**8. Conclusion**

Proteins and peptides are essential in various biochemical processes. These are also involved in various pathophysiological conditions. Therefore, the application of proteins and peptides to combat diseases, including cancer and diabetes, will be beneficial. However, unfavorable physicochemical properties of protein and peptides such as large size, hydrophilicity, and stability limit their use. Various approaches (discussed in this chapter) have been developed to overcome these problems. However, there is no general strategy for the delivery of protein or peptide therapeutics. One reason for the absence of a general strategy is the complex nature and variety of peptides and proteins. Thus, many strategies discussed in this chapter were focused on the delivery of the protein or peptide of interest. The longterm safety and efficacy of all these strategies should be considered. So, there are challenges to overcome in delivering the protein or peptide therapeutics. However,

#### *Protein and Peptide Drug Delivery DOI: http://dx.doi.org/10.5772/intechopen.99608*

the future of protein and peptide delivery is bright considering the growing number of materials and combinatorial approaches. Also, emphasis is placed on developing cost-effective, tunable, biodegradable, and biocompatible materials for protein and peptide delivery. In the near future, it will be excellent to have a system that can be used for the delivery and systemic stability of different proteins and peptides.
