Characterization of host response, resorption, and strength properties, and performance in the presence of bacteria for fully absorbable biomaterials for soft tissue repair

N. F. N. Stoikes, J. R. Scott, A. Badhwar, C. R. Deeken, G. R. Voeller
Hernia 21:771–782
Link to Publication: https://link.springer.com/article/10.1007/s10029-017-1638-3

Abstract

The objective was to evaluate the host response, resorption, and strength properties, and to assess the performance in the presence of bacteria for Phasix™ Mesh (Phasix™) and Gore® Bio-A® Tissue Reinforcement (Bio-A®) in preclinical models.

Methods

In a rat model, one mesh (2 × 2 cm) was implanted subcutaneously in n = 60 rats. Animals were euthanized after 2, 4, 8, 12, 16, or 24 weeks (n = 5/mesh/time point), and implant sites were assessed for host inflammatory response and overall fibrotic repair thickness. In a rabbit model, meshes (3.8 cm diameter) were bilaterally implanted in subcutaneous pockets in n = 20 rabbits (n = 10 rabbits/mesh) and inoculated with 108 CFU clinically isolated methicillin-resistant Staphylococcus aureus (MRSA). One mesh type was implanted per animal. Animals were euthanized after 7 days, and implants were assessed for abscess formation, bacterial colonization, and mechanical strength.

Results

In the rat study, Phasix™ and Bio-A® exhibited similar biocompatibility, although Bio-A® demonstrated a significantly greater inflammatory response at 4 weeks compared to Phasix™ (p < 0.01). Morphometric analysis demonstrated rapid resorption of Bio-A® implants with initially thicker repair sites at 2, 4, 8, and 12 weeks (p < 0.0001), which transitioned to significantly thinner sites compared to Phasix™ at 16 and 24 weeks (p < 0.0001). In the rabbit bacterial inoculation study, Phasix™ exhibited significantly lower abscess score (p < 0.001) and bacterial colonization (p < 0.01), with significantly greater mechanical strength than Bio-A® (p < 0.001).

Conclusions

Host response, resorption, repair thickness, strength, and bacterial colonization suggest a more stable and favorable outcome for monofilament, microporous devices such as Phasix™ relative to multifilament, microporous devices such as Bio-A® over time.

Authors and Funding

This study was funded by C. R. Bard, Inc. (Davol), Warwick, RI. Nathaniel F. N. Stoikes, MD, Corey R. Deeken, PhD, and Guy R. Voeller, MD, FACS are consultants for, and Jeffrey R. Scott, PhD and Amit Badhwar, PhD are employees of C. R. Bard, Inc. (Davol), Warwick, RI.