The topographical effect of electrospun nanofibrous scaffolds on the in vivo and in vitro foreign body reaction

Abstract

Topographical cues play an important role in influencing cellular behavior and are considered as significant parameters to be controlled in tissue engineering applications. This work investigated the biocompatibility with regard to scaffold architecture and topographical effect of nanofibrous scaffolds on the in vivo and in vitro foreign body reaction. Random and aligned polycaprolactone (PCL) nanofibers were fabricated by electrospinning technique, with diameters of 313 +/- 5 nm and 506 +/- 24 nm, respectively. Primary monocytes isolated from five human donors were cultured on PCL nanofibers, PCL film, and RGD-coated glass in vitro and cell density and morphology was evaluated at time points of day 0 (2 h), day 3, day 7, and day 10. The in vivo study was carried out by implanting PCL nanofibers and film scaffolds subcutaneously in rats to test the biocompatibility and host response at time points of week 1, week 2, and week 4. The in vitro studies revealed that the initial monocyte adhesion on the aligned fiber scaffold was significantly less (p < 0.001) when compared to the random fiber scaffold. The in vivo study showed that the thicknesses of fibrous capsule on fibrous scaffolds were 7.55 +/- 0.54 microm for aligned fibers and 4.13 +/- 0.31 microm for random fibers, which were significantly thinner than that of film implants 37.7 +/- 0.25 microm (p < 0.001). Additionally, cell infiltration was observed in aligned fibrous scaffolds both in vitro and in vivo, while on random fibers and films, distinct fibrous capsule boundaries were found on the surfaces. These results indicate that aligned electrospun nanofibers may serve as a promising scaffold for tissue engineering by minimizing host response, enhancing tissue-scaffold integration, and eliciting a thinner fibrous capsule.

Bone regeneration potential of sub-microfibrous membranes with osteogenic induction of rBMSC for tissue engineering

“…Several works demonstrated that electrospun fibrous membranes showed a minimized foreign body reaction in animal models in vivo, such as rat [15], rabbit [16] and sheep [17]. From our results, all membranes made of the blended polymers showed mild foreign body reaction, and the membrane with PCL had a lower inflammation than others, due to the less acidic products of degradation.…”

Modulation of macrophage phenotype by cell shape

“…The immune response to tissue-engineered scaffold materials is critical to their success, and as such, investigators have explored whether physical factors, such as substrate topology, influence macrophage behavior. Interestingly, it has been observed that surface features indeed affect macrophage morphology and cytokine secretion profiles (31)(32)(33), as well as the overall and fibrotic responses (34), although the mechanisms underlying these responses have so far remained elusive. Our data suggest that topological cues might lead to different macrophage responses by influencing their shape and cytoskeleton.…”

Plasma-functionalized electrospun matrix for biograft development and cardiac function stabilization

“…It has been reported that hydrophilic implants were generally better tolerated by the host [45]. Moreover, fibrous, parallel oriented substrates were shown to reduce pro-inflammatory cytokine production when compared to 2-D films or randomly oriented fibres of the same material [46]. In our current study, we demonstrated that a plasma-coated, hydrophilic cardiac patch presenting parallel oriented fibres does not trigger macrophage invasion when implanted on healthy rat hearts, revealing thus the immune-tolerance of this patch.…”