Synthesis And Performance Study Of CaCO₃/DNA-calcium Alginate Composite Hydrogel

The antibacterial and bactericidal effects of sodium alginate can reduce bacterial infection at the wound site.Sodium alginate with excellent water absorption properties can absorb wound exudate.Sodium alginate has excellent moisturizing properties and provides a moist environment for wound healing.The complex of low molecular DNA（polydeoxynucleotide）extracted from salmon white can improve the internal environment of human skin,effectively eliminate the root cause of inflammation,and promote the regeneration of skin cells.Spermine（SPM）has the effect of promoting cell proliferation and differentiation and cell repair,and has an effect on DNA synthesis,transcription and protein synthesis.Calcium carbonate nanoparticles can be loaded with DNA and SPM,and can be used as calcium source to crosslink sodium alginate and chitosan to prepare composite hydrogel.In this paper,we mainly constructed CaCO₃/DNA hybrid particles and CaCO₃/DNA-calcium alginate composite hydrogel.The main research work and results are as follows:（1）The polydeoxynucleotide was loaded into CaCO₃ by co-deposition method to obtain CaCO₃/DNA complex,which was found to be 300 nm spherical by scanning electron microscope and DLS characterization.The content of DNA in the CaCO₃/DNA complex is33.38%.By detecting the growth curve of the cells under the action of the complex,it is confirmed that polydeoxynucleotide has the effect of promoting cell growth.（2）Subsequently,nano-composite hydrogels were prepared using sodium alginate（SA）,chitosan,CaCO₃/DNA complex,and gluconolactone（GDL）.CaCO₃ will decompose in the presence of gluconolactone,and the slow-release Ca²⁺will cross-link the alginate to form a uniform hydrogel.At the same time,the polydeoxynucleotide released by the decomposition of the CaCO₃/DNA complex can promote wound healing.（3）Spermine is a polyamine containing two amino groups and two imino groups,and is an important substance to promote cell proliferation.The DNA and SPM were loaded into CaCO₃ to obtain the CaCO₃/DNA/SPM complex.Using the CaCO₃/DNA/SPM complex as the calcium source,a nano-composite calcium alginate hydrogel was prepared.