Nanobiotechnology for health-care

The Zero-order kinetic of Ceftriaxone release from microwave-induced Octacalcium phosphate–Chitosan hybrid composite
Kumeda M.O.1, Sukhodub L.B.1, Sukhodub L.F.1
1 Sumy State University. 2, Rymskogo-Korsakova st., 40007 Sumy,Ukraine. 
E-mail: m.kumeda@med.sumdu.edu.ua

Demand for bone replacement therapy has been growing worldwide in recent decades. The creation of new variations of materials that can best mimic the properties of native bone remains relevant. Studies have shown that calcium phosphates (CaP), as well as composite and hybrid materials based on them with the inclusion of synthetic and natural polymers, are highly effective materials for repairing the damaged bone.
Octacalcium phosphate (OCP, Ca8(HPO4)2(PO4)4 ·5H2O), which is a precursor of biological apatite crystals due to the peculiarities of its structure, occupies a special place among CaP. It has alternating layers of apatite parallel to the plane (100) and hydrated layers. OCP can self-transform both in vitro and in vivo in hydroxyapatite (HA) as a more thermodynamically stable phase [1]. The value of the Solubility Constant OCP (-log Ks = 96.6) lies between stoichiometric HA (log (Ks) = 116.8) and calcium-deficient HA (-log (Ks) = 85). Consisting of the "water" and "apatite" layers, which include HPO42− ions, ОСР has a higher affinity for organic molecules than other CaPs due to the relatively empty hydrated layer, where the attachment of various ions and molecules is most likely [2]. Among biomolecules, chitosan (CS) is a linear copolymer of glucosamine and acetyl glucosamine usually is obtained by the deacetylation of chitin, an abundant polysaccharide mainly extracted from crustacean cuticles.  The combination of these components in one hybrid material with incorporated molecules of the antibiotic Ceftriaxone when using microwave irradiation during the synthesis, made it possible to create a hybrid material that avoids the explosive release of Ceftriaxone from the material and achieve the zero-order kinetics of its release.

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