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

Abstract

Several types of biodegradable materials have been investigated for the treatment of osteomyelitis. Calcium phosphate (CaP) ceramics are among the most performing materials due to their resemblance to human hard tissues in terms of mineralogical composition, and proven ability to adsorb and deliver a number of drugs. This research work was intended to study the suitability of modified CaP powders loaded with a fluoroquinolone as drug delivery systems for osteomyelitis treatment. Levofloxacin (LEV) was chosen due to the well-recognized anti-staphylococcal activity and adequate penetration into osteoarticular tissues. Substituted CaP powders (5 mol% Sr(2+) or 5 mol% Mg(2+)) were synthesised through aqueous precipitation. The obtained powders were characterised by X-ray diffraction, SEM and FTIR analysis. The X-ray diffraction patterns confirmed the presence of HA and β-tricalcium phosphates (β-TCP) phases in doped compositions, especially in the case of Mg-doped system. The fixation of LEV at the surface of the particles occurred only by physisorption. Both the in vitro microbiological susceptibility, against Staphylococcus spp, and biocompatibility of LEV-loaded CaP powders have not been compromised.

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

“…Considering surface normalized drug loading, other factors, such as drug-matrix interaction and environmental conditions of drug loading, had more influence on the drug load capacity [4,87,88]. The profile release in this study was attributed to the low interaction between CaPs and carboplatin, as well as the drug concentration and vacuum method used to drug loading [24]. The fast initial release of platinum agents demonstrated anticancer efficacy in vitro and in vivo.…”

“…Additionally, the in vitro concentration verified in release tests cannot be extrapolated to an in vivo approach, especially for local delivery systems, due to the peculiarities of the biological or pathological environment. Nevertheless, release studies can provide an understanding of the release mechanism and drug/carrier interactions [4,21,24]. For example, the diffusion/dissolution model for non-uniform dispersed drug in non-swelling and non-degradable rigid polymer matrices was approached by Xiang and McHugh [82,83].…”

“…Several substances have been loading in CaP delivery systems: antibiotics and anti-inflammatories, to prevent and treat osteomyelitis [24][25][26][27]; drugs and hormones, to improve the bone remodeling process [7,28]; genetic material [29,30]; and therapeutic drugs, in cancer disease [22,31,32]. Cancer treatment usually involves undesirable side effects.…”

Synthetic and Marine-Derived Porous Bone Graft Substitutes

“…It is recognized that the introductions of ions like strontium (Sr) [93][94][95][96], magnesium (Mg) [94,96], manganese (Mn) [7,95,96] or zinc [97,98] in a single or combined way play a fundamental role in bone development. Sr is present in bone in considerable amounts and, in particular at regions of elevated metabolic turnover [92,96].…”

“…Sr is present in bone in considerable amounts and, in particular at regions of elevated metabolic turnover [92,96]. Its presence is associated with the increase of osteoclast apoptosis and the enhance of osteoblastic cell proliferation and collagen synthesis, which subsequently maintain the bone formation and inhibit bone formation [93,94]. Mg is related with mineralization of calcified tissue, its amount starts to be higher and decrease during the calcification process.…”