Chitosan nanoparticles are biodegradable, biocomptible and non-toxic polymer with several applications in drug delivery, tissue engineering and wound healing.

You might find these links useful:-

https://www.researchgate.net/project/Chitosan-nanoparticles-as-a-biodegradable-and-biocompatible-drug-delivery-system.

https://www.sciencedirect.com/science/article/pii/S1021949814001410/pdfft?md5=3dc38497b62d52ed469cd02e30afd7c8&pid=1-s2.0-S1021949814001410-main.pdf

Generally speaking positive charge and biocompatibilty are at odds with one another. At neutral pH's then most naturally occurring entities in the body, for example, are negatively charged. As such antibodies typically react against positively charged species. This is why we need special techniques such as stealth liposomes (cover the particles with a steric protection layer of PEG, for example) are utilized to get such systems past the barriers.

Chitosan, poly(amino esters), polylysine and stumili-responsive polymers are all positive biodegradable polymeric nanoparticles.

You can read these articles:

https://www.nature.com/articles/natrevmats201675

Article Semi‐Automated Synthesis and Screening of a Large Library of...

Chitosan, Guar gum and Gum acacia are positively charged biopolymers with biodegradable, biocompatible properties