Calcium-Deficient Hydroxyapatite/Collagen/Platelet-Rich Plasma Scaffold with Controlled Release Function for Hard Tissue Regeneration.

Calcium phosphate cement scaffolds have been extensively used in bone tissue regeneration applications because they are similar to the inorganic components of bones and have outstanding biocompatibility. However, the main shortcomings of ceramic scaffolds are their brittleness and low retention level of various growth factors or drugs. To overcome these shortcomings, we have reinforced ceramic scaffolds using synthetic and natural polymers as composites. Here, we designed a new bone-biomimetic composite consisting of calcium deficient hydroxyapatite (CDHA), collagen, and plate-rich plasma (PRP) using low temperature printing process. In the biocomposite, we manipulated the release of the bioactive component, PRP, which has several growth factors, for a long culture period (up to 35 days) by using a polyphenol, tannic acid. The mesh-structured biocomposite showed structural stability. We also tested the in vitro biocompatibilities of the biocomposite using preosteoblasts (MC3T3-E1) and found that the biocomposite showed better cell growth and differentiation compared to the control (fabricated without PRP). Although effects of platelet-rich plasma have remained controversial, our results indicated controlled release of PRP with a biocomposite showed enhanced proliferation and differentiation of preosteoblast cells.