Preparation Of Transglutaminase Responsive Peptide Hydrogels And Their Application In Control Release

Hydrogels have a great potential as a new type of biomaterial.Researchers are eager to find a new method which for designing materials from the bottom up with the finest detail and ultimate control at the single molecular level.The discovery of a class of self-assembly peptides hydrogel opened a door for people to synthesize biomaterial.Since this discovery,diverse classes of short peptides have been invented with broad applications,including 3D cell culture,tissue engineering and drug release.As the basic unit of peptide,amino acid chirality and property are undoubtedly the key factors of influencing self-assembly.Researchers hope get a controllable self-assembly peptides hydrogel by design a peptide through reasonable and rational choice of amino acid.If there is an enzyme response site in the short peptide hydrogel,the system could perform several functions like gelation,degradation and functionalization under the stimulations of enzymes.Due to the advantages of enzyme-catalyzed reactions,this method of synthesizing hydrogels has become the most potential means of regulating gel properties.In this paper,the Transglutaminase response site was introduced into short peptides to design and synthesize Transglutaminase-responsive short peptides,and then their structure,cytotoxicity,and drug controlled release ability was studied subsequently.The main researches can be summarized as follows:Firstly,we designed and synthesized Ac-I₃QK-NH₂,Ac-I₃GQK-NH₂,and Ac-I₃QGK-NH₂ three peptids.We investigated the effect of amino acid sequencing changes on the performance of enzyme-responsive peptide hydrogels.it was found that the hydrophobic property played a major role in the formation of the fiber,and the hydrophobic property was enhanced so that the dimer of Ac-I₃GQK-NH₂ was easier to assemble and precipitated.And then,we replaced the L-type amino with D-type amino acid in the enzyme response site,to obtain Ac-I₃^DQG^DK-NH₂,Ac-I₃QG^DK-NH₂.Although Ac-I₃^DQG^DK-NH₂ does not form dimers after enzymatic reaction,it forms a stronger gel when mixed with Ac-I₃QGK-NH₂.Finally,the gel was encapsulated with protein molecules of different properties to examine the controlled release capacity of the gels.As a result,it was found that the obtained gels all have a good controlled release ability and do not reduce the effectiveness of protein molecules.