Gelatin-based Composites And Their Mechanical Properties

Gelatin were wildly used in the field of food packaging,biomaterials and medicine for its advantages of cheap,rich source,non-toxic,good biocompatibility.However,gelatin's poor mechanical properties has limited its applications.In this article,we used two kinds of nanoparticles and one kind of polymer to strengthen the gelatin.Our work is divided into the following three parts:(1)Nanosized 58S bioactive glass(BG)particles were synthesized by using a three-dimensional ordered macroporous carbon template(OMC)with a pore size of 400 nm.The obtained 58S BG particles possessed a diameter of 300 nm,narrow size distribution and uniform spherical morphology.58S/gelatin composites were prepared and showed much better mechanical properties than pure gelatin.The outstanding bioactivity of the 58S BG particles was confirmed by inducing the formation of carbonated hydroxyapatite on the 58S/gelatin composite surface.(2)Bone regeneration porous scaffolds with sustained drug release were developed by freeze-drying the mixture of nanosized drug-loaded halloysite nanotubes(HNTs)and gelatin.The scaffolds showed porous structure and excellent biocompatibility.The mechanical properties of the obtained composite scaffolds were enhanced significantly by HNTs to more than 300%,comparing to those of gelatin scaffold,and match to those of natural cancellous bones.The ibuprofen-loaded HNTs incorporated in the scaffolds allowed extended drug release over 100 hours,comparing to 8 hours when directly mixed the drug into the gelatin scaffold.The biological properties of the composite scaffolds were investigated by culturing MG63 cells on them.The HNTs/gelatin scaffolds with excellent mechanical properties and sustained drug release could be a promising artificial bone grating material.(3)PLA-PEG has increased the gelatins' performance even in the low addition.Hydrophilic chain segment in PLA-PEG and gelatin interact with each other,it caused the increase of barrier.The WVP of films reduce for almost 67%at most,and can even lower by continuing to add the PLA-PEG.When the addition of the PLA-PEG was 5%,the films got the greatest TS(55 MPa,increase 189.4%compare to gelatin)and EM(2141 MPa,increase 90.5%compared to gelatin).When the addition getting higher the PLA-PEG can not only strengthen but also soften the film,it may be caused by the change of microstructure.Also the films' ultraviolet shielding ability and oxygen isolation performance is much better than PLA film and has similar performance with gelatin film.Also the film has an appropriate time of degradation which indict its environment-friendliness and potential application in other field such as biomaterials.Overall,the gelatin/PLA-PEG composition provides a potential approach to improve gelatin film performance and benefit its applications in the food industry.