It is almost impossible to synthesize a new protein by using ready-made short peptides in human body with the current cognitive level of subject development. We can see that the normal way of protein synthesis is the result of mRNA translation. There is only AA in this process, and there is no short peptide.

The only possible addition is protein shearing and modification in the post-translation modification process, the famous one is ubiquitination, and there is a similar method to label protein, but I forgot specifically ... The problem is that it is not a short peptide, and it is not used to synthesize protein's short peptide. Collagen has a large number of amino acid residues that are repeated and modified by three units. There is still hope to do it in vitro, but in vivo it is synthesized purely by reverse engineering hydrolysis of the brain.