5. Conclusions

Despite all this, CS-based PDDS has already achieved considerable success in the past decades. It is believed that in the near future, with the rapid development of material science, biotechnology, genetic engineering, medical technology, and other scientific fields, people will have a more extensive and in-depth understanding of the unique properties of CS and its derivatives. We hope that more efficient CSbased PDDS will be designed, by developing novel material preparation strategies, advanced formulation methods, and improved inhalation technology. We believe that CS-based PDDS will play more important roles in the applications of local and systemic disease treatment in the near future.
