The physiological response associated with large particles of TCP, HA, and ALCAP implants using raw 264.7 cells

Ceramic materials were introduced as implantable materials in the early 1960s. Currently, there are numerous types of ceramic materials under evaluation as ideal implant devices. The inflammatory responses generated by various calcium phosphate-based ceramics implants have not been clearly evaluated. The current investigation evaluates the response of RAW 264.7 macrophage cells to large particle size (> 38 microns) of hydroxyapatite (HA), tricalcium phosphate (TCP), and aluminum calcium phosphate (ALCAP). RAW 264.7 cells were cultured in a 24 well plate at a density of 1.5 x 10 cells per well. The plates were divided into seven equal groups (n = 6) (control, HA, TCP, ALCAP, ops HA, ops TCP, ops ALCAP). The total protein, maliondialdehyde (MDA), nitric oxide, and cell counts were measured using established lab protocols at 24, 48 and 72 hours of incubation. Cells grown on coverslips were used to evaluate morphological features. The data obtained from this investigation suggested that the nonopsonized particles of ALCAP and TCP materials exhibited an increase in cell number at both the 48 and 72 hour phases. However, a decrease was seen in cell number in all three opsonized groups at 48 and 72 hour phases when compared to the control. As for MDA levels in the opsonized group, all treatments showed an initial increase. Nitric oxide production increased in TCP and ALCAP at the 48-hour phase. Morphological evaluation revealed that upon the exposure of the three different type of ceramic, the cells appeared to be biocompatible.