Design Of Low-molecular-weight Organogel Based On Amino Acid Modified By Phenylboronic Acid For Biomedical Applications

Low-molecular-weight organogels(LMOGs)have received great attention for their good biocompatibility and high sensitivity to the environment.This paper focuses on designing a series of LMOGs based on phenylboronic acid modified amino acids for their applications in drug carrier and tissue engineering.Firstly,a series of gly-gly-gly tripeptide based on natural amino acid were synthesized as the matrix inducing stem cells differentiation.The gelators can gelate in a variety of alcohols' solvents,and the gelation can be adjusted by the length of alkyl chain.It was proved that intermolecular hydrogen bond,?-? accumulation effect,and van der Waals force were the main driving forces of gelation,characterized by NMR,UV and rheology.This organogel has good ability to inducing ectomesenchymal stem cells(mesenchymal stem cells,MSC)differentiate into osteoblasts and chondrocytes,with the elastic modulus between 103~105 Pa adjusted by the proportion of hydrophilic/hydrophobic segments.Secondly,a LMOG gated mesoporous silica(MSN)drug carrier has been fabricated using the non-covalent bonding between glucose-sensitive organogel and mesoporous silica.This drug carrier had good drug loading ability of phenformin.The drug release rate could be regulated by the concentration of glucose.And the pH responsive of the gate could control the release of adriamycin and phenformin.The gel gating mesoporous silica drug carrier has good glucose/pH sensitive controlled release properties.Third,a class of novel LMOG based on phenylboronic acid modified lysine was synthesized,its gel mechanism and glucosesensitivity were also studied by using the NMR,FTIR,UV and SEM.It was found the gelators of N?-acetyl-N?-lauroyl-lysine with different length of alkyl chain had good gelation ability.The gelators of these salt or the derivatives modified by different number of mino acids or phenylboronic acid still had good gel properties.There gels also had good glucose sensitivity by online UV dynamics study.