Bioactive Glass-Based Coatings and Modified Surfaces: Strategies for the Manufacture, Testing, and Clinical Applications for Regenerative Medicine - Biological and Biomedical Coatings: Processing and Characterization - page 417

Distilled
water

Polyvinyl
alcohol

(a) (b)

Mixing
(60 ˚C 1 h)

CEL2
particles

PVA/water
solution

Mixing
(RT 1 h)
PU sponge Dipping

(c)

Sponge
infiltration

WD
10.0 mm

HV
15.00 kV

mag
100 x spot 3.1

det
ETD mode SE

pressure
1.56e-4 mbar

Repetition for
4 times Sponge

compression

Drying
at RT

CEL2/PU composite
scaffolds

WD
16.2 mm

mode
SE

det
ETD

HV
15.00 kV

mag
120 x

spot
5.1

vac mode
High vacuum

bit
0 ˚

500 µm
POLITO

FIGURE 9.17
Example of a slurry dipping method used to coat PUR foam scaffolds. (a) Processing flow chart. (b) Uncoated
PUR. (c) Bioactive glass (CEL2 composition-molar composition: 45% SiO 2 , 3% P 2 O 5 , 26% CaO, 7% MgO, 15%
Na 2 O, 4% K 2 O) coated PUR foam scaffold. (From Baino et al., J. Mater. Sci. Mater. Med. , 20(11), 2189-2195, 2009.
With permission [47].)

However, human osteoblast cell cultures indicated that cell attachment and spreading was
slower compared with both Bioglass and Thermanox substrates, which was likely due to
surface roughness and morphology.
45S5 Bioglass ® and antibacterial AgBG* glass powders have been coated onto Mersilk ®
sutures using the slurry (glass particles suspended in deionized water) dipping process
described by Roether et al. [49] (see Figure 9.18). In vitro experiments were carried out
using Staphylococcus epidermidis under both batch and flow conditions. While the tradi-
tional batch culture testing was used to determine the number of viable cells adhered to
the surface, the flow cell was used to visualize attachment and detachment over time.
Under batch conditions of up to 180 min, statistically significant differences were observed
in the colony forming units (CFU) per suture for both the coated and uncoated Mersilk ®
sutures. The results showed that the AgBG coating had the greatest effect on limiting bac-
terial attachment (8 × 10 2 CFU) when compared to the 45S5 Bioglass ® coating (3.2 × 10 3
CFU) and the uncoated Mersilk ® (1.2 × 10 4 CFU). Under flow conditions, differences were
also seen between the coated and uncoated sutures.

* The ability of silver-doped bioactive glass (AgBG) coatings to prevent bacterial colonization on surgical sutures
was investigated.