Antibiotic-loaded poly-ε-caprolactone and porous β-tricalcium phosphate composite for treating osteomyelitis

Bone tissue engineering: A review in bone biomimetics and drug delivery strategies

“…Although this technique has advanced the overall science of controlled drug delivery in tissue engineering, unintended release of residual solvent trapped in the polymer after processing is harmful to adherent cells, local growth factors, and neighboring tissue. 221,[313][314][315][316][317][318] Residual organic solvents in a polymer scaffold limit or prevent the encapsulation of active growth factors and hence functionality of the scaffold. Therefore, novel solvent-free techniques are being aggressively pursed.…”

Bone tissue engineering therapeutics: controlled drug delivery in three-dimensional scaffolds

“…In vitro, BGs are able to form a surface layer of (2002) foaming (i) effervescent salts (ammonium bicarbonate) are used as porogens and mixed with an organic viscous solution/suspension of polymer/ceramic (ii) after solvent evaporation, porosity is achieved by placing scaffolds into hot water or an aqueous solution of citric acid to dissolve the salts (iii) an alternative is CO 2 -based gas Mooney et al (1996); Harris et al (1998) template technique (i) scaffolds are prepared by dipping a polyurethane sponge into a slurry of proper viscosity containing ceramic particles (ii) the impregnation step and the removal of the surplus slurry should be adjusted to obtain, after the sponge removal, a defect-free porous three-dimensional scaffold (iii) sometimes, in order to obtain mesoporous structures, surfactants may be added Vitale- Chen, Q. Z. et al (2006) sol-gel (i) scaffolds are prepared by dissolving inorganic metal salts or metal organic compounds in a solvent where a series of hydrolysis and polymerization reactions allow the formation of a colloidal suspension ('sol') (ii) after casting the 'sol' into a mould, a wet 'gel' is formed (iii) with further drying and heat treatment, the 'gel' is converted into dense ceramic or glass articles Domingues et al (2004) powder compaction (i) scaffolds are prepared by compressing the polymers/ ceramics using projectiles or punch and dies (ii) the velocity of compaction of the projectile or punch and dies is adjusted to achieve powder consolidation and the desired porosity (iii) the process can include sintering (iv) an alternative is to use uniaxial or isostatic pressing Miyai et al (2008) microcrystalline HA when in contact with simulated body fluid (SBF) (Kim et al 1995;Hench 1998;Fujibayashi et al 2003). More recently, it has been discovered that ionic dissolution products released from silica-based BGs upregulate seven families of genes found in osteoblasts (Xynos et al 2001).…”

“…GFLX mostly retained its bactericidal property after processing. In vitro testing in Hanks' balanced solution showed that the composite of GFLX-loaded PCL/ bTCP ceramic released GFLX for four weeks and had sustained bactericidal activity against S. milleri and Bacteroides fragilis for at least one week (Miyai et al 2008). In vivo tests in rabbits with osteomyelitis lesions induced by S. milleri and B. fragilis in the rabbit mandible showed that the composite of GFLX-loaded PCL/ xTCP was effective in controlling infection at the bone defect formed by debridement.…”

“…Further, after 50 weeks, ingrowing bone tissue with vascular vessels was observed along the PCL and b-TCP interface. Additionally, GFLX concentrations in the serum and soft tissues were very low suggesting a low risk of systemic toxicity (Miyai et al 2008). Ciprofloxacin (CFX) is the most widely used fluoroquinolone for bacterial bone infection with a low MIC (0.25 -2 mg ml 21 ).…”

Calcium orthophosphate-based biocomposites and hybrid biomaterials

“…PCL/b-TCP biocomposites were developed as well [398][399][400][401] and their in vitro degradation behavior was systematically monitored by immersion in simulated body fluid at 37°C [400]. To extend this topic further, the PCL/b-TCP biocomposites might be loaded by drugs [401].…”