Strontium/Silicon/Calcium-Releasing Hierarchically Structured 3D-Printed Scaffolds Accelerate Osteochondral Defect Repair.

Articular cartilage defects are a global challenge, causing substantial disability. Repairing large defects is problematic, often exceeding cartilage's self-healing capacity and damaging bone structures. To tackle this problem, a scaffold-mediated therapeutic ion delivery system is developed. These scaffolds are constructed from poly(ε-caprolactone) and strontium (Sr)-doped bioactive nanoglasses (SrBGn), creating a unique hierarchical structure featuring macropores from 3D printing, micropores, and nanotopologies due to SrBGn integration. The SrBGn-embedded scaffolds (SrBGn-µCh) release Sr, silicon (Si), and calcium (Ca) ions, which improve chondrocyte activation, adhesion, proliferation, and maturation-related gene expression. This multiple ion delivery significantly affects metabolic activity and maturation of chondrocytes. Importantly, Sr ions may play a role in chondrocyte regulation through the Notch signaling pathway. Notably, the scaffold's structure and topological cues expedite the recruitment, adhesion, spreading, and proliferation of chondrocytes and bone marrow-derived mesenchymal stem cells. Si and Ca ions accelerate osteogenic differentiation and blood vessel formation, while Sr ions enhance the polarization of M2 macrophages. The findings show that SrBGn-µCh scaffolds accelerate osteochondral defect repair by delivering multiple ions and providing structural/topological cues, ultimately supporting host cell functions and defect healing. This scaffold holds great promise for osteochondral repair applications.

Lithium-loaded GelMA-Phosphate glass fibre constructs: Implications for astrocyte response.

Combinations of different biomaterials with their own advantages as well as functionalization with other components have long been implemented in tissue engineering to improve the performance of the overall material. Biomaterials, particularly hydrogel platforms, have shown great potential for delivering compounds such as drugs, growth factors, and neurotrophic factors, as well as cells, in neural tissue engineering applications. In central the nervous system, astrocyte reactivity and glial scar formation are significant and complex challenges to tackle for neural and functional recovery. GelMA hydrogel-based tissue constructs have been developed in this study and combined with two different formulations of phosphate glass fibers (PGFs) (with Fe3+ or Ti2+ oxide) to impose physical and mechanical cues for modulating astrocyte cell behavior. This study was also aimed at investigating the effects of lithium-loaded GelMA-PGFs hydrogels in alleviating astrocyte reactivity and glial scar formation offering novel perspectives for neural tissue engineering applications. The rationale behind introducing lithium is driven by its long-proven therapeutic benefits in mental disorders, and neuroprotective and pronounced anti-inflammatory properties. The optimal concentrations of lithium and LPS were determined in vitro on primary rat astrocytes. Furthermore, qPCR was conducted for gene expression analysis of GFAP and IL-6 markers on primary astrocytes cultured 3D into GelMA and GelMA-PGFs hydrogels with and without lithium and in vitro stimulated with LPS for astrocyte reactivity. The results suggest that the combination of bioactive phosphate-based glass fibers and lithium loading into GelMA structures may impact GFAP expression and early IL-6 expression. Furthermore, GelMA-PGFs (Fe) constructs have shown improved performance in modulating glial scarring over GFAP regulation.

Experimental Study on the Effects of Surfactants on Cellulase From Trichoderma viride / 中国生物工程杂志

The effects of surfactants on the production of cellulase by Trichoderma viride in liquid substrate fermentation process were investigated. Straw was used as the sole carbon source and the surfactants were biosurfactant rhamnolipid from Pseudomonas aeruginosa and Tween 80. The changes of FPA,CMCase,Avicelase and surface tension with time were analyzed under different concentrations of the two surfactants. The results showed that the surfactants can enhance the enzyme activity of Trichoderma viride. The FPA,CMCase,Avicelase were promoted 1.08,1.6 and 1.03 times higher than the controls by rhamnolipid. The enhancement of the enzyme activity by rhamnolipid was much higher than that of Tween 80. At the same time,rhamnolipid was not degraded prior to other substrate.

RECENT RESEARCH ON WHITE-ROT FUNGI AND ITS EXPECTED APPLICATION IN COMPOSTING / 微生物学通报

White-rot fungi is a kind of basidiomycetes making wood rotten. For their particular metabolism and extracellular degrading ability, they can degrade a lot of organic pollutants, and then become the hot point of international academic research. This paper reviews the recent research progress in many aspects,such as the sort and degradation mechanism of white rot fungus, advances in applied research for white rot fungi on industry and environmental pollution disposal and so on. In addition, some suggestions on the prospective application in the composting of municipal solid waste are presented in the end.