Abstract
Based on the formation of carbodiimide compounds between carboxyl and primary amines, hollow microspheres arising from the folic acid (folate-FA) grafted onto the surface of the modified hydroxyapatite were successfully prepared. The hollow morphology and composition of the FA-grafted hydroxyapatite microspheres were confirmed by scanning electron microscopy (SEM) and other characterizations. Brunauer-Emmett-Teller (BET) assay revealed the specific surface area and average pore size of the microspheres were 34.58m2/g and 17.80 nm, respectively. As a drug carrier, the kinetic investigation of doxorubicin (DOX) loaded shows that the adsorbed behavior of drug on the adsorbent is more suitable to be described with pseudo-first-order model. Furthermore, the release rate can reach 83% at pH 5.7, which is greater than the release of 39% at pH 7.4, indicating an excellent performance of controlled drug release for response pH. The release mechanism of DOX coincides with Fickian diffusion as a result of Korsmeyer-Peppas model analysis and the release phenomena can be well explained by Fickian diffusion second law.
Highlights
In recent years, hydroxyapatite has received great attention in tissue engineering and biomedical areas due to its similarity to the mineral component of bone tissues [1,2,3], excellent biocompatibility [4,5,6], and bioactivity as well as osteoconductive feature without causing local or systemic toxicity and inflammation [7, 8]
It is well known that folic acid is one of the receptor mediated targeting moieties [17,18,19] and its receptor shows an overexpression on the surfaces of cancer cells, such as breast, brain, kidney, and ovarian
A uniform spherical morphology can be clearly observed, and some broken shapes with hollow interior indicate that the as-prepared microspheres have a porous hollow structure, and the average diameters are around 2.0 μm
Summary
Hydroxyapatite has received great attention in tissue engineering and biomedical areas due to its similarity to the mineral component of bone tissues [1,2,3], excellent biocompatibility [4,5,6], and bioactivity as well as osteoconductive feature without causing local or systemic toxicity and inflammation [7, 8]. As for the applications of biological medicine fields, the hydroxyapatite has been extensively investigated as control-released carriers of drug, such as antibiotics [9,10,11], 5-flurouracil [12], and protein drugs [13, 14]. In order to overcome these issues and improve therapeutic efficacy, many researchers have focused on such a kind of explorations to modify hydroxyapatite particles with specific ligands as a drug control-released carriers. The hydroxyapatite can be either functionalized by polyethylene glycol (PEG) in advance or directly functionalized with folic acid [21] or aminated folic acid [22], and the relevant assessments showed that these modified microparticles could be a great candidate for biomedical application. The microparticles mentioned above do not possess the hollow morphology that has been noticed
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
