Tricalcium phosphate and tricalcium phosphate/polycaprolactone particulate composite for controlled release of protein

Abstract

β-Tricalcium phosphate (β-TCP) with three different particle size ranges was used to study the effects of particle size and surface area on protein adsorption and release. Polycaprolactone (PCL) coating was applied on the particle systems to investigate its effect on particulate systems properties from both structural and application aspects. The maximum loading of 27 mg/g was achieved for 100 nm particles. Bovine serum albumin (BSA) loading amount was controlled by varying the BSA loading solution concentration, as well as the sample powder’s surface area. Increasing the surface area of the delivery powder significantly increased loading and release yield. Unlike the samples with low surface area, the lowest particle size samples showed sigmoidal release profile. This indicated that release was governed by different mechanism for particles with different sizes. While the majority of samples showed no more than 50% release, the 550nm particles demonstrated 100% release. PCL-coating showed no significant ability to attenuate burst release in PBS. However, it led to a steadier release profile as compared to the bare TCP particles. FTIR analysis also proved that the secondary structure of BSA did not change significantly during the adsorption; however, minor denaturation was found during the release. The same results were found when PCL coating was applied on the TCP particles. We envision potential use of TCP and TCP+PCL systems in bone growth factor or orthopedic drug delivery applications in future bone tissue engineering application.

Phase stability and biological property evaluation of plasma sprayed hydroxyapatite coatings for orthopedic and dental applications

“…The difference in release kinetics from coating and particle system could be due to the difference in surface area between the two systems. In a particulate system, protein or other molecules are adsorbed (physisorbed or chemisorbed) on each particle with higher surface area compared to the coatings [24,27], as a result, higher released amount is expected with faster dissolution rate. In coatings, however, loading is performed only on the free particles of surface.…”

Optimization of Synthesis Parameters for the Production of Biphasic Calcium Phosphate Ceramics via Wet Precipitation and Sol‐Gel Process

“…WP_2 dried and WP_2 700 present a mixture of type II and IV isotherms according to the BDDT classification . The decrease in surface area between these samples can be explained by the presence of β‐TCP that is hardly porous . After 800 °C, the conversion of calcium‐deficient HA to β‐TCP reduces the porosity.…”

Effects of vitamin D3 release from 3D printed calcium phosphate scaffolds on osteoblast and osteoclast cell proliferation for bone tissue engineering

“…Minimal or eliminated burst release and prolonged release can be achieved using polymers such as PCL; a biodegradable polymer used to modulate release kinetics. [23][24][25][39][40][41] PCL is degradable through hydrolysis of the ester linkages which can occur in physiological conditions. 42 The hydrophobic properties of PCL limited the potentially higher burst release of vitamin D 3 and enabled a more controlled, prolonged release over time.…”