 19 unidades de muestreo para hilo de seda negra y 19 para nylon. El procedimiento de exodoncia para todos los pacientes fue estandarizado. Luego de la extracción, se procedió a suturar la herida quirúrgica, colocando dos puntos circunferenciales, uno con cada tipo de hilo. A los 7 días, los hilos fueron retirados y sometidos a análisis microbiológico. La adhesión bacteriana de los hilos de sutura seda negra y nylon fue comparada empleando el test de Wilcoxon. Además la adhesión bacteriana de cada hilo fue comparada con la adhesión en hilos estériles (control) empleando el test de Mann-Whitney para una p<0,005. Al comparar la adhesión bacteriana de ambos hilos, se encontró diferencia entre ellos (p=0,027), correspondiendo mayor adhesión al hilo de nylon. La adhesión bacteriana fue mayor en el hilo de sutura de nylon comparado con el hilo de sutura de seda negra.

ABSTRACT: The objective of the study was to compare black silk suture threads and nylon suture with respect to bacterial adhesion after simple dental extraction of posterior pieces. The present study was developed in the Clínica Estomatológica and the Laboratorio de Microbiología of the Unidad de Ciencias Biomédicas y Biotecnología de la Universidad Privada Antenor Orrego (Trujillo, Peru), between August and September 2014. We worked with 19 units sampling for black silk thread and 19 for nylon. The procedure of exodontia for all patients was standardized. After the extraction, the surgical wound was sutured, placing two circumferential points, one with each type of thread. After 7 days, the threads were removed and subjected to microbiological analysis. The bacterial adhesion of the black silk and nylon suture strands was compared using the Wilcoxon test. In addition, the bacterial adhesion of each strand was compared with the adhesion in sterile strands (control) using the Mann-Whitney test for p <0.005. When comparing the bacterial adhesion of both threads, a difference was found between them (p = 0.027), corresponding greater adhesion to the nylon thread. Bacterial adhesion was higher in nylon suture compared to black silk suture.

Carbon-Fiber Based Microelectrode Array Embedded with a Biodegradable Silk Support for In Vivo Neural Recording

BACKGROUND: Recently, carbon fibers have been utilized to develop a depth-type microelectrode array for chronic neural recording. Since the diameter of carbon fibers is smaller than the conventional electrodes made of metal wires or microfabricated silicon, the carbon fiber electrodes showed an improved capability for chronic neural recording with less tissue damages. However, the carbon fiber based microelectrodes have a limitation of short insertion depth due to a low stiffness. METHODS: We proposed a carbon fiber based microelectrode array embedded with a mechanical support structure to facilitate the penetration into the deeper brain. The support is made of biodegradable silk fibroin to reduce the reactive tissue responses. The 4-channel carbon fiber based microelectrode arrays were fabricated and accessed in terms of electrochemical impedance, recording capability for 1-month implantation in rat hippocampi. The electrodes with tungsten supports were fabricated and tested as a control group. Immunohistochemical analysis was performed to identify the reactive glial responses. RESULTS: The carbon fiber based electrode arrays with silk supports showed about 2-fold impedance increase 2 weeks after implantation while the number of active electrodes decreased simultaneously. However, after 1 month, the electrode impedance decreased back to its initial value and the percentage of active electrodes also increased above 70%. Immunohistochemical staining clearly showed that the electrodes with silk supports induced less reactive glial responses than that with tungsten supports. CONCLUSION: The proposed carbon fiber based microelectrode array is expected to be used for long-term in vivo neural recording from deep brain regions with the minimized reactive tissue response.

