RESUMEN
BACKGROUND:Cartilage defects are one of the major clinical challenges faced by orthopedic surgeons.Tissue engineering is an interdisciplinary approach that combines knowledge of engineering and cell biology to provide new ideas and approaches for the repair of cartilage defects. OBJECTIVE:To prepare a multi-component composite scaffold based on silk fibroin,gelatin,and chitosan to screen for a three-dimensional porous scaffold suitable for cartilage regeneration by evaluating its physicochemical properties and biological performance. METHODS:Four groups of porous scaffolds were prepared by vacuum freeze-drying method using silk fibroin,gelatin and chitosan as the base materials,namely chitosan/gelatin scaffold,silk fibroin/chitosan scaffold,silk fibroin/gelatin scaffold and silk fibroin/chitosan/gelatin scaffold.The suitable cartilage scaffolds were screened by scanning electron microscopy,X-ray diffractometer,porosity,water absorption and swelling rate,biodegradation rate and mechanical property detection.Then cartilage scaffolds were co-cultured with chondrocytes isolated and extracted from patients with osteoarthritis.The feasibility of porous scaffolds for cartilage injury repair was evaluated in vitro by cell adhesion rate assay,cell live-dead staining and cell activity proliferation assay. RESULTS AND CONCLUSION:(1)All four groups of scaffolds had porous structures.The comprehensive physical performance test results showed that the silk fibroin/gelatin/chitosan scaffold was more in line with the requirements of cartilage defect repair.This scaffold had a pore size of(176.00±53.68)μm,the porosity of(80.15±2.57)%,and water absorption and swelling rate of(3 712±358)%.After immersion in PBS containing lysozyme for 28 days in vitro,the biodegradation rate was(46.87±3.25)%,and it had good mechanical properties.(2)Chondrocytes could adhere well on the silk fibroin/gelatin/chitosan scaffold,and the cell adhesion rate increased with time.CCK8 and live/dead cell double staining results showed that silk fibroin/gelatin/chitosan scaffold had good biocompatibility and low cytotoxicity.(3)The results showed that silk fibroin/gelatin/chitosan scaffold had a highly hydrated 3D structure,suitable pore size and porosity,good biodegradability and superior mechanical properties,which can provide a good reticular skeleton and microenvironment for nutrient transport and chondrocyte attachment and proliferation.
RESUMEN
BACKGROUND:In the construction of guided bone regeneration membrane with biological function,a single material cannot meet the clinical needs due to its insufficient function,so the composite of multiple materials has become a trend of tissue repair engineering. OBJECTIVE:To prepare silk fibroin/bioactive glass composite fiber membranes by electrospinning technology,and to characterize the physicochemical properties and biocompatibility in vitro. METHODS:The solution of electrospinning was prepared by dissolving 0.8 g silk fibroin protein in 10 mL hexafluoro-isopropanol alcohol,and the nanofiber membrane of silk fibroin protein was prepared by electrospinning technology(denoted as SF fiber membrane).0.1,0.3,0.5,and 0.8 g of bioactive glass were added to the electrospinning solution,and the silk fibroin/bioactive glass composite fiber membrane was prepared by electrospinning technology(recorded as SF/1BG,SF/3BG,SF/5BG,and SF/8BG fiber membrane in turn).The physicochemical properties and biocompatibility of five groups of fiber membranes were characterized. RESULTS AND CONCLUSION:(1)The scanning electron microscopy results showed that nanofibers of the prepared composite membrane were smooth,continuous and uniform and had no beaded structure.There was no obvious adhesion between the silk fibers,and they all showed random arrangement of disordered porous structures.The fiber diameter of the fiber membrane decreased after the addition of bioactive glass.Fourier infrared spectroscopy and X-ray diffraction detection results showed that the chemical structure of silk fibroin protein and bioactive glass in fiber membrane was stable.The water contact angles of SF,SF/1BG,SF/3BG,SF/5BG,and SF/8BG were 105.02°,72.58°,78.13°,79.35°,and 72.50°,respectively.