Osteoblast-Adhesive Peptide, a polypeptide designed for biomaterials' chemical modification, enhances osteoblast adhesion, showing promise for use in dentistry and orthopedics [1] [2].

Kisspeptin-10, human TFA is a potent vasoconstrictor and angiogenesis inhibitor. Kisspeptin-10, human TFA acts as a tumor metastasis suppressor via its receptor GPR54. Kisspeptin-10-GPR54 system plays an important role in embryonic kidney development. Kisspeptin-10/GPR54 signaling induces osteoblast differentiation via NFATc4-mediated BMP2 expression

Muramyl dipeptide (MDP) is a synthetic immunoreactive peptide, consisting of N-acetyl muramic acid attached to a short amino acid chain of L-Ala-D-isoGln. Muramyl dipeptide indirectly decreases osteoclast differentiation through a decreased RANKL/OPG ratio. Muramyl dipeptide directly increases osteoblast differentiation by up-regulating Runx2 gene expression through MAPK pathways. Muramyl dipeptide is an inducer of bone formation through the induction of Runx2 .

N-Oleoyl-L-Serine (N-Oleoylserine) is an endogenous long-chain fatty acid amide that is a lipid modulator of bone remodeling and stimulates osteoclast apoptosis which can be used to study osteoporosis. N-Oleoyl-L-Serine showed high activity in an osteoblast proliferation assay.N-Oleoyl-L-Serine promotes osteoclast apoptosis by inhibiting Erk1 2 phosphorylation and expression of nuclear κB ligand (RANKL) receptor activator in bone marrow stromal cells and osteoblasts, which attenuates osteoclast populations.

Osteocalcin (1-49) is a non-collagenous peptide that is secreted by osteoblasts and odontoblasts and comprises 1-2% of the total protein in bone. Secretion of osteocalcin (1-49) is stimulated by 1,25-dihydroxy vitamin D and plasma levels increase in diseases that induce dysregulated bone turnover such as osteoporosis, Paget's disease, and primary hyperparathyroidism. Osteocalcin (1-49) is positively correlated with insulin sensitivity and negatively correlated with high blood glucose levels in women. In vitro, osteocalcin induces chemotaxis of MDA-MB-231 breast cancer cells, human peripheral blood monocytes, and rat osteosarcoma cells with osteoblast-like characteristics. It is also expressed by vascular smooth muscle cells (VSMCs) displaying an osteoblast-like phenotype and has been positively associated with calcification of aortic tissue and heart valves in humans.

Kisspeptin-10, human TFA, is a potent vasoconstrictor and angiogenesis inhibitor that also suppresses tumor metastasis through its interaction with the receptor GPR54. It is crucial for embryonic kidney development and promotes osteoblast differentiation through NFATc4-mediated BMP2 expression via the Kisspeptin-10/GPR54 signaling pathway [1].

VnP-16, a synthetic peptide fragment mirroring amino acids 270-281 of vitronectin (a multifunctional glycoprotein involved in cell attachment, migration, and spreading), promotes attachment and spreading of isolated human osteogenic cells. This effect is reversible with β1 integrin siRNA knockdown when VnP-16 is applied at 9.1 µg/cm2 on cell plates. The compound enhances osteogenesis in human skin-derived mesenchymal precursors and MC3T3-E1 mouse calvarial osteoblast precursors. Furthermore, in vivo studies show VnP-16 mitigates IL-1α-induced bone loss, reduces calvarial osteoclast numbers in mice, increases bone mineral density, and lessens trabecular bone loss in a mouse model of ovariectomy-induced bone loss.