**8. Conclusions**

In this review, five natural biocompatible and biodegradable polymer-based nanoparticles have been critically examined for therapeutic applications. The nanoformulations are superior to macro or conventional drug delivery systems, and they can maximize dosing frequency. They can target infected areas, organs, tumor sites, and tissues in the body. Biodegradable and biocompatible polymers are appropriate materials for the development of novel drug delivery systems. Biocompatibility, mechanical properties, and low cytotoxic effects of these polymers make them an appropriate choice for drug delivery systems. It is the need of time to manipulate the system, which reduces the toxic effects of drugs on healthy organs or body parts. Still, there is room to explore more biodegradable polymers for innovative biomedical applications. With increased progress in nanotechnology, we expect progress

in the area of therapeutic systems based on the development of modified nanomedicines for the proper treatment of diseases.

**Funding:** This research was supported by Economic and Social Research Council UK (ES/S000208/1).

**Conflicts of Interest:** The authors declare no conflict of interest.