(2)Bone marrow mesenchymal stem cells were inoculated on five groups of fiber membranes.CCK-8 assay results showed that SF/1BG,SF/3BG,and SF/5BG fiber membranes could promote the proliferation of bone marrow mesenchymal stem cells compared with SF and SF/8BG.Live cell/dead cell staining showed that the cell vitality on the surface of the five groups of fiber membranes was better,and the number and distribution of cells on the surface of SF/5BG fiber membrane were more uniform.Rhodamine phalloidin staining and scanning electron microscopy exhibited that compared with SF fiber membrane,the SF/5BG fiber membrane was more favorable to the adhesion of bone marrow mesenchymal stem cells.Bone marrow mesenchymal stem cells were inoculated on the fiber membrane of the five groups for osteogenic induction differentiation,and the alkaline phosphatase activity of the SF/3BG and SF/5BG groups was higher than that of the other three groups(P＜0.05,P＜0.01,P＜0.001).Alizarin red staining showed that the formation of calcium nodules in fiber membrane increased after the addition of bioactive glass,and the formation of calcium nodules in the SF/5BG group was the most.(3)The results show that silk fibroin/bioactive glass composite fiber membrane has good biosafety and biocompatibility.
RESUMEN
BACKGROUND:Microglia cells play a major role in maintaining the balance as well as the development and function reconstruction of the central nervous system.As a histone deacetylase inhibitor,Scriptaid can inhibit neuroinflammation and enhance neuroprotection. OBJECTIVE:To investigate the effect of silk fibroin methacryloyl hydrogel loaded with Scriptaid on the behaviors of microglia cells. METHODS:Microglia(BV2 cells)were cultured in medium containing different concentrations of Scriptaid(0,0.1,0.5,1,2,5,10 μmol/L).The optimal concentration of Scriptaid was screened by the CCK-8 assay and live/dead cell staining.Silk fibroin methacryloyl hydrogels loaded with or without Scriptaid were prepared using photocuring.The micromorphology,swelling properties,mechanical properties,slow release properties,and hydrophilicity of the hydrogels were characterized.Microglia(BV2 cells)were inoculated in the subventricular region of 24-well Transwell and cultured in five groups.In the control group,the cell culture medium was added to the lower chamber.In the lipopolysaccharide group,Scriptaid group,hydrogel group,and drug-loaded hydrogel group,cell culture media containing lipopolysaccharide were added into the lower chamber.After 24 hours of lipopolysaccharide intervention,in the Scriptaid group,hydrogel group and drug-loaded hydrogel group,Scriptaid,silk fibroin methacryloyl hydrogel,and silk fibroin methacryloyl hydrogel loaded with Scriptaid were added to the upper chamber,respectively.The culture medium was replaced with ordinary culture medium and continued to culture for 24 hours.The cell viability was detected by CCK-8 assay,and the cell phenotype was detected by immunofluorescence staining of induced nitric oxide synthase and arginase 1. RESULTS AND CONCLUSION:(1)Compared with the group without Scriptaid,the viability and number of BV2 cells were decreased after Scriptaid added.When Scriptaid 2 μmol/L or above was added,the cell viability was lower than the standardized cell viability(70%),and the number of BV2 cells was significantly reduced.Therefore,1 μmol/L Scriptaid was selected to be loaded into the hydrogel.(2)Characterization experiments showed that the addition of Scriptaid did not affect the microscopic morphology,swelling rate of water absorption,compression modulus and hydrophilicity of silk fibroin methacryloyl hydrogel,and silk fibroin methacryloyl hydrogel had slow release performance.(3)The result of CCK-8 assay showed that compared with the control group,silk fibroin methacryloyl hydrogel significantly increased the viability of BV2 cells(P<0.001).(4)Immunofluorescence staining showed that compared with the control group,the expression of inducible nitric oxide synthase was increased in the lipopolysaccharide group(P<0.01);the expression of inducible nitric oxide synthase was decreased(P<0.01)and the expression of arginase 1 was increased(P<0.001)in the drug-loaded hydrogel group;the expression of arginase 1 was increased in the Scriptaid group(P<0.01).(5)The results indicate that Scriptaid-loaded silk fibroin methacryloyl hydrogel is able to promote polarization of microglia to the M2 type after lipopolysaccharide induction.
