Bone tissue substitutes are increasing in importance. Hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) act as a cell matrix and improve its mechanical properties. One of their raw materials is marine-origin by-products. Objectives: To synthesize, characterize, and evaluate the cellular cytotoxicity of a 3D biomaterial based on HA and β-TCP from mussel shells. Methods: We prepared pellets with 150, 200, and 250 mg and evaluated them through sintering, XRD, FTIR, ICP-OES, Scanning Electron Microscopic (SEM), and immunocytochemical tests. The Alamar Blue method was applied to the Balb-T3T cell line within 72 h to evaluate cytotoxicity. Results: Our biomaterials presented a smooth surface with slight irregularity and porosities presenting different diameters and morphologies and showed chemical, morphological, and ultrastructural similarity to bone hydroxyapatite, mainly the 150 and 200 mg pellets. Significance: We produced promising HA/β-TCP bioceramics with characteristics that allowed cell culture, promoting adhesion, spreading, and proliferation.

Melanoma is a highly metastatic and rapidly progressing cancer, a leading cause of mortality among skin cancers. The melanoma microenvironment, formed from the activity of malignant cells on the extracellular matrix and the recruitment of immune cells, plays an active role in the development of drug resistance and tumor recurrence, which are clinical challenges in cancer treatment. These tumoral metabolic processes are affected by proteins, including Galectin-3 (Gal-3), which is extensively involved in cancer development. Previously, we characterized a partially methylated mannogalactan (MG-Pe) with antimelanoma activities. In vivo models of melanoma were used to observe MG-Pe effects in survival, spontaneous, and experimental metastases and in tissue oxidative stress. Analytical assays for the molecular interaction of MG-Pe and Gal-3 were performed using a quartz crystal microbalance, atomic force microscopy, and contact angle tensiometer. MG-Pe exhibits an additive effect when administered together with the chemotherapeutic agent dacarbazine, leading to increased survival of treated mice, metastases reduction, and the modulation of oxidative stress. MG-Pe binds to galectin-3. Furthermore, MG-Pe antitumor effects were substantially reduced in Gal-3/KO mice. Our results showed that the novel Gal-3 ligand, MG-Pe, has both antitumor and antimetastatic effects, alone or in combination with chemotherapy.