Enhanced Antioxidant and Anticancer Properties of Processed Eucommiae Cortex

Eucommiae Cortex (EC), bark of Eucommia ulmoides, has been known as a traditional medicine to regulate hypertension and immune system. Because silk of gum in the EC blocks the release of active ingredients, EC generally has been utilized after processing with carbonization or salt-water to breakdown it. This study aimed to investigate the differences of non-processed EC and processed EC on antioxidant and anticancer properties. Antioxidant capacity was assessed by measuring the content of total polyphenols, reducing power, and ABTS radical scavenging effect. And anticancer effects were examined by evaluating the viability of pancreatic cancer cells and wound healing ability. The results demonstrated that processed EC contained more content of polyphenols and exhibited more potent reducing power and radical scavenging effect than non-processed EC. In addition, processed EC more efficiently inhibited proliferation and migration of pancreatic cancer cells. These results suggest that processing of medicinal plants can improve the biological properties such as antioxidant or anticancer activity, which may lead to the development of herbal medicine treatment technology.

Analysis of protective mechanism of silk protein based cryoprotectants / 生物医学工程学杂志

Dimethyl sulfoxide (Me SO) supplemented with fetal bovine serum (FBS) is a widely used cryoprotectant combination. However, high concentration of Me SO is toxic to cells, and FBS presents problems related to diseases such as bovine spongiform encephalopathy and viral infections. Silk protein is a kind of natural macromolecule fiber protein with good biocompatibility and hydrophilicity. The aim of this paper is to analyze the cryoprotective mechanism of silk protein as cryoprotectant. Firstly, differential scanning calorimetry (DSC) was used to measure the thermal hysteresis activity (THA) of silk protein. The THA of 10 mg/mL sericin protein was 0.96°C, and the THA of 10% (V/V) fibroin protein was 1.15°C. Then the ice recrystallization inhibition (IRI) of silk protein-PBS solution was observed with cryomicroscope. The cold stage was set at - 7°C, after 40 minutes' incubation, the mean grain size rate (MGSR) of sericin protein and fibroin protein were 28.99% and 3.18%, respectively, which were calculated relative to phosphate buffer saline (PBS) control. It is indicated that sericin and silk fibroin have certain effects of inhibiting recrystallization of ice crystals. Finally, the structure and physicochemical properties of silk protein were analyzed by Fourier transform infrared spectroscopy (FTIR). The results showed that the content of the random coil was 75.62% and the β-sheet structure was 24.38% in the secondary of sericin protein. The content of the β-sheet structure was 56.68%, followed by random coil structure 22.38%, and α-helix 16.84% in the secondary of fibroin protein. The above analysis demonstrates the feasibility of silk fibroin as a cryoprotectant, and provides a new idea for the selection of cryoprotectants in the future.

The Effect of Saccharin on the Gene Expression of NF-κB and Inflammatory Cytokines in LPS-Stimulated SW480 Colon Cancer Cells

There have been no published studies concerning the anti-inflammatory effects of corn silk on colon cancer cells. Thus, this study was conducted to investigate the effect of corn silk extract containing high levels of maysin on inflammation and its mechanism of action in colon cancer cells. SW 480 human colon cancer cells were treated with 1 µg/mL of lipopolysaccharide (LPS) to induce inflammation, and next they were treated with different concentrations of corn silk extract (0, 5, 10 and 15 µg/mL). The concentrations of nitric oxide (NO) were determined. The mRNA expressions of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), tumor necrosis factor α (TNF-α), interleukin-1beta (IL-1β) and interleukin-6 (IL-6), were determined. Western blot analysis was performed to determine the protein expressions of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases, and the latter consists of extracellular signal-related kinase (ERK), c-jun NH2-terminal kinase (JNK) and p38 MAP kinase (p38). The concentration of NO and the mRNA expression of iNOS were significantly and dose-dependently decreased in the corn silk-treated groups (P<0.05). The mRNA expression of TNF-α, IL-1β and IL-6 were significantly increased in the LPS-treated group (P<0.05), but these expressions were significantly and dose-dependently decreased in the corn silk treated groups (P<0.05). The protein expressions of NF-κB (in a dose-dependent fashion), ERK (at 10 and 15 µg/mL), JNK (at 15 µg/mL) and p38 (at 10 and 15 µg/mL) were significantly decreased with corn silk treatments (P<0.05). In conclusion, corn silk extract containing high levels of maysin seems to inhibit the LPS-induced inflammatory responses in SW480 colon cancer cells via the NF-κB pathway.

