Reinforcement and characterization of biopolymer-rhamnolipid nanoparticles: Biocompatibility, in-vitro stability, physico-chemical, rheological and bioactive properties

In the present study, biopolymer (chitosan and alginate)-reinforced rhamnolipid nanoparticles were prepared and represented as 'ALG-RHLP-NPs' and 'CHI-RHLP-NPs'. The sizes of the nanoparticles ranged from 150 to 300 nm. The encapsulation efficiencies of ALG-RHLP-NPs and CHI-RHLP-NPs were found to be 81.1 % and 90.2 %, whereas the loading capacities were in the range of 42-50 %. The estimated particle size of the reinforced nanoparticle suspensions was correlated well with predicted particle size as exhibited by partial least squares regression (PLSR) model. The second derivative of the absorbance (Log 1/R) of the nanoparticle suspensions showed that the reinforcement of rhamnolipid nanoparticles (RHLP-NPs) did not alter the molecular organization of the biopolymers. The synthesized ALG-RHLP-NPs and CHI-RHLP-NPs were found to have cracked and layered fractures as revealed by surface topography. In-vitro stability and rheological flow behavior revealed that the addition of RHLP-NPs to biopolymers has reduced aggregation and facilitated the production of uniform particles, and thereby improving the stability of synthesized nanoparticles via electrostatic interactions. Furthermore, the nanoparticle-reinforced membranes were found to be non-toxic and biocompatible as revealed by cytotoxicity study of L929 fibroblast cells. The results demonstrated that biopolymer-reinforced rhamnolipid nanoparticles have good potential for use in pharmaceutical, biomedical, and tissue engineering applications.