RESUMEN
Objective @#To develop a high modulus and high strength biodegradable silk fibroin GBR membrane to address the issue of maintaining the space for bone regeneration in the repair of osseous defects . @*Methods @#After purifying silk fibroin protein , membrane materials were prepared using evaporation-hot pressing method . The physi- cal and chemical properties and biological performance of the membranes were evaluated using stretching tests , in vitro simulations , and cell co-culturing methods . @*Results @#A silk fibroin GBR membrane was successfully fabrica- ted , resulting in a simulated degradation rate of 35 . 3% after 12 h in vitro . The wet-state elastic modulus reached 45 MPa , while the tensile strength reached 8. 39 MPa. Furthermore , the cell survival rate was nearly 100% after 7 days . @*Conclusion @#The biodegradable GBR membrane produced in this study possesses high modulus and strength , as well as excellent biocompatibility , offering a promise as a foundation for addressing the bone defect re- pair and bone space maintenance .
RESUMEN
To understand the current quality status and rearing situation of Bombyx Batryticatus, the authors collected 102 batches of Bombyx Batryticatus from different main producing areas and five major Chinese medicine markets from 2016 to 2018, and measured the properties and quality of the silk gland, to clarify the quality status of Bombyx Batryticatus from different producing areas and markets. In addition, 35 batches of Bombyx Batryticatus from 2019 to 2022 were used to verify the silk gland after revision. Moreover, Beauveria Bassiana was inoculated in the silkworm of 4-5 instars, and standardized rearing was carried out until they die. The death rate and the quality of Bombyx Batryticatus were measured to determine the differences in Bombyx Batryticatus of different instars, and explore the rationality of the infection age of Bombyx Batryticatus in Chinese Pharmacopoeia(2020). The results revealed that in the 102 batches of Bombyx Batryticatus, the qualification rate of silk gland was low; the content of total ash far exceeded the standard; the content of beauvericin varied greatly. The qualification rate of the silk gland of the 35 batches of Bombyx Batryticatus was only 47.49%, which could be increased to 73.00% if the number of silk gland was 2 to 4. The death rate of Bombyx Batryticatus at different infection ages was quite different, with uneven quality. Generally, the yield of Bombyx Batryticatus inoculated on the first day of the fifth instar was high with good quality. Therefore, in combination with the quality and actual production of Bombyx Batryticatus, the following suggestions were proposed for revision of Bombyx Batryticatus in Chinese Pharmacopoeia(2025): The number of silk gland should be revised as 2-4 bright brown or bright black silk glands, after which, the quality of Bombyx Batryticatus could be guaranteed, and the "quality identification based on character" could also be reflected scientifically; the content determination index that the content of beauvericin shall not be less than 0.017% should be added to better control the quality of Bombyx Batryticatus; the infection age should be revised as the first day of the fifth instar to narrow the age span, which could better fit the actual production and ensure the quality of Bombyx Batryticatus.
