**5. Concluding Remarks**

In this review, the current state of research on collagen extracted from the ECM of invertebrates and its applications in the medical field have been discussed, and some light has been shed on future perspectives of this important marine material. The methodological issues of collagen purification from invertebrates, which the researchers are currently struggling with, have also been highlighted. The discussion concerning the purification techniques in this review could be of tremendous help in the extraction of purified collagen from invertebrates. The extracellular matrix, which is one of the key components in invertebrates and is responsible for producing collagen in this marine group, has been elaborated with informative imaging. In addition, the glycosylation activity with the formation of glycoproteins (size of the protein, which varies from species to species) in invertebrates, whose biological processes are involved in producing collagen, has been discussed for the first time in this review. The obtained results demonstrate the potential for marine invertebrates to generate new drugs, especially for bone tissue regeneration.

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

### **References**


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