Study on the mechanical properties of sutures in the process of suturing / 生物医学工程学杂志

Suture broken, knot slipping and tissue tearing are the main reasons of wound closure failure in clinical operation. Based on this, we simulated the suturing and healing operation by using a biological materials testing machine and investigated the tensile properties before and after knotting, relaxation property and friction property of three common sutures: silk, polyglactin 910 and polypropylene. Results show that the tensile property decreased after knotting. The tensile strength of polyglactin 910 and elongation of polypropylene were the largest. During the relaxation process, the sutures relaxed the most in the first 2 hours. The relaxation from less to more was: polyglactin 910, silk and polypropylene. Coating or monofilament could obviously reduce the surface roughness of sutures, and thus reduce the friction force of the suture-suture interface. The friction force of the suture-suture interface increased with the increasing load but did no change with the increasing velocity. The results can provide an important theoretical basis for the optimizations of suture design and knotting operation.

Functionalized genetic engineered silk-based biomaterials and their applications / 生物工程学报

Silk-based biomaterials are featured with excellent mechanical properties, good biocompatibility and biodegradability, which contribute to their potential applications in biomedical field. The current recognition of silk protein materials in structure and function provides a basic theory for the transformation of silk protein into new types of biomaterials. In addition, exogenous sequences encoding new peptide or structural domain can be inserted into the maternal gene sequences encoding silk proteins through genetic engineering technology to synthesize novel silk-based biomaterials with unique functions. This review summarizes the current trend and development perspective of genetically engineered functional silk-based materials for biomedical applications.

Effect of Garcinia mangostana L. and propolis extracts on the inhibition of inflammation and alveolar bone loss in ligature-induced periodontitis in rats

The purpose of this study was to evaluate the effect of mangosteen extract complex (MEC; Garcinia mangostana L. and propolis extracts) on the inhibition of inflammation and prevention of alveolar bone loss using a ligature-induced periodontitis model. Rat molars were ligatured with silk, and 1 µg/mL of lipopolysaccharide of Porphyromonas gingivalis was injected into the buccal and palatal gingivae of the teeth with or without treatment with the MEC. Changes in the expression levels of prostaglandin E₂ (PGE₂), interleukin-8 (IL-8), inducible nitric oxide synthase (iNOS), matrix metalloproteinase-8 (MMP-8), cyclooxygenase (COX)-1, and COX-2 in gingival tissues were evaluated using enzyme-linked immunosorbent assays. Alveolar bone loss around the ligated molars was examined using micro-computed tomography. The expression levels of PGE₂, IL-8, iNOS, MMP-8, COX-1, and COX-2 in gingival tissues were significantly reduced in the group treated with a mixture of 16 µg of mangosteen extract powder and 544 µg of propolis extract powder (ligation [Lig] + lipopolysaccharide extracted from P. gingivalis KCOM 2804 [L] + MEC 1:34). Additionally, alveolar bone loss was significantly reduced in the Lig + L + MEC 1:34 group compared with that in other groups. These results indicate that the MEC could be useful in preventing and treating periodontitis.

Oral Administration of Silk Peptide Enhances the Maturation and Cytolytic Activity of Natural Killer Cells

