Hydroxyapatite Nanoparticles in Drug Delivery: Physicochemistry and Applications

Abstract

Hydroxyapatite (HAP) has been the gold standard in the biomedical field due to its composition and similarity to human bone. Properties such as shape, size, morphology, and ionic substitution can be tailored through the use of different synthesis techniques and compounds. Regardless of the ability to determine its physicochemical properties, a conclusion for the correlation with the biological response it is yet to be found. Hence, a special focus on the most desirable properties for an appropriate biological response needs to be addressed. This review provides an overview of the fundamental properties of hydroxyapatite nanoparticles and the characterization of physicochemical properties involved in their biological response and role as a drug delivery system. A summary of the main chemical properties and applications of hydroxyapatite, the advantages of using nanoparticles, and the influence of shape, size, functional group, morphology, and crystalline phase in the biological response is presented. A special emphasis was placed on the analysis of chemical and physical interactions of the nanoparticles and the cargo, which was explained through the use of spectroscopic and physical techniques such as FTIR, Raman, XRD, SEM, DLS, and BET. We discuss the properties tailored for hydroxyapatite nanoparticles for a specific biomolecule based on the compilation of studies performed on proteins, peptides, drugs, and genetic material.

Composites Containing Nanohydroxyapatites and a Stable TEMPO Radical: Preparation and Characterization Using Spectrophotometry, EPR and 1H MAS NMR

“…The biological responses of hydroxyapatites and their effectiveness as drug delivery systems are highly dependent on their physicochemical properties, such as their crystal shape, size, morphology and functional groups [ 8 ]. The key to understanding and predicting physicochemical and biological properties of nanocrystalline hydroxyapatites lies in the composition of their hydrated surface layer.…”

Hard, Soft, and Hard-and-Soft Drug Delivery Carriers Based on CaCO3 and Alginate Biomaterials: Synthesis, Properties, Pharmaceutical Applications

“…As one of the bone components, HA has been applied in biomaterial science and tissue engineering due to its biocompatibility and potential medical therapeutic avenues, whereas it is still necessary to understand how HA nanoparticles interact with a biological environment (cell, tissue, organ, or system). And it is important that they will not be just thought of as a structure that will be accumulated, internalized, or used to deliver a cargo, but a construct that will directly or indirectly modulate cell signaling pathways to improve or worsen a specific function, through the cell/HA functional groups contained in both [ 14 ].…”

Nanometric Hydroxyapatite Particles as Active Ingredient for Bioinks: A Review

“…Indeed, the bioceramics which rapidly stimulate osteointegration and bone tissue generation are those that imitate the composition and structure of the bone mineral. In this regard, it has been demonstrated that ceramic biomaterials produced from HA nanoparticles show an improved resorbability and enhanced bioactivity than ceramics of micrometre range size [11,12]. The liberation of calcium ions from HA nanoparticles is comparable to that from apatite of biological origin and integrates more rapidly with tissues than that from rough crystals.…”