Asunto(s)
Animales , Bombyx , Medicina Tradicional de Asia Oriental , Seda , LarvaRESUMEN
OBJECTIVE To prepare spider fibroin membrane loaded with Periplaneta americana extract， and investigate its characterization， in vitro drug release property and cytotoxicity. METHODS Using natural spider silk collected from Chilobrachys guangxiensis as raw material， P. americana extract as model drug， the drug-loaded spider fibroin membrane （hereinafter referred to as drug-loaded membrane） was prepared by solvent casting method. The material matrix spider fibroin membrane without P. americana extract （hereinafter referred to as blank membrane） was prepared with same method. The membrane structure was characterized by static water contact angle， Fourier infrared chromatography， X-ray diffraction and scanning electron microscopy from different angles； drug release characteristics in artificial saliva were simulated in vitro to evaluate the drug sustained-release performance. MTT assay was adopted to validate the cytotoxicity of drug-loaded membrane. RESULTS The drug-loaded membrane was prepared， and the static water contact angle was less than 90°， which was less than that of blank membrane. The drug-loaded membrane showed the characteristic absorption peak to polypeptide of P. americana extract at 1 500-1 700 cm－1. X-ray diffraction and scanning electron microscopy also proved that the drug was successfully loaded into the pellicle. The release time of the pellicle in artificial saliva was more than 200 min. The MTT test results showed that the cell proliferation rates of blank membrane and drug-loaded membrane were 84.6% and 79.4% （both greater than 70%）， respectively， without significant potential cytotoxicity. CONCLUSIONS Drug-loaded membrane prepared with natural spider silk has a certain sustained-release effect in artificial saliva， which can be further developed as a drug sustained-release carrier with excellent biological characteristics and biocompatibility.
RESUMEN
Silk fibroin (SF) as a natural biopolymer has become a popular material for biomedical applications due to its minimal immunogenicity, tunable biodegradability, and high biocompatibility. Nowadays, various techniques have been developed for the applications of SF in bioengineering. Most of the literature reviews focus on the SF-based biomaterials and their different forms of applications such as films, hydrogels, and scaffolds. SF is also valuable as a coating on other substrate materials for biomedicine; however, there are few reviews related to SF-coated biomaterials. Thus, in this review, we focused on the surface modification of biomaterials using SF coatings, demonstrated their various preparation methods on substrate materials, and introduced the latest procedures. The diverse applications of SF coatings for biomedicine are discussed, including bone, ligament, skin, mucosa, and nerve regeneration, and dental implant surface modification. SF coating is conducive to inducing cell adhesion and migration, promoting hydroxyapatite (HA) deposition and matrix mineralization, and inhibiting the Notch signaling pathway, making it a promising strategy for bone regeneration. In addition, SF-coated composite scaffolds can be considered prospective candidates for ligament regeneration after injury. SF coating has been proven to enhance the mechanical properties of the substrate material, and render integral stability to the dressing material during the regeneration of skin and mucosa. Moreover, SF coating is a potential strategy to accelerate nerve regeneration due to its dielectric properties, mechanical flexibility, and angiogenesis promotion effect. In addition, SF coating is an effective and popular means for dental implant surface modification to promote osteogenesis around implants made of different materials. Thus, this review can be of great benefit for further improvements in SF-coated biomaterials, and will undoubtedly contribute to clinical transformation in the future.
Asunto(s)
Materiales Biocompatibles/química , Seda/química , Fibroínas/farmacología , Implantes Dentales , Osteogénesis , Andamios del Tejido/química , Ingeniería de Tejidos/métodosRESUMEN
Aim To investigate the mechanism of corn silk decoction on diabetic nephropathy (DN) rats using metabolomics technology. Methods DN rat model was established by feeding with high-sugar and high-fat diet, combined with intraperitoneal injection of low dose streptozotocin. Renal organ index, fasting blood glucose, albumin creatinine ratio, serum creatinine, blood urea nitrogen, triglyceride, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol indexes were measured, and the pathological changes of renal tissues were also observed to evaluate the intervention effect of corn silk on DN model rats. Further, UPLC/Q-TOF-MS technology was used to screen potential biomarkers in renal tissues and urine, combined with principal component analysis (PC A) and orthogonal partial least squares discriminant analysis (OPLS-DA). After identification by HM-DB and KEGG database, the biomarkers were imported into MetaboAnalyst for metabolic pathway analysis. Results All indexes and pathological damage of kidneys were improved in groups with different doses of corn silk, indicating that corn silk had a good intervention effect on DN. Metabolomic analysis showed that 18 biomarkers could be significantly called back by corn silk, and it involved 18 metabolic pathways mainly including phenylalanine, tyrosine and tryptophan biosynthesis, riboflavin metabolism, arachidonic acid metabolism, and tyrosine metabolism. Conclusions The mechanism of corn silk decoction intervention on DN may be related to amino acid metabolism, riboflavin metabolism, and arachidonic acid metabolism.
