posted on 2021-08-31, 20:30authored byAndisheh Motealleh, Didem Kart, Michael Czieborowski, Nermin S. Kehr
Biomaterial-associated
infections are a major cause of biomaterial
implant failure. To prevent the initial attachment of bacteria to
the implant surface, researchers have investigated various surface
modification methods. However, most of these approaches also prevent
the attachment, spread, and growth of mammalian cells, resulting in
tissue integration failure. Therefore, the success of biomaterial
implants requires an optimal balance between tissue integration (cell
adhesion to biomaterial implants) and inhibition of bacterial colonization.
In this regard, we synthesize bifunctional nanomaterials by functionalizing
the pores and outer surfaces of periodic mesoporous organosilica (PMO)
with antibacterial tetracycline (Tet) and antibacterial and cell-adhesive
bipolymer poly-d-lysine (PDL), respectively. Then, the fabricated TetPMO-PDL nanomaterials are incorporated into alginate-based
hydrogels to create injectable and 3D-printable nanocomposite (NC)
hydrogels (AlgL-TetPMO-PDL). These bifunctional nanomaterial
and 3D-printable NC hydrogel show pH-dependent release of Tet over
7 days. They also enhance the proliferation of eukaryotic cells (fibroblasts). TetPMO-PDL is inactive in reducing Pseudomonas
aeruginosa, Staphylococcus aureus, and Enterococcus faecalis biofilms.
However, AlgL-TetPMO-PDL shows significant antibiofilm
activity against P. aeruginosa. These
results suggest that the incorporation of TetPMO-PDL into
AlgL may have a synergistic effect on the inhibition of the Gram-negative
bacterial (P. aeruginosa) biofilm,
while this has no effect on the reduction of the Gram-positive bacterial
(S. aureus and E. faecalis) biofilm.