Viscoelastic Properties and Bioactivity of Sol-Gel Derived Gelatin-Silicate Composites: Effects of the Incorporated Ca^(2+) Ions

Several gelatin-silicate composites, with or without incorporation of Ca2+ ions, were synthesized through sol-gel processing starting from gelatin and 3- (glycidoxypropyl) trimethoxysilane. The structure around the Si atoms was similar for all the samples. The measurement of viscoelastic properties indicated that the glass transition temperature and activation energy decreased with the incorporation of Ca2+ ions. The Ca2+ ion-containing composites were bioactive as they spontaneously deposited apatite when soaked in a simulated body fluid of the Kokubo recipe.

Effects of lactic acid bacteria fermentation on the bioactive composition,volatile compounds and antioxidant activity of Huyou(Citrus aurantium'Changshan-huyou')peel and pomace

Using lactic acid bacteria(LAB)to ferment Huyou peel and pomace could provide a reference for making full use of Huyou resources and provide valuable suggestions for the industrial production of functional foods.The effects of LAB fermentation on the bioactive composition,volatile compounds and antioxidant activity of Huyou peel and pomace were studied.Results showed that both Huyou peel and pomace were good substrates for LAB growth.LAB had remarkable influence on bioconversion of organic acids,among which ascorbic acid content was increased significantly.In addition,LAB could produce flavonoids with enhanced bioactivity and absorption.In particular,the contents of rhoifolin,quercitrin and quercetin were increased by over 100%.Besides,the volatile compounds contents and aroma complexity were improved.Furthermore,the antioxidant activity was enhanced.Thus,our study provides high-value applications of Huyou,and fermented products with improved nutritional value and flavor are potentially beneficial to human health.

3D bioactive composite scaffolds for bone tissue engineering

Bone is the second most commonly transplanted tissue worldwide,with over four million operations using bone grafts or bone substitute materials annually to treat bone defects.However,significant limitations affect current treatment options and clinical demand for bone grafts continues to rise due to conditions such as trauma,cancer,infection and arthritis.Developing bioactive three-dimensional(3D)scaffolds to support bone regeneration has therefore become a key area of focus within bone tissue engineering(BTE).A variety of materials and manufacturing methods including 3D printing have been used to create novel alternatives to traditional bone grafts.However,individual groups of materials including polymers,ceramics and hydrogels have been unable to fully replicate the properties of bone when used alone.Favourable material properties can be combined and bioactivity improved when groups of materials are used together in composite 3D scaffolds.This review will therefore consider the ideal properties of bioactive composite 3D scaffolds and examine recent use of polymers,hydrogels,metals,ceramics and bio-glasses in BTE.Scaffold fabrication methodology,mechanical performance,biocompatibility,bioactivity,and potential clinical translations will be discussed.

Poly(1,8-octanediol citrate)/bioactive glass composite with improved mechanical performance and bioactivity for bone regeneration

Poly（1,8-octanediol-co-citrate） （POC） represents a new promising biocompatible and biodegradable polyester that has been extensively investigated for soft tissue engineering. However, the poor mechanical performance and poor bioactivity limit its application in bone regeneration. In this study, a series of POC/bioactive glasses （BG） composites were developed using 45S5 Bioglass^Θ and a phytic acid- derived bioactive glass （referred as PSC）. The results indicated that calcium in BG could enhance the crosslinking of the POC/BG composites by forming calcium dicarboxylate bridges and thus improve their mechanical performances. When PSC were used, the composites exhibited significantly better mechanical properties compared to composites with 45S5 Bioglass^Θ. For example, by incorporating 70wt% PSC, the compressive strength of POC/PSC composites could be improved to approximately 50 MPa and modulus 1.3-h 0.1 GPa. Furthermore, all these POC/PSC composites showed good in vitro bioactivity and cellular biocompatibility. Histology results in femoral condyle defects of Sprague-Dawley rats indicated that the POC/PSC samples integrated well with surrounding tissues and stimulated bone regeneration. The improved mechanical properties and bioactivity of POC/PSC composites make them promising for potential application in bone regeneration.

3D-printed porous functional composite scaffolds with polydopamine decoration for bone regeneration

Large size bone defects affect human health and remain a worldwide health problem that needs to be solved immediately.3D printing technology has attracted substantial attention for preparing penetrable multifunctional scaffolds to promote bone reconditioning and regeneration.Inspired by the spongy structure of natural bone,novel porous degradable scaffolds have been printed using polymerization of lactide and caprolactone(PLCL)and bioactive glass 45S5(BG),and polydopamine(PDA)was used to decorate the PLCL/BG scaffolds.The physicochemical properties of the PLCL/BG and PLCL/BG/PDA scaffolds were measured,and their osteogenic and angiogenic effects were characterized through a series of experiments both in vitro and in vivo.The results show that the PLCL/BG2/PDA scaffold possessed a good compression modulus and brilliant hydrophilicity.The proliferation,adhesion and osteogenesis of hBMSCs were improved in the PDA coating groups,which exhibited the best performance.The results of the SD rat cranium defect model indicate that PLCL/BG2/PDA obviously promoted osteointegration,which was further confirmed through immunohistochemical staining.Therefore,PDA decoration and the sustained release of bioactive ions(Ca,Si,P)from BG in the 3D-printed PLCL/BG2/PDA scaffold could improve surface bioactivity and promote better osteogenesis and angiogenesis,which may provide a valuable basis for customized implants in extensive bone defect repair applications.