RESUMEN
Growth hormone deficiency (GHD) has become a serious healthcare burden, and presents a huge impact on the physical and mental health of patients. Here, we developed an actively separated microneedle patch (PAA/NaHCO3-Silk MN) based on silk protein for sustained release of recombinant human growth hormone (rhGH). Silk protein, as a friendly carrier material for proteins, could be constructed in mild full-water conditions and ensure the activity of rhGH. After manually pressing PAA/NaHCO3-Silk MN patch to skin for 1 min, active separation is achieved by absorbing the interstitial fluid (ISF) to trigger HCO3 ‒ in the active backing layer to produce carbon dioxide gas (CO2). In rats, the MN patch could maintain the sustained release of rhGH for more than 7 days, and produce similar effects as daily subcutaneous (S.C.) injections of rhGH in promoting height and weight with well tolerated. Moreover, the PAA/NaHCO3-Silk MN patch with the potential of painless self-administration, does not require cold chain transportation and storage possess great economic benefits. Overall, the PAA/NaHCO3-Silk MN patch can significantly improve patient compliance and increase the availability of drugs, meet current unmet clinical needs, improve clinical treatment effects of GHD patients.
RESUMEN
Objective After hydrogen bonding between collagen ( COL) and silk fibroin ( SF ) at different concentrations, a composite scaffold with adjustable stiffness was prepared by combining with gel system, and its physical and chemical properties were characterized. Methods SF with different qualities was dissolved in sodium alginate (SA) solution, then COL solution at different concentration and calcium carbonate ( CaCO3 ) powder were added. The hydrogels of SC1, SC2, and SC3 groups were obtained by taking out the mixed solution and adding some gluconic acid lactone ( GDL) powder, and different SF scaffolds were obtained after freeze drying. Results The SF scaffolds with adjustable stiffness were successfully prepared. The compression moduli of SC1, SC2, and SC3 groups were (17. 31±2. 73), (24. 12±1. 81), (32. 54±1. 81) kPa, respectively. The innerstructure of the scaffolds was observed. From SC1 group to SC3 group, pores of the scaffolds were smaller and fewer, and hydrophilicity of the materials become better and better. Conclusions Three-dimensional ( 3D) porous scaffolds with different matrix stiffness can be prepared by changing the concentration of SF and COL solution. The concentration of SF and COL is proportional to the compression modulus, water absorption, water retention and swelling rate of SF scaffolds, while inversely proportional to porosity. The findings of this study are expected to provide theoretical guidance for construction of scaffolds with appropriate matrix stiffness for inducing osteogenic differentiation of mesenchymal stem cells
RESUMEN
This study aimed to prepare silk fibroin nanoparticles (SF-NPs) and assess the physicochemical properties and biocompatibility of the formulation. An optimized and simplified solvent displacement method was employed to obtain SF-NPs. Single-factor prescription screening, such as silk fibroin (SF) solution concentration, the ratio of SF solution to organic solvent, ultrasonication power and time, and different types of organic phases, was used to optimize the formulation. The characterization of the optimal formulation included particle size, polydispersity index (PDI), zeta potential, morphology, and stability. The in vitro cell compatibility of the nanoparticles was evaluated using CCK-8 and Calcein-AM/PI cell viability staining. The results showed that when SF concentration was 20 mg·mL-1, volume ratio of aqueous phase to acetone was 1∶6, ultrasonic power was 80 W and ultrasonic time was 3 min, the best SF-NPs was obtained. The nanoparticles prepared in this study exhibit a near-spherical shape, with a uniform size distribution, having an average size of 144.8 nm, a PDI of 0.174, and a zeta potential of -27.35 mV. Results from in vitro cell experiments demonstrate excellent cell compatibility of SF-NPs, showing the ability to promote cell proliferation. The SF-NPs which were successfully prepared in this study exhibit uniform particle size and excellent biocompatibility.
