|Title||Revealing Molecular-Level Interaction between a Polymeric Drug and Model Membrane Via Sum Frequency Generation and Microfluidics|
|Publication Type||Journal Article|
|Year of Publication||2020|
|Authors||Wang, C, Luo, Y, Li, X, Zhang, F, Wang, F, Han, X, Wang, T, Beke-Somfai, T, Lu, X|
Body ﬂuids ﬂow all over the body and aﬀect the biological processes at biointerfaces. To simulate such a case, sum frequency generation (SFG) vibrational spectroscopy and a selfdesigned microﬂuidic chip were combined together to investigate the interaction between a pH-responsive polymeric drug, poly(αpropylacrylic acid) (PPAAc), and the model cell membranes in diﬀerent liquid environments. By examining the SFG spectra under the static and ﬂowing conditions, the drug−membrane interaction was revealed comprehensively. The interfacial water layer was screened as the key factor aﬀecting the drug−membrane interaction. The interfacial water layer can prevent the side propyl groups on PPAAc from inserting into the model cell membrane but would be disrupted by numerous ions in buﬀer solutions. Without ﬂowing, at pH 6.6, the interaction between PPAAc and the model cell membrane was strongest; with ﬂowing, at pH 5.8, the interaction was strongest. Flowing was proven to substantially aﬀect the interaction between PPAAc and the model cell membranes, suggesting that the ﬂuid environment was of key signiﬁcance for biointerfaces. This work demonstrated that, by combining SFG and microﬂuidics, new information about the molecular-level interaction between macromolecules and the model cell membranes can be acquired, which cannot be obtained by collecting the normal static SFG spectra.