RESUMEN

Calcium plays an important role in barrier function repair and skin homeostasis. In particular, calcium phosphates (CaPs) are well established materials for biomedical engineering due to their biocompatibility. To generate biomaterials with a more complete set of biological properties, previously discarded silk sericin (SS) has been recovered and used as a template to grow CaPs. Crucial characteristics for skin applications, such as antibacterial activity, can be further enhanced by doping CaPs with cerium (Ce) ions. The effectiveness of cell attachment and growth on the materials highly depends on their morphology, particle size distribution, and chemical composition. These characteristics can be tailored through the application of oscillatory flow technology, which provides precise mixing control of the reaction medium. Thus, in the present work, CaP/SS and CaP/SS/Ce particles were fabricated for the first time using a modular oscillatory flow plate reactor (MOFPR) in a continuous mode. Furthermore, the biological behavior of both these composites and of previously produced pure CaPs was assessed using human dermal fibroblasts (HDFs). It was demonstrated that both CaP based with plate-shaped nanoparticles and CaP-SS-based composites significantly improved cell viability and proliferation over time. The results obtained represent a first step towards the reinvention of CaPs for skin engineering.

Asunto(s)

Sericinas , Seda , Materiales Biocompatibles/química , Calcio , Fosfatos de Calcio , Humanos , Sericinas/química , Sericinas/farmacología , Seda/química , Piel

RESUMEN

Calcium phosphate-based materials (CaP) have been widely used as bone graft substitutes with a decent osseointegration. However, the mechanism whereby cells function and repair the bone defect in CaP micro-environment is still elusive. The aim of this study is to find the mechanism how osteoclast behaviors mediate bone healing with CaP scaffolds. Recent reports show that behaviors of osteoclast are closely related with osteogenesis, thus we make a hypothesis that active osteoclast behaviors induced by CaP facilitate bone healing. Here, we found a new mechanism that CaP can regulate osteoclast-mediated osseointegration. Calcium phosphate cement (CPC) is selected as a representative CaP. We demonstrate that the osteoclast-mediated osseointegration can be strongly modulated by the stimulation with CaP. An appropriate Ca/P ratio in CaP can effectively promote the RANKL-RANK binding and evoke more activated NF-κB signaling transduction, which results in vigorous osteoclast differentiation. We observe significant improvement of bone healing in vivo, owing to the active coupling effect of osteoclasts. What is more noteworthy is that the phosphate ions released from CaP can be a pivotal role regulating osteoclast activity by changing Ca/P ratio readily in materials. These studies suggest the potential of harnessing osteoclast-mediated osteogenesis in order to develop a materials-manipulated approach for improving osseointegration.