at both 2 and 6 weeks , several cell layers surrounded the implants : a single layer of macrophages lying along the polymer , a variable number of layers of fibroblasts interspersed with collagen fibrils ( fewer in mice than in rats , and fewer in corticoid treated rats than control rats ) and an outer monolayer of mesothelial cells .
C0007634
cell
C0016030
fibroblasts