Insights on the properties of levofloxacin-adsorbed Sr- and Mg-doped calcium phosphate powders

Crystallization of carboplatin-loaded onto microporous calcium phosphate using high-vacuum method: Characterization and release study

Drug delivery systems are a new approach to increase therapeutic efficacy and to reduce the side effects of traditional treatments. Calcium phosphates (CaPs) have been studied as drug delivery systems, especially in bone diseases. However, each system has some particularities that depend on the physical and chemical characteristics of the biomaterials and drug interaction. In this work, granulated CaPs were used as a matrix for loading the anticancer drug carboplatin using the high-vacuum method. Five compositions were applied: hydroxyapatite (HA), β-tricalcium phosphate (β-TCP), biphasic HAp 60%/β-TCP 40% (BCP), β-TCP/MgO nanocomposite, and β-TCP/SiO2 nanocomposite. Carboplatin drug in 50, 60, and 70 mg/g was precipitated on the surface of CaPs. Morphological, chemical and surface modifications in the carboplatin-CaPs were investigated by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), backscattered electron microscopy (BSE), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), Fourier transform infrared (FT-IR), and Raman spectroscopy. The characterization of the CaP-carboplatin biomaterials showed heterogeneous crystalline precipitation of the drug, and no morphological modifications of the CaPs biomaterials. The in vitro release profile of carboplatin from CaPs was evaluated by the ultraviolet-visible (UV-Vis) method. The curves showed a burst release of upon 60% of carboplatin loaded followed by a slow-release of the drug for the time of the study. The results were typical of a low-interaction system and physisorption mechanism. The high-vacuum method permitted to load the high amount of carboplatin drug on the surface of the biomaterials despite the low interaction between carboplatin and CaPs.

Synthetic and Marine-Derived Porous Scaffolds for Bone Tissue Engineering

Bone is a vascularized and connective tissue. The cortical bone is the main part responsible for the support and protection of the remaining systems and organs of the body. The trabecular spongy bone serves as the storage of ions and bone marrow. As a dynamic tissue, bone is in a constant remodelling process to adapt to the mechanical demands and to repair small lesions that may occur. Nevertheless, due to the increased incidence of bone disorders, the need for bone grafts has been growing over the past decades and the development of an ideal bone graft with optimal properties remains a clinical challenge. This review addresses the bone properties (morphology, composition, and their repair and regeneration capacity) and puts the focus on the potential strategies for developing bone repair and regeneration materials. It describes the requirements for designing a suitable scaffold material, types of materials (polymers, ceramics, and composites), and techniques to obtain the porous structures (additive manufacturing techniques like robocasting or derived from marine skeletons) for bone tissue engineering applications. Overall, the main objective of this review is to gather the knowledge on the materials and methods used for the production of scaffolds for bone tissue engineering and to highlight the potential of natural porous structures such as marine skeletons as promising alternative bone graft substitute materials without any further mineralogical changes, or after partial or total transformation into calcium phosphate.