Silk peptide, the hydrolysate of silk protein derived from cocoons, has been employed as a biomedical material and is believed to be safe for human use. Silk peptide display various bioactivities, including anti-inflammatory, immune-regulatory, anti-tumor, anti-viral, and anti-bacterial. Although earlier investigations demonstrated that silk peptide stimulates macrophages and the production of pro-inflammatory cytokines, its effect on natural killer (NK) cell function has not yet been explored. In this study, we initially confirmed that silk peptide enhances NK cell activity in vitro and ex vivo. To assess the modulatory activity of silk peptide on NK cells, mice were fed various amounts of a silk peptide-supplemented diet for 2 months and the effects on immune stimulation, including NK cell activation, were evaluated. Oral administration of silk peptide significantly enhanced the proliferation of mitogen- or IL-2-stimulated splenocytes. In addition, oral silk peptide treatment enhanced the frequency and degree of maturation of NK cells in splenocytes. The same treatment also significantly enhanced the target cell cytolytic activity of NK cells, which was determined by cell surface CD107a expression and intracellular interferon-γ expression. Finally, oral administration of silk peptide stimulated T helper 1-type cytokine expression from splenic lymphocytes. Collectively, our results suggest that silk peptide potentiates NK cell activity in vivo and could be used as a compound for immune-modulating anti-tumor treatment.

Comparison between rubber band and ethelon suture as a cutting seton in perianal fistula

Background: Fistula-in-ano is a commonly encountered surgical problem. There is a risk of sphincter muscle damage during fistulectomy. Seton suture is used to decrease this risk. Different types of Setons are used for this purpose

Aim: To compare 2 types of cutting Seton as regard Postoperative pain, duration until Seton cut through, post operative faecal incontinence and recurrence

Methods: This study was conducted on 80 patients in 2 groups with high perianal fistula or low perianal fistula associate with abscess cavity. Patients with inflammatory bowel disease, history of malignancy, and previous recto-anal operations were excluded from this study. One group with insertion of sterilized rubber band and silk suture was applied at the anal verge the other with Ethilon sutures. Follow up and tightening of the seton done as outpatient

Results: About half [46.25%] had low perianal fistulas with abscess cavity, and 53.75% had high perianal fistulas. Group [A] patients had 10% wound infection and group [B] had 5%, all responded to conservative management. The mean VAS score of the patients on the 1st day was [3.7 +/- 1.14], and [2.85 +/- 0.92] and on the 7th day was [1.28 +/- 0.85] and [0.88 +/- 0.88] respectively. Seton fell down after a mean time [26.35 days +/- 5.12 days] in group [A] and [27.65 days +/- 6.84 days] in group [B]. Complete healing was achieved in 77.5% of group [A] and in 60 % of group [B] after 1 month and 40 patients [100%] in both groups at 3 months. 7.5% of recurrence in group [A] and 2.5% case of recurrence in group [B]

Conclusion: Rubber band Seton is easy and cheap and provide slow and steady cutting of the sphincter maintaining continence

Preparation and characterization of oriented scaffolds derived from cartilage extracellular matrix and silk fibroin / 华西口腔医学杂志

OBJECTIVE@#This study aims to prepare oriented scaffolds derived from a cartilage extracellular matrix (CECM) and silk fibroin (SF) and use to investigate their physicochemical property in cartilage tissue engineering.@*METHODS@#Oriented SF-CECM scaffolds were prepared from 6% mixed slurry (CECM：SF=1：1) through modified temperature gradient-guided thermal-induced phase separation, followed by freeze drying. The SF-CECM scaffolds were evaluated by scanning electron microscopy (SEM) and histological staining analyses and determination of porosity, water absorption, and compressive elastic modulus of the materials.@*RESULTS@#The SEM image showed that the SF-CECM scaffolds contained homogeneous reticular porous structures in the cross-section and vertical tubular structures in the longitudinal sections. Histological staining showed that cells were completely removed, and the hybrid scaffolds retained proteogly can and collagen. The composition of the scaffold was similar to that of natural cartilage. The porosity, water absorption rate, and vertical compressive elastic modulus of the scaffolds were 95.733%±1.010%, 94.309%±1.302%, and (65.40±4.09) kPa, respectively.@*CONCLUSIONS@#The fabricated SF-CECM scaffolds exhibit satisfactory physicochemical and biomechanical properties and thus could be an ideal scaffold in cartilage tissue engineering.