RESUMEN
From the perspective of medical archaeology, on the basis of sorting out the relevant archaeological findings, and starting from the diachronic nature of spice exchange, this paper divides the development of ancient Chinese fragrant drugs into the occurrence period (pre Qin), the development period (Qin and Han dynasties), the maturity period (Wei, Jin and Tang dynasties), the prosperity period (Song and Yuan dynasties), and the popularity period (Ming and Qing dynasties). The Silk Road has played a vital role in promoting the exchange of fragrant medicine culture. Since the opening of the Silk Road in the Han Dynasty, fragrant drugs from Southeast Asia, South Asia, Central Asia, and the east coast of the Mediterranean Sea have been imported into China. The exchange of fragrant medicine culture coincides with the development trend of the Silk Road. This kind of exchange has a two-way nature. While foreign fragrant drugs are continuously imported into China, Chinese medical concepts and technologies are also promoted abroad. The impact of the exchange has many effects. It has not only promoted the progress of medicine, but also promoted the friendly exchanges between China and foreign countries and the mutual dissemination of ideas and cultures, and greatly enriched the material and cultural life of the people of all countries.
RESUMEN
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.
Asunto(s)
Fibroínas/química , Hidrogeles/química , Ácido Hialurónico/química , Materiales Biocompatibles/química , Química Clic , Compuestos de Sulfhidrilo , Seda/químicaRESUMEN
This study evaluated the toxic effects of organic extracts of Calotropis proceraleaves on the survival, development, and reproduction of Spodoptera frugiperda. Solutions of crude methanol extract and hexane and methanol fractions of C. proceraleaves were added at 1.15% and 2.14% concentrations to the artificial diet of S. frugiperda. The mortality and duration of larval and pupal phases, weights of female and male pupae, deformations of pupae and adults, the reduction of adults able to reproduce, pre-oviposition and oviposition periods, the number of postures per female, and the fecundity and fertility of S. frugiperdafemales were also evaluated. The extracts harmed the survival, development, and reproduction of S. frugiperda. The ingestion of extracts and fractions by caterpillars affected adults by decreasing the oviposition period, the number of postures, fecundity, and fertility. The crude MeOH extract at a2.14% concentration harmed the evaluated parameters of the insect, except for pupal mortality, female pupae weight, and pre-oviposition period. The MeOH fraction at 2.14% caused a 50.0% mortality of caterpillars and 16.0% deformation in pupae and 33.0% inadults, reducing by 72.0% the population able to reproduce. The MeOH fraction at the 2.14% concentration caused 25.0% and 38.0% of pupal mortality and deformation, respectively. Calotropis procerahas promising insecticidal properties for a biological insecticide, a convenient and sustainable strategy for protecting plants against S. frugiperda.
Asunto(s)
Spodoptera , Calotropis/toxicidadRESUMEN
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.
