Biomimetic mineralized hybrid scaffolds with antimicrobial peptides

Infection in hard tissue regeneration is a clinically-relevant challenge.Development of scaffolds with dual function for promoting bone/dental tissue growth and preventing bacterial infections is a critical need in the field.Here we fabricated hybrid scaffolds by intrafibrillar-mineralization of collagen using a biomimetic process and subsequently coating the scaffold with an antimicrobial designer peptide with cationic and amphipathic properties.The highly hydrophilic mineralized collagen scaffolds provided an ideal substrate to form a dense and stable coating of the antimicrobial peptides.The amount of hydroxyapatite in the mineralized fibers modulated the rheological behavior of the scaffolds with no influence on the amount of recruited peptides and the resulting increase in hydrophobicity.The developed scaffolds were potent by contact killing of Gram-negative Escherichia coli and Gram-positive Streptococcus gordonii as well as cytocompatible to human bone marrow-derived mesenchymal stromal cells.The process of scaffold fabrication is versatile and can be used to control mineral load and/or intrafibrillar-mineralized scaffolds made of other biopolymers.

Bioactivity of mackerel peptides on obesity and insulin resistance,an in-vivo study

Of many metabolic irregularity risk factors,glucose intolerance,insulin resistance,and abdominal obesity are the main ones.The risk of vascular diseases and cancers is rather high in such individuals therefore its treatment and prevention are equally important for the health of population.Marine including fish biopeptides have frequently shown to prevent and or ameliorate these risk factors.In our earlier studies,Atlantic mackerel hydrolysate and its fractions showed promising effects on immunity and hypertension.We,therefore,in the current study,aimed to examine the effects of mackerel hydrolysate along its cationic peptides,isolated at pH3 using electrodialysis with ultrafiltration membrane,on metabolic disorder factors in diet-induced insulin resistant obese mice.Mice were fed the chow and or the hypercaloric diet (high fat high sucrose) for the duration of 8-weeks.Subsequently the hypercaloric fed insulin resistant obese mice were gavaged daily either the vehicle and or the test material at the dosage of 208 mg of sample protein per kg mice body weight.According to our observations,mackerel peptides could not effectively modulate food intake,weight gain,adiposity,plasma glucose and insulin concentrations,hepatic cholesterol,and triglyceride levels.Thus,obesity and metabolic impairments could not be averted by the treatments in insulin resistant obese mice.In conclusion,anti-hypertensive,and immunomodulatory attributes of mackerel peptides at the tested concentrations do not seem to be correlated with its metabolic syndrome benefiting effects.To presume a general statement about the metabolic syndrome benefiting potency of Atlantic mackerel's biopeptides further research is warranted.

Anti-lipopolysaccharide factor D from kuruma shrimp exhibits antiviral activity

Anti-lipopolysaccharide factors(ALFs)exhibit a potent antimicrobial activity against a broad range of bacteria,filamentous fungi,and viruses.In previous reports,seven groups of ALFs(groups A–G)were identified in penaeid shrimp.Among them,group D showed negative net charges and weak antimicrobial activity.Whether this group has antiviral function is not clear.In this study,the ALF sequences of penaeid shrimp were analyzed,and eight groups of ALF family(groups A–H)were identified.The four ALFs including MjALF-C2,MjALF-D1,MjALF-D2,and MjALF-E2 from kuruma shrimp Marsupenaeus japonicus were expressed recombinantly in Escherichia coli,and the antiviral activity was screened via injection of purified recombinant ALFs into shrimp following white spot syndrome virus(WSSV)infection.Results showed that the expression of Vp28(WSSV envelope protein)decreased significantly in the MjALF-D2-injected shrimp only.Therefore,MjALF-D2 was chosen for further study.Expression pattern analysis showed that MjAlf-D2 was upregulated in shrimp challenged by WSSV.The WSSV replication was detected in RNA,genomic DNA,and protein levels using VP28 and Ie1(immediate-early gene of WSSV)as indicators in MjALF-D2-injected shrimp following WSSV infection.Results showed that WSSV replication was significantly inhibited compared with that in the rTRX-or PBS-injected control groups.After knockdown of MjAlf-D2 in shrimp by RNA interference,the WSSV replication increased significantly in the shrimp.All these results suggested that MjALF-D2 has an antiviral function in shrimp immunity,and the recombinant ALF-D2 has a potential application for viral disease control in shrimp aquaculture.