The strength-to-weight ratio of ** sponges cross-linked with glucose and citric acid was 150% and 120% higher compared to that of unmodified ** sponge. In vitro assays revealed that the modified ** sponges are non-cytotoxic and do not trigger an inflammatory response in macrophages. https://www.selleckchem.com/products/sovilnesib.html This study provides a simple and green method to obtain highly porous cellulose sponges with hierarchical design, biocompatibility and good mechanical properties. As a degradable metal, zinc (Zn) has attracted an immense amount of interest as the next generation of bioresorbable implants thanks to its modest corrosion rate and its vital role in bone remodeling, yet very few studies have thoroughly investigated its functionality as a porous implant for bone tissue engineering purposes. Zn bone scaffolds with two different pore sizes of 900 μm and 2 mm were fabricated using additive manufacturing-produced templates combined with casting. The compressive properties, corrosion rates, biocompatibility, and antibacterial performance of the bioscaffolds were examined and compared to a non-porous control. The resulting textured and porous Zn scaffolds exhibit a fully interconnected pore structure with precise control over topology. As pore size and porosity increased, mechanical strength decreased, and corrosion rate accelerated. Cell adhesion and growth on scaffolds were enhanced after an ex vivo pretreatment method. In vitro cellular tests confirmed good biocompatibility of the scaffolds. As porosity increased, potent antibacterial rates were also observed. Taken together, these results demonstrate that Zn porous bone scaffolds are promising for orthopedic applications. This paper introduces a new hybrid microfabrication technique which combines ultra-precision micro-milling and a ductile sacrificial material deposition process to fabricate a silicon-based implant for neuroprosthetics applications with near defect-free quality at several hundreds of micrometres in thickness. The sacrificial materials can influence the quality of silicon during machining. The cutting mechanism and feasibility of the hybrid technique are studied by molecular dynamics (MD) simulations and experiments. Due to the complexity of modelling PMMA and SU-8 structures in MD environment, only copper was modelled as the simulation is intended to understand the performance of using a ductile sacrificial layer structure in silicon machining. MD analysis shows that the reduced stress intensity and subsurface damage were mainly attributed to workpiece plasticity enhancement, where its mechanism was contributed by better deformability of the ductile sacrificial layer and enhanced thermal softening from the heat generated by the high interfacial stress between the sacrificial layer and silicon substrate. Despite the MD simulation and experiment having different machining scale in terms of cutting parameters, phenomenal behaviours of the cutting performance when observed under the experimental conditions are in good agreement with simulation. Experimental verification shows that near defect-free quality was achieved at large cutting depth of 150 μm when silicon is coated either with PMMA or SU-8. An exemplary implant structure was also fabricated to better demonstrate the hybrid technique's capability. In addition, the hybrid technique will be beneficial for low volume high customisation applications as it is a serial process. The emergence of bacterial resistance has become one of the top global concern, and silver nanoparticles (AgNPs) provide alternative strategies for the development of new antimicrobial agent. Herein, three small sizes (1.5-4.0 nm) of well-dispersed AgNPs were successfully synthesized using a thermo-sensitive P(NIPAM-co-MQ) copolymer with coordination ability as a stabilizer. The copolymer stabilized silver nanoparticles (AgNPs@P) displayed good thermo-sensitive characteristics and solution stability at pH = 6.5-8.0. AgNPs@P had high-efficiency and long-term antimicrobial properties for Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli). In particular, AgNPs@P3 with ultrasmall size (1.59 nm) exhibited better antimicrobial activity against both normal bacteria and antibiotic-resistant bacteria with a very low ****value of 4.05 μg/mL. Moreover, AgNPs@P also showed an interesting temperature-dependent antibacterial activity mainly owing to the effect of thermo-sensitive copolymer on AgNPs. It was found that the antibacterial activity of the AgNPs@P also was affected by the proportion of copolymer, sizes of AgNPs, and experimental temperature. The antibacterial mechanism of AgNPs@P involved a variety of ways including destroying cell membranes, internalization of AgNPs and generation of ROS. Our research provides a new perspective for the preparation of effective nanosilver antimicrobial agents. V.Scaffold geometry is known a biophysical spatial cue to modulate stem cell fate. However, the effect of regulating topography on the chondrogenic differentiation of adipose-derived stem cells (ADSCs) is not fully understood. In this study, a spatial-controlled scaffold was prepared using a microfluidic device with a reference freeze-dried prepared random porous scaffold. Rabbit ADSCs were seeded into the organized or random scaffolds to evaluate the regulation of spatial cue to chondrogenesis. In addition to viability, the ADSC-derived chondrocytes had relatively higher glycosaminoglycan productions in the organized scaffolds than in the random scaffolds. Cells spontaneously aggregated as spheroids within the microbubble of the organized scaffolds, while non-uniform distribution of cells was noticed in the random ones. In addition, the differentiated chondrocytes in organized scaffolds displayed a higher level of COL2A1 and SOX-9 but lower COL10 mRNA expression relative to those in random scaffolds, suggesting that scaffold geometry influenced chondrogenic differentiation to ADSCs. Otherwise, the scaffold geometry also regulated the orientation of cytoskeletons. The signal intensity of ADSCs/organized scaffolds in MRI was similar with the native cartilage of stifle joint. Moreover, histological examinations showed that the ADSCs/organized scaffold samples retrieved from SCID **** had a functional phenotype as hyaline cartilage. In conclusion, the cues from spatial structure affect the chondrogenic differentiation to ADSCs which suggesting that organized scaffold shall benefit cartilage regeneration.
