Hi Gaurav,

Protein molecules could be coated through hydrophobic interaction (which is usually favourable due to high surface hydrophobicity on latex beads). In that case, you may follow some protocols described in the attached link.

http://www.cyto.purdue.edu/cdroms/cyto4/7_spon/bangs/13a.pdf

Hi Gaurav,

You can adopt the layer-by-layer technique to coat the latex polystyrene beads with collagen. It is a non complex technique, easy to perform, the parameters are also quite versatile and does not require expensive equipments. By tailoring the pH (to acid) of collagen solution, this protein becomes positively charged and you can directly interact with your particles which are negatively charged (http://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma/Product_Information_Sheet/2/lb8pis.pdf). If the surface is neutral in charge you can also make a fast modification with ethylenediamine and the microparticles surfaces will become positively charged and so you can use hyaluronic acid (negatively charged) to interact with collagen, for example.

In this way we can have control over coating thickness, which can be further determined using the Quartz crystal microbalance, and consequently you can control particle size.

Enclosed you can find an example of the suggested technique.

Hope I was helpful!

Warm regards,

Daniela