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Scaffolds for bone tissue engineering require considerable mechanical strength to repair damaged bone defects. In this study, we designed and developed mechanically competent composite shape memory triphasic bone scaffolds using fused filament fabrication (FFF) three dimensional (3D) printing. Wollastonite particles (WP) were incorporated into the poly lactic acid (PLA)/polycaprolactone (PCL) matrix as a reinforcing agent (up to 40 wt%) to harness osteoconductive and load-bearing properties from the 3D printed scaffolds. PCL as a minor phase (20 wt%) was added to enhance the toughening effect and induce the shape memory effect in the triphasic composite scaffolds. The 3D-printed composite scaffolds were studied for morphological, thermal, and mechanical properties, in vitro degradation, biocompatibility, and shape memory behaviour. The composite scaffold had interconnected pores of 550 μm, porosity of more than 50%, and appreciable compressive strength (∼50 MPa), which was over 90% greater than that of the pristine PLA scaffolds. The flexural strength was improved by 140% for 40 wt% of WP loading. The inclusion of WP did not affect the thermal property of the scaffolds; however, the inclusion of PCL reduced the thermal stability. An accelerated in vitro degradation was observed for WP incorporated composite scaffolds compared to pristine PLA scaffolds. The inclusion of WP improved the hydrophilic property of the scaffolds, and the result was significant for 40 wt% WP incorporated composite scaffolds having a water contact angle of 49.61°. The triphasic scaffold exhibited excellent shape recovery properties with a shape recovery ratio of ∼84%. These scaffolds were studied for their protein adsorption, cell proliferation, and bone mineralization potential. The incorporation of WP reduced the protein adsorption capacity of the composite scaffolds. The scaffold did not leach any toxic substance and demonstrated good cell viability, indicating its biocompatibility and growth-promoting behavior. The osteogenic potential of the WP incorporated scaffolds was observed in MC3T3-E1 cells, revealing early mineralization in pre-osteoblast cells cultured in different WP incorporated composite scaffolds. These results suggest that 3D-printed WP reinforced PLA/PCL composite bioactive scaffolds are promising for load bearing bone defect repair. [ABSTRACT FROM AUTHOR]

Activation of cellular defence and immunity in the ovary is critical to protect it from pathogenic infection. In this study cellular and innate immunity in larval and pupal ovaries of Bombyx mori induced by the microsporidian Nosema bombycis is reported. Autophagic vacuoles enclosing spores in flat cells of the larval ovarian disc revealed cellular defence. In the follicular epithelium of differentiated previtellogenic ovarioles of infected pupae, a network of RER and phagosomes observed probably to maintain cellular homeostasis. In larval and pupal ovaries, paralytic peptide titre, tyrosine content and phenoloxidase activity were enhanced revealing greater melanisation, which was confirmed by activation of melanisation genes, DDC, prophenoloxidase activating enzyme, prophenoloxidase 1 (PPO1) and PPO2 after infection. βGRP-2, βGRP-4, CTL-11, Humoral lectin, Toll-6, Spätzle, Cactus, Relish, Pelle, and Dorsal genes showed differential expression in infected larval and pupal ovaries. Pupal ovarioles showed decreased expression and lower Spätzle titre than the larval ovary revealing suppression of innate immunity in the pupal ovary. Dorsal showed decreased expression, however, Pelle enhanced expression to maintain immunity through alternate components in differentiated ovarioles. Our data showed that coupled with cellular defence reactions, innate immune reactions and melanisation are activated in the developing ovary to defend against N. bombycis infection. [ABSTRACT FROM AUTHOR]

Different parts of the mulberry plant are described to be potential sources of polyphenolics exhibiting strong antioxidant activity. In this study, we prepared various aqueous extracts of mulberry root bark by subjecting to steam at different temperatures and time intervals (45oC, 15 h; 70oC, 15 h; 95oC, 6 h and 95oC, 15 h) followed by extracting at 80oC for 1 h. The total polyphenolic content ranged from 66.82-101.20 mg gallic acid equivalent (GE)/g of extract whereas the flavonoids were in the range of 13.03-25.23 mg catechin equivalent (CE)/g of extract. The extracts also exhibited strong antioxidant activities (0.99-1.66 mg trolox equivalent (TE)/g of extract in DDPH assay and 10.65-16.26 mg TE/g of extract in ABTS assay). This study clearly showed an improvement in the antioxidant activity of the water extract of mulberry root bark by the steam treatment, which can be used as a tea or health-promoting materials. [ABSTRACT FROM AUTHOR]