The strength-to-weight ratio of BC sponges cross-linked with glucose and citric acid was 150% and 120% higher compared to that of unmodified BC sponge. In vitro assays revealed that the modified BC sponges are non-cytotoxic and do not trigger an inflammatory response in macrophages. https://www.selleckchem.com/products/sovilnesib.html This study provides a simple and green method to obtain highly porous cellulose sponges with hierarchical design, biocompatibility and good mechanical properties. As a degradable metal, zinc (Zn) has attracted an immense amount of interest as the next generation of bioresorbable implants thanks to its modest corrosion rate and its vital role in bone remodeling, yet very few studies have thoroughly investigated its functionality as a porous implant for bone tissue engineering purposes. Zn bone scaffolds with two different pore sizes of 900 μm and 2 mm were fabricated using additive manufacturing-produced templates combined with casting. The compressive properties, corrosion rates, biocompatibility, and antibacterial performance of the bioscaffolds were examined and compared to a non-porous control. The resulting textured and porous Zn scaffolds exhibit a fully interconnected pore structure with precise control over topology. As pore size and porosity increased, mechanical strength decreased, and corrosion rate accelerated. Cell adhesion and growth on scaffolds were enhanced after an ex vivo pretreatment method. In vitro cellular tests confirmed good biocompatibility of the scaffolds. As porosity increased, potent antibacterial rates were also observed. Taken together, these results demonstrate that Zn porous bone scaffolds are promising for orthopedic applications. This paper introduces a new hybrid microfabrication technique which combines ultra-precision micro-milling and a ductile sacrificial material deposition process to fabricate a silicon-based implant for neuroprosthetics applications with near defect-free quality at several hundreds of micrometres in thickness. The sacrificial materials can influence the quality of silicon during machining. The cutting mechanism and feasibility of the hybrid technique are studied by molecular dynamics (MD) simulations and experiments. Due to the complexity of modelling PMMA and SU-8 structures in MD environment, only copper was modelled as the simulation is intended to understand the performance of using a ductile sacrificial layer structure in silicon machining. MD analysis shows that the reduced stress intensity and subsurface damage were mainly attributed to workpiece plasticity enhancement, where its mechanism was contributed by better deformability of the ductile sacrificial layer and enhanced thermal softening from the heat generated by the high interfacial stress between the sacrificial layer and silicon substrate. Despite the MD simulation and experiment having different machining scale in terms of cutting parameters, phenomenal behaviours of the cutting performance when observed under the experimental conditions are in good agreement with simulation. Experimental verification shows that near defect-free quality was achieved at large cutting depth of 150 μm when silicon is coated either with PMMA or SU-8. An exemplary implant structure was also fabricated to better demonstrate the hybrid technique's capability. In addition, the hybrid technique will be beneficial for low volume high customisation applications as it is a serial process. The emergence of bacterial resistance has become one of the top global concern, and silver nanoparticles (AgNPs) provide alternative strategies for the development of new antimicrobial agent. Herein, three small sizes (1.5-4.0 nm) of well-dispersed AgNPs were successfully synthesized using a thermo-sensitive P(NIPAM-co-MQ) copolymer with coordination ability as a stabilizer. The copolymer stabilized silver nanoparticles (AgNPs@P) displayed good thermo-sensitive characteristics and solution stability at pH = 6.5-8.0. AgNPs@P had high-efficiency and long-term antimicrobial properties for Gram-positive bacteria (S. aureus) and Gram-negative bacteria (E. coli). In particular, AgNPs@P3 with ultrasmall size (1.59 nm) exhibited better antimicrobial activity against both normal bacteria and antibiotic-resistant bacteria with a very low MIC value of 4.05 μg/mL. Moreover, AgNPs@P also showed an interesting temperature-dependent antibacterial activity mainly owing to the effect of thermo-sensitive copolymer on AgNPs. It was found that the antibacterial activity of the AgNPs@P also was affected by the proportion of copolymer, sizes of AgNPs, and experimental temperature. The antibacterial mechanism of AgNPs@P involved a variety of ways including destroying cell membranes, internalization of AgNPs and generation of ROS. Our research provides a new perspective for the preparation of effective nanosilver antimicrobial agents. V.Scaffold geometry is known a biophysical spatial cue to modulate stem cell fate. However, the effect of regulating topography on the chondrogenic differentiation of adipose-derived stem cells (ADSCs) is not fully understood. In this study, a spatial-controlled scaffold was prepared using a microfluidic device with a reference freeze-dried prepared random porous scaffold. Rabbit ADSCs were seeded into the organized or random scaffolds to evaluate the regulation of spatial cue to chondrogenesis. In addition to viability, the ADSC-derived chondrocytes had relatively higher glycosaminoglycan productions in the organized scaffolds than in the random scaffolds. Cells spontaneously aggregated as spheroids within the microbubble of the organized scaffolds, while non-uniform distribution of cells was noticed in the random ones. In addition, the differentiated chondrocytes in organized scaffolds displayed a higher level of COL2A1 and SOX-9 but lower COL10 mRNA expression relative to those in random scaffolds, suggesting that scaffold geometry influenced chondrogenic differentiation to ADSCs. Otherwise, the scaffold geometry also regulated the orientation of cytoskeletons. The signal intensity of ADSCs/organized scaffolds in MRI was similar with the native cartilage of stifle joint. Moreover, histological examinations showed that the ADSCs/organized scaffold samples retrieved from SCID mice had a functional phenotype as hyaline cartilage. In conclusion, the cues from spatial structure affect the chondrogenic differentiation to ADSCs which suggesting that organized scaffold shall benefit cartilage regeneration.
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