Higher cellular interaction and faster production of natural rubber latex LbL films by spraying method

Natural rubber latex (NRL) from Hevea brasiliensis can accelerate wound healing, but membranes made of NRL have shown low cellular interaction limiting their application as implants. By employing dipping layer-by-layer (LbL) technique, we were previously able to glow human fibroblast cells on NRL films. But this method is time consuming which hinders industrialization. Therefore, NRL films were produced using polyethyleneimine (PEI) by spraying (sp) LbL method, which proved to be 10 times faster than dipping techniques. Rinsed and non-rinsed sp films were produced by triggering the spray devices five times for each material. Both (PEI/NRL) 5 and (PEI/NRL) 15 spraying and dipping films were then analyzed by UV-vis, AFM, and contact angle measurements. In order to evaluate the cellular interaction, Vero cells were directly cultivated on the LbL films up to 24 h. Results showed that despite non-rinsed sp films having lower amount of material than dipping ones, Vero cells adhere similarly on both. Rinsed (PEI/NRL) 5 sp films, on the other hand, presented higher amount of cellular attachment as well as smaller NRL particles on the films’ surface. Thus, it was possible to increase cellular interaction of NRL and produce films 10 times faster by employing spraying LbL method.