Asunto(s)
Extractos Vegetales , Butea , Azadirachta , Litchi , Seda , AntiinfecciososRESUMEN
Abstract Objective: This study aimed to develop a pro-angiogenic hydrogel with in situ gelation ability for alveolar bone defects repair. Methodology: Silk fibroin was chemically modified by Glycidyl Methacrylate (GMA), which was evaluated by proton nuclear magnetic resonance (1H-NMR). Then, the photo-crosslinking ability of the modified silk fibroin was assessed. Scratch and transwell-based migration assays were conducted to investigate the effect of the photo-crosslinked silk fibroin hydrogel on the migration of human umbilical vein endothelial cells (HUVECs). In vitro angiogenesis was conducted to examine whether the photo-crosslinked silk fibroin hydrogel would affect the tube formation ability of HUVECs. Finally, subcutaneous implantation experiments were conducted to further examine the pro-angiogenic ability of the photo-crosslinked silk fibroin hydrogel, in which the CD31 and α-smooth muscle actin (α-SMA) were stained to assess neovascularization. The tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were also stained to evaluate inflammatory responses after implantation. Results: GMA successfully modified the silk fibroin, which we verified by our 1H-NMR and in vitro photo-crosslinking experiment. Scratch and transwell-based migration assays proved that the photo-crosslinked silk fibroin hydrogel promoted HUVEC migration. The hydrogel also enhanced the tube formation of HUVECs in similar rates to Matrigel®. After subcutaneous implantation in rats for one week, the hydrogel enhanced neovascularization without triggering inflammatory responses. Conclusion: This study found that photo-crosslinked silk fibroin hydrogel showed pro-angiogenic and inflammation inhibitory abilities. Its photo-crosslinking ability makes it suitable for matching irregular alveolar bone defects. Thus, the photo-crosslinkable silk fibroin-derived hydrogel is a potential candidate for constructing scaffolds for alveolar bone regeneration.
RESUMEN
There has long been a relationship between India, China, and Central Asia (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan). The Silk Route served as this triad's conduit to Europe and other western countries historically as well. The major declarations made during the first fictitious India-Central Asia conference under Prime Minister Modi and the competition for the same from his Chinese counterpart show how important Central Asia is to both India and China even now. Even though Central Asian countries and both China and India are members of the S.C.O., there is still a geopolitical struggle and a tremendous game going on. India and China's engagements are still influenced by Afghanistan in distinct ways. This research will discuss the historical and contemporary patterns of Indian and Chinese interactions in Central Asia. By obtaining access to the world's supply systems via Central Asia, it would also draw attention to the struggle for supremacy. As both India and China have enormous production facilities, the huge and untapped market and the availability of raw resources will eventually strengthen these interactions
RESUMEN
Objective:To investigate the effect of tissue engineered bladder patch constructed by double-layer silk scaffold and adipose-derived stem cells (ADSCs) in the repair and reconstruction of bladder.Methods:This study was conducted from May 2020 to March 2021. The silk fibroin (SF) aqueous solution was obtained from silkworm cocoons, and a double-layer silk scaffold composed of silk fibroin film and silk fibroin sponge was further prepared. The rat ADSCs were isolated, cultured, and the ADSCs surface markers (CD29, CD90, CD45, CD106) were identified by flow cytometry. The ADSCs were planted on a double-layer silk scaffold to construct a tissue-engineered bladder patch. Thirty-six male SD rats were randomly divided into three groups: tissue engineered bladder patch group (SF-ADSCs group, n=15), double-layer silk scaffold group (SF group, n=15), control group ( n=6). The tissue engineered bladder patch (SF-ADSCs group) and double-layer silk scaffold (SF group) were wrapped on the omentum to promote vascularization. The vascularization was evaluated by HE and immunofluorescence staining. The wrapped tissue engineered bladder patch and double-layer silk scaffold were used to repair the defective bladder. In the control group (six rats), the incision was closed immediately after the bladder tissue fully exposed. At 4 weeks and 12 weeks after operation, the general morphology of bladder tissue and cystography were performed to evaluate the recovery of bladder morphology. After the graft was harvested, HE and Masson's trichrome staining and immunofluorescence staining were used to observe the regeneration of bladder wall tissue. Urodynamics was used to assess the recovery of bladder function at 12 weeks after operation. Results:The flow cytometry results confirmed that the isolated cells positively expressed CD29 and CD90, and there was no significant expression of CD45 and CD106. Gross observation and scanning electron microscope confirmed that the preparation of double-layer silk scaffold not only had a pore structure that was conducive to cell planting, but also had good toughness and was facilitated to surgical suture. The number (43.50±2.66) and area (0.73±0.03)% of vascular-like structures in the SF-ADSCs group after the omentum encapsulation was significantly higher than that in the SF group [(24.50±3.51), (0.55±0.05)%], and the difference was statistically significant ( P<0.05). At 4 weeks after bladder repair, the histological staining of the grafts in the SF-ADSCs and SF groups showed a large number of degraded fragments of double-layer silk scaffold. At 12 weeks, the morphology of the graft in the SF-ADSCs group showed uniform bladder morphology, which was similar to that of normal bladder tissue. Immunofluorescence staining showed that the continuous urothelial layer, abundant smooth muscle tissue, vascular structure and regenerated neurons could be observed in the SF-ADSCs group. Urodynamic test showed that the bladder maximum volume (0.74±0.03)ml and compliance (16.68±0.44)μl/cm H 2O in the SF-ADSCs group, which were better than that in the SF group [(0.47±0.05)ml, (14.89±0.37)μl/cm H 2O], but lower than that in the control group [(1.12±0.08)ml, (19.34±0.45)μl/cm H 2O], and the difference was statistically significant ( P<0.05). Conclusions:The tissue engineered bladder patch constructed with double-layer silk scaffolds and ADSCs could promote the morphological repair of bladder tissue, the regeneration of bladder wall structure and the recovery of bladder physiological function.
