Controlled release of gentamicin from biomimetic calcium phosphate in vitro. Comparison of four different incorporation methods

Abstract

Cylinders of biomimetic (nanocrystalline) calcium phosphate were loaded with gentamicin by four different methods: 1) dip-coating, 2) impregnation followed by cold-isostatic pressing, 3) co-precipitation followed by cold-isostatic pressing, and 4) coating of coprecipitated particles with a biodegradable polymer PDLLA (poly-D,L-lactide), followed by uniaxial pressing. The release kinetics were studied in vitro over 10 days. The incorporation by methods 2), 3) and 4) showed a significantly higher long-term release of active gentamicin than dip-coating, although there was an initial burst during the first two days with all four methods. With method 4), there was an increase of the released gentamicin after 7 days, and the long-term release was the highest of these four methods. The results are of considerable interest for the preparation of biodegradable bone implants which are loaded with biologically active substances.

Calcium Phosphate Nanoparticles for Therapeutic Applications in Bone Regeneration

“…Bisso et al used a similar approach for the dual delivery of bisphosphates and nucleic acids [37]. Therapeutic factors can be loaded onto calcium phosphate particles either during the synthesis of the calcium phosphate through co-precipitation [38,39,40] or by combining with the calcium phosphate powders post-synthesis through absorption processes [36]. Co-precipitation can achieve strong chemical interactions between the therapeutic factor and calcium phosphate.…”

Selfprotective smart orthopedic implants

“…In recent years, some efforts have been made to coat the surface of the implant with antibiotics or a material with antibacterial properties such as silver [86,87]. The rationale for this approach is that the antibiotic in the coating or the material on the surface of the implant serves to prevent bacterial attachment and subsequent infection [88].…”

Effect of Disordered Structure of Boron-Containing Calcium Phosphates on their In Vitro Biodegradability

“…C alcium phosphate (CaP) ceramics, such as hydroxyapatite (HAp), tricalcium phosphate (TCP), and biphasic CaPs (mixtures of HAp and β‐TCP), are clinically available synthetic bone substitutes 1,2 . CaP particles serve as carriers for controlled protein release for bone regeneration, 3 biodegradable bone implants, 4 and are also used for cell transfection in biochemical applications 5 . The rate of protein release from HAp particles directly depends on the HAp dissolution rate, 4 when the equilibrium of the protein release is not very effective.…”

“…CaP particles serve as carriers for controlled protein release for bone regeneration, 3 biodegradable bone implants, 4 and are also used for cell transfection in biochemical applications 5 . The rate of protein release from HAp particles directly depends on the HAp dissolution rate, 4 when the equilibrium of the protein release is not very effective. If the rate of degradation of those CaP ceramics is faster than the rate of tissue regeneration, they cannot be used as bone substitutes.…”