Waiting for Aπαταω: 250 Years Later

Mechanism of formation governs the mechanism of release of antibiotics from calcium phosphate nanopowders and cements in a drug-dependent manner

“…A number of properties of HAp justify its use as a drug delivery agent, and they include: (i) exceptional biocompatibility and bioactivity; (ii) excellent sorption capacity, (iii) the ability to bind both negatively and positively charged drugs through electrostatic interaction with Ca 2+ and PO 4 3− ions, respectively, and also engage in hydrogen bonding mediated by the OH − group; (iv) sparse solubility (~0.3 μg ml −1 ) and relatively long biodegradation times, which facilitate diffusion-controlled drug release kinetics; (v) the capability to capture drugs inside micropores formed within ultrafine particle aggregates, thus preventing the burst release and ensuring sustained release profiles; (vi) the propensity for accommodation of foreign ions that endow HAp with a range of electrical, magnetic, mechanical and optical properties not found in the pure compound, and others. 19,20 However, despite the fact that the first studies on HAp as a drug delivery carrier were done more than 30 years ago, [21][22][23] in the 1980s, meager progress has been made in the direction of allowing the release profiles in pure HAp ceramics to be tuned using sets of easily controllable structural parameters. It is hoped that a deeper understanding of the mechanism of release of drugs from HAp may bring the scientific community closer to the accomplishment of this vital practical goal.…”

When Nothing Turns Itself Inside out and Becomes Something: Coating Poly(Lactic-Co-Glycolic Acid) Spheres with Hydroxyapatite Nanoparticles vs. the Other Way Around

“…Nanoparticles that this nanocomposite comprised were composed of hydroxyapatite (HAp), the synthetic version of the inorganic crystalline component of mammalian bones and teeth. Although traditionally used as a filler for bone defects because of its chemical and crystallographic similarity to biogenic apatite, the application repertoire of HAp has been continually expanding over the past years and decades [ 3 ]. In the late 1970s, the first studies on loading HAp with organic molecules and measuring their release were reported [ 4 , 5 ] but, as ever [ 6 ], it would take a couple of decades before the interest in the use of HAp as a drug delivery vehicle would become mainstream [ 7 ].…”

Sic Parvis Magna: Manganese-Substituted Tricalcium Phosphate and Its Biophysical Properties

“…The importance of calcium phosphates (CPs) for the discipline of biomedical engineering cannot be done justice to in simple wording. These are materials that have steadily been at the forefront of the interest of the scientific community for the last 100 years, specifically since the first synthetic CP was implanted in an animal, in 1920. , The chemical versatility of CPs ensures that the forms in which they are synthesized and applied do not get depleted. One of the ways in which this versatility is pursued is through amending CPs with various elements of the periodic table that are not native to its structure.…”