RESUMEN
OBJECTIVE To prepare apigenin silk fibroin（API@SF）nanoparticles and to evaluate their safety and anti-tumor activity. METHODS API@SF nanoparticles were prepared by nanoprecipitation method ，and their morphology ，particle size ，Zeta potential，drug loading amount and in vitro release were characterized. The safety of nanoparticles was evaluated by hemolysis test and HE staining. MTT assay was adopted to evaluate inhibitory effects of API@SF nanoparticles on breast cancer 4T1 cells in mice. RESULTS The prepared API@SF nanoparticles were spherical with uniform distribution. The average particle size was 406.61 nm， the polydispersity index was 0.154，the Zeta potential was －18.4 mV，and the average drug-loading amount was 5.20％. The in vitro release results showed that the release rate of the nanoparticles was relatively fast in the release medium of pH 5.0 and relatively slow in the release medium of pH 7.4. Results of hemolysis test and HE staining showed that the nanoparticles had good biocompatibility. Results of MTT assay showed that the inhibitory effect of API@SF nanoparticles on 4T1 cells was significantly higher than that of API raw materials （P＜0.05），and its mechanism may be related to increasing the level of reactive oxygen species in cells. CONCLUSIONS API@SF nanoparticles are prepared successfully ，which possess good safety and anti-tumor activity.
RESUMEN
Incorporation of multiple functions into one nanoplatform can improve cancer diagnostic efficacy and enhance anti-cancer outcomes. Here, we constructed doxorubicin (DOX)-loaded silk fibroin-based nanoparticles (NPs) with surface functionalization by photosensitizer (N770). The obtained nanotheranostics (N770-DOX@NPs) had desirable particle size (157 nm) and negative surface charge (-25 mV). These NPs presented excellent oxygen-generating capacity and responded to a quadruple of stimuli (acidic solution, reactive oxygen species, glutathione, and hyperthermia). Surface functionalization of DOX@NPs with N770 could endow them with active internalization by cancerous cell lines, but not by normal cells. Furthermore, the intracellular NPs were found to be preferentially retained in mitochondria, which were also efficient for near-infrared (NIR) fluorescence imaging, photothermal imaging, and photoacoustic imaging. Meanwhile, DOX could spontaneously accumulate in the nucleus. Importantly, a mouse test group treated with N770-DOX@NPs plus NIR irradiation achieved the best tumor retardation effect among all treatment groups based on tumor-bearing mouse models and a patient-derived xenograft model, demonstrating the unprecedented therapeutic effects of trimodal imaging-guided mitochondrial phototherapy (photothermal therapy and photodynamic therapy) and chemotherapy. Therefore, the present study brings new insight into the exploitation of an easy-to-use, versatile, and robust nanoplatform for programmable targeting, imaging, and applying synergistic therapy to tumors.