Preparation and drug-delivery study of functionalized hydroxyapatite based on natural polysaccharide gums with excellent drug-loading properties

Abstract

In the work, a large number of polysaccharide-based functional groups have been introduced into hydroxyapatite (HAP) by one-step synthesis to obtain HAP materials with high drug-loading properties. HAP materials have attracted much attention in various biomedical fields due to their excellent biocompatibility. Natural polysaccharides are long-chain polymer compounds with abundant hydrophilic groups. They are widely used in biomedical materials because of their nontoxicity, biocompatibility and biodegradability. In this study, HAP materials containing more than 20% of organic matter have been successfully synthesized by using Ca(NO3)2·4H2O and NH4H2PO4 as raw materials based on two natural polysaccharide gums (tamarind seed polysaccharide gum and guar gum (GG)). The results of X-ray diffractometer, thermogravimetric analyzer, Fourier transformed infrared spectrophotometer (FTIR) show that the functional groups of galactomannan gum have been successfully introduced into the HAP materials with the maximum mass content of 23%. The cytotoxicity tests of HAP materials show that the cell viability is constantly higher than 95%, indicating that functionalized HAP materials have good biocompatibility. HAP material modified by GG has a high drug-loading capacity of 236.18 mg g−1 and a drug loading efficiency of up to 74.79%. The obtained materials also have a pH-responsive release property, and the targeted drug-releasing rate is about 25% in vitro environment of pH 7.4 and 5.0. The results indicate that HAP materials functionalized by GG have a potential application in targeted drug delivery.