Organic Phosphorous and Calcium Source Induce the Synthesis of Yolk-Shell Structured Microspheres of Calcium Phosphate with High-Specific Surface Area: Application in HEL Adsorption

Abstract

Yolk-shell-structured calcium phosphate microspheres have a great potential for medical applications due to their excellent physicochemical properties and biocompatibility. However, developing a yolk-shell-structured calcium phosphate with high adsorption capability remains a challenge. Herein, a porous yolk-shell-structured microsphere (ATP-CG) of calcium phosphate with high-specific surface area [S BET = 143 m 2 g −1 , which is approximately three times as high as that of ATP-CL microspheres synthesized by replacing calcium source with calcium L-lactate pentahydrate (CL)] was successfully synthesized by using adenosine 5'-triphosphate disodium salt (ATP) as the phosphorous source and calcium gluconate monohydrate (CG) as calcium source through a self-templating approache. The influences of molar ratio of Ca to P (Ca/P), hydrothermal temperature, and time on the morphology of ATP-CG microspheres were also investigated. It is found that the organic calcium source and organic phosphorous source play a vital role in the formation of yolk-shell structure. Furthermore, a batch of adsorption experiments were investigated to illuminate the adsorption mechanism of two kinds of yolk-shell-structured microspheres synthesized with different calcium sources. The results show that the adsorption capacity of ATP-CG microspheres (332 ± 36 mg/g) is about twice higher than that of ATP-CL microspheres (176 ± 33 mg/g). Moreover, the higher-specific surface area caused by the calcium source and unique surface chemical properties for ATP-CG microspheres play an important role in the improvement of HEL adsorption capability. The study indicates that the as-prepared yolk-shell-structured microsphere is promising for application in drug delivery fields and provides an effective approach for improving drug adsorption capability.

Amorphous Precursor‐Mediated Calcium Phosphate Coatings with Tunable Microstructures for Customized Bone Implants

“…[ 36 ] The specific surface areas of the coatings were measured via mercury intrusion experiments to quantitatively explain the degradation rate sequence. [ 37 ] The largest volume of mercury intrusion was found in the fHAP coating (0.0181 mL), followed by the cHAP coating (0.0057 mL), the cCaP coating (0.0033 mL), and the tHAP coating (0.0024 mL). This sequence was in good agreement with that of the degradation rates (Figure 2C).…”

Guidelines derived from biomineralized tissues for design and construction of high-performance biomimetic materials: from weak to strong

“…Phosphorus-containing biomolecules can regulate the mineralization process. 516 Various phosphorus-containing biomolecules were used as the organic phosphorus sources in the synthesis of a variety of calcium (or This journal is © The Royal Society of Chemistry 2024 other metal) phosphate nanostructured materials with various morphologies, including adenosine 5 0 -triphosphate, 325,[517][518][519][520][521][522][523][524][525] adenosine 5 0 -diphosphate, 526 adenosine 5 0 -monophosphate, 527 creatine phosphate, [528][529][530] cytidine-5 0 -triphosphate, 531 pyridoxal-5 0phosphate, 532,533 fructose 1,6-bisphosphate, 326,534,535 b-glycerophosphate, 536 riboflavin-5 0 -phosphate 537 and phosphoserine. 538 Conventional syntheses of calcium phosphate materials are usually realized by the direct reactions of inorganic calcium salts and inorganic phosphates in solution.…”

The advances in nanomedicine for bone and cartilage repair

“…Calcium phosphate (CaP) materials are highly similar to the mineral composition of bone tissue with excellent biocompatibility and osteoconductivity, which have been widely used in bone tissue engineering [ 62 , 63 ]. In recent years, researchers have found that CaP NPs possess controllable particle size [ 64 ], high specific surface area [ 65 ], mild preparation conditions [ 64 ] and pH responsiveness [ 66 ], allowing most drugs to be adsorbed via ionic crosslinking or hydrogen bonding [ 67 , 68 ], with the potential as delivery systems for bone repair therapy. For example, Zhou et al prepared HA nanospheres with high specific surface area, which significantly improved the loading efficiency of bone morphogenetic protein-2 (BMP-2) and effectively reduced its initial burst release.…”