Assembiy Of Intercalated LDHs And The Sustained Release Performance For Both Host And Guest Components

With the deteriorating of environment and the changing of lifestyle,skin allergy has become a common disease endangering people’s skin health,and the main cause is the disfunction of epidermal barrier caused by the loss of calcium in the skin.Calcium amino acid chelate is generally used to provide calcium to the skin percutaneously,but the concentration of Ca2+ will reach a high value in very short period of time,which is not conducive to the absorption of Ca2+by the skin and affects the treatment effect.Layered double hydroxides(LDHs)have been widely used as a body-friendly drug delivery carrier,and its host metal ions and interlayer guest molecules can be slowly released under certain conditions.Therefore,the construction of absorbable calcium based intercalated LDHs sustained release agent is of important practical application value for promoting the repair of skin epidermal barrier function,and theoretical significance for studying the slow release of LDHs host-guest structure.In this paper,the influence of different host or guest compositions on the sustained release process of lamination metal ion is studied.And corresponding theory about LDHs sustained release is enriched from the aspects of lamination metal element composition,charge density and interlayer guest.It is found that the element composition(Mg,Ca,Al)and ratio(M2+/M3+=2,3,4)(M2+and M3+are divalent and trivalent metal cations,respectively)of the laminate have relatively little effect on the slow release process of metal ions,while the interlayer guests(CO32-,NO3-and Glu-)have a greater impact on the sustained release process of metal ions.The concentration of metal cations in the solution of CO32--LDHs decreases rapidly with time during the sustained release process,while the concentration of metal cations in the sustained release process of NO3--LDHs and Glu-LDHs gradually increases and tends to be stable,reflecting excellent long-term sustained release performance.In addition,Glu-LDHs have a higher stable metal ion concentration in the solution than that of NO3--LDHs,indicating that after Glu is introduced into the LDHs interlayer,the release quantity of metal ions is increased and corresponding material utilization rate is improved.Furthermore,by comparing Mg2Al-Glu-LDHs and Mg3CaAl2-Glu-LDHs with high-efficiency metal ion sustained release properties,it was found that the introduction of calcium in the laminate significantly improved the release quantity and final concentration of Glu.Thus,Mg3CaAl2-Glu-LDHs can be used as an efficient calcium sustained release material,and have the potential application as a transdermal supplement agent of skin calcium.In this paper,Mg,Al,Ca elements and glutamate ions were introduced into the main layer and interlayer of LDHs.The body-friendly calcium ion and amino acid can be released at the same time.The effects of laminate composition and interlayer anions on the sustained release behavior of LDHs were studied,and the understanding of the sustained release process of intercalated LDHs was improved.This work provides a facile method for the preparation of calcium based sustained release agent and theoretical basis for skin calcium supplementation through percutaneous absorption.