Epithelial cell adhesion molecule (EpCAM) binding short peptides derived from antibody MOC-31; De-novo design, synthesis and their in-vitro evaluation.

Epithelial cell adhesion molecule (EpCAM) is one of the critical bio-maker for circulating tumor cells (CTC) detection. For capturing CTC, antibody-antigen-based techniques have mainly been explored. However, the expensiveness and tedious manufacturing process have posed certain limitations for antibody-based techniques for its wide applications in cell capturing. On the other hand, peptides are inexpensive bimolecular probes with high specificity and tunability. Although there are few reports on EpCAM binding peptides are available in literature, those peptides were selected through random library screening. Interestingly, de-novo design of the peptides against EpCAM has not been reported till date. For the first time, we have developed a small peptide (Pep14) from the complementary derived region (CDRs) of antibody MOC31 through systematic virtual screening. Selected peptide has demonstrated good binding affinity towards EpCAM with dissociation constant (Kd) of 870 nM and found to be co-localized with the anti-EpCAM antibody in EpCAM expressing cancer cells (MCF-7). Therefore, the short peptide Pep14 hold promise for capturing circulatory tumor cells through EpCAM binding.

Peptide-Chitosan Engineered Scaffolds for Biomedical Applications.

Peptides are signaling epitopes that control many vital biological events. Increased specificity, synthetic feasibility with concomitant lack of toxicity, and immunogenicity make this emerging class of biomolecules suitable for different applications including therapeutics, diagnostics, and biomedical engineering. Further, chitosan, a naturally occurring linear polymer composed of d-glucosamine and N-acetyl-d-glucosamine units, possesses anti-microbial, muco-adhesive, and hemostatic properties along with excellent biocompatibility. As a result, chitosan finds application in drug/gene delivery, tissue engineering, and bioimaging. Despite these applications, chitosan demonstrates limited cell adhesion and lacks biosignaling. Therefore, peptide-chitosan hybrids have emerged as a new class of biomaterial with improved biosignaling properties and cell adhesion properties. As a result, recent studies encompass increased application of peptide-chitosan hybrids as composites or conjugates in drug delivery, cell therapy, and tissue engineering and as anti-microbial material. This review discusses the recent investigations involving chitosan-peptide materials and uncovers various aspects of these interesting hybrid